Dept of Anatomy

DEPT OF ANATOMY

Researcher : Chan CWY

List of Research Outputs

Fu J.D., Kong M.C.W., Rushing S.N., Lieu D.K., Chan C.W.Y., Tse H.F., Wilson K., Chiamvimonvat N., Boheler K.R., Wu J.C., Keller G. and Li R.A., Distinct Roles of MicroRNA-1 and -499 in ventricular specification and maturation of human embryonic stem cells, Fifth International Symposium on Healthy Aging. 2010.

Jiang P., Rushing S.N., Kong M.C.W., Fu J., Lieu D.K., Chan C.W.Y., Deng W. and Li R.A., Electrophysiological Properties of Human induced Pluripotent Stem Cells (iPSCs), Fifth International Symposium on Healthy Aging. 2010.

Jiang P., Rushing S.N., Kong M.C.W., Fu J., Lieu D.K., Chan C.W.Y., Deng W. and Li R.A., Electrophysiological properties of human induced pluripotent stem cells, Am J Physiol Cell Physiol. 2010, 298: 486-495.

Researcher : Chan KC

List of Research Outputs

Chan K.C., Functional characterization of StAR-related lipid transfer domain containing 13 (DLC 2) RhoGAP in the nervous system. 2009, 180 pages.

Researcher : Chan OOC

List of Research Outputs

Chiu K., Zhou Y., Yeung S.C., Lok C.K.M., Chan O.O.C., Chang R.C.C., So K.F. and Chiu J., Up-regulation of crystallins is involved in the neuroprotective effect of wolfberry on survival of retinal ganglion cells in rat ocular hypertension model, Journal of Cellular Biochemistry. 2010, 110: 311-320.

Researcher : Chang RCC

Project Title:	Elucidating the biological mechanisms of autophagy in Alzheimer's disease
Investigator(s):	Chang RCC, Chu LW
Department:	Anatomy
Source(s) of Funding:	General Research Fund (GRF)
Start Date:	01/2007

Abstract:

To investigate how DR adaptor signaling modulates PKR in vitro so that inhibition of both pathways can maximize neuroprotection; to study the relationship of these two pathways and neuroprotection by inhibiting them in vivo; to examine the co-localization of accumulated phospho-PKR and -DR adaptors in postmortem human AD brain tissues; to investigate whether activation these two pathways can be found in plasma lymphocytes of AD patients.

Project Title:	Elucidating the roles of ER stress responses in β-amyloid peptide production and tau phosphorylation as a common pathological pathway
Investigator(s):	Chang RCC, So KF
Department:	Anatomy
Source(s) of Funding:	NSFC/RGC Joint Research Scheme
Start Date:	01/2008

Abstract:

To determine whether endoplasmic reticulum (ER)-stress would stimultaneously trigger Alzheimer-like tau protein phosphorylation and production of β--amyloid peptide; to study whether phyperphosphorylation of tau protein would induce ER-stress forming a vicious cycle; to investigate the activity and the regulation of glycopgen synthase kinase-3α (GSK-3α) and GSK-3β during the ER-stress; to define the roles of GSK-3α in the hyperphosphorylation of tau during the ER-stress.

Project Title:	Significance of molecular signaling for protein translation control in neurodegeneration of amyotrophic lateral sclerosis
Investigator(s):	Chang RCC
Department:	Anatomy
Source(s) of Funding:	Liu Po Shan/Dr Vincent Liu Endowment Fund for Motor Neuron diseases - General Award
Start Date:	03/2008

Abstract:

To investigate the temporal and spatial relationship of neurons bearing mutated SOD1 (G93A) in neuronal apoptosis, autophagy and activation of kinases involved in protein translation control by using live-cell imaging and Western-blot analysis; to examine whether the kinases involved in protein translation control can be the biological target for therapeutic intervention in ALS.

Project Title:	Impact of systemic inflammatory responses on the development of Alzheimer pathology
Investigator(s):	Chang RCC, Yang X, Chiu K, Yu MS
Department:	Anatomy
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	04/2009
Completion Date:	03/2010

Abstract:

The objective of this proposed study is to understand how systemic inflammatory responses lead to the development of Alzheimer pathology in the central nervous system (CNS). Increasing lines of evidence have demonstrated that sytemic infection or chronic inflammatory responses lead to delirium, cognitive impariment and even seizure (Perry et al., 2003; 2007; Teeling and Perry, 2008). Systemic inflammatory responses may not cause massive neuronal loss in the brain. Instead, loss of synaptic proteins or disturbance of axonal transport may impair neuronal communications leading to delirum and cognitive dysfunctions. Delirium is a transient disorder of cognition and attention and is a recognized consequence of systemic infection in the elderly (George et al., 1997). Interleukin-10 (IL-10) has been considered to be anti-inflammatory cytokine. IL-10 knockout mice has been shown to induce systemic inflammatory responses starting from the gastrointestinal tract (Rennick et al., 1995). Taken the results from literature and our own experience, we hypothesize that chronic and acute systemic inflammation will trigger microglia to amplify CNS inflammatory responses to induce Alzheimer pathology (accumulation of β-amyloid peptide and tau hyperphosphorylation), followed by disturbance of syanpses and axonal transport. Therefore, we will use two animal models (IL-10 knockout mice and intraperitoneal injection of bacterial endotoxin lipopolysaccharide) to investigate how systemic inflammation affects tau protein phosphorylation and induces accumulation of β-amyloid (Aβ) peptides in the hippocampus. In addition, we will examine synaptic proteins as well as acetylation of microtubule (stability of microtubule). To further investigate whether cytokines directly affect neurons or the induced Alzheimer pathological factors (intracellular Aβ and phosphorylated tau protein) affect neuron. We will use primary cultured hippocampal neurons as second experimental model. Upon cytokine stress, we will examine synaptic proteins and stability of microtubules. To achieve our goal, we separate our study into three specific aims: 1. To investigate how chronic systemic inflammation in IL-10 knockout mice can induce Alzheimer pathology (accumulation of intracellular β-amyloid peptide and phosphorylation of tau). 2. To investigate if acute systemic infection generated by intraperitoneal injection of bacterial endotoxin lipopolysaccharide (LPS) into normal wild-type and IL-10 knockout mice induce Alzheimer pathology in the brain. 3. To use primary cultured of hippocampal neurons to investigate whether cytokines can affect distribution of synaptic proteins and axonal transport. It has been considered that systemic inflammation greatly increases the risk of relapsing multiple sclerosis (MS) and triggers delirium in patients with Alzheimer’s disease (AD) (Perry et al., 2003; 2007; Teeling and Perry, 2008). Systemic increase of cytokines can induce cytokines production in the CNS, which is not related to the break down of blood-brain-barrier (BBB). As a consequence, cytokines in the CNS may affect relaspse of MS and delirium in AD. This is a new area combining neuroimmunology and neurodegeneration, which has not been fully explored but is important to determine disease progression of neurodegeneration. PI is an expertise in both research areas. Therefore, it is appropriate for PI to explore this new but important field because it may explain the pathogenesis of neurodegeneration. As a seed funding, we focus ourselves on the pathological changes for developing AD. In fact, it has been reported that systemic infection can induce cognitive dysfunctions nad behavioral change in experimental mice (Cunningham et al., 2008). In addition, systemic challenge of mice with synthetic double-stranded RNA (poly I:C) as a product of viral infection also cause sickness behavior (Cunningham et al., 2007). Disturbance of cognition by systemic infection does not just occur in experimental animal. Indeed, patients suffering upper respiratory tract infection also show cognitive dysfunction (Bucks et al., 2008). In Hong Kong, children hospitalized with influenza have higher rate of neurologic complication (20%) than that in the US (8.5%) (Chung et al., 2007). Cytokines cannot pass through the BBB. Then, how systemic inflammation modulates CNS cytokines production. First, inflammation in the abdominal cavity can signal the brain via vagal-nerve. Second, cytokines, inflammatory factors and macrophages can communicate with microglial cells (brain macrophages) in the circumventricular organs where BBB is absent. Third, cytokines and inflammatory factors can modulate brain endothelial cells (cells forming BBB) to produce cyclooxygenase 2 (COX2) and/or prostaglandin E2, which can then activate microglial cells in the CNS (Perry et al., 2007). All these three routes can transmit the inflammatory signals from systemic to the CNS and inflammtory signals can be amplified by activation of microglia. While increasing lines of evidence have demonstrated relationship between cognitive dysfunction, delirium and systemic infection, little is known about pathophysiological and anatomical changes of neurons. Therefore, we take this new initiative to investigate whether accumulation of intracellular Aβ peptide and tau hyperphosphorylation occur in the hippocampus of mice having systemic inflammation (IL-10 knockout mice or mice with intraperitoneal injection of LPS). It has been known that accumulation of intracellular Aβ can affect synapses and axonal transport (LaFerla et al., 2007). Therefore, we will also examine synaptic proteins (synaptophysin as pre-synaptic proteins and PSD-95 and Drebrin as post-synaptic proteins). Having done the animal experiments, we will use primary cultures of hippocampal neurons to investigate whether cytokines themselves can modulate synaptic proteins and axonal transport.

Project Title:	Investigating the efficacy of minocycline as neuroprotective agent against cytokine storm-mediated neurotoxicity
Investigator(s):	Chang RCC, Ho YS
Department:	Anatomy
Source(s) of Funding:	Research Fund for the Control of Infectious Diseases - Full Grants
Start Date:	10/2009

Abstract:

To elucidate the efficacy of neuroprotective minocycline in cytokine storm. Firstly, we will investigate whether minocycline protects neurons from systemic cytokine storm in experimental animals. Secondly, we will investigate whether minocycline protect neurons from locally occurred cytokine storm in the CNS in experimental animals. Thirdly, we will investigate how minocycline affects synaptic proteins and axonal transport on cultured hippocampal neurons.

Project Title:	Neuroscience 2009 Alzheimer-like pathology in rat receiving passive smoking Polysaccharides from Wolfberry (Lycium barbarum) antagonize
Investigator(s):	Chang RCC
Department:	Anatomy
Source(s) of Funding:	URC/CRCG - Conference Grants for Teaching Staff
Start Date:	10/2009
Completion Date:	10/2009

Abstract:

N/A

Project Title:	Alzheimer's Disease Conference: From Public Health to Therapeutic Insights
Investigator(s):	Chang RCC
Department:	Anatomy
Source(s) of Funding:	France/Hong Kong Joint Research Scheme - Conference/Workshop Grants
Start Date:	01/2010

Abstract:

Refer to hard copy

Project Title:	Elucidating the pathophysiological significance of endoplasmic reticulum aggregation in neurons stressed by ?amyloid peptide and in Alzheimers disease'
Investigator(s):	Chang RCC, Wu W
Department:	Anatomy
Source(s) of Funding:	General Research Fund (GRF)
Start Date:	01/2010

Abstract:

1) To investigate whether ER aggregation in morphological study equivalents to dysfunctions of the ER by examining ER-associated degradation (ERAD) pathway, calcium storage and ER-retention proteins; 2) To examine whether aggregation of the ER leads to the formation of autophagic vacuoles or lysosomes. Also, we will investigate the fate of neurons if autophagy/lysosomes systems are impaired; 3) To examine whether increased numbers of lysosomes will result in increased production of Aβ peptide.

Project Title:	Establishing a Logistic Screening Platform for Stilbene and its Derivatives from Functional Food as Potential Neuroprotective Drug Leads in Parkinson's Disease
Investigator(s):	Chang RCC, Wang M
Department:	Anatomy
Source(s) of Funding:	Seed Funding Programme for Applied Research
Start Date:	01/2010

Abstract:

Objective: The objective of this proposed study is to establish a logistic platform to screen different stilbenes from functional food (food claimed to be health-promoting), so that we can find a good neuroprotective drug against neurodegeneration in PD. Collaborative efforts from both PI and co-I have proved that this class of molecules has great potential in protecting dopaminergic neurons against parkinsonism mimetic such as 6-hydroxydopamine (6-OHDA) and 1-methy-4-phenylpyridinium (MPP+). Our collaborative results lead us to pursue more potential neuroprotective drugs from different derivatives of stilbene extracted from functional food, as long as we have a logistic screening platform. PI has long worked on the roles of stress kinases and intracellular organelles (mitochondria and endoplasmic reticulum) in neurodegeneration. He has established the techniques of investigating stress kinases and dynamic of mitochondria. However, we have not aligned different technological platforms to logistically examine neuroprotective drugs from functional food, and to formulate a translational research. More recently, an opportunity arrives with the new establishment of a R&D site from GlaxoSmithKline (GSK), the second largest pharmaceutical company in the world, in China for R&D aiming to develop drug in neurodegeneration. This is a golden opportunity for us to establish a logistic screening platform for small molecules from functional food and to develop neuroprotective drug against neurodegeneration in PD. It has long been demonstrated that resveratrol (trans-3’,4,5’-trihydroxystilbene belonging to a class of stilbene) extracted from red wine provides anti-oxidative effects against toxins in different neurological disorders. Its anti-oxidative property is mostly attributed to its polyphenolic structure. This type of compound has been proved to be neuroprotective against β-amyloid peptide in Alzheimer’s disease and MPTP in PD. However, this type of compound can also function as oxidant to fight against cancer cells, leading to apoptosis of cancer cells. Therefore, this type of compound can be toxic to neurons if inappropriate dosage is employed. Indeed, our experimental data using in vitro culture system can demonstrate that the effective dosages of neuroprotective resveratrol are narrow. In view of the toxic effects of resveratrol, we have recently discovered that its analog, oxyresveratrol (trans-2,4,3’,5’-tetrahydroxystibene), provides a wider effective dosages of neuroprotection than that of resveratrol (Chao et al., 2008). In addition, oxyresveratrol can be extracted from natural food like mulberry from co-I (Li et al., 2007). He has different know-how to isolate different derivatives of stilbene and examine the pharmacokinetic of this class of molecules by HPLC. Furthermore, we have found that methylated derivative of resveratrol, pinostilbene, is more effective to elicit neuroprotective effects than that of oxyresveratrol (Chao et al., 2009). Therefore, we have planned this proposed study to extend our screening for this class of small molecules and their derivatives. We will then be able to understand the structure-function relationship of this class of molecules as neuroprotective drug against neurodegeneration in PD. However, there is no logistic screening platform to screen the neuroprotective drug for PD research from food extract. The successful of screening rely on basic science research on biological targets. Problem to be addressed: PI has worked on stress kinases including the c-Jun N-terminal kinase (JNK), extracellular signal regulated protein kinase (ERK) and protein kinase B/Akt on neurodegeneration. It has been reported and even has been reviewed that all these kinases can be translocated into mitochondria. Together with what have been known about PTEN-induced kinase 1 (PINK1), α-synuclein and leucine rich repeat kinase 2 (LRRK2), all these stress and PD-related kinases play important roles in determining the fate of mitochondria (Dagda et al., 2009). As mitochondria are important organelle producing energy for neurons and are easily to induce oxidation because of the metabolism of oxidative phosphorylation (electronic transport chain) to produce ATP, and dopaminergic neurons in the striatum and substantia nigra are very sensitive and vulnerable to oxidative damage, mitochondria become the major biological target for preserving dopaminergic neurons in PD rather than in other neurodegenerative diseases. Apart from the stress kinases associated and/or translocated into mitochondria, the dynamic movement (fission and fusion) of mitochondria becomes an important index for the fate of mitochondria (Büeler, 2009). Extensive fission or fragmentation of mitochondria is often associated with degenerative process of neurons. Therefore, the logistic arrangement of screening is to focus the biochemical and dynamic of mitochondria. Since there is no such logistic platform to screen neuroprotective drug from functional food, the logistic in this proposed study is a proof-of-concept research to demonstrate that we can discover neuroprotective drug for PD. Afterwards, we can transform this kind logistic screening into high throughput screening.

Project Title:	Elucidating the biological mechanisms of transforming autophagy into apoptosis in hippocampal neurons exposed to low molecular weight beta-amyloid peptide
Investigator(s):	Chang RCC, Ho YS
Department:	Anatomy
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	04/2010

Abstract:

Objective: The objective of this proposed study is to elucidate the biological mechanisms of how autophagy is transformed into neuronal apoptosis in β-amyloid (Aβ) peptide neurotoxicity in hippocampal neurons. It has been known that both autophagy and neuronal apoptosis are two different modes of neurodegeneration. Moreover, autophagy has recently been considered to be a survival tool for neurons to prolong life. Our pilot results also direct us to consider that autophagy allows neurons to struggle for survival after challenged by Aβ. We have recently published our results by showing that low molecular weight (LMW) Aβ peptide induces aggregation and collapse of the endoplasmic reticulum (ER) and results in formation of autophagic vacuoles. We further have concrete results to demonstrate that autophagic vacuoles are derived from ER by using an omegasomes construct. Recently, we have found imbalance of fission and fusion of mitochondria (dynamic of mitochondria) at nearly the same time of ER aggregation. The results agree with other reports showing the impaired dynamic of fission and fusion of mitochondria. However, we could not detect any damaged mitochondria in autophagic vacuoles. Therefore, we hypothesize that impaired mitochondrial dynamic will transform neurons from autophagy into apoptosis, forcing neurons undergoing the final step of neurodegeneration. Nevertheless, we do not anticipate that mitochondrial dysfunction is the only player leading neurons to neuronal apoptosis. We have also found that activation of a novel pro-apoptotic signaling pathway (e.g. death-associated protein kinase, DAPK) and impaired ubiquitin proteasomes system (UPS) / lysosomal degradation pathways can attribute to the transition of autophagy into neuronal apoptosis. To prove our hypothesis, we have three specific aims for this study: 1. To investigate whether activation of DAPK will facilitate the transition of autophagy into neuronal apoptosis in cultured hippocampal neurons exposed to LMW Aβ peptide; 2. To investigate how impaired fission and fusion of mitochondria leads to their dysfunctions resulting in neuronal apoptosis; 3. To investigate whether impaired UPS/lysosomal degradation (clearance of autophagic vacuoles and misfolded proteins) will lead to transforming autophagy into neuronal apoptosis. Problem to be addressed: It has been known that neuronal apoptosis may be the final journey of neurodegeneration in Alzheimer’s disease (AD). However, massive neurons loss will not occur in a short period of time. Identification of autophagy has been considered to be one mode of neurodegeneration. However, recent findings including the data from PI’s laboratory has shown that autophagy may be a tool for neurons to struggle for survival. A big knowledge gap and question in this field is how autophagy is transformed into neuronal apoptosis. Our recent work has provided us several hints to tackle this question. As far as we know, aggregation of the ER is not the priming factor to transform autophagy into apoptosis. It appears that the time for the activation of DAPK matches the time for initiation of neuronal apoptosis. Inhibition of UPS/lysosomal degradation to impair the clearance of autophagic vacuoles has been considered to be an important factor in neurodegeneration of AD. All these preliminary results and reports give us opportunity to further explore the underlying mechanisms of transforming autophagy into neuronal apoptosis. Support from this seed funding will allow us to focus on one particular pathway for the future GRF or external grant application next year. Therefore, it is necessary for us to explore potential of these three possible pathways in order to be streamlined in a next tier of external grant application.

List of Research Outputs

Chang R.C.C., Yang X., Ho Y.S., Yeung S.C. and Mak J.C.W., Alzheimer-like pathology in rat receiving passive smoking, Society for Neuroscience 2009. Program No. 626.13: Poster No. H26.

Chang R.C.C., Cellular Organization of the Central Nervous System, The 6th HKU-Pasteur Virology Course: Focus on Neurotrophic Virus. 2009.

Chang R.C.C., Chairman, Organizing Committee, Alzheimer's Disease Conference: From Public Health to Therapeutic Insights. 2010.

Chang R.C.C., Editorial Board Member, American Journal of Alzheimer's Disease and Other Dementia. 2010.

Chang R.C.C., Editorial Board Member, Automated Experimentation. 2009.

Chang R.C.C., Editorial Board Member, Chinese Medicine. 2010.

Chang R.C.C., Editorial Board Member, The Open Enzyme Inhibition Journal. 2010.

Chang R.C.C., Editorial Board Memeber, Automated Experimentation. 2010.

Chang R.C.C., Editorial Board Memeber, International Journal of Clinical and Experimental Medicine. 2010.

Chang R.C.C., Handling Associate Editor, Journal of Alzheimer's Disease. 2010.

Chang R.C.C., Ho Y.S., Yu M.S. and So K.F., Medicinal and nutraceutical uses of wolfberry in preventing neurodegeneration of Alzheimer's disease, In: Charles Ramassamy and Stéphane Bastianetto, Recent Advances on Nutrition and the Prevention of Alzheimer's Disease, 2010. Kerala, India, Transworld Research Network, 2010, 169-185.

Chang R.C.C., Chiu K., Ho Y.S. and So K.F., Modulation of neuroimmune responses on glia in the central nervous system: implicaion in therapeutic intervention against neuroinflammation, Cellular and Molecular Immunology. 2009, 6(5): 317-326.

Chang R.C.C., Chao J., Ho Y.S. and Wang M., Neurodegeneration: the Processes, Hong Kong Medical Journal. 2009, 15(6) Suppl. 7.

Chang R.C.C., Neurodegeneration: the processes, 1st Hong Kong Neurological Congress. 2009.

Chang R.C.C., Neurodegeneration, The 6th HKU-Pasteur Viruology Course: Focus on Neurotrophic Virus.. 2009.

Chang R.C.C., Chao J., Yu M.S. and Wang M., Neuroprotective effects of oxyresveratrol from fruit against neurodegeneration in Alzheimer's disease, In: Charles Ramassamy and Stéphane Bastianetto, Recent Advances on Nutrition and the Prevention of Alzheimer's Disease, 2010. Kerala, India, Transworld Research Network, 2010, 155-168.

Chang R.C.C., Pathogenesis and Autophagy of Alzheimer's Disease, Alzheimer's Disease Conference: From Public Health to Therapeutic Insights. 2010.

Chang R.C.C., Zhang Q., Hung H.L., Cheung Y.T., Ho Y.S., Lai S.W. and Wuwongse S., Pathogenesis of Alzheimer's Disease, 5th International Symposium on Healthy Aging. 2010, Page 19.

Chang R.C.C., Pathogenesis of Alzheimer's Disease, The 5th International Symposium on Healthy Aging: Is Aging a Disease?. 2010.

Chang R.C.C., Searching for neuroprotective agents for Parkinson's disease from food extract: Partnership with food scientist, Workshop on Strategic Research Theme on Drug. 2009.

Chang R.C.C., Session Chairman, The 5th International Symposium of Healthy Aging. 2010.

Chang R.C.C., 從醫學基礎研究到保健產品談老年癡呆症：你我知多少？, In: L.K. Lam et.al., 育醫造才：探索醫學世界 (Explore the World of Medicine). Hong Kong, The University of Hong Kong Li Ka Shing Faculty of Medicine, 2010, 76-78.

Chao J., Lau K.W., Huie M.J., Ho Y.S., Yu M.S., Lai S.W., Wang M., Yuen W.H., Lam W.H., Chan T.H. and Chang R.C.C., A pro-drug of the green tea polyphenol (-)-epigallocatechin-3-gallate (EGCG) prevents differentiated SH-SY5Y cells from toxicity induced by 6-hydroxydopamine, Neuroscience Letters. 2010, 469: 360-364.

Chao J., Li H., Cheng K.W., Yu M.S., Wang M. and Chang R.C.C., Neuroprotective effects of methylated resveratrols in an vitro Parkinson's disease model , Society for Neuroscience 2009. Program No. 144.2: Poster No. G10.

Chao J., Cheng K.W., Yu M.S., Chang R.C.C. and Wang M., Protective effect of pinostilbene, a resveratrol methylated derivative against 6-hydroxydopamine-induced neurotoxicity in SH-SY5Y Cells, Journal of Nutritional Biochemistry. 2010, 21: 482-489.

Chao J., Li H., Cheng K.W., Yu M.S., Wang M. and Chang R.C.C., Resveratrol methylated derivatives as neuroprotective agents in 6-hydroxydopamine-induced SH-SY5Y cells, 5th International Symposium on Healthy Aging. 2010, Page 53.

Cheung Y.T., Zhang N.Q., Hung C.H.L., Lai S.W., Yu M.S. and Chang R.C.C., Autophagy may protect neurons from low molecular weight beta-amyloid peptide-induced apoptosis, 5th International Symposium on Healthy Aging. 2010, Page 58.

Cheung Y.T., Zhang Q., Hung H.L., Lai S.W., Yu M.S., So K.F. and Chang R.C.C., Investigating the temporal transition of autophagy and apoptosis in neurons stressed by low molecular weight beta-amyloid peptide toxicity, 11th International Geneva/Springfield Symposium on Advances in Alzheimer Therapy, March 24-27, 2010 Geneva. 2010, 42.

Cheung Y.T., Lau K.W. and Chang R.C.C., What do we need to concern in using cell line for neurotoxicology research, differentiation or disturbance of intracellular signaling?, NeuroToxicology. 2009, 31: 164-166.

Chiu K., Yeung S.C., Ho Y.S., Lok C.K.M., Chan W., So K.F. and Chang R.C.C., IL-10 improves retinal ganglion cell survival in experimental glaucoma model via up-regulation of IGF-1 signaling, Hong Kong Society for Immunology 2010 Annual General Meeting and Scientific Meeting, April 17, 2010.. 2010, 14.

Chiu K., Yeung S.C., So K.F. and Chang R.C.C., Modulation of morphological changes of microglia and neuroprotection by monocyte chemoattractant protein-1 in experimental glaucoma, Cellular and Molecular Immunology. 2010, 7: 61-68.

Chiu K., Zhou Y., Yeung S.C., Lok C.K.M., Chan O.O.C., Chang R.C.C., So K.F. and Chiu J., Up-regulation of crystallins is involved in the neuroprotective effect of wolfberry on survival of retinal ganglion cells in rat ocular hypertension model, Journal of Cellular Biochemistry. 2010, 110: 311-320.

Ho Y.S., So K.F. and Chang R.C.C., Anti-aging herbal medicine - How and why can they be used in aging-associated neurodegenerative disease?, Ageing Research Reviews. 2010, 9: 354-362.

Ho Y.S., Yu M.S., Yang X., So K.F., Yuen W.H. and Chang R.C.C., Neuroprotective effects of polysaccharides from wolfberry, the fruits of Lycium barbarum. against homocysteine-induced toxicity in rat cortical neurons, Journal of Alzheimer's Disease. 2010, 19: 813-827.

Ho Y.S., Yang X., Yu M.S., So K.F. and Chang R.C.C., Polysaccharides from Wolfberry (Lycium barbarum) antagonize homocysteine-induced neurotoxicity in cultured cortical neurons, Society for Neuroscience 2009. Program No. 626.3: Poster No. H16.

Ho Y.S., Yu M.S., Yik S.Y., So K.F., Yuen W.H. and Chang R.C.C., Polysaccharides from wolfberry antagonizes glutamate excitotoxicity in rat cortical neurons, Cellular and Molecular Neurobiology. 2009, 29: 1233-1244.

Ho Y.S., Yang X., Wang J., So K.F. and Chang R.C.C., The relationship between ER stress and TAU phosphorylation - Do they affect each other?, 5th International Symposium on Healthy Aging,. 2010, Page 63.

Ho Y.S., So K.F. and Chang R.C.C., Wolfberry (Lycium Barbarum) protects primary corticol neurons against Alzheimer's disease-related pathological damages, Collegium Internationale Neuro-Psychopharmacologicum (CINP) 2010 World Congress. 2010, P-08.

Hong S.J., Chiu K., Ho Y.S., He Y., Che C.T., So K.F., Lin Z.X. and Chang R.C.C., Significance of chrysin from a cognitive-enhanching chinese herb Alphinae oxyphyllae as a source of potential neuroprotective agent, 5th International Symposium on Healthy Aging. 2010, Page 54.

Hugon J., Paquet C. and Chang R.C.C., Could PKR inhibition modulate human neurodegeneration?, Expert Review of Neurotherapeutics. 2009, 9(10): 1455-1457.

Hung C.H.L., Cheung Y.T., Ho Y.S. and Chang R.C.C., Intracellular organelle collapse triggered by low molecular weight b-amyloid peptides, 5th International Symposium on Healthy Aging. 2010, Page 61.

Hung H.L., Ho Y.S. and Chang R.C.C., Modulation of mitochondrial calcium as a pharmacological target for Alzheimer's disease, Ageing Research Reviews. 2010, 9: 447-456.

Jia H.S., Lin X., He Y., Che C.T., Ho Y.S. and Chang R.C.C., The neuroprotection effects of a cognitive-enhancing herb Alpinae Oxyphyllae and its component chrysin on glutamate-induced neurotoxicity, Society for Neuroscience 2009. Program No. 626.16: Poster No. H29.

Lau W.M., Yau S.Y., Lee C.D., Chang R.C.C. and So K.F., Effect of Lycium Barbarum (Wolfberry) polysaccharide on sexual behavior of male rats, Collegium Internationale Neuro-Psychopharmacologicum (CINP) 2010 World Congress. 2010, P-02.

Lau W.M., Yau S.Y., Lee C.D., Chang R.C.C. and So K.F., Lycium barbarum (wolfberry) polysaccharide facilitates ejaculatory behaviour in male rats. , Annual Meeting of the Australian Neuroscience Society. 2010.

Li S.Y., Yeung C.M., Yu W.Y., Chang R.C.C., So K.F., Wong D.S.H. and Lo A.C.Y., Beneficial effects of lycium barbarum polysaccharides on neurons and blood-retinal barrier in retinal ischemia/reperfusion injury, 5th International Symposium on Healthy Aging. 2010, Page 59.

Li S.Y., Yeung C.M., Chang R.C.C., So K.F., Wong D.S.H. and Lo A.C.Y., Lycium Barbarum Polysaccharides Protects Retina From Ischemia/reperfusion Injury, ARVO 2010 Annual Meeting. 2010.

Li S.Y., Yeung C.M., Yu W.Y., Chang R.C.C., So K.F., Wong D.S.H. and Lo A.C.Y., Protection Of Retinal Neurons By Administration Of Lycium Barbarum (wolfberry) In A Murine Model Of Acute Ischemia/reperfusion Injury, Joint Annual Scientific Meeting of the Hong Kong Society of Neurosciences and the Biophysical Society of Hong Kong. 2010.

Lo A.C.Y., Yeung C.M., Li S.Y., Chang R.C.C., So K.F. and Wong D.S.H., Neuroprotective effects of Lycium barbarum polysaccharides on ischemic stroke injury, Society for Neuroscience 2009. Program No. 150.13: Poster No. K2.

Mi X., Chiu K., Van G., Leung J.W.C., Lo A.C.Y., Chung S.K., Chang R.C.C. and So K.F., The effect of lycium barbarum (wolfberry) on the expression of endothelin-1 and its receptors in an ocular hypertension model of glaucoma, 5th International Symposium on Healthy Aging. 2010, Page 55.

Peng X., Ma J., Chao J., Sun Z., Chang R.C.C., Tse I., Li E.T.S., Chen F. and Wang M., Beneficial effects of cinnamon proanthocyanidins on the formation of specific advanced glycation endproducts and methylglyoxal-induced impairment on glucose consumption, Journal of Agricultural and Food Chemistry. 2010, 58: 6692-6696.

So K.F. and Chang R.C.C., Molecular mechanism of neuroprotection in glaucoma using gouqizi (wolfberry), 首都医科大学眼科学院２００９年学朮年会. 2009, 10.

So K.F. and Chang R.C.C., Molecular mechanism of neuroprotection in glaucoma using gouqizi (wolfberry), Hong Kong Journal of Ophthalmology. 2009, 13(1): 8.

So K.F. and Chang R.C.C., Molecular mechanism of neuroprotection in neurodegenerative diseases using gouqizi (wolfberry), 7th AMN Congress and 16th Annual Scientific Meeting of HKNS, Nov. 12-14, 2009 Hong Kong. 2009, 67.

Wuwongse S., Hung H.L., Law A.C.K. and Chang R.C.C., Corticosterone induced synaptic degeneration in depression and Alzheimer's disease, Collegium Internationale Neuro-Psychopharmacologicum (CINP) 2010 World Congress. 2010, P-09.

Wuwongse S., Chang R.C.C. and Law A.C.K., Exploriing the Connection between Depression and Dementia, HKU 14th Research Postgraduate Symposium, Hong Kong (December 2-3, 2009). 2010.

Wuwongse S., Law A.C.K. and Chang R.C.C., Investigating synaptic degeneration as common pathophysiological factor in depression and Alzheimer's disease, 11th International Geneva/Springfield Symposium on Advances in Alzheimer Therapy, March 24-27, 2010 Geneva. 2010, 87.

Wuwongse S., Chang R.C.C. and Law A.C.K., Investigation of synaptic degeneration in depression and Alzheimer's disease, 5th International Symposium on Healthy Aging. 2010, Page 52.

Wuwongse S., Chang R.C.C. and Law A.C.K., The potential effects of antidepressants in attenuating synaptic degeneration in depression and Alzheimer's disease, 18th European Congress of Psychiatry, Munich, Germany (February 28 - March 2, 2010). 2010.

Yang D., Yeung C.M., Li S.Y., Chang R.C.C., So K.F., Wong D.S.H. and Lo A.C.Y., Lycium Barbarum Polysaccharides Protects Brain From Ischemia/reperfusion Injury, Joint Annual Scientific Meeting of the Hong Kong Society of Neurosciences and the Biophysical Society of Hong Kong. 2010.

Yu H.T., Chan W.W.L., Chai K.H., Lee C.W.C., Chang R.C.C., Yu M.S., McLoughlin D.M., Miller C.C.J. and Lau K.F., Transcriptional regulation of human FE65, a ligand of Alzheimer's disease amyloid precursor protein, by Sp1, Journal of Cellular Biochemistry. 2010, 109: 782-793.

Yu J.T., Chang R.C.C. and Tan L., Calcium dysregulation in Alzheimer's disease: From mechanisms to therapeutic opportunities, Progress in Neurobiology. 2009, 89: 240-255.

Zhang E., Yau S.Y., Lau W.M., So K.F. and Chang R.C.C., Anti-depressive effects of Lycium Barbarum in a rat depression model, Collegium Internationale Neuro-Psychopharmacologicum (CINP) 2010 World Congress. 2010, P-09.

Zhang E., Chang R.C.C. and So K.F., Elucidating beneficial effects of Wolfberry (Lycium barbarum) in experimental depression, Society for Neuroscience 2009. Program No. 549.13: Poster No. X7.

Zhang N.Q., Cheung Y.T., Ho Y.S. and Chang R.C.C., Impact of low molecular weight Ab on autophagosomes and proteasomes via collapse of the endoplasmic reticulum, 5th International Symposium on Healthy Aging. 2010, Page 61.

Zhu Q., Zheng Z., Chao J., Chang R.C.C. and Wang M., Protective effects of natural polyphenols in acrolein-induced cytotoxicity, 5th International Symposium on Healthy Aging. 2010, Page 53.

Researcher : Chau RMW

Project Title:	HUGO's Seventh International Human Genome Meeting, HGM2002 The Possible Mechanism of Action for Quinacrine Interacting the Scrapie Protein in Prion Disease
Investigator(s):	Chau RMW
Department:	Anatomy
Source(s) of Funding:	URC/CRCG - Conference Grants for Teaching Staff
Start Date:	04/2002

Abstract:

N/A

Researcher : Chen AYS

Project Title:	Study of the role of polyol pathway activation the impaired nerve regeneration in diabetes
Investigator(s):	Chen AYS, Chung SK
Department:	Anatomy
Source(s) of Funding:	Small Project Funding
Start Date:	12/2008

Abstract:

The pathogenesis of diabetic neuropathy is still unclear. Impaired nerve regeneration has been believed to be one of the important pathogenetic mechanisms of diabetic neuropathy. This project is to investigate the role of polyol pathway activation in the impaired nerve regeneration in diabetes.

List of Research Outputs

Chen A.Y.S., Chung S.S.M. and Chung S.K., Aldose reductase deficiency improves wallerian degeneration and nerve regeneration in diabetic thy1-YFP mice, Journal of Neuropathology & Experimental Neurology:. 2010, 69(3): 294-305.

Researcher : Cheung A

Project Title:	Centromeric instability in human cells undergoing immortalization: implication for progression of chromosomal instability in carcinogenesis
Investigator(s):	Cheung A, Tsao GSW, Guan XY, Deng W
Department:	Anatomy
Source(s) of Funding:	General Research Fund (GRF)
Start Date:	01/2007
Completion Date:	12/2009

Abstract:

To investigate whether centromeric instability is a general phenomenon in human cells undergoing immortalization; to study the mechanisms underlying centromeric instability in human cells undergoing immortalization.

Project Title:	Cornulin as a novel candidate tumor suppressor gene in esophageal cancer
Investigator(s):	Cheung A, Tsao GSW
Department:	Anatomy
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	01/2008
Completion Date:	06/2010

Abstract:

Human cancers develop through a multistage process involving changes in expression or mutation of oncogenes or tumor suppressor genes. Apart from the genetic alterations, accumulating evidence suggests that the development of human cancer is a tissue-specific process involving an interaction between mutated cells and the unique conditions within a particular local matrix and microenvironment. The epithelium of the esophagus is exposed directly to a range of relatively unique stresses including thermal injury, refluxed acid and bile salts. Considering that the effects of the oncogenes and tumor suppressor genes often depend on the cell type in which they are expressed [1], the importance of cancer type-specific oncogenes and tumor suppressor genes warrants investigation, but the identities of esophageal cancer-specific oncogenes and tumor suppressor genes are now only beginning to be unraveled. The discovery of the cornulin gene has added a novel gene to the list of very few esophageal cancer-specific genes identified. Cornulin, also know as chromosome 1 open reading frame 10 (C1orf10), is a recently identified gene encoding a protein with a conserved S100 EF-hand calcium-binding motif, and was found to be highly expressed only in the esophagus and undetectable in a total of 15 other normal human adult tissues [2]. Cornulin locates at chromosome 1q21 within the epidermal differentiation complex fused-gene family, which often exhibits loss of heterozygosity (LOH) in esophageal cancer [3, 4]. Its expression is known to be down-regulated in esophageal squamous cell carcinoma (ESCC) [2]. More interesting is that in human esophageal squamous epithelium, cornulin responds to heat shock [5], which is one of the risk factors unique for esophageal cancer. These findings suggest a potential role of cornulin as a specific tumor suppressor gene in esophageal cancer. But up to now, the function of cornulin in esophageal cancer is unknown. In this project, we aim to study the functional roles of cornulin in the development of esophageal cancer and the mechanisms involved. The effects of ectopic expression of cornulin on esophageal cancer cell growth, sensitivity to chemotherapy drugs, cell cycle regulation, and the PI3K/Akt signaling pathway, will be investigated in a pilot study. The objectives of this study are: 1. To study the tumor suppressor effects of cornulin in esophageal cancer cells Rationale: The specific expression pattern of cornulin in the normal esophagus and its down-regulation in esophageal cancer, as well as its response to heat shock (one of the risk factors unique for esophageal cancer development), led us to hypothesize that cornulin may play a suppressive role in the initiation, promotion and progression of esophageal cancer. The presence of an EF-hand calcium-binding motif similar to S100 protein family corroborates our hypothesis, because previous studies indicated that S100 proteins, like cornulin, have tissue- and cell type-specific expression patterns and some of them are involved in cancer. However, the functions of cornulin in esophageal cancer have not been reported. Since we have obtained three expression vectors as follows: (a) full-length cornulin, (b) cornulin with deletion of the EF-hand motif (cornulin-ΔEF), (c) EF-hand motif alone (EF-hand), we can use a gain-of-function approach to validate the tumor suppressor role of cornulin in esophageal cancer cells lacking cornulin expression. Through the stable transfection of these vectors, the effects of cornulin and the EF-hand motif on cell growth, apoptosis and in vitro transformation phenotype can be determined. Furthermore, the responses of the stable clones to chemotherapy drugs commonly used to treat esophageal cancer can be compared to determine the effects of cornulin on cancer drug resistance. This objective therefore serves to establish a correlation between cornulin and development of esophageal cancer and can be expanded to include loss-of-function studies once an external grant is secured. 2. To study the effects of cornulin on cell cycle regulation Rationale: Progression of the cell cycle is governed by checkpoints that control the correct order and completion of the previous phase before the cell can enter into the next phase of the cell cycle. In normal cells, the cell cycle is a highly conserved, tightly regulated cellular process. In cancer cells, however, this regulation is always disturbed. The cyclin D1-CDK4/6-Rb pathway, for example, is crucial in regulating the G1/S phase checkpoint. Phosphorylation of Rb by the cyclinD1-CDK4/6 complex causes the inactivation of Rb and release of E2F, leading to the transition of G1 to S phase. It has been reported that induction of cornulin expression results in G1/S cell cycle arrest and a down-regulation of cyclin D1 in oral squamous cell carcinoma [6]. We postulate that cornulin may also down-regulate cyclin D1 in esophageal cancer cells and lead to G1/S arrest, and that these effects are through inactivation of CDK4/6 and dephosphorylation (activation) of Rb. 3. To determine the effects of cornulin on PI3K/Akt signaling pathway Rationale: The phosphatidylinositol-3-kinase (PI3K) and Akt (Protein Kinase B) signaling pathway is frequently activated in human cancers. The pathway regulates a wide spectrum of cellular functions including proliferation and survival, and is known to induce many downstream targets including cyclin D1 [7]. We would like to explore if there is a link between the PI3K/Akt signaling pathway and the down-regulation of cyclin D1 by cornulin. References: 1. Hanahan D & Weinberg RA. (2000). The hallmarks of cancer. Cell, 100:57-70. 2. Xu ZX, et al. (2000). Novel human esophagus-specific gene c1orf10: cDNA cloning, gene structure, and frequent loss of expression in esophageal cancer. Genomics, 69:322-30. 3. Contzler R, et al. Cornulin, a new member of the “fused gene” family, is expressed during epidermal differentiation. (2005). J Invest Dermatol, 124: 990-7. 4. Li J, et al. (2005). Allelic imbalance of chromosome 1q in esophageal squamous cell carcinomas from China: a novel region of allelic loss and significant association with differentiation. Cancer Lett, 220(2):221-30. 5. Yagui-Beltran A, et al. (2001). The human oesophageal squamous epithelium exhibits a novel type of heat shock protein response. Eur J Biochem, 268:5243-55. 6. Imai FL, et al. (2005). Chromosome 1 open reading frame 10 (C1orf10) gene is frequently down-regulated and inhibits cell proliferation in oral squamous cell carcinomaInt. J Biochem Cell Biol 37:1641-55. 7. Brazil DP & Hemmings BA (2001). Ten years of protein kinase B signalling: a hard Akt to follow. Trends Biochem Sci, 26:657-664.

Project Title:	Targeting NFKB pathway suppresses human esophageal cancer progression
Investigator(s):	Cheung A
Department:	Anatomy
Source(s) of Funding:	Small Project Funding
Start Date:	01/2009
Completion Date:	12/2010

Abstract:

Background: The nuclear factor-κB (NFκB) transcription factor family is composed of p50, p52, RelA/p65, c-rel and Rel B. The homo- and heterodimers are sequestered in the cytoplasm as an inactive form by inhibitor of κB (IκB) (1). Upon stimulation, the IκB kinase (IKK) complex phosphorylates the IκB, which then releases NFκB and allows its phosphorylation, nuclear translocation, binding and subsequent activation of target genes involved in the regulation of cell proliferation, survival, angiogenesis and metastasis (2). Constitutively activated NFκB has been identified in human cancer cell lines as well as tumor tissues derived from patients, but rarely in normal cells (3), which implies that it may be an ideal target for therapeutic intervention. In some types of human cancer, there is strong evidence of NFκB being involved in cancer progression, thus making NFκB and its downstream signals promising targets for therapeutic intervention (4, 5). Key issues: Esophageal cancer usually carries a poor prognosis due to late diagnosis, distant metastasis and the resistance of the tumor to radiotherapy and chemotherapy. Development of new therapeutic options is of paramount importance to improve patient survival. Esophageal squamous cell carcinoma (ESCC) is the predominant form of esophageal cancer in this part of the world. We have previously established that NFκB plays a role in protecting ESCC cells from TNF- induced apoptosis (6), but its role in esophageal cancer growth and progression (i.e. invasion and metastasis) is still not fully understood. Although there are some papers reporting that inhibiton of NFκB can increase the drug sensitivity of esophageal cancer cells in vitro (7, 8), there is very little clinical or in vivo experimental data on the effects on tumor growth and metastasis. Thus, the feasibility of targeting NFκB as a potential treatment for esophageal cancer remains unexplored. Purpose: The aim of this study is to investigate the role of NFκB signaling pathway in human esophageal cancer progression, and to determine whether inhibition of the NFκB signaling pathway has anti-cancer effects in vitro and in vivo. Objectives: 1． To study the expression of NFκB in esophageal squamous cell carcinoma Rationale: Aberrant NFκB expression (i.e. constitutive expression or persistent nuclear localization) has been detected in many types of human cancer cell lines as well as tumor tissues including esophageal adenocarcinoma, but has not been described in ESCC. We HYPOTHESIZE that the NFκB pathway, as a crucial signaling pathway involved in human cancer, may also be activated in ESCC, and we will use established cell lines, as well as ESCC tissue samples, to confirm this point. 2． To study the effects of NFκB inhibitors on human esophageal cancer cell proliferation, drug resistance, migration and invasion in vitro Rationale: From the published results on some other cancer types, the strong evidence of NFκB being involved in cancer progression led us to HYPOTHESIZE that blockade of this pathway may inhibit the esophageal cancer progression. Bay11 and sulfasalazine are two well-known and commonly used NFκB inhibitors. Their significant effects on glioblastoma and renal cell carcinoma in vitro and in vivo have been reported recently (4, 5). We postulate that these two inhibitors, Bay11 and sulfasalazine, may suppress the proliferative, invasive and migratory potentials of ESCC cell, and increase their sensitivity to conventional chemotherapeutic drugs in vitro. 3．To study the effects of NFκB inhibition on growth and metastasis of human esophageal cancer cells in vivo Rationale: Tumor metastasis involves a sequence of events which includes escape of cancer cells from the primary tumor, intravasation of the tumor vasculature, followed by extravasation and colonization of secondary sites. The involvement of NFκB in regulation of tumor metastasis in other cancer types led us to HYPOTHESIZE that inhibition of NFκB may suppress the metastasis of esophageal cancer cells to other organs, such as lungs. We therefore propose to perform in vivo animal experiments to evaluate the therapeutic potential of NFκB inhibitors in human esophageal cancer treatment. The use of spontaneous and experimental metastasis assays is particularly relevant for esophageal cancer since tumor metastasis is one of the main reasons contributing to low survival rate of esophageal cancer patients.

Project Title:	Synergistic effect and molecular mechanisms of green tea (EGCG) and vitamin C in the prevention of esophageal cancer
Investigator(s):	Cheung A, Tsao GSW
Department:	Anatomy
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	03/2010

Abstract:

KEY ISSUE: Esophageal squamous cell carcinoma (ESCC) is the most common form of esophageal cancer throughout the Asia-Pacific region including mainland China and Hong Kong. Despite advances in treatment modalities, the mortality rate of ESCC remains exceptionally high mainly due to late diagnosis. Carcinogenesis is a multi-stage process that transforms normal epithelial cells to premalignant lesions and on to invasive carcinoma. Increasing attention is focused on the use of non-toxic chemopreventive agents to block or delay the process. In this regard, naturally occurring antioxidants present in the diet and beverages are ideal candidates. PURPOSE AND PROLBEMS BEING ADDRESSED: Green tea is one of the most popular beverages consumed around the world. (-)-Epigallocatechin-3-gallate (EGCG) is the major and most effective component of green tea in preventing and inhibiting experimental carcinogenesis. With advantages such as cancer-specific effects [1], regulation of multiple signaling pathways [2], non-toxicity even over a relatively long treatment period [3], EGCG seems to be an ideal chemopreventive agent. With regard to human esophageal cancer, although a number of population-based studies have reported on the protective effects of green tea consumption [4,5], there are very few laboratory studies that provide experimental findings on the effects and molecular mechanisms of green tea in esophageal cancer. Epidemiological studies indicate that esophageal cancer is associated with exposure to nitrosamine compounds, tobacco smoking and low intakes of vegetables and fruits and. Interestingly, according to the National Health and Nutrition Examination Survey III (1988-1991) in the U.S., smokers have significantly lower intake of fruits and vegetables per day, and therefore lower levels of serum vitamin C and -carotene compared to non-smokers. Vitamin C (ascorbic acid), present in high abundance in many fruits and vegetables, has been shown to be inversely correlated with the development of esophageal cancer [6,7]. However, up to now there is no experimental data on which agent(s) can inhibit smoking-induced esophageal carcinoma.. Although EGCG and vitamin C seem to be good chemopreventive agents for human cancer, they both have drawbacks: EGCG is unstable under physiologic conditions and has poor bioavailability [8], whereas high dose vitamin C reportedly has potentially harmful side-effects including kidney stones, iron overload, and elevated urinary uric acid. However, recent studies showed that vitamin C can extend the half-life and enhance the anti-bacterial effects of EGCG through inhibition of its oxidation [9,10], thus resolving the only potential shortcoming of EGCG as an anti-cancer agent. On the other hand, physiological levels of EGCG can increase the cellular lipid antioxidant activity of vitamin C [11]. These findings lead us to hypothesize that, EGCG and vitamin C may be an ideal combination in the prevention and treatment of human cancer due to their synergistic effects. The aim of this project is to determine the synergistic effects of these two agents in preventing esophageal cancer, and to study the mechanisms involved. THE SPECIFIC OBJECTIVES ARE: 1. To study the anti-cancer effects of EGCG/green tea and vitamin C on esophageal cancer cells. Rationale: Unlimited replicative potential, evasion of apoptosis, angiogenesis, tissue invasion and metastasis are hallmarks of cancer [12]. The suppressive effects of EGCG, vitamin C, or their combination on these processes can be investigated in vitro using esophageal cancer cell lines. We aim to prove that combination of EGCG and vitamin C has synergistic effect in suppressing esophageal cancer growth and progression. Effective chemopreventive agents should be able to inhibit the growth and progression (invasion into surrounding tissue and metastasis) of cancer cells in vivo, we have also designed in vivo experiments to support the in vitro findings. Notably, green tea extract (instead of EGCG), with or without the addition of vitamin C, will be used. This is based on the notion that although pure agents rather than complex mixtures offer a rational choice for deciphering the mechanisms of action in the in vitro system, green tea extract or infusion is more relevant to real life situation as it is widely consumed as beverage. 2. To study the chemopreventive effects of EGCG and vitamin C on malignant transformation of esophageal epithelial cells. Rationale: Loss of p16, p53 mutations, cyclin D1 amplification and activation of telomerase are amongst the most common genetic alterations associated with esophageal carcinogenesis. We have recently established an immortalized esophageal epithelial cell line NE2-hTERT through overexpression of human telomerase (hTERT) which helped extend the lifespan of the cells. Coupled with spontaneous loss of p16, the NE2-hTERT cells acquired unlimited replication potential and became immortalized, which is an early and indispensable step towards cancer initiation. It is well documented that the tobacco-specific carcinogen nitrosamine (NNN) can specifically induce esophageal cancer in animal models [13]. We found that both exposure to cigarette smoke condensate (CSC) and overexpression of cyclin D1 in immortalized NE2-hTERT could malignantly transform the cells, as evidenced by anchorage-independent growth. Since EGCG has been shown to suppress cyclin D1 in intestinal epithelial cells [14], this in vitro cell line model system is an ideal tool for evaluating the effects of EGCG and vitamin C on suppressing malignant transformation of normal esophageal epithelial cells at the early stage of esophageal carcinogenesis. 3. To study the mechanisms involved in the anti-cancer effects of EGCG and vitamin C in esophageal cancer. Rationale: Cyclin D1 amplification is one of the most common genetic alterations in esophageal cancer. To our knowledge, cyclin D1 transgenic mice is the only successful transgenic mouse model for initiation of esophageal cancer. It has been reported that EGCG regulates expression of cyclin D1 in a variety of other cancers [15,2]. Whether the same holds for esophageal cancer has not been elucidated. Furthermore, cyclin D1 is a downstream target of PI3K/Akt/NFKB signaling pathway --- one of the most frequently activated pathway in human cancer, and plays a crucial role in regulating the G1/S phase checkpoint. Whether EGCG induces G1/S cell cycle arrest through suppression of PI3K/Akt/NFKB signaling pathway and regulation of cyclinD1-CDK4/6-Rb axis, and whether vitamin C can potentiate these effects, will be analyzed in this study.

List of Research Outputs

Cheung P.P.Y., Deng W., Man C.W.Y., Tse W.W., Srivastava G., Law S.Y.K., Tsao G.S.W. and Cheung A., Genetic alterations in a telomerase-immortalized human esophageal epithelial cell line: Implications for carcinogenesis, Cancer Letters. 2010, 293: 41-51.

Li B., Li Y.Y., Tsao G.S.W. and Cheung A., Targeting NF-kB signaling pathway suppresses tumor growth, angiogenesis, and metastasis of human esophageal cancer, Molecular Cancer Therapeutics. 2009, 8(9): 2635-2644.

Tsang C.M., Lau P.W.E., Di K., Cheung P.P.Y., Hau P.M., Ching Y.P., Wong Y.C., Cheung A., Wan T.S.K., Tong Y., Tsao G.S.W. and Feng Y., Berberine inhibits Rho GTPases and cell migration at low doses but induces G2 arrest and apoptosis at high doses in human cancer cells, International Journal of Molecular Medicine. 2009, 24: 131-138.

Tsang C.M., Zhang G., Seto E., Takada K., Deng W., Yip Y.L., Man C.W.Y., Hau P.M., Chen H., Cao Y., Lo K.W., Middeldorp J.M., Cheung A. and Tsao G.S.W., Epstein-Barr virus infection in immortalized nasopharyngeal epithelial cells: Regulation of infection and phenotypic characterization. , International Journal of Cancer. 2010, 127: 1570-1583.

Tsao G.S.W., Tsang C.M., Zhang G., Deng W., Hau P.M., Man C.W.Y., Kenzo T., Chen H., Yip Y.L., Lo K.W., Cao Y. and Cheung A., Epstein-Barr virus infection confer stress-resistant property in immortalized nasopharyngeal epithelial cells., Proceedings of American Association of Cancer Research. 2010.

Yip Y.L., Tsang C.M., Jin Y., Deng W., Man C.W.Y., Cheung P.P.Y., Chen H., Cheung A. and Tsao G.S.W., The Epstein-Barr virus-encoded LMP1 extended the life span and immortalized nasopharyngeal epithelial cells., Hong Kong International Cancer Congress . 2009.

Researcher : Cheung AKH

List of Research Outputs

Yeung C.M., Lo A.C.Y., Cheung A.K.H., Chung S.S.M., Wong D.S.H. and Chung S.K., More severe type 2 diabetes-associated ischemic stroke injury is alleviated in aldose reductase-deficient mice, Journal of Neuroscience Research. 2010, 88: 2026-2034.

Researcher : Cheung ALM

Project Title:	Centromeric instability in human cells undergoing immortalization: implication for progression of chromosomal instability in carcinogenesis
Investigator(s):	Cheung A, Tsao GSW, Guan XY, Deng W
Department:	Anatomy
Source(s) of Funding:	General Research Fund (GRF)
Start Date:	01/2007
Completion Date:	12/2009

Abstract:

Project Title:	Cornulin as a novel candidate tumor suppressor gene in esophageal cancer
Investigator(s):	Cheung A, Tsao GSW
Department:	Anatomy
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	01/2008
Completion Date:	06/2010

Abstract:

Project Title:	Targeting NFKB pathway suppresses human esophageal cancer progression
Investigator(s):	Cheung A
Department:	Anatomy
Source(s) of Funding:	Small Project Funding
Start Date:	01/2009
Completion Date:	12/2010

Abstract:

Project Title:	Synergistic effect and molecular mechanisms of green tea (EGCG) and vitamin C in the prevention of esophageal cancer
Investigator(s):	Cheung A, Tsao GSW
Department:	Anatomy
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	03/2010

Abstract:

List of Research Outputs

Researcher : Cheung MPL

List of Research Outputs

Li R.H.W., Chiu C.N., Cheung M.P.L., Yeung W.S.B. and O W.S., Effect of leptin on motility, capacitation and acrosome reaction of human spermatozoa, International Journal of Andrology. 2009, 32: 687-694.

O W.S., Li L., Cheung M.P.L. and Tang F., The role of adrenomedullin in embryo implantation in the rat, The First State Key Laboratory of Reproductive Biology on Frontiers in Perrimplantation Biology. 2010, 60.

Wong C.L., Wong Y.Y., Ho W.K., Poon H.K., Cheung M.P.L., O W.S. and Chow P.H., Growth-differentiation factor-8 (GDF-8) in the uterus: its identification and functional significance in the golden hamster, Reproductive Biology and Endocrinology. 2009, 7: 134-147.

Zhao W., O W.S., Fung Y.S. and Cheung M.P.L., Analysis of mitochondria by capillary electrophoresis: Cardiolipin levels decrease in response to carbonyl cyanide 4-(trifluoromethoxy) phenylhydrazone, European Journal of Lipid Science and Technology. 2010, 112: 1058-1066.

Researcher : Cheung PPY

List of Research Outputs

Cheung P.P.Y., Deng W., Man C.W.Y., Tse W.W., Srivastava G., Law S.Y.K., Tsao G.S.W. and Cheung A., Genetic alterations in a telomerase-immortalized human esophageal epithelial cell line: Implications for carcinogenesis, Cancer Letters. 2010, 293: 41-51.

Tsang C.M., Lau P.W.E., Di K., Cheung P.P.Y., Hau P.M., Ching Y.P., Wong Y.C., Cheung A., Wan T.S.K., Tong Y., Tsao G.S.W. and Feng Y., Berberine inhibits Rho GTPases and cell migration at low doses but induces G2 arrest and apoptosis at high doses in human cancer cells, International Journal of Molecular Medicine. 2009, 24: 131-138.

Yip Y.L., Tsang C.M., Jin Y., Deng W., Man C.W.Y., Cheung P.P.Y., Chen H., Cheung A. and Tsao G.S.W., The Epstein-Barr virus-encoded LMP1 extended the life span and immortalized nasopharyngeal epithelial cells., Hong Kong International Cancer Congress . 2009.

Researcher : Cheung WH

List of Research Outputs

Ellis-Behnke R.G., Liang Y., Cheung W.H. and Tay D.K.C., Controlling The Growth And Differentiation Of Cells With Physical Interaction, Nanobiotech 2009.

Ellis-Behnke R.G., Cheung W.H., Liang Y. and Liang Y., Nanomedicine and nanotechnology applied to neurosciences, 4th International Multidisciplinary Congress on Intensive and Critical Care Medicine. 2009.

Ellis-Behnke R.G., Cheung W.H., Liang Y. and Tay D.K.C., Nanoscale Image Contrast Agents To Enhance The Visualization Of Regenerating Cns Axons, Presidential Symposium on Nanotechnology at the 51st Meeting of the American Society for Therapeutic Radiology and Oncology (ASTRO). 2009.

Ellis-Behnke R.G., Liang Y., Cheung W.H., So K.F., Wu W. and Tay D.K.C., Redefining tissue engineering for nanomedicine: Visualizing the progress of regenerating axons in the mammalian visual system after complete transection and treatment with self-assembling nanomaterial, 6th Annual World Congress for Brain Mapping and Image Guided Therapy, Harvard Medical School, Boston MA. 2009.

Ellis-Behnke R.G., Liang Y., Cheung W.H. and Tay D.K.C., Using nanotechnology to control the elongation, differentiation and proliferation of cells, 16th Annual Optic Nerve Rescue and Restoration Think Tank. 2009.

Researcher : Cheung YT

List of Research Outputs

Chang R.C.C., Zhang Q., Hung H.L., Cheung Y.T., Ho Y.S., Lai S.W. and Wuwongse S., Pathogenesis of Alzheimer's Disease, 5th International Symposium on Healthy Aging. 2010, Page 19.

Cheung Y.T., Zhang N.Q., Hung C.H.L., Lai S.W., Yu M.S. and Chang R.C.C., Autophagy may protect neurons from low molecular weight beta-amyloid peptide-induced apoptosis, 5th International Symposium on Healthy Aging. 2010, Page 58.

Cheung Y.T., Zhang Q., Hung H.L., Lai S.W., Yu M.S., So K.F. and Chang R.C.C., Investigating the temporal transition of autophagy and apoptosis in neurons stressed by low molecular weight beta-amyloid peptide toxicity, 11th International Geneva/Springfield Symposium on Advances in Alzheimer Therapy, March 24-27, 2010 Geneva. 2010, 42.

Cheung Y.T., Investigation of neuronal apoptosis and autophagy in beta-amyloid peptide toxicity. 2009, 148 pages.

Cheung Y.T., Lau K.W. and Chang R.C.C., What do we need to concern in using cell line for neurotoxicology research, differentiation or disturbance of intracellular signaling?, NeuroToxicology. 2009, 31: 164-166.

Hung C.H.L., Cheung Y.T., Ho Y.S. and Chang R.C.C., Intracellular organelle collapse triggered by low molecular weight b-amyloid peptides, 5th International Symposium on Healthy Aging. 2010, Page 61.

Zhang N.Q., Cheung Y.T., Ho Y.S. and Chang R.C.C., Impact of low molecular weight Ab on autophagosomes and proteasomes via collapse of the endoplasmic reticulum, 5th International Symposium on Healthy Aging. 2010, Page 61.

Researcher : Cheung YT

List of Research Outputs

Chang R.C.C., Zhang Q., Hung H.L., Cheung Y.T., Ho Y.S., Lai S.W. and Wuwongse S., Pathogenesis of Alzheimer's Disease, 5th International Symposium on Healthy Aging. 2010, Page 19.

Cheung Y.T., Investigation of neuronal apoptosis and autophagy in beta-amyloid peptide toxicity. 2009, 148 pages.

Researcher : Ching YP

Project Title:	Roles of p21-activated protein kinase (Pak) 1 in the pathogenesis of liver cancer
Investigator(s):	Ching YP, Ng IOL, Jin D, Yau TO
Department:	Pathology
Source(s) of Funding:	General Research Fund (GRF)
Start Date:	01/2006

Abstract:

(1) To characterize the mechanisms leading to Pak1 overexpression in human HCC; (2) to delineate the roles of Pak1 in hepatocarcinogenesis: (i) Phosphorylation of possible downstream targets of Pak1 in human HCCs. (ii) characterization of the tumorigenic activity of Pak1 in HCC cells. (iii) characterization of the anti-apoptotic activity of Pak1 in HCC cells. (3) to investigate the role of Pak1 in cancer metastasis: >(i) regulation of cell motility and cell adhesion by Pak1 in HCC cells. (ii) HGF/Rac1/Cdc42/Pak1 signaling in HCC metastasis. (iii) HGF/Pak1 mediated angiogenic activity. (iii) HGF/Pak1 mediated angiogenic activity.

Project Title:	Molecular neurobiology: Regulation of p21-activated protein kinase 5 in neurodegenerative disease
Investigator(s):	Ching YP
Department:	Anatomy
Source(s) of Funding:	Matching Fund for NSFC Young Researcher Award
Start Date:	01/2007
Completion Date:	12/2009

Abstract:

To study molecular neurobiology: regulation of p21-activated protein kinase 5 in neurodegenerative disease.

Project Title:	The roles of CDK5 activator binding protein, LZAP, in the pathogenesis of neurodegenerative disease
Investigator(s):	Ching YP
Department:	Anatomy
Source(s) of Funding:	Travel Grants for NSFC/RGC JRS
Start Date:	12/2007

Abstract:

Travel grants for NSFC/RGC JRS.

Project Title:	Functional characterization of a putative tumour suppressor, AMP-activated protein kinase, in liver cancer
Investigator(s):	Ching YP, Jin D, Ng IOL
Department:	Pathology
Source(s) of Funding:	General Research Fund (GRF)
Start Date:	01/2008

Abstract:

(1) Investigation of the dysregulation of AMPK in HCC (12 months), i) Expression of AMPK subunits and its regulators in HCC-(LKB1 and AMPK, ii) Confirmation of the dysregulation of AMPK signaling in HCC; (2) investigation of the genetic basis of loss of AMPK 2 exression in human HCC and HCC cells (9 months), i) Epigenetic silencing, ii) Genetic alterations (only LOH); (3) tumor suppressor activity of AMPKa2 in HCC (18 months), i) Characterization of the tumor suppressor activity of AMPK in HCC cells; (4) investigation of AMPKa2 cell signalling and tumor suppression(18 months), i) Negative regulation of mTOR by AMPK in HCC, ii) AMPK-mediated upregulation of p53 in HCC.

Project Title:	Functional characterisation of a novel p14ARF regulating protein, LZAP, in HCC
Investigator(s):	Ching YP
Department:	Anatomy
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	04/2008
Completion Date:	03/2010

Abstract:

Objective: HCC is the second most common fatal cancer in Hong Kong. Different risk factors, such as hepatitis B and C virus infection, cirrhosis, and dietary aflatoxin, are well established in HCC. However, details of the genetic changes in pathogenesis and tumor progression are poorly defined in HCC. In our previous study, we have identified a novel cyclin dependent protein kinase 5 (Cdk5) activator interacting protein, named C53 (now called LZAP, LXXLL/leucine-zipper-containing ARF binding protein), which is ubiquitously expressed in human tissues. Evidence has shown that LZAP regulates apoptosis induced by genotoxic stress and overexpression of LZAP can promote cell proliferation. More recently, LZAP is found to interact with a tumor suppressor, p14ARF, which is a key regulator of cell senescence. In our preliminary study using real-time quantitative RT-PCR, we found that over 69% (33/48) of human HCC samples had significantly higher expression (>2 folds) of LZAP transcripts as compared to their corresponding nontumorous livers. The overexpression of LZAP was statistically correlated with clinicopathological features, i.e. poorer cellular differentiation and liver invasion. Interestingly, our data also indicated that knockdown of LZAP in HCC cells resulted in an upregulation of p14ARF. Thus, we hypothesize that overexpression of LZAP may contribute to the development of HCC by inhibition of cellular senescence. Aims: In order to better understand the roles of LZAP in the pathogenesis of HCC, we aim to: 1.Characterize the overexpression of LZAP protein in human HCC 2.Investigate the tumorigenic roles of LZAP in human HCC 3.Investigate the roles of LZAP/ARF in HCC Our study will characterize how dysregulation of LZAP can lead to the development of HCC and will provide novel insight for new molecular drug targets and for new therapeutic treatment.

Project Title:	The roles of CDK5 activator binding protein, LZAP, in the pathogenesis of neurodegenerative disease
Investigator(s):	Ching YP, Jin D
Department:	Anatomy
Source(s) of Funding:	NSFC/RGC Joint Research Scheme
Start Date:	01/2009

Abstract:

(1) Characterisation of the roles of LZAP in Nclk signaling i) Identification of the Cdk5 phosphorylation sites on LZAP ii) Roles of LZAP in Nclk-mediated neuronal differentiation; (2) Characterisation of the role of LZAP in NF-kappaB activity in neurons; (3) Characterisation of the role of LZAP in neuronal apoptosis i) regulation of neuronal apoptosis by LZAP ii) LZAP and p53 signaling iii) LZAP and JNK signaling; (4) Defining the roles of LZAP in the pathogenesis of neurodegenerative disease.

Project Title:	Characterisation of the role of p21-activated protein kinase 4 in liver cancer
Investigator(s):	Ching YP
Department:	Anatomy
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	04/2009

Abstract:

Liver cancer (hepatocellular carcinoma, HCC) is one of the most common cancers worldwide. Different risk factors, such as hepatitis B and C virus infection, cirrhosis, and dietary aflatoxin, are well established in HCC. However, details of the genetic changes in pathogenesis and tumor progression, particularly in metastasis, are poorly defined in HCC. P21-activated protein kinase (PAK) is the main downstream effector of small Rho GTPases, Rac1 and Cdc42, which regulate diverse cellular processes, including cell migration, polarization, gene transcription and cell survival. Recently, we have shown that PAK1 was overexpressed in HCC and is involved in HCC metastasis. However, little information is available for the roles and regulation of other Pak’s family member in carcinogenesis. Here we obtained preliminary data suggesting that another PAK’s family member, PAK4, was overexpressed in HCC. Using quantitative real-time PCR, we have observed that over 60% of human HCC samples (40/63 cases) have significantly higher expression (>2 folds) of PAK4 transcripts as compared to their corresponding nontumourous livers. In addition, the overexpression of PAK4 significantly correlates with clinicopathological features, including venous invasion, liver invasion and poorer cellular differentiation. The overexpression of PAK4 at protein level in HCCs was also confirmed by Western blotting. These data suggest that PAK4 may play a role in the formation of HCC in general and in cancer metastasis in particular. In this proposal, we will further investigate how the overexpression of PAK4 leads to hepatocarcinogenesis. The potential influence of overexpression of PAK4 on apoptosis, tumorigenicity and metastatic potential of HCC cells will be evaluated. Finally, we will try to elucidate the molecular mechanisms by which PAK4 promotes cancer metastasis. Findings derived from our work will provide novel insight into the development and metastasis of liver cancer and might reveal novel strategies for intervention.

Project Title:	Hepatitis B virus promotes hepatocarcinogenesis by activation of Pak1
Investigator(s):	Ching YP, Jin D
Department:	Anatomy
Source(s) of Funding:	Research Fund for the Control of Infectious Diseases - Full Grants
Start Date:	01/2010

Abstract:

To investigate the mechanism by which HBX activates Pak1; to define the role of Pak1 in HBV replication; to examine if inhibition of Pak1 activity prevents HBV-induced HCC.

Project Title:	Functional characterisation of a novel centrosomal protein, TAX1BP2, in liver cancer development
Investigator(s):	Ching YP
Department:	Anatomy
Source(s) of Funding:	General Research Fund (GRF)
Start Date:	01/2010

Abstract:

1) Defining the loss of TAX1BP2 expression in human HCC 1.1 Clinicopathological correlation analysis of TAX1BP2 in HCC; 2) Defining the tumor suppressor activity of TAX1BP2 2.1 Confirmation of the tumor suppressor activity of TAX1BP2; 3) Investigating the roles of TAX1BP2 in cell cycle control 3.1 Characterisation of TAX1BP2 phosphorylation in cell cycle progression 3.2 Characterisation of TAX1BP2 phosphorylation in centrosome duplication.

Project Title:	Characterisation of the roles of LKB1 in liver cancer formation
Investigator(s):	Ching YP
Department:	Anatomy
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	04/2010

Abstract:

Liver cancer (hepatocellular carcinoma, HCC) is one of the most common cancers worldwide. Different risk factors, such as hepatitis B and C virus infection, cirrhosis, and dietary aflatoxin, are well established in HCC. However, details of the genetic changes in pathogenesis and tumor progression, particularly in metastasis, are poorly defined in HCC. LKB1, which is a serine/theonine kinase, regulates diverse cellular processes, including cell migration, polarization, energy metabolism and cell survival. Mutations in the LKB1 gene are found in Peutz-Jeghers syndrome (PJS) patients, who have a much higher chance to develop cancers of epithelial tissue origin. Although LKB1 has been well documented to suppress cancer formation, the detail molecular mechanism by which LKB1 inhibits carcinogenesis is unclear. Using quantitative real-time RT-PCR, we have observed that over 37% of human HCC samples (12/32 cases) have significantly lower expression (>2 folds) of LKB1 transcripts as compared to their corresponding nontumourous livers. In addition, the underexpression of LKB1 significantly correlates with poorer disease free survival rate, suggesting a poorer prognosis of patient. Also, we have obtained preliminary evidence suggesting that LKB1 may phosphorylate beta-catenin at serine residue at position 45, which is important for the breakdown of the protein. Thus, we hypothesize that LKB1 is an important regulator for beta-catenin and loss of LKB1 may promote the accumulation of beta-catenin in HCC cells, leading to hepatocarcinogenesis. In this proposal, we will investigate how underexpression of LKB1 induces HCC formation. More importantly, we will examine the role of LKB1 in regulating beta-catenin activity. Thus our work will derive novel insight into the role of LKB1 in the development of liver cancer and might reveal novel strategies for intervention.

Project Title:	LKB1-AMPK Meeting Underexpression of LKB1 in hepatcellular carcinoma
Investigator(s):	Ching YP
Department:	Anatomy
Source(s) of Funding:	URC/CRCG - Conference Grants for Teaching Staff
Start Date:	06/2010
Completion Date:	06/2010

Abstract:

N/A

List of Research Outputs

Ching Y.P., Autophagy, 2nd HKU - PASTEUR CELL BIOLOGY COURSE organised by Pasteur Institute. 2010.

Huen M.S.Y., Huang J., Leung J.W.C., Sy S.M.H., Leung K.M., Ching Y.P., Tsao G.S.W. and Chen J., Regulation of Chromatin Architecture by the PWWP Domain-Containing DNA Damage-Responsive Factor EXPAND1/MUM1, MOLECULAR CELL. 2010, 37(6): 854-864.

Lau W.M., Yau S.Y., Lee T.M.C., Ching Y.P., Tang S.W. and So K.F., Corticosterone suppresses dendritic maturation of immature neurons in hippocampus, which is counteracted by antidepressant treatment, Neuroscience Bulletin. 2009, 25(1): 450.

Lau W.M., Yau S.Y., Lee T.M.C., Ching Y.P., Tang S.W. and So K.F., Effect of corticosterone and paroxetine on masculline mating behavior: Possible involvement of neurogenesis, Pan Pacific Symposium on Stem Cells Research, April 16-19, 2010, Taiwan. 2010, 77.

Lau W.M., Yau S.Y., Lee T.M.C., Ching Y.P., Tang S.W. and So K.F., Possible involvement of neurogenesis in male rat mating behavior, Cell Transplantation. 2010, 19(3): 347.

Lee C.W. and Ching Y.P., Identification of downstream targets of LKB1, The 32th annual meeting of the molecular biology society of Japan. 2009.

Lee C.W. and Ching Y.P., The role and Regulation of SirT1 throungh the LKB1-AMPK Pathway in Hepatocellular carcinoma, 16th Hong Kong International Cancer Congress. 2009.

Lee C.W. and Ching Y.P., Underexpression of LKB1 in hepatcellular carcinoma, The LKB1-AMPK pathway from Basic science to clinical applications . 2010.

Leung T.H.Y., Yam J.W.P., Chan L.K., Ching Y.P. and Ng I.O.L., DLC2 (Deleted in liver cancer 2) suppresses cell growth via regulation of Raf-1-ERK1/2-p70S6K signaling pathway. (accepted), Liver International. 2010.

Luk S.U., Yap W.N., Chiu Y.T., Lee D.T.W., Ma S.K.Y., Lee K.W., Vasireddy R.S., Wong Y.C., Ching Y.P., Nelson C.O.L.L.E.E.N., Yap Y.L. and Ling M.T., Gamma-tocotrienol as an effective agent in targeting prostate cancer stem cell-like population, International Journal of Cancer. 2010.

Mak G.W.Y., Ng I.O.L. and Ching Y.P., Characterization of CDK5RAP3 in hepatocellular carcinoma, AACR 101st Annual Meeting. 2010.

Mak G.W.Y., Ng I.O.L. and Ching Y.P., Functional characterization of CDK5RAP3 in Human Hepatocellular Carcinoma Cells, 16th Hong Kong International Cancer Congress. 2009.

Ng M.H., Siu K.L., Ching Y.P. and Jin D., MIP-T3 is a novel inhibitor in TBK1/IRF3-dependent antiviral response, The American Society for Virology 28th Annual Meeting, University of British Columbia, Vancouver, BC, Canada. 2009.

Poon H.F., Xu H. and Ching Y.P., Characterization of the Roles of PAK5 in Neuronal Development , In: Prague, Czech Republic, 34th FEBS Congress: Life's Molecular Interactions. 2009.

Tsang C.M., Lau P.W.E., Di K., Cheung P.P.Y., Hau P.M., Ching Y.P., Wong Y.C., Cheung A., Wan T.S.K., Tong Y., Tsao G.S.W. and Feng Y., Berberine inhibits Rho GTPases and cell migration at low doses but induces G2 arrest and apoptosis at high doses in human cancer cells, International Journal of Molecular Medicine. 2009, 24: 131-138.

Yau S.Y., Lau W.M., Tong J., Ching Y.P., Lee T.M.C. and So K.F., Hippocampal cell proliferation and dendritic enrichment is essential for beneficial effects of exercise on stressed animal model, Hellenic Society for Neuroscience, 23rd Annual Meeting, September 13-14, 2009, Greece.. 2009, 78-79.

Yau S.Y., Lau W.M., Tong J., Wong R., Ching Y.P., Qiu G., Tang S.W., Lee T.M.C. and So K.F., Hippocampal cytogenesis and dendritic plasticity support running-enhanced memory and depression behavior, Proceedings of the International Anatomical Sciences and Cell Biology Conference, May 26-29, 2010. 37.

Yau S.Y., Lau W.M., Tong J., Wong R., Ching Y.P., Qiu G., Tang S.W., Lee T.M.C. and So K.F., Hippocampal cytogenesis and dendritic plasticity support running-enhanced memory and depression behaviour in stressed rat, The 4th Beijing International Forum on Rehabilitation, Oct. 28-30, 2009. 6-7.

Yau S.Y., Lau W.M., Tong J.B., Ching Y.P., Qiu G., Lee T.M.C. and So K.F., Hippocampal neurogenesis and dentritic enrichment are involved in neuroprotective of physical exercise on stress., Neuroscience Bulletin. . 2009, 25 Supp 1: 379-380.

Researcher : Chiu J

List of Research Outputs

Chiu K., Zhou Y., Yeung S.C., Lok C.K.M., Chan O.O.C., Chang R.C.C., So K.F. and Chiu J., Up-regulation of crystallins is involved in the neuroprotective effect of wolfberry on survival of retinal ganglion cells in rat ocular hypertension model, Journal of Cellular Biochemistry. 2010, 110: 311-320.

Researcher : Chiu K

Project Title:	Significance of amyloid precursor protein processing and amyloid beta deposition in the retinal neurodegeneration: do ER-stress signaling or mitochondrial stress signaling involved?
Investigator(s):	Chiu K, So KF, Chang RCC
Department:	Anatomy
Source(s) of Funding:	Small Project Funding
Start Date:	09/2009

Abstract:

The purpose of this proposed project is to investigate the involvement of ER-stress signaling or mitochondrial stress signaling in the amyloid [beta] deposition induced loss of retinal neuron loss in the APP-Swedish mutant transgenic (Tg) mice. And investigate whether biological targeting of signaling events can be applied for future pharmacological intervention. Alzheimer’s disease (AD) is the most common form of dementia among older people. An estimated 26.6 million people worldwide had Alzheimer's in 2006; this number may quadruple by 2050 (Brookmeyer et al, 2007). AD is an age related progressive neurodegenerative disease and the histopathology of AD is characterized by accumulation of senile plaques (extracellular deposits of amyloid-[beta] (A[beta]) peptides), neurofibrillary tangles (intracellular hyperphosphorylated tau proteins) and massive loss of neurons and synapses in the cerebral cortex and certain subcortical regions. Beside the deficits in cognition and behavior, vision abnormalities are common among AD patients. Degeneration and loss of retinal ganglion cells (RGCs) and their axons, reduction of the retinal nerve fiber layer (RNFL) thickness, and increased optic cupping have also been observed in AD patients (Hinton et al, 1986; Blanks et al, 1989, 1996 a & b; Sadun et al, 1990). Recent studies investigated retinal changes in AD mouse models (APP/PS1 transgenic mouse line) showed alteration in amyloid precursor protein (APP) processing and A[beta] accumulation in the neurons of retinal ganglion cell layer (RGCL) and inner nuclear layer (INL). In addition, apoptotic cells were also detected in the RGCL (Ning et al, 2008; Dutescu et al, 2009). Thus, understanding of the molecular mechanisms of inner retinal neuronal loss causing by accumulation of A[beta] peptide would let us know more about the pathogenesis of AD. Endoplasmic reticulum (ER) stress has been suggested for the induction of neurodegeneration in AD (Katayama et al, 2004). Our recent publication has demonstrated that in human AD hippocampal sections, calreticulin was markedly decreased when compared to the age-matched control brain sections. Similar phenomena were observed in APP-Swedish mutant mice hippocampal sections (Lai et al, 2009). As calreticulin is a chaperone protein responsible for proper protein folding and calcium homeostasis, a decrease of calreticulin immunoreactivity implicated dysfunction of the ER in AD brain (Taguchi et al., 2000). Production of A[beta] peptide (1-42) has to be processed by the ER. Folding of the A[beta] can cause oligomerization or fibrillization, improper folding of protein/peptide will lead ER to stress state because chaperon protein will leave ER attempting to protect improper folded protein/peptide. Our preliminary data on the APP-Swedish mutant rat retina showed that there was detectable inner retinal neuronal loss in the RGCL and the INL since 10 months of age, and significant neuronal loss can be detected in the 27 months old Tg mice when compared to age-matched control (Please refer to Fig. 1 , 2 in Preliminary Data in Attachment). Since APP and A[beta] deposition in the inner retinal neurons have been detected in this Tg mice (Ning et al., 2008), we hypothesis that A[beta] deposition induced inner retinal neurons involve ER stress signaling. As a central player in many apoptotic pathways, ER stress-induced apoptosis is a complex and heterogeneous process, involving activation of ER-associated initiator caspases, mitochondrial permeabilization and multiple BH3-only proteins (Heath-Engel et al, 2008). ER-stress also can be transmitted to mitochondrial stress because of Bad/Bcl-2 and Ca2+ release from the ER (Elyaman et al, 2002). In addition to the stress signals from the ER, accumulation of A[beta] in the synapses may cause mitochondrial stress leading to disruption of mitochondria membrane. Release of cytochrome oxidase IV (COX IV) and cytochrome-C and/or translocation of apoptosis-inducing factor (AIF) from mitochondria to the nucleus will serve as the index of mitochondrial stress. In NMDA or acute high ocular pressure induced apoptotic retinal cell loss, ER stress is involved (Shimazawa et al, 2007). On the other hand, research in our lab has shown that in hippocampal neuronal culture, low molecular weight A[beta] induces collapse of ER and this further triggers induction of autophagy (Lai et al, 2009). Therefore, we will also detect the involvement of autophagy in this Tg mice and the downstream signaling changes under ER stress. Our study will investigate the temporal relationship of ER stress and mitochondria stress signaling with the apoptosis or autophagy in the Tg retina. Microtubule (MT)-stabilizing agent Taxol that has been shown to partially attenuate collapse of the ER in vitro, we will try to apply it by intravitreous injection and evaluate the neuroprotective effect in the retina. The result obtained from this proposed project should provide information underlying the signaling pathway of how A[beta] peptides induced retinal neurodegeneration via ER stress signaling. References Blanks JC, Hinton DR, Sadun AA, Miller CA. Retinal ganglion cell degeneration in Alzheimer’s disease. Brain Res. 1989;501:364–372. Blanks JC, Torigoe Y, Hinton DR, Blanks RH. Retinal pathology in Alzheimer’s disease. I. Ganglion cell loss in foveal/parafoveal retina. Neurobiol Aging. 1996 (a);17:377–384. Blanks JC, Schmidt SY, Torigoe Y, Porrello KV, Hinton DR, Blanks RH. Retinal pathology in Alzheimer’s disease. II. Regional neuron loss and glial changes in GCL. Neurobiol Aging. 1996 (b);17:385–395. Brookmeyer R, Johnson E, Ziegler-Graham K, MH Arrighi (July 2007). Forecasting the global burden of Alzheimer’s disease Alzheimer's and Dementia 3 (3): 186–91. Curcio CA, Drucker DN. Retinal ganglion cells in Alzheimer’s disease and aging. Ann Neurol. 1993;33:248–257. Davies DC, McCoubrie P, McDonald B, Jobst KA. Myelinated axon number in the optic nerve is unaffected by Alzheimer’s disease. Br J Ophthalmol. 1995;79:596–600 Dutescu R., Li Q.-X, Crowston J, Masters CL, Baird PN, and Culvenor JG. Amyloid precursor protein processing and retinal pathology in mouse models of Alzheimer’s disease. Graefe's Arch Clind Exp Ophthalmol., 2009 Elyaman W, Terro F, Suen K-C, Yardin C, Chang RC-C, Hugon J. BAD and Bcl-2 regulation are early events linking neuronal endoplasmic reticulum stress to mitochondria-mediated apoptosis. Mol Brain Res 2002;109:233-238. Heath-Engel HM, Chang NC, Shore GC. The endoplasmic reticulum in apoptosis and autophagy: role of the BCL-2 protein family. Oncogene 27:6419-6433. Hinton DR, Sadun AA, Blanks JC, Miller CA. Optic-nerve degeneration in Alzheimer’s disease. N Engl J Med. 1986;315:485–487. Katayama T, Imaizumi K, Manabe T, Hitomi J, Kudo T, Tohyama M. Induction of neuronal death by ER stress in Alzheimer's disease. J Chem. Neuroanat., 2004;28:67-78. Lai CS-W, Preisler J, Baum L, et al. Low molecular weight A[beta] induces collapse of endoplasmic reticulum. Mol Cell Neurosci 2009;41:32-43. Ning A, Cui J, To E, Ashe KH, Matsubara J. Amyloid-beta deposits lead to retinal degeneration in a mouse model of Alzheimer disease. Invest Ophthalmol Vis Sci. 2008;49(11):5136-43. Sadun AA, Bassi CJ. Optic nerve damage in Alzheimer’s disease. Ophthalmology. 1990;97:9–17. Shimazawa M, Inokuchi Y, Okuno T, Nakajima Y, Sakaguchi G, Kato A, Oku H, Sugiyama T, Kudo T, Ikeda T, Takeda M, Hara H. Reduced retinal function in amyloid precursor protein-over-expressing transgenic mice via attenuating glutamate-N-methyl-d-aspartate receptor signaling. J Neurochem 2008;107:279-290. Taguchi J, Fujii A, Fujino Y, Tsujioka Y, Takahashi M, Tsuboi Y, Wada I, Yamada T. Different expression of calreticulin and immunoglobulin binding protein in Alzheimer's disease brain. Acta Neuropathol. 2000 Aug;100(2):153-60.

List of Research Outputs

Chang R.C.C., Chiu K., Ho Y.S. and So K.F., Modulation of neuroimmune responses on glia in the central nervous system: implicaion in therapeutic intervention against neuroinflammation, Cellular and Molecular Immunology. 2009, 6(5): 317-326.

Chiu K., Yeung S.C., Ho Y.S., Lok C.K.M., Chan W., So K.F. and Chang R.C.C., IL-10 improves retinal ganglion cell survival in experimental glaucoma model via up-regulation of IGF-1 signaling, Hong Kong Society for Immunology 2010 Annual General Meeting and Scientific Meeting, April 17, 2010.. 2010, 14.

Chiu K., Yeung S.C., So K.F. and Chang R.C.C., Modulation of morphological changes of microglia and neuroprotection by monocyte chemoattractant protein-1 in experimental glaucoma, Cellular and Molecular Immunology. 2010, 7: 61-68.

Chiu K., Zhou Y., Yeung S.C., Lok C.K.M., Chan O.O.C., Chang R.C.C., So K.F. and Chiu J., Up-regulation of crystallins is involved in the neuroprotective effect of wolfberry on survival of retinal ganglion cells in rat ocular hypertension model, Journal of Cellular Biochemistry. 2010, 110: 311-320.

Hong S.J., Chiu K., Ho Y.S., He Y., Che C.T., So K.F., Lin Z.X. and Chang R.C.C., Significance of chrysin from a cognitive-enhanching chinese herb Alphinae oxyphyllae as a source of potential neuroprotective agent, 5th International Symposium on Healthy Aging. 2010, Page 54.

Mi X., Chiu K., Van G., Leung J.W.C., Lo A.C.Y., Chung S.K., Chang R.C.C. and So K.F., The effect of lycium barbarum (wolfberry) on the expression of endothelin-1 and its receptors in an ocular hypertension model of glaucoma, 5th International Symposium on Healthy Aging. 2010, Page 55.

Researcher : Chiu YT

List of Research Outputs

Chua C.W., Chiu Y.T., Yuen H.F., Chan K.W., Man K., Wang X., Ling M.T. and Wong Y.C., Suppression of androgen-independent prostate cancer cell aggressiveness by FTY720: validating Runx2 as a potential antimetastatic drug screening platform, Clinical Cancer Research. 2009, 15(13): 4322-4335.

Luk S.U., Yap W.N., Chiu Y.T., Lee D.T.W., Ma S.K.Y., Lee K.W., Vasireddy R.S., Wong Y.C., Ching Y.P., Nelson C.O.L.L.E.E.N., Yap Y.L. and Ling M.T., Gamma-tocotrienol as an effective agent in targeting prostate cancer stem cell-like population, International Journal of Cancer. 2010.

Yuen H.F., Chiu Y.T., Chan K.K., Chua C.W., McCrudden C.M., Tang K.H., El-Tanani M., Wong Y.C., Wang X. and Chan K.W., Prostate Cancer Cells Modulate Osteoblast Mineralisation And Osteoclast Differentiation Through Id-1 , British Journal of Cancer. 2010, 102: 332-341.

Researcher : Chiu YT

List of Research Outputs

Researcher : Chu TH

Project Title:	Neuroscience 2009 The use of neurotrophic factors in acellular nerve graft for axonal regeneration after avulsion
Investigator(s):	Chu TH
Department:	Anatomy
Source(s) of Funding:	URC/CRCG - Conference Grants for Teaching Staff
Start Date:	10/2009
Completion Date:	10/2009

Abstract:

N/A

Project Title:	Effects of trophic factor on Schwann cell migration for spinal root avulsion injury repair
Investigator(s):	Chu TH, Wu W
Department:	Anatomy
Source(s) of Funding:	Small Project Funding
Start Date:	11/2009

Abstract:

The overall objective of the proposed study is to find out how neurotrophic factors affect axonal regeneration into nerve graft after implanting into avulsed spinal cord. The long term goal is to find out strategies to promote axonal regeneration across the central nervous system - peripheral nervous system interface. Spinal root avulsion, often resulted from motor vehicle accidents and obstetric complications, is the most severe type of brachial plexus injuries in humans. It involves tearing the rootlets away from the spinal cord. Motoneurons degenerate and die if left unattended. Sensory and motor functions will be compromised or completely lost in the affected arm with different degrees of injury. One of the strategies used is palliative surgeries such as nerve and muscle transfers. Another is direct repair such as reimplanting the avulsed rootlets or bridging the spinal cord and distal nerves with nerve graft. The major difference is that direct repair rescues and uses the motoneurons in avulsed segment(s) for rebuilding neural circuit. However both approaches except re-implantation of rootlets require healthy donor nerves or muscles from the patients. We and others showed that implantation of nerve graft/ re-implantation of ventral root after avulsion promotes survival and axonal regeneration of motoneurons in animal models. Recent reports suggested that modifying or enriching the peripheral component such as chondroitinase treatment or trophic factor delivery further encourage axonal outgrowth. In our recent study, we showed that injecting neurotrophic factors into the nerve graft enhances the survival and axonal regeneration of motoneurons after implanting into the avulsed spinal cord. However whether the trophic factors act directly on axons or indirectly on Schwann cells to achieve enhanced regeneration is unknown. In our previous model, we harvested fresh peripheral nerve (PN) graft which had denervated Schwann cells. It is well known that these Schwann cells up-regulated a panel of trophic factors. To eliminate the effects of existing Schwann cells and possible interaction with various factors released by the resident cells, we are going to use acellular peripheral nerve (APN) graft which leaves no viable cells prior to implantation. APN provides a suitable conduit for axonal regeneration and/ or Schwann cell migration, either together or independently. Therefore it is a useful model to investigate the effects of trophic factors on either component. Results from our pilot study showed that injecting glial cell line-derived neurotrophic into the APN prior implantation allow Schwann cells populated and axons grew into the dead nerve graft. The encouraging results prompt us to consider using acellular nerve graft for bridging spinal cord and distal nerve. Since clinically no artificial nerve graft is available for such purpose, in addition, large amount of nerves can be harvested from cadaver which solved the problem of limited choice of autologous nerves. If more funds are available in the future, we can screen for combination of neurotrophic factors which have the ability to further enhance axonal regeneration into the acellular nerve graft. It is likely to act as a template for designing the artificial nerve graft for avulsion injury in the future.

List of Research Outputs

Chu T.H. and Wu W., Use Of Gdnf In Acellular Nerve Graft For Axonal Regeneration After Spinal Root Avulsion, Society for Neuroscience 2009.

Yuan Q., Hu B., Wu Y., Chu T.H., Su H., Zhang W., So K.F., Lin Z. and Wu W., Induction of c-Jun phosphorylation in spinal motoneurons in neonatal and adult rats following axonal injury, Brain Research. 2010, 1320: 7-15.

Researcher : Chua CW

List of Research Outputs

Chua C.W., Chiu Y.T., Yuen H.F., Chan K.W., Man K., Wang X., Ling M.T. and Wong Y.C., Suppression of androgen-independent prostate cancer cell aggressiveness by FTY720: validating Runx2 as a potential antimetastatic drug screening platform, Clinical Cancer Research. 2009, 15(13): 4322-4335.

Yuen H.F., Chiu Y.T., Chan K.K., Chua C.W., McCrudden C.M., Tang K.H., El-Tanani M., Wong Y.C., Wang X. and Chan K.W., Prostate Cancer Cells Modulate Osteoblast Mineralisation And Osteoclast Differentiation Through Id-1 , British Journal of Cancer. 2010, 102: 332-341.

Researcher : Chua CW

List of Research Outputs

Researcher : Chung SK

Project Title:	Conditional knockout of osmotic responsive element binding protein, OREBP/NFAT5/TonEBP, to study its role in brain edema and infarct after ischemic stroke: a leading cause of mortality and morbidity
Investigator(s):	Chung SK
Department:	Anatomy
Source(s) of Funding:	General Research Fund (GRF)
Start Date:	01/2007

Abstract:

To determine the role of OREBP in brain water content, edema and infarct after ischemic stroke using two lines of heterozygous OREBP knockout mice derived from 2-independent ES cells; to determine the molecular signals downstream to OREBP in contributing to astrocyte and neruronal cell death during ischemic and hypertonic stress using primary astrocyte and neuronal cultures from embryos of homozygous OREBP-deficient mice; to investigate the effects of conditional deletion of OREBP in astrocytes or neurons on brain edema and infarct after ischemic stroke.

Project Title:	Role of Epac1, cAMP-regulated guanine nucleotide exchange factor 1, in blood brain barrier maintenance, infarct and neurological deficits during ischemia/reperfusion injury
Investigator(s):	Chung SK
Department:	Anatomy
Source(s) of Funding:	General Research Fund (GRF)
Start Date:	01/2009

Abstract:

(1) To investigate the mechanisms of Epac1 contribution in BBB integrity and infarct during acute stroke injury by using Epac1 knockout mice and Epac analogue; (2) To determine whether the severe BBB breakdown and infarct with acute ischemic stroke seen in GET-1 and TET-1 transgenic mice are mediated by Epac1; (3) To determine how Epac1 contribute to the post-stroke delayed dementia by using Epac1 knockout mice and Epac-selective analogue.

Project Title:	Start Domain-Containing Protein 13, STARD13, RhoA GTPase-activating protein in painful neuropathy: common and debilitating complication of diabetes.
Investigator(s):	Chung SK
Department:	Anatomy
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	03/2010

Abstract:

Objectives: The current project has three main interrelated but independent objectives, but is to say, that the outcome of one objective should not affect the progress of the other objectives: 1. To determine the role of STARD13 in sensory and inflammatory pain under normal and diabetic condition 2. To investigate the altered downstream signaling pathway in the nervous system of normal and diabetic STARD13-deficient mice. 3. Blocking of RhoA with bacterial toxin C3 transferease to confirm the in vivo contribution of STARD13 on the activation of RhoA and painful neuropathy

List of Research Outputs

Chen A.Y.S., Chung S.S.M. and Chung S.K., Aldose reductase deficiency improves wallerian degeneration and nerve regeneration in diabetic thy1-YFP mice, Journal of Neuropathology & Experimental Neurology:. 2010, 69(3): 294-305.

Li H., Lam A.K.Y., Xu A., Lam K.S.L. and Chung S.K., High dosage of Exendin-4 increased early insulin secretion in differentiated beta cells from mouse embryonic stem cells, Acta Pharmacol Sin. 2010, 31(5): 570-7.

Li Q., Cheung C., Hui E.S., Feldon J., Meyer U., Chung S.K., Chua S.E., Sham P.C., Wu E.X. and McAlonan G.M., Prenatal Immune Challenge Is an Environmental Risk Factor for Brain and Behavior Change Relevant to Schizophrenia: Evidence from MRI in a Mouse model, PLOSone. 2009, e6354.

Lo A.C.Y., Fu Z., Li S.Y., Wong D.S.H. and Chung S.K., Genetic Deletion Of Aldose Reductase Protects The Neonatal Mouse Retina From Oxygen-induced Retinopathy, ARVO 2010 Annual Meeting. 2010.

Mi X., Chiu K., Van G., Leung J.W.C., Lo A.C.Y., Chung S.K., Chang R.C.C. and So K.F., The effect of lycium barbarum (wolfberry) on the expression of endothelin-1 and its receptors in an ocular hypertension model of glaucoma, 5th International Symposium on Healthy Aging. 2010, Page 55.

Tang W.H., Cheng W.T., Kravtsov G.M., Tong X.Y., Hou X.Y., Chung S.K. and Chung S.S.M., Cardiac contractile dysfunction during acute hyperglycemia due to impairment of SERCA by polyol pathway-mediated oxidative stress, American Journal of Physiology and Cell Physiology. 2010, 299: C643-C653.

Tang W.H., Kravtsov G.M., Sauert M., Tong X.Y., Hou X.Y., Wong T.M., Chung S.K. and Chung S.S.M., Polyol pathway impairs the function of SERCA and RyR in ischemic-reperfused rat hearts by increasing oxidative modificaitons of these proteins, Journal of Molecular and Cellular Cardiology. 2010, 49: 58-69.

Tong H.Y., Guo J.J., Xu S.X., Mak M.C., Chung S.K., Chung S.S.M., Huang A.L. and Ko B.C.B., Inducible nucleosome depletion at OREBP-binding-sites by hypertonic stress, PLoS ONE. 2009, 4(12): e8435.

Yagihashi S., Mizukami H., Ogasawara S., Yamagishi S.I., Nukada H., Kato N., Hibi C., Chung S.K. and Chung S.S.M., The role of the polyol pathway in acute kidney injury caused by hindlimb ischaemia in mice, Journal of Pathology. 2010, 220: 530-541.

Yau T.O., Leung T.H.Y., Lam S.G.S., Cheung O.F., Tung K.K., Khong P.L., Lam A.K.M., Chung S.K. and Ng I.O.L., Deleted in liver cancer 2 (DLC2) was dispensable for development and its deficiency did not aggravate hepatocarcinogenesis., PLoS One. 2009, 4(8): e6566.

Yeung C.M., Lo A.C.Y., Cheung A.K.H., Chung S.S.M., Wong D.S.H. and Chung S.K., More severe type 2 diabetes-associated ischemic stroke injury is alleviated in aldose reductase-deficient mice, Journal of Neuroscience Research. 2010, 88: 2026-2034.

Yeung P.K.K., Lo A.C.Y., Leung J.W.C., Chung S.S.M. and Chung S.K., Targeted overexpression of endothelin-1 in astrocytes leads to more severe cytotoxic brain edema and higher mortality, Journal of Cerebral Blood Flow & Metabolism. 2009, 29: 1891-1902.

Zhang X., Lam K.S.L., Chung S.K. and Xu A., Hypoxia Inducible Factor 1α Plays An Indispensible Role In Maintaining The Thermogenic Functions Of Brown Adipose Tissue In Mice, Endocrine Society Annual Meeting, 19-22 June, San Diego, USA. 2010.

Zhang X., Lam K.S.L., Chung S.K. and Xu A., Hypoxia Inducible Factor 1 Plays an Indispensible Role in the Thermogenic Functions of Brown Adipose Tissue in Mice, Diabetes. 2010, 59 supplement 1: A47.

Researcher : Deng W

List of Research Outputs

Cheung P.P.Y., Deng W., Man C.W.Y., Tse W.W., Srivastava G., Law S.Y.K., Tsao G.S.W. and Cheung A., Genetic alterations in a telomerase-immortalized human esophageal epithelial cell line: Implications for carcinogenesis, Cancer Letters. 2010, 293: 41-51.

Liang Y., Zhong Z., Huang Y., Deng W., Cao J., Tsao G.S.W., Liu Q., Pei D., Kang T. and Zeng Y.X., Stem-like cancer cells are inducible by increasing genomic instability in cancer cells, The Journal of Biological Chemistry. 2010, 285(7): 4931-4940.

Tsang C.M., Zhang G., Seto E., Takada K., Deng W., Yip Y.L., Man C.W.Y., Hau P.M., Chen H., Cao Y., Lo K.W., Middeldorp J.M., Cheung A. and Tsao G.S.W., Epstein-Barr virus infection in immortalized nasopharyngeal epithelial cells: Regulation of infection and phenotypic characterization. , International Journal of Cancer. 2010, 127: 1570-1583.

Tsang C.M., Zhang G., Seto E., Takada K., Deng W., Yip Y.L., Man C.W.Y., Hau P.M., Cao Y., Lo K.W. and Middeldorp J.M., Epstein-Barr virus infection in immortalized nasopharyngeal epithelial cells: Regulation of infection and phenotypic characterization, Int. J. Cancer. 2010, 127: 1570-83.

Tsao G.S.W., Tsang C.M., Zhang G., Deng W., Hau P.M., Man C.W.Y., Kenzo T., Chen H., Yip Y.L., Lo K.W., Cao Y. and Cheung A., Epstein-Barr virus infection confer stress-resistant property in immortalized nasopharyngeal epithelial cells., Proceedings of American Association of Cancer Research. 2010.

Yip Y.L., Tsang C.M., Jin Y., Deng W., Man C.W.Y., Cheung P.P.Y., Chen H., Cheung A. and Tsao G.S.W., The Epstein-Barr virus-encoded LMP1 extended the life span and immortalized nasopharyngeal epithelial cells., Hong Kong International Cancer Congress . 2009.

Researcher : Di K

List of Research Outputs

Tsang C.M., Lau P.W.E., Di K., Cheung P.P.Y., Hau P.M., Ching Y.P., Wong Y.C., Cheung A., Wan T.S.K., Tong Y., Tsao G.S.W. and Feng Y., Berberine inhibits Rho GTPases and cell migration at low doses but induces G2 arrest and apoptosis at high doses in human cancer cells, International Journal of Molecular Medicine. 2009, 24: 131-138.

Researcher : Du Y

List of Research Outputs

Du Y. and Yip H.K.F., Bone Morphogenetic Protein Signaling Activates Id Genes in the Mouse Retinal Progenitor Cells, Hellenic Society for Neuroscience. 2009.

Du Y. and Yip H.K.F., Differentiation plasticity of neural stem cells in the injured adult mouse spinal cord is regulated by bone morphogenetic proteins (BMPs), Hellenic Society for Neuroscience. 2009.

Du Y. and Yip H.K.F., Effects Of Bone Morphogenetic Protein 2 On Id Expression And Neuroblastoma Cell Differentiation, Differentiation. Elsevier, 2010, 79: 84-92.

Du Y., The role of inhibitors of differentation (Id) and BMP/Smad signaling pathway in retinal cell development. 2009, 179 pages.

Xiao Q., Du Y., Wu W. and Yip H.K.F., Bone Morphogenetic Proteins Mediate Cellular Response And, Together With Noggin, Regulate Astrocyte Differentiation After Spinal Cord Injury, Experimental Neurology. Elsevier, 2010, 221: 353-366.

Yip H.K.F. and Du Y., Activation Of Id Genes By Bmp Signaling Influences Proliferation And Cell Fate Choices Of Retinal Progenitors, The Association for Research in Vision and Ophthalmology Annual Meeting. 2010.

Researcher : Ellis-Behnke RG

Project Title:	Development of a new frontier in nanomedicine
Investigator(s):	Ellis-Behnke RG, Wong KKY, So KF, Che CM, Ngan AHW, Chan LC, Vanhoutte PMGR
Department:	Anatomy
Source(s) of Funding:	Guangdong-Hong Kong Technology Cooperation Funding Scheme
Start Date:	10/2007
Completion Date:	09/2009

Abstract:

To explore different approaches in peptide synthesis and modify the existing processes to optimize the manufacture of nano materials for research in nanomedicine; to carry out characteriazation tests and categorization of nano materials for setting up an evaluation and standardization system for nano medicine; to manufacture nano materials with quality assurance/quality control (QA/QC) to ensure purity and safety; to develop manufacturing strategies to enhance the production of nano materials effectiveness, efficiently and quickly; to put the nano materials through the ADME system of analysis and evaluation for their safety in animals and human applications.

Project Title:	The ADME of Self-assembling Nanomaterials
Investigator(s):	Ellis-Behnke RG
Department:	Anatomy
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	06/2008

Abstract:

The objectives of this proposed exploratory study are: • To investigate the feasibility of adopting the ADME model into understanding the mechanisms of nanomaterials working inside the body. • To apply standard ADME test protocols to study these mechanisms which will potentially bring new understandings towards the intersection of nanomaterials and medicine. • To obtain preliminary data which will potentially offset further in-depth research programmes that are of great interest in the field of nanomedicine for GRF and NIH proposals. Absorption, distribution, metabolism, and excretion (ADME) form the well-established basic mechanism that is used to describe the pharmacokinetics (PK) and pharmacology (PD) of a pharmaceutical compound within an organism. In this exploratory study, a series of ADME tests are designed to determine the fate of a given compound, nanomaterial in this case, following its application; and to evaluate its safety for human use. These tests are usually used for therapeutics. However they need to be performed on medical devices if these devices are at the molecular (nano) scale. In our systematic body of research in self-assembling nanomaterials (see references below), we have found that when these materials come into contact with tissues, they would enhance molecular repair of the brain and the spinal cord 1,2,3,4,5,7,8; promote axonal repair4,5; and also bring about immediate hemostasis6. Adopting the basics of ADME, this pilot study will further our understandings towards the interactions between the materials and the tissues and any residual effects to the organism caused by the materials being tested. It is important not just being able to measure the interaction, but also tracking down the short- and long-term movement of these materials into and out of the cells in the body. We will produce the materials using our peptide synthesizer. These peptides will be tested with several different cell types to extrapolate their interactions and residual effects at varying concentrations. We will also track down where they localize in different cell types. Administering these materials into the body, the kinetics of their ADME will be followed over time using MRI as well as histochemical assays. This study will allow us a platform to examine and evaluate the PK and PD of the materials following its administration; to understand how they interact with their immediate environment both outside and inside the cell; and how they are degraded in the body. The preliminary findings will enable us to secure future funding from the GRF and NIH for in-depth research which will lead to new and fundamental understandings towards self-assembling nanomaterials and its promising application in medicine, fortifying our pioneering position in the field.

Project Title:	Incorporation Dynamics of Additives and Self-assembly peptides (SAPs) at Nanoscale for Central Nervous System (CNS) Regeneration
Investigator(s):	Ellis-Behnke RG
Department:	Anatomy
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	04/2009

Abstract:

Based on our systematic approach to studying the property and application of the self-assembling peptides (SAPs), the current proposal aims to: • Examine the effectiveness of the SAP-regeneration-enhancing factor (REF) combination for CNS regeneration • Investigate the incorporative dynamics of the REF addictive into SAP in terms of assembling capability and delivery effectiveness; • Understand how different SAP-REF combinations will change the potency of the material and the local environment where the combinations are implanted; • Generate important preliminary data for publication and for support of the next GRF application. BACKGROUND My primary research focuses on the reconnection of the disconnected parts of the central nervous system (CNS) in order to restore function and quality of life. The Four Ps of CNS regeneration is a new framework that I developed for approaching CNS injury [2] based on extensive literature research supported by my own research findings on using self-assembling peptides for brain repair [5, 8, 9]. The determining factor in functional recovery was once believed to be the amount of innervation. However, we now know that the level of recovery is determined not only by the number of axons but also the local density of their connections and the rehabilitation work performed to drive reinnervation and refinement through training. Four distinct issues must be addressed for successful CNS regeneration to occur: (1) Preserve: how to keep neurons with damaged axons alive long enough to re-grow and obtain functional regeneration; (2) Permit: how to create a permissive environment that will allow axons to grow through the site of the lesion; (3) Promote: how to promote axon growth in the correct direction coincident with the onset of the permissive environment; and (4) Plasticity: how to promote changes in morphology in vivo to ensure that the axon connections are functional in the target, mapped correctly, and sufficient to drive behavior. Using the framework of the four P’s can speed up the regeneration process, lessening the time from injury to return of function. Our recent discoveries have demonstrated that self-assembling peptides (SAP) can play an integrative role in enhancing the 4P’s of CNS regeneration. SAP creates an environment that allows the brain to heal itself and reconstitute the original tissue by (1) removing the scar, (2) creating an environment that allows for bi-directional migration of surrounding tissue into the injured area and (3) creating an environment that allows axons to grow through the injury site back into the target tissue, demonstrating functional return, evidenced by behavior [4-6]. Despite these exciting results, the mechanism underlying the effectiveness of the SAP is largely unknown. Paradigmatically, nevertheless, SAP can be perceived as an essential structure/scaffold which enhances axons to re-grow in manners described by the 4P’s framework. Based on these findings, this proposal intends to further explore two interesting issues: 1) Will an addition of a regeneration enhancing factor (REF) further improve the chemical property of the SAP resulting in accelerating regeneration? If so, 2) what is the mechanism involved for such improvements. 1) SAP-REF Combination for Accelerating Regeneration Using the visual system as a model, we plan to experiment with a combination of SAP and an REF, namely ABC-Chondroitinase, to create a more permissive environment to enable a higher density of reinnervation. ABC-Chondroitinase is known to remove several components of the scar that block regeneration. In all chronic CNS injuries the scar is the primary barrier to axons reconnecting across the gap formed after injury. Despite its desirable characteristics, ABC-Chondroitinase is an unstable enzyme which breaks down quickly when injected into the injury site. To overcome this problem, we propose to enable a slow release of the enzyme by combining it with SAP. The combined material will be implanted into the brachium model for regeneration that we pioneered. Using a nanomaterial to enable a slow release of ABC-Chondroitinase has never been explored before. If successful, this could represent a new way to deliver long term therapeutics to remove scars in chronic brain-injured patients. A new treatment or a closer step towards reconnecting the disconnected parts of the CNS that will lead to restored function is thus probable. 2) Incorporation Dynamics of the SAP-REF Mixture The gross molecular structure of the ABC-Chondroitinase is sufficiently known to allow us to explore the incorporation dynamics of this REF into SAP without disrupting the self-assembly and structure. However, understanding the release characteristics and the breakdown of the SAP-REF mixture is critical to a larger animal study and vital for advancing the current discoveries into humans. It helps to map out the characteristics of the assembly process with the additive, and the possible toxic effects when these materials are combined. A systematic variation in concentration of the SAP-REF combination will be tested to investigate what constitutes the change in potency of the material and how each of these materials will react with the local environment where the combinations are implanted. With each of these manipulations the material will first be tested in vitro. Based on these preliminary results, the SAP-REF combination will then be implanted in vivo. We will observe the ability of the combination in increasing CNS regeneration. The expected finding of significant enhancements will lead to later experiments designed to identify the contributions of each manipulation. Using this logic, we will be pursuing the twin goal of maximum behavioral recovery alongside full understanding of the mechanisms. (References in CV p.3 'Publications')

Project Title:	Self-assembling Peptides (SAPs) at Nanoscale for Blood Preservation
Investigator(s):	Ellis-Behnke RG
Department:	Anatomy
Source(s) of Funding:	Seed Funding Programme for Applied Research
Start Date:	06/2009

Abstract:

Introduction Presently whole blood is preserved and stored in refrigerator at near freezing temperature and has a shelf life of about a month. To prolong its shelf life, whole blood is also separated into constituent parts and stored with additives. By so doing, it can be extended to a shelf life of up to 6 weeks. Further extension of the viability of blood over a longer period of time can be achieved if kept frozen at subfreezing temperature. However, this practice is time consuming and expensive, and may not be affordable in many places and situations. The challenge of having the right amount, quality and type is particularly serious in remote areas or traumatic conditions caused by accidents or natural disasters. Shortage of readily available blood or wastage of thawed blood is a costly problem [1]. Potential of Nanopeptide for Blood Preservation at Room Temperature Our serendipitous discovery has shown that, at room temperature, whole blood can be kept in a nanoscale self-assembling peptide (SAP) medium for a much longer period of time than that preserved by conventional methods [2, 3]. The implications of this discovery to blood preservation, management and logistics deserve scientific, evidence-based investigation. The potential of extending shelf life, convenience of storage and instant availability would mean great saving of resources and prevention of wastage of precious blood. Our Research Work on Blood and Initial Discovery in Blood Preservation with SAP In 2004 we discovered that a designed nanoscale self-assembling peptide material stopped bleeding in less than 15 seconds after application in the brain of mammals, without any apparent detrimental effects to the surrounding tissue [4]. A systematic body of studies has since been conducted where several designed self-assembling peptides (SAPs) that spontaneously form nanofibers were examined. SAPs are synthetic biological materials formed through the assembly of ionic self-complementary peptides and are designed using alternating positive and negative L-amino acids that form highly hydrated scaffolds in the presence of physiological-concentration salts, i.e., saline, tissue culture media, physiological solutions or human bodily fluids such as blood [5-9]. Our experimental paradigms demonstrate that complete hemostasis can be achieved in less than 15 seconds after 1) a transection of a blood vessel leading to the branch of the superior sagittal sinus in both hamsters and rats; 2) a femoral artery cut; 3) a sagittal transection of the left lateral liver lobe; 4) a transverse transection of the left liver lobe involving cutting a primary branch of the portal vein; 5) a 4 mm liver punch biopsy and 6) multiple 4mm skin punch biopsies on nude mice. Take one of our liver experiments for example. We made a transverse cut in the left lobe of the liver and severed a major branch of the portal vein. Four concentration levels of SAP-1 were tested (n=12) along with 4 control animals. On application of 400 µl of 4% concentration SAP-1, bleeding stopped in 11.0 + 1.0 seconds. We duplicated the test successfully with 400 µl of 3% or 2% (10 + 1.0 and 10.3 + 0.5 seconds) respectively. However, when the same volume of only 1% was applied, bleeding continued for 86.6. + 20.8 seconds. In the controls, bleeding continued for 377.5 + 85.0 seconds. The dose-response results suggest that animals treated with 2% or higher concentration SAP-1 solution resulted in no increase in speed of hemostatic activity in a high flow environment. ANOVA showed a significant difference between the SAP-1 treated animal groups and the control group (f= 45.91 DF = 4, p<0.0001; Tunkey test at a 99% confidence interval). The ability of SAPs to bring about hemostasis surpasses any of the conventional practice in the field and we have gained recognized expertise in researching with blood. Whilst analyzing these results from our hemostasis studies, we discovered that when SAP was applied, there was an absence of the normal clotting cascade. No aggregate of platelets was found at the wound site, blood in the vessel continued to flow and the red blood cells were not lysed when in contact with SAP. We have also discovered that an injection of 1% SAP intravenously in rodents would not cause thrombosis or thrombi formation that might induce circulatory complications. Together with the advantages of a much extended period of preservation and the convenience of storage at room temperature, all these have prompted us to think about applying SAPs for blood preservation. The implication for a considerable reduction in energy consumption for storage and the convenience of transferring and transporting blood from reserve to end use is desirable. It would also mean a more efficient management of precious blood with minimized wastage across the blood industry. Objectives of the Current Proposal We are approaching blood preservation from a new direction with a huge potential in revolutionizing the concept and methods currently in use. Our aim for the current proposal is to determine how long and in what way blood will react when kept in an environment of SAPs under various conditions. Bearing in mind its possible application in the blood industry, the objectives of the current proposals are: 1. to explore the possibility of SAP as a blood preserving agent at room temperature for a significantly extended period of time; 2. to determine the best SAP condition for optimizing the viability of blood; 3. to evaluate the effect of re-perfusion of SAP-preserved blood. Ultimately, we hope to obtain substantial data for securing an ITF fund for the development SAPs as preferred blood-preserving agents/products in industry. (References in Section X: Critical Success Factors)

Project Title:	20th International Offshore (Ocean) and Polar Engineering Conference (ISOPE 2010) THE CONTROL OF GROWTH AND DIFFERENTIATION OF CELLS WITH PHYSICAL INTERACTION
Investigator(s):	Ellis-Behnke RG
Department:	Anatomy
Source(s) of Funding:	URC/CRCG - Conference Grants for Teaching Staff
Start Date:	06/2010
Completion Date:	06/2010

Abstract:

N/A

List of Research Outputs

Ellis-Behnke R.G., Associate Editor/Neurology, Nanomedicine: Nanotechnology, Biology and Medicine. 2010.

Ellis-Behnke R.G., Control and preservation of tissue after hemorrhagic stroke using nano materials, 1st Annual Conference of the American Society of Nanomedicine, Potomac, MD. 2009.

Ellis-Behnke R.G., Liang Y., Cheung W.H. and Tay D.K.C., Controlling The Growth And Differentiation Of Cells With Physical Interaction, Nanobiotech 2009.

Ellis-Behnke R.G., Controlling the growth and differentiation of cells with physical interaction, Keynote Speaker, Nanobiotech 2009, Troy, NY. 2009.

Ellis-Behnke R.G., Liang Y., Guo J., Tay D.K.C., Schneider G.E., Teather L.A., Wu W. and So K.F., Forever young: how to control the elongation, differentiation and proliferation of cells using nanotechnology, Cell Transplantation. 2009.

Ellis-Behnke R.G., Cheung W.H., Liang Y. and Liang Y., Nanomedicine and nanotechnology applied to neurosciences, 4th International Multidisciplinary Congress on Intensive and Critical Care Medicine. 2009.

Ellis-Behnke R.G., Nanomedicine and nanotechnology applied to neurosciences, 4th International Multidisciplinary Congress on Intensive and Critical Care Medicine, Mexico City, Mexico. 2009.

Ellis-Behnke R.G., Cheung W.H., Liang Y. and Tay D.K.C., Nanoscale Image Contrast Agents To Enhance The Visualization Of Regenerating Cns Axons, Presidential Symposium on Nanotechnology at the 51st Meeting of the American Society for Therapeutic Radiology and Oncology (ASTRO). 2009.

Ellis-Behnke R.G., Nanoscale image contrast agents to enhance the visualization of regenerating CNS axons, Presidential Symposium on Nanotechnology at the 51st Meeting of the American Society for Therapeutic Radiology and Oncology (ASTRO). 2009.

Ellis-Behnke R.G., Liang Y., Cheung W.H., So K.F., Wu W. and Tay D.K.C., Redefining tissue engineering for nanomedicine: Visualizing the progress of regenerating axons in the mammalian visual system after complete transection and treatment with self-assembling nanomaterial, 6th Annual World Congress for Brain Mapping and Image Guided Therapy, Harvard Medical School, Boston MA. 2009.

Ellis-Behnke R.G., Redefining tissue engineering for nanomedicine: Visualizing the progress of regenerating axons in the mammalian visual system after complete transection and treatment with self-assembling nanomaterial, Nanomedicine Session at the 6th Annual World Congress for Brain Mapping and Image Guided Therapy, Boston MA. 2009.

Ellis-Behnke R.G., Redefining tissue engineering for nanomedicine, U.S. Ophthalmic Review. 2009.

Ellis-Behnke R.G., Regenerative Medicine, Institute of Nanotechnology - Nanomedicine Visions for the Future, Amsterdam, Netherlands. 2010.

Ellis-Behnke R.G., Cheung W.H., Tay D.K.C., Liang Y., Lui Kau K.W.F., Schneider G.E. and So K.F., The control of stem cells in the brain and spinal cord by extracellular nanomatrix system, Society for Neuroscience, Chicago. 2009.

Ellis-Behnke R.G., Liang Y., Cheung S.W.H., So K.F. and Tay D.K.C., Using a self-assembling nanopeptide to achieve ocular hemostasis without causing clotting or secondary inflammation, ARVO 2010. Program No. 427, Poster No. D1131.

Ellis-Behnke R.G., Liang Y., Cheung W.H. and Tay D.K.C., Using nanotechnology to control the elongation, differentiation and proliferation of cells, 16th Annual Optic Nerve Rescue and Restoration Think Tank. 2009.

Nan Y., Xiao C., Chen B., Ellis-Behnke R.G., So K.F. and Pu M., Visual response properties of Y cells in the detached feline retina, Investigative Ophthalmology & Visual Science. 2010, 51(2): 1208-1215.

So K.F., Liang Y., Tay D.K.C. and Ellis-Behnke R.G., Nanomedicine for CNS regeneration and instant hemostasis, WACBE World Congress on Bioengineering 2009, July 26-26, 2009, Hong Kong. 2009, 4.

Woo P.C.Y., Lau S.K.P., Choi K.Y., Fung H.T., Shek K.C., Miao J., Chan B.Y.L., Ng K.H.L., Ngan H.Y., Ellis-Behnke R.G., Que T.L., Kam C.W. and Yuen K.Y., Resequencing microarray for detection of human adenoviruses in patients with conjunctivitis, Journal of Clinical Virology. 2010, 47: 282-285.

Yuan T., Liang Y., Tay D.K.C., So K.F. and Ellis-Behnke R.G., Olfactory tract transection enhances adult neurogenesis in piriform cortex, 22nd Biennial Meeting of the International Society of Neurochemistry, Busan Korea. 2009.

Researcher : Fu Q

List of Research Outputs

Fu Q., Li X., Yip H.K.F., Shao Z.H., Wu W., Mi X. and So K.F., Combined effect of brain-derived neurotrophic factor and LINGO-1 fusion protein on long-term survival of retinal ganglion cells in chronic glaucoma, Neuroscience Bulletin. 2009, 25(1): 171-172.

Researcher : Fu Z

List of Research Outputs

Lo A.C.Y., Fu Z., Li S.Y., Wong D.S.H. and Chung S.K., Genetic Deletion Of Aldose Reductase Protects The Neonatal Mouse Retina From Oxygen-induced Retinopathy, ARVO 2010 Annual Meeting. 2010.

Researcher : Guo J

List of Research Outputs

Ellis-Behnke R.G., Liang Y., Guo J., Tay D.K.C., Schneider G.E., Teather L.A., Wu W. and So K.F., Forever young: how to control the elongation, differentiation and proliferation of cells using nanotechnology, Cell Transplantation. 2009.

Researcher : Hau PM

List of Research Outputs

Tsang C.M., Lau P.W.E., Di K., Cheung P.P.Y., Hau P.M., Ching Y.P., Wong Y.C., Cheung A., Wan T.S.K., Tong Y., Tsao G.S.W. and Feng Y., Berberine inhibits Rho GTPases and cell migration at low doses but induces G2 arrest and apoptosis at high doses in human cancer cells, International Journal of Molecular Medicine. 2009, 24: 131-138.

Tsang C.M., Zhang G., Seto E., Takada K., Deng W., Yip Y.L., Man C.W.Y., Hau P.M., Chen H., Cao Y., Lo K.W., Middeldorp J.M., Cheung A. and Tsao G.S.W., Epstein-Barr virus infection in immortalized nasopharyngeal epithelial cells: Regulation of infection and phenotypic characterization. , International Journal of Cancer. 2010, 127: 1570-1583.

Tsang C.M., Zhang G., Seto E., Takada K., Deng W., Yip Y.L., Man C.W.Y., Hau P.M., Cao Y., Lo K.W. and Middeldorp J.M., Epstein-Barr virus infection in immortalized nasopharyngeal epithelial cells: Regulation of infection and phenotypic characterization, Int. J. Cancer. 2010, 127: 1570-83.

Tsao G.S.W., Tsang C.M., Zhang G., Deng W., Hau P.M., Man C.W.Y., Kenzo T., Chen H., Yip Y.L., Lo K.W., Cao Y. and Cheung A., Epstein-Barr virus infection confer stress-resistant property in immortalized nasopharyngeal epithelial cells., Proceedings of American Association of Cancer Research. 2010.

Researcher : Hau PM

List of Research Outputs

Researcher : Ho MCT

List of Research Outputs

Tipoe G.L., Ho M.C.T., Liong E.C., Leung T.M., Lau T.Y.H., Fung M.L. and Nanji A.A., Voluntary oral feeding of rats not requiring a very high fat diet is a clinical relevant model of non-alcoholic fatty liver disease (NAFLD), Histology and Histopathology. 2009, 24(9): 1161-1169.

Researcher : Ho YS

List of Research Outputs

Chang R.C.C., Yang X., Ho Y.S., Yeung S.C. and Mak J.C.W., Alzheimer-like pathology in rat receiving passive smoking, Society for Neuroscience 2009. Program No. 626.13: Poster No. H26.

Chang R.C.C., Ho Y.S., Yu M.S. and So K.F., Medicinal and nutraceutical uses of wolfberry in preventing neurodegeneration of Alzheimer's disease, In: Charles Ramassamy and Stéphane Bastianetto, Recent Advances on Nutrition and the Prevention of Alzheimer's Disease, 2010. Kerala, India, Transworld Research Network, 2010, 169-185.

Chang R.C.C., Chiu K., Ho Y.S. and So K.F., Modulation of neuroimmune responses on glia in the central nervous system: implicaion in therapeutic intervention against neuroinflammation, Cellular and Molecular Immunology. 2009, 6(5): 317-326.

Chang R.C.C., Chao J., Ho Y.S. and Wang M., Neurodegeneration: the Processes, Hong Kong Medical Journal. 2009, 15(6) Suppl. 7.

Chang R.C.C., Zhang Q., Hung H.L., Cheung Y.T., Ho Y.S., Lai S.W. and Wuwongse S., Pathogenesis of Alzheimer's Disease, 5th International Symposium on Healthy Aging. 2010, Page 19.

Chao J., Lau K.W., Huie M.J., Ho Y.S., Yu M.S., Lai S.W., Wang M., Yuen W.H., Lam W.H., Chan T.H. and Chang R.C.C., A pro-drug of the green tea polyphenol (-)-epigallocatechin-3-gallate (EGCG) prevents differentiated SH-SY5Y cells from toxicity induced by 6-hydroxydopamine, Neuroscience Letters. 2010, 469: 360-364.

Chiu K., Yeung S.C., Ho Y.S., Lok C.K.M., Chan W., So K.F. and Chang R.C.C., IL-10 improves retinal ganglion cell survival in experimental glaucoma model via up-regulation of IGF-1 signaling, Hong Kong Society for Immunology 2010 Annual General Meeting and Scientific Meeting, April 17, 2010.. 2010, 14.

Ho Y.S., So K.F. and Chang R.C.C., Anti-aging herbal medicine - How and why can they be used in aging-associated neurodegenerative disease?, Ageing Research Reviews. 2010, 9: 354-362.

Ho Y.S., Investigation of Lycium Barbarum as neuroprotective drug against Alzheimer's disease. 2009, 261 pages.

Ho Y.S., Yu M.S., Yang X., So K.F., Yuen W.H. and Chang R.C.C., Neuroprotective effects of polysaccharides from wolfberry, the fruits of Lycium barbarum. against homocysteine-induced toxicity in rat cortical neurons, Journal of Alzheimer's Disease. 2010, 19: 813-827.

Ho Y.S., Yang X., Yu M.S., So K.F. and Chang R.C.C., Polysaccharides from Wolfberry (Lycium barbarum) antagonize homocysteine-induced neurotoxicity in cultured cortical neurons, Society for Neuroscience 2009. Program No. 626.3: Poster No. H16.

Ho Y.S., Yu M.S., Yik S.Y., So K.F., Yuen W.H. and Chang R.C.C., Polysaccharides from wolfberry antagonizes glutamate excitotoxicity in rat cortical neurons, Cellular and Molecular Neurobiology. 2009, 29: 1233-1244.

Ho Y.S., Yang X., Wang J., So K.F. and Chang R.C.C., The relationship between ER stress and TAU phosphorylation - Do they affect each other?, 5th International Symposium on Healthy Aging,. 2010, Page 63.

Ho Y.S., So K.F. and Chang R.C.C., Wolfberry (Lycium Barbarum) protects primary corticol neurons against Alzheimer's disease-related pathological damages, Collegium Internationale Neuro-Psychopharmacologicum (CINP) 2010 World Congress. 2010, P-08.

Hong S.J., Chiu K., Ho Y.S., He Y., Che C.T., So K.F., Lin Z.X. and Chang R.C.C., Significance of chrysin from a cognitive-enhanching chinese herb Alphinae oxyphyllae as a source of potential neuroprotective agent, 5th International Symposium on Healthy Aging. 2010, Page 54.

Hung C.H.L., Cheung Y.T., Ho Y.S. and Chang R.C.C., Intracellular organelle collapse triggered by low molecular weight b-amyloid peptides, 5th International Symposium on Healthy Aging. 2010, Page 61.

Hung H.L., Ho Y.S. and Chang R.C.C., Modulation of mitochondrial calcium as a pharmacological target for Alzheimer's disease, Ageing Research Reviews. 2010, 9: 447-456.

Jia H.S., Lin X., He Y., Che C.T., Ho Y.S. and Chang R.C.C., The neuroprotection effects of a cognitive-enhancing herb Alpinae Oxyphyllae and its component chrysin on glutamate-induced neurotoxicity, Society for Neuroscience 2009. Program No. 626.16: Poster No. H29.

Zhang N.Q., Cheung Y.T., Ho Y.S. and Chang R.C.C., Impact of low molecular weight Ab on autophagosomes and proteasomes via collapse of the endoplasmic reticulum, 5th International Symposium on Healthy Aging. 2010, Page 61.

Researcher : Ho YS

List of Research Outputs

Chang R.C.C., Yang X., Ho Y.S., Yeung S.C. and Mak J.C.W., Alzheimer-like pathology in rat receiving passive smoking, Society for Neuroscience 2009. Program No. 626.13: Poster No. H26.

Chang R.C.C., Chao J., Ho Y.S. and Wang M., Neurodegeneration: the Processes, Hong Kong Medical Journal. 2009, 15(6) Suppl. 7.

Chang R.C.C., Zhang Q., Hung H.L., Cheung Y.T., Ho Y.S., Lai S.W. and Wuwongse S., Pathogenesis of Alzheimer's Disease, 5th International Symposium on Healthy Aging. 2010, Page 19.

Ho Y.S., So K.F. and Chang R.C.C., Anti-aging herbal medicine - How and why can they be used in aging-associated neurodegenerative disease?, Ageing Research Reviews. 2010, 9: 354-362.

Ho Y.S., Investigation of Lycium Barbarum as neuroprotective drug against Alzheimer's disease. 2009, 261 pages.

Hung H.L., Ho Y.S. and Chang R.C.C., Modulation of mitochondrial calcium as a pharmacological target for Alzheimer's disease, Ageing Research Reviews. 2010, 9: 447-456.

Researcher : Hu B

List of Research Outputs

Yuan Q., Hu B., Wu Y., Chu T.H., Su H., Zhang W., So K.F., Lin Z. and Wu W., Induction of c-Jun phosphorylation in spinal motoneurons in neonatal and adult rats following axonal injury, Brain Research. 2010, 1320: 7-15.

Researcher : Huen MSY

Project Title:	Functional characterisation of EXPAND1 and its role in the maintenance of genome stability and tumor suppression.
Investigator(s):	Huen MSY
Department:	Anatomy
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	09/2009
Completion Date:	08/2010

Abstract:

Maintenance of genome stability is pivotal for cell survival and tumor suppression. To this end, the cell has evolved the DNA damage response protein network that coordinates DNA repair and cell cycle progression, which in concert, ensures faithful inheritance of the genetic material. Dysregulation of components involved in these cellular processes contributes to tumorigenesis. Thus, understanding of how the cell respond and cope with DNA damage not only will shed light into the molecular mechanisms that underlie carcinogenesis, but will also provide potential molecular targets for therapeutic intervention and markers for early detection of cancer development. With these in mind, we previously undertook a tandem affinity purification (TAP) approach with an aim to identify novel components in the DNA damage response pathway. Interestingly, this approach enabled the identification of EXPAND1 as a novel component residing in the tumor suppressor p53 Binding Protein 1 (53BP1) protein complex. EXPAND1 is an uncharacterised protein with no ascribed function in vivo. Our preliminary results indicated that, like the tumor suppressor 53BP1, EXPAND1 relocalises to sites of DNA breaks in response to genotoxic stress, suggesting that EXPAND1 represents a novel DNA damage responsive element in the mammalian DNA damage response (DDR) pathway. Moreover, we have also confirmed the specific interaction between endogenous 53BP1 and EXPAND1 in vivo, illustrating the applicability of TAP in the identification and mapping of protein networks in vivo. WORKING HYPOTHESIS Given that 53BP1 has an established role in maintaining genome stability, that EXPAND1 is a component within the 53BP1 protein complex, and that EXPAND1 accumulates at DNA breaks, we hypothesise that EXPAND1 is a novel DNA damage responsive factor required for the protection of genome integrity. SPECIFIC AIMS: Specific Aim 1: Determine the functional relationship of EXPAND1 and 53BP1 Given that EXPAND1 is a component of the tumor suppressor 53BP1 protein complex, we will 1a) map the interacting domains required for the 53BP1-EXPAND1 interactions. Understanding of how 53BP1 and EXPAND1 interact will shed light into the molecular mechanisms that govern the spatial and temporal control of the protein complex formation, which likely play an instrumental role in the propagation of the DNA damage signal. Based on the knowledge that 53BP1 plays intimate roles in checkpoint control and DNA repair, we will 1b) test whether EXPAND1 is required for these 53BP1-dependent processes. It will be of significant interest to examine whether EXPAND1 is specifically involved in a subset of 53BP1 functions or whether it is an upstream regulator of 53BP1 function in the DDR pathway. These studies will allow us to functionally dissect the genetic bases that govern EXPAND1 function in the DNA damage response. Specific Aim 2: Delineate the domain and genetic requirements for EXPAND1 accumulation at DNA damage sites To test how EXPAND1 play a role in the DDR, we will 2a) examine the domain requirement for EXPAND1 recruitment to DNA damage sites. The recruitment and concentration of checkpoint and repair proteins to sites of DNA breaks, including the tumor suppressors BRCA1 and 53BP1, are essential for the proper execution of the DDR. In line with the importance for proper loading of DDR factors onto the damage-modified chromatin, patient mutations that abrogate BRCA1 accumulation at DNA breaks have previously been identified and characterised. Thus, knowledge into how EXPAND1 relocalises in response to genotoxic stress is one of the first step towards understanding the biology of EXPAND1 in the DNA damage response. The DDR pathway entails cascades of protein-protein interactions, governed by various post-translational modifications including protein phosphorylations and protein ubiquitylations, which are molecular switches that allows the timely activation of processes including cell cycle arrest, DNA repair and apoptosis. To identify factors important for EXPAND1 tethering at DNA damage sites, we will 2b) delineate the genetic requirements for EXPAND1 recruitment to sites of DNA damage. Since 53BP1 accumulation at DNA breaks requires the canonical DNA damage response pathway that involves the phosphorylation of the histone variant H2A.X, we will test where EXPAND1 fits in this established pathway. Understanding of how EXPAND1 is recruited to DNA breaks will help dissect the genetic factors that govern and control EXPAND1 function in the DNA damage response. Specific Aim 3: Identify factors required for EXPAND1 targeting at the chromatin Domain search using the EXPAND1 coding sequence revealed the presence of a conserved Pro-Trp-Trp-Pro (PWWP) motif. Recent evidence indicated that the PWWP motif targets its proteins via direct interaction with components of the chromatin ie. DNA and histones. Consistently, our preliminary results indicated that EXPAND1 stably associates with the chromatin. Given that the subcellular localisation of EXPAND1 at the chromatin likely constitute a key pre-requisite for its in vivo function, we will 3a) map the domain required for EXPAND1 targeting at the chromatin. In addition, to address how EXPAND1 associates with the chromatin, we will 3b) identify the components required for EXPAND1 association at the chromatin. Specific Aim 4: Identify EXPAND1-associated factors involved in the DDR pathway Several lines of evidence implicate an intricate protein network exists to allow the activation and coordination of various DNA damage-dependent cellular processes, of which constitute the DDR. Thus, we will 4a) identify EXPAND1-interacting proteins. Although exploratory in nature, the identification of EXPAND1-interacting proteins will provide additional hints into EXPAND1 function in vivo. In addition, these studies will also enable the discovery of novel components in the DDR pathway. As described from the above objectives, we hope to elucidate how EXPAND1 play a role in the maintenance of genome stability. Through the understanding of EXPAND1 functions, we will gain a better understanding of how the mammalian DDR pathway has evolved to protect genome integrity and counteract tumorigenesis.

List of Research Outputs

Huen M.S.Y. and Chen J., ATM creates a veil of transcriptional silence, CELL. 2010, 141: 924-6.

Huen M.S.Y. and Chen J., Assembly of checkpoint and repair machineries at DNA damage sites, TRENDS IN BIOCHEMICAL SCIENCES. 2010, 35(2): 101-8.

Huen M.S.Y., Sy S.M.H. and Chen J., BRCA1 and its toolbox for the maintenance of genome integrity, NATURE REVIEWS MOLECULAR CELL BIOLOGY . 2010, 11(2): 138-48.

Huen M.S.Y., Dissecting the Mammalian DNA Damage Response , College of Life Sciences, South China Agricultural University . 华南农业大学生命科学学院, 2010.

Huen M.S.Y., Dissecting the Mammalian DNA Damage Response, Chinese University of Hong Kong. 2009.

Huen M.S.Y., Huang J., Leung J.W.C., Sy S.M.H., Leung K.M., Ching Y.P., Tsao G.S.W. and Chen J., Regulation of Chromatin Architecture by the PWWP Domain-Containing DNA Damage-Responsive Factor EXPAND1/MUM1, MOLECULAR CELL. 2010, 37(6): 854-864.

Huen M.S.Y., Regulatory Ubiquitylation in the DNA Damage Response, 16th Hong Kong International Cancer Congress & 6th Annual Meeting Centre for Cancer Research . 2009.

Liu C., Wang Z., Huen M.S.Y., Lu L., Liu D. and Huang J., Cell death caused by single-stranded oligodeoxynucleotides mediated targeted genomic sequence modification, Oligonucleotides. 2009, 19(3): 281-286.

Santos M.A., Huen M.S.Y., Jankovic M., Chen H., Lopez-Contreras A., Klein I.A., Wong N., Barbancho J.L., Fernandez-Capetillo O., Nussenzweig M., Chen J. and Nussenzweig A., Class switching and meiotic defects in mice lacking the E3 ubiquitin ligase RNF8, JOURNAL OF EXPERIMENTAL MEDICINE. 2010, 207(5): 973-81.

Researcher : Hugon J

Project Title:	Society for Neuroscience 30th Annual Meeting Tau Phosphorylation during neuronal Apoptosis Induced by NMDA Receptor Blockade: an in Vivo Study
Investigator(s):	Hugon J
Department:	Anatomy
Source(s) of Funding:	URC/CRCG - Conference Grants for Teaching Staff
Start Date:	11/2000

Abstract:

N/A

Researcher : Huie MJ

List of Research Outputs

Chao J., Lau K.W., Huie M.J., Ho Y.S., Yu M.S., Lai S.W., Wang M., Yuen W.H., Lam W.H., Chan T.H. and Chang R.C.C., A pro-drug of the green tea polyphenol (-)-epigallocatechin-3-gallate (EGCG) prevents differentiated SH-SY5Y cells from toxicity induced by 6-hydroxydopamine, Neuroscience Letters. 2010, 469: 360-364.

Researcher : Hung CHL

List of Research Outputs

Cheung Y.T., Zhang N.Q., Hung C.H.L., Lai S.W., Yu M.S. and Chang R.C.C., Autophagy may protect neurons from low molecular weight beta-amyloid peptide-induced apoptosis, 5th International Symposium on Healthy Aging. 2010, Page 58.

Hung C.H.L., Cheung Y.T., Ho Y.S. and Chang R.C.C., Intracellular organelle collapse triggered by low molecular weight b-amyloid peptides, 5th International Symposium on Healthy Aging. 2010, Page 61.

Researcher : Hung HL

List of Research Outputs

Chang R.C.C., Zhang Q., Hung H.L., Cheung Y.T., Ho Y.S., Lai S.W. and Wuwongse S., Pathogenesis of Alzheimer's Disease, 5th International Symposium on Healthy Aging. 2010, Page 19.

Cheung Y.T., Zhang Q., Hung H.L., Lai S.W., Yu M.S., So K.F. and Chang R.C.C., Investigating the temporal transition of autophagy and apoptosis in neurons stressed by low molecular weight beta-amyloid peptide toxicity, 11th International Geneva/Springfield Symposium on Advances in Alzheimer Therapy, March 24-27, 2010 Geneva. 2010, 42.

Hung H.L., Ho Y.S. and Chang R.C.C., Modulation of mitochondrial calcium as a pharmacological target for Alzheimer's disease, Ageing Research Reviews. 2010, 9: 447-456.

Wuwongse S., Hung H.L., Law A.C.K. and Chang R.C.C., Corticosterone induced synaptic degeneration in depression and Alzheimer's disease, Collegium Internationale Neuro-Psychopharmacologicum (CINP) 2010 World Congress. 2010, P-09.

Researcher : Kwan PS

List of Research Outputs

Kwan P.S., Roles of Daxx in mitosis and prostate carcinogenesis. 2009, 77.

Researcher : Lai SW

List of Research Outputs

Chang R.C.C., Zhang Q., Hung H.L., Cheung Y.T., Ho Y.S., Lai S.W. and Wuwongse S., Pathogenesis of Alzheimer's Disease, 5th International Symposium on Healthy Aging. 2010, Page 19.

Chao J., Lau K.W., Huie M.J., Ho Y.S., Yu M.S., Lai S.W., Wang M., Yuen W.H., Lam W.H., Chan T.H. and Chang R.C.C., A pro-drug of the green tea polyphenol (-)-epigallocatechin-3-gallate (EGCG) prevents differentiated SH-SY5Y cells from toxicity induced by 6-hydroxydopamine, Neuroscience Letters. 2010, 469: 360-364.

Cheung Y.T., Zhang N.Q., Hung C.H.L., Lai S.W., Yu M.S. and Chang R.C.C., Autophagy may protect neurons from low molecular weight beta-amyloid peptide-induced apoptosis, 5th International Symposium on Healthy Aging. 2010, Page 58.

Cheung Y.T., Zhang Q., Hung H.L., Lai S.W., Yu M.S., So K.F. and Chang R.C.C., Investigating the temporal transition of autophagy and apoptosis in neurons stressed by low molecular weight beta-amyloid peptide toxicity, 11th International Geneva/Springfield Symposium on Advances in Alzheimer Therapy, March 24-27, 2010 Geneva. 2010, 42.

Researcher : Lai SW

List of Research Outputs

Chang R.C.C., Zhang Q., Hung H.L., Cheung Y.T., Ho Y.S., Lai S.W. and Wuwongse S., Pathogenesis of Alzheimer's Disease, 5th International Symposium on Healthy Aging. 2010, Page 19.

Researcher : Lam AKM

Project Title:	Investigating the role of Epac in the differentiation of mouse and human embryonic stem cells into insulin-producing cells
Investigator(s):	Lam AKM
Department:	Medical Faculty
Source(s) of Funding:	Research Centre of Heart, Brain, Hormone and Healthy Aging - General Award
Start Date:	09/2006

Abstract:

To determine the role of Epac on the expression of beta-cell specific markers in the differentiation of mouse and human embryonic stem cells into pancreatic beta-cells; to determine the effect of Epac knockout in the differentiation of mouse embryonic stem cells to pancreatic beta cells; to determine the survival and in vivo function of Epac transduced or Epac analogue treated hESC-derived insulin-producing cells.

Project Title:	Investigating the role of Epac in the differentiation of mouse and human embryonic stem cells into insulin-producing cells
Investigator(s):	Lam AKM, Chung SK, Lam KSL
Department:	Medical Faculty
Source(s) of Funding:	Small Project Funding
Start Date:	09/2006

Abstract:

In type 1 and late stage of type 2 diabetes, blood glucose level is dependent on the hormones of the pancreas, insulin, which is released from pancreatic beta cell. Insulin secretion from the beta cells is regulated positively and negatively by many intracellular signals generated by various factors, including nutrients, hormones and neurotransmitters. cAMP is thought to be a most critical intracellular signal in the mechanism of insulin secretion (1,2). Glucose is believed to act principally to stimulate mitochondrial ATP synthesis, leading to the closure of ATP-sensitive K channel, cell depolarization, calcium influx and exocytosis.GLP-1 is an insulinotropic hormone with blood glucose-lowering properties secreted by endocrine L cells of the intestinal tract. Binding of GLP-1 to the GLP-1 receptor stimulate the production of cAMP and the increase in intracellular Ca2+ for insulin secretion in pancreatic beta cells. Epac is a novel cAMP regulated guanine exchange factor for the Ras-like small GTPase Rap1 and Rap2 (3,4). It was shown that the GEF activity of Epac was strongly induced by cAMP besides protein kinase A. There are two isoforms of Epac, Epac1 and Epac2, in the mammalian cell. Both isoforms are expressed in pancreatic beta-cells (5) and is suggested to mediate the stimulatory actions of GLP-1 on Ca2+-dependent insulin secretion. Treatment with antisense oligonucleotide against Epac2 blocks the GLP-1-potentiated insulin secretion in the mouse pancreatic islets (6,7). Epac also acts as cAMP sensor, which specifically interacted with ATP-sensitive K+ channel (ATP sensor), Piccolo (Ca2+ sensor) and L-type voltage-dependent Ca2+ channels for insulin exocytosis (6,8). The Ca2+ release by GLP-1 agonist, exendin-4, is blocked by the overexpression of dominant negative Epac but increased by Epac selective analogue, 8-pCPT-2’-O-Me-cAMP (9). Therefore, by activating of Epac, GLP-1 sensitizes the beta cells to respond to the blood glucose level and stimulate insulin secretion. Therefore, it is hypothesized that the interaction of Epac and GLP-1 in insulin secretion may be relevant to the treatment of type 2 diabetes. In recent years, the potential use of mouse and human embryonic stem cells to generate insulin-producing cells in an attempt to treat type 1 and type 2 diabetes has received much attention (10-13). The differentiated insulin producing cells from mouse embryonic stem cells has been shown to reverse the hyperglycemia when transplanted into diabetic mice (14). However, the current issues for expression of insulin during in vitro beta-cell differentiation remain controversial since the amount of insulin produced by pure beta-cell population in the glucose dependent manner is considerably below that of native pancreatic islets. Epac is suggested to promote the beta-cell survival and mediate the regulation of beta-cell stimulus-secretion coupling. GLP-1 and cAMP analogue, which selectively activates Epac inhibited palmitate-mediated caspase-3 activation in a dose-dependent manner in beta-cell line RINm5F (15). Furthermore, Epac-specific analogue activated the PKA-dependent Erk1/2 signalling pathway and converts cAMP from a proliferative signal into differentiation signal in the neuronal cell line (16). Our preliminary data show that Epac1 and Epac2 are expressed as early in the undifferentiated stage of mouse embryonic stem cells (mESC). Moreover, the number of insulin positive cells from the differentiation of Epac1-/- mESC was significantly lower that that of wild type mESC. Therefore, it is proposed that Epac may be a growth and/or differentiation factor for the pancreatic beta-cells. We hypothesized that Epac plays an important role in the in vitro differentiation and proliferation of embryonic stem cells into beta-cells for the treatment of diabetes mellitus. The main objectives of this proposal are as follow: 1. To determine the role of Epac on the expression of beta-cell specific markers in the differentiation of mouse and human embryonic stem cells into pancreatic beta-cells 2. To determine the effect of Epac knockout in the differentiation of mouse embryonic stem cells to pancreatic beta cells 3. To determine the survival and in vivo function of Epac transduced or Epac analogue treated hESC-derived insulin-producing cells References: 1.Schuit, F. C., and Pipeleers, D. G. (1985) Endocrinology 117, 834-840 2.Pipeleers, D. G., Schuit, F. C., in't Veld, P. A., Maes, E., Hooghe-Peters, E. L., Van de Winkel, M., and Gepts, W. (1985) Endocrinology 117, 824-833 3.de Rooij, J., Zwartkruis, F. J., Verheijen, M. H., Cool, R. H., Nijman, S. M., Wittinghofer, A., and Bos, J. L. (1998) Nature 396, 474-477 4.Holz, G. G. (2004) Diabetes 53, 5-13. 5.Leech, C. A., Holz, G. G., Chepurny, O., and Habener, J. F. (2000) Biochem Biophys Res Commun 278, 44-47 6.Kashima, Y., Miki, T., Shibasaki, T., Ozaki, N., Miyazaki, M., Yano, H., and Seino, S. (2001) J Biol Chem 276, 46046-46053 7.Fujimoto, K., Shibasaki, T., Yokoi, N., Kashima, Y., Matsumoto, M., Sasaki, T., Tajima, N., Iwanaga, T., and Seino, S. (2002) J Biol Chem 277, 50497-50502 8.Shibasaki, T., Sunaga, Y., Fujimoto, K., Kashima, Y., and Seino, S. (2004) J Biol Chem 279, 7956-7961 9.Kang, G., Chepurny, O. G., Rindler, M. J., Collis, L., Chepurny, Z., Li, W. H., Harbeck, M., Roe, M. W., and Holz, G. G. (2005) J Physiol 566, 173-188 10.Lumelsky, N., Blondel, O., Laeng, P., Velasco, I., Ravin, R., and McKay, R. (2001) Science 292, 1389-1394 11.Blyszczuk, P., Asbrand, C., Rozzo, A., Kania, G., St-Onge, L., Rupnik, M., and Wobus, A. M. (2004) Int J Dev Biol 48, 1095-1104 12.Assady, S., Maor, G., Amit, M., Itskovitz-Eldor, J., Skorecki, K. L., and Tzukerman, M. (2001) Diabetes 50, 1691-1697 13.Segev, H., Fishman, B., Ziskind, A., Shulman, M., and Itskovitz-Eldor, J. (2004) Stem Cells 22, 265-274 14.Soria, B., Roche, E., Berna, G., Leon-Quinto, T., Reig, J. A., and Martin, F. (2000) Diabetes 49, 157-162 15.Kwon, G., Pappan, K. L., Marshall, C. A., Schaffer, J. E., and McDaniel, M. L. (2004) J Biol Chem 279, 8938-8945 16.Kiermayer, S., Biondi, R. M., Imig, J., Plotz, G., Haupenthal, J., Zeuzem, S., and Piiper, A. (2005) Mol Biol Cell 16, 5639-5648

List of Research Outputs

Yau T.O., Leung T.H.Y., Lam S.G.S., Cheung O.F., Tung K.K., Khong P.L., Lam A.K.M., Chung S.K. and Ng I.O.L., Deleted in liver cancer 2 (DLC2) was dispensable for development and its deficiency did not aggravate hepatocarcinogenesis., PLoS One. 2009, 4(8): e6566.

Researcher : Lau KW

List of Research Outputs

Chao J., Lau K.W., Huie M.J., Ho Y.S., Yu M.S., Lai S.W., Wang M., Yuen W.H., Lam W.H., Chan T.H. and Chang R.C.C., A pro-drug of the green tea polyphenol (-)-epigallocatechin-3-gallate (EGCG) prevents differentiated SH-SY5Y cells from toxicity induced by 6-hydroxydopamine, Neuroscience Letters. 2010, 469: 360-364.

Cheung Y.T., Lau K.W. and Chang R.C.C., What do we need to concern in using cell line for neurotoxicology research, differentiation or disturbance of intracellular signaling?, NeuroToxicology. 2009, 31: 164-166.

Lau K.W., Law A.C.K., Ip M.S.M. and Mak J.C.W., Involvement of Serotonin in Cigarette Smoke-Induced IL-8 Release in Airway Epithelial Cells, ATS 2010 International Conference, New Orleans, USA (May 14-19, 2010). 2010.

Researcher : Lau KW

List of Research Outputs

Researcher : Lau WM

Project Title:	Potential beneficial effect of Lycium barbarum polysaccharide on sociosexual behaviour of rats
Investigator(s):	Lau WM, So KF
Department:	Anatomy
Source(s) of Funding:	Small Project Funding
Start Date:	01/2010

Abstract:

For human beings, sexuality is an union of mind and body (1). Sexual intimacy is an essential mean of communication between couples and partners, which in turns as an important determinant of quality of life. Various medical conditions, both physical and psychological, could lead to sexual dysfunction. Examples are cardiovascular disease, multiple sclerosis, spinal cord injury or major depressive disorder (2, 3). Treatment of sexual dysfunction would not only improves the quality of life of patients, but also makes the treatment regimens to be more bearable and may increase compliance to treatment (1) through intimate interaction with their partners. A male normal sexual cycle could be divided into five events: 1. libido/desire, 2. erection, 3. orgasm, 4. ejaculation and 5. detumescence. These stages occur in the defined sequence in a successful sexual intercourse and any disturbance in the cycle is known as male sexual dysfunction (4). It is commented that current treatment options for male sexual dysfunction are expensive and not readily available (Yakubu 07), which urges search for natural aphrodisiac supplement which could alleviate male sexual dysfunction. It is expected that the natural remedies exert less side effect, are readily available and less expensive than the current options (5). Fruit of Lycium barbarum is a traditional Chinese medicine which has been used for thousands of years (6). The medical beneficial effects of Lycium barbarum on chronic conditions are diversive, which includes hyperlipidemia, diabetes, hepatitis and male infertility (6). The pro-fertility effect of Lycium barbarum was described by Chinese herbalist Li Shizhen in the XVI century and it is included in most Chinese medicines for male infertility (7). In vitro study showed that thermal damage mouse seminiferous epithelium in testis could be minimized by treatment of Lysium barbarum polysaccharide (LBP) (7), which is probably due to the antioxidant action of LBP. Similar result was also observed in vivo: heat exposure to 43 ˚C caused rat testicular tissue damage, which could be prevented by LBP treatment (6). Furthermore, LBP treatment improved copulatory behaviour of hemicastrated male rats by decreasing mount latency and increased serum level of testosterone. In a clinical study which involved oral consumption of Lycium barbarum juice for 14 days, it was verbally reported by several subjects that the juice consumption is associated with increase in sexual activity and ability (8). Collectively, these results suggest a potential effect of Lycium barbarum on male sexual dysfunction and infertility. Stress and depression are established to be a potential cause of male sexual dysfunction, for instance (9, 10). It is unknown yet whether LBP has beneficial effect on sexual dysfunction caused by stress. In this proposed study we aim at elucidating whether 1. Chronic LBP treatment have beneficial effect on male sexual behaviour and 2. chronic LBP treatment could reverse the inhibitory effect on sexual behaviour caused by stress. It is our hypothesis that Lycium barbarum polysaccharide (LBP), which was suggested to promote male fertility, could improve male sexual performance in a stress animal model. Thus the aims of the studies are: 1. To determine whether chronic LBP treatment increase male sexual performance; 2. To test whether inhibited male sexual performance, caused by chronic high dose corticosterone treatment, could be minimized by LBP treatment; 3. To test whether serum sexual hormones, testosterone and luteinizing hormones, are affected by corticosterone and LBP treatment, and whether an association between these hormones and sexual performance could be found.

Project Title:	ANS/AuPS 2010 - The 30th Annual Meeting of the Australian Neuroscience Society Lycium Barbarum (Wolfberry) polysaccharide facilitates ejaculatory behavior in male rats
Investigator(s):	Lau WM
Department:	Anatomy
Source(s) of Funding:	URC/CRCG - Conference Grants for Teaching Staff
Start Date:	01/2010
Completion Date:	02/2010

Abstract:

N/A

List of Research Outputs

Lau W.M., Yau S.Y., Lee T.M.C., Ching Y.P., Tang S.W. and So K.F., Corticosterone suppresses dendritic maturation of immature neurons in hippocampus, which is counteracted by antidepressant treatment, Neuroscience Bulletin. 2009, 25(1): 450.

Lau W.M., Yau S.Y., Lee C.D., Chang R.C.C. and So K.F., Effect of Lycium Barbarum (Wolfberry) polysaccharide on sexual behavior of male rats, Collegium Internationale Neuro-Psychopharmacologicum (CINP) 2010 World Congress. 2010, P-02.

Lau W.M., Yau S.Y., Lee T.M.C., Ching Y.P., Tang S.W. and So K.F., Effect of corticosterone and paroxetine on masculline mating behavior: Possible involvement of neurogenesis, Pan Pacific Symposium on Stem Cells Research, April 16-19, 2010, Taiwan. 2010, 77.

Lau W.M., Yau S.Y., Lee C.D., Chang R.C.C. and So K.F., Lycium barbarum (wolfberry) polysaccharide facilitates ejaculatory behaviour in male rats. , Annual Meeting of the Australian Neuroscience Society. 2010.

Lau W.M., Yau S.Y., Lee T.M.C., Ching Y.P., Tang S.W. and So K.F., Possible involvement of neurogenesis in male rat mating behavior, Cell Transplantation. 2010, 19(3): 347.

Wang H., Lau W.M., Yau S.Y., Li S.Y., Leung N.E.L.S.O.N., Wang N.I.N.G.L.I., Tang S.W., Lee T.M.C. and So K.F., The roles of paroxetine and corticosterone on adult mammalian retinal ciliary body cell proliferation, The Chinese Medical Journal. 2010, 123: 1305-1310.

Wang H., Lau W.M., Yau S.Y., Li S.Y., Leung N., Tang S.W., Lee T.M.C. and So K.F., Roles of paroxetine and corticosterone on adult mammalian ciliary body cell proliferation. , Chinese Medical Journal. 2010, 123: 1305-1310.

Wang H., Lau W.M., Yau S.Y., Li S.Y., Leung N., Wang N.L., Tang S.W., Lee T.M.C. and So K.F., Roles of paroxetine and corticosterone on adult mammalian ciliary body cell proliferation, Chinese Medical Journal. 2010, 123: 1305-1310.

Yau S.Y., Lau W.M., Tong J., Ching Y.P., Lee T.M.C. and So K.F., Hippocampal cell proliferation and dendritic enrichment is essential for beneficial effects of exercise on stressed animal model, Hellenic Society for Neuroscience, 23rd Annual Meeting, September 13-14, 2009, Greece.. 2009, 78-79.

Yau S.Y., Lau W.M., Tong J., Wong R., Ching Y.P., Qiu G., Tang S.W., Lee T.M.C. and So K.F., Hippocampal cytogenesis and dendritic plasticity support running-enhanced memory and depression behavior, Proceedings of the International Anatomical Sciences and Cell Biology Conference, May 26-29, 2010. 37.

Yau S.Y., Lau W.M., Tong J., Wong R., Ching Y.P., Qiu G., Tang S.W., Lee T.M.C. and So K.F., Hippocampal cytogenesis and dendritic plasticity support running-enhanced memory and depression behaviour in stressed rat, The 4th Beijing International Forum on Rehabilitation, Oct. 28-30, 2009. 6-7.

Yau S.Y., Lau W.M., Tong J.B., Ching Y.P., Qiu G., Lee T.M.C. and So K.F., Hippocampal neurogenesis and dentritic enrichment are involved in neuroprotective of physical exercise on stress., Neuroscience Bulletin. . 2009, 25 Supp 1: 379-380.

Zhang E., Yau S.Y., Lau W.M., So K.F. and Chang R.C.C., Anti-depressive effects of Lycium Barbarum in a rat depression model, Collegium Internationale Neuro-Psychopharmacologicum (CINP) 2010 World Congress. 2010, P-09.

Researcher : Lau WM

List of Research Outputs

Lau W.M., Yau S.Y., Lee T.M.C., Ching Y.P., Tang S.W. and So K.F., Possible involvement of neurogenesis in male rat mating behavior, Cell Transplantation. 2010, 19(3): 347.

Yau S.Y., Lau W.M., Tong J., Wong R., Ching Y.P., Qiu G., Tang S.W., Lee T.M.C. and So K.F., Hippocampal cytogenesis and dendritic plasticity support running-enhanced memory and depression behaviour in stressed rat, The 4th Beijing International Forum on Rehabilitation, Oct. 28-30, 2009. 6-7.

Researcher : Lee CW

List of Research Outputs

Lee C.W. and Ching Y.P., Identification of downstream targets of LKB1, The 32th annual meeting of the molecular biology society of Japan. 2009.

Lee C.W. and Ching Y.P., The role and Regulation of SirT1 throungh the LKB1-AMPK Pathway in Hepatocellular carcinoma, 16th Hong Kong International Cancer Congress. 2009.

Lee C.W. and Ching Y.P., Underexpression of LKB1 in hepatcellular carcinoma, The LKB1-AMPK pathway from Basic science to clinical applications . 2010.

Researcher : Lee DTW

List of Research Outputs

Luk S.U., Yap W.N., Chiu Y.T., Lee D.T.W., Ma S.K.Y., Lee K.W., Vasireddy R.S., Wong Y.C., Ching Y.P., Nelson C.O.L.L.E.E.N., Yap Y.L. and Ling M.T., Gamma-tocotrienol as an effective agent in targeting prostate cancer stem cell-like population, International Journal of Cancer. 2010.

Researcher : Lee LS

List of Research Outputs

Lee L.S., Characterization of arsenic transformed rat lung epithelial cells (TLECs) by biochemical and proteomic approaches. 2009, 163 pages.

Researcher : Leung JWC

List of Research Outputs

Mi X., Chiu K., Van G., Leung J.W.C., Lo A.C.Y., Chung S.K., Chang R.C.C. and So K.F., The effect of lycium barbarum (wolfberry) on the expression of endothelin-1 and its receptors in an ocular hypertension model of glaucoma, 5th International Symposium on Healthy Aging. 2010, Page 55.

Yeung P.K.K., Lo A.C.Y., Leung J.W.C., Chung S.S.M. and Chung S.K., Targeted overexpression of endothelin-1 in astrocytes leads to more severe cytotoxic brain edema and higher mortality, Journal of Cerebral Blood Flow & Metabolism. 2009, 29: 1891-1902.

Researcher : Leung KM

List of Research Outputs

Huen M.S.Y., Huang J., Leung J.W.C., Sy S.M.H., Leung K.M., Ching Y.P., Tsao G.S.W. and Chen J., Regulation of Chromatin Architecture by the PWWP Domain-Containing DNA Damage-Responsive Factor EXPAND1/MUM1, MOLECULAR CELL. 2010, 37(6): 854-864.

Researcher : Leung TM

List of Research Outputs

Tipoe G.L., Leung T.M., Liong E.C., Lau T.Y.H., Fung M.L. and Nanji A.A., Epigallocatechin-3-gallate (EGCG) reduces liver inflammation, oxidative stress and fibrosis in carbon tetrachloride (CCl₄)-induced liver injury in mice, Toxicology. 2010, 273: 45-52.

Tipoe G.L., Ho M.C.T., Liong E.C., Leung T.M., Lau T.Y.H., Fung M.L. and Nanji A.A., Voluntary oral feeding of rats not requiring a very high fat diet is a clinical relevant model of non-alcoholic fatty liver disease (NAFLD), Histology and Histopathology. 2009, 24(9): 1161-1169.

Researcher : Li B

List of Research Outputs

Li B., Id1-induced activation of P13K/AKT/NFkb pathway: mechanisms and significance in esophageal cancer. 2009, 183 pages.

Li B., Li Y.Y., Tsao G.S.W. and Cheung A., Targeting NF-kB signaling pathway suppresses tumor growth, angiogenesis, and metastasis of human esophageal cancer, Molecular Cancer Therapeutics. 2009, 8(9): 2635-2644.

Researcher : Li H

List of Research Outputs

Hui X., Li H., Zhou Z., Lam K.S.L., Xiao Y., Wu D., Ding K., Wang Y., Vanhoutte P.M.G.R. and Xu A., Adipocyte fatty acid-binding protein modulates inflammatory responses in macrophages through a positive feedback loop involving c-Jun NH2-terminal kinases and activator protein-1, J Biol Chem. 2010, 285(14): 10273-80.

Li H., Lam A.K.Y., Xu A., Lam K.S.L. and Chung S.K., High dosage of Exendin-4 increased early insulin secretion in differentiated beta cells from mouse embryonic stem cells, Acta Pharmacol Sin. 2010, 31(5): 570-7.

Researcher : Li J

List of Research Outputs

Li J., Gao G.D. and Yuan T., Cell based vaccination using transplantation of iPSC-derived memory B cells, Vaccine. 2009, 27: 5728-5729.

Researcher : Li RHW

List of Research Outputs

Li R.H.W., Liao S., Chiu C.N., Tam W.W., Ho J.C.M., Ng E.H.Y., Ho P.C., Yeung W.S.B., Tang F. and O W.S., Expression of adrenomedullin in human oviduct, its regulaton by the hormonal cycle and contact with spermatozoa, and its effect on ciliary beat frequency of the oviductal epithelium, Journal of Clinical Endocrinology and Metabolism. 2010, 95(9): E18-E25.

Researcher : Li YY

List of Research Outputs

Li B., Li Y.Y., Tsao G.S.W. and Cheung A., Targeting NF-kB signaling pathway suppresses tumor growth, angiogenesis, and metastasis of human esophageal cancer, Molecular Cancer Therapeutics. 2009, 8(9): 2635-2644.

Researcher : Liang Y

List of Research Outputs

Ellis-Behnke R.G., Liang Y., Cheung W.H. and Tay D.K.C., Controlling The Growth And Differentiation Of Cells With Physical Interaction, Nanobiotech 2009.

Ellis-Behnke R.G., Liang Y., Guo J., Tay D.K.C., Schneider G.E., Teather L.A., Wu W. and So K.F., Forever young: how to control the elongation, differentiation and proliferation of cells using nanotechnology, Cell Transplantation. 2009.

Ellis-Behnke R.G., Cheung W.H., Liang Y. and Liang Y., Nanomedicine and nanotechnology applied to neurosciences, 4th International Multidisciplinary Congress on Intensive and Critical Care Medicine. 2009.

Ellis-Behnke R.G., Cheung W.H., Liang Y. and Tay D.K.C., Nanoscale Image Contrast Agents To Enhance The Visualization Of Regenerating Cns Axons, Presidential Symposium on Nanotechnology at the 51st Meeting of the American Society for Therapeutic Radiology and Oncology (ASTRO). 2009.

Ellis-Behnke R.G., Liang Y., Cheung W.H., So K.F., Wu W. and Tay D.K.C., Redefining tissue engineering for nanomedicine: Visualizing the progress of regenerating axons in the mammalian visual system after complete transection and treatment with self-assembling nanomaterial, 6th Annual World Congress for Brain Mapping and Image Guided Therapy, Harvard Medical School, Boston MA. 2009.

Ellis-Behnke R.G., Cheung W.H., Tay D.K.C., Liang Y., Lui Kau K.W.F., Schneider G.E. and So K.F., The control of stem cells in the brain and spinal cord by extracellular nanomatrix system, Society for Neuroscience, Chicago. 2009.

Ellis-Behnke R.G., Liang Y., Cheung S.W.H., So K.F. and Tay D.K.C., Using a self-assembling nanopeptide to achieve ocular hemostasis without causing clotting or secondary inflammation, ARVO 2010. Program No. 427, Poster No. D1131.

Ellis-Behnke R.G., Liang Y., Cheung W.H. and Tay D.K.C., Using nanotechnology to control the elongation, differentiation and proliferation of cells, 16th Annual Optic Nerve Rescue and Restoration Think Tank. 2009.

So K.F., Liang Y., Tay D.K.C. and Ellis-Behnke R.G., Nanomedicine for CNS regeneration and instant hemostasis, WACBE World Congress on Bioengineering 2009, July 26-26, 2009, Hong Kong. 2009, 4.

Yuan T., Liang Y., Tay D.K.C., So K.F. and Ellis-Behnke R.G., Olfactory tract transection enhances adult neurogenesis in piriform cortex, 22nd Biennial Meeting of the International Society of Neurochemistry, Busan Korea. 2009.

Researcher : Liao S

List of Research Outputs

Chiu C.N., Liao S., Lam K.W., Tang F., Ho J.C.M., Ho P.C., O W.S., Yao Q.Y. and Yeung W.S.B., Adrenomedullin regulates sperm motility and oviductal ciliary beat via cyclic adenosine 5'-monophosphate/protein kinase A and nitric oxide, Endocrinology. 2010, 151(7): 3336-3347.

Li R.H.W., Liao S., Chiu C.N., Tam W.W., Ho J.C.M., Ng E.H.Y., Ho P.C., Yeung W.S.B., Tang F. and O W.S., Expression of adrenomedullin in human oviduct, its regulaton by the hormonal cycle and contact with spermatozoa, and its effect on ciliary beat frequency of the oviductal epithelium, Journal of Clinical Endocrinology and Metabolism. 2010, 95(9): E18-E25.

O W.S., Liao S., Sun J.Z., Ho J.C.M., Chiu C.N., Ng E.H.Y., Yeung W.S.B., Li R.H.W. and Tang F., Adrenomedullin and oviduct function in human and rats, Biology of Reproduction. 2009, 81: 99.

Researcher : Lin B

Project Title:	Remodeling of retinal cone bipolar cells in mouse models of rd
Investigator(s):	Lin B
Department:	Anatomy
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	01/2010

Abstract:

The general experimental approach - using both an adeno-associated virus (AAV) vector and a transgenic mouse that expresses GFP in the population of one type of cone bipolar cells to assess the cone bipolar cell response in mouse models of retinitis pigmentosa - is met with generally high enthusiasm, and remains unchanged. The work proposed here starts from the hypothesis that photoreceptors are directly involved in the postnatal maturation of cone retinal circuitry. Retinal cone bipolar cells, the essential backbone of the cone pathways, constitute a very large population of the second order neurons that receive inputs from photoreceptors in the outer retina and synapse onto ganglion cells and amacrine cells in the inner retina. When photoreceptors die, bipolar cells are left without their major source of input. Due to a lack of specific molecular markers and technical inaccessibility to the inner retinal neurons, we know relatively little about the morphology and light response properties of the cone bipolar cells in disease conditions and during aging, even though previous efforts have been made by other groups. To fill this significant gap in our knowledge, we will investigate the morphlogical and physiological properties of cone bipolar cells in macular degeneration and retinitis pigmentosa using a combination of confocal microscopy and patch-clamp recordings. The entirety of cone bipolar cells will be visualized through the expression of green fluorescent protein (GFP), following transduction with an adeno-associated virus (AAV) vector. This will make it possible to track anatomical changes during retinal degeneration. Specific aim 1: Learn the influence of loss of photoreceptors on the survival of cone bipolar cells in mouse models of retinal degeneration. Hypothesis: Photoreceptor afferent activity plays an important role in the postnatal maturation of cone retinal circuitry; cell loss in RP directly leads to the structural alteration of cone bipolar cells. Individual cone bipolar cells respond to the loss of photoreceptors by retracting processes and/or hyperplasy. Our second goal is to directly observe responses to pathology on the single-cell level in the cone bipolar cells. We plan to establish a mouse line in which a transgenic mouse strain with GFP-labeled one identified subtype of cone bipolar cells will be backcrossed with the rd mouse line that allows us to directly observe pathological changes of cone bipolar cells in both a short and a long-term model of retinal degeneration. Specific aim 2: Learn the time course and spread of the cone bipolar cell death in population of one subtype of cone bipolar cells in mouse models of retinal degeneration. Hypothesis: The alterations in shape and number of cone bipolar cells coincide with that of photoreceptor loss. The degeneration of cone bipolar cells follows the temporal and topographical degenerative patterns of photoreceptors: cells die first in the central retina, followed by those in the peripheral retina. Specific aim 3: Evaluate the initial response of individual cone bipolar cells to the loss of photoreceptor and examine whether the axons and dendrites of the cone bipolar cells develop normally. Hypothesis: The precise earliest onset of remodeling in the rd model is influenced by different initial defects in the various models. However, early photoreceptor afferent loss can lead to immature inner retinal connectivity and cell migration.

Project Title:	17th Annual Conference of the American Society for Neural Therapy & Repair Restoration of visual function by ectopic expression of melanopsin in rd mice
Investigator(s):	Lin B
Department:	Anatomy
Source(s) of Funding:	URC/CRCG - Conference Grants for Teaching Staff
Start Date:	04/2010

Abstract:

N/A

Researcher : Ling MT

Project Title:	The regulation and role of Id-1 in prostate cancer progression
Investigator(s):	Ling MT, Wong YC, Wang X
Department:	Anatomy
Source(s) of Funding:	Small Project Funding
Start Date:	09/2005

Abstract:

Background: Prostate cancer remains the most commonly diagnosed cancer in Western countries and recent reports indicated that the incidence and mortality rate of prostate cancer are rising significantly in Asian countries including Hong Kong. Nearly all the patients diagnosed with advanced stage prostate cancer will be treated with hormone ablation therapy, but most, if not all of them will inevitably progress to an androgen independent stage after a period of 2-3 years. The failure of the treatment is mainly due to the lost of dependency on androgen for the survival and proliferation of the cancer cells. Unfortunately, prostate cancer is relatively resistant to the chemotherapeutic drugs commonly used in the treatment of other cancers, making the disease virtually incurable at this stage. Therefore, to stop or at least delay the development of androgen independency could be the best way to improve the survival of prostate cancer patients. While the molecular events during the progression of prostate cancer have been studied intensively, the exact mechanism for the development of androgen independent disease is still unclear. Key issues: In the past 5 years, I have been studying the role of Id-1, which encodes an inhibitor of differentiation, in the development and progression of prostate cancer. We have recently shown that the Id-1 gene plays an important role in the development of androgen independent prostate cancer cell growth in tissue culture models [Ling et al., Carcinogenesis, 25:517, 2004]. We have demonstrated that Id-1 expression in prostate cancer cells is essential for the survival [Ling et al., Oncogene, 22:4498, 2003] and proliferation of the cells [Ling et al., Oncogene, 21:8498, 2002]. In prostate cancer cell lines as well as xenograft that grow independent of androgen, we have been able to detect very high level of Id-1 expression [Ling et al., Carcinogenesis, 25:517, 2004]. More interestingly, we have shown that over-expression of Id-1 in an androgen dependent prostate cancer cell line promotes the development of the androgen independent phenotype [Ling et al., Carcinogenesis, 25:517, 2004] i.e. androgen independent PSA expression and reduction of androgen responsiveness. These findings suggested that upregualtion of Id-1 is involved in the development of androgen independent prostate cancer. Purpose of the proposed project: The long-term goal of this proposal is to elucidate the molecular mechanism responsible for the upregulation of Id-1 during the progression of prostate cancer to the androgen independent stage and eventually facilitate the development of new therapeutic strategies against this disease. Hypothesis: The major hypothesis of this proposal is that expression of Id-1 in prostate cancer cells is negatively regulated by the androgen signaling pathway. This hypothesis is based on the following findings. Firstly, we found that androgen dependent prostate cancer cells LNCaP expressed very low level of Id-1 when cultured with fetal calf serum (FCS) [Ouyang et al, Carcinogenesis, 23:721, 2002], but the level of Id-1 increase sharply when steroids (including androgen) were removed from the FCS (unpublished data). Secondly, we have recently showed in human prostate cancer xenograft model that Id-1 expression was significantly upregulated in human prostate cancers soon after castration of the host [Ling et al., Carcinogenesis, in press, 2005]. Finally, the TGF-beta/Smad signaling pathway has been implicated as the major pathway controlling the transcription of the Id-1 gene [Kang et al., Mol Cell, 11:915, 2003]. Recently, Smad protein has been shown to be the coregulator of the androgen receptor (AR) signaling which enhances the androgen mediated PSA gene transcription [Kang et al., Proc. Natl. Acad. Sci.U.S.A, 98:3018, 2001]. Therefore, it was believed that AR and TGF-beta/Smad signaling pathway may regulate a number of their target genes synergistically. Based on these observations, the main focus of the proposed experiments will be on studying how androgen regulates the expression of Id-1 in prostate cancer cells and the significance of this regulation in the development of androgen independent prostate cancer. There are three specific aims in this study: 1. To determine the effect of androgen on the in vitro expression of Id-1 in prostate cancer cells. 2. To elucidate the signaling pathway involved in the regulation of Id-1 expression by androgen in prostate cancer cells. 3. To test the effect of Id-1 inactivation on the inhibition of prostate cancer progression.

Project Title:	The role of EMI1 in prostate carcinogenesis
Investigator(s):	Ling MT, Wang X
Department:	Anatomy
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	02/2007

Abstract:

Background: Prostate cancer is currently the most commonly diagnosed male cancer in Western countries and recent statistic data suggests that the incidence is increasing in Asian countries, including Hong Kong [1]. When presented at early stage where the tumor is still localized, prostate cancer can be treated effectively with surgical or radio-prostatectomy. However, when the cancer reached the metastatic stage, the only frontline treatment available is chemical or surgical castration, which normally results in rapid relief of symptoms. Unfortunately, more than 70% of the patients will suffer again from the disease due to the development of hormone refractory stage[1]. Currently, there is no effective second line treatment available that can significantly enhance the overall survival of the prostate cancer patients once they reached that stage. Therefore, it is important to identify a better prognostic marker as well as to develope an alternative therapeutic strategy against the disease. Key issues: 1. EMI1 is a cell cycle regulatory protein which promotes the S-phase entry of the cell cycle. Previously, EMI1 expression has been shown to be upregulated in several types of tumor, including breast, ovary and colon[2]. Meanwhile, ectopic expression of EMI1 has recently been shown to induced tetraploidy and genomic instability[3], which are the hallmarks of cancer cells, suggesting that EMI1 may play role in cancer development. In addition, EMI1 overexpression has also been demonstrated to be associated strongly with ER negative breast tumors and poor clinical outcome of breast cancer patients[4], suggesting that EMI1 may have function in tumor progression. However, the role of EMI1 in prostate cancer is so far unclear. 2. Recently, by examining the protein level of EMI1 in a series of prostate epithelial cell lines, we found that EMI1 was significantly upregulated in all the cancer cell lines that we tested, and the level was highest in the androgen independent prostate cancer cells. From limited archival materials examined, EMI1 was most highly expressed in AI prostate cancer tissue. These results suggest that EMI1 may play important roles in the development as well as the progression of prostate cancer. Hypothesis: EMI1 may play a promoting role in prostate carcinogensis and may be a novel prognostic marker as well as therapeutic target against prostate cancer. Objectives 1. To examine EMI1 expression in prostate cancer tissues. 2. To examine if EMI1 over-expression would promote the tumorigenesis of the prostate epithelial cells. 3. To test the inhibitory effect of EMI1 knockdown on prostate cancer development. References 1. Krongrad,A., Lai,S. and Vidal,E.M. The significance of changing trends in prostate cancer incidence and mortality, Semin.Urol.Oncol., 16: 30-34, 1998. 2. Hsu,J.Y., Reimann,J.D., Sorensen,C.S., Lukas,J. and Jackson,P.K. E2F-dependent accumulation of hEmi1 regulates S phase entry by inhibiting APC(Cdh1), Nat.Cell Biol., 4: 358-366, 2002. 3. Lehman,N.L., Verschuren,E.W., Hsu,J.Y., Cherry,A.M. and Jackson,P.K. Overexpression of the anaphase promoting complex/cyclosome inhibitor Emi1 leads to tetraploidy and genomic instability of p53-deficient cells, Cell Cycle, 5: 1569-1573, 2006. 4. van,'., V, Dai,H., van,d., V, He,Y.D., Hart,A.A., Mao,M., Peterse,H.L., van der,K.K., Marton,M.J., Witteveen,A.T., Schreiber,G.J., Kerkhoven,R.M., Roberts,C., Linsley,P.S., Bernards,R. and Friend,S.H. Gene expression profiling predicts clinical outcome of breast cancer, Nature, 415: 530-536, 2002.

Project Title:	The role of Daxx in chromosome instability and prostate carcinogenesis
Investigator(s):	Ling MT, Wong YC
Department:	Anatomy
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	06/2008

Abstract:

Prostate cancer is currently the most commonly diagnosed male cancer in Western countries and recent statistic data suggests that the incidence is increasing in Asian countries, including Hong Kong (1). When presented at early stage where the tumor is still localized, prostate cancer can be treated effectively with surgical or radio-prostatectomy. However, when the cancer reached the metastatic stage, the only frontline treatment available is chemical or surgical castration, which normally results in rapid relief of symptoms. Unfortunately, more than 70% of the patients will suffer again from the disease due to the development of hormone refractory stage(1). Currently, there is no effective second line treatment available that can significantly enhance the overall survival of the prostate cancer patients once they reached that stage. Therefore, it is important to understand the mechanism responsible for prostate carcinogenesis as well as to identify a better prognostic marker for prostate cancer patients. Key issues 1. Similar to other cancers, chromosome instability is frequently observed in prostate cancer cells and is believed to contribute to the activation or inactivation of oncogenes and tumor suppressor genes respectively (2). During mitosis, proper segregation of the duplicated chromosomes is maintained by the mitotic checkpoint which regulate the activities of the anaphase promoting complex (APC) (3). Previous studies demonstrated that a hyper or hypo sensitive checkpoint may lead to missegregation of chromosome leading to chromosome instability (4;5). However, the mechanism responsible for chromosome instability and its linkage to prostate cancer predisposition is still unclear. 2. We have recently identified a novel mitotic checkpoint protein called Daxx which physically interact with one of the APC coactivator cdc20. We found that Daxx can inhibit APC activities and delay mitotic progression. Meanwhile, using prostate cancer cell lines and a limited number of prostate cancer tissues, we demonstrated that Daxx was significantly upregulated in prostate cancer cells. Our findings support that Daxx may play roles in mitosis through regulation of the mitotic checkpoint and deregulation of Daxx expression may associated with chromosome instability. Hypothesis: Daxx may play a promoting role in prostate carcinogensis and may be a novel prognostic marker. Objectives 1. To examine Daxx expression in prostate cancer tissues. 2. To investigate the function of Daxx in mitotic progression and chromosome segregation. 3. To examine if Daxx over-expression would promote chromosome instability and tumorigenesis of the prostate epithelial cells.

Project Title:	Effect of Tocotrienol in the inhibition of hormone refractory prostate cancer
Investigator(s):	Ling MT, Wong YC
Department:	Anatomy
Source(s) of Funding:	Seed Funding Programme for Applied Research
Start Date:	08/2008

Abstract:

Background: Prostate cancer is the most common cancer diagnosed in man living in Western countries and its incidence in Asian countries increased sharply over the past decade (1). When presented at early stage where the tumor is still localized, the disease can be treated with prostatectomy. However, due to the slow growing nature of the prostate cancer cells, patients are usually presented at advanced stage and surgery is no longer feasible due to the development of metastasis. These patients will normally be treated with androgen ablation therapy which aims at blocking the androgen stimulation on the prostate cancer cells. The treatment will usually results in rapid regression of the tumor due to the androgen dependent nature of prostate epithelial cells. However, due to mechanism which is currently unclear, the tumor will re-grow in the absence of androgenic stimulation to become androgen independent prostate cancer (AIPC) and the patients will inevitably suffer again from the disease (2). Currently, there is no effective treatment available against the AIPC. As a result, most of the prostate cancer patients will die from this disease. Although the reason for the failure in androgen ablation therapy is still unclear, it is suggested that a small population of AIPC cells may already exist within the tumor before the therapy (3;4). These AIPC cells are believed to be the prostate cancer stem cells which may be responsible for the development of AIPC after androgen ablation therapy (3;4). This hypothesis was supported by the fact that prostate cancer stem cells isolated from cell lines and xenograft models are negative for AR expression (5;6). These cells have high potential of self-renewal and are able to survive in the absence of androgen due to their androgen independent (AI) characteristic (5;7). Interestingly, these stem cells were found to express AR after undergoing cellular differentiation (5), indicating that they can become androgen dependent prostate cancer cells under appropriate condition. These findings support that this small population of AIPC cells may represent the residual cancer cells which account for tumor recurrence after androgen ablation therapy. Therefore, targeting of this residual population immediately after androgen ablation therapy may significantly improve the treatment outcome of the patients. Unfortunately, only very few studies, if any, tried to use adjunctive therapy with androgen ablation for the treatment of prostate cancer. This may be due to the fact that residual tumors after androgen ablation therapy are usually too small to be recognizable and currently there is no marker available to identify or monitor them, making it impossible to determine the effectiveness of the adjunctive therapy. Therefore, most of the previous studies focus mainly on targeting the AIPC that developed after androgen ablation therapy. Since prostate cancer cells, especially those at AI stage, are highly resistant to the commonly used chemotherapeutic drugs, a significant improvement in the treatment outcome has so far highly unsatisfactory (8). Until recently, the only chemotherapeutic drug that shows an improvement in survival of patients is Docetaxel, which can only extend the overall survival for 2½ months (9), but is associated with significant side effects. Therefore, an alternative treatment strategy is urgently needed for advanced stage prostate cancer patients. Recently, we have demonstrated that the two compounds S-allyl-cysteine (SAC) and S-allyl-mercaptocysteine (SAMC) have anti-cancer effect against AIPC (10). SAC and SAMC are the major organosulfur compounds found in aged-garlic. In our recent studies, we demonstrated in an orthotopic prostate xenograft model that daily treatment of SAMC can significantly inhibit tumor growth and at the same time suppress both circulating tumor cell and tumor metastasis (11). More importantly, detailed toxicity study revealed that daily SAMC treatment does not impose any side effect on the animals (10). These results support that natural product like garlic extracts may be an effective and safe anti-cancer agent against AIPC. In addition to garlic extract, recent study demonstrated that Tocotrienols extracted from palm oil may selectively inhibit the proliferation of prostate cancer cells. Tocotrienols are derivatives of vitamin E and are found mainly in palm oil. It was found to specifically induced apoptosis in both the androgen dependent and independent prostate cancer cells but not in non-tumorigenic prostate epithelial cells (12). Meanwhile, no side effect can be observed after long term intake of Tocotrienol extract (13), suggesting that it may be used as a safe anti-cancer treatment for advanced stage prostate cancer. Therefore, in this study, we propose that Tocotrienol may be used as a novel adjunctive therapy with androgen ablation for improving the survival of advanced stage prostate cancer patients. This proposal is divided into two objectives: Objective #1. To test the in vivo effect of Tocotrienol on androgen independent prostate cancer xenograft. Since Tocotrienol is effective in targeting AIPC cells in vitro, we are interested in testing its in vivo anti-cancer effect using an AIPC xenograft model. Objective #2. To examine the synergistic effect of Tocotrienol and androgen ablation therapy on inhibition of prostate cancer progression. After androgen ablation therapy, residual tumor cells with androgen independent characteristic will always present which contribute to the development of AIPC. The ultimate goal of this study is to test if Tocotrienol can be used as adjunctive therapy for inhibiting prostate cancer recurrence after androgen ablation therapy. An orthotopic prostate xenograft model resembling the in vivo progression was developed recently using an androgen dependent prostate cancer cell line (14). We will take advantage of the bioluminescence technique to establish a similar orthotopic prostate xenograft model which can allow us to monitor the growth of the residual tumor and disease progression in living mice. Using this model, we will test if Tocotrienol treatment can reduce or even eliminate the residual tumor after androgen ablation therapy.

List of Research Outputs

Chua C.W., Chiu Y.T., Yuen H.F., Chan K.W., Man K., Wang X., Ling M.T. and Wong Y.C., Suppression of androgen-independent prostate cancer cell aggressiveness by FTY720: validating Runx2 as a potential antimetastatic drug screening platform, Clinical Cancer Research. 2009, 15(13): 4322-4335.

Researcher : Liong EC

List of Research Outputs

Tipoe G.L., Leung T.M., Liong E.C., Lau T.Y.H., Fung M.L. and Nanji A.A., Epigallocatechin-3-gallate (EGCG) reduces liver inflammation, oxidative stress and fibrosis in carbon tetrachloride (CCl₄)-induced liver injury in mice, Toxicology. 2010, 273: 45-52.

Tipoe G.L., Ho M.C.T., Liong E.C., Leung T.M., Lau T.Y.H., Fung M.L. and Nanji A.A., Voluntary oral feeding of rats not requiring a very high fat diet is a clinical relevant model of non-alcoholic fatty liver disease (NAFLD), Histology and Histopathology. 2009, 24(9): 1161-1169.

Researcher : Liu M

List of Research Outputs

Liu M., Wu G. and Yip H.K.F., Expression of TERT and Telomerase aactivity in the rat central nervous system during aging, the University of Hong Kong Li Ka Shing Faculty of Medicine, Research Centre of Heart, Brain, Hormone & Healthy Aging, 5th International Symposium on Healthy Aging. 2010.

Liu M. and Yip H.K.F., The expression of TERT and Id2 in the subventricular zone and neural stem cells in adult mouse, 15th Research Postgraduate Symposium, The University of Hong Kong, Li Ka Shing Faculty of Medicine. 2009.

Researcher : Lo ACY

Project Title:	Oxidative stress and neuronal dysfunction in retinopathy of prematurity
Investigator(s):	Lo ACY, Chung SK, Wong DSH
Department:	Eye Institute
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	05/2009

Abstract:

Retinopathy of prematurity (ROP) is a vasoproliferative retinal disorder that develops in preterm babies, subsequent to them being supported with supplemental oxygen. In ROP, there is initially an increase of retinal blood flow and oxygen delivery. Together with the restricted ability to inactivate reactive oxygen species (ROS), this leads to lipid peroxidation and impairment of ocular circulation, causing vessel constriction, endothelial cell degeneration and finally the typical ROP neo-vascularization. ROP can also result in retinal dysfunction, although the cellular basis for these deficits is unclear. It is generally believed that many illnesses in preterm infants, including ROP, are thought to be related to the action of ROS. Our previous work on retinal ischemia/reperfusion (I/R) showed that retinal neuronal degeneration was associated with increased apoptosis and oxidative stress [1]. In addition, genetic deletion or pharmacological inhibition of aldose reductase (AR), a rate limiting enzyme in the polyol pathway, prevented retinal ganglion cell loss and oxidative stress [1]. More importantly, administration of lutein, an antioxidant, could protect RGC as well as decreased oxidative stress in the injured retina [2], suggesting the importance of oxidative stress in retinal neuronal degeneration. The aim of this proposal is to clarify the role of oxidative stress in the pathogenesis of retinal neuronal injury induced by hyperoxia on a cellular basis and therefore development of ROP in preterm infants using a mouse model of ROP. The potential use of aldose reductase inhibition in preventing oxygen-induced retinopathy will also be explored. Besides neuronal dysfunction, neovascularization is also an important feature in ROP. Retinal neovascularization is thought to occur in response to a hypoxic insult (as a result of VEGF inhibition and reduced vessel growth due to high oxygen), which leads to changes in the existing vasculature and compensatory, albeit pathological, new capillary growth. Therefore, we also aim to determine the extent of neovascularization in our models of ROP upon AR deletion using AR knockout mice [3]. Objectives: 1. To investigate the involvement of oxidative stress in neuronal degeneration after oxygen induced retinopathy 2. To determine the contribution of aldose reductase to neuronal damage in an animal model of retinopathy of prematurity (ROP) Reference 1. Cheung, A.K., et al., Gene deletion and pharmacological inhibition of aldose reductase protect against retinal ischemic injury. Exp Eye Res, 2007. 2. Li, S.Y., et al., Lutein rescued retinal neurons and decreased oxidative stress in a model of acute retinal ischemia/reperfusion. Invest Ophthalmol Vis Sci, 2008. in press. 3. Ho, H.T., et al., Aldose reductase-deficient mice develop nephrogenic diabetes insipidus. Mol Cell Biol, 2000. 20(16): p. 5840-6. 4. Cheung, A.K., et al., Aldose reductase deficiency prevents diabetes-induced blood-retinal barrier breakdown, apoptosis, and glial reactivation in the retina of db/db mice. Diabetes, 2005. 54(11): p. 3119-25.

Project Title:	Neuroscience 2009 Neuroprotective effects of Lycium barbarum polysaccharides on ischemic stroke injury
Investigator(s):	Lo ACY
Department:	Eye Institute
Source(s) of Funding:	URC/CRCG - Conference Grants for Teaching Staff
Start Date:	10/2009
Completion Date:	10/2009

Abstract:

N/A

Project Title:	Oxidative stress, neuronal dysfunction and neovascularization in retinopathy of prematurity
Investigator(s):	Lo ACY, Wong DSH
Department:	Eye Institute
Source(s) of Funding:	Germany/Hong Kong Joint Research Scheme
Start Date:	01/2010

Abstract:

Refer to hard copy

List of Research Outputs

Yeung P.K.K., Lo A.C.Y., Leung J.W.C., Chung S.S.M. and Chung S.K., Targeted overexpression of endothelin-1 in astrocytes leads to more severe cytotoxic brain edema and higher mortality, Journal of Cerebral Blood Flow & Metabolism. 2009, 29: 1891-1902.

Researcher : Lok CKM

List of Research Outputs

Chiu K., Yeung S.C., Ho Y.S., Lok C.K.M., Chan W., So K.F. and Chang R.C.C., IL-10 improves retinal ganglion cell survival in experimental glaucoma model via up-regulation of IGF-1 signaling, Hong Kong Society for Immunology 2010 Annual General Meeting and Scientific Meeting, April 17, 2010.. 2010, 14.

Chiu K., Zhou Y., Yeung S.C., Lok C.K.M., Chan O.O.C., Chang R.C.C., So K.F. and Chiu J., Up-regulation of crystallins is involved in the neuroprotective effect of wolfberry on survival of retinal ganglion cells in rat ocular hypertension model, Journal of Cellular Biochemistry. 2010, 110: 311-320.

Researcher : Lui Kau KWF

List of Research Outputs

Ellis-Behnke R.G., Cheung W.H., Tay D.K.C., Liang Y., Lui Kau K.W.F., Schneider G.E. and So K.F., The control of stem cells in the brain and spinal cord by extracellular nanomatrix system, Society for Neuroscience, Chicago. 2009.

Researcher : Luk SU

List of Research Outputs

Luk S.U., Yap W.N., Chiu Y.T., Lee D.T.W., Ma S.K.Y., Lee K.W., Vasireddy R.S., Wong Y.C., Ching Y.P., Nelson C.O.L.L.E.E.N., Yap Y.L. and Ling M.T., Gamma-tocotrienol as an effective agent in targeting prostate cancer stem cell-like population, International Journal of Cancer. 2010.

Luk S.U., The potential effect of bioactive food supplements in targeting prostate cancer stem cells. 2009, 107 pages.

Researcher : Luk SU

List of Research Outputs

Luk S.U., The potential effect of bioactive food supplements in targeting prostate cancer stem cells. 2009, 107 pages.

Researcher : Mak GWY

List of Research Outputs

Mak G.W.Y., Ng I.O.L. and Ching Y.P., Characterization of CDK5RAP3 in hepatocellular carcinoma, AACR 101st Annual Meeting. 2010.

Mak G.W.Y., Ng I.O.L. and Ching Y.P., Functional characterization of CDK5RAP3 in Human Hepatocellular Carcinoma Cells, 16th Hong Kong International Cancer Congress. 2009.

Researcher : Mak MC

List of Research Outputs

Tong H.Y., Guo J.J., Xu S.X., Mak M.C., Chung S.K., Chung S.S.M., Huang A.L. and Ko B.C.B., Inducible nucleosome depletion at OREBP-binding-sites by hypertonic stress, PLoS ONE. 2009, 4(12): e8435.

Researcher : Man CWY

Project Title:	The polycomb group protein, Bmi-1, induces supernumerary centrosomes and chromosome instability through Id1 in immortalized nasopharyngeal epithelial cells
Investigator(s):	Man CWY, Tsao GSW
Department:	Anatomy
Source(s) of Funding:	Small Project Funding
Start Date:	09/2007

Abstract:

Background: Immortalized nasopharyngeal epithelial cells as study model. Nasopharyngeal carcinoma (NPC) is a common cancer among the local population. EBV is postulated to play an etiological role in the pathogenesis of nasopharyngeal carcinoma (NPC). Immortalized nasopharyngeal epithelial cell lines were used to represent premalignant nasopharyngeal epithelial cell systems which are postulated target cells of EBV transformation. Studies using these models are relevant in understanding the early events involved in the pathogenesis of nasopharyngeal carcinoma. Centrosome-mediated chromosome instability (CIN) facilitates tumorigenesis. Chromosome instability is a common phenotype of solid tumors and CIN may serve as an early driving force to create genetic chaos in premalignant cells. The major mechanism in the induction of CIN involves defects in centrosome duplication (Doxsey et al., 2001; Gollin et al., 2005). Centrosomal aberrations could occur in immortalized cells and pre-malignant lesions (Duensing and Munger, 2002; Pihan et al., 2003); and cells with supernumerary centrosomes could induce multipolar mitoses leading to chromosome mis-segregation and aneuploidy/polyploid; implying that centrosome overduplication may act as an important mediator of CIN during cancer development. However, the molecular mechanisms involved in oncogene driven centrosome-mediated CIN are largely unknown. The polycomb group gene, Bmi-1, a novel gene for NP epithelial cells immortalization. The proto-oncogene, Bmi-1, belongs to the polycomb group complex (Jacobs et al., 1999). Apart from its high expression in stem cells, it is also overexpressed in various human cancers, including nasopharyngeal carcinoma (Kim et al., 2004; Song et al., 2006). The roles of Bmi-1 in inhibition of myc-induced apoptosis through repression of the p16INK4a locus (Itahana et al., 2003), and in telomerase induction (Dimri et al., 2002) have been well-documented. Recent finding suggested that Bmi-1 is a potent gene for immortalization of nasopharyngeal epithelial cells (Song et al., 2006). The EBV encoded LMP1 confers CIN in immortalized NP epithelial cells. Recent study by PI indicated that LMP1 could induce chromosomal instability (CIN) in diploid epithelial cells through inactivation of the tumour suppressor RASSF1A (Man et al., 2007). Our lab has reported a novel function of LMP1 in activation of Id1 which is commonly expressed in cells after escaping cellular senescence (Li et al., 2004). Bmi-1 has been identified as a novel downstream target of LMP1 (Dutton et al., 2007). Id1, the downstream target of LMP1 could induce supernumerary centrosomes. The inhibitor of differentiation, Id1, is a transcription factor which could disturb homeostasis of the centrosome/centriole cycle and could amplify centrosome numbers when cells were overexpressing this oncoprotein (Hasskarl et al., 2004). Id1 also co-localized with centrosomes at both interphase and mitosis (Hasskarl et al., 2004). Hypothesis: Based on the background and the rationale, we hypothesize that Bmi-1 could induce centrosomal instability and chromosome instability in immortalized nasopharyngeal epithelial cells through Id1. Preliminary work done by PI and Co-PI: LMP1's induction of Id1 is mediated through Bmi-1. Both long term and transient expression of LMP1 could upregulate Bmi-1 expression (Figures 1a, 1b) in nasopharyngeal epithelial cells. By using short hairpin RNA targeting Bmi-1 in LMP1 expressing cells, Bmi-1 was shown to be a downstream target of LMP1 mediating Id1 expression in NP models (Figure 1c). In addition, cells transiently expressing Bmi-1 could also induce Id1 in a dose dependent manner (Figures 1d). Establishment of Bmi-1-immortalized nasopharyngeal epithelial cell models. The co-investigator's laboratory has been involved in the establishment of Bmi-1 immortalized nasopharyngeal epithelial cell systems (NP550-Bmi-1 and NP446-Bmi-1) (unpublished data). Bmi-1 could induce centrosome defects in immortalized NP epithelial cells. Our preliminary work showed that Bmi-1 could induce centrosome defects in several Bmi-1 immortalized nasopharyngeal epithelial cells. A nasopharyngeal immortalized cell line stably expressing Bmi-1 (NP550-Bmi-1) (recently established in our laboratory) was examined for centrosomal abnormality using antibody against gamma-tubulin, a major component of the pericentriolar material. Supernumerary centrosomes were observed in the immortalized cells stably expressing Bmi-1 compared to the parental cells before immortalization (Figure 2a). Supernumerary centrosome was not a prominent feature in nasopharyngeal epithelial cells immortalized by telomerase. Nasopharyngeal epithelial cells immortalized by Bmi-1 resulted in a 3.8-fold increase in cells with supernumerary centrosomes. We also detected that the extra centrosomes detected represents duplication of the centrioles. We used another Bmi-1 immortalized cell line which has been reported recently (NPE2-Bmi-1) (Song et al., 2006). Nasopharyngeal epithelial cells were immunofluorescent stained for centrin, an antibody specifically for labeling centrioles. The centrin staining pattern in the parental cell line was normal (Figure 2b). However, quantification of centriole number in the Bmi-1 expressing cells revealed a 4-fold increase in centriole number compared to the centriole number in the parental control. Bmi-1 could induce chromosome instability in immortalized NP epithelial cells. By conventional cytogenetics, we revealed increasing number of triploid and tetraploid populations in Bmi-1 immortalized nasopharyngeal epithelial cell lines (Figure 3). Specific aims: Based on the background, rationale and preliminary data, three specific aims are set for this project: 1. To determine the key signaling events involved in the activation of Bmi-1 by LMP1 and to elucidate the molecular mechanisms involved in Bmi-1's induction of Id1. 2. To examine the effect of Bmi-1 induced Id1 activation on centrosome/centriole homeostasis. 3. To examine Bmi-1's induction of mitotic dysregulation leading to chromosome instability in real time.

List of Research Outputs

Cheung P.P.Y., Deng W., Man C.W.Y., Tse W.W., Srivastava G., Law S.Y.K., Tsao G.S.W. and Cheung A., Genetic alterations in a telomerase-immortalized human esophageal epithelial cell line: Implications for carcinogenesis, Cancer Letters. 2010, 293: 41-51.

Koo C.K., Wong K.L., Man C.W.Y., Tam H.L., Tsao G.S.W., Cheah K.W. and Lam M.H.W., Two-photon plasma membrane imaging in live cells by an amphiphilic, water-soluble cyctometalated platinum (II) complex. , Inorganic Chemistry. ACS publications, 2009, 48(16): 7501-7503.

Law G.L., Wong K.L., Man C.W.Y., Tsao G.S.W. and Wong W.T., A two-photon europium complex as specific endoplasmic reticulum probe., Journal of Biophotonics . 2009, 2(12): 718-724.

Poon C.T., Chan P.S., Man C.W.Y., Jiang F.L., Wong R.N.S., Mak N.K., Kwong D.W.J., Tsao G.S.W. and Wong W.K., An amphiphilic ruthenium (II)-polypyridyl appended porphyrin as potential bifunctional two-photon tumor-imaging and photodynamic therapeutic agent, Journal of Inorganic Biochemistry. 2010, 104: 62-70.

Tsang C.M., Zhang G., Seto E., Takada K., Deng W., Yip Y.L., Man C.W.Y., Hau P.M., Chen H., Cao Y., Lo K.W., Middeldorp J.M., Cheung A. and Tsao G.S.W., Epstein-Barr virus infection in immortalized nasopharyngeal epithelial cells: Regulation of infection and phenotypic characterization. , International Journal of Cancer. 2010, 127: 1570-1583.

Tsang C.M., Zhang G., Seto E., Takada K., Deng W., Yip Y.L., Man C.W.Y., Hau P.M., Cao Y., Lo K.W. and Middeldorp J.M., Epstein-Barr virus infection in immortalized nasopharyngeal epithelial cells: Regulation of infection and phenotypic characterization, Int. J. Cancer. 2010, 127: 1570-83.

Tsao G.S.W., Tsang C.M., Zhang G., Deng W., Hau P.M., Man C.W.Y., Kenzo T., Chen H., Yip Y.L., Lo K.W., Cao Y. and Cheung A., Epstein-Barr virus infection confer stress-resistant property in immortalized nasopharyngeal epithelial cells., Proceedings of American Association of Cancer Research. 2010.

Yip Y.L., Tsang C.M., Jin Y., Deng W., Man C.W.Y., Cheung P.P.Y., Chen H., Cheung A. and Tsao G.S.W., The Epstein-Barr virus-encoded LMP1 extended the life span and immortalized nasopharyngeal epithelial cells., Hong Kong International Cancer Congress . 2009.

Researcher : Mi X

List of Research Outputs

Fu Q., Li X., Yip H.K.F., Shao Z.H., Wu W., Mi X. and So K.F., Combined effect of brain-derived neurotrophic factor and LINGO-1 fusion protein on long-term survival of retinal ganglion cells in chronic glaucoma, Neuroscience Bulletin. 2009, 25(1): 171-172.

Mi X., Chiu K., Van G., Leung J.W.C., Lo A.C.Y., Chung S.K., Chang R.C.C. and So K.F., The effect of lycium barbarum (wolfberry) on the expression of endothelin-1 and its receptors in an ocular hypertension model of glaucoma, 5th International Symposium on Healthy Aging. 2010, Page 55.

Researcher : Niu C

List of Research Outputs

Niu C. and Yip H.K.F., Brain-derived neurotrophic factor (BDNF) regulates telomerase neuroprotective activity through activation of ERK1/2/C-Myc and PI3K/Akt/NFκB pathways in rat spinal cord motor neurons, the University of Hong Kong Li Ka Shing Faculty of Medicine, Research Centre of Heart, Brain, Hormone & Healthy Aging, 5th International Symposium on Healthy Aging. 2010.

Niu C. and Yip H.K.F., Telomerase Expression And Activity Promote Retinal Ganglion Cell Survival After Optic Nerve Injury, US Society of Neuroscience Annual Meeting. 2009.

Niu C., Tsao G.S.W. and Yip H.K.F., The anti-apoptotic role of telomerase in spinal cord motor neurons, 15th Research Postgraduate Symposium, The University of Hong Kong, Li Ka Shing Faculty of Medicine. 2009.

Researcher : O WS

Project Title:	Adrenomedullin in the female reproductive system: gene expression in the ovary and the uterus, possible roles in reproduction and interactions with endothelin-1 and gonadotrophins.
Investigator(s):	O WS, Tang F
Department:	Anatomy
Source(s) of Funding:	General Research Fund (GRF)
Start Date:	09/2007

Abstract:

To study the distribution and the gene expression of adrenomedullin (AM) and its receptor components in the ovary; to study the changes of AM on follicular development and formation of corpora lutea: interaction with gonadotrophins and endothelin (ET); to study the effects of AM on steroidogenesis in follicles and corpora lutea: interaction with gonadotrophins and ET; to study the control of AM in isolated follicles and corpora lutea by gonadotrophins and ET and the control of ET by AM; to study the changes in gene expression of AM and its receptor components in the ovary in early pregnancy and in the uterus during early, mid and late pregnancy, and to relate this to the gene expression of ET and its receptors; to study the functional interaction of AM with ET in the uterus during pregnancy: implantation and placenta development.

Project Title:	The functional significance of a novel uterine growth factor in embryo development
Investigator(s):	O WS, Chow PH
Department:	Anatomy
Source(s) of Funding:	Small Project Funding
Start Date:	11/2008
Completion Date:	08/2010

Abstract:

Objectives: 1. To study the effect of GDF-8 on the development of hamster embryos in culture; 2. To investigate the inner cell mass (ICM) to trophectoderm (TE) ratio change in blastocysts cultured in GDF-8; 3. To study the effect of GDF-8 treatment on the energy metabolism (ATP content, oxygen consumption, lactate generation and mitochondria distribution) in the ICM and TE of blastocysts. Background The TGF-β superfamily encompasses a large number of structurally related molecules; examples of which include TGF- β1-3, growth differentiation factors (GDF), nodal molecules, activins, inhibins and bone morphogenetic proteins (Peng 2003; Jones et al., 2006). In reproduction, these molecules function in regulating immune responses in the uterus, embryogenesis and embryonic implantation (Dimitriadis et al., 2005; Perrier d’Hauterive et al., 2005; Jones et al., 2006). Recently, results from our GRF funded project showed the presence of a novel member of the TGF-β superfamily, GDF-8, in the uterine fluid during the peri-implantation period. Absence of accessory sex gland secretions from the mating studs increases the amount of GDF-8 in the uterine fluid of the female at 72h post coitus. We also found that deletion of paternal accessory sex glands secretion compromised developmental potential of the sired preimplantation embryos because of dysregulation of blastomeric cell cycle regulations p53 and p21 (Wong et al., 2008). We propose to study the function of GDF-8 in the control of blastocyst development, especially on the differentiation of the trophectoderm and the inner cell mass. The establishment of a correct ratio of inner cell mass and trophectoderm in a blastocyst is critical to subsequent normal embryonic development (Thompson et al., 1995; Walker et al., 1996), and the number of ICM cells is strongly related to the capacity of normal development (Lane and Gardner, 1997). The energy metabolism of the two cell lineage in blastocysts will be studied. At the blastocyst stage, most of the glucose uptake will be converted to lactate (Gardner and Leese, 1990. This will reflect the ability of the embryo to produce ATP. The examination of the mitochondria distribution will also reinforce the developmental energy requirement.

Project Title:	42nd Annual Meeting Society for the Study of Reproduction Adrenomedullin and oviduct function in human and rats
Investigator(s):	O WS
Department:	Anatomy
Source(s) of Funding:	URC/CRCG - Conference Grants for Teaching Staff
Start Date:	07/2009
Completion Date:	07/2009

Abstract:

N/A

Project Title:	The role of adrenomedullin in human oviduct
Investigator(s):	O WS, Tang F
Department:	Anatomy
Source(s) of Funding:	Small Project Funding
Start Date:	11/2009

Abstract:

Objectives: 1. To confirm the expression of adrenomedullin (ADM ) in human oviductal tissue; 2. To study the effect of oestradiol and progesterone changes on ADM in human oviductal tissue that simulates the hormonal changes in the menstrual cycle; 3. To study the effect of ADM on ciliary beat frequency in the ciliated epithelium of human oviductal mucosa; 4. To study the sperm-oviduct interaction in regulation of ADM production by oviductal tissue. 5. To study the interaction of ADM and endothelin 1 (EDN) in the control of oviductal contractility. Background Adrenomedullin (ADM) is a peptide hormone belonging to the calcitonin/calcitonin-gene related peptide (CGRP)/amylin family. This family of peptides has the common actions opposite to that of endothelin 1 (EDN), a potent constrictor. Our laboratory has been studying ADM in the male and female reproductive systems. In the male, ADM is produced in the testis, accessory sex glands including the prostate, seminal vesicle and the epididymus (Hwang et al., 2003; Li et al., 2006;Marinoni et al., 2005; Chan et al., 2008 a & b). ADM levels are high in the seminal plasma and it can increase sperm motility (Chiu PCN and Yeung, unpublished data). In the female, the expression of ADM in the endometrium is higher than that in the uterine stroma and myometrium. It has been proposed that ADM may promote endometrial angiogeneisis, regulate uterine contraction and involved in implantation (Laoag-Fernandez et al., 2000, Nikitenko et al., 2000; Di Iorio et al., 1998). ADM acts through its receptor, calcitonin receptor-like receptor (CRLR) whose function is modulated by receptor activity modifying proteins (RAMPs). After coitus, ejaculated spermatozoa are deposited in the vagina and they have to traverse the uterus to reach the oviduct where sperm capacitation, fertilization and early pre-implantation embryonic development occur. These physiological events involve the intimate contact between the gamete and the oviductal epithelium. The oviduct provides the best microenvironment for early embryonic development. It has been shown that the presence of sperm upregulates the expression of oviductal ADM in mice, suggesting a possible physiological role of ADM in this part of the female reproductive tract (Fazeli et al., 2004). Preliminary work in our group has demonstrated the expression of ADM protein and mRNA in rat oviduct by immunohistochemical staining and RT-PCR. ADM and pre-proADM mRNA are lowest at oestrus and CRLR mRNA are low at dioestrus and metoestrus and RAMP2 are higher at proestrus (Li et al., 2008). ADM immunoreactivity has been localized to the ciliated oviductal epithelial cells, especially the cilia on the apical surface. In vitro ADM treatment increases dose-dependently the ciliary beat frequency of oviductal epithelium at different stages of the oestrous cycle. The effect is counteracted on the addition ADM/CGRP receptor antagonist that acts as a competitive antagonist of ADM. Contact co-culture of oviductal tissue with rat sperm significantly increases ADM secretion from the oviductal tissue when compared with oviductal tissue having non-contact co-culture with sperm and with oviductal tissue alone as control. These data is consistent with possible physiological functions of ADM in the oviduct. References 1. Chan YF, OWS, Tang F (2008) Biol Reprod 78:773-9. 2. Chan YF, Tang F, O WS (2008) Biol Reprod 78:780-5. 3. Di Iorio R, Marinoni E, Cosmi EV (1998) Gynecol Endocrinol 12:429-437. 4. Fazeli A, Affara NA, Hubank M, Holt WV (2004) 71:60-65. 5. Hwang ISS, Autleitano DJ, Wong PYD, Leung GPY, Tang F (2003) Biol. Reprod. 68: 2005-2012. 6. Laoag-Fernandez JB, Otani T, maruo T. Endocrinology (2000) 21: 138-147. 7. Li YY, Hwang ISS, OWS, Tang F (2006) Biol Reprod. 75:183-8. 8. Li YY, Li L, Hwang ISS, Tang F, O WS (2008) Biol Reprod 78:200-8. 9. Nikitenko LL, MacKenzi IZ, Rees MC, Bicknell R. (2000) Mol Hum Reprod 6:811-9. 10. Marinoni E, Di Iorio R, Villaccio B, Velluci O, Di Netta T, Sessa M, Letizia C, Cosmi EV (2005) Eur J Obstet Gynecol Reprod Biol 122: 195-8.

List of Research Outputs

Chiu C.N., Liao S., Lam K.W., Tang F., Ho J.C.M., Ho P.C., O W.S., Yao Q.Y. and Yeung W.S.B., Adrenomedullin regulates sperm motility and oviductal ciliary beat via cyclic adenosine 5'-monophosphate/protein kinase A and nitric oxide, Endocrinology. 2010, 151(7): 3336-3347.

Chiu C.N., Lam K.W., Lee C.L., Chung M.K., Huang W., O W.S., Tang F., Ho P.C. and Yeung W.S.B., The role of adrenomedullin in regulating human sperm motility , In: European Society of Human Reproduction and Embryology, 26th Annual Meeting of the European-Society-of-Human-Reproduction-and-Embryology Rome, Italy, Jun 27-30, 2010. ESHRE, P-059.

Li L., Tang F. and O W.S., Adrenomedullin in rat corpus luteum and its role in steroidogenesis during pregnancy, Biology of Reproduction. 2009, 81: 542.

Li L., Hwang I.S.S., Tang F., O W.S. and Li Y.Y., Coexpression of adrenomedullin and its receptors in the reproductive system of the rat: effects on sterold secretion in rat ovary, Yakhteh Medical Journal. 2009, 11(1): 36.

Li R.H.W., Chiu C.N., Cheung M.P.L., Yeung W.S.B. and O W.S., Effect of leptin on motility, capacitation and acrosome reaction of human spermatozoa, International Journal of Andrology. 2009, 32: 687-694.

Li R.H.W., Liao S., Chiu C.N., Tam W.W., Ho J.C.M., Ng E.H.Y., Ho P.C., Yeung W.S.B., Tang F. and O W.S., Expression of adrenomedullin in human oviduct, its regulaton by the hormonal cycle and contact with spermatozoa, and its effect on ciliary beat frequency of the oviductal epithelium, Journal of Clinical Endocrinology and Metabolism. 2010, 95(9): E18-E25.

O W.S., Liao S., Sun J.Z., Ho J.C.M., Chiu C.N., Ng E.H.Y., Yeung W.S.B., Li R.H.W. and Tang F., Adrenomedullin and oviduct function in human and rats, Biology of Reproduction. 2009, 81: 99.

O W.S., Li L., Cheung M.P.L. and Tang F., The role of adrenomedullin in embryo implantation in the rat, The First State Key Laboratory of Reproductive Biology on Frontiers in Perrimplantation Biology. 2010, 60.

Poon H.K., Lee K.H., Wong C.L., O W.S. and Chow P.H., A lack of contact of sperm with accessory sex gland secretions deregulates DNA methylation and imprinted gene expression in rodent embryos, Systems Biology in Reproductive Medicine. 2009, 55: 200-213.

Wong C.L., Wong Y.Y., Ho W.K., Poon H.K., Cheung M.P.L., O W.S. and Chow P.H., Growth-differentiation factor-8 (GDF-8) in the uterus: its identification and functional significance in the golden hamster, Reproductive Biology and Endocrinology. 2009, 7: 134-147.

Zhao W., O W.S., Fung Y.S. and Cheung M.P.L., Analysis of mitochondria by capillary electrophoresis: Cardiolipin levels decrease in response to carbonyl cyanide 4-(trifluoromethoxy) phenylhydrazone, European Journal of Lipid Science and Technology. 2010, 112: 1058-1066.

Researcher : Poon HF

List of Research Outputs

Poon H.F., Xu H. and Ching Y.P., Characterization of the Roles of PAK5 in Neuronal Development , In: Prague, Czech Republic, 34th FEBS Congress: Life's Molecular Interactions. 2009.

Poon H.F., Characterization of the roles of PAK5 in neuronal cell differentiation. 2009, 88 pages.

Researcher : Poon HF

List of Research Outputs

Poon H.F., Xu H. and Ching Y.P., Characterization of the Roles of PAK5 in Neuronal Development , In: Prague, Czech Republic, 34th FEBS Congress: Life's Molecular Interactions. 2009.

Poon H.F., Characterization of the roles of PAK5 in neuronal cell differentiation. 2009, 88 pages.

Researcher : Qiu G

List of Research Outputs

Qiu G., Liu S. and So K.F., Dietary restriction and brain health, Neuroscience Bulletin. 2010, 26(1): 55-65.

Yau S.Y., Lau W.M., Tong J., Wong R., Ching Y.P., Qiu G., Tang S.W., Lee T.M.C. and So K.F., Hippocampal cytogenesis and dendritic plasticity support running-enhanced memory and depression behavior, Proceedings of the International Anatomical Sciences and Cell Biology Conference, May 26-29, 2010. 37.

Yau S.Y., Lau W.M., Tong J., Wong R., Ching Y.P., Qiu G., Tang S.W., Lee T.M.C. and So K.F., Hippocampal cytogenesis and dendritic plasticity support running-enhanced memory and depression behaviour in stressed rat, The 4th Beijing International Forum on Rehabilitation, Oct. 28-30, 2009. 6-7.

Yau S.Y., Lau W.M., Tong J.B., Ching Y.P., Qiu G., Lee T.M.C. and So K.F., Hippocampal neurogenesis and dentritic enrichment are involved in neuroprotective of physical exercise on stress., Neuroscience Bulletin. . 2009, 25 Supp 1: 379-380.

Researcher : Qiu G

List of Research Outputs

Qiu G., Liu S. and So K.F., Dietary restriction and brain health, Neuroscience Bulletin. 2010, 26(1): 55-65.

Yau S.Y., Lau W.M., Tong J., Wong R., Ching Y.P., Qiu G., Tang S.W., Lee T.M.C. and So K.F., Hippocampal cytogenesis and dendritic plasticity support running-enhanced memory and depression behaviour in stressed rat, The 4th Beijing International Forum on Rehabilitation, Oct. 28-30, 2009. 6-7.

Researcher : Schneider GE

List of Research Outputs

Ellis-Behnke R.G., Liang Y., Guo J., Tay D.K.C., Schneider G.E., Teather L.A., Wu W. and So K.F., Forever young: how to control the elongation, differentiation and proliferation of cells using nanotechnology, Cell Transplantation. 2009.

Ellis-Behnke R.G., Cheung W.H., Tay D.K.C., Liang Y., Lui Kau K.W.F., Schneider G.E. and So K.F., The control of stem cells in the brain and spinal cord by extracellular nanomatrix system, Society for Neuroscience, Chicago. 2009.

Researcher : So KF

Project Title:	Nanobiomedical manufacturing: the workforce of tomorrow
Investigator(s):	So KF, Ellis-Behnke RG, Tay DKC, Liang Y
Department:	Anatomy
Source(s) of Funding:	Innovation and Technology Support Programme
Start Date:	09/2006

Abstract:

The goal is to not only understand the variation in the manufacturing process, but to understand how to remove that variation. At the same time the process needs to be optimized for cost, purity and the quantities that will be needed for use in humans.

Project Title:	Molecular mechanism of survival of melanopsin-expressing retinal ganglion cells after glaucoma or optic nerve injury
Investigator(s):	So KF
Department:	Anatomy
Source(s) of Funding:	Small Project Funding
Start Date:	10/2007
Completion Date:	09/2009

Abstract:

Our group has previously identified a subtype of retinal ganglion cells (RGCs) that expresses melanopsin, survived relatively longer in the ocular hypertension (OH) model, whereas a significant number of superior colliculus-projecting RGCs (scRGCs) died in the process. In a more severe and acute type of injury, such as optic nerve transection (ONT), that leads to a dramatic loss of RGCs, approximately half of the cells die within a week and more than 90% of cells are lost two weeks post-operation. The differential cell death in these models suggests that a population of neurons are more resistant to injury. Elucidating the survival pathways can provide insights for neuroprotective strategies. Melanopsin is a novel photopigment that exclusively expressed in a small population of RGCs. This group of neurons is found to be intrinsically photosensitive and contributed to non-visual photoperception, including photoentrainment, as they project their axons to the retinohypothalamic tract and suprachiasmatic nucleus (SCN). The distinct pathway allows these melanopsin-expressing RGCs (mRGCs) response to light independent of the input from classical photoreceptors, rods and cones. Recently, mRGCs are shown to be less susceptible to death after complete optic nerve transaction (ONT) in mice and induction of ocular hypertension (OH) in rats. The resistance to injury may be probably due to the extensively branched dendrites and the unique intrinsic properties of melanopsin. By far, there is no definitive answer except postulations. In the present proposal, we plan to study the factors that contribute to the injury-resistant property of melanopsin-expressing retinal ganglion cells (mRGCs). Since phosphatidylinositol- 3 kinase (PI3K)/Akt signaling pathway is one of the well known pathways for neuronal cell survival, we will then investigate the survival of mRGCs by applying the PI3K/Akt specific inhibitors after injury. Other survival signaling pathways will also be investigated when needed.

Project Title:	Investigate retinal neuromechanisms of seasonal affective disorder
Investigator(s):	So KF, Yang J, Xiao CX, Nan Y
Department:	Anatomy
Source(s) of Funding:	NSFC/RGC Joint Research Scheme
Start Date:	01/2009
Completion Date:	12/2010

Abstract:

To investigate the neuromechanisms of seasonal affective disorders (SAD) from the aspects of neurotransmitter - dopamine and the retinal ganglion cells (RGCs) that modulate the circadian rhythms. (1) investigating the correlation between depression-like behaviors in SAD animal models (sand rats) and intraocular administration of dopamine agonist/antagonist; (2) Studying physiological properties of RGCs (Specifically ipRGCs and cSCN-RGCs) in dopamine agonist/antagonist treated animals (including normal and SAD animals) with emphasis on general receptive field properties, luminance sensitivity, temporal and spatial sensitivity, signal to noise ratio, and effects of pharmacological agents on these RGCs. Correlate visual response properties of RGCs with SAD-related neurotransmitter (Specifically dopamine) administration.

Project Title:	Steroid therapy: effect of corticosteroid and antidepressant on sexual behavior
Investigator(s):	So KF
Department:	Anatomy
Source(s) of Funding:	Small Project Funding
Start Date:	01/2009

Abstract:

Major depressive disorder is usually associated with sexual dysfunction [1]. According to a study conducted by Mathew and Weinman [2], the sexual dysfunction of males with depression could be presented as decreased libido, erectile dysfunction or delayed ejaculation. The prevalence rate among the patient population is several times higher than the general population. Until now, the causal relationship between depression and sexual dysfunction is not clear [3], but relieve of sign and symptoms of depression may help to alleviate the associated sexual dysfunction. Major depression is usually associated with elevated corticosteroid level (hypercortisolemia) [4]. Since stress is involved in the etiology of depressive disorder [5], it is suggested that de-regulation of corticosteroid system(Hypothalamic-pituitary-adrenal gland axis), which is responsible for maintaining homeostasis when confronting stress, may be the cause of stress-induced disorders, including depression. Stress, either environmental or physical, is a cause of sexual behavior inhibition [6]. It was reported that social stress decreases sexual behavior of subordinate animals and these animals showed higher plasma corticosterone level [7]. Direct administration of corticosterone causes inhibition of male sexual behavior. [8]. The inhibition may be due to activation of serotonin receptor subtype 2A (5-HT2A), which is activated by corticosterone [8]. When 5-HT2A specific agonist DOI was injected to male rats, sexual arousal and behavior, including number of ejaculation and intromission, were suppressed [8, 9]. Collectively, these evidences suggest that stress and stress-related disorder inhibit male sexual behavior, which is mediated by corticosteroid. Selective serotonin reuptake inhibitors (SSRIs) are commonly prescribed for treatment of major depressive disorder [10]. SSRIs prevent reuptake of serotonin into presynaptic compartment and increase serotonin concentration at the synaptic cleft, which in turns affect mood, aggression, and sexual behaviour. Currently there are over 14 subtypes of serotonin receptors which are responsible for different physiological functions [11]. 5-HT1A was shown to accelerate ejaculation upon activation while 5-HT1B and 5-HT2C activation inhibit ejaculation [10, 12]. The interaction between SSRI, corticosterone and different serotonin receptors may cause sexual dysfunction commonly seen in depression patients. Increasing evidence supports the notion that main olfactory system plays a critical role in rodent copulatory behavior [13]. It is possible that corticosterone and paroxetine affect copulation through the olfactory system. Our previous study demonstrated that corticosterone suppresses neurogenesis (new neuron production) in hippocampus and subventricualr zone (SVZ) while paroxetine (one form of SSRI) could counteract the effect [14].The altered hippocampal neurogenesis could be the underlying reason of decremented memory found in depressive patients. To find out how do corticosterone and paroxetine affect sexual behavior, several interrelated components of the olfactory system could be studied. They are: 1. Subventricular zone; 2. Olfactory epithelium and 3. Brain regions involved in sexual activity: medial amyedala (AM), bed nucleus of stria terminalis (BNST) and medial preoptic areas (MPOA). Since olfactory epithelium is another area with continuous adult neurogenesis, it is possible that the effect of corticosteroid and paroxetine exert similar effect on this region. A study has proven that high dose of glucocorticoid reduces olfactory epithelium cell proliferation [15]. So this study will test whether paroxetine could reverse the effect of corticosterone on olfactory epithelium neurogenesis. As stated above, the precise nature and mechanism of sexual dysfunction in depression patients or stressed individuals have not been fully appreciated. Additionally, it is unclear whether there is interaction between depression state and SSRIs on sexual behavior. To address this issue, an animal paradigm is utilized. Sprague-Dawley rats are divided into four groups: 1. Corticosterone treatment group; 2. SSRI (paroxetine) treatment group; 3. Co-treatment (both corticosterone and SSRI) group and 4. control group. Subchronic corticosterone treatment is used to induce inhibited male sexual behavior, and paroxetine was administered to test whether the sexual performance will be improved with antidepressant treatment. It is expected that the addition of paroxetine may reverse the inhibited sexual behavior due to corticosterone treatment, and this is caused by affecting neurogenesis in the olfactory system and in turn the neuronal signal transduction in various relayed nuclei of the olfactory system in the CNS. Thus we will also investigate neurogenesis and molecular mechanism in these parts of CNS. by the neurogenesis. 4. To study the molecular mechanisms involved in neurogenesis. These findings could significantly alter treatment regime of patients under steroid treatment.

Project Title:	RAGE (receptor for advanced glycation end products), Abeta (beta-amyloid peptide) and ET-1 (endothelin-1) probing their effects in glaucoma with transgenic mice over-expressing ET-1 in endothelial or glial cells
Investigator(s):	So KF, Chung SK, Lo ACY
Department:	Anatomy
Source(s) of Funding:	General Research Fund (GRF)
Start Date:	01/2009

Abstract:

(1) To determine the heterogeneous expression of RAGE, Abeta and ET-1 in various retinal cell types after chronic ocular hypertension in rat; (2) To assess if there is any species difference in the expression of RAGE, Abeta and ET-1 after induction of ocular hypertension by comparing the expression in rat and mouse retinal tissues; (3) To compare the differential effects of vascular and glial ET-1 on retinal morphological changes and functional deficits using TET-1 and GET-1 transgenic mice without/with the induction of ocular hypertension; ( 4) To understand the pathway of neuroprotection mediated by pharmacological inhibition of ET-1 in glaucomatous damage; (5) To investigate the expression of proinflammatory cytokines and its involvement in RGC death in experimental glaucoma.

Project Title:	Neuroprotective effect of physical exercise on stressed animal model
Investigator(s):	So KF
Department:	Anatomy
Source(s) of Funding:	Small Project Funding
Start Date:	01/2010

Abstract:

The hippocampus, a brain structure essential for learning and memory, is showed to continuously generate new neurons throughout life. Recently, the neuropathological changes of hippocampus caused by glucocorticoid are believed to be involved in depressive disorders and cognitive impairments. In contrast, physical exercise is known to protect against the harmful consequences of stress. However, the neurological basis of beneficial effect of exercise is still unclear. We will perform our experiments based on the following aims: 1) To develop and verify an animal model with a graded stress level with corticosteroid injection; 2) To investigate the effect of different dosages of corticosterone on hippocampal neurogenesis, dendritic plasticity and spatial memory 3) To examine the counteracting effect of voluntary exercise on these three aspects; 3) To confirm the role of neurogenesis and dendritic plasticity in neuroprotective effect of exercise with diminished hippocampal cell proliferation using antimitotic drug, Cytosine-b-D-arabinofuranoside infusion; 4) To study the molecular mechanism involved in the hippocampal neurogenesis

Project Title:	Role of JNK3/APP signaling pathway in modulating the apoptosis of optic axotomized retinal ganglion cells
Investigator(s):	So KF
Department:	Anatomy
Source(s) of Funding:	General Research Fund (GRF)
Start Date:	01/2010

Abstract:

1) Whether are APP expression and phosphorylation upregulated in the RGCs by optic nerve axotomy? 2) What is the role of APP in the RGCs survival and apoptosis induced by optic nerve axotomy? 3) What is the role of JNKs in the RGCs survival and apoptosis induced by optic nerve axotomy? ; 4) IV. What is the role of JNKs in regulating the expressions of Pho-JNK, APP and Pho-APP in the RGCs after optic nerve axotomy? 5) Whether does JNK3 modulate the RGC survival and apoptosis in a c-Jun dependent manner? 6) Which molecules related to neuronal cell death are modulated by both JNK3 and APP? 7) Does AICD act as a downstream transcriptional factor of JNK3 in modulating the expression of Noxa, Cytochrome-C and APP?

Project Title:	17th Annual Conference of the American Society for Neural Therapy & Repair Possible involvement of neurogenesis in male rat mating behavior
Investigator(s):	So KF
Department:	Anatomy
Source(s) of Funding:	URC/CRCG - Conference Grants for Teaching Staff
Start Date:	04/2010
Completion Date:	05/2010

Abstract:

N/A

List of Research Outputs

Cai J., Li W., Su H., Qin D., Yang J., Zhu F., Xu J., He W., Guo X., Labuda K., Peterbauer A., Wolbank S., Zhong M., Li Z., Wu W., So K.F., Redl H., Zeng L., Esteban M.A. and Pei D., Generation of human induced pluripotent stem cells from umbilical cord matrix and amniotic membrane mesenchymal cells, The Journal of Biological Chemistry. 2010, 285(15): 11227-11234.

Chang R.C.C., Ho Y.S., Yu M.S. and So K.F., Medicinal and nutraceutical uses of wolfberry in preventing neurodegeneration of Alzheimer's disease, In: Charles Ramassamy and Stéphane Bastianetto, Recent Advances on Nutrition and the Prevention of Alzheimer's Disease, 2010. Kerala, India, Transworld Research Network, 2010, 169-185.

Chang R.C.C., Chiu K., Ho Y.S. and So K.F., Modulation of neuroimmune responses on glia in the central nervous system: implicaion in therapeutic intervention against neuroinflammation, Cellular and Molecular Immunology. 2009, 6(5): 317-326.

Cheung Y.T., Zhang Q., Hung H.L., Lai S.W., Yu M.S., So K.F. and Chang R.C.C., Investigating the temporal transition of autophagy and apoptosis in neurons stressed by low molecular weight beta-amyloid peptide toxicity, 11th International Geneva/Springfield Symposium on Advances in Alzheimer Therapy, March 24-27, 2010 Geneva. 2010, 42.

Chiu K., Yeung S.C., Ho Y.S., Lok C.K.M., Chan W., So K.F. and Chang R.C.C., IL-10 improves retinal ganglion cell survival in experimental glaucoma model via up-regulation of IGF-1 signaling, Hong Kong Society for Immunology 2010 Annual General Meeting and Scientific Meeting, April 17, 2010.. 2010, 14.

Chiu K., Yeung S.C., So K.F. and Chang R.C.C., Modulation of morphological changes of microglia and neuroprotection by monocyte chemoattractant protein-1 in experimental glaucoma, Cellular and Molecular Immunology. 2010, 7: 61-68.

Chiu K., Zhou Y., Yeung S.C., Lok C.K.M., Chan O.O.C., Chang R.C.C., So K.F. and Chiu J., Up-regulation of crystallins is involved in the neuroprotective effect of wolfberry on survival of retinal ganglion cells in rat ocular hypertension model, Journal of Cellular Biochemistry. 2010, 110: 311-320.

Ellis-Behnke R.G., Liang Y., Guo J., Tay D.K.C., Schneider G.E., Teather L.A., Wu W. and So K.F., Forever young: how to control the elongation, differentiation and proliferation of cells using nanotechnology, Cell Transplantation. 2009.

Ellis-Behnke R.G., Liang Y., Cheung W.H., So K.F., Wu W. and Tay D.K.C., Redefining tissue engineering for nanomedicine: Visualizing the progress of regenerating axons in the mammalian visual system after complete transection and treatment with self-assembling nanomaterial, 6th Annual World Congress for Brain Mapping and Image Guided Therapy, Harvard Medical School, Boston MA. 2009.

Ellis-Behnke R.G., Cheung W.H., Tay D.K.C., Liang Y., Lui Kau K.W.F., Schneider G.E. and So K.F., The control of stem cells in the brain and spinal cord by extracellular nanomatrix system, Society for Neuroscience, Chicago. 2009.

Ellis-Behnke R.G., Liang Y., Cheung S.W.H., So K.F. and Tay D.K.C., Using a self-assembling nanopeptide to achieve ocular hemostasis without causing clotting or secondary inflammation, ARVO 2010. Program No. 427, Poster No. D1131.

Fu Q., Li X., Yip H.K.F., Shao Z.H., Wu W., Mi X. and So K.F., Combined effect of brain-derived neurotrophic factor and LINGO-1 fusion protein on long-term survival of retinal ganglion cells in chronic glaucoma, Neuroscience Bulletin. 2009, 25(1): 171-172.

Ho Y.S., So K.F. and Chang R.C.C., Anti-aging herbal medicine - How and why can they be used in aging-associated neurodegenerative disease?, Ageing Research Reviews. 2010, 9: 354-362.

Ho Y.S., Yu M.S., Yang X., So K.F., Yuen W.H. and Chang R.C.C., Neuroprotective effects of polysaccharides from wolfberry, the fruits of Lycium barbarum. against homocysteine-induced toxicity in rat cortical neurons, Journal of Alzheimer's Disease. 2010, 19: 813-827.

Ho Y.S., Yang X., Yu M.S., So K.F. and Chang R.C.C., Polysaccharides from Wolfberry (Lycium barbarum) antagonize homocysteine-induced neurotoxicity in cultured cortical neurons, Society for Neuroscience 2009. Program No. 626.3: Poster No. H16.

Ho Y.S., Yu M.S., Yik S.Y., So K.F., Yuen W.H. and Chang R.C.C., Polysaccharides from wolfberry antagonizes glutamate excitotoxicity in rat cortical neurons, Cellular and Molecular Neurobiology. 2009, 29: 1233-1244.

Ho Y.S., Yang X., Wang J., So K.F. and Chang R.C.C., The relationship between ER stress and TAU phosphorylation - Do they affect each other?, 5th International Symposium on Healthy Aging,. 2010, Page 63.

Ho Y.S., So K.F. and Chang R.C.C., Wolfberry (Lycium Barbarum) protects primary corticol neurons against Alzheimer's disease-related pathological damages, Collegium Internationale Neuro-Psychopharmacologicum (CINP) 2010 World Congress. 2010, P-08.

Hong S.J., Chiu K., Ho Y.S., He Y., Che C.T., So K.F., Lin Z.X. and Chang R.C.C., Significance of chrysin from a cognitive-enhanching chinese herb Alphinae oxyphyllae as a source of potential neuroprotective agent, 5th International Symposium on Healthy Aging. 2010, Page 54.

Lau W.M., Yau S.Y., Lee T.M.C., Ching Y.P., Tang S.W. and So K.F., Corticosterone suppresses dendritic maturation of immature neurons in hippocampus, which is counteracted by antidepressant treatment, Neuroscience Bulletin. 2009, 25(1): 450.

Lau W.M., Yau S.Y., Lee C.D., Chang R.C.C. and So K.F., Effect of Lycium Barbarum (Wolfberry) polysaccharide on sexual behavior of male rats, Collegium Internationale Neuro-Psychopharmacologicum (CINP) 2010 World Congress. 2010, P-02.

Lau W.M., Yau S.Y., Lee T.M.C., Ching Y.P., Tang S.W. and So K.F., Effect of corticosterone and paroxetine on masculline mating behavior: Possible involvement of neurogenesis, Pan Pacific Symposium on Stem Cells Research, April 16-19, 2010, Taiwan. 2010, 77.

Lau W.M., Yau S.Y., Lee C.D., Chang R.C.C. and So K.F., Lycium barbarum (wolfberry) polysaccharide facilitates ejaculatory behaviour in male rats. , Annual Meeting of the Australian Neuroscience Society. 2010.

Lau W.M., Yau S.Y., Lee T.M.C., Ching Y.P., Tang S.W. and So K.F., Possible involvement of neurogenesis in male rat mating behavior, Cell Transplantation. 2010, 19(3): 347.

Li S.Y., Yeung C.M., Yu W.Y., Chang R.C.C., So K.F., Wong D.S.H. and Lo A.C.Y., Beneficial effects of lycium barbarum polysaccharides on neurons and blood-retinal barrier in retinal ischemia/reperfusion injury, 5th International Symposium on Healthy Aging. 2010, Page 59.

Li S.Y., Yeung C.M., Chang R.C.C., So K.F., Wong D.S.H. and Lo A.C.Y., Lycium Barbarum Polysaccharides Protects Retina From Ischemia/reperfusion Injury, ARVO 2010 Annual Meeting. 2010.

Li S.Y., Yeung C.M., Yu W.Y., Chang R.C.C., So K.F., Wong D.S.H. and Lo A.C.Y., Protection Of Retinal Neurons By Administration Of Lycium Barbarum (wolfberry) In A Murine Model Of Acute Ischemia/reperfusion Injury, Joint Annual Scientific Meeting of the Hong Kong Society of Neurosciences and the Biophysical Society of Hong Kong. 2010.

Lo A.C.Y., Yeung C.M., Li S.Y., Chang R.C.C., So K.F. and Wong D.S.H., Neuroprotective effects of Lycium barbarum polysaccharides on ischemic stroke injury, Society for Neuroscience 2009. Program No. 150.13: Poster No. K2.

Mi X., Chiu K., Van G., Leung J.W.C., Lo A.C.Y., Chung S.K., Chang R.C.C. and So K.F., The effect of lycium barbarum (wolfberry) on the expression of endothelin-1 and its receptors in an ocular hypertension model of glaucoma, 5th International Symposium on Healthy Aging. 2010, Page 55.

Nan Y., Xiao C., Chen B., Ellis-Behnke R.G., So K.F. and Pu M., Visual response properties of Y cells in the detached feline retina, Investigative Ophthalmology & Visual Science. 2010, 51(2): 1208-1215.

Qiu G., Liu S. and So K.F., Dietary restriction and brain health, Neuroscience Bulletin. 2010, 26(1): 55-65.

So K.F. and Chang R.C.C., Molecular mechanism of neuroprotection in glaucoma using gouqizi (wolfberry), 首都医科大学眼科学院２００９年学朮年会. 2009, 10.

So K.F. and Chang R.C.C., Molecular mechanism of neuroprotection in glaucoma using gouqizi (wolfberry), Hong Kong Journal of Ophthalmology. 2009, 13(1): 8.

So K.F. and Chang R.C.C., Molecular mechanism of neuroprotection in neurodegenerative diseases using gouqizi (wolfberry), 7th AMN Congress and 16th Annual Scientific Meeting of HKNS, Nov. 12-14, 2009 Hong Kong. 2009, 67.

So K.F., Liang Y., Tay D.K.C. and Ellis-Behnke R.G., Nanomedicine for CNS regeneration and instant hemostasis, WACBE World Congress on Bioengineering 2009, July 26-26, 2009, Hong Kong. 2009, 4.

So K.F., Neuro-regeneration research in spinal cord injury, Advances in Physiotherapy Annual Conference, November 14-15, 2009. 17.

So K.F., 納米物料：治療腦損傷新希望, In: L. K. Lam et. al, 育醫造才：探索醫學世界 (Explore the World of Medicine). Hong Kong, The University of Hong Kong Li Ka Shing Faculty of Medicine, 2010, 70-72.

Wang H., Lau W.M., Yau S.Y., Li S.Y., Leung N.E.L.S.O.N., Wang N.I.N.G.L.I., Tang S.W., Lee T.M.C. and So K.F., The roles of paroxetine and corticosterone on adult mammalian retinal ciliary body cell proliferation, The Chinese Medical Journal. 2010, 123: 1305-1310.

Wang H., Lau W.M., Yau S.Y., Li S.Y., Leung N., Wang N.L., Tang S.W., Lee T.M.C. and So K.F., Roles of paroxetine and corticosterone on adult mammalian ciliary body cell proliferation, Chinese Medical Journal. 2010, 123: 1305-1310.

Yang D., Yeung C.M., Li S.Y., Chang R.C.C., So K.F., Wong D.S.H. and Lo A.C.Y., Lycium Barbarum Polysaccharides Protects Brain From Ischemia/reperfusion Injury, Joint Annual Scientific Meeting of the Hong Kong Society of Neurosciences and the Biophysical Society of Hong Kong. 2010.

Yau S.Y., Lau W.M., Tong J., Ching Y.P., Lee T.M.C. and So K.F., Hippocampal cell proliferation and dendritic enrichment is essential for beneficial effects of exercise on stressed animal model, Hellenic Society for Neuroscience, 23rd Annual Meeting, September 13-14, 2009, Greece.. 2009, 78-79.

Yau S.Y., Lau W.M., Tong J., Wong R., Ching Y.P., Qiu G., Tang S.W., Lee T.M.C. and So K.F., Hippocampal cytogenesis and dendritic plasticity support running-enhanced memory and depression behavior, Proceedings of the International Anatomical Sciences and Cell Biology Conference, May 26-29, 2010. 37.

Yau S.Y., Lau W.M., Tong J., Wong R., Ching Y.P., Qiu G., Tang S.W., Lee T.M.C. and So K.F., Hippocampal cytogenesis and dendritic plasticity support running-enhanced memory and depression behaviour in stressed rat, The 4th Beijing International Forum on Rehabilitation, Oct. 28-30, 2009. 6-7.

Yau S.Y., Lau W.M., Tong J.B., Ching Y.P., Qiu G., Lee T.M.C. and So K.F., Hippocampal neurogenesis and dentritic enrichment are involved in neuroprotective of physical exercise on stress., Neuroscience Bulletin. . 2009, 25 Supp 1: 379-380.

Young W. and So K.F., Current status of spinal cord injury research, 7th AMN Congress and 16th Annual Scientific Meeting of HKNS, Nov. 12-14, 2009, Hong Kong. 2009, 82.

Yuan Q., Hu B., Wu Y., Chu T.H., Su H., Zhang W., So K.F., Lin Z. and Wu W., Induction of c-Jun phosphorylation in spinal motoneurons in neonatal and adult rats following axonal injury, Brain Research. 2010, 1320: 7-15.

Yuan T., Liang Y., Tay D.K.C., So K.F. and Ellis-Behnke R.G., Olfactory tract transection enhances adult neurogenesis in piriform cortex, 22nd Biennial Meeting of the International Society of Neurochemistry, Busan Korea. 2009.

Zhang E., Yau S.Y., Lau W.M., So K.F. and Chang R.C.C., Anti-depressive effects of Lycium Barbarum in a rat depression model, Collegium Internationale Neuro-Psychopharmacologicum (CINP) 2010 World Congress. 2010, P-09.

Zhang E., Chang R.C.C. and So K.F., Elucidating beneficial effects of Wolfberry (Lycium barbarum) in experimental depression, Society for Neuroscience 2009. Program No. 549.13: Poster No. X7.

武 ......, 游思.維. and So K.F., 視神经的損傷与修复, In: 童經、魏世輝、游思維, 視路疾病基礎与臨床進展, 人民衛生出版社, 2010, 第二十章 263-269.

Researcher : Su H

Project Title:	Survival, axonal extension and target innervation of murine iPS-induced motoneurons after transplantation into avulsion-injured spinal cords with ventral root reimplantation
Investigator(s):	Su H, Wu W
Department:	Anatomy
Source(s) of Funding:	Small Project Funding
Start Date:	12/2009

Abstract:

A major breakthrough in stem cell biology has been recently reported that fetal and adult somatic cells can be successfully reprogrammed to the pluripotent state using transfection of four pluripotent genes (OCT4, SOX2, Klf, cMYC) (induced pluripotent stem cells, iPSCs) (Takahashi and Yamanaka, 2006; Takahashi et al., 2007). The method is striking in that it can convert somatic cells directly into pluripotent cells, in a manner that is totally independent of the availability of embryonic cells. These cells are considered to be an ideal cell source for transplantation therapy since they are autologous and easily obtainable. An important issue of somatic reprogramming is to generate relevant cell types to enable the repair of tissue damage. A recent study has reported that iPS cells can be efficiently differentiated into neural precursor cells in vitro and transplantation of iPS into the adult brain induces differentiation of dopamine neurons and improves behavior in a rat model of Parkinson’s disease (Werning et al., 2008). A more recent study further demonstrates that human iPS can be induced into motoneuron precursors and electrically active mature motoneurons in vitro, providing a valuable platform of future studies of human motoneuron disease (Karumbayaram et al., 2009). This interesting study leads to an important question: whether these iPS-induced motoneurons can survive, extend axons and innervate targets after transplantation into specific CNS regions of mammals with motoneuron degeneration. Brachial plexus injury often involves root avulsion and is a devastating injury that results in massive motoneuron death and paralysis of the corresponding muscle groups. During the last decade we have focused on using various pharmaceutical factors and surgical intervention to rescue injured motoneurons from degeneration and functional recovery (Wu, 1996; Chai et al., 2000; Gu et al., 2004; Gu et al., 2005). However, the functional outcome and long-term motoneuron survival after root avulsion are still limited despite various above-mentioned approaches were used. Recently cell replacement strategies have been applied to treat neurological disorders with motoneuron degeneration. We isolated neural progenitor cells (NPCs) from fetal spinal cords (Su et al., 2007) and transplanted them into the rat ventral horn immediately or at 6 weeks after root avulsion (Su et al., 2009a; Su et al., 2009b). Unfortunately both acute and chronicle transplantation fail to induce transplanted NPCs in the spinal ventral horn to generate motoneurons (Su et al., 2009a; Su et al., 2009b). The adult spinal cord lacks inductive signals or contains inhibitory factors that make it an unfavorable environment for the differentiation of grafted NPCs (Cao et al., 2001; Park et al., 2002). Using other cell sources or pharmacological inductions may be necessary for successful transplantation therapy in treatment with neurological disorders characterized by motoneuron loss. Therefore, it is of great interest to investigate whether motoneuron precursors induced by iPS in vitro can survive, integrate and extend axons into targets after transplantation into the avulsed ventral horn with root implantation. Results of the present study will surely provide evidence on the therapeutic potentials of iPS in treating neurological disorders with motoneuron degeneration. References Cao, Q.L., Zhang, Y.P., Howard, R.M., Walters, W.M., Tsoulfas, P., Whittemore, S.R., 2001. Pluripotent stem cells engrafted into the normal or lesioned adult rat spinal cord are restricted to a glial lineage. Exp. Neurol. 167, 48–51. Chai,H., Wu, W., So, K.F., Yip, H., 2000. Survival and regeneration of motoneurons in adult rats by re-implantation of ventral root following spinal root avulsion. NeuroReport 11, 1249-1252. Gu, H.Y., Chai, H., Zhang, J.Y., Yao , Z.B., Zhou, L.H., Wong, W.M., Bruce, I., Wu, W., 2004. Survival, regeneration and functional recovery of motoneurons in adult rats by reimplantation of ventral root following spinal root avulsion. Eur. J. Neurosci. 19, 2123-2131. Gu, H.Y., Chai, H., Zhang, J.Y., Yao, Z.B., Zhou, L.H., Wong, W.M., Bruce, I.C., Wu, W.T., 2005. Survival, regeneration and functional recovery of motoneurons after delayed reimplantation of avulsed spinal root in adult rat. Exp. Neurol. 192, 89-99. Karumbayaram S, Novitch BG, Patterson M, Umbach JA, Richter L, Lindgren A, Conway AE, Clark AT, Goldman SA, Plath K, Wiedau-Pazos M, Kornblum HI, Lowry WE. 2009. Directed differentiation of human-induced pluripotent stem cells generates active motor neurons. Stem Cells 27, 806-11. Park, K.I., Ourednik, J., Ourednik, V., Taylor, R.M., Aboody, K.S., Auguste, K.I., Lachyankar, M.B., Redmond, D.E., Snyder, E.Y., 2002. Global gene and cell replacement strategies via stem cells. Gene Ther. 9, 613-624. Su, H., Chu, T., Wu, W., 2007. Lithium enhances proliferation and neuronal differentiation of neural progenitor cells in vitro and after transplantation into the adult rat spinal cord. Exp. Neurol. 206, 296-307. Su, H., Zhang, W., Guo, J., Guo, A., Yuan, Q., Wu, W., 2009a. Neural progenitor cells enhance the survival and axonal regeneration of injured motoneurons after transplantation into the avulsed ventral horn of adult rats. J. Neurotrauma 26, 67-80. Su, H., Zhang, W., Guo, J., Guo, A., Yuan, Q., Wu, W., 2009b. Lithium enhances the neuronal differentiation of neural progenitor cells in vitro and after transplantation into the avulsed ventral horn of adult rats through the secretion of brain-derived neurotrophic factor. J. Neurochem. 108, 1385-1398. Takahashi K, Yamanaka S, 2006. Induction of pluripotent stem cells from mouse embryonic and adult fibroblast cultures by defined factors. Cell 126, 663-676. Takahashi K, Okita K, Nakagawa M, Yamanaka S, 2007. Induction of pluripotent stem cells from fibroblast cultures. Nat Protoc. 2, 3081-3089. Wernig M, Zhao JP, Pruszak J, Hedlund E, Fu D, Soldner F, Broccoli V, Constantine-Paton M, Isacson O, Jaenisch R. 2008. Neurons derived from reprogrammed fibroblasts functionally integrate into the fetal brain and improve symptoms of rats with Parkinson's disease. Proc Natl Acad Sci U S A 15, 5856-61. Wu, W., 1996. Potential roles of gene expression change in adult rat spinal motoneurons following axonal injury: a comparison among c-jun, off-affinity nerve growth factor receptor (LNGFR), and nitric oxide synthase (NOS). Exp. Neurol. 141, 190-200.

List of Research Outputs

Cai J., Li W., Su H., Qin D., Yang J., Zhu F., Xu J., He W., Guo X., Labuda K., Peterbauer A., Wolbank S., Zhong M., Li Z., Wu W., So K.F., Redl H., Zeng L., Esteban M.A. and Pei D., Generation of human induced pluripotent stem cells from umbilical cord matrix and amniotic membrane mesenchymal cells, The Journal of Biological Chemistry. 2010, 285(15): 11227-11234.

Yuan Q., Hu B., Wu Y., Chu T.H., Su H., Zhang W., So K.F., Lin Z. and Wu W., Induction of c-Jun phosphorylation in spinal motoneurons in neonatal and adult rats following axonal injury, Brain Research. 2010, 1320: 7-15.

Researcher : Sy SMH

List of Research Outputs

Huen M.S.Y., Sy S.M.H. and Chen J., BRCA1 and its toolbox for the maintenance of genome integrity, NATURE REVIEWS MOLECULAR CELL BIOLOGY . 2010, 11(2): 138-48.

Huen M.S.Y., Huang J., Leung J.W.C., Sy S.M.H., Leung K.M., Ching Y.P., Tsao G.S.W. and Chen J., Regulation of Chromatin Architecture by the PWWP Domain-Containing DNA Damage-Responsive Factor EXPAND1/MUM1, MOLECULAR CELL. 2010, 37(6): 854-864.

Researcher : Tang SW

List of Research Outputs

Lau W.M., Yau S.Y., Lee T.M.C., Ching Y.P., Tang S.W. and So K.F., Corticosterone suppresses dendritic maturation of immature neurons in hippocampus, which is counteracted by antidepressant treatment, Neuroscience Bulletin. 2009, 25(1): 450.

Lau W.M., Yau S.Y., Lee T.M.C., Ching Y.P., Tang S.W. and So K.F., Effect of corticosterone and paroxetine on masculline mating behavior: Possible involvement of neurogenesis, Pan Pacific Symposium on Stem Cells Research, April 16-19, 2010, Taiwan. 2010, 77.

Lau W.M., Yau S.Y., Lee T.M.C., Ching Y.P., Tang S.W. and So K.F., Possible involvement of neurogenesis in male rat mating behavior, Cell Transplantation. 2010, 19(3): 347.

Wang H., Lau W.M., Yau S.Y., Li S.Y., Leung N.E.L.S.O.N., Wang N.I.N.G.L.I., Tang S.W., Lee T.M.C. and So K.F., The roles of paroxetine and corticosterone on adult mammalian retinal ciliary body cell proliferation, The Chinese Medical Journal. 2010, 123: 1305-1310.

Yau S.Y., Lau W.M., Tong J., Wong R., Ching Y.P., Qiu G., Tang S.W., Lee T.M.C. and So K.F., Hippocampal cytogenesis and dendritic plasticity support running-enhanced memory and depression behavior, Proceedings of the International Anatomical Sciences and Cell Biology Conference, May 26-29, 2010. 37.

Yau S.Y., Lau W.M., Tong J., Wong R., Ching Y.P., Qiu G., Tang S.W., Lee T.M.C. and So K.F., Hippocampal cytogenesis and dendritic plasticity support running-enhanced memory and depression behaviour in stressed rat, The 4th Beijing International Forum on Rehabilitation, Oct. 28-30, 2009. 6-7.

Researcher : Tay DKC

List of Research Outputs

Ellis-Behnke R.G., Liang Y., Cheung W.H. and Tay D.K.C., Controlling The Growth And Differentiation Of Cells With Physical Interaction, Nanobiotech 2009.

Ellis-Behnke R.G., Liang Y., Guo J., Tay D.K.C., Schneider G.E., Teather L.A., Wu W. and So K.F., Forever young: how to control the elongation, differentiation and proliferation of cells using nanotechnology, Cell Transplantation. 2009.

Ellis-Behnke R.G., Cheung W.H., Liang Y. and Tay D.K.C., Nanoscale Image Contrast Agents To Enhance The Visualization Of Regenerating Cns Axons, Presidential Symposium on Nanotechnology at the 51st Meeting of the American Society for Therapeutic Radiology and Oncology (ASTRO). 2009.

Ellis-Behnke R.G., Liang Y., Cheung W.H., So K.F., Wu W. and Tay D.K.C., Redefining tissue engineering for nanomedicine: Visualizing the progress of regenerating axons in the mammalian visual system after complete transection and treatment with self-assembling nanomaterial, 6th Annual World Congress for Brain Mapping and Image Guided Therapy, Harvard Medical School, Boston MA. 2009.

Ellis-Behnke R.G., Cheung W.H., Tay D.K.C., Liang Y., Lui Kau K.W.F., Schneider G.E. and So K.F., The control of stem cells in the brain and spinal cord by extracellular nanomatrix system, Society for Neuroscience, Chicago. 2009.

Ellis-Behnke R.G., Liang Y., Cheung S.W.H., So K.F. and Tay D.K.C., Using a self-assembling nanopeptide to achieve ocular hemostasis without causing clotting or secondary inflammation, ARVO 2010. Program No. 427, Poster No. D1131.

Ellis-Behnke R.G., Liang Y., Cheung W.H. and Tay D.K.C., Using nanotechnology to control the elongation, differentiation and proliferation of cells, 16th Annual Optic Nerve Rescue and Restoration Think Tank. 2009.

So K.F., Liang Y., Tay D.K.C. and Ellis-Behnke R.G., Nanomedicine for CNS regeneration and instant hemostasis, WACBE World Congress on Bioengineering 2009, July 26-26, 2009, Hong Kong. 2009, 4.

Yuan T., Liang Y., Tay D.K.C., So K.F. and Ellis-Behnke R.G., Olfactory tract transection enhances adult neurogenesis in piriform cortex, 22nd Biennial Meeting of the International Society of Neurochemistry, Busan Korea. 2009.

Researcher : Tipoe GL

Project Title:	A voluntary oral ethanol-feeding rat model associated with steatohepatitis
Investigator(s):	Tipoe GL
Department:	Anatomy
Source(s) of Funding:	Small Project Funding
Start Date:	01/2008
Completion Date:	04/2010

Abstract:

A variety of animal models used in the study of alcoholic liver disease (ALD) reflects the formidable task of developing a suitable model that replicates the human prototype. Each animal model emphasizes one or more of the features seen in humans (Nanji and French, 2003). The development of the intragastric tube feeding model (IG) providing ethanol and liquid diet led to a significant advance in the understanding of the pathological and biochemical mechanisms leading to alcohol-induced liver injury (Nanji et al., 1989; Morimoto et al., 1995; Tsukamoto, 1998). Several pathogenic mechanisms have been identified that are important in alcoholic liver injury (Nanji et al., 2002; Nanji, 2003) Among the pathogenic mechanisms that have been extensively studied in the intragastric feeding model include endotoxemia and oxidative stress (Nanji and French, 2003). One factor that might link endotoxemia, oxidative stress and liver injury is nuclear-factor kappa B (NF-kB) (Barnes and Karin, 1997; Ghosh et al., 1998). NF-kB can stimulate a variety of genes including those important in ALD. They include tumor necrosis factor alpha (TNF-alpha), cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS), all of which are expressed in ethanol-fed rats exhibiting necro-inflammatory changes. Elevated levels of cytochrome P450 2E1 (CYP2E1) contribute to oxidative stress in ethanol-fed animals (Caro and Cederbaum, 2004; Cederbaum, 2001). Oxidative stress is also believed to lead to a decrease in proteasome activity (Donohue et al., 2004). Additionally, multiple aspects of receptor mediated endocytosis are also impaired in the intragastrically ethanol-fed rats (Casey et al., 2004). The purpose of the present study is to compare whether the pathological and biochemical changes in a newly-developed voluntary oral ethanol-feeding model are comparable to those seen in the intragastric feeding rat model. We took advantage of our previous results and those of others that show that rats fed fish oil-ethanol diets develop severe liver injury and that females are more susceptible than males. References: Barnes PJ, Karin M. (1997) New England Journal of Medicine 336(15): 1066-71. Caro AA, Cederbaum AI. (2004) Free Radical Biology Medicine 36(10): 1303-16. Casey CA, McViker BC, Donohue TM jr, McFarland MA, Wiegert RL, Nanji AA. (2004) Journal of Applied Physiology 96(1): 76-80. CederbaumAI (2001) Free Radical Biology Medicine 31(12): 1524-6. Donohue TM jr, Kharbanda KK, Casey CA, Nanji AA. (2004) Alcohol Clinical and Experimental Research 28(8): 1257-63. Ghosh S, May MJ, Kopp EB. (1998) NF-kappa B and Rel proetiens: evolutionary conserved mediators of immune responses. Annual Review of Immunlogy 16: 225-60. Nanji AA, Tsukamoto H, French SW (1989) Experimental Molecular Pathology 51(2): 141-48. Nanji AA, Su GL, Laposata M, French SW. (2002) Alcohol Clinical Experimental Research 26(5): 731-6. Nanji AA. Jokelainen K, Tipoe GL, Rahemutulla A, Thomas P, Danneberg AJ. (2003) American Jpurnal of Physiology Gastrointestinal Liver Physiology 284(2): G321-7. Nanji AA, French SW (2003) Alcohol Research Health 27(4):325-30. Morimoto M, Hagbjork, AL, Wang YJ, Fu PC, Clot P, Albano E, Ingelman-Sandberg M, French SW. (1995) Hepatology 21(6): 1610-7.

Project Title:	Voluntary Oral Feeding of Rats Not Requiring a Very High Fat Diet is a Clinically Relevant Animal Model of Non-Alcoholic Fatty Liver Disease (NAFLD)
Investigator(s):	Tipoe GL
Department:	Anatomy
Source(s) of Funding:	Small Project Funding
Start Date:	01/2009

Abstract:

The aim of the present study is to produce a clinically relevant animal model of non-alcoholic fatty liver disease (NAFLD) not requiring a high fat diet through voluntary oral feeding. Existing animal models for the study of NAFLD are usually either genetically altered animals or fed with a diet that is extremely high in fat or carbohydrates. Generally, two feeding methods are employed in animal models; voluntary and intragastric. Intragastric rat feeding models have contributed to a greater understanding of alcoholic liver disease (Nanji et al., 2001,) and more recently in non-alcoholic fatty liver disease (Zou et al., 2006). A voluntary route of consumption of diet instead is the preferred means of food intake because it requires no special training and additional technical equipment. Ad libitum consumption of diet, however, tends to be self-limiting either because of the diet composition or palatability (Maegawa et al., 1986; Lieber et al., 2004). This is contrary to what is observed in the clinical setting where over indulgence in eating is the usual occurrence and therefore, obesity is usually the end result. Some investigators, however, have found it difficult to induce obesity in normal rats using a high fat diet fed ad libitum (Pedersen et al., 1991). Nevertheless, some studies were successful in showing features of development of non-alcoholic fatty liver disease (NAFLD), employing a diet with a content of more than 70 percent of fat. This fat is very different from what is described as a “westernized diet”. (Lieber et al., 2004; Zou et al., 2006). To be able to develop a NAFLD animal model that can simulate the conditions similar to the human liver disease would provide a significant break through in verifying some of the important suspected mechanims/factors that promote the progression of steatohepatitis to a a full blown NAFLD. References: 1. Lieber C.S., Leo M.A., Mak K.M., Xu Y., Cao Q., Ren C., Ponomarenko A. and DeCarli L.M. (2004). Model of nonalcoholic steatohepatitis. Am. J. Clin. Nutr. 79(3):502-9. 2. Maegawa H., Kobayashi M., Ishibashi O., Takata Y. and Shigeta Y. (1986). Effect of diet change on insulin action: difference between muscles and adipocytes. Am. J. Physiol. 251(5 Pt 1):E616-23. 3. Nanji A.A., Jokelainen K., Tipoe G.L., Rahemtulla A. and Dannenberg A.J. (2001). Dietary saturated fatty acids reverse inflammatory and fibrotic changes in rat liver despite continued ethanol administration. J. Pharmacol. Exp. Ther. 299(2):638-44. 4. Pedersen O., Kahn C.R., Flier J.S., Kahn B.B. (1991). High fat feeding causes insulin resistance and a marked decrease in the expression of glucose transporters (Glut 4) in fat cells of rats. Endocrinology. 129(2):771-7. Watarai T., Kobayashi M., Takata Y., Sasaoka T., Iwasaki M. and Shigeta Y. (1988). Alteration of insulin-receptor kinase activity by high-fat feeding. Diabetes. 37(10):1397-404. 5. Zou Y., Li J., Lu C., Wang J., Ge J., Huang Y., Zhang L. and Wang Y. (2006). High-fat emulsion-induced rat model of nonalcoholic steatohepatitis. Life Sci. ;79(11):1100-7.

Project Title:	Green Tea Polyphenols Attenuates the severity of oxidative stress and inflammation in Non-Alcoholic Liver Disease (NAFLD) in Rats
Investigator(s):	Tipoe GL
Department:	Anatomy
Source(s) of Funding:	Small Project Funding
Start Date:	01/2010

Abstract:

The main aim of this present study is to determine whether green tea polyphennols, particularly its active component epigallocathechins gallate (EGCG), could reduce the level of oxidative stress and inflammation in a non-alcoholic fatty liver disease (NAFLD) rat model. Recently, we have developed a clinically relevant and orally fed rat model for the study of NAFLD (Tipoe et al., 2009). These rats showed moderate to severe steatohepatitis and necroinflammation similar to those observed in clinical cases. The rat model also showed evidence of oxidative stress. We propose to test the efficacy of EGCG in attenuating the degree of chronic liver injury in our NAFLD rat model. Reference: Tipoe GL, Ho CT, Liong EC, Leung TM, Lau TYH, Fung ML, Nanji AA. (2009). Voluntary oral feeding of rats not requiring a very high fat diet is clinically relevant animal model of non-alcoholic fatty liver disease (NAFLD). Histol Histopathol, 24, 1161-1169.

List of Research Outputs

Chan L.K. and Tipoe G.L., Training of professionalism in first year medical students’ encounter with cadavers, The 7th Asian Pacific Medical Education Conference, 6-7 February 2010.

Lau C.F., Ng K.M., Tipoe G.L. and Fung M.L., Chronic intermittent hypoxia induces oxidative stress and decreases NO production in the carotid artery of rats. The 13^th Annual Scientific Meeting of the Institute of Cardiovascular Science and Medicine, P16, 12/2009, (Journal of the Hong Kong College of Cardiology). 2009, 17(2):61.

Lau C.F., Hung M.W., Ng K.M., Tipoe G.L. and Fung M.L., Oxidative injury and inflammation in the lung of rats exposed to chronic intermittent hypoxia, Physiology Symposium 2009, HKU,Hong Kong 5/2009.

Tipoe G.L., Leung T.M., Liong E.C., Lau T.Y.H., Fung M.L. and Nanji A.A., Epigallocatechin-3-gallate (EGCG) reduces liver inflammation, oxidative stress and fibrosis in carbon tetrachloride (CCl₄)-induced liver injury in mice, Toxicology. 2010, 273: 45-52.

Tipoe G.L., Ho M.C.T., Liong E.C., Leung T.M., Lau T.Y.H., Fung M.L. and Nanji A.A., Voluntary oral feeding of rats not requiring a very high fat diet is a clinical relevant model of non-alcoholic fatty liver disease (NAFLD), Histology and Histopathology. 2009, 24(9): 1161-1169.

Researcher : Tong J

List of Research Outputs

Yau S.Y., Lau W.M., Tong J., Ching Y.P., Lee T.M.C. and So K.F., Hippocampal cell proliferation and dendritic enrichment is essential for beneficial effects of exercise on stressed animal model, Hellenic Society for Neuroscience, 23rd Annual Meeting, September 13-14, 2009, Greece.. 2009, 78-79.

Yau S.Y., Lau W.M., Tong J., Wong R., Ching Y.P., Qiu G., Tang S.W., Lee T.M.C. and So K.F., Hippocampal cytogenesis and dendritic plasticity support running-enhanced memory and depression behavior, Proceedings of the International Anatomical Sciences and Cell Biology Conference, May 26-29, 2010. 37.

Yau S.Y., Lau W.M., Tong J., Wong R., Ching Y.P., Qiu G., Tang S.W., Lee T.M.C. and So K.F., Hippocampal cytogenesis and dendritic plasticity support running-enhanced memory and depression behaviour in stressed rat, The 4th Beijing International Forum on Rehabilitation, Oct. 28-30, 2009. 6-7.

Researcher : Tsang CM

Project Title:	Investigating the role of Epstein-Barr virus (EBV) in the development of nasopharyngeal carcinoma (NPC): regulation of survivin by EBV encoded latent membrane protein (LMP)1 under starvation stress
Investigator(s):	Tsang CM, Tsao GSW
Department:	Anatomy
Source(s) of Funding:	Small Project Funding
Start Date:	10/2009

Abstract:

Background: Nasopharyngeal carcinoma (NPC) is common among Southern Chinese including the Hong Kong population (3). Epstein-Barr virus (EBV) infection is closely associated with NPC (4). EBV is known to be an oncogenic virus as its encoded latent genes, e.g. LMP1, LMP2A etc., have been shown to facilitate or initiate tumorgenic transformation (13). EBV is highly associated with nasopharyngeal carcinoma, presence of EBV genome can be detected in near all, if not all tumour cells (9). It has been postulated that EBV is involved in the development and progression of NPC. However, the number of studies conducted on EBV infection in nasopharyngeal epithelial cell lines is few compared to B-cell lines. Nasopharyngeal epithelial cells do not express the specific receptor (CR-2) for EBV. In vitro EBV infection rate on NP cell lines is usually less than 0.1% which hampers the investigation of the role of EBV in this cell type. More extensive works were only done by expressing individual EBV latent genes on epithelial cell lines. Therefore, establishment of EBV infection cell model using NP epithelial cells is crucial to understand events related to EBV infection and regulatory control of its gene expression. On the other hand, clonal EBV genome can be detected in invasive carcinomas and high-grade dysplastic lesions indicating that EBV infection is an early event and may precede the expansion of the malignant cells (10). Therefore, to elucidate the transformative functions of EBV in the early pathologenesis of nasopharyngeal carcinoma, infection of EBV to representative premalignant cell model is essential. What we have done (preliminary data attached) A. Establishment of EBV infected premalignant and cancer NP cell lines by coculturing with EBV producing B-cell line Recently, it has been reported that EBV infection to epithelial cell could be enhanced by co-culturing with EBV-infected B-cells. We have adopted this co-culture method of infection, and successfully infected two NP cell lines with recombinant EBV tagged with GFP (Fig 1). One cell line is telomerase immortalized nasopharyngeal epithelial cells, NP460hTert. The NP460hTert cells are non-malignant in nature as indicated by their lack of anchorage independent growth in soft agar assay and non-tumourigenicity when injected into nude mouse (8); the other is a cancer cell line derived from NPC, HK1. Both of them express EBV encoded genes EBER, EBNA1, LMP1 etc. resembling the expression pattern that can be found in NPC in vivo (Fig 2). B. EBV infected cells were more resistant to nutrient insufficiency When EBV infected NP460hTert and HK1 cells were grown in full-supplemented or serum-added medium, both of them did not have any growth advantage when compared to their non-infected counterparts (Fig 3). We then speculated ischemia is the in vivo selection force for EBV infected premalignant epithelial cells to undergo transformation. Tumour growth in vivo is known to be under ischemic conditions, i.e. inadequate supply of nutrients and oxygen due to insufficient supply of blood. To examine whether EBV infection may confer resistance to starvation, the growth factor-supplemented medium for EBV-infected and non-infected NP460hTert cells was replaced with serum-free RPMI and examined for differences in growth properties. Interestingly, the NP460hTert-EBV cells could endure better than the non-infected cells under nutrient-insufficiency, and easily recovered from the starvation condition once growth factor-supplemented medium was restored in culture (Fig 4). C. Colony formation of EBV infected NP460hTert cells under starvation stress To examine the ability of EBV infected NP460hTert cells to sustain viability under nutrient deficiency, we plated the EBV infected and uninfected NP460hTert cells at low cell density and did not change the culturing medium for 3 weeks. Interestingly, viable and proliferative cell clones were only found in EBV-infected NP460hTert but not in control uninfected-NP460hTert cells which strongly indicating the ability of EBV infected NP460hTert cells to withstand starvation and sustain viability during harsh conditions (Fig 5). D. EBV infected cells were resistant to starvation-induced apoptosis To further understand the mechanism involved in the resistance of EBV infected cells under starvation stress, we cultured the EBV infected NP460hTert cells in Earle’s balanced salt solution and collected protein for Western blot analysis. We found that the NP460hTert-EBV cells expressed much lower level of apoptotic markers (cleaved PARP and cleaved caspase 3) when compared to non-infected cells (Fig 6). Survival marker (pAkt) could also be substained. Suppressed apoptosis could also be observed when the cells were under prolonged starvation by culturing the cells without changing medium for 2 week. Both EBV infected NP460hTert and HK1 cells were shown to have suppressed starvation-induced apoptosis (Fig 7). E. EBV encoded LMP1 was found to be upregulated under starvation stress To find out which EBV encoded gene was responsible for the resistance of starvation induced apoptosis, EBV infected NP460hTert and HK1 were cultured in Earle’s Balanced salt solution and RNA were extracted under different time points. We found that LMP1, but not other EBV encoded genes (EBERs and LMP2A) were upregulated using semi-quantitative RT-PCR (Fig 8). F. Enhanced survivin expression in EBV infected cells under starvation As to further delineate the mechanism for the starvation resistance of EBV infected cells, we detected the expression of survivin under starvation. Survivin is a member of the inhibitor of apoptosis (IAP) family. The survivin protein functions to inhibit caspase activation therefore leading to negative regulation of apoptosis. It has been reported that survivin can suppress starvation-induced apoptosis (7, 12) while it is also a down-stream effector of LMP1 (1, 6). We found that survivin was upregulated in EBV infected NP460hTert cells under starving condition (Fig 9). Our hypothesis: Our preliminary data has shown that EBV infection could confer survival advantage under nutrient insufficiency. We have further observed EBV infected cells could resist starvation induced-apoptosis while survivin and LMP1 expression were upregulated. Survivin has been consistently identified as a risk-associated gene in various malignancies, carrying unfavorable implications for cancer prognosis, disease recurrence and survival (2, 5). The differential expression of survivin in nearly every human tumor, as compared with normal tissues, has demonstrated its broad exploiting function for tumor maintenance, and perhaps multiple aspects of tumorigenesis, from initiation to metastasis. It was noted that survivin upregulation was observed in similar in vitro starving condition that we did on the EBV infected cells (12), demonstrating survivin may be the prime EBV targeting protein for exhibiting the anti-apoptosis effect in EBV infected cells under nutrient insufficiency. On the other hand, previous publications have shown LMP1 can regulate expression of survivin and thus contributing to enhanced proliferation and apoptosis inhibition (1). Therefore, we speculate that EBV infection could confer resistance to starvation induced apoptosis through survivin expression under the regulatory effect of LMP1. Objectives: 1. To confirm survivin is the effector protein responsible for the resistance of starvation induced-apoptosis in EBV infected cells. 2. To investigate the regulatory role LMP1 in survivin expression under starvation. 3. To examine the clinical significance of survivin by detecting the expression of survivin in in vivo systems and NPC biopsies.

List of Research Outputs

Hong B., Lui V.W.Y., Hui E.P., Ng M.H.L., Cheng S.H., Sung F.L., Tsang C.M., Tsao G.S.W. and Chan A.T.C., Hypoxia-trageting by tirapazamine (TPZ) induces preferential growth inhibition of nasopharyngeal carcinoma cells with Chk1/2 activation, Invest New Drugs. 2009, 21.

Lui V.W.Y., Lau C.P.Y., Cheung C.S.F., Ho K., Ng M.H.L., Cheng S.H., Hong B., Tsao G.S.W., Tsang C.M., Lei K.I.K., Yamasaki Y., Mita A. and Chan A.T.C., An RNA-directed nucleoside anti-metabolite, 1-(3-C-ethynyl-beta-D-ribo-pentofuranosyl)cytosine (ECyd), elicits antitumor effect via TP53-induced glycolysis and apoptosis regulator (TIGAR) downregulation, Biochemical Pharmacology. 2010, 79: 1772-1780.

Lui V.W.Y., Yau D.M.S., Wong E.Y.L., Ng Y.K., Lau C.P.K., Ho Y., Chan J.P.L., Hong B., Ho K., Cheung C.S., Tsang C.M., Tsao G.S.W. and Chan A.T.C., Cucurbitacin I elicits anoikis sensitizaton, inhibits cellular invasion and in vivo tumor formation ability of nasopharyngeal carcinoma cells, Carcinogenesis. 2009, 30(12): 2085-2094.

Tsang C.M., Lau P.W.E., Di K., Cheung P.P.Y., Hau P.M., Ching Y.P., Wong Y.C., Cheung A., Wan T.S.K., Tong Y., Tsao G.S.W. and Feng Y., Berberine inhibits Rho GTPases and cell migration at low doses but induces G2 arrest and apoptosis at high doses in human cancer cells, International Journal of Molecular Medicine. 2009, 24: 131-138.

Tsang C.M., Zhang G., Seto E., Takada K., Deng W., Yip Y.L., Man C.W.Y., Hau P.M., Chen H., Cao Y., Lo K.W., Middeldorp J.M., Cheung A. and Tsao G.S.W., Epstein-Barr virus infection in immortalized nasopharyngeal epithelial cells: Regulation of infection and phenotypic characterization. , International Journal of Cancer. 2010, 127: 1570-1583.

Tsang C.M., Zhang G., Seto E., Takada K., Deng W., Yip Y.L., Man C.W.Y., Hau P.M., Cao Y., Lo K.W. and Middeldorp J.M., Epstein-Barr virus infection in immortalized nasopharyngeal epithelial cells: Regulation of infection and phenotypic characterization, Int. J. Cancer. 2010, 127: 1570-83.

Tsao G.S.W., Tsang C.M., Zhang G., Deng W., Hau P.M., Man C.W.Y., Kenzo T., Chen H., Yip Y.L., Lo K.W., Cao Y. and Cheung A., Epstein-Barr virus infection confer stress-resistant property in immortalized nasopharyngeal epithelial cells., Proceedings of American Association of Cancer Research. 2010.

Wong J.H.T., Lui V.W.Y., Umezawa K., Ho Y., Wong E.Y.L., Ng M.H.L., Cheng S.H., Tsang C.M., Tsao G.S.W. and Chan A.T.C., A small molecule inhibitor of NF-kB, dehydroxymethylepoxyquinomicin (DHMEQ), suppresses growth and invasion of nasopharyngeal carcinoma (NPC) cells, Cancer Letters. 2010, 287: 23-32.

Wong S.T.S., Man O.Y., Tsang C.M., Tsao G.S.W., Tsang R.K.Y., Chan Y.W., Ho W.K., Wei W.I. and To V.S.H., Microrna Let-7 Suppresses Nasopharyngeal Carcinoma Cells Proliferation Through Downregulating C-myc Expression, Journal of Cancer Research and Clinical Oncology. Berlin, Springer Berlin / Heidelberg, 2010.

Yip Y.L., Tsang C.M., Jin Y., Deng W., Man C.W.Y., Cheung P.P.Y., Chen H., Cheung A. and Tsao G.S.W., The Epstein-Barr virus-encoded LMP1 extended the life span and immortalized nasopharyngeal epithelial cells., Hong Kong International Cancer Congress . 2009.

Researcher : Tsang CM

List of Research Outputs

Researcher : Tsao GSW

Project Title:	Mechanisms involved in Id1 induced centrosome abnormalities
Investigator(s):	Tsao GSW, Wong YC
Department:	Anatomy
Source(s) of Funding:	General Research Fund (GRF)
Start Date:	09/2006
Completion Date:	08/2009

Abstract:

(1) To examine and confirm the involvement of Aurora A expression and NFkB in Id1 induced centrosome abnormalities in cells. (2) To elucidate the events involved in the actigvation of NFkB by Id1.

Project Title:	Mechansims involved in the induction of chromosome instability by the Epstein Barr virus encoded LMP1 protein.
Investigator(s):	Tsao GSW, Cheung A, Chow BKC, Lo KW
Department:	Anatomy
Source(s) of Funding:	General Research Fund (GRF)
Start Date:	10/2007

Abstract:

To elucidate the signaling pathways involved in the induction of chromosome instability by LMP1; to examine the mechanism involved in RASSFIA downregulation induced by LMP1; to define the mitotic events involved in LMP1-induced chromosome instability by live cell imaging study.

Project Title:	Mechanisms involved in the inhibition of DNA damage response in EBV infected nasopharyngeal epithelial cells
Investigator(s):	Tsao GSW
Department:	Anatomy
Source(s) of Funding:	Small Project Funding
Start Date:	01/2008
Completion Date:	12/2009

Abstract:

EBV infection is closely associated with the pathogenesis of nasopharyngeal carcinoma (NPC) and has been postulated as an important etiological agent of NPC. EBV could immortalize B cells in vitro and oncogenic property has been demonstrated in some of the EBV encoded genes such as LMP1. The pathogenic role of EBV in NPC remains enigmatic as EBV infection is ubiquitous and yet NPC is commonly seen among southern Chinese but not in western population. EBV readily infects B cells but not normal nasopharyngeal epithelial cells. There are reports showing that genetic alterations may be present in the nasopharyngeal epithelium of high risk NPC population (Cantonese) which renders these cells to become susceptible to EBV infection. The study of EBV infection in NPC development is greatly hampered by the lack of representative cell models. Our laboratory has recently established the first telomerase-immortalized nasopharyngeal epithelial cell line (NP460hTert) which harbors genetic alteratioins present in premalignant and cancerous nasopharyngeal epithelial cells, namely, p16 and RASSF1A inactivation (Li HM et al., International Journal of Cancer, 2006). The NP460hTert may represent a premalignant nasopharyngeal epithelial cell model for EBV infection study. Recently, EBV infection has been achieved for the first time in this premalignant nasopharyngeal epithelial cell line. Interestingly, we observed that EBV infected NP460hTert is resistance to apoptotic induction upon treatment with DNA damage response such as Cis-platinum. This has prompted us to investigate if EBV infectin may suppress the DNA damage responses in infected host cells. EBV has been recently postulated to affect mitosis and induce chromosomal aberrations in cells. Mitotic defects will generally induce DNA damage responses to arrest cell growth. We would like to examine if EBV infection may suppress DNA damage response to support survival of the mitotic dysregulated cells . This would result in the generatin of aneuploidy in EBV infected cells. Aneuploidy has been shown to facilitate the carcinogenesis process. The study of this mechanism will greatly enahnce our standing of tumorigenic transformation in EBV infected premalignant nasopharyngeal epithelial cells. Lastly, the identity of EBV genes involved in the suppression of DNA damage response is unclear. We would propose to investigate the effects of some of the potential EBV encoded genes in their ability to suppress DNA damage response using gene expression methods. Specific obectives are: 1. To define the signal pathways involved in the inhibition of DNA damage response induced by EBV in nasopharyngeal epithelial cells 2. To investigate the significance of inhibition of DNA damage response and mitotic dysregulation induced by EBV in nasopharyngeal epithelial cells 3. To identify the potential EBV encoded genes involved in inhibition of DNA damage response in nasopharyngeal epithelial cells.

Project Title:	Cancer
Investigator(s):	Tsao GSW, Poon RTP
Department:	Anatomy
Source(s) of Funding:	Seed Funding for Strategic Research Theme
Start Date:	11/2008
Completion Date:	10/2011

Abstract:

n/a

Project Title:	Cancer
Investigator(s):	Tsao GSW, Poon RTP
Department:	Anatomy
Source(s) of Funding:	Seed Funding for Strategic Research Theme
Start Date:	11/2008

Abstract:

n/a

Project Title:	The role of TGF-beta in EBV infection and pathogenesis of nasopharyngeal carcinoma
Investigator(s):	Tsao GSW, Lan HY
Department:	Anatomy
Source(s) of Funding:	Small Project Funding
Start Date:	01/2009

Abstract:

Nasopharyngeal carcinoma (NPC) is common among southern Chinese living in Hong Kong and southern provinces of China. Epstein-Bar virus (EBV) infection is believed to play an etiological role in the pathogenesis of NPC. While EBV readily infects human B cells both in vitro and in vivo, infection of EBV in nasopharyngeal epithelium is rather inefficient. Nonetheless, EBV infection could be detected in most if not all nasopharyngeal carcinoma and an etiological role of EBV infection in NPC development has been postulated. Expression of multiple EBV genes, notably those expressed during latent infection, has been shown to be oncogenic and may transform premalignant nasopharyngeal epithelial cells into cancer cells. EBV infection in NPC is a clonal event and is believed to occur at an early stage of NPC development. The host factors regulating EBV infection and the EBV infection cycle as well as expression of the EBV genes are largely unknown. The route of EBV infection and the factors regulating EBV infection remains enigmatic and poorly defined. Using a direct cell-cell interaction method involving co-culturing of EBV producing cells and target epithelial cells, EBV infection of primary epithelial cells could be achieved at a low but significant efficiency (few percentage). In our laboratory, we have established primary culture of nasopharyngeal epithelial cells and several immortalized nasopharyngeal epithelial cells system and have successfully infected them with EBV by co-culture methods. The mucosa of human nasopharyngeal epithelium is heaviliy infiltrated with inflammatory cells. The inflammatory cells, as well as the epithelial cells undergoing malignant changes, produce multiple inflammatory cytokines. The role of these inflammatory cytokines in EBV infection and tumorigenic transformation of premalignant nasopharyngeal epithelial cells are largely unknown. Using the cell-cell co-culture methods, we have examine the effects of multiple inflammatory cytokines, including TGF-beta, TNFalpha, IL6, and IL10, on EBV infection into primary, premalignant and malignant human nasopharyngeal epithelial cells. All of these inflammatory cytokines have been previously identified to be present in the stroma of nasopharyngeal carcinoma. Their roles on EBV infection on nasopharyngeal epithelial cells and tumorigenic potentials are unknown. Among the various inflammatoryu cytokines examined, we observed that TGF-beta has profound effects on EBV entry into premalignant nasopharynageal epithelial cells. In addition, TGF-beta could also reactivate lytic infection of EBV in EBV-infected premalignant nasopharyngeal epithelial cells. Inflammation is commonly observed in nasopharyngeal mucosa particularly when there are premalignant changes. We postulates that inflammatory cytokines present in the stroma may facilitate EBV entry and infection into premalignant nasopharynageal epithelial cells. While some of the cytokines such as IL6 may activate STAT3 to maintain latent EBV infection, the TGF-beta may stimulate lytic infection. TGF-beta could induce lytic infection of EBV in B cells. The influence of TGF-beta on EBV human nasopharyangeal epithelial cells are largely unexplored. There are several reports indicating that lytic infection of EBV and expression of multiple lytic EBV genes could induce DNA damage, mitotic dysregulation and apoptosis in EBV infected cells. In human nasopharyangel epithelial cells, EBV infection is abortive in nature, meaning that the lytic infection cycle of EBV is not complete and infectious vial particles are not produced. Expression of lytic EBV genes may however, induce genetic alterations in normal primary epithelial cells and induced cellular apoptosis. The premalignant nasopharyngeal epithelial cells may have a lower response to DNA damages, and DNA damage induced by lytic genes of EBV may be tolerated and retained. Hence chronic stimulation of lytic EBV infection may induce DNA damages and facilitate tumorigenesis in premaliganant nasopharyngeal epithelial cells. Using our established EBV infected nasopharyngeal epithelial cell models, we will examine the underlying mechanism involved in TGF-beta facilitated EBV infection into premalignant nasopharyngeal epithelial cells and the tumorigenic potential of TGF-beta on premalignant nasopharyngeal epithelial cells . Specifically, we will examine the cell signaling pathways of TGF-beta activation nvolved in EBV infection. The role of TGF-beta in the regulation of latent and lytic infection of EBV infection in EBV infection nasopharyangeal epithelial cells are largely unknown and will be examined. The long effects of activation of TGF-beta in malignant transformation of premalignant nasopharyngeal epithelial cells will also be explored. Specific objectives of this study are: (1)To define the mechanisms involved in the regulation of EBV infection in nasopharyngeal epithelial cells by TGF-betat. (2)To examine the role of TGF-beta in regulating latent and lytic infection of EBV in premaliganant nasopharyngeal cell models (3)To examine the tumorigenic potential of TGF-beta in EBV infected premalignant nasopharyangeal cell model.

Project Title:	The role of STAT activation in regulating persistence of EBV infection in premalignant nasopharyngeal epithelial cell model
Investigator(s):	Tsao GSW, Chen H, Lo KW
Department:	Anatomy
Source(s) of Funding:	General Research Fund (GRF)
Start Date:	01/2009

Abstract:

(1) Live cell imaging of the involvement of STAT3 and STAT5 activation in EBV infection in nasopharyngeal epithelial cells; (2) To define the role of STAT3 and STAT5 activation in the regulation of EBV infection in nasopharyngeal epithelial cells; (3) To determine the role of stromal cytokines (IL6 and TGFbeta) in regulation of latent infection and persistence of EBV in nasopharyngeal epithelial cells.

Project Title:	The impact of Bmi-1 expression on mitosis and cancer
Investigator(s):	Tsao GSW, Zeng M
Department:	Anatomy
Source(s) of Funding:	General Research Fund (GRF)
Start Date:	07/2009

Abstract:

1) To examine the involvement of Bmi-1 in mitosis by live cell imaging; 2) To examine the role of Bmi-1 as a binding partner of Aurora B kinase; 3) To investigate the underlying mechanisms involved in the increase of Aurora B kinase levels in Bmi-1 expressing cells.

Project Title:	Regulation of Epstein-Barr virus infection in nasopharyngeal epithelial cells
Investigator(s):	Tsao GSW, Chen H
Department:	Anatomy
Source(s) of Funding:	Small Project Funding
Start Date:	01/2010

Abstract:

GENERAL BACKGROUND Nasopharyangeal carcinoma (NPC) is a common cancer in Hong Kong and Guangdong province. The disease is closely associated with EBV infection. Several EBV encoded proteins have been shown to have oncogenic potentials1. EBV infection could be detected at the early stage of NPC development. The current hypothesis of pathogenesis of NPC is that EBV infection of premalignant nasopharyngeal epithelium harbor genetic alterations and transform it into cancerous tissue. Stromal inflammation has been shown to play an important role in infection-associated cancers. The contribution of stromal inflammtion to NPC carcinogenesis is unclear at this stage. The study of EBV infection and NPC carcinogenesis has been hampered by the lack of representative premalignant nasopharynageal cell models and the difficulty to infect human epithelial cells by EBV. Several recent advances have enabled us to examine this important aspect of NPC carcinogenesis: (a) the advances in cell immortalization techniques which contributes to the generation of premalignant nasopharyngeal cell models for EBV infection study; (b) establishment of an efficient infection protocol of EBV into human epithelial cells; (c) the availability of recombinant EBV harbouring GFP protein which facilitate monitoring of EBV-infected nasopharyngeal epithelial cells. We have recently examine the effects of inflammatory cytokines in regulating EBV infection in our immortalized nasopharyngeal epithelial cell system and identified the TGF-beta is an effective cytokine which support EBV infection in nasopharyngeal epithelial cells. In this study, we propose to examine the role of TGF-beta in the regulating of EBV infection. KEY ISSUES IDENTIFIED EPSTEIN-BARR VIRUS (EBV) INFECTION IS CLOSELY ASSOCIATED WITH NASOPHARYNGEAL CARCINOMA (NPC) Epstein-Barr virus (EBV) is believed to play an important role in the pathogenesis of nasopharyngeal carcinoma (NPC). Infection of EBV into nasopharyngeal epithelial cells occurs at an early stage of NPC development. Expression of EBV genes may drive the malignant transformation of premalignant nasopharyngeal epithelial cells. EBV INFECTION READILY INFECTS B LYMPHOCYTES BUT NOT NASOPHARYNGEAL EPITHELIAL CELLS In great contrast to the ease of EBV infection into B lymphocytes, EBV infection into nasopharyngeal epithelial cells is difficult and uncommon in normal nasopharyngeal epithelium. Nonetheless, EBV infection into premalignant nasopharyngeal epithelial cells is believed to constitute an important step in the development of NPC. Elucidation of the mechanisms of EBV infection into nasopharyngeal epithelial cells will shed lights to the pathogenesis of NPC. EBV INFECTION COULD BE ACHIEVED BY CELL-CELL CONTACT WITH EBV-PRODUCING B CELLS. EBV infects human B lymphocytes through the binding of CR2 receptor which is expressed in all B lymphocyte surfaces but not in nasopharyngeal epithelial cells. Recent studies have shown that EBV infection of human epithelial cells requires close contact of EBV-producing B cells with the epithelial cells. Our laboratories have pioneered the establishment of immortalized nasopharyngeal epithelial cells for EBV infection and NPC studies. Recently, using primary culture and immortalized non-malignant nasopharyngeal epithelial cells established in our laboratories, we have been able to achieve EBV infection in these cells (Tsao et al., BBA, 2000; Li HM et al., IJC, 2006; Lo et al., Neoplasia, 2006, Choy et al., J Exp. Med, 2008). PRETREATMENT OF NASOPHARYNGEAL EPITHELIAL CELLS WITH TGF-BETA INCREASED THE RATE OF EBV INFECTION BY SEVERAL FOLDS The rate of EBV infection is highly variable among the different nasopharyngeal epithelial cell lines. The differentiation status and cell signaling properties of the nasopharyngeal epithelial cells are suspected to play major roles in regulating the susceptibility of these cells to EBV infection. We hypothesize that inflammation and secretion of cytokines by the inflammatory cells in the nasopharyngeal mucosa may play an important role in EBV infection. Pretreatment of cells with various cytokines could influence the EBV infection rate into immortalized nasopharyngeal epithelial cells (Tsao SW et al., unpublished observations). Interestingly, pretreatment of nasopharyngeal epithelial cells with TGF beta could enhance the EBV infection rate by 3 to 5 folds while interferon treatment inhibits EBV infection. TGF beta is commonly present in the inflammatory stroma of human cancerous tissues including nasopharyngeal carcinoma and plays a significant role in modulating growth behavior and other biological properties of cancer and stromal cells. We hypothesized that TGF beta may play a significant role in mediating EBV infection into nasopharyngeal epithelial cells. Secretion of TGF beta by the inflammatory nasopharyngeal mucosa may facilitate the entry of EBV into nasopharyngeal epithelial cells. EBV infection into genetically altered clones of premalignant nasopharyngeal epithelial cells may drive their expansion and facilitate its malignant transformation. In this study, we propose to examine the mechanisms involved in the activation of EBV infection by TGF beta into nasopharyngeal epithelial cells. THE SMAD SIGNALING PATHWAY MAY BE INVOLVED IN EBV INFECTION INTO NASOPHARYNGEAL EPITHELIAL CELLS TGF-beta is an important cell signaling molecule. It is secreted by multiple cell types and is commonly present in the inflammatory stroma of human cancer including nasopharyngeal carcinoma. TGF beta has multiple actions on cells. It has growth inhibitory actions on many types of normal epithelial cells. Cancer cells commonly lost their responsiveness to the growth inhibition of TGF beta. We have also observed that nasopharyngeal epithelial cells have attenuated response to the growth inhibitory function of TGF beta. . The TGF-beta activates cell signaling through binding to the TGF-type II receptor (TGFBRII) which recruits and phosphorylates the TGF-type I receptor. The type I receptor then recruits and activates by phosphorylation the receptor regulated Smad (R-Smad), notably Smad 2 and Smad 3, which binds to the common Smad (CoSmad), Smad4 forming a heterodimeric complex which will be translocated to the cell nucleus to activate gene transcription. The potential involvement of Smad activation pathways in EBV infection has not been explored and will be the prime targets of this investigation. ENDOCYTOTIC PATHWAYS MAY BE INVOLVED IN THE EBV INFECTION OF NASOPHARYNEAL EPITHELIAL CELLS. Endocytosis is used by many viruses including EBV to enter cells. Various pathways are involved including clathin-dependent pathways, caveolae-dependent pathways and macropinocytosis which are independent of neither clathrin nor caveolae. There are reports showing that TGF-beta could influence endocytosis in cells. TGF-beta may influence these virus entry pathways to facilitate EBV infection into epithelial cells. SPECIFIC OBJECTIVES: 1. To examine if blocking of TGF-beta activation could effectively abolish EBV infection of nasopharyngeal epithelial cells. 2. To examine if downstream signaling pathways of TGF-beta are involved in EBV infection of nasopharyngeal epithelial cells 3. To examine if TGF beta may affect the common pathways involved in EBV entry.

Project Title:	AACR 101 st annual conference 2010 Epstein-Barr virus infection confer stress-resistant property in immortalized nasopharyngeal epithelial cells.
Investigator(s):	Tsao GSW
Department:	Anatomy
Source(s) of Funding:	URC/CRCG - Conference Grants for Teaching Staff
Start Date:	04/2010

Abstract:

N/A

List of Research Outputs

Chan M.C.W., Chan W.Y., Yu C.L., Ho C.C., Yuen K.M., Fong J.H.M., Tang L.L.S., Lai W.W.K., Lo A.C.Y., Chui W.H., Sihoe A.D.L., Kwong D.L.W., Tsao G.S.W., Poon L.L.M., Guan Y., Nicholls J.M. and Peiris J.S.M., Tropism and innate host responses of the 2009 pandemic H1N1 influenza virus in ex vivo and in vitro cultures of human conjunctiva and respiratory tract, American Journal of Pathology. 2010, 176(4): 1828-40.

Chan V.S.F., Tsao G.S.W. and Lin C.L.S., Toll prevents a move, Cancer Biology & Therapy. 2009, 8(19): 1838-1839.

Cheung A.K.L., Lung H.L., Ko J.M.Y., Cheng Y., Stanbridge E.J., Zabarovsky E.R., Nicholls J.M., Chua D.T.T., Tsao G.S.W., Guan X.Y. and Lung M.L., Chromosome 14 transfer and functional studies identify a candidate tumor suppressor gene, mirror image polydactyly 1, in nasopharyngeal carcinoma., In: George Klein, Proc Natl Acad Sci. 2009, 106: 14478-14483.

Cheung A.K.L., Lung H.L., Ko J.M.Y., Cheng Y., Stanbridge E.J., Zabarovsky E.R., Nicholls J.M., Chua D.T.T., Tsao G.S.W., Guan X.Y. and Lung M.L., Functional Studies of a Cell Cycle and Angiogenesis-related Candidate Tumor Suppressor Gene, Mirror Image Polydactyly 1 , in Nasopharyngeal Carcinoma, 16th Hong Kong International Cancer Congress. 2009.

Cheung P.P.Y., Deng W., Man C.W.Y., Tse W.W., Srivastava G., Law S.Y.K., Tsao G.S.W. and Cheung A., Genetic alterations in a telomerase-immortalized human esophageal epithelial cell line: Implications for carcinogenesis, Cancer Letters. 2010, 293: 41-51.

Fang E.F., Wong J.H., Bah C.S.F., Lin P., Tsao G.S.W. and Ng T.B., Bauhinia variegata var. variegata trypsin inhibitor: From isolation to potential medicinal applications, Biochemical and Biophysical Research Communications. 2010, 396: 806-811.

Feng E.F., Lin P., Wong J.H., Tsao G.S.W. and Ng T.B., A lectin with anti-HIV-1 reverse transcriptase, antitumor, and nitric oxide inducing activities from seeds of Phaseolus vulgaris cv. extralong autumn purple bean, Journal of Agricultural and Food Chemistry. 2010, 58: 2221-2229.

Friboulet L., Gourzones C., Tsao G.S.W., Morel Y., Paturel C., Temam S., Uzan C. and Busson P., Poly(I:C) induces intense expression of c-IAP2 and cooperates with an IAP inhibitor in induction of apoptosis in cancer cells, BMC Cancer. 2010, 10: 327.

Hong B., Lui V.W.Y., Hui E.P., Ng M.H.L., Cheng S.H., Sung F.L., Tsang C.M., Tsao G.S.W. and Chan A.T.C., Hypoxia-trageting by tirapazamine (TPZ) induces preferential growth inhibition of nasopharyngeal carcinoma cells with Chk1/2 activation, Invest New Drugs. 2009, 21.

Huen M.S.Y., Huang J., Leung J.W.C., Sy S.M.H., Leung K.M., Ching Y.P., Tsao G.S.W. and Chen J., Regulation of Chromatin Architecture by the PWWP Domain-Containing DNA Damage-Responsive Factor EXPAND1/MUM1, MOLECULAR CELL. 2010, 37(6): 854-864.

Hui K.F., Tsao G.S.W. and Chiang A.K.S., Suberoylanilide hydroxamic acid induces Epstein-Barr virus lytic cycle and enhanced apoptosis in nasopharyngeal carcinoma, 101st Annual Meeting of American Association for Cancer Research, Washington, DC, USA, 17-21 April. 2010.

Koo C.K., Wong K.L., Man C.W.Y., Tam H.L., Tsao G.S.W., Cheah K.W. and Lam M.H.W., Two-photon plasma membrane imaging in live cells by an amphiphilic, water-soluble cyctometalated platinum (II) complex. , Inorganic Chemistry. ACS publications, 2009, 48(16): 7501-7503.

Lam C.L.K., Chan G.C.F., Lam T.H., Lee P.P.W., Leung A.Y.M., Leung G.K.K. and Tsao G.S.W., 育醫造才: 探索醫學世界, 2010.

Law G.L., Wong K.L., Man C.W.Y., Tsao G.S.W. and Wong W.T., A two-photon europium complex as specific endoplasmic reticulum probe., Journal of Biophotonics . 2009, 2(12): 718-724.

Li B., Li Y.Y., Tsao G.S.W. and Cheung A., Targeting NF-kB signaling pathway suppresses tumor growth, angiogenesis, and metastasis of human esophageal cancer, Molecular Cancer Therapeutics. 2009, 8(9): 2635-2644.

Li J., Fung M.L., Xu A., Tsao G.S.W. and Leung W.K., Lipopolysaccharide causes hypoxia-inducible factor 1-alpha accumulation in gingival fibroblasts, 39^thAnnual Meeting of the American Association for Dental Research, Washington DC, 3/2010.

Liang Y., Zhong Z., Huang Y., Deng W., Cao J., Tsao G.S.W., Liu Q., Pei D., Kang T. and Zeng Y.X., Stem-like cancer cells are inducible by increasing genomic instability in cancer cells, The Journal of Biological Chemistry. 2010, 285(7): 4931-4940.

Lo P.H.Y., Lung H.L., Cheung A.K.L., Apte S.S., Chan K.W., Kwong F.M., Ko J.M.Y., Cheng Y., Law S.Y.K., Srivastava G., Zabarovsky E.R., Tsao G.S.W., Tang J.C.O., Stanbridge E.J. and Lung M.L., Extracellular Protease ADAMTS9 Suppresses Esophageal and Nasopharyngeal Carcinoma Tumor Formation by Inhibiting Angiogenesis, Cancer Research. 2010, 70(13): 5567-76.

Lui V.W.Y., Lau C.P.Y., Cheung C.S.F., Ho K., Ng M.H.L., Cheng S.H., Hong B., Tsao G.S.W., Tsang C.M., Lei K.I.K., Yamasaki Y., Mita A. and Chan A.T.C., An RNA-directed nucleoside anti-metabolite, 1-(3-C-ethynyl-beta-D-ribo-pentofuranosyl)cytosine (ECyd), elicits antitumor effect via TP53-induced glycolysis and apoptosis regulator (TIGAR) downregulation, Biochemical Pharmacology. 2010, 79: 1772-1780.

Lui V.W.Y., Yau D.M.S., Wong E.Y.L., Ng Y.K., Lau C.P.K., Ho Y., Chan J.P.L., Hong B., Ho K., Cheung C.S., Tsang C.M., Tsao G.S.W. and Chan A.T.C., Cucurbitacin I elicits anoikis sensitizaton, inhibits cellular invasion and in vivo tumor formation ability of nasopharyngeal carcinoma cells, Carcinogenesis. 2009, 30(12): 2085-2094.

Lung H.L., Cheung A.K.L., Cheng Y., Kwong F.M., Lo P.H.Y., Law W.L., Chua D.T.T., Zabarovsky E.R., Wang N., Tsao G.S.W., Stanbridge E.J. and Lung M.L., Functional characterization of THY1 as a tumor suppressor gene with anti-invasive activity in nasopharyngeal carcinoma, International Journal of Cancer. 2009, 127: 304-312.

Ma B.B.Y., Lui V.W.Y., Hui E.P., Lau C.P.Y., Ho K., Ng M.H.L., Cheng S.H., Tsao G.S.W. and Chan A.T.C., The activity of mTOR inhibitor RAD001 (everolimus) in nasopharyngeal carcinoma and cisplatin-resistant cell lines, Invest New Drugs. 2010, 28: 413-420.

Niu C., Tsao G.S.W. and Yip H.K.F., The anti-apoptotic role of telomerase in spinal cord motor neurons, 15th Research Postgraduate Symposium, The University of Hong Kong, Li Ka Shing Faculty of Medicine. 2009.

Or Y.Y.Y., Chung G.T.Y., To K.F., Chow C., Choy K.W., Tong C.Y.K., Leung A.W.C., Hui A.B.Y., Tsao G.S.W., Ng H.K., Yip T.T.C., Busson P. and Lo K.W., Identification of a novel 12p 13.3 amplicon in nasopharyngeal carcinoma, Journal of Pathology. 2010, 220: 97-107.

Poon C.T., Chan P.S., Man C.W.Y., Jiang F.L., Wong R.N.S., Mak N.K., Kwong D.W.J., Tsao G.S.W. and Wong W.K., An amphiphilic ruthenium (II)-polypyridyl appended porphyrin as potential bifunctional two-photon tumor-imaging and photodynamic therapeutic agent, Journal of Inorganic Biochemistry. 2010, 104: 62-70.

Sheu J.J.C., Lee C.H., Ko J.Y., Tsao G.S.W., Wu C.C., Fang C.Y., Tsai F.J., Hua C.H., Chen C.L. and Chen J.Y., Chromosome 3p12.3-p14.2 and 3q26.2-q26.32 are genomic markers for prognosis of advanced nasopharyngeal carcinoma, Cancer Epidemiol Biomarkers Prev. 2009, 18(10): 2709-2716.

Song L.B., Li J., Liao W.T., Feng Y., Yu C.P., Hu L.J., Kong Q.L., Xu L.H., Zhang X., Liu W.L., Li M.Z., Zhang L., Kang T.B., Fu L.W., Huang W.L., Xia Y.F., Tsao G.S.W., Li M., Band V., Band H., Shi Q.H., Zeng Y.X. and Zeng M.S., The polycomb group protein Bmi-1 represses the tumor suppressor PTEN and induces epithelial-mesenchymal transition in human nasopharyngeal epithelial cells, The Journal of Clinical Investigation. 2009, 119(12): 3626-3636.

Tang J., Feng Y., Tsao G.S.W., Wang N., Curtain R.P. and Wang Y., Berberine and Coptidis Rhizoma as novel antineoplastic agents: A review of traditional use and biomedical investigations. , Journal of Ethnopharmacology. . 2009, 126: 5-17.

Tsang C.M., Lau P.W.E., Di K., Cheung P.P.Y., Hau P.M., Ching Y.P., Wong Y.C., Cheung A., Wan T.S.K., Tong Y., Tsao G.S.W. and Feng Y., Berberine inhibits Rho GTPases and cell migration at low doses but induces G2 arrest and apoptosis at high doses in human cancer cells, International Journal of Molecular Medicine. 2009, 24: 131-138.

Tsang C.M., Zhang G., Seto E., Takada K., Deng W., Yip Y.L., Man C.W.Y., Hau P.M., Chen H., Cao Y., Lo K.W., Middeldorp J.M., Cheung A. and Tsao G.S.W., Epstein-Barr virus infection in immortalized nasopharyngeal epithelial cells: Regulation of infection and phenotypic characterization. , International Journal of Cancer. 2010, 127: 1570-1583.

Tsao G.S.W., Tsang C.M., Zhang G., Deng W., Hau P.M., Man C.W.Y., Kenzo T., Chen H., Yip Y.L., Lo K.W., Cao Y. and Cheung A., Epstein-Barr virus infection confer stress-resistant property in immortalized nasopharyngeal epithelial cells., Proceedings of American Association of Cancer Research. 2010.

Tsao G.S.W., Introduction to live cell imaging and confocal microscopy, HKU-Pasteur Research Center, Cell Biology Course. 2010.

Wong J.H.T., Lui V.W.Y., Umezawa K., Ho Y., Wong E.Y.L., Ng M.H.L., Cheng S.H., Tsang C.M., Tsao G.S.W. and Chan A.T.C., A small molecule inhibitor of NF-kB, dehydroxymethylepoxyquinomicin (DHMEQ), suppresses growth and invasion of nasopharyngeal carcinoma (NPC) cells, Cancer Letters. 2010, 287: 23-32.

Wong S.T.S., Chan W.S., Li C.H., Liu W.M., Tang W.W., Tsao G.S.W., Tsang R.K.Y., Ho W.K., Wei W.I. and Chan Y.W., Curcumin alters the migratory phenotype of nasopharyngeal carcinoma cells through up-regulation of E-cadherin , Anticancer Research. 2010, 30: 2851-6.

Wong S.T.S., Man O.Y., Tsang C.M., Tsao G.S.W., Tsang R.K.Y., Chan Y.W., Ho W.K., Wei W.I. and To V.S.H., Microrna Let-7 Suppresses Nasopharyngeal Carcinoma Cells Proliferation Through Downregulating C-myc Expression, Journal of Cancer Research and Clinical Oncology. Berlin, Springer Berlin / Heidelberg, 2010.

Yip Y.L., Tsang C.M., Jin Y., Deng W., Man C.W.Y., Cheung P.P.Y., Chen H., Cheung A. and Tsao G.S.W., The Epstein-Barr virus-encoded LMP1 extended the life span and immortalized nasopharyngeal epithelial cells., Hong Kong International Cancer Congress . 2009.

Researcher : Tse WW

List of Research Outputs

Cheung P.P.Y., Deng W., Man C.W.Y., Tse W.W., Srivastava G., Law S.Y.K., Tsao G.S.W. and Cheung A., Genetic alterations in a telomerase-immortalized human esophageal epithelial cell line: Implications for carcinogenesis, Cancer Letters. 2010, 293: 41-51.

Researcher : Van G

List of Research Outputs

Mi X., Chiu K., Van G., Leung J.W.C., Lo A.C.Y., Chung S.K., Chang R.C.C. and So K.F., The effect of lycium barbarum (wolfberry) on the expression of endothelin-1 and its receptors in an ocular hypertension model of glaucoma, 5th International Symposium on Healthy Aging. 2010, Page 55.

Researcher : Wang H

List of Research Outputs

Wang H., Lau W.M., Yau S.Y., Li S.Y., Leung N.E.L.S.O.N., Wang N.I.N.G.L.I., Tang S.W., Lee T.M.C. and So K.F., The roles of paroxetine and corticosterone on adult mammalian retinal ciliary body cell proliferation, The Chinese Medical Journal. 2010, 123: 1305-1310.

Researcher : Wang X

Project Title:	The role fo MAD2 in overcoming cisplatin resistance in testicular germ cell tumors
Investigator(s):	Wang X, Jin D
Department:	Anatomy
Source(s) of Funding:	Lance Armstrong Foundation - General Award
Start Date:	10/2003

Abstract:

To investigate the association between decreased MAD2 protein expression and cisplatin resistance in TGCT cells; to study if exogenous expression of the MAD2 gene in TGCT cells can lead to chemosensitization to cisplatin in TGCT cells; to demonstrate that downregulation of MAD2 results in resistance ot cisplatin in TGCT cells; to characterize the role of MAD2 in cisplatin-induced cell death inTGCT cells; to identify binding partners of MAD2 in response to cisplatin-induced DNA damage.

Project Title:	Significance of MAD2 expression to chromosomal instability in prostate cancer
Investigator(s):	Wang X, Jin D Y
Department:	Anatomy
Source(s) of Funding:	Association for International Cancer Research - General Award
Start Date:	04/2004

Abstract:

To correlate MAD2 expression with genomic instability in prostate cancer specimens; to show that MAD2 expression is essential for a functional mitotic checkpoint in prostate cancer cells; to demonstrate that downregulation of MAD2 leads to mitotic checkpoint defect and increased CIN in prostate cancer cells. • To investigate if promoter hypermethylation contributes to decreased MAD2 expression in prostate cancer

Project Title:	Molecular mechanisms involved in the suppressive effects of garlic derivatives on cell growth and motility in prostate cancer cells
Investigator(s):	Wang X, Jin D Y
Department:	Anatomy
Source(s) of Funding:	American Institute for Cancer Research (AICR) - General Award
Start Date:	08/2005

Abstract:

To study the role of the mitotic checkpoint in SAC and SAMC-induced androgen independent prostate cancer cell death; to investigate if SAC and SAMC have any inhibitory effect on the invasive ability of prostate cancer cells and to determine the molecular mechanisms responsible. Specific Aim 3. To examine if SAC and SAMC can enhance the sensitivity of prostate cancer cells to chemotherapeutic drugs.

List of Research Outputs

Blowers G.H. and Wang X., Military Psychology And Psychoanalysis: A Piece Of History With Surmise (In Chinese), Junshi xinlixue hejingshen fenxi: yiduan beicai cede lishi, In: Q.J. Shi and W. Senf , Psychotherapy in Dialogue: Psychoanalysis in China. Zhongguo Xinli Zhiliao Duihua, Hangzhou, Hangzhou Publishing House, 2009, 82-83.

Chua C.W., Chiu Y.T., Yuen H.F., Chan K.W., Man K., Wang X., Ling M.T. and Wong Y.C., Suppression of androgen-independent prostate cancer cell aggressiveness by FTY720: validating Runx2 as a potential antimetastatic drug screening platform, Clinical Cancer Research. 2009, 15(13): 4322-4335.

Yuen H.F., Chiu Y.T., Chan K.K., Chua C.W., McCrudden C.M., Tang K.H., El-Tanani M., Wong Y.C., Wang X. and Chan K.W., Prostate Cancer Cells Modulate Osteoblast Mineralisation And Osteoclast Differentiation Through Id-1 , British Journal of Cancer. 2010, 102: 332-341.

Researcher : Wang X

Project Title:	Angio-(1-7) and ACE2 during normal and hypertensive pregnancy
Investigator(s):	Wang X, Ellis-Behnke RG
Department:	Anatomy
Source(s) of Funding:	Small Project Funding
Start Date:	12/2008

Abstract:

Background of the Proposed Study: The Reni-Angiotensin System (RAS) plays a key role in cardiovascular system physiologically by implicating in mataining homeostatis of arterial pressure and hydroelectrolyte balance as well as in medulating cell growth and differentiation (Ferratio, 1990). Therefore, abnormal activation of the RAS has been associated with the pathophysiology of cardiovascular diseases including hypertension (Dostal and Baker, 1999; Zaman, 2002; Re, 2004). A review of the most recent literature in the related research has shown that ACE2, a newly discovered member of the RAS, a homolog of ACE (angiotensin converting enzyme), has gained attention among scientist because of cumulative evidence showing ACE2, by catalyzing the Ang-(1-7) generation, which antagonzes most of the cardiovascular actions of Ang II (angiotensin II) (Ferreia, 2005), potentially offer a cardiovascular protective effect. Recent studies on ACE2 expression and blood pressure regulation (Crackower, 2002), taken together the information on the Ang-(1-7) vasodilator and blood pressure lowering effects, suggest that ACE2 may play important role in blood pressure regulation by modeling the balance of vasoconstrictor and vasodilator components of RAS, which actually put ACE2-Ang-(1-7)-Mas axis as an important additional part to RAS (Raizada, 2008). However, in hypertension during pregnancy, it was remained an interesting question whether ACE2-Ang-(1-7) may paly a role in adjusting RAS to regulate blood pressure, and how? The first demonstration of the immunocytochemical distribution of Ang-(1-7) and ACE2 in kidneys of pregnant and virgin rat shows that pregnancy increases Ang-(1-7) and ACE2 intensity of staining by 56% and 117% respectively(Brosnihan, 2003). In human studies, both plasma levels of AngII and Ang-(1-7) were found increased in normal pregnant women as compared to non-pregnant subjects (Brosnihan, 2004). Since pregnancy is a physiological condition, where there has been found an activation of the RAS but blood pressure is normal or even decreased as being observed, thus, the enhanced expression of Ang-(1-7) may play critical role in the maintenance of blood pressure. It was firstly indicated that ACE2 may contribute to preserve normal blood pressure during pregnancy as shift in the AngII/Ang-(1-7) balance by contributing to increased Ang-(1-7) formation (Brosnihan, 2003). In pathological pregant subjects, i.e. preeclampsia, defined by de novo intragestational hypertension and proteinuria, levels of Ang II and Ang-(1-7) were found significantly reduced compared to the 3rd trimester of normal pregnancy; However, Ang II was found to be 50% higher than the Ang-(1-7) levels, suggesting that there is a shift of the balance of the peptides in preeclampsia, which might suggest it was due to this reduction of Ang-(1-7) that contribute to the higher blood pressure of during pathological pregnancy (Brosnihan, 2004). In a later report by the same group, the distribution of Angiotensin-(1-7) and ACE2 in human placentas of normal and pathological pregnancies in different cell types of the human placenta, has been evidenced firstly, including the syncytiotrophoblast, villous cytotrophoblast, invasive and intravascular trophblast, decidual cells, smooth vascular muscle of primary villi, and in arterial and venous umbilical endothelium (Valdes, 2005). It was found that, with the exception of an increased intensity of ACE2 in the arterial endothelium of the umbilical cord in preeclamptic pregnancies (0.5, 0.5-0.8 vs. 0.0, 0.0-0.0 in normal pregnancy, 95% CI, p=0.01), no differences were observed for the expression of Ang-(1-7) and ACE2 in the syncytiotrophoblast, fetal villous endothelium, umbilical cord endothelium and smooth muscle samples obtained from normal term or preeclamptic pregnancies. However, the author defenced that this lack of different expression of Ang-(1-7) and ACE2 between reproductive tissues obtained from normotensive and hypertensive gestation does not eliminate a potential causal role for Ang-(1-7)/ACE2 deficiency in gnesis or expresson of hypertensive pregancy (preeclampsia) (Valdes, 2006). In summary, it seems Ang-(1-7) as well as its generation enzyme ACE2 has been linked with the blood regulation during pregnancy both in animals and human beings, though the data has been fairly few, and, in another hand, the results have been reported inconsistantly. Therefore, more evidence need to be accumulated to uncover the role of ACE2/Ang-(1-7) locally and systemicly in regulating lood pressure during pregnancy, and thereafter to explore pathophysiologically the potential underline mechanism of patholoical gestation, such as preeclampsia or hypertensive gestation. Objectives of the Research Proposal: The main aim of the proposed study is to find out the distribution and expession difference in the levels, and intensities of cascades of local as well as circulation RAS in between non-, normal and pathological pregancies in animal. The objectives of the study entail: 1. To distribute a time change of circulating levels of ACE2, Ang-II, and Ang-(1-7) during a normal pregancy in Sprague-Dawley rat; 2. To compare the contents of Ang-(1-7), Ang-II and ACE2 in kidney in between virginal, normal pregnant and hypertensive pregnant Sprague-Dawley rat;

List of Research Outputs

Researcher : Wong R

List of Research Outputs

Yau S.Y., Lau W.M., Tong J., Wong R., Ching Y.P., Qiu G., Tang S.W., Lee T.M.C. and So K.F., Hippocampal cytogenesis and dendritic plasticity support running-enhanced memory and depression behavior, Proceedings of the International Anatomical Sciences and Cell Biology Conference, May 26-29, 2010. 37.

Yau S.Y., Lau W.M., Tong J., Wong R., Ching Y.P., Qiu G., Tang S.W., Lee T.M.C. and So K.F., Hippocampal cytogenesis and dendritic plasticity support running-enhanced memory and depression behaviour in stressed rat, The 4th Beijing International Forum on Rehabilitation, Oct. 28-30, 2009. 6-7.

Researcher : Wong YC

Project Title:	Induction of breast carcinogenesis by a combination of androgens and oestrogens
Investigator(s):	Wong YC, Xie B
Department:	Anatomy
Source(s) of Funding:	Other Funding Scheme
Start Date:	07/1997

Abstract:

To examine the role of both oestrogens and androgens in the initiation and progression of breast carcinogenesis in an animal model.

Project Title:	The Beijing, Hong Kong and UK Collaborative Study on the Molecular Genetic Basis of Differential Susceptibility of Prostate Cancer Between Chinese and Caucasian
Investigator(s):	Wong YC, Wang X, Ho KMT
Department:	Anatomy
Source(s) of Funding:	The University of Hong Kong Foundation Seed Grant
Start Date:	07/2003

Abstract:

To investigate molecular mechanisms responsible for racial differences in prostate cancer incidence.

List of Research Outputs

Chua C.W., Chiu Y.T., Yuen H.F., Chan K.W., Man K., Wang X., Ling M.T. and Wong Y.C., Suppression of androgen-independent prostate cancer cell aggressiveness by FTY720: validating Runx2 as a potential antimetastatic drug screening platform, Clinical Cancer Research. 2009, 15(13): 4322-4335.

Luk S.U., Yap W.N., Chiu Y.T., Lee D.T.W., Ma S.K.Y., Lee K.W., Vasireddy R.S., Wong Y.C., Ching Y.P., Nelson C.O.L.L.E.E.N., Yap Y.L. and Ling M.T., Gamma-tocotrienol as an effective agent in targeting prostate cancer stem cell-like population, International Journal of Cancer. 2010.

Tsang C.M., Lau P.W.E., Di K., Cheung P.P.Y., Hau P.M., Ching Y.P., Wong Y.C., Cheung A., Wan T.S.K., Tong Y., Tsao G.S.W. and Feng Y., Berberine inhibits Rho GTPases and cell migration at low doses but induces G2 arrest and apoptosis at high doses in human cancer cells, International Journal of Molecular Medicine. 2009, 24: 131-138.

Yuen H.F., Chiu Y.T., Chan K.K., Chua C.W., McCrudden C.M., Tang K.H., El-Tanani M., Wong Y.C., Wang X. and Chan K.W., Prostate Cancer Cells Modulate Osteoblast Mineralisation And Osteoclast Differentiation Through Id-1 , British Journal of Cancer. 2010, 102: 332-341.

Researcher : Wu EX

Project Title:	Magnetic resonance imaging for biomedical research
Investigator(s):	Wu EX
Department:	Engineering Faculty
Source(s) of Funding:	Seed Funding for New Staff
Start Date:	02/2004

Abstract:

To develop and acquire the basic and necessary software and hardware required for the MRI research at HKU.

Project Title:	Magnetic Resonance Measurement of Heart and Liver Iron
Investigator(s):	Wu EX
Department:	Electrical & Electronic Engg
Source(s) of Funding:	The National Institute of Diabetes and Digestive and Kidney Diseases
Start Date:	11/2006

Abstract:

1. Implementation and optimization of projection-reconstruction, gradient- and spin-echo imaging sequences to map T2 and T2* in test phantoms. The work initially will be performed at 7 Tesla for testing and then implemented for clinical imaging at 3 Tesla. This component of the research work will also include development of necessary software toolkits for image data analysis. 2.Optimization of clinical protocols at 3 Tesla for T2 and T2* measurements using projection-reconstruction, gradient- and spin-echo sequences in the anterior pituitary, pancreas and gonads. 3. Estimates of iron deposition in the anterior pituitary, pancreas and gonads using the optimized MRI protocols will be compared with the results of clinical evaluation of endocrine function in a group of thalassaemia patients with a wide range of body iron burdens.

Project Title:	Cell labeling for In Vivo MRI Monitoring after Transplantation in Cell Based Therapies
Investigator(s):	Wu EX
Department:	Engineering Faculty
Source(s) of Funding:	Small Project Funding
Start Date:	01/2007

Abstract:

In vivo monitoring of stem cells after grafting is essential for a better understanding of their migrational dynamics and differentiation processes and of their therapeutic potential. High-field magnetic resonance imaging (MRI) is potentially capable of tracking transplanted stem cells, and characterizing resulting anatomical, physiological and functional recovery in vivo, intact, and with high spatial resolution. We propose to develop such cellular imaging methodology on a 7 Tesla MRI scanner by (i) designing various techniques to label cells in vitro and quantitatively monitoring their in vivo distribution and activity after transplantation in stem cell therapy in rat stroke model; (ii) characterizing the therapeutic outcome in terms of anatomical structures and physiological functions using various MRI methods.

Project Title:	International Bioiron Society (IBIS) 2007 Meeting MRI CHARACTERIZATION OF FERRITIN-LIKE AND HEMOSIDERIN-LIKE IRON
Investigator(s):	Wu EX
Department:	Electrical & Electronic Engg
Source(s) of Funding:	URC/CRCG - Conference Grants for Teaching Staff
Start Date:	04/2007

Abstract:

N/A

Project Title:	Thalassaemia Major: A new MRI method for monitoring heart and liver iron deposition
Investigator(s):	Wu EX, Au WY, Ha SY
Department:	Electrical & Electronic Engg
Source(s) of Funding:	Children's Thalassaemia Foundation - General Awards
Start Date:	09/2007

Abstract:

To develop a new magnetic resonance imaging (MRI) method for detection and monitoring of heart iron deposition in patients with thalassaemia major and other forms of iron overload.

Project Title:	Thalassaemia major: a new MRI method for detection and monitoring of heart and liver iron deposition
Investigator(s):	Wu EX, Ha SY, Khong PL, Tse HF
Department:	Electrical & Electronic Engg
Source(s) of Funding:	General Research Fund (GRF)
Start Date:	09/2007

Abstract:

To develop and optimize new MRI pulse sequences to separately measure ferritin and hemosiderin iron by their distinctive effects on CPMG signal decay in phantoms containing water soluble nanometer-sized (ferritin-like) iron particles and water insoluble micron-sized (hemosiderin-like) iron particles and validate the MRI method by studies ex vivo of heart and liver samples from patients with iron overload in which ferritin and hemosiderin iron concentrations will be determined by biochemical measurement; to assess the new MRI determinations of tissue ferritin and hemosiderin iron in cross-sectional and prospective longitudinal studies of cardiac and hepatic function in thalassaemia patients with iron overload.

Project Title:	MR Study of High-order Water Molecule Diffusion in Biological Systems
Investigator(s):	Wu EX
Department:	Electrical & Electronic Engg
Source(s) of Funding:	Small Project Funding
Start Date:	12/2007

Abstract:

Diffusion tensor magnetic resonance imaging (DTI) has great potential to provide detailed information regarding central nervous system (CNS) tissue morphology and pathology. Often, the results of DTI studies are presented using summary parameters such as apparent diffusion coefficient (ADC) or fractional anisotropy (RA) that allow a simplified expression of water diffusion characteristics. While these summary parameters are convenient and are often highly correlated with disease progression, they fail to capture the specific, directional information inherent in the full DTI experiment. This project aims to develop, evaluate and validate a new in vivo and non-invasive MR diffusion kurtosis imaging (DKI) technique to charaterize CNS tissue. The specific objectives are: 1. Develop and implement MR data acquisition sequences. 2. Comprehensive analysis of the 2nd-order (conventional DTI approach) and 4th-order diffusion tensors. 3. Correlation of MRI DTI and DKI images with histology. 4. Monte Carlo simulation of diffusion kurtosis characteristics.

Project Title:	16th Scientific Meeting of International Society for Magnetic Resonance in Medicine (ISMRM) Relation of myocardial fiber structure with cardiac wall motion using DTI and MR tagging Myocardium structural remodeling with relation of infarct location and size in porcine model using DTI MR study of postnatal development of left ventricular myocardium structure and function in rats
Investigator(s):	Wu EX
Department:	Electrical & Electronic Engg
Source(s) of Funding:	URC/CRCG - Conference Grants for Teaching Staff
Start Date:	05/2008

Abstract:

N/A

Project Title:	30th Annual International Conference of the IEEE Engineering in Medicine and Biology Society Magnetic Resonance Imaging of Migrating Neuronal Precursors in Normal and Hypoxic-ischemic Neonatal Rat Brains by Intraventricular MPIO Labeling Preliminary In Vitro Study of Ultrasound Sonoporation Cell Labeling with Superparamagnetic Iron Oxide Particles for MRI Cell Tracking
Investigator(s):	Wu EX
Department:	Electrical & Electronic Engg
Source(s) of Funding:	URC/CRCG - Conference Grants for Teaching Staff
Start Date:	08/2008

Abstract:

N/A

Project Title:	Manganese-enhanced MRI for In Vivo Detection of Neurodegeneration in Neonatal Hypoxic-ischemic Brain Injury
Investigator(s):	Wu EX, Khong PL
Department:	Electrical & Electronic Engg
Source(s) of Funding:	General Research Fund (GRF)
Start Date:	09/2008

Abstract:

(1) Quantitative and longitudinal characterization of MEMRI, Mn-SOD and GS levels and Mn concentrations in two established neonatal rat H-I brain injury models (severe and mild H-I models): The purpose is to establish the spatiotemporal correlations between MEMRI measurements, enzyme levels and Mn levels; and (ii) assess the effect of Mn injection time and gradual clearance of Mn-SOD, GS and Mn in vivo; (2) Evaluation of MnDPDP for MEMRI in mild H-I model: The purpose is to experimentally evaluate MnDPDP, a clinically approved chelated Mn2+ contrast agent for liver MRI, for detection of Mn-SOD or/and GS activities in noncystic PVL model and assessment of any apparent toxicity.

Project Title:	Neuroimaging of Spontaneous Brain Activities in Anaesthetized Rodents
Investigator(s):	Wu EX
Department:	Electrical & Electronic Engg
Source(s) of Funding:	Small Project Funding
Start Date:	11/2008

Abstract:

In this study, electrophysiologicalrecordings and resting-state fMRI measurements will be conducted in anesthetized rats upon different isoflurane gas concentrations at various ages. The blood oxygenation level-dependent signal fluctuations will be correlated with the EEG power variations of delta, theta, alpha, beta, and gamma rhythms to investigate the relationship between hemodynamic and electrical oscillations.

Project Title:	Diffusion Kurtosis Imaging For Improved Neural Tissue Characterization By Magnetic Resonance
Investigator(s):	Wu EX, Khong PL, Wu W
Department:	Electrical & Electronic Engg
Source(s) of Funding:	General Research Fund (GRF)
Start Date:	09/2009

Abstract:

1) Implement and optimize our DKI method on a 7T rodent MRI scanner with a twice-refocused spin-echo sequence to minimize eddy current distortions, and to compute a complete set of DKI index maps using our directional kurtosis analysis protocol; 2) Evaluate our DKI method and analysis protocol by monitoring postnatal rodent brain development between postnatal day 0 and 360. Voxel-wise and ROI analysis will be performed to determine regional DKI index changes with time and to compare DKI with conventional DTI in detecting subtle microstructural alterations; 3) Evaluate our DKI method and analysis protocol by monitoring rodent brain aging longitudinally from postnatal year 1 to 2.5 with similar procedures and objectives.

Project Title:	31st Annual International Conference of the IEEE Engineering in Medicine and Biology Society Gas-filled Microbubbles – A Novel Susceptibility Contrast Agent for Brain and Liver MRI
Investigator(s):	Wu EX
Department:	Electrical & Electronic Engg
Source(s) of Funding:	URC/CRCG - Conference Grants for Teaching Staff
Start Date:	09/2009

Abstract:

N/A

Project Title:	In Vivo MRI of Endogenous Stem/Progenitor Cell Migration in Developing Brains
Investigator(s):	Wu EX
Department:	Electrical & Electronic Engg
Source(s) of Funding:	Small Project Funding
Start Date:	11/2009

Abstract:

The general objective of the present study is to employ the in situ cell labeling approach to characterize the migration of the endogenous NSPs from the SVZ in the postnatal developing rat brains in normal and HI-injured developing conditions. We further hypothesize that the NSP migrating patterns in normal and HI-injured developing brains will differ and can be detected by serial high-resolution in vivo MRI in addition to postmortem immunohistochemical analysis. Such in vivo MRI analysis can improve our understanding of NSP behavior in the developing mammalian brains and its alterations during injuries. The specific aims are: 1. MRI Determination of Migrating NSPs, Migration Patterns and Histological Colocalization in the Normal Developing Brains; 2. MRI Determination of Migrating NSPs, Migrating Patterns and Histological Colocalization in the HI-Injured Developing Brains; 3. Evaluation of Alteration of Migrating Pathways in HI-Injured Brains in Response to Injury.

List of Research Outputs

Liao S., Liu Y., Siu D.C.W., Zhang Y., Lai K.W.H., Au K.W., Lee Y.K., Chan Y.C., Yip P.M.C., Wu E.X., Lau C.P., Wu Y., Li R.A. and Tse H.F., Pro-arrhythmic Risk of Embryonic Stem Cell-Derived Cardiomyocytes Transplantation in Infarcted Myocardium. Heart Rhythm. , 2010.

Researcher : Wu G

List of Research Outputs

Liu M., Wu G. and Yip H.K.F., Expression of TERT and Telomerase aactivity in the rat central nervous system during aging, the University of Hong Kong Li Ka Shing Faculty of Medicine, Research Centre of Heart, Brain, Hormone & Healthy Aging, 5th International Symposium on Healthy Aging. 2010.

Researcher : Wu W

Project Title:	Effects of chondroitinase ABC and lithium chloride on neuronal survival and regeneration after spinal cord injury
Investigator(s):	Wu W, Yick LW, So KF
Department:	Anatomy
Source(s) of Funding:	Matching Fund for National Key Basic Research Development Scheme (973 Projects)
Start Date:	11/2003

Abstract:

To study the effects of chondroitinase ABC and lithium chloride on neuronal survival and regneration after spinal cord injury.

Project Title:	Axonal regeneration of CNS neurons after spinal cord injury
Investigator(s):	Wu W
Department:	Anatomy
Source(s) of Funding:	General Research Fund (GRF)
Start Date:	10/2006
Completion Date:	03/2010

Abstract:

The aim of this study is to examine the effects of combined treatments, lithium chloride (LiC1) plus chondroitinase ABC (ChABC), on neuronal regeneration after spinal cord injury (SCI) and to investigate the potential mechanisms of the treatments. Work programme: by using in vivo model the proposed study will investigate: (1) effects of combined treatment of ChABC and Lithium on axonal regeneration after SCI; (2) potential mechanisms of combined treatments on axonal regeneration after SCI.

Project Title:	Effects of lithium on the survival, proliferation and differentiation of neural stem cells transplanted into the rat spinal cord.
Investigator(s):	Wu W
Department:	Anatomy
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	09/2007
Completion Date:	08/2009

Abstract:

Objectives of the present study are: 1) to investigate whether lithium could induce neurogenesis and promote endogenous progenitor cells in injured spinal cord and, 2) to examine the effects of lithium on the survival, migration, proliferation and differentiation of grafted neural stem cells into the spinal cord. Rationale for the objectives: Why neural stem cells? Neural stem cell transplantation is a promising therapeutic strategy for the treatment of neurological diseases including brain and spinal cord injuries. The cell replacement of damaged neurons and oligodendrocytes and the production of neurochemically supportive molecules by engrafted cells could be the rational for using transplantation as a therapeutic approach (Bjorklund, 2000; Okano., 2002). Adult spinal cord shows very limited ability for spontaneous repair after injury. Although endogenous neural stem cells (NSCs) have been demonstrated to be present in the adult spinal cord (Horner et al., 2000), this cell type is clearly insufficient for significant repair of the injured spinal cord. Therefore, NSCs transplantation shows great potential for treating spinal cord injury. Many studies have shown that grafting NSCs into the lesion site of spinal cord after injury leads to improve structure growth and functional recovery. Delayed transplantation of neural progenitor cells into the contused spinal cord could induce neurogenesis and functional recovery (Ogawa et al., 2002), and promote remyelination (Karimi-abdolrezaee et al., 2006). Neural and glial restricted precursors transplantation into the injured spinal cord has been shown to improve bladder and motor functions and decrease thermal hypersentivity (Mitsui et al., 2005). However, the efficacy of NSCs transplantation in cell replacement and function restore is quite limited (Cao et al., 2002; Enzmann et al., 2005). Adult spinal cord is a hostile milieu for the grafted neural stem cells and the injured cord does not appear to support the long-term survival of transplanted stem cells (Chow et al., 2000). Transplantation of multipotent NSCs into the spinal cord leads to poor survival (Lepore et al., 2005), incomplete differentiation (Cao et al., 2001). Environmental factors, programmed cell death of grafted NSCs and host rejection would be the reasons contributing to the ultimate survival and differentiated phenotypes of grafted cells. Therefore, how to enhance survival, proliferation and differentiation of transplanted NSCs in the host spinal cord is essential for the application of NSCs transplantation therapy. Immune suppression, inflammation control, apoptosis inhibition and lesion environment modification as well as mobilization of endogenous stem cells are believed to benefit the application of cell transplantation therapy. Why lithium? Recently, increasing documents have shown that small molecules are capable of inducing neurogenesis and promoting proliferation, survival, migration or maturation of neural precursor cells (Longo et al., 2006). Lithium, a widely used antidepressant drug, is reported to markedly increase the proliferation and neuronal differentiation of cultured hippocampal neural progenitor cells (Kim et al., 2004). It can also stimulate progenitor proliferation in cultured brain neurons (Hashimoto et al., 2003) and inhibit apoptosis of mouse neural progenitor cells (Shimomura et al., 2003). In vivo lithium has been demonstrated to enhance hippocampal neurogenesis (Chen et al., 2000) as well as proliferation of dentate gyrus progenitor cells (Son et al., 2003). On the other hand, little literature was reported whether lithium could induce neurogenesis, modify glial reaction, alleviate the inflammation and promote activation of endogenous progenitor cells in injured spinal cord. It is also not clear whether lithium could exert promotive effects on the survival, migration, proliferation and differentiation of grafted neural stem cells into the spinal cord. Therefore, objectives of the present study focuses on the effects of lithium on endogenous progenitor cells and transplanted NSCs in injured spinal cord and. Preliminary results Since this is a new research project for the PI, in order to achieve the objectives of the study we have performed a few preliminary experiments, which include 1) establishing methods for isolating and culturing fetal NSCs from GFP rats; and 2) establishing method for transplantation of cultured NSCs into the rat spinal cord. Results of these preliminary studies demonstrated that NSCs from GFP fetal rat can be isolated, cultured, identified and transplanted into wild type rat spinal cord in our lab (Fig 1, attachment 1). With these successful preliminary results we are sure we can achieve the objectives of the proposed project. Reference: Bjorklund A . Novartis Found Symp. (2000), 231:7-15. Cao et al., Exp. Neurol. (2001) 167:48-58. Cao et al., J Neurosci. Res. (2002) 68:501-510. Chen et al., J Neurochem. (2000) 75(4):1729-34. Chow et al., Brain Res. (2000), 874:87-106. Enzmann et al., Exp. Neurol. (2005), 195:293-304. Hashimoto et al., Neuroscience. (2003), 117(1):55-61. Horner et al., J Neurosci. (2000) 20(6):2218-28. Karimi-abdolrezaee et al., J Neurosci. (2006), 26(13):3377-89. Kim et al., J Neurochem. (2004) 89(2):324-36. Lepore et al., Exp. Neurol. (2005), 194:230-242. Longo et al., Curr Alzheimer Res. (2006), 3(1):5-10. Mitsui et al., J Neurosci. (2005) 25(42):9624-36. Ogawa et al., J Neurosci. Res. (2002), 69:925-933. Okano., Keio J Med. (2002) 51(3):115-28. Shimomura et al., Neuroreport. (2003) 14(14):1779-82. Son et al., 2003 J Neurochem. (2003) 85(4):872-81.

Project Title:	Remyelination and axonal integrity in MOG-induced experimental autoimmune encephalomyelitis by transplantation of oligodendrocyte precursor cells
Investigator(s):	Wu W
Department:	Anatomy
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	04/2008

Abstract:

Objective Objective of the present study is to investigate whether transplantation of oligodendrocyte precursor cell (OPC) together with treatment of lithium could promote spinal cord remyelination and axonal integrity in MOG-induced experimental autoimmune encephalomyelitis (EAE). Rationale for the use of OPCs Demyelinating diseases are characterized by the loss of myelin sheath of axons due to extensive inflammation and gliosis in the central nervous system (CNS). A typical example of demyelinating diseases is multiple sclerosis (MS). The main pathological characteristics of MS are widespread demyelination and oligodendrocyte degeneration (Merrill et al., 1999). Degeneration of oligodendrocytes not only results in demyelination but also cause degeneration of axons and neurons in the late stage of MS (Rieckmann et al., 2001). Demyelination, axonal loss and neuronal degeneration in MS contribute directly to the disability motor and sensory functions (De Stefano N et al., 1998). The experimental autoimmune encephalomyelitis (EAE) model is the widely accepted animal model of multiple sclerosis (MS) (Wekerle et al., 1994; Kerschensteiner et al., 2004). Myelin sheaths and oligodendrocytes are the primary targets in EAE induced demyelination. The key issue in MS is the demyelination and degeneration of oligodendrocytes. Therefore, preventing demyelination and degeneration of oligodendrocytes is critical to slow or stop the progress of MS and could become a potential therapeutically procedure. Clinically established strategies for the treatment of MS mostly target the autoimmune response by using anti-inflammatory, immunomodulatory and immunosuppressive agents (Noseworthy et al., 1999). These agents have been proved to be beneficial for modifying the clinical disease course. However, none of them have demonstrated clear neuroprotective properties. One strategy to restore re-myelination in MS is to prevent the degeneration of oligodendrocyte. Recent studies demonstrated that LINGO-1 (LRR and Ig domain-containing, Nogo Receptor-interacting protein) is an important negative regulator of myelination. LINGO-1 is expressed in oligodendrocytes. Overexpression of LINGO-1 leads to inhibition of oligodendrocyte differentiation and myelination (Mi et al., 2004, 2005). Most recently we reported that application of antibody against LINGO-1 promotes spinal cord remyelination and axonal integrity in MOG-induced EAE animals (Mi et al., 2007). Another strategy to enhance re-myelination is to promote endogenous OPCs in the lesion regeion and its borders. It is suggested that this rapid response of OPCs to repopulate the lesion site and their subsequent differentiation into new oligodendrocytes is likely to contribute to the remyelination (Reynolds et al., 2002; Ben-Hur et al., 2003). However, the numbers of endogenous OPCs are not enough for remyelination of injured axons in the spinal cord (Jason et al., 2005). In the proposal study we will investigate whether transplantation of cultured OPCs could produce remyelination in the EAE model. We will also test whether treatment with lithium could enhance OPCs survival and differentiation after been transplanted into the lesioned spinal cord. Rationale for the use of lithium Adult spinal cord is a hostile milieu for the grafted cells and the injured cord does not appear to support the long-term survival of transplanted neural stem cells (NSCs) (Chow et al., 2000). Transplantation of multipotent NSCs into the spinal cord leads to poor survival (Lepore et al., 2005), incomplete differentiation (Cao et al., 2001). Environmental factors, programmed cell death of grafted NSCs and host rejection would be the reasons contributing to the ultimate survival and differentiated phenotypes of grafted cells. Therefore, how to enhance survival, proliferation and differentiation of transplanted OPCs in the host spinal cord is essential for the application of OPCs transplantation therapy. Our recent study has shown that lithium can inhibit the immunoreaction of the host and enhance the survival and differentiation rates of transplanted NSCs into the spinal cord (Su et al., 2007). Increasing documents have also shown that lithium markedly increased the proliferation and neuronal differentiation of cultured hippocampal neural progenitor cells (Kim et al., 2004). It can also stimulate progenitor proliferation in cultured brain neurons (Hashimoto et al., 2003) and inhibit apoptosis of mouse neural progenitor cells (Shimomura et al., 2003). In vivo lithium has been demonstrated to enhance hippocampal neurogenesis (Chen et al., 2000) as well as proliferation of dentate gyrus progenitor cells (Son et al., 2003). On the other hand, little literature was reported whether lithium could exert promotive effects on the survival, migration, proliferation and differentiation of grafted OPCs into the spinal cord in the MS model. Therefore, objectives of the present study focuses on the effects of lithium on the survival and differentiation of transplanted OPCs in injured spinal cord of MS model. References: Merrill JE et al., Neuropathol Appl Neurobiol., 25:435-58, 1999. Rieckmann P et al., Trends Neurosci., 24:435-7, 2001. De Stefano N et al., Brain, 121:1469-77, 1998. Wekerle M et al., Ann Neurol Suppl., 36:S47-53, 1994. Kerschensteiner M et al., Am J Pathol., 164(4):1455-69, 2004. Noseworthy JH et al., Curr Opin Neurol., 12: 279-93, 1999. Mi S et al., Nature Neurosci., 7:221-28, 2004. Mi S et al., Nature Neurosci., 8:745-51, 2005. Mi S et al., Nature Medicine, 13:1228-1233, 2007. Reynolds R et al., J Neurocytol., 31(6-7):523-36, 2002. Ben-Hur T et al., Glia, 41(1):73-80, 2003. Jason F et al., Exp Neurol., 192: 11-24, 2005. Chow et al., Brain Res. 874:87-106, 2000. Lepore et al., Exp. Neurol. 194:230-242, 2005. Cao et al., Exp. Neurol. 167:48-58, 2001. Su H et al., Exp. Neurol. 206:296-307, 2007 Kim et al., J Neurochem. 89(2):324-36, 2004. Hashimoto et al., Neuroscience. 117(1):55-61, 2003. Shimomura et al., Neuroreport. 14(14):1779-82, 2003. Chen et al., J Neurochem. 75(4):1729-34, 2000. Son et al., 2003 J Neurochem. 85(4):872-81, 2003.

Project Title:	Research Output Prize
Investigator(s):	Wu W, Su H, Wong WM, So KF, Wu EX
Department:	Anatomy
Source(s) of Funding:	Research Output Prize (in Faculty)
Start Date:	10/2008

Abstract:

To identify and recognize the best research outputs in different faculties.

Project Title:	Implantation of trophic factor-treated sensory nerve graft for motoneuron regeneration after spinal root avulsion injuries
Investigator(s):	Wu W
Department:	Anatomy
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	06/2009

Abstract:

Objective: The overall objective of the proposal is to investigate strategies to promote motoneuron axon regeneration into implanted nerve graft after avulsion. The long-term goal of the study is to improve functional recovery using nerve graft after spinal root avulsion injuries. Rationale: Spinal root avulsion is the most severe type of brachial plexus injuries which are mostly caused by motor/vehicle accidents or complicated birth. Unfortunately, seventy percent of brachial plexus injuries involve avulsion of one or more root(s). These patients suffer from paralysis in the corresponding muscle groups and loss of sensory function. In addition, motoneurons die gradually if left unattended. One of the possible approaches to rescue the motoneurons is to implant peripheral nerve graft or re-implant the avulsed roots. Implantation of nerve graft serves two purposes, one is to provide neurotrophic factors released from Schwann cells for survival of motoneurons; another is to provide a conduit to bridge the spinal cord with the distal nerve for axon regeneration and functional recovery. Despite recent advances in microsurgical technique, functional recovery is achievable yet not satisfactory. There are several important issues need to be addressed. First of all, avulsed root retracts if surgical intervention is delayed, this renders the avulsed root infeasible for re-implantation. Nerve grafts have to be harvested which leads to the second problem. Autologous sensory nerve graft is an alternative to avulsed root. However recent findings in experimental and clinical reports showed that sensory nerve is inferior to motor nerve in promoting axon regeneration, additional treatments have to be sought to improve the neuro-regenerative ability of sensory nerve. It is well known that certain neurotrophic factors promote survival and regeneration of motoneurons, thus neurotrophic factors are likely candidates for treatments in avulsion injuries. Thirdly, axon regeneration after avulsion is different from that in peripheral nerve injuries. Motor axons need to regenerate for a certain distance within the central nervous system (CNS) before entering into the nerve graft. Another possible route is to grow on surface of the cord before entering the graft. How axons navigate in such hostile environment remains unclear. Lastly, use of artificial conduit in peripheral nerve surgeries is common. It eliminates the need to harvest a segment of healthy nerve. Yet no synthetic graft is available up to date for avulsion injuries. We consider acellular allogeneic nerve graft as an alternative option for autologous nerve. Specific objectives: 1. To investigate the effects of neurotrophic factor on promoting survival and regeneration of avulsed motoneurons; 2. To investigate how neurotrophic factors modulate regeneration of motoneurons; Expect outcome Our preliminary results showed that motor nerve is better than sensory nerve in promoting survival and regeneration of motoneurons after avulsion. The different outcome is due to a higher level of neurotrophic factors such as brain-derived neurotrophic factor (BDNF) and glial cell line-derived neurotrophic factor (GDNF) in motor nerve. These results highlight the importance of neurotrophic factors present in the nerve graft. It is supported by a trial study which we showed single injection of GDNF into nerve graft substantially increases regeneration of motoneurons. We expect that continuous delivery of neurotrophic factors can further enhance the regenerative ability of motoneurons and promote functional recovery, especially in long term study. If additional fund are available in the future, it is also tempting to test other trophic factors, alone or in combination, in mediating motoneuron survival and regeneration. We expect that combination of trophic factors can exert synergistic effects. Recent findings by others showed that neurotrophic factors also exert chemo-attraction for Schwann cells which are present in avulsed stump. We expect that infusion of trophic factors into acellular nerve graft can induce migration of Schwann cells into the graft which then subsequently promote axon regeneration.

Project Title:	Effects and mechanisms of fingolimod on oligodendrocyte maturation and remyelination in animals with experimental autoimmune encephalomyelitis
Investigator(s):	Wu W
Department:	Anatomy
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	01/2010

Abstract:

General purpose of the project: The overall purpose of this proposal is to investigate the effects of fingolimod (FTY720), an analog of sphingosine-1-phosphate (S1P), on the survival, maturation and myelination of OPCs in a multiple sclerosis (MS) model, the experimental autoimmune encephalomyelitis (EAE) animal model, and to study the role of S1P5 receptor in mediating cell fates of OPCs both in vitro and in vivo. Data obtained from the current study will form a base for seeking external research grant, such as RGC grant. Key issues: The key issue in MS is the demyelination of axons and degeneration of oligodendrocytes due to autoimmune response in the CNS. Strategies for the treatment of MS were mainly focused on two aspects: 1) to regulate the autoimmune response in order to reduce the attack of oligodendrocytes. Majority of the studies were focused on this aspect. Clinically established strategies for the treatment of MS are also targeting the autoimmune response by using anti-inflammatory, immunomodulatory and immunosuppressive agents. Although these agents have been proven to be beneficial for modifying the disease course, none of them have demonstrated clear neuroprotective properties; 2) to promote remyelination by stem cells. Our lab focuses on enhancing remyelination by OPCs which can differentiate into mature oligodendrocytes and remyelinate axons. We demonstrated that suppressing LINGO-1, an important negative regulator of myelination, significantly enhances oligodendrocyte maturation, speeds up remyelination and improves motor function in EAE animal models. MS has multifactorial causes. It requires multiple targets for efficient treatment. FTY720 is one of the drugs emerged recently in a clinical study for the treatment of MS. It demonstrated promising effects in reducing the relapse rate in the recruited patients. Its primary action is to keep lymphocytes in lymph nodes and thus reduce the number of lymphocyte circulating in the CNS. FTY720 binds to S1P receptor (S1PR) on lymphocyte cell surface, leading to abberant internalization of the receptor. Absence of the receptor prevents the cells migrate out of their lymph nodes. Importantly, S1PRs are also present on cells of oligodendrocyte lineage. Four isoforms of S1PR were identified in oligodendrocyte precursor cells (OPCs) including S1P1-3 and S1P5 receptors. It was recently found in cell culture that FTY720 enhances the survival of OPCs via S1P1 receptor and inhibits differentiation and migration via S1P5 receptor. However the exact roles of these receptors in mediating OPC fates are yet to be determined in vivo, especially in MS models. It is unknown whether FTY720 has effect on the maturation of OPCs in MS patient or animal models in addition to its effect on lymphocytes. In the proposed study, we aim at studying the effect of FTY720 on survival and maturation of OPCs under the pathological conditions in an EAE animal model. To further speed up the remyelination process, we will transplant exogenous OPCs into the EAE-induced animals and co-treated with FTY720 to promote their survival. To overcome the negative regulative effect of S1P5 receptor on the maturation of OPCs, we will silence or block S1P5 receptor so that the transplanted OPCs could migrate and form mature oligodendrocytes (OLGs) in vivo. We hypothesize that the beneficial effects of FTY720 are not only mediated through immuno-suppressive action but also direct protective effects on oligodendroglial lineage cells. Specific objectives: 1. To investigate the effects of FTY720 on the survival of endogenous and exogenous OPCs, remyelination of axons and functional recovery in EAE animals; 2. To investigate the effects of blocking S1P5 receptor on the survival, proliferation, differentiation, migration and remyelination of OPCs.

List of Research Outputs

Cai J., Li W., Su H., Qin D., Yang J., Zhu F., Xu J., He W., Guo X., Labuda K., Peterbauer A., Wolbank S., Zhong M., Li Z., Wu W., So K.F., Redl H., Zeng L., Esteban M.A. and Pei D., Generation of human induced pluripotent stem cells from umbilical cord matrix and amniotic membrane mesenchymal cells, The Journal of Biological Chemistry. 2010, 285(15): 11227-11234.

Chu T.H. and Wu W., Use Of Gdnf In Acellular Nerve Graft For Axonal Regeneration After Spinal Root Avulsion, Society for Neuroscience 2009.

Ellis-Behnke R.G., Liang Y., Guo J., Tay D.K.C., Schneider G.E., Teather L.A., Wu W. and So K.F., Forever young: how to control the elongation, differentiation and proliferation of cells using nanotechnology, Cell Transplantation. 2009.

Ellis-Behnke R.G., Liang Y., Cheung W.H., So K.F., Wu W. and Tay D.K.C., Redefining tissue engineering for nanomedicine: Visualizing the progress of regenerating axons in the mammalian visual system after complete transection and treatment with self-assembling nanomaterial, 6th Annual World Congress for Brain Mapping and Image Guided Therapy, Harvard Medical School, Boston MA. 2009.

Fu Q., Li X., Yip H.K.F., Shao Z.H., Wu W., Mi X. and So K.F., Combined effect of brain-derived neurotrophic factor and LINGO-1 fusion protein on long-term survival of retinal ganglion cells in chronic glaucoma, Neuroscience Bulletin. 2009, 25(1): 171-172.

Wu W., Cell transplantation for spinal cord injury and neuronal degenerative diseases, The 3rd China International Congress of Orthopaedics (CICO), Beijing, China, August 7-9, 2009. 2009.

Xiao Q., Du Y., Wu W. and Yip H.K.F., Bone Morphogenetic Proteins Mediate Cellular Response And, Together With Noggin, Regulate Astrocyte Differentiation After Spinal Cord Injury, Experimental Neurology. Elsevier, 2010, 221: 353-366.

Yuan Q., Hu B., Wu Y., Chu T.H., Su H., Zhang W., So K.F., Lin Z. and Wu W., Induction of c-Jun phosphorylation in spinal motoneurons in neonatal and adult rats following axonal injury, Brain Research. 2010, 1320: 7-15.

Researcher : Xiao Q

List of Research Outputs

Xiao Q., Du Y., Wu W. and Yip H.K.F., Bone Morphogenetic Proteins Mediate Cellular Response And, Together With Noggin, Regulate Astrocyte Differentiation After Spinal Cord Injury, Experimental Neurology. Elsevier, 2010, 221: 353-366.

Xiao Q. and Yip H.K.F., Differentiation plasticity of neural stem cells in the injured adult mouse spinal cord is regulated by bone morphogenetic proteins (BMPs), USA Society of Neuroscience Annual Meeting. 2009.

Researcher : Xu H

List of Research Outputs

Poon H.F., Xu H. and Ching Y.P., Characterization of the Roles of PAK5 in Neuronal Development , In: Prague, Czech Republic, 34th FEBS Congress: Life's Molecular Interactions. 2009.

Researcher : Yang D

List of Research Outputs

Yang D., Yeung C.M., Li S.Y., Chang R.C.C., So K.F., Wong D.S.H. and Lo A.C.Y., Lycium Barbarum Polysaccharides Protects Brain From Ischemia/reperfusion Injury, Joint Annual Scientific Meeting of the Hong Kong Society of Neurosciences and the Biophysical Society of Hong Kong. 2010.

Researcher : Yang J

Project Title:	Investigation of physiology and possible neuroprotective effect of the retinal microglia under normal and glaucoma conditions
Investigator(s):	Yang J, So KF, Chang RCC
Department:	Anatomy
Source(s) of Funding:	Small Project Funding
Start Date:	11/2008

Abstract:

Microglial cells are the major immunocompetent cells in the brain, abundantly presented in all regions of CNS tissue including optic nerve and retina. It was shown that at the resting state, microglia were characterized by a ramified morphology, and there was no function attributed to it; While upon any kind of pathology occurred in brain environment, microglia could rapidly transform into activated state, characterized by an ameboid morphology, and migrate to the site of injury, proliferating and releasing a variety of factors such as cytokines or nitric oxide. However, recent studies show that microglia carry out active tissue scanning, which challenges the traditional notion of ‘resting’ microglia in the normal brain. More over, it has been suggested that attenuation of microglial activation has neuroprotective effect and restricts damage during acute excitotoxicity. Our laboratory has long been interested in neuroprotection and regeneration in CNS. Specifically, research in our group has concentrated on retinal ganglion cell (RGC) protection under glaucoma. Recent study of our group shows that microglia can be stimulated into different reactive states and display distinctive morphology under a dose-dependent manner. While high concentration (1000ng) monocyte chemoattractant protein 1 (MCP-1) and lipopolysaccharide (LPS) promoted microglia activation and exacerbated retinal ganglion cell loss in experimental glaucoma, 100 ng MCP-1 provided neuroprotection towards RGC, concomitant with a unique morphology of microglia, termed semi-activated microglia. Since few studies has been done to investigate the property of retinal microglia and it is unclear what role it may play in normal and pathological conditions, it is crucial to understand physiological characteristics of the retinal microglia under different reactive states (i.e. resting state, semi-activated state and activated state). This research project will be focused on the physiological characteristics of the retinal microglia, especially under glaucoma condition, using whole-cell patch clamp and single channel recording techniques. First aim is to determine the physiology and iron channel properties of the retinal microglia in normal condition. Secondly, I will try to find out if there are any distinctive electrophysiology characteristics of the microglia under different reactive states in glaucoma condition. Further more, I will try to investigate the possible neuroprotective effect of the retinal microglia and its relationships with its physiology characters. Finally, the electrophysiology results will be combined with existing cell biology and imaging data from our laboratory and hopefully to provide a more comprehensive view of the character and the function of the retinal microglia. And these results could also be benefit for the understanding of other type of neurodegenerative diseases occurred in different brain areas.

Researcher : Yang X

List of Research Outputs

Chang R.C.C., Yang X., Ho Y.S., Yeung S.C. and Mak J.C.W., Alzheimer-like pathology in rat receiving passive smoking, Society for Neuroscience 2009. Program No. 626.13: Poster No. H26.

Ho Y.S., Yu M.S., Yang X., So K.F., Yuen W.H. and Chang R.C.C., Neuroprotective effects of polysaccharides from wolfberry, the fruits of Lycium barbarum. against homocysteine-induced toxicity in rat cortical neurons, Journal of Alzheimer's Disease. 2010, 19: 813-827.

Ho Y.S., Yang X., Yu M.S., So K.F. and Chang R.C.C., Polysaccharides from Wolfberry (Lycium barbarum) antagonize homocysteine-induced neurotoxicity in cultured cortical neurons, Society for Neuroscience 2009. Program No. 626.3: Poster No. H16.

Ho Y.S., Yang X., Wang J., So K.F. and Chang R.C.C., The relationship between ER stress and TAU phosphorylation - Do they affect each other?, 5th International Symposium on Healthy Aging,. 2010, Page 63.

Yang X., Effect of nitric oxide on the proliferation and differentiation of neural precursor cells derived from embryonic rat spinal cord... 2010, 94 pages.

Researcher : Yang X

List of Research Outputs

Chang R.C.C., Yang X., Ho Y.S., Yeung S.C. and Mak J.C.W., Alzheimer-like pathology in rat receiving passive smoking, Society for Neuroscience 2009. Program No. 626.13: Poster No. H26.

Yang X., Effect of nitric oxide on the proliferation and differentiation of neural precursor cells derived from embryonic rat spinal cord... 2010, 94 pages.

Researcher : Yau SY

List of Research Outputs

Lau W.M., Yau S.Y., Lee T.M.C., Ching Y.P., Tang S.W. and So K.F., Corticosterone suppresses dendritic maturation of immature neurons in hippocampus, which is counteracted by antidepressant treatment, Neuroscience Bulletin. 2009, 25(1): 450.

Lau W.M., Yau S.Y., Lee C.D., Chang R.C.C. and So K.F., Effect of Lycium Barbarum (Wolfberry) polysaccharide on sexual behavior of male rats, Collegium Internationale Neuro-Psychopharmacologicum (CINP) 2010 World Congress. 2010, P-02.

Lau W.M., Yau S.Y., Lee T.M.C., Ching Y.P., Tang S.W. and So K.F., Effect of corticosterone and paroxetine on masculline mating behavior: Possible involvement of neurogenesis, Pan Pacific Symposium on Stem Cells Research, April 16-19, 2010, Taiwan. 2010, 77.

Lau W.M., Yau S.Y., Lee C.D., Chang R.C.C. and So K.F., Lycium barbarum (wolfberry) polysaccharide facilitates ejaculatory behaviour in male rats. , Annual Meeting of the Australian Neuroscience Society. 2010.

Lau W.M., Yau S.Y., Lee T.M.C., Ching Y.P., Tang S.W. and So K.F., Possible involvement of neurogenesis in male rat mating behavior, Cell Transplantation. 2010, 19(3): 347.

Wang H., Lau W.M., Yau S.Y., Li S.Y., Leung N.E.L.S.O.N., Wang N.I.N.G.L.I., Tang S.W., Lee T.M.C. and So K.F., The roles of paroxetine and corticosterone on adult mammalian retinal ciliary body cell proliferation, The Chinese Medical Journal. 2010, 123: 1305-1310.

Wang H., Lau W.M., Yau S.Y., Li S.Y., Leung N., Tang S.W., Lee T.M.C. and So K.F., Roles of paroxetine and corticosterone on adult mammalian ciliary body cell proliferation. , Chinese Medical Journal. 2010, 123: 1305-1310.

Wang H., Lau W.M., Yau S.Y., Li S.Y., Leung N., Wang N.L., Tang S.W., Lee T.M.C. and So K.F., Roles of paroxetine and corticosterone on adult mammalian ciliary body cell proliferation, Chinese Medical Journal. 2010, 123: 1305-1310.

Yau S.Y., Lau W.M., Tong J., Ching Y.P., Lee T.M.C. and So K.F., Hippocampal cell proliferation and dendritic enrichment is essential for beneficial effects of exercise on stressed animal model, Hellenic Society for Neuroscience, 23rd Annual Meeting, September 13-14, 2009, Greece.. 2009, 78-79.

Yau S.Y., Lau W.M., Tong J., Wong R., Ching Y.P., Qiu G., Tang S.W., Lee T.M.C. and So K.F., Hippocampal cytogenesis and dendritic plasticity support running-enhanced memory and depression behavior, Proceedings of the International Anatomical Sciences and Cell Biology Conference, May 26-29, 2010. 37.

Yau S.Y., Lau W.M., Tong J., Wong R., Ching Y.P., Qiu G., Tang S.W., Lee T.M.C. and So K.F., Hippocampal cytogenesis and dendritic plasticity support running-enhanced memory and depression behaviour in stressed rat, The 4th Beijing International Forum on Rehabilitation, Oct. 28-30, 2009. 6-7.

Yau S.Y., Lau W.M., Tong J.B., Ching Y.P., Qiu G., Lee T.M.C. and So K.F., Hippocampal neurogenesis and dentritic enrichment are involved in neuroprotective of physical exercise on stress., Neuroscience Bulletin. . 2009, 25 Supp 1: 379-380.

Yau S.Y., Neuroprotective effects of physical exercise on stressed brain: Its relationship to hippocampal neurogenesis and dendritic remodeling. 2009, 199 pages.

Zhang E., Yau S.Y., Lau W.M., So K.F. and Chang R.C.C., Anti-depressive effects of Lycium Barbarum in a rat depression model, Collegium Internationale Neuro-Psychopharmacologicum (CINP) 2010 World Congress. 2010, P-09.

Researcher : Yau SY

List of Research Outputs

Lau W.M., Yau S.Y., Lee T.M.C., Ching Y.P., Tang S.W. and So K.F., Possible involvement of neurogenesis in male rat mating behavior, Cell Transplantation. 2010, 19(3): 347.

Yau S.Y., Lau W.M., Tong J., Wong R., Ching Y.P., Qiu G., Tang S.W., Lee T.M.C. and So K.F., Hippocampal cytogenesis and dendritic plasticity support running-enhanced memory and depression behaviour in stressed rat, The 4th Beijing International Forum on Rehabilitation, Oct. 28-30, 2009. 6-7.

Yau S.Y., Neuroprotective effects of physical exercise on stressed brain: Its relationship to hippocampal neurogenesis and dendritic remodeling. 2009, 199 pages.

Researcher : Yeung CM

Project Title:	The effects of aldose reductase deficiency on retinal ischemic injury in diabetic db/db mice
Investigator(s):	Yeung CM, Lo ACY, Wong DSH
Department:	Eye Institute
Source(s) of Funding:	Small Project Funding
Start Date:	04/2009
Completion Date:	09/2009

Abstract:

The research direction of our project has been changed and the new project title is: The effects of Lycium barbarum polysaccharides on brain and retinal ischemic injuries in mice. Retinopathy is a common complication of diabetes. People with diabetic retinopathy also have increased risks of other systemic vascular complications such as stroke. As the disease progresses, regional failure of the microvascular circulation will lead to retinal ischemia. Retinal ischemic injury is therefore also common in patients with diabetes. Lycium barbarum, a Traditional Chinese Medicine, is well known for its beneficial effects (including nourishing the liver and kidney as well as improving the eyesight) in human. It has been previously shown that the extracts of Lycium barbarum exhibit cytoprotective effects on a number of different cell types including neurons. More recently, its neuroprotective effects on retinal ganglion cells have also been demonstrated. Based on these earlier studies, the aim of our present study is to evaluate the effects of Lycium barbarum polysaccharides (LBP) on brain and retinal ischemic injuries in order to further investigate its therapeutic potential in stroke and diabetic retinopathy. By using an in vivo mouse model of brain and retinal ischemia, the objectives of the present proposal are: 1.) To determine the neuroprotective effects of LBP on brain and retinal ischemic injuries 2.) To determine the potential therapeutic dosage(s) and time point(s) of LBP treatment 3.) To determine the possible mechanism(s)/pathway(s) involved in the neuroprotection by LBP

List of Research Outputs

Yeung C.M., Lo A.C.Y., Cheung A.K.H., Chung S.S.M., Wong D.S.H. and Chung S.K., More severe type 2 diabetes-associated ischemic stroke injury is alleviated in aldose reductase-deficient mice, Journal of Neuroscience Research. 2010, 88: 2026-2034.

Researcher : Yeung PKK

Project Title:	The Effectiveness of Vasopressin V1 receptor antagonist , SR49059, and V2 Receptor Anatongist, OPC-31260, on Cerebral Edema Formation in Endothelin-1-Overexpressed Mice
Investigator(s):	Yeung PKK, Chung SK
Department:	Anatomy
Source(s) of Funding:	Small Project Funding
Start Date:	09/2008

Abstract:

Brain edema is one of the complications and causes of death after stroke. Anti-edemic agents are, therefore, important in the treatment of stroke patients. Arginine vasopressin, a neuropeptide homone formed in the hypothalamus and transported via axons to and released from the posterior pituitary into the blood stream, has been reported to regulate astroglial cell volume in vitro. Experimental evidence also showed that vasopressin is responsible for both vasogenic and cytotoxic brain edema formation. Treatment with the vasopressin receptor antagonists has been found to prevent cerebral edema. Endothelin-1 (ET-1) is a potent vasoconstrictor originally isolated from aortic endothelial cells. In brain, astrocytic ET-1 was demonstrated playing a crucial role in pathogenesis of cerebral ischemic injury. Previously, our laboratory generated transgenic mice over-expressing endothelin-1 specifically in the astrocytes (GET-1 mice). GET-1 mice show more susceptible to brain damage, including increased cerebral edema, upon transient focal ischemia induced by middle cerebral artery occlusion (Lo et al. 2005). In the present study, we would like (1) to investigate the efficacy of the vasopressin V1 receptor antagonist, SR49059, and V2 receptor antagonist, OPC31260, on cerebral edema development in the transgenic mice under ischemic stroke condition. Since two types of edema, cytotoxic and vasogenic edema, are coexist during stroke, so our second goal is (2) to determine which vasopressin receptor V1 or V2 is responsible for a specific type of edema formation through pharmacological approach. Moreover, we would like (3) to pursue the mechanisms of astrocytic ET-1 induced cerebral edema formation in GET-1 mice. We hope our study will lead to a greater understanding to the stroke formation and the therapeutic use of drug for treating brain edema in stroke patient.

List of Research Outputs

Yeung P.K.K., Lo A.C.Y., Leung J.W.C., Chung S.S.M. and Chung S.K., Targeted overexpression of endothelin-1 in astrocytes leads to more severe cytotoxic brain edema and higher mortality, Journal of Cerebral Blood Flow & Metabolism. 2009, 29: 1891-1902.

Researcher : Yeung SC

List of Research Outputs

Chiu K., Yeung S.C., Ho Y.S., Lok C.K.M., Chan W., So K.F. and Chang R.C.C., IL-10 improves retinal ganglion cell survival in experimental glaucoma model via up-regulation of IGF-1 signaling, Hong Kong Society for Immunology 2010 Annual General Meeting and Scientific Meeting, April 17, 2010.. 2010, 14.

Chiu K., Yeung S.C., So K.F. and Chang R.C.C., Modulation of morphological changes of microglia and neuroprotection by monocyte chemoattractant protein-1 in experimental glaucoma, Cellular and Molecular Immunology. 2010, 7: 61-68.

Chiu K., Zhou Y., Yeung S.C., Lok C.K.M., Chan O.O.C., Chang R.C.C., So K.F. and Chiu J., Up-regulation of crystallins is involved in the neuroprotective effect of wolfberry on survival of retinal ganglion cells in rat ocular hypertension model, Journal of Cellular Biochemistry. 2010, 110: 311-320.

Researcher : Yik SY

List of Research Outputs

Ho Y.S., Yu M.S., Yik S.Y., So K.F., Yuen W.H. and Chang R.C.C., Polysaccharides from wolfberry antagonizes glutamate excitotoxicity in rat cortical neurons, Cellular and Molecular Neurobiology. 2009, 29: 1233-1244.

Researcher : Yip HKF

Project Title:	In vivo gene transfer of the catalytic subunit of telomerase protects retinal ganglion cells against axotomy-induced cell death
Investigator(s):	Yip HKF, Tsao GSW, Chung SK
Department:	Anatomy
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	05/2005

Abstract:

To compare TERT mRNA expression levels in axotomized mouse and fish RGCs; to determine whether TERT upregulation protects mouse RGCs from axotomy-induced cell death; to determine signaling pathways involved in the TERT-induced survival of axotomized RGCs.

Project Title:	Role of telomerase and telomere length in adult neurogenesis and repair of aging brain
Investigator(s):	Yip HKF, Tsao GSW, Ho SL, Zhou Z
Department:	Anatomy
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	04/2008
Completion Date:	09/2009

Abstract:

There is very little regenerative ability in the mature central nervous system (CNS) in response to injury, and yet with increasing age the brain is increasing vulnerable to injury from stroke and neurodegenerative disorder. The therapeutic approaches for age-related brain injury or disease have mainly focused on protecting the neurons at risks. These strategies have been developed based on the understanding of mechanisms of histopathology and designing treatments through pharmacological or gene therapy interventions. However, these therapeutic strategies are limited at best where substantial neuronal loss has already occurred. Age-related neurodegenerative diseases, such as Alzheimer’s disease and Parkinson’s disease, are characterized by progressive loss of neurons in specific areas of the brain. Stem cell therapy offers a potential therapeutic intervention to alleviating and possibly reversing the course of these diseases, either to replace lost neurons or as vehicles to deliver neuroprotective agents. However, application of stem cell therapy as a viable option to repair aging brain is complicated by the intrinsic cell properties and extrinsic environmental changes that occur during the natural course of aging. Although progress has been made toward replacement of damaged cells and recovery of function, there are still fundamental issues that need to be addressed before stem cell therapy can be applied successfully in the aging brain. Increasing evidence has demonstrated that neurogenesis is not entirely restricted in the developing nervous system, but continues throughout the adult life in specific regions of the brain of both rodents and humans (1). Active neurogenesis is found to be restricted to two regions of the adult mammalian brain (2-5), namely the subventricular zone (SVZ) surrounding the lateral ventricles and the subgranular Layer (SGL) in the dentate gyrus of the hippocampus. Neural stem cells (NSCs) have also been found in other brain regions (6,7,8,9,10). The NSCs derived from all these regions have the capacity for self-renew and multipotentiality in vitro (11,12). Neurogenesis in the adult brain have been demonstrated to be responsive to behavior and environmental changes, including aging, stress, stroke, seizure, physical activities, and dietary restriction (13-17). In addition, there is evidence to show that newly generated neurons can form appropriate anatomical connections and become functional integrated (18,19,20). The demonstration of neurogenesis in the human brain makes this phenomenon of particular relevance to treating degenerative neurological diseases or psychiatric disorders, with the hope that the ability to generate new neurons may be recruited for structural and functional repair. The rapid advances in adult NSC in recent years have greatly attained the goal in learning how to manipulate neural precursors toward therapeutic neuronal or glial replacement. Elucidation of the molecular regulations might offer both control over transplanted NSCs and the development of neuronal replacement therapies based on the recruitment of endogenous NSCs. However, a number of cellular and molecular changes alter the structure and function of the adult brain during the aging process could have a large impact on the function of NSCs. The production of new neurons in neurogenic brain regions decreases with increasing age (21,22). Accumulation of protein and lipid by-products, increased oxidative damage to proteins and DNA, and decreased metabolic activity could all impair function of normal neurons. Several growth factors and their receptors that are known to promote neuronal proliferation and survival, including brain-derived growth factor (BDNF) and insulin-growth factor-1 (IFG-1) also decline with age (23,24). The altered environment presumably contributes to the progressive loss of neurogenic capacity in the aging brain, which occurs even in the absence of disease. Together with the decline of proliferation in the hippocampus, there is also a decrease in differentiated progeny of hippocampal progenitor cells of aged rodents (21,25). In addition to environmental factors, intrinsic molecular changes in the NSCs themselves, such as subtle changes in cell replication processes, could contribute to decreased neurogenesis. Telomeres are non-codinig DNA sequences that cap the ends of chromosomes (26). Telomeres in all vertebrates are composed of same sequence of (TTAGGG) repeats (27). Telomere loss occurs with each round of DNA replication. As telomere length decreases with cell divisions as well as with age, the telomere can be used to predict future replicative capacity of cells (28). Normal somatic cells undergo a finite number of cell division before entering a non-dividing state called cellular senescence. The reduction in proliferation capacity of cells from old donors and patients with premature aging syndromes implicate cellular senescence in aging and age-related pathologies (29). The telomeres hypothesis proposes that telomere shortening in mitotic somatic cells contributes to and causes their senescence and underlies the aging process. This hypothesis suggests that if telomeres in somatic cells can be maintained at, or increased to, presenescent levels (e.g., via telomerase) then replicative life-span should increase as well. Thus, if cell senescence can be slowed or prevented, then age-related diseases may also be slowed or prevented (29,30). Telomeres can be elongated by the ribonucleoprotein enzyme telomerase, which adds tandem (TTAGGG)n repeats to the chromosome ends, using its own RNA as a template. Telomerase consists of an RNA portion and a protein component. Telomerase can compensate for the continual shortening of telomeres that would otherwise occur (31). Therefore, decreased neurogenesis may be the results of decreased proliferation or increase quiescence of NSCs or combination of both factors due to low telomerase activity. Recent evidence (32) and our preliminary results (appendix) suggest that in the adult brain, expression of telomerase and telomerase activity can be localized to neural progenitor cells of the SVZ and SGL, supporting the hypothesis that any age-related decrease of telomerase activity and telomerase expression could target NSCs and contribute to decreased neurogenesis and consequently decreased in respond to a destructive injury in the aging brain. In order to test these hypotheses, the following specific aims are proposed: 1. To determine whether telomerase expression, telomerase activity and telomere length change in the neurogenic regions (SVZ and SGL) of the adult mouse brain with aging. 2. To examine the effect of local cerebral ischemia on neurogenesis and migration of newborn neurons in the aged and young rodent brain.

Project Title:	Interactions between inhibitors of DNA binding (Id) and bone morphogenetic proteins (BMPs) in retinal cell specification
Investigator(s):	Yip HKF, Sham MH, Wong YC
Department:	Anatomy
Source(s) of Funding:	General Research Fund (GRF)
Start Date:	09/2008

Abstract:

(1) To establish expression patterns of BMPs and BMP receptors in the developing mouse retina; (2) To assess whether BMPs regulate Id expression and induce changes in normal growth of the developing mouse retina; (3) To assess whether the upregulation of Ids are Smad-dependent; (4) To assess the effect of Ids on the function of proneuronal bHLH and neurogenesis of retinal precursor cells.

Project Title:	Telomerase immortalization of retinal ganglion cells derived from the embryonic mouse retinal progenitor cells
Investigator(s):	Yip HKF, Tsao GSW
Department:	Anatomy
Source(s) of Funding:	Small Project Funding
Start Date:	01/2009

Abstract:

The central nervous system (CNS) is made up of a vast diversity of neurons and glia with different phenotypes, each with its own ontogeny. Neurons in particular are classified by distinct expressed receptors, secreted neuro-transmitters, physiological properties and patterns of connectivity that define both the anatomy and function of distinct neuronal populations. However, there are only a few of these neuronal phenotypes generated from embryonic stem cells, which include motor neurons and dopaminergic neurons (1, 2). For the neuronal and glial phenotypes of the CNS, tissue is the only reliable source of defined neuronal subpopulations or their progenitor cells. In order to establish homogenous population of phenotypically defined neurons and glia, it is necessary to isolate and expand defined populations of progenitors, either from fetal or adult CNS. Neural progenitor cells are useful in potential cell replacement therapy for neuro-degenerative diseases. During retinal development, the retinal epithelium derives from the diencephalon bulges to form the optic vesicle. The distal part of the vesicle invaginates, the resulting inner layer becomes the retinal ventricular zone, which gives rise to the neuroretina. On the other hand, the outer proximal layer forms the retinal pigment epithelium. The inner layer consists of actively proliferating progenitors close to the sub-retinal space (a derivative of third ventricle). During retinogenesis, the early generation of retinal progenitors is followed by the migration of cells from their proliferation sites to their destinated areas where increasing number of post-mitotic cells are generated. Progenitors of the retina give rise to seven types of cells, including six types of neurons and the Müller glia cells. It is well established that all retinal cells are derived from a common type of progenitors (3). In the mouse retina, cell differentiation begins at embryonic day (E) 10.5 with the appearance of first post-mitotic retinal ganglion cells (RGCs), forming the ganglion cell layer close to the vitreous body. This is followed by the gradual differentiation of horizontal and amacrine cells as well as cone receptors. The rod receptors, bipolar cells and Müller cells are generated towards the end of retinogenesis. As retinogenesis proceeds, successive generation of neurons and Müller glia cells occurs in an overlapping and yet strictly temporal sequence that is generally conserved across all vertebrate species (4). The precise mechanisms by which multipotential retinal progenitors give rise to different retinal cell types remain to be elucidated. Cells that make up the adult organs and tissues, including CNS, arise from dividing progenitor cells, which themselves derive from mutlipotential stem cells. Stem cells express telomerase, which allows cells to divide by maintaining the length of chromosomal telomeres. When telomerase level falls, telomeric shortening occurs and cell division and expansion stops. Telomerase activity typically decreases to undetectable level in neural progenitors during the later stages of development. In the CNS, examples of phenotypically restricted progenitors include those for motor neurons, midbrain dopaminergic neurons, basal forebrain cholinergic neurons and oligodendrocytes (5). These clinically important cell types have very limited capacity for mitotic expansion due to, at least in part, their loss of telomerase expression. The decline in telomerase activity during development reflects the transcriptional inactivation of TERT, the rate-limiting enzyme of the telomerase complex (5). On this basis, TERT has been over-expressed in several differentiated cell types as a means of maintaining their mitotic competence. Thus, through TERT over-expression, telomerase-immortalized lines of dermal fibroblasts, endothelial cells, osteoblasts, stromal cells and retinal pigment epithelial cells have been generated (6). There are no reports of increased incidence of neoplasia or neoplastic transformation in these cell lines (7, 8). Thus, telomerase over-expression has been successful to establish uniform and self-renewing lines of cells which maintain their phenotypes with expansion and are therapeutically relevant. On this basis, we ask the question whether TERT overexpression can be used to establish lines of phenotypically restricted cells derived from mouse retinal progenitor cells. In the process of forming visual images, the brain decodes and interprets the visual images that we perceive when electrical impulses generated within the retina are transmitted by RGCs through the optic nerve to the visual cortex of the brain. Progressive death of RGCs occurs in glaucoma and several other retinal diseases (9), which can lead to visual impairment and blindness. Primary RGC cultures have been successfully established from neonatal retinas (10), however, the number of viable RGCs declines rapidly within a short time for any meaningful long-term experimentation. In order to circumvent the problems of number of viable cells and the time-consuming process of culturing primary RGC, permanent RGC cell line may provide a useful tool to evaluate RGC biology and developmental signals in the differentiation of RGCs from the retinal progenitor cells. Knowledge from these studies will provide the basis for designing cell replacement therapy in RGC-related diseases. Toward this end, we propose the following objective: Objective: 1. To establish TERT-immortalized RGC cell lines from retinal progenitor cells isolated from mouse embryonic retina. References: 1. Wichterle, H et al (2002) Cell 110:385-97. 2. Roy, NS et al (2006) Nat. Med. 12:1259-68. 3. Turne, DL (1990) Neuron 4:833-45. 4. Cepko CL et al (1996) PNAS USA 93:589-95. 5. Wright, W et al (1996) Dev. Genetics 18:173-79. 6. Bodnar AG et al (1998) Science 279:349-52. 7. Jiang, XR et al (1999) Nat. Genet. 21:111-14. 8. Morales C et al (1999) Nat. Genet. 21:115-18. 9. Quigley HA et al (1995) Invest. Ophthalmol. Vis. Sci. 36:774-86. 10.Barres, BA et al (1988) Neuron 1:791-803.

Project Title:	Telomerase acts downstream of brain-derived neurotrophic factor signaling in neural progenitor cells isolated from the aged mouse brain
Investigator(s):	Yip HKF, Tsao GSW, Zhou Z
Department:	Anatomy
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	04/2010

Abstract:

The endogenous generation of new neurons in the adult mammalian brain, derived from neural stem cells (NSCs) (1), has raised the hope that NSCs may be recruited for structural brain repair. As there is evidence that endogenous neurogenesis can contribute to functional neural circuitry (2,), it is hoped that NSCs can be manipulated to similarly contribute to injured regions. While these newly generated neurons are capable of functioning and participated in established circuitry, this contribution is, however, insufficient to completely restore the injured region. It has been shown that injury itself can generate an increase in neurogenesis within the neurogenic regions, probably due to an increase of local expression of growth factors (3). Quiescent NSCs are stimulated to proliferate, migrate to the site of injury and differentiate to be incorporated into local neural network, thereby regenerating damaged areas. Although the recruitment of endogenous NSCs in response to injury does not lead to substantial recovery, these observations offer encouragement that it may be possible to develop therapeutic strategies that increase the limited response. Such approaches may include growth factor administration. In addition to the intrinsic properties of stem cells, changes of external environment, such as growth factor levels, can also contribute to the decline in adult NSC function during aging (4). Many growth factors have been identified that can promote the proliferation, differentiation and/or survival of NSCs. For example, neurotrophins are growth factors that are best known for playing vital roles in the survival and differentiation of neurons, but also regulate development of NSCs. Brain-derived neurotrophic factor (BDNF), a member of the neurotrophin family, along with its preferred tyrosine kinase receptor, TrkB is expressed in the neurogenic regions during the period of neurogenesis (5). BDNF promote its neurotrophic effects by activating TrkB receptor. However, the underlying mechanisms of BDNF/TrkB signaling involved in NSC biology have not been fully established. Studies have indicated that neuroprotection afforded by BDNF/TrkB is mediated by extracellular signal-regulated kinase 1/2 (ERK1/2) and phosphatidylinositol-3 kinase (PI3K) pathway (6). BDNF are capable of activating endogenous NSCs and increase neurogenesis in adult brain (7). The mechanisms downstream of ERK1/2 and PI3K that lead to NSC survival are less clear. There is increasing evidence that aging occurs in adult NSCs. Although adult NSCs retain their multipotentiality even into old age, deficits in the regenerative process occur as a function of age, some of which may be due to decline in stem cell proliferative capacity (8). The inability to maintain the NSC pool throughout aging suggests that an eventual decrease in the efficiency of self-renewal such that NSC loss during aging is not fully compensated. One of the better known intrinsic factors associated with aging is the progressive shortening of telemeres and decrease in TERT activity which are implicated to cause replicative senescence of NSCs with age (9). Cells maintain their telomeres by the action of telomerase. Decrease in telomerase activity results in telomere shortening, leading to telomere loss and chromosomal instability, as well as cellular senescence (10). Over-expression of telomerase prevents cellular senescence and extends life span of cultured cells (11), demonstrating a crucial role of telomerase in cell replication. Telomerase is well known for the maintenance of pluripotential differentiation and the proliferative capacity of embryonic NSCs (12). The presence of telomerase in adult NSCs suggests a functional role of telomerase in these cells. Although telomerase activity is associated with self-renewal potential in stem cells (13) and show gradual loss throughout life, it is unclear whether decreased telomerase expression causes declines in NSC function during aging. We speculate that decrease in telomerase activity may lead to replicative senescence in NSCs with increasing age, and contribute to the decline in NSC activity and injury response in aged brain. Recently, TERT has also emerged as a molecule involved in proliferative potential and survival of hair follicle and epidermal stem cells, which operates through a mechanism independent of its action in telomere lengthening and telomerase activity (14,15). However, little is known as to how telomerase activity in NSC is regulated. Thus it would be interesting to investigate the potential involvement of TERT independently of telomere synthesis in NSC function in the aging mouse brain. Recently, studies have shown that BDNF stimulates telomerase activity and gene expression in developing neurons (16). In addition, both BDNF and telomerase activity are upregulated after ischemic brain injury (17,18). Together, these observations raised the possibility that transient ischemia leads to an increased level of BDNF in the brain which upregulates the level of telomerase expression in NSCs and might account for the increased neurogenesis following cerebral ischemia. Neurogenesis in response to brain injury, although it may occur in some brain regions, is inadequate to allow functional recovery. Thus strategies are being sought to amplify this endogenous regenerative response. Whether or not BDNF regulates telomerase activity in NSCs and to what extent BDNF regulates stem cell aging by modulating telomerase activity are unknown and are the main focus of the present study. Objective: 1. To assess whether BDNF can enhance the decreased capacity of aged NSCs by upregulating telomerase through the activation of the PI3K/Akt and MAPK/ERK1/2 pathways. References: 1. Gage FH (2002) J Neurosci 22:612-613. 2. van Praag H et al (2002) Nature 415:1030-1034. 3. Hallbergson NJ et al (2003) J Clin Invest 112:1128-1133. 4. Fukumitsu H et al (2006) J Neurosci 26:13218-13230. 5. Hetman M et al (1999) JBC 274:22569-22580. 6. Rando TA (2006) Nature 441:1080-1086. 7. Benraiss A et al (2001) J Neurosci. 21:6718-6731. 8. Kuhn HG et al (1996) J Neurosci 16: 2027-2033. 9. Molofsky AV et al (2006) I Nature 443:448-452. 10. Blackburn EH (2000) Nature 408:53-56. 11. Bodnar AG et al (1998) Science 279:349-352. 12. Haik S et al (2000) Oncogene 19:2957-2966. 13. Morrison SJ et al (1996) Immunity 5:207-216. 14. Sarin KY et al (2005) Nature 436:1048-1052. 15. Flores I et al (2005) Science 309:1253-1256. 16. Fu W et al (2002) J Neurosci 22:10710-10719. 17. Tsukahara T et al (1998) Neurochem Int 33:201-207. 18. Kang HJ et al (2004) J Neurosci 24:1280-1287.

Project Title:	Combined treatment of lithium and noggin inhibits astroglios after spinal cord injury by deactivation of GSK-3β/STAT3 are BMP/Smad pathways in the endogenous adult neural stem cells
Investigator(s):	Yip HKF, Shum DKY
Department:	Anatomy
Source(s) of Funding:	Spinal Cord Injury Research Grant
Start Date:	05/2010

Abstract:

List of Research Outputs

Du Y. and Yip H.K.F., Bone Morphogenetic Protein Signaling Activates Id Genes in the Mouse Retinal Progenitor Cells, Hellenic Society for Neuroscience. 2009.

Du Y. and Yip H.K.F., Differentiation plasticity of neural stem cells in the injured adult mouse spinal cord is regulated by bone morphogenetic proteins (BMPs), Hellenic Society for Neuroscience. 2009.

Du Y. and Yip H.K.F., Effects Of Bone Morphogenetic Protein 2 On Id Expression And Neuroblastoma Cell Differentiation, Differentiation. Elsevier, 2010, 79: 84-92.

Fu Q., Li X., Yip H.K.F., Shao Z.H., Wu W., Mi X. and So K.F., Combined effect of brain-derived neurotrophic factor and LINGO-1 fusion protein on long-term survival of retinal ganglion cells in chronic glaucoma, Neuroscience Bulletin. 2009, 25(1): 171-172.

Liu M., Wu G. and Yip H.K.F., Expression of TERT and Telomerase aactivity in the rat central nervous system during aging, the University of Hong Kong Li Ka Shing Faculty of Medicine, Research Centre of Heart, Brain, Hormone & Healthy Aging, 5th International Symposium on Healthy Aging. 2010.

Liu M. and Yip H.K.F., The expression of TERT and Id2 in the subventricular zone and neural stem cells in adult mouse, 15th Research Postgraduate Symposium, The University of Hong Kong, Li Ka Shing Faculty of Medicine. 2009.

Niu C. and Yip H.K.F., Brain-derived neurotrophic factor (BDNF) regulates telomerase neuroprotective activity through activation of ERK1/2/C-Myc and PI3K/Akt/NFκB pathways in rat spinal cord motor neurons, the University of Hong Kong Li Ka Shing Faculty of Medicine, Research Centre of Heart, Brain, Hormone & Healthy Aging, 5th International Symposium on Healthy Aging. 2010.

Niu C. and Yip H.K.F., Telomerase Expression And Activity Promote Retinal Ganglion Cell Survival After Optic Nerve Injury, US Society of Neuroscience Annual Meeting. 2009.

Niu C., Tsao G.S.W. and Yip H.K.F., The anti-apoptotic role of telomerase in spinal cord motor neurons, 15th Research Postgraduate Symposium, The University of Hong Kong, Li Ka Shing Faculty of Medicine. 2009.

Xiao Q., Du Y., Wu W. and Yip H.K.F., Bone Morphogenetic Proteins Mediate Cellular Response And, Together With Noggin, Regulate Astrocyte Differentiation After Spinal Cord Injury, Experimental Neurology. Elsevier, 2010, 221: 353-366.

Xiao Q. and Yip H.K.F., Differentiation plasticity of neural stem cells in the injured adult mouse spinal cord is regulated by bone morphogenetic proteins (BMPs), USA Society of Neuroscience Annual Meeting. 2009.

Yip H.K.F. and Du Y., Activation Of Id Genes By Bmp Signaling Influences Proliferation And Cell Fate Choices Of Retinal Progenitors, The Association for Research in Vision and Ophthalmology Annual Meeting. 2010.

Researcher : Yip YL

Project Title:	Study of the immortalization of nasopharyngeal epithelial cells by EBV-encoded latent membrane protein 1
Investigator(s):	Yip YL, Tsao GSW
Department:	Anatomy
Source(s) of Funding:	Small Project Funding
Start Date:	09/2008
Completion Date:	02/2010

Abstract:

Nasopharyngeal carcinoma (NPC) is commonly occurred among Southern Chinese and is the third most common cancer in Southern China. Epstein-Barr virus (EBV) infection has been postulated to play a role in the pathogenesis of NPC. Infection of EBV can be detected in the premalignant lesions of nasopharyngeal epithelium. Cell immortalization is a common property of cancer cells and is generally regarded as an early and pre-requisite step in carcinogenesis. Immortalization of nasopharyngeal epithelial (NP) cells will provide premalignant NP cell systems, which are relevant for study of early events in NPC tumorigenesis. Our laboratory has been involved in the immortalization of NP cells and characterization of the underlying genetic and cellular events. Telomerase is commonly expressed in immortal and cancer cells. It plays an important role in maintaining telomeric length, stabilizing the chromosomes for continuous cell division. Our laboratory has reported that activation of telomerase is common in NPC and can be detected at high frequency in stage I NPC (Cheng et al., British Journal of Cancer, 77(3):456-460, 1998). Telomerase activation may be an early event in tumour progression. We have established an immortalized NP cell line by using telomerase alone (Li et al., International Journal of Cancer, 119:1567-1576, 2006). We found that immortalization of NP cells using telomerase alone is not efficient and requires additional genetic alterations. Latent membrane protein 1 (LMP1) is an oncogene encoded by EBV. In B-lymphocytes, overexpression of LMP1 upregulates cell surface markers and protects cells from apoptosis. In epithelial cells, LMP1 overexpression inhibits differentiation. LMP1 is transforming in rodent fibroblast cell lines (Young and Murray, Oncogene, 22(33):5108-5121, 2003). It is believed to interact with pre-existing genetic alterations in premalignant lesions of nasopharyngeal epithelium, transforming premalignant cells into invasive cancer cells. Interestingly, LMP1 expression could be detected in premalignant nasopharyngeal lesions (Pathmanathan et al., New England Journal of Medicine, 333(11):693-698, 1995) but not expressed in all the NPC samples tested (Stevenson et al., Cancer Research, 65(19):8826-8835, 2005). Expression of LMP1 may be essential in the early stage of development of NPC in promoting cell growth but dispensable at the later stage of NPC development. LMP1 can activate a number of signaling pathways. Our laboratory has been involved in the investigation of signaling pathways involved in the function of LMP1 on NP cells. We have shown that expression of LMP1 inactivates RASSF1A, which is a tumor suppressor gene commonly inactivated in NPC (Man et al., Oncogene, 26(21):3069-3080, 2007). We have demonstrated that overexpression of LMP1 leads to upregulation of Id-1 (Li et al., Oncogene, 23(25):4488-4494, 2004), which is a common event for the cells to escape cellular senescence. In NPC cells, we have shown that overexpression of Id-1 downregulates p16 (Wang et al., Molecular Carcinogenesis, 35(1):42-49, 2002). The p16 gene is known to play a key role in induction of cellular senescence. Inactivation of the p16 is a common event in immortalization of many types of human cells and about half of the nasopharyngeal carcinomas showed inactivation of the p16 gene (Kwong et al., Clinical Cancer Research, 8:131-137, 2002). Recently, LMP1 was shown to upregulate Bmi-1 in Hodgkin lymphoma (Dutton et al., Blood, 109:2597-2603, 2007). Overexpression of Bmi-1 is common in human cancer including NPC (Song et al., Cancer Research, 66:6225-6232, 2006). Bmi-1 plays a role in overcoming cellular senescence through suppressing the expression of p16 and activating telomerase in cells. Expression of Bmi-1 has been shown to immortalize one NP cell line (Song et al., Cancer Research, 66:6225-6232, 2006). Our laboratory has been involved in immortalization of NP cells by Bmi-1 and the immortalization process appears to be more efficient in the presence of telomerase (unpublished data). While immortalization of NP cells by telomerase alone is inefficient, it would appear that LMP1, through its alterations of cell signaling and other genes expression may be able to supplement some of the events required for immortalization. All these have prompted us to study the involvement of LMP1 in immortalization of NP cells. I have attempted to establish immortalized NP cells by expression of LMP1 alone or in combination with telomerase activation. Immortalization using these two components provides the cellular context for the NPC carcinogenesis study. Retroviral vector expression has been employed for expression of LMP1 and reconstitution of telomerase. Preliminary result showed that LMP1 expression could greatly extend the lifespan of cells. In combination with telomerase activation, one of the cell lines (NP361) got immortalized (Figures 1A, 1B). There are two major functional domains in the carboxyl-terminal cytoplasmic region of LMP1, namely CTAR1 and CTAR2, which are important in activating key cellular signaling pathways. We have obtained several LMP1 mutants of these domains. In this study, we propose to examine the major properties of LMP1 involved in extension of life span and immortalization using the various LMP1 mutants. One important event we observed in the immortalized NP361 cells is the upregulation of EGFR (Figure 1C). EGFR has been reported to be involved in immortalization of human keratinocytes (Akerman et al., Cancer Research, 61:3837-3843, 2001). In NPC, EGFR is overexpressed (Zheng et al., European Journal of Cancer Part B: Oral Oncology, 30B:290-295, 1994). Previous study showed that LMP1 expression could induce EGFR expression (Miller et al., Journal of Virology, 69:4390-4398, 1995). MAPK and PI3K are the two major signaling pathways response to EGFR signaling. In our immortalized cells, activation of MAPK signaling molecules (MEK1 and ERK1/2) and Akt, which was downstream of the PI3K, could be observed. We will study if EGFR will co-operate with LMP1 in immortalization of NP361 cells. We will examine if the immortalization can be achieved at a much higher efficiency and shorter time interval. Previous study from our laboratory showed that LMP1 expression could induce anchorage independent growth of an SV40T immortalized NP cells in soft agar but not tumorigenic growth in immune suppressed mice (Tsao et al., Seminars in Cancer Biology, 12:473-487, 2002). In fact, the immortalized NP361 cells are not able to undergo anchorage independent growth in soft agar and are non tumorigenic when injected into nude mice. Other oncogenes, such as Ras, may be required for the tumorigenic transformation of cells. Our preliminary study showed that expression of H-Ras in a telomerase-immortalized NP cell line could lead to colonies formation in soft agar and tumor formation in nude mice (Figure 2). We will examine whether the immortalized NP361 cells are more susceptible to malignant transformation using oncogenes, including Ras. Specific objectives are: (1) To identify the functional domains of LMP1 involved in extension of life span and immortalization of NP cells. (2) To study the role of EGFR in the immortalization of NP cells by LMP1. (3) To examine if the immortalized NP cells are more susceptible to tumorigenic transformation.

List of Research Outputs

Tsang C.M., Zhang G., Seto E., Takada K., Deng W., Yip Y.L., Man C.W.Y., Hau P.M., Chen H., Cao Y., Lo K.W., Middeldorp J.M., Cheung A. and Tsao G.S.W., Epstein-Barr virus infection in immortalized nasopharyngeal epithelial cells: Regulation of infection and phenotypic characterization. , International Journal of Cancer. 2010, 127: 1570-1583.

Tsang C.M., Zhang G., Seto E., Takada K., Deng W., Yip Y.L., Man C.W.Y., Hau P.M., Cao Y., Lo K.W. and Middeldorp J.M., Epstein-Barr virus infection in immortalized nasopharyngeal epithelial cells: Regulation of infection and phenotypic characterization, Int. J. Cancer. 2010, 127: 1570-83.

Tsao G.S.W., Tsang C.M., Zhang G., Deng W., Hau P.M., Man C.W.Y., Kenzo T., Chen H., Yip Y.L., Lo K.W., Cao Y. and Cheung A., Epstein-Barr virus infection confer stress-resistant property in immortalized nasopharyngeal epithelial cells., Proceedings of American Association of Cancer Research. 2010.

Yip Y.L., Tsang C.M., Jin Y., Deng W., Man C.W.Y., Cheung P.P.Y., Chen H., Cheung A. and Tsao G.S.W., The Epstein-Barr virus-encoded LMP1 extended the life span and immortalized nasopharyngeal epithelial cells., Hong Kong International Cancer Congress . 2009.

Researcher : Young W

List of Research Outputs

Young W. and So K.F., Current status of spinal cord injury research, 7th AMN Congress and 16th Annual Scientific Meeting of HKNS, Nov. 12-14, 2009, Hong Kong. 2009, 82.

Researcher : Yu MS

Project Title:	Significance of FADD phosphorylation in neurodegeneration: regulation of aberrant cell cycle events in oligomeric beta-amyloid peptides-induced neuronal apoptosis?
Investigator(s):	Yu MS, Chang RCC
Department:	Anatomy
Source(s) of Funding:	Small Project Funding
Start Date:	10/2008
Completion Date:	03/2010

Abstract:

The purpose of this proposed project is to investigate the significance of phosphorylation of Fas-Associated Death Domain-containing protein (FADD) in oligomeric beta-amyloid (Aβ) peptide-induced neuronal apoptosis; and whether FADD-P (the phosphorylated form of FADD) plays an important role in the regulation of aberrant cell cycle events under the neurotoxicity of oligomeric Aβ peptides. Alzheimer’s disease (AD) is an age-related, chronic, irreversible and fatal neurodegenerative disorder pathologically characterized by the senile plaques (extracellular deposits of Aβ peptides), neurofibrillary tangles (intracellular hyperphosphorylated tau proteins) and massive neuronal loss. Conventionally, fibrillar (or insoluble) form of Aβ peptides was believed to exert toxic effects to neurons, consequently initiated apoptosis and finally resulted in neurodegeneration in AD. In the recent years, increasing lines of evidence have proved that the oligomeric (or soluble) form of Aβ peptides is a more potent initiator to trigger neurodegeneration in AD. In addition, ectopic cell cycle activation preceding neurodegeneration as well as plaque and tangle formation has been observed in AD brains. Thus, understanding of the molecular mechanism of the aberrant cell cycle events in oligomeric Aβ-induced apoptosis would lead us getting more insights on the pathogenesis of AD. The underlying mechanism(s) of the signaling pathway leading to the two classical pathological hallmarks, i.e. plaques and tangles, and neuronal loss is still unclear. Our previous findings have proved the involvement of PKR-eIF2α (double-strand RNA activated protein kinase and its substrate, eukaryotic initiation factor 2 alpha) signaling in both cultured cortical neurons and post-mortem AD brain sections (Chang et al, 2002a, 2002b). We have also shown that Aβ-induced apoptosis is independent of the unfolded protein responses (Yu et al, 2006). Recently, we have extended our study by exploring the possible involvement of death receptor signaling in the activation of PKR. FADD is a death receptor adaptor involved in the classical death receptor (Fas/TNFR1) signaling pathway by forming the death-inducing signaling complex (DISC), which leads to apoptosis via the activation of caspase-8 and -3. Previous findings have shown that the levels of FADD-P were increased in cancer cells during apoptosis induced by taxol (Shimada et al, 2004). We have then elucidated the expression of FADD/FADD-P in Aβ-triggered neuronal apoptosis as well as in APP transgenic mouse model. Without obvious alteration in total FADD, to our surprise, the protein level of FADD-P was abundant in both untreated neurons and wild type mice brains. In contrast, Aβ-treated neurons or APP transgenic mice brains exhibited reduced level of FADD-P (Please refer to Fig. 1, 2 and 4 in Preliminary Data in Attachment). Our data indicated that the neurotoxic Aβ peptides may cause neurodegeneration via down-regulation of FADD-P, thus suggesting a protective nature of FADD-P in neurons. Unlike FADD, FADD-P is closely related to cell cycle regulation rather to the death receptor signaling pathway. FADD-P was found in prostate cancer cells (LNCaP and DU145) and breast cancer cells (MCF-7) arrested at G2/M phase (Shimada et al, 2005; Matsuyoshi et al, 2006). There are two kinases responsible for FADD phosphorylation: FIST/HIPK3, a Fas/FADD-interacting serine/threonine kinase (Rochat-Steiner et al, 2000) and CK1α, the casein kinase 1 alpha (Alappat et al, 2005). Most of the studies related to FADD-P were carried out mainly in different cancer cell lines. However, little is known for the role of FADD-P and its downstream effects in neurons. Thus, it is our goal to explore the functional role of FADD-P in the nervous system. Increasing lines of evidence have suggested that ectopic cell cycle activation may be a prerequisite for neuronal cell death in post-mitotic neurons in AD. In vivo and in vitro studies have shown the existence of cell cycle re-entry (bypass G0/G1 and enter S phase), mitotic failure and eventual cell death (Herrup et al, 2004). However, cell cycle re-entry into G0/G1or S/G2 phases occurred in healthy aging brains, indicating that ‘mitotic failure or G2/M arrest’ may play a role in AD pathogenesis (Nagy, 2007). Recent studies have revealed an increase in CIP-1-associated regulator of cyclin B (CARB), a protein that associated with p21 and cyclin B at G2/M transition, in AD brain sections (Zhu et al, 2004). In addition, premature centromere division of the X chromosome (PCD,X), a mitotic failure event, was markedly elevated in AD brains (Spremo-Potparevic et al, 2008). All these findings further support us to hypothesize that mitotic failure at G2/M phase may be the leading cause of neurodegeneration in AD and phosphorylation of FADD may play significant roles in modulating this event. Owing to its cell cycle-related property, we aim to investigate the significance of FADD-P in the aberrant cell cycle events as well as apoptosis under the challenge of oligomeric Aβ1-42 in cortical neurons. To accomplish our goal, we have set the following specific aims: 1. To investigate the involvement of aberrant cell cycle events, especially the involvement of G2/M arrest-related proteins, triggered by oligomeric Aβ peptides; 2. To elucidate the significant roles of FADD-P in G2/M arrest-related event and its role in protecting neurons against Aβ toxicity; 3. To investigate the possible mechanisms of FADD-P in aberrant cell cycle events and apoptosis induced by oligomeric Aβ toxicity. The results obtained from this proposed project should provide information underlying the signaling pathway of oligomeric Aβ peptides-induced neurodegeneration, thus highlighting the potential of targeting FADD-P and cell-cycle related proteins in AD. References Alappat et al, 2005, Phosphorylation of FADD at serine 194 by CKIalpha regulates its nonapoptotic activities. Mol Cell., 19, 321-332. Chang et al, 2002a, Involvement of double-stranded RNA-dependent protein kinase and phosphorylation of eukaryotic initiation factor-2alpha in neuronal degeneration. J Neurochem., 83, 1215-1225. Chang et al, 2002b, Phosphorylation of eukaryotic initiation factor-2alpha (eIF2alpha) is associated with neuronal degeneration in Alzheimer's disease. Neuroreport, 13, 2429-2432. Herrup et al, 2004, Divide and die: cell cycle events as triggers of nerve cell death. J Neurosci., 24, 9232-9239. Matsuyoshi et al, 2006, FADD phosphorylation is critical for cell cycle regulation in breast cancer cells. Br J Cancer, 94, 532-539. Nagy, 2007, The dysregulation of the cell cycle and the diagnosis of Alzheimer's disease. Biochim Biophys Acta., 1772, 402-408. Rochat-Steiner et al, 2000, FIST/HIPK3: a Fas/FADD-interacting serine/threonine kinase that induces FADD phosphorylation and inhibits fas-mediated Jun NH(2)-terminal kinase activation. J Exp Med., 192, 1165-1174. Shimada et al, 2004, Phosphorylation of FADD is critical for sensitivity to anticancer drug-induced apoptosis. Carcinogenesis, 25, 1089-1097. Shimada et al, 2005, Phosphorylation status of Fas-associated death domain-containing protein (FADD) is associated with prostate cancer progression. J Pathol., 206, 423-32. Spremo-Potparevic et al, 2008, Premature Centromere Division of the X Chromosome in Neurons in Alzheimer Disease. J Neurochem., available online on 9 Jul 2008. Yu et al, 2006, Beta-amyloid peptides induces neuronal apoptosis via a mechanism independent of unfolded protein responses. Apoptosis, 11, 687-700. Zhu et al, 2004, Elevated expression of a regulator of the G2/M phase of the cell cycle, neuronal CIP-1-associated regulator of cyclin B, in Alzheimer's disease. J Neurosci Res., 75, 698-703.

List of Research Outputs

Chang R.C.C., Ho Y.S., Yu M.S. and So K.F., Medicinal and nutraceutical uses of wolfberry in preventing neurodegeneration of Alzheimer's disease, In: Charles Ramassamy and Stéphane Bastianetto, Recent Advances on Nutrition and the Prevention of Alzheimer's Disease, 2010. Kerala, India, Transworld Research Network, 2010, 169-185.

Chang R.C.C., Chao J., Yu M.S. and Wang M., Neuroprotective effects of oxyresveratrol from fruit against neurodegeneration in Alzheimer's disease, In: Charles Ramassamy and Stéphane Bastianetto, Recent Advances on Nutrition and the Prevention of Alzheimer's Disease, 2010. Kerala, India, Transworld Research Network, 2010, 155-168.

Chao J., Lau K.W., Huie M.J., Ho Y.S., Yu M.S., Lai S.W., Wang M., Yuen W.H., Lam W.H., Chan T.H. and Chang R.C.C., A pro-drug of the green tea polyphenol (-)-epigallocatechin-3-gallate (EGCG) prevents differentiated SH-SY5Y cells from toxicity induced by 6-hydroxydopamine, Neuroscience Letters. 2010, 469: 360-364.

Chao J., Li H., Cheng K.W., Yu M.S., Wang M. and Chang R.C.C., Neuroprotective effects of methylated resveratrols in an vitro Parkinson's disease model , Society for Neuroscience 2009. Program No. 144.2: Poster No. G10.

Chao J., Cheng K.W., Yu M.S., Chang R.C.C. and Wang M., Protective effect of pinostilbene, a resveratrol methylated derivative against 6-hydroxydopamine-induced neurotoxicity in SH-SY5Y Cells, Journal of Nutritional Biochemistry. 2010, 21: 482-489.

Chao J., Li H., Cheng K.W., Yu M.S., Wang M. and Chang R.C.C., Resveratrol methylated derivatives as neuroprotective agents in 6-hydroxydopamine-induced SH-SY5Y cells, 5th International Symposium on Healthy Aging. 2010, Page 53.

Cheung Y.T., Zhang N.Q., Hung C.H.L., Lai S.W., Yu M.S. and Chang R.C.C., Autophagy may protect neurons from low molecular weight beta-amyloid peptide-induced apoptosis, 5th International Symposium on Healthy Aging. 2010, Page 58.

Cheung Y.T., Zhang Q., Hung H.L., Lai S.W., Yu M.S., So K.F. and Chang R.C.C., Investigating the temporal transition of autophagy and apoptosis in neurons stressed by low molecular weight beta-amyloid peptide toxicity, 11th International Geneva/Springfield Symposium on Advances in Alzheimer Therapy, March 24-27, 2010 Geneva. 2010, 42.

Ho Y.S., Yu M.S., Yang X., So K.F., Yuen W.H. and Chang R.C.C., Neuroprotective effects of polysaccharides from wolfberry, the fruits of Lycium barbarum. against homocysteine-induced toxicity in rat cortical neurons, Journal of Alzheimer's Disease. 2010, 19: 813-827.

Ho Y.S., Yang X., Yu M.S., So K.F. and Chang R.C.C., Polysaccharides from Wolfberry (Lycium barbarum) antagonize homocysteine-induced neurotoxicity in cultured cortical neurons, Society for Neuroscience 2009. Program No. 626.3: Poster No. H16.

Ho Y.S., Yu M.S., Yik S.Y., So K.F., Yuen W.H. and Chang R.C.C., Polysaccharides from wolfberry antagonizes glutamate excitotoxicity in rat cortical neurons, Cellular and Molecular Neurobiology. 2009, 29: 1233-1244.

Yu H.T., Chan W.W.L., Chai K.H., Lee C.W.C., Chang R.C.C., Yu M.S., McLoughlin D.M., Miller C.C.J. and Lau K.F., Transcriptional regulation of human FE65, a ligand of Alzheimer's disease amyloid precursor protein, by Sp1, Journal of Cellular Biochemistry. 2010, 109: 782-793.

Researcher : Yu WY

List of Research Outputs

Li S.Y., Yeung C.M., Yu W.Y., Chang R.C.C., So K.F., Wong D.S.H. and Lo A.C.Y., Protection Of Retinal Neurons By Administration Of Lycium Barbarum (wolfberry) In A Murine Model Of Acute Ischemia/reperfusion Injury, Joint Annual Scientific Meeting of the Hong Kong Society of Neurosciences and the Biophysical Society of Hong Kong. 2010.

Researcher : Yuan T

List of Research Outputs

Arias-Carrion O. and Yuan T., Autologous neural stem cell transplantation: A new treatment option for Parkinson's disease?, Medical Hypotheses. 2009, 73(5): 757-759.

Li J., Gao G.D. and Yuan T., Cell based vaccination using transplantation of iPSC-derived memory B cells, Vaccine. 2009, 27: 5728-5729.

Yuan T., Liang Y., Tay D.K.C., So K.F. and Ellis-Behnke R.G., Olfactory tract transection enhances adult neurogenesis in piriform cortex, 22nd Biennial Meeting of the International Society of Neurochemistry, Busan Korea. 2009.

Yuan T., Self-assembling peptide nanofiber scaffold treatment to acutely injured olfactory bulb. 2009, 95 pages.

Researcher : Zhang E

List of Research Outputs

Zhang E., Yau S.Y., Lau W.M., So K.F. and Chang R.C.C., Anti-depressive effects of Lycium Barbarum in a rat depression model, Collegium Internationale Neuro-Psychopharmacologicum (CINP) 2010 World Congress. 2010, P-09.

Zhang E., Chang R.C.C. and So K.F., Elucidating beneficial effects of Wolfberry (Lycium barbarum) in experimental depression, Society for Neuroscience 2009. Program No. 549.13: Poster No. X7.

Researcher : Zhang G

List of Research Outputs

Tsang C.M., Zhang G., Seto E., Takada K., Deng W., Yip Y.L., Man C.W.Y., Hau P.M., Chen H., Cao Y., Lo K.W., Middeldorp J.M., Cheung A. and Tsao G.S.W., Epstein-Barr virus infection in immortalized nasopharyngeal epithelial cells: Regulation of infection and phenotypic characterization. , International Journal of Cancer. 2010, 127: 1570-1583.

Tsang C.M., Zhang G., Seto E., Takada K., Deng W., Yip Y.L., Man C.W.Y., Hau P.M., Cao Y., Lo K.W. and Middeldorp J.M., Epstein-Barr virus infection in immortalized nasopharyngeal epithelial cells: Regulation of infection and phenotypic characterization, Int. J. Cancer. 2010, 127: 1570-83.

Tsao G.S.W., Tsang C.M., Zhang G., Deng W., Hau P.M., Man C.W.Y., Kenzo T., Chen H., Yip Y.L., Lo K.W., Cao Y. and Cheung A., Epstein-Barr virus infection confer stress-resistant property in immortalized nasopharyngeal epithelial cells., Proceedings of American Association of Cancer Research. 2010.

Researcher : Zhang G

List of Research Outputs

Researcher : Zhang Q

List of Research Outputs

Chang R.C.C., Zhang Q., Hung H.L., Cheung Y.T., Ho Y.S., Lai S.W. and Wuwongse S., Pathogenesis of Alzheimer's Disease, 5th International Symposium on Healthy Aging. 2010, Page 19.

Cheung Y.T., Zhang Q., Hung H.L., Lai S.W., Yu M.S., So K.F. and Chang R.C.C., Investigating the temporal transition of autophagy and apoptosis in neurons stressed by low molecular weight beta-amyloid peptide toxicity, 11th International Geneva/Springfield Symposium on Advances in Alzheimer Therapy, March 24-27, 2010 Geneva. 2010, 42.

Researcher : Zhang W

List of Research Outputs

Yuan Q., Hu B., Wu Y., Chu T.H., Su H., Zhang W., So K.F., Lin Z. and Wu W., Induction of c-Jun phosphorylation in spinal motoneurons in neonatal and adult rats following axonal injury, Brain Research. 2010, 1320: 7-15.

Researcher : Zhou Y

List of Research Outputs

Chiu K., Zhou Y., Yeung S.C., Lok C.K.M., Chan O.O.C., Chang R.C.C., So K.F. and Chiu J., Up-regulation of crystallins is involved in the neuroprotective effect of wolfberry on survival of retinal ganglion cells in rat ocular hypertension model, Journal of Cellular Biochemistry. 2010, 110: 311-320.

-- End of Listing --