University of TorontoFaculty of Medicine

Department of Laboratory Medicine and Pathobiology

“Better models for better drugs!”

First International Annual Conference sponsored by CIHR

Models of Human DiseasesDate: June 29th, 2010Time: 8:30 am-7 pm

Location: Medical Sciences Building, 1 King’s College Circle, MacLeod Auditorium

Rodin, The Thinker

Organizing teamDr. Lorelei Silverman, co-chair, CIHR grant recipientDr. Rosalind Silverman, co-chair, CIHR grant recipient

Team leadersDr. Ruth Warre, communication, newsletterDr. Hamid Raziee, poster coordinator/database coordinatorHassan Bilal, treasurerGazhal Fazli, fundraising Nada Hussain, secretary

Judges:Dr. Mark Gertner, Dr. Peter Sabatini (online), Dr. Guangpei Hou, Dr. AbbasKarbasian (online), Dr. Antonio Rocca, Dr. Lloyd Berger

Volunteers:Morisson Steel, Ehsan Movasaghi, Nardeen Kodous, Anastasya Sivkova, Swati Agnihotri, Mary Yang, Lisa Tran, Isabella Au, Karen Britto, Ashley Ross, Josh Lopes, Lucy Duan, Mark Wan, David Wang, Sameena Vadivelu, Dhruva Thaker, Ami Patel, Chenthila Nagamuthu, Mengxi Dong, Ayesha Siddiqua, Marzena Serwin,

Canadian Institute of Health Research, Genetics Institute of Genetics for awarding us a Meetings, Planning, and Dissemination grantDr. Milton Charlton and Dr. Michelle Bendek, our supervisorsDr. Catharine Whiteside, Dr. Richard Hegele, and Dr. Avrum Gotlieb for their supportDr. Roger Lew, Dr. Ronald Pearlman, and Dr. Andrew WildeAll the outstanding speakers of this conferernceDr. Szczepan Baran and the Vterinary Bioscience Institute for hosting posters Cedarlane for sponsoring our website www.nabmc.infoStudy Advantage for IT and database consultationAbcam for sponsoring the best posters awardsKent Scinetific, Charles River, Fermentas, Roche, Ultident for sponsoring loot bagsUniversity staff for their advice, suggestions, or help during conference preparation San Diego Instruments, Mandel, and Charles River for sponsoring seminar seriesALN magazine, Elsevier, ScientificWorld Journal, and Frontiers in Neuroscience Journal for future publications of abstracts Falk and Falk attorneys for consultation of US affiliations

Many thanks to the institutions, companies and individuals who made the 1st International Annual Conference on Models of Diseases possible due to their generous donations and support:

Roche Fermentas Ultident

PROGRAM8:30 am Registration, Refreshments, Exhibitor displays, Poster set-up9:00 am Dr. Catharine Whiteside, Dean of the Faculty of Medicine, U of Toronto, Welcome message

Dr. Rosalind Silverman and Dr. Lorelei Silverman, University of Toronto, Introduction9:15 am Dr. Lee Adamson -Keynote speaker, Director, Mouse Physiology Core, Centre for Modeling

Human Disease; Principal Investigator, Samuel Lunenfeld Research Institute of Mount Sinai Hospital; Professor, Obstetrics and Gynaecology, University of Toronto.A decade of ENU mutagenesis at the Centre for Modeling Human Disease: Successes and lessons learned

10:00 am Dr. Michelle Bendek, Professor Laboratory Medicine and Pathobiology, U of TorontoUsing a mouse model to study inflammation, fibrosis and calcification of atherosclerosis

10:30 am Dr. Szcezepan Baran, President and COO, Veterinary Bioscience Institute, USARodent laparoscopy refinement for rodent model development of renal, testicular and hepatic laparoscopic implantation of neoplastic cells (dedicated to the memory of Ms. Evelyn Lazar)

11:00 am Coffee break, Refreshments, Exhibitor displays11:15 am Non-Rodent Models of Diseases

Dr. Milton Charlton, Professor, Department of Physiology, University of Toronto, TorontoSquid, Frog, Crayfish, and Drosophila models in Neuroscience

11:45 am Dr. Zhong-Ping Feng, Associate Professor, Department of Physiology, University of Toronto, Lymnaea stagnalis, a multitalented model in integrative neurophysiology

12:00 am Dr. Thomas Koch, Adjunct Professor, Department of Biomedical Sciences, Ontario Veterinary College, University of GuelphEquine umbilical cord blood stem cell and tissue engineering based therapies using the horse as a pre-clinical animal model of orthopedic problems

12:15 pm Lunch, Exhibitor displays/ Poster viewing and judging1:15 pm Dr. Richard Hegele, Chair Department of Laboratory Medicine and Pathobiology, University

of Toronto- Afternoon session opening message1:20 pm Dr. John Wallace, Director, Farncombe Family Digestive Health Research Institute,

McMaster University, Hamilton, Canada Studying human GI inflammation and ulceration using rodent model

1:50 pm Dr. Jeffrey Henderson, Associate Professor, Leslie Dan Faculty of Pharmacy, U of Toronto, Director, Murine Imaging and Histology FacilityDevelopment of interactive surgical and multimodal atlases of the mouse CNS: Toward Integrative Neuroanatomic Measures

2:20 pm Dr. Jack Uetrecht, Professor, Leslie Dan Faculty of Pharmacy, U. of TorontoAnimal models to understand and ultimately prevent idiosyncratic drug reactions

2:50 pm Dr. David Rollo, Professor, McMaster University, Hamilton, CanadaAging and development of successful dietary interventions: Lessons from transgenic growth hormone mice that express a progeroid syndrome of accelerated aging

3:20 pm Coffee break, Refreshments, Exhibitor displays3:35 pm Dr. Adam Karpf, Roswell Park Cancer Institute, Department of Pharmacology and

Therapeutics, Buffalo, USADNA methylation in a murine prostate cancer model

4:05 pm Dr. Levon Khachigian, Director, UNSW Centre for Vascular Research, University of New South Wales, Sydney, AustraliaImmediate-early genes as master regulators in a wide range of vascular disorders

5:00 pm Non-Rodent Models of DiseasesDr. Joseph Culotti, Principal Investigator, Samuel Lunenfeld Research Institute, TorontoC. elegans as a model for gene discovery in the development and function of the nervous system

5:15 pm Dr. Ronald Pearlman, University Professor Emeritus and Senior Scholar, Department ofBiology. York University, TorontoThe Ciliate Protozoan Tetrahymena thermophila as an important animal model organism

5:30 pm Dr. Corey Nislow, Assistant Professor, Banting and Best Department of Medical Research, TorontoGene-dose assays for drug discovery in yeast and man

5:45 pm Dr. Maurice Ringuette, Professor, Cell and Systems Biology Department, U. of TorontoThe use of multiple model organisms to reveal the complex structural and regulatory contributions of an extracellular matrix protein during normal and pathological development

6:00 pm Dr. Joffre Mercier, Professor, Department of Biological Sciences, Brock University, Associate Dean, Faculty of Math & Science

Drosophila as a model system for studying neuropeptides and endocrine regulation6:15 pm Closing remarks and gift certificate draw6:30 pm Awards reception7:15 pm Dinner with the speakers (by invitation only).5

Falk and Falk attorneysImmigration Law

Welcome to the First International Annual Conference on Models of Human Diseases! This initiative springs from our journey through the biomedical field from academia to biotech, to consulting and clinical research and back to academia and our belief that global scientific exchange can accelerate drug development. Once the CIHR awarded us a grant to organize this conference we had 30 days to turn it into reality. Here is the recipe: an amazing team of volunteers with the right proportion of dreamers and doers, enthusiasts and realists. Add deans of universities and high school students, supervisors and graduate and undergraduate students from around the globe, administrative secretaries and foreign trained researchers, clinicians, biotech and pharma scientist, policy makers, postoctoral fellows, life science companies, lawyers, and advocacy groups.We wish you a stimulating day of science!

Dr. Lorelei Silverman Dr. Rosalind Silverman

Dr. A. Joffre Mercier

Drosophila as a model system for studying neuropeptides and endocrine regulationNeuropeptides are oligopeptides that can act as neurotransmitters, hormones and modulators. Approximately fifty neuropeptides have been identified in the human central nervous system, and many hundred have been identified in vertebrate and invertebrate species. Although it is known that levels of neuropeptides are altered in diseases such as Huntington’s Disease and Alzheimer’s Disease, a thorough understanding of clinical conditions requires more complete understanding of how neuropeptides mediate physiological responses and modulate behaviour through their actions at systemic, cellular and sub-cellular levels. Drosophila melanogaster provides numerous advantages as a model system for such studies. Every muscle fiber in the larvae has been identified, and the innervation of each fiber is known, making it possible to study synaptic interactions between identified cells using electrophysiologicaland optical methods. Some of these synapses release neuropeptides, and some are modulated by neuropeptides. Since the Drosophila genome has been cloned and sequenced, mutant and transgenic fly lines have become available for studying the roles of G-protein coupled receptors and intracellular messengers in mediating peptide-induced effects on chemical synapses, muscle contraction and behaviour.

Professor, Department of Biological Sciences,Brock University, Associate Dean, Faculty of Math & Science

The use of multiple model organisms to reveal the complex structural and regulatory contributions of an extracellular matrix protein during normal and pathological developmentShortly after fertilization, multicellular organisms synthesize and secrete a complex mixture of structurally and functionally diverse extracellular matrix (ECM) molecules. In addition to acting as scaffolding for the organization and stability of tissues, ECM molecules regulate cell survival and behavior. We have been using a variety of model organisms to decipher the precise morphogenetic contributions of SPARC (Secreted Protein, Acidic, Rich in Cysteine) during normal and pathological development. SPARC is a small, collagen- and calcium-binding “matricellular” glycoprotein that is expressed at high levels in tissue undergoing morphogenesis, remodeling or wound repair. SPARC has also attracted considerable interest due to its altered expression during progression of diverse diseases (e.g. fibrosis and cancer). Our studies with the cnidarian starlet sea anemone Nematostella vectensis indicate that the collagen-binding domain of SPARC is conserved throughout metazoan evolution. We have used the African clawed frog Xenopus laevis to demonstrate a critical requirement for SPARC during post-gastrula development. Specifically, SPARC, directly or indirectly, promotes cell-cell adhesion which is required for the maintenance of tissue integrity during organogenesis. Using the powerful molecular and genetic tools available for the fruit fly Drosophila melanogaster, our data indicate that SPARC is expressed at high levels in the fat body, an organ compared functionally to vertebrate adipose tissue and liver that serves as a major organ for energy storage and metabolism. Our data indicate that the fat body is absent during larval development in Sparc-null flies. SPARC has been suggested to have anti-tumour effects on ovarian cancer progression, in part due to its demonstrated ability to inhibit cell proliferation and migration. We have recently shown using a chick chorioallantoic membrane assay that a mimetic peptide corresponding to the most evolutionary conserved domain of SPARC prevents endothelial cell branching angiogenesis. We plan to use this in vivo assay in combination with a mouse syngeneic model of ovarian cancer to better understand the anti-tumor activity of SPARC during ovarian cancer progression and metastasis. Each of the above models has offered unique insight into this ECM glycoprotein with complex spatiotemporal distributions during embryogenesis and whose expression is altered in several disease states.

Dr. Maurice RinguetteProfessor, Cell and Systems Biology Department, University of Toronto, Toronto

Greetings for The 1st International Annual Conference of Models of Human DiseasesOn behalf of the Faculty of Medicine, I am pleased to enthusiastically congratulate the organizers of the First International Annual Conference of Models of Human Disease on this great achievement. To Drs. Lorelei and Rosalind Silverman and their faculty supervisors Professors

Milton Charlton and Michelle Bendeck, many thanks for your creative development of this outstanding project. Sponsored by the CIHR and many other contributors, this conference has attracted investigators and students from across the globe who share significant interest in animal models of human disease.

In the era of personalized medicine, we look to the translation of molecular and cellular mechanisms of disease into innovative bedside applications. The necessary intermediate step is the study of animal models in which the manipulation of genes, proteins, cells and systems to fully understand how human diseases are generated. This approach enables the testing of new diagnostic and therapeutic interventions that provide important new directions in health care. May I wish all the participants success in networking and establishing new opportunities for collaboration during this conference. I hope you also enjoy Toronto and our wonderful University of Toronto campus.Dr. Catharine Whiteside, MD, PhD, FRCPC, FCAHS

Dean, Faculty of Medicine, Profesor of Medicine University of Toronto

respectively, as a Research Associate at the University of Toronto in the Department of Physiology (Supervisor: Dr. Milton Charlton) and as a Post-doctoral fellow, Department of Laboratory Medicine and Pathobiology(Supervisor: Dr. Michelle Bendeck). Earlier this year, Lorelei and Rosalind organized what has become a popular and highly successful seminar series on Animal Models of Human Disease at the University of Toronto, and for this International Conference the scope has been extended to also include cellular models.

The Canadian Institutes of Health Research, the major federalfunding body of biomedical research in Canada, has providedfinancial support for this International Conference in the form of a

competitive award, and the engagement of additional sponsors is atestament to the broad relevance and potential impact of this areaof research. The ability for interested individuals from around theworld to engage in information and knowledge exchange in models ofhuman disease is timely. People at all levels of expertise andexperience stand to benefit from participating in the discourse andexploring new opportunities to form or strengthen researchcollaborations.Sincerest best wishes for an exciting, stimulating and successful meeting.

Greetings for 1stInternational Conference of Models of Human Diseases

On behalf of the Department of Laboratory Medicine and Pathobiology of the University of Toronto, I would like to extend a warm welcome to all attendees of the First International Annual Conference of Models of Human Diseases. The origins of this International Conference can be attributed to the tireless efforts of two sisters, Drs. Lorelei and Rosalind Silverman, who work,

Richard G. Hegele, MD, FRCPC, PhDProfessor and Chair

Department of Laboratory Medicine and PathobiologyUniversity of Toronto

Gene-dose assays for drug discovery in yeast and manMy lab is interested in understanding the interaction of small molecules with their protein targets and target pathways. To accomplish this, we use comprehensive collections of cells in which the gene dosage is systematically altered (decreased or increased). We have utilized the Yeast Knock Out collection (YKO) and combined it with a collection of yeast overexpressing each gene to screen thousands of bioactive small molecules genome-wide, identifying many novel gene-drug interactions. More recently we have expanded the scope of these gene-dose screens to other organisms and genomes. For example, we have successfully screened the human ORFeome, expressed in yeast, with FDA approved compounds and have identified several known and novel interactions. In collaboration with Jason Moffat’s laboratory, we've initiated a large-scale effort to translate these gene-dose screens to mammalian cells using pools of cells infected with lentiviral-encoded shRNAs and human OFRs. I will present several compelling drug-target interactions that have been uncovered using a combination of these gene-dose screens as well as provide an overview of our efforts to develop novel microarray and next-generation sequencing technologies to accelerate the tempo of these chemogenomic assays.

Dr. Corey NislowAssistant Professor,Banting and Best Department of Medical Research, University of Toronto

A decade of ENU mutagenesis at the Centre for Modeling Human Disease: Successes and lessons learnedToronto’s Centre for Modeling Human Disease (CMHD) used dominant ENU-mutagenesis to generate new mouse models of disease from 2000-2010. The talk will highlight some of our successes and challenges. We phenotyped 9,600 first generation mice using broad-based, high-throughput screens. Of 2,218 outliers (2 SD), 293 were selected heritability testing. 127 were heritable. 52 of the most interesting ones were mapped to chromosome location. So far, 26 point mutations are identified and 24 mutants are listed in the International Mouse Strain Resource. Young adult mice were screened for heart (15 heritable, 6 mapped, 2 cloned), blood (39 heritable, 13 mapped, 3 cloned), bone density (17 heritable, 5 mapped, 2 cloned), neurobehavior/ appearance (44 heritable, 23 mapped, 17 cloned), kidney (6 heritable, 2 mapped, 2 cloned), and other dysfunctions (5 heritable, 3 mapped, 0 cloned). 46 heritable lines have been distributed to 44 labs world-wide. CMHD’s cost-recovery phenotyping (www.cmhd.ca) has been used by 170 investigators across Canada and USA.

Dr. Lee AdamsonDirector, Mouse Physiology Core, Centre for Modeling Human Disease; Principal Investigator, Samuel Lunenfeld Research Institute of Mount Sinai Hospital; Professor, Obstetrics and Gynaecology, U. of Toronto

Dr. Ronald PearlmanUniversity Professor Emeritus and Senior Scholar, Department of Biology, York University, Toronto

The Ciliate Protozoan Tetrahymena thermophila as an important animal model organismThe ciliate protozoan Tetrahymena thermophila belongs to the Alveolates, a major evolutionary branch of eukaryotic protists. T. thermophila is a microbial model organism for a wide variety of research disciplines. In addition to its proven importance as a model system for discovering fundamental principles of eukaryotic biology, it is the most experimentally amenable member of the Alveolates and of the evolutionarily diverse ciliate species that colonize worldwide niches as free-living organisms, parasites, and mutualisticsymbionts. The ultrastructure, cell physiology, development, biochemistry, genetics, and molecular biology of Tetrahymena havebeen extensively investigated and display a degree of structural and functionalcomplexity comparable to that of human and other metazoan cells. Recentgenome sequencing projects have confirmed that these extensive andcomplex genomes conserve a rich set of ancestral eukaryotic functions. Tetrahymena has allowed major discoveries in biology such as catalytic RNA and rybozymes (Nobel prize), variant nuclear genetic codes, telomeres and telomerase (Nobel prize), histone acetyl transferase as a transcription factor/co-activator, and recently discovered epigenetic phenomena acting at DNA (programmed somatic DNA rearrangement), RNA (e.g. RNA interference), and protein levels. Unique among unicellular eukaryotes, ciliates separate germinal and somatic lines, in the form of nuclei. Somatic development involves programmed rearrangements of the entire germline genome at each sexual generation and provides an excellent experimental model to study somatic DNA rearrangements similar to those that generate antibody diversity and malignant states in vertebrates. An impressive array of novel molecular genetic technologies place Tetrahymena at the forefront of experimental, in vivo functional genomics research. These tools include but are not limited to: facile maintenance of lethal mutations and essential gene knockouts in the silent germline of heterokaryons; high frequency DNA transformation with high-copy replicative vectors or by precise homologous recombination; easily manipulated inducible promoters allowing effective regulation of gene expression; gene and protein tagging for protein localization and protein/protein interaction studies; use of double stranded RNA for gene regulation; ribosomal antisense repression; and cloning by complementation. The richness of its genome makes this a useful model for addressing important questions including those with applications related to human health that cannot be investigated in other unicellular eukaryotic microbial systems. I will present an overview of features of Tetrahymena making it a powerful animal model organism, focusing on epigenetic mechanisms involving RNAi and heterochromatin in irreversible gene silencing.

Dr. Michelle BendeckProfessor,Department of Laboratory Medicine and Pathobiology,University of Toronto

The role of the extracellular matrix in atherosclerotic inflammation, fibrosis and calcification Interaction between cells and the extracellular matrix provide structural support in the blood vessel, and allow the opportunity for signaling and mechanotransduction. Collagens are abundant in the atherosclerotic plaque, and these molecules play both protective and harmful roles in atherogenesis. My lab is studying the discoidindomain receptor 1 (DDR1), a collagen-binding receptor tyrosine kinase. We have recently described a critical role for DDR1 in atherosclerotic plaque development, regulating inflammation, fibrosis, and calcification in a mouse model of the disease. I will discuss our ongoing work to elucidate the cellular, molecular and signaling mechanisms. Taken together , our studies suggest that inhibition of DDR1 may be an important therapeutic target to limit inflammation, calcification and plaque growth, and to promote stability.

Molecular mechanisms underlying cell and axon migrations in C. elegans

Dr. Joseph CulottiProfessor, Department of Molecular and Medical Genetics, University of Toronto, Senior Investigator Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Canada

A novel TGF-beta and a G-protein coupled receptor are involved in UNC-6/netrin mediated axon guidance and cell migration in C. elegans. Jasmine Plummer and Joe Culotti.The netrin axon guidance and cell migration cue was first discovered as a predicted product of the unc-6 gene in C. elegans, where it was shown to mediate both attractive and repulsive responses depending on the repertoire of UNC-5/RCM and UNC-40/DCC receptors expressed by these cells. By ectopically expressing UNC-5 in specific sensory neurons that already expressed UNC-40, we made their axons switch from an attractive response to a repulsive response to UNC-6. We showed the new ‘switched’ UNC-6-dependent guidance response was sensitized to the dose of unc-6(+) and used the ‘switched’ strain to carry out a genetic screen for suppressors of the ‘switched’ phenotype to identify additional genes that act in the UNC-6 – UNC-5 signaling pathway. In this screen we recovered weak alleles of unc-6 and unc-40, showing the screen worked as hoped. We also discovered unc-129 -mutations of cause motor axon guidance defects resulting in uncoordinated locomotion. We found that unc-129 encodes a novel TGF-beta that acts through a non-classical signaling mechanism to regulate sensitivity of growth cones to UNC-6. We also recently discovered a mutation that suppresses the ‘switched’ phenotype, which on its own does not normally cause motor axon guidance defects suggesting it has a redundant function with another guidance gene. This mutation identifies the seu-2 gene which we have found encodes a novel G-protein coupled receptor (GPCR) involved in both attractive and repulsive responses to UNC-6. Finally, we have found that this GPCR functions in neurons whose axon guidance is affected by seu-2 mutations. Since GPCRs are targets of most pharmaceuticals of clinical relevance, we hope that understanding how this GPCR functions will lead to improved pharmacological interventions for human disorders that are sensitive to increased or decreased netrin-mediated signaling.

Dr. Levon KhachigianDirector, UNSW Centre for Vascular Research, University of New South Wales, Sydney, Australia

Immediate-early genes as master regulators in a wide range of vascular disordersCardiovascular disease and cancer remain the most prevalent causes of morbidity and mortality. The pathogenesis of these and a myriad of related diseases is underpinned by molecular and cellular changes in our blood vessels. Professor Khachigian’s research is uncovering key networks of transcriptional control and induciblegene-regulatory circuits that lead to vascular disease. The group is also developing new experimental drugs that have the potential to treat a diverse range of health problems, from cancer and inflammation through to eye and heart disease. research programhas two major objectives: 1. To better understand how harmful genes are controlled in vascular cells. This arm investigates signaling and transcriptional mechanisms of pro-inflammatory cytokine-dependent gene expression, post-translational mechanisms that modify protein behavior, proteinase control, the isolation and characterization of new genes induced or repressed by vascular cell injury, and the molecular control of vascular cell migration andproliferation. The group has considerable expertise in animal models of neointima formation, angiogenesis, tumor growth, myocardial ischemia, and inflammation. 2. To develop new vascular therapeutic agents. The lab is harnessing the outcomes of its fundamental research by pioneering the development of novel “anti-gene-” and “gene-therapeutic” strategies targeting key regulatory genes in a myriad of vascular disorders. This involves strategic collaborations with a range of clinical specialists, academics and drug development consultants.

Rat laparoscopic biopsies lead to decreased postoperative painThe refinement of current surgical techniques represents a key opportunity to improve the welfare of laboratory rodents, while meeting legal and ethical obligations. Minimally invasive surgery such as laparoscopy is considered the gold standard for many human abdominal procedures. Laparoscopy results in decreased pain, decreased tissue trauma and more rapid post surgical recovery. Compared to laparotomy, laparoscopy preserves immune function when equivalent procedures are performed. Many of these benefits have been demonstrated in rodents with the exception of pain management. A pilot study was conducted using three groups; rats that had undergone laparoscopic liver biopsy via laparoscopy, rats that had undergone liver biopsy via laparotomy, and rats exposed to inhalant anesthesia alone. Preliminary data, which included quantitative behavior analysis of assessing post-operative pain, demonstrated that laparoscopic procedures lead to less post surgical pain than laparotomy. Additional studies are required, but this initial data suggest that laparoscopy in rodents might represent a significant surgical refinement for the reduction of post-operative pain.

Dr. Szczepan BaranPresident and Chief Operating Officer, Veterinary Bioscience Institute in Harleysville, Pennsylvania

Dr. Milton CharltonProfessor,Department of Physiology,University of Toronto

Squid, Frog, Crayfish, and Drosophila models in NeuroscienceBasic neuronal mechanisms are highly conserved and all discoveries of these mechanisms made in Invertebrates have been confirmed later in mammals. The large presynaptic terminal of the squid giant synapse allows voltage clamping of calcium currents and injection of chemicals and proteins into the transmitter release sites. Basic concepts of calcium signaling were developed with this preparation and these ideas were used in stroke research. The quantal nature of transmitter release was discovered in the frog neuromuscular junction (NMJ). The regular array of active zones where exocytosis occurs was exploited to examine the exclusive localization of calcium channels. Invertebrate NMJs have been the source of several seminal discoveries in Neuroscience such as the mechanism of presynaptic inhibition. The crayfish NMJ has a small number of identified presynaptic axons of large enough diameter to permit intracellular recording and injection. Moreover, there is a huge degree of presynaptic differentiation; synapses of different motorneurons differ wildly in presynaptic release properties. Therefore, one can ask how synapses become different as a natural growth process rather than during pesky learning paradigms. The Drosophila NMJ also has few motor neurons innervating each muscle fibre but they are much thinner than in crayfish. However, Drosophila has the advantage of a known genome and the availability of many mutants. Several mutations the model human diseases are available. For instance there is a Drosophila model of Niemann-Pick disease in which there is abnormal membrane cholesterol distribution. We have studied the importance of membrane and synaptic vesicle cholesterol by exploiting a Drosophiladynamin mutant which allows access to the vesicle lumen.

DNA methylation in murine prostate cancer DNA methylation in mammals is a covalent modification of cytosine residues residing within CpG dinucleotides, and is catalyzed by DNMT enzymes post DNA replication. DNA methylation plays a critical role in mammalian development, genomic imprinting, transcriptional regulation, X-chromosome inactivation, and genomic stability. Notably, abnormalities in DNA methylation are ubiquitous in human cancer. These changes include both DNA hypermethylation and hypomethylation, which occur at distinct regions of the genome. While substantial correlative data exist linking DNA methylationchanges to human cancer, in vivo model systems will be required to elucidate the functional role of these changes in tumor development and progression. Our laboratory is conducting studies that utilize the TRansgenic Adenocarcinomaof Mouse Prostate (TRAMP) model to define the nature and contribution of DNA methylation changes to prostate cancer. We have observed that DNA methylation abnormalities occur in a tumor-stage specific manner, and correlate with gene expression changes. Furthermore, we have shown that reduced expression of the Dnmt1 enzyme in TRAMP significantly alters tumor development. Most prominent among the changes observed is a striking reduction in tumor metastases. In summary, murinemodels have proven useful for evaluating the functional contribution of DNA methylation to prostate cancer.

Dr. Adam KarpfAssociate Professor, Roswell Park Cancer Institute, Department of Pharmacology and Therapeutics Buffalo, NY

Dr. David RolloProfessor, Department of Biology, McMaster University

Diverse pathologies including cardiovascular disease, stroke, diabetes, obesity, neurodegenerative conditions, cancer and inflammation are associated with elevated free radical processes. Most of these are age-related so slowing aging could ameliorate all of these conditions simultaneously. Dietary supplements composed of one or a few ingredients have had little success. We formulated a complex dietary supplement targeting five key processes of aging and tested it on normal mice and transgenic mice expressing accelerated aging. The supplement prevented age-related cognitive declines, forestalled bradykinesis (declining physical activity), upregulated neurotransmitters, ameliorated radiation-induced DNA damage and apoptosis, reversed declines in mitochondrial activity, and increased longevity. Remarkably, the supplement reduced mitochondrial protein carbonyls per unit complex III activity by ~ 50%. Reduction of free radical generation by mitochondria (a cleaner burn) is considered thecritical mechanism extending longevities in dietary restricted animals and birds and is considered the “silver bullet” for aging interventions. Results provide proof of principle that cocktails of dietary supplements may indeed extend youthful function into older ages.

Aging and Development of Successful Dietary Interventions: Lessons from Transgenic Growth Hormone Mice That Express a Progeroid Syndrome of Accelerated Aging.

Dr. Zhong-Ping FengAssociate Professor,Department of Physiology, University of Toronto

Lymnaea stagnalis, a multitalented model in integrative neurophysiologyThe freshwater pond snail, Lymnaea stagnalis (L. stagnalis) has served as a model for a wide spectrum of fundamental studies in molecular, cellular, and behavioral neurobiology. One of the major advantages of L. stagnalis is its simple central nervous system (CNS). The snail central neurons are large and many of them are individually identifiable, thus allowing electrophysiological dissection of neuronal networks in vivo. Studies using L. stagnalis as a model have made significant contributions in our understanding of the biophysical propertiesof neurons, synaptic transmission, and neural networks involved in feeding, respiration, defensive withdrawal, locomotion, gravity orientation, reproduction, and learning and memory. Individual neurons that are identified as parts of defined behavioural circuits in adult animal can be isolated and maintained in cell culture, where synaptic connections reliably re-establish. This property of the snail serves as an excellent tool to study the specificity of synapse remodelling between adult neurons. We have taken advantages of the CNS of L. stagnalis, in combination with acute targeted-gene silencing approaches, to identify novel cellular and molecular mechanisms in neuronal regeneration, synapse formation, memory formation, and hypoxic stress. Our recent large-scale transcriptome sequencing and proteomics analyses of the L. stagnalis CNS have identified a number of molecules that are orthologues to the genes related to neurological disorders. In light of these new findings, the snail model can be further used in functional genetics studies relatedto neurodegenerative and neurodevelopmental diseases.

Dr. Thomas KochAdjunct Professor, Department of Biomedical Sciences, Ontario Veterinary College, U. of Guelph, Research Associate OrthopaedicResearch Laboratory, Aarhus University Hospital, Denmark

Equine umbilical cord blood stem cell and tissue engineering based therapies using the horse as a pre-clinical animal model of orthopedic problemsStem cells and tissue engineering have received considerable attention due to their potential therapeutic use in the past few decades although none of the commercially approved products as of late 2002 had made a profit despite a total industry investment in research and development exceeding US dollar 4.5 billion. The causes of the inadequate return of these investments are undoubtlymultifacorial, but there is an emerging recognition in the biomedical field of the need for intermediate animal models, which can bridge the proof-of-principle studies in small laboratory animals and human clinical trials. The animal models of experimental induced arthroses currently used to assess biological safety and efficacy appear fundamentally flawed. The reason being that the joint and cartilage environment of a spontaneously occurring lesion of possible long-lasting duration may very well be significantly different than the environment of limited acute injuries induced in a otherwise healthy joint. If this notion is accepted, then the cellular tissue response of both implanted and native cells and tissues may also behave significantly differently. A number of domestic animals could serve as models of spontaneous joint lesions. Specifically, comparative studies have shown that the articular cartilage thickness of horses most closely resembles that of human articular cartilage. Both induced arthroses and spontaneous cartilage defects can be studied in the Horse. Spontaneous joint problems are a common problem in horses and the familiarity of horses to being handled makes them an ideal species to evaluate selected rehabilitation programs. The significance of weight-bearing/loading of joint immediately post-operatively is another important parameter that can be assessed using the horse as an animal model. This is of particular interest in human medicine where so-called fast-track surgery programs are being increasingly implemented to decrease co-morbidities related to bed rest and inactivity post-operatively. The recent isolation of multipotentmesenchymal stromal cells (MSCs) from equine umbilical cord blood makes for a very interesting research opportunity evaluating these cells utility in cartilage repair in the horse.

Dr. Jack UetrechtProfessor of Pharmacy and Medicine, CRC Chair in Adverse Drug Reactions,Leslie Dan Faculty of Pharmacy, University of Toronto

Animal models to understand and ultimately prevent idiosyncratic drug reactionsIdiosyncratic drug reactions (IDRs) are a major source of patient morbidity and mortality. They also significantly increase the risk of drug development because they are not discovered until very late in development and often after a drug has been marketed. There is little known with certainty about their mechanisms and without such understanding we are unlikely to make progress in predicting and preventing IDRs. Their unpredictability make prospective human mechanistic studies impossible, and although animals can also have IDRs they are also idiosyncratic in animals. Therefore, there are almost no valid animal models of IDRs. We have developed one animal model in which nevirapine causes a skin rash in rats that is very similar to the rash that it causes in humans. This rash is caused by a metabolite of nevirapine and it is immune-mediated. In particular, substitution of deuterium for hydrogen on the molecule at the site of reactive metabolite formation decreases the incidence of rash and sensitivity to nevirapine can be transferred to naïve animals with spleen cells. Depletion of CD4+ T cells is protective but depletion of CD8+ T cells appears to make the rash worse. This model is very helpful in studies of how small molecules can lead to an immune response. However, different drugs cause IDRs with different characteristics and this presumably reflects mechanistic differences. Therefore, we need several animal models to determine to what degree the mechanisms of different IDRs differ. We discovered the nevirapine model by accident, but if most IDRs are caused by chemically reactive metabolites and immune-mediated it should be possible to develop new animal models by increasing the production of reactive metabolites, stimulating the immune system and inhibiting immune tolerance. However, despite several years of work, these strategies have not been successful. Furthermore, even though we know that the nevirapine-induced skin rash is immune-mediated, factors that would be expected to increase its incidence/severity have not had the expected effects. Therefore, our inability to develop animal models by trying to manipulate the immune response to not mean that other IDRs are not immune-mediated. It does indicate that we have a limited understanding of the immune system.

Dr. Jeffrey HendersonAssociate Professor,Leslie Dan Faculty of Pharmacy, University of TorontoDirector, Murine Imaging and Histology (MIH) Facility

Development of Interactive Surgical and Multimodal Atlases of the mouse CNS:Toward Integrative Neuroanatomic MeasuresOver the past quarter century genetically modified mice have emerged as major experimental models to probe fundamental aspects of the mammalian CNS; both during development and following injury. Themorphologic effects resulting from a given gene targeting or CNS injury event frequently manifest itself at multiple neuroanatomic loci. Accurate integrated interpretation and/or quantitative assessment of such features are often difficult or impossible to determine using standard histologicmeasures. In order to enhance investigators ability to more robustly analyze the effects of these and other interventions, we have developed two open source tools toexamine the comparative neuroanatomy of the mouse CNS. In the first, we examined population-based variability of the CNS in 129S1/SvImJ,C57Bl/6J inbred and CD1 outbred strains of mice. Determining the limits of such natural variability represents a requisite precondition to provide confidence limits to any morphologic changes seen following intervention. In the second, we analyzed the brain and skull of numerous murine strains to develop a new more robust and accurate stereotactic coordinate system providing improved stereotactic accuracy. We have utilized these tools to develop the first detailed three dimensional understanding of how EphB-type receptors regulate guidance decisions required for formation of the anterior commissure (AC) in the murineforebrain. Using this system we demonstrate for the first time that loss of EphA4 results in significant displacement of the AC pars anterior into regions which developmentally express isoforms of EphA4 repulsive cues. We also demonstrate that EphB2 and EphA4 regulate distinct aspects of axon guidance within the pars posterior of the AC, and that these receptors act synergistically to prevent axons within the AC par anterior from mis-projecting caudally.

Studying Human GI Inflammation and Ulceration Using Rodent Models

Inflammation plays in important role in the pathogenesis of several common diseases of the gastrointestinal (GI) tract, including inflammatory bowel disease, celiac disease, peptic ulcer and the gastroenteropathiesassociated with the use of nonsteroidal anti-inflammatory drugs (NSAIDs). Over the past few decades, a great deal has been learned about the pathogenesis of these and other GI disorders through the use of animal models. For example, several rodent models of colitis have been developed which have been exploited for testing of novel therapies, but also for investigating potential mechanisms of tissue injury and repair. Similar, models of NSAID-induced GI injury have been widely employed to better understand these conditions, and to develop safer anti-inflammatory drugs. These models have also been used to study endogenous mediators of resolution of inflammation (i.e., anti-inflammatory signals), and of healing.

Dr. John L. WallaceDirector, Farncombe Family Digestive Health Research Institute, McMaster University