Models of Human Diseases Conference 2010 oral presentations abstracts
University of Toronto Faculty of Medicine Department of Laboratory Medicine and Pathobiology “Better models for better drugs!” First International Annual Conference sponsored by CIHR Models of Human DiseasesOrganizing team Date: June 29th, 2010Dr. Lorelei Silverman, co-chair, CIHR grant recipientDr. Rosalind Silverman, co-chair, CIHR grant recipient Time: 8:30 am-7 pmTeam leaders Location: Medical Sciences Building, 1 King’s CollegeDr. Ruth Warre, communication, newsletterDr. Hamid Raziee, poster coordinator/database coordinator Circle, MacLeod AuditoriumHassan Bilal, treasurerGazhal Fazli, fundraisingNada Hussain, secretaryJudges:Dr. Mark Gertner, Dr. Peter Sabatini (online), Dr. Guangpei Hou, Dr. AbbasKarbasian (online), Dr. Antonio Rocca, Dr. Lloyd BergerVolunteers: Rodin, The ThinkerMorisson Steel, Ehsan Movasaghi, Nardeen Kodous, Anastasya Sivkova,Swati Agnihotri, Mary Yang, Lisa Tran, Isabella Au, Karen Britto, AshleyRoss, Josh Lopes, Lucy Duan, Mark Wan, David Wang, Sameena Vadivelu,Dhruva Thaker, Ami Patel, Chenthila Nagamuthu, Mengxi Dong, AyeshaSiddiqua, Marzena Serwin,
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 Many thanks to the institutions, companies and individuals who made the Dr. Rosalind Silverman and Dr. Lorelei Silverman, University of Toronto, Introduction 1st International Annual Conference on Models of Diseases possible due to their9:15 am Dr. Lee Adamson -Keynote speaker, Director, Mouse Physiology Core, Centre for Modeling Human Disease; Principal Investigator, Samuel Lunenfeld Research Institute of Mount Sinai generous donations and support: Hospital; Professor, Obstetrics and Gynaecology, University of Toronto. A decade of ENU mutagenesis at the Centre for Modeling Human Disease: Successes and Canadian Institute of Health Research, Genetics Institute of Genetics for awarding us lessons learned10:00 am Dr. Michelle Bendek, Professor Laboratory Medicine and Pathobiology, U of Toronto a Meetings, Planning, and Dissemination grant Using a mouse model to study inflammation, fibrosis and calcification of atherosclerosis Dr. Milton Charlton and Dr. Michelle Bendek, our supervisors10:30 am Dr. Szcezepan Baran, President and COO, Veterinary Bioscience Institute, USA Dr. Catharine Whiteside, Dr. Richard Hegele, and Dr. Avrum Gotlieb for their support Rodent laparoscopy refinement for rodent model development of renal, testicular and Dr. Roger Lew, Dr. Ronald Pearlman, and Dr. Andrew Wilde All the outstanding speakers of this conferernce hepatic laparoscopic implantation of neoplastic cells (dedicated to the memory of Ms. Evelyn Lazar)11:00 am Coffee break, Refreshments, Exhibitor displays Dr. Szczepan Baran and the Vterinary Bioscience Institute for hosting posters11:15 am Non-Rodent Models of Diseases Cedarlane for sponsoring our website www.nabmc.info Dr. Milton Charlton, Professor, Department of Physiology, University of Toronto, Toronto Squid, Frog, Crayfish, and Drosophila models in Neuroscience Study Advantage for IT and database consultation11:45 am Dr. Zhong-Ping Feng, Associate Professor, Department of Physiology, University of Toronto, Abcam for sponsoring the best posters awards Lymnaea stagnalis, a multitalented model in integrative neurophysiology Kent Scinetific, Charles River, Fermentas, Roche, Ultident for sponsoring loot bags12:00 am Dr. Thomas Koch, Adjunct Professor, Department of Biomedical Sciences, Ontario University staff for their advice, suggestions, or help during conference preparation San Diego Instruments, Mandel, and Charles River for sponsoring seminar series Veterinary College, University of Guelph Equine umbilical cord blood stem cell and tissue engineering based therapies using the horse as a pre-clinical animal model of orthopedic problems ALN magazine, Elsevier, ScientificWorld Journal, and Frontiers in Neuroscience12:15 pm Lunch, Exhibitor displays/ Poster viewing and judging Journal for future publications of abstracts Falk and Falk attorneys for consultation of1:15 pm Dr. Richard Hegele, Chair Department of Laboratory Medicine and Pathobiology, University of Toronto- Afternoon session opening message US affiliations1:20 pm Dr. John Wallace, Director, Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, Canada Studying human GI inflammation and ulceration using rodent model1:50 pm Dr. Jeffrey Henderson, Associate Professor, Leslie Dan Faculty of Pharmacy, U of Toronto, Director, Murine Imaging and Histology Facility Development of interactive surgical and multimodal atlases of the mouse CNS: Toward Integrative Neuroanatomic Measures2:20 pm Dr. Jack Uetrecht, Professor, Leslie Dan Faculty of Pharmacy, U. of Toronto Animal models to understand and ultimately prevent idiosyncratic drug reactions2:50 pm Dr. David Rollo, Professor, McMaster University, Hamilton, Canada Aging and development of successful dietary interventions: Lessons from transgenic growth hormone mice that express a progeroid syndrome of accelerated aging3:20 pm Coffee break, Refreshments, Exhibitor displays3:35 pm Dr. Adam Karpf, Roswell Park Cancer Institute, Department of Pharmacology and Therapeutics, Buffalo, USA DNA methylation in a murine prostate cancer model4:05 pm Dr. Levon Khachigian, Director, UNSW Centre for Vascular Research, University of New South Wales, Sydney, Australia Immediate-early genes as master regulators in a wide range of vascular disorders5:00 pm Non-Rodent Models of Diseases Dr. Joseph Culotti, Principal Investigator, Samuel Lunenfeld Research Institute, Toronto C. elegans as a model for gene discovery in the development and function of the nervous system5:15 pm Dr. Ronald Pearlman, University Professor Emeritus and Senior Scholar, Department of Biology. York University, Toronto The Ciliate Protozoan Tetrahymena thermophila as an important animal model organism5:30 pm Dr. Corey Nislow, Assistant Professor, Banting and Best Department of Medical Research, Toronto Gene-dose assays for drug discovery in yeast and man5:45 pm Dr. Maurice Ringuette, Professor, Cell and Systems Biology Department, U. of Toronto The use of multiple model organisms to reveal the complex structural and regulatory contributions of an extracellular matrix protein during normal and pathological development6:00 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 reception Roche Fermentas Ultident7:15 pm Dinner with the speakers (by invitation only).5 Falk and Falk attorneys Immigration Law
Dr. A. Joffre Mercier Professor, Department of Biological Sciences, Brock University, Associate Dean, Faculty of Math & ScienceDrosophila as a model system for studying Dr. Lorelei Silverman Dr. Rosalind Silverman Welcome to the First Internationalneuropeptides and endocrine regulation Annual Conference on Models ofNeuropeptides are oligopeptides that can act as Human Diseases! This initiative springsneurotransmitters, hormones and modulators. Approximately fifty from our journey through theneuropeptides have been identified in the human central nervous biomedical field from academia tosystem, and many hundred have been identified in vertebrate biotech, to consulting and clinicaland invertebrate species. Although it is known that levels of research and back to academia and ourneuropeptides are altered in diseases such as Huntington’s belief that global scientific exchangeDisease and Alzheimer’s Disease, a thorough understanding of can accelerate drug development. Onceclinical conditions requires more complete understanding of how the CIHR awarded us a grant toneuropeptides mediate physiological responses and modulate organize this conference we had 30 daysbehaviour through their actions at systemic, cellular and sub- to turn it into reality. Here is the recipe:cellular levels. Drosophila melanogaster provides numerous an amazing team of volunteers with theadvantages as a model system for such studies. Every muscle right proportion of dreamers and doers,fiber in the larvae has been identified, and the innervation of enthusiasts and realists. Add deans ofeach fiber is known, making it possible to study synaptic universities and high school students,interactions between identified cells using electrophysiological supervisors and graduate andand optical methods. Some of these synapses release undergraduate students from around theneuropeptides, and some are modulated by neuropeptides. globe, administrative secretaries andSince the Drosophila genome has been cloned and sequenced, foreign trained researchers, clinicians,mutant and transgenic fly lines have become available for biotech and pharma scientist, policystudying the roles of G-protein coupled receptors and makers, postoctoral fellows, life scienceintracellular messengers in mediating peptide-induced effects on companies, lawyers, and advocacychemical synapses, muscle contraction and behaviour. groups. We wish you a stimulating day of science!
Greetings for The 1st International Dr. Maurice Ringuette Annual Conference of Models of Professor, Cell and Systems Human Diseases On behalf of the Faculty of Biology Department, Medicine, I am pleased to University of Toronto, enthusiastically congratulate the Toronto organizers of the First International Annual Conference of Models of Human Disease on this great achievement. To Drs. Lorelei and The use of multiple model organisms to reveal the Rosalind Silverman and their faculty supervisors Professors complex structural and regulatory contributions ofMilton Charlton and Michelle Bendeck, many thanks for an extracellular matrix protein during normal andyour creative development of this outstanding project. pathological development Shortly after fertilization, multicellular organisms synthesize and secrete a complex mixtureSponsored by the CIHR and many other contributors, this of structurally and functionally diverse extracellular matrix (ECM) molecules. In addition toconference has attracted investigators and students from 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 decipheracross the globe who share significant interest in animal the precise morphogenetic contributions of SPARC (Secreted Protein, Acidic, Rich in Cysteine) during normal and pathological development. SPARC is a small, collagen- andmodels of human disease. calcium-binding “matricellular” glycoprotein that is expressed at high levels in tissue In the era of personalized medicine, we look to the undergoing morphogenesis, remodeling or wound repair. SPARC has also attracted considerable interest due to its altered expression during progression of diverse diseasestranslation of molecular and cellular mechanisms of disease (e.g. fibrosis and cancer). Our studies with the cnidarian starlet sea anemoneinto innovative bedside applications. The necessary Nematostella vectensis indicate that the collagen-binding domain of SPARC is conserved throughout metazoan evolution. We have used the African clawed frog Xenopus laevis tointermediate step is the study of animal models in which the demonstrate a critical requirement for SPARC during post-gastrula development.manipulation of genes, proteins, cells and systems to fully Specifically, SPARC, directly or indirectly, promotes cell-cell adhesion which is required for the maintenance of tissue integrity during organogenesis. Using the powerful molecularunderstand how human diseases are generated. This and genetic tools available for the fruit fly Drosophila melanogaster, our data indicate thatapproach enables the testing of new diagnostic and 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 andtherapeutic interventions that provide important new 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 ovariandirections in health care. May I wish all the participants cancer progression, in part due to its demonstrated ability to inhibit cell proliferation andsuccess in networking and establishing new opportunities for migration. We have recently shown using a chick chorioallantoic membrane assay that a mimetic peptide corresponding to the most evolutionary conserved domain of SPARCcollaboration during this conference. I hope you also enjoy prevents endothelial cell branching angiogenesis. We plan to use this in vivo assay inToronto and our wonderful University of Toronto campus. 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 ofDr. Catharine Whiteside, MD, PhD, FRCPC, FCAHS the above models has offered unique insight into this ECM glycoprotein with complex Dean, Faculty of Medicine, Profesor of Medicine spatiotemporal distributions during embryogenesis and whose expression is altered in several disease states. University of Toronto
Dr. Corey Nislow Greetings for 1stInternational Assistant Professor, Conference of Models of Human Banting and Best Diseases Department of Medical On behalf of the Department of Laboratory Research, University of Medicine and Pathobiology of the University of Toronto, I would like to extend a warm Toronto 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.Gene-dose assays for drug discovery in yeast Lorelei and Rosalind Silverman, who work,and man respectively, as a Research Associate at the University of Toronto in theMy lab is interested in understanding the interaction of Department of Physiology (Supervisor: Dr. Milton Charlton) and as a Post-small molecules with their protein targets and target doctoral fellow, Department of Laboratory Medicine and Pathobiology (Supervisor: Dr. Michelle Bendeck). Earlier this year, Lorelei and Rosalindpathways. To accomplish this, we use comprehensive organized what has become a popular and highly successful seminar seriescollections of cells in which the gene dosage is on Animal Models of Human Disease at the University of Toronto, and forsystematically altered (decreased or increased). We have this International Conference the scope has been extended to also includeutilized the Yeast Knock Out collection (YKO) and cellular models.combined it with a collection of yeast overexpressing eachgene to screen thousands of bioactive small molecules The Canadian Institutes of Health Research, the major federalgenome-wide, identifying many novel gene-drug funding body of biomedical research in Canada, has providedinteractions. More recently we have expanded the scope of financial support for this International Conference in the form of athese gene-dose screens to other organisms and genomes. competitive award, and the engagement of additional sponsors is aFor example, we have successfully screened the human testament to the broad relevance and potential impact of this areaORFeome, expressed in yeast, with FDA approved of research. The ability for interested individuals from around thecompounds and have identified several known and novel world to engage in information and knowledge exchange in models of human disease is timely. People at all levels of expertise andinteractions. In collaboration with Jason Moffat’s laboratory, experience stand to benefit from participating in the discourse andweve initiated a large-scale effort to translate these gene- exploring new opportunities to form or strengthen researchdose screens to mammalian cells using pools of cells collaborations.infected with lentiviral-encoded shRNAs and human OFRs. Sincerest best wishes for an exciting, stimulating and successful meeting.I will present several compelling drug-target interactionsthat have been uncovered using a combination of these Richard G. Hegele, MD, FRCPC, PhDgene-dose screens as well as provide an overview of our Professor and Chairefforts to develop novel microarray and next-generation Department of Laboratory Medicine and Pathobiologysequencing technologies to accelerate the tempo of these University of Torontochemogenomic assays.
Dr. Lee Adamson Dr. Ronald Pearlman Director, Mouse Physiology Core, University Professor Centre for Modeling Human Emeritus and Senior Disease; Principal Investigator, Samuel Lunenfeld Research Scholar, Department of Institute of Mount Sinai Hospital; Biology, York University, Professor, Obstetrics and Toronto Gynaecology, U. of TorontoA decade of ENU mutagenesis at the Centre for The Ciliate Protozoan Tetrahymena thermophila asModeling Human Disease: Successes and an important animal model organism The ciliate protozoan Tetrahymena thermophila belongs to the Alveolates, a majorlessons learned 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 modelToronto’s Centre for Modeling Human Disease (CMHD) system for discovering fundamental principles of eukaryotic biology, it is the mostused dominant ENU-mutagenesis to generate new experimentally amenable member of the Alveolates and of the evolutionarily diverse ciliate species that colonize worldwide niches as free-living organisms, parasites, and mutualisticmouse models of disease from 2000-2010. The talk will symbionts. The ultrastructure, cell physiology, development, biochemistry, genetics, andhighlight some of our successes and challenges. We molecular biology of Tetrahymena havebeen extensively investigated and display a degree of structural and functionalcomplexity comparable to that of human and other metazoanphenotyped 9,600 first generation mice using broad- cells. Recentgenome sequencing projects have confirmed that these extensivebased, high-throughput screens. Of 2,218 outliers (2 andcomplex genomes conserve a rich set of ancestral eukaryotic functions. Tetrahymena has allowed major discoveries in biology such as catalytic RNA andSD), 293 were selected heritability testing. 127 were rybozymes (Nobel prize), variant nuclear genetic codes, telomeres and telomerase (Nobel prize), histone acetyl transferase as a transcription factor/co-activator, and recentlyheritable. 52 of the most interesting ones were mapped to discovered epigenetic phenomena acting at DNA (programmed somatic DNAchromosome location. So far, 26 point mutations are rearrangement), RNA (e.g. RNA interference), and protein levels. Unique among unicellular eukaryotes, ciliates separate germinal and somatic lines, in the form of nuclei.identified and 24 mutants are listed in the International Somatic development involves programmed rearrangements of the entire germline genomeMouse Strain Resource. Young adult mice were at each sexual generation and provides an excellent experimental model to study somatic DNA rearrangements similar to those that generate antibody diversity and malignant statesscreened for heart (15 heritable, 6 mapped, 2 cloned), in vertebrates. An impressive array of novel molecular genetic technologies placeblood (39 heritable, 13 mapped, 3 cloned), bone density 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(17 heritable, 5 mapped, 2 cloned), neurobehavior/ gene knockouts in the silent germline of heterokaryons; high frequency DNA transformationappearance (44 heritable, 23 mapped, 17 cloned), kidney with high-copy replicative vectors or by precise homologous recombination; easily manipulated inducible promoters allowing effective regulation of gene expression; gene(6 heritable, 2 mapped, 2 cloned), and other dysfunctions 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(5 heritable, 3 mapped, 0 cloned). 46 heritable lines have complementation. The richness of its genome makes this a useful model for addressingbeen distributed to 44 labs world-wide. CMHD’s cost- important questions including those with applications related to human health that cannot be investigated in other unicellular eukaryotic microbial systems. I will present an overviewrecovery phenotyping (www.cmhd.ca) has been used by of features of Tetrahymena making it a powerful animal model organism, focusing on170 investigators across Canada and USA. epigenetic mechanisms involving RNAi and heterochromatin in irreversible gene silencing.
Dr. Joseph Culotti Dr. Michelle Bendeck Professor, Department of Professor,Department of Molecular and Medical Laboratory Medicine and Genetics, University of Pathobiology,University of Toronto, Senior Investigator Toronto Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, CanadaMolecular mechanisms underlying cell and axon The role of the extracellular matrix in atheroscleroticmigrations in C. elegans inflammation, fibrosis and calcificationA novel TGF-beta and a G-protein coupled receptor are Interaction between cells and the extracellularinvolved in UNC-6/netrin mediated axon guidance and matrix provide structural support in the bloodcell migration in C. elegans.Jasmine Plummer and Joe Culotti. vessel, and allow the opportunity for signaling andThe netrin axon guidance and cell migration cue was first discovered as a mechanotransduction. Collagens are abundant inpredicted product of the unc-6 gene in C. elegans, where it was shown tomediate both attractive and repulsive responses depending on the repertoire the atherosclerotic plaque, and these moleculesof UNC-5/RCM and UNC-40/DCC receptors expressed by these cells. By play both protective and harmful roles inectopically expressing UNC-5 in specific sensory neurons that alreadyexpressed UNC-40, we made their axons switch from an attractive response to atherogenesis. My lab is studying the discoidina repulsive response to UNC-6. We showed the new ‘switched’ UNC-6-dependent guidance response was sensitized to the dose of unc-6(+) and domain receptor 1 (DDR1), a collagen-bindingused the ‘switched’ strain to carry out a genetic screen for suppressors of the receptor tyrosine kinase. We have recently‘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 described a critical role for DDR1 in atheroscleroticunc-40, showing the screen worked as hoped. We also discovered unc-129 - plaque development, regulating inflammation,mutations of cause motor axon guidance defects resulting in uncoordinatedlocomotion. We found that unc-129 encodes a novel TGF-beta that acts fibrosis, and calcification in a mouse model of thethrough a non-classical signaling mechanism to regulate sensitivity of growthcones to UNC-6. We also recently discovered a mutation that suppresses the disease. I will discuss our ongoing work to elucidate‘switched’ phenotype, which on its own does not normally cause motor axon the cellular, molecular and signaling mechanisms.guidance defects suggesting it has a redundant function with another guidancegene. This mutation identifies the seu-2 gene which we have found encodes a Taken together , our studies suggest that inhibitionnovel G-protein coupled receptor (GPCR) involved in both attractive and of DDR1 may be an important therapeutic target torepulsive responses to UNC-6. Finally, we have found that this GPCRfunctions in neurons whose axon guidance is affected by seu-2 mutations. limit inflammation, calcification and plaque growth,Since GPCRs are targets of most pharmaceuticals of clinical relevance, wehope that understanding how this GPCR functions will lead to improved and to promote stability.pharmacological interventions for human disorders that are sensitive toincreased or decreased netrin-mediated signaling.
Dr. Szczepan Baran Dr. Levon Khachigian President and Chief Director, UNSW Centre for Operating Officer, Veterinary Vascular Research, University Bioscience Institute in of New South Wales, Sydney, Harleysville, Pennsylvania AustraliaRat laparoscopic biopsies lead to decreased Immediate-early genes as master regulators in apostoperative pain wide range of vascular disordersThe refinement of current surgical techniques represents Cardiovascular disease and cancer remain the most prevalenta key opportunity to improve the welfare of laboratory causes of morbidity and mortality. The pathogenesis of these and arodents, while meeting legal and ethical obligations. myriad of related diseases is underpinned by molecular and cellularMinimally invasive surgery such as laparoscopy is changes in our blood vessels. Professor Khachigian’s research isconsidered the gold standard for many human uncovering key networks of transcriptional control and inducibleabdominal procedures. Laparoscopy results in gene-regulatory circuits that lead to vascular disease. The group isdecreased pain, decreased tissue trauma and more also developing new experimental drugs that have the potential to treat a diverse range of health problems, from cancer andrapid post surgical recovery. Compared to laparotomy, inflammation through to eye and heart disease. research programlaparoscopy preserves immune function when has two major objectives: 1. To better understand how harmfulequivalent procedures are performed. Many of these genes are controlled in vascular cells. This arm investigatesbenefits have been demonstrated in rodents with the signaling and transcriptional mechanisms of pro-inflammatoryexception of pain management. A pilot study was cytokine-dependent gene expression, post-translational mechanismsconducted using three groups; rats that had undergone that modify protein behavior, proteinase control, the isolation and characterization of new genes induced or repressed by vascular celllaparoscopic liver biopsy via laparoscopy, rats that had injury, and the molecular control of vascular cell migration andundergone liver biopsy via laparotomy, and rats exposed proliferation. The group has considerable expertise in animal modelsto inhalant anesthesia alone. Preliminary data, which of neointima formation, angiogenesis, tumor growth, myocardialincluded quantitative behavior analysis of assessing ischemia, and inflammation. 2. To develop new vascular therapeuticpost-operative pain, demonstrated that laparoscopic agents. The lab is harnessing the outcomes of its fundamentalprocedures lead to less post surgical pain than research by pioneering the development of novel “anti-gene-” and “gene-therapeutic” strategies targeting key regulatory genes in alaparotomy. Additional studies are required, but this myriad of vascular disorders. This involves strategic collaborationsinitial data suggest that laparoscopy in rodents might with a range of clinical specialists, academics and drug developmentrepresent a significant surgical refinement for the consultants.reduction of post-operative pain.
Dr. Adam Karpf Dr. Milton Charlton Associate Professor, Professor,Department of Roswell Park Cancer Physiology,University of Institute, Department Toronto of Pharmacology and Therapeutics Buffalo, NYDNA methylation in murine prostate cancer Squid, Frog, Crayfish, and Drosophila models inDNA methylation in mammals is a covalent modification of Neurosciencecytosine residues residing within CpG dinucleotides, and is Basic neuronal mechanisms are highly conserved and all discoveriescatalyzed by DNMT enzymes post DNA replication. DNA of these mechanisms made in Invertebrates have been confirmed latermethylation plays a critical role in mammalian development, in mammals. The large presynaptic terminal of the squid giantgenomic imprinting, transcriptional regulation, X-chromosome synapse allows voltage clamping of calcium currents and injection ofinactivation, and genomic stability. Notably, abnormalities in chemicals and proteins into the transmitter release sites. BasicDNA methylation are ubiquitous in human cancer. These concepts of calcium signaling were developed with this preparationchanges include both DNA hypermethylation and and these ideas were used in stroke research. The quantal nature ofhypomethylation, which occur at distinct regions of the genome. transmitter release was discovered in the frog neuromuscular junctionWhile substantial correlative data exist linking DNA methylation (NMJ). The regular array of active zones where exocytosis occurschanges to human cancer, in vivo model systems will be was exploited to examine the exclusive localization of calciumrequired to elucidate the functional role of these changes in channels. Invertebrate NMJs have been the source of severaltumor development and progression. Our laboratory is seminal discoveries in Neuroscience such as the mechanism ofconducting studies that utilize the TRansgenic Adenocarcinoma presynaptic inhibition. The crayfish NMJ has a small number ofof Mouse Prostate (TRAMP) model to define the nature and identified presynaptic axons of large enough diameter to permitcontribution of DNA methylation changes to prostate cancer. We intracellular recording and injection. Moreover, there is a huge degreehave observed that DNA methylation abnormalities occur in a of presynaptic differentiation; synapses of different motorneurons differtumor-stage specific manner, and correlate with gene expression wildly in presynaptic release properties. Therefore, one can ask howchanges. Furthermore, we have shown that reduced expression synapses become different as a natural growth process rather thanof the Dnmt1 enzyme in TRAMP significantly alters tumor during pesky learning paradigms. The Drosophila NMJ also has fewdevelopment. Most prominent among the changes observed is a motor neurons innervating each muscle fibre but they are much thinnerstriking reduction in tumor metastases. In summary, murine than in crayfish. However, Drosophila has the advantage of a knownmodels have proven useful for evaluating the functional genome and the availability of many mutants. Several mutations thecontribution of DNA methylation to prostate cancer. 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 Drosophila dynamin mutant which allows access to the vesicle lumen.
Dr. Zhong-Ping Feng Dr. David Rollo Associate Professor, Professor, Department of Department of Biology, McMaster University Physiology, University of TorontoLymnaea stagnalis, a multitalented model in Aging and Development of Successful Dietaryintegrative neurophysiologyThe freshwater pond snail, Lymnaea stagnalis (L. stagnalis) has Interventions: Lessons from Transgenicserved as a model for a wide spectrum of fundamental studies in Growth Hormone Mice That Express amolecular, cellular, and behavioral neurobiology. One of the Progeroid Syndrome of Accelerated Aging.major advantages of L. stagnalis is its simple central nervoussystem (CNS). The snail central neurons are large and many of Diverse pathologies including cardiovascular disease, stroke,them are individually identifiable, thus allowing diabetes, obesity, neurodegenerative conditions, cancer andelectrophysiological dissection of neuronal networks in vivo. inflammation are associated with elevated free radicalStudies using L. stagnalis as a model have made significant processes. Most of these are age-related so slowing agingcontributions in our understanding of the biophysical properties could ameliorate all of these conditions simultaneously.of neurons, synaptic transmission, and neural networks involved Dietary supplements composed of one or a few ingredientsin feeding, respiration, defensive withdrawal, locomotion, gravity have had little success. We formulated a complex dietaryorientation, reproduction, and learning and memory. Individual supplement targeting five key processes of aging and testedneurons that are identified as parts of defined behavioural it on normal mice and transgenic mice expressing acceleratedcircuits in adult animal can be isolated and maintained in cell aging. The supplement prevented age-related cognitiveculture, where synaptic connections reliably re-establish. This declines, forestalled bradykinesis (declining physical activity),property of the snail serves as an excellent tool to study the upregulated neurotransmitters, ameliorated radiation-inducedspecificity of synapse remodelling between adult neurons. We DNA damage and apoptosis, reversed declines inhave taken advantages of the CNS of L. stagnalis, in mitochondrial activity, and increased longevity. Remarkably,combination with acute targeted-gene silencing approaches, to the supplement reduced mitochondrial protein carbonyls peridentify novel cellular and molecular mechanisms in neuronal unit complex III activity by ~ 50%. Reduction of free radicalregeneration, synapse formation, memory formation, and hypoxic generation by mitochondria (a cleaner burn) is considered thestress. Our recent large-scale transcriptome sequencing and critical mechanism extending longevities in dietary restrictedproteomics analyses of the L. stagnalis CNS have identified a animals and birds and is considered the “silver bullet” fornumber of molecules that are orthologues to the genes related to aging interventions. Results provide proof of principle thatneurological disorders. In light of these new findings, the snail cocktails of dietary supplements may indeed extend youthfulmodel can be further used in functional genetics studies related function into older ages.to neurodegenerative and neurodevelopmental diseases.
Dr. Jack Uetrecht Dr. Thomas Koch Professor of Pharmacy and Adjunct Professor, Department Medicine, CRC Chair in of Biomedical Sciences, Ontario Veterinary College, U. Adverse Drug Reactions, of Guelph, Research Leslie Dan Faculty of Associate Orthopaedic Pharmacy, University of Research Laboratory, Aarhus Toronto University Hospital, DenmarkAnimal models to understand and ultimately Equine umbilical cord blood stem cell and tissueprevent idiosyncratic drug reactions engineering based therapies using the horse as aIdiosyncratic drug reactions (IDRs) are a major source of patient morbidity and pre-clinical animal model of orthopedic problemsmortality. They also significantly increase the risk of drug development because Stem cells and tissue engineering have received considerable attention due tothey are not discovered until very late in development and often after a drug has their potential therapeutic use in the past few decades although none of thebeen marketed. There is little known with certainty about their mechanisms and commercially approved products as of late 2002 had made a profit despite a totalwithout such understanding we are unlikely to make progress in predicting and industry investment in research and development exceeding US dollar 4.5 billion.preventing IDRs. Their unpredictability make prospective human mechanistic The causes of the inadequate return of these investments are undoubtlystudies impossible, and although animals can also have IDRs they are also multifacorial, but there is an emerging recognition in the biomedical field of theidiosyncratic in animals. Therefore, there are almost no valid animal models of need for intermediate animal models, which can bridge the proof-of-principleIDRs. We have developed one animal model in which nevirapine causes a skin studies in small laboratory animals and human clinical trials. The animal modelsrash in rats that is very similar to the rash that it causes in humans. This rash is of experimental induced arthroses currently used to assess biological safety andcaused by a metabolite of nevirapine and it is immune-mediated. In particular, efficacy appear fundamentally flawed. The reason being that the joint andsubstitution of deuterium for hydrogen on the molecule at the site of reactive cartilage environment of a spontaneously occurring lesion of possible long-lastingmetabolite formation decreases the incidence of rash and sensitivity to duration may very well be significantly different than the environment of limitednevirapine can be transferred to naïve animals with spleen cells. Depletion of acute injuries induced in a otherwise healthy joint. If this notion is accepted, thenCD4+ T cells is protective but depletion of CD8+ T cells appears to make the the cellular tissue response of both implanted and native cells and tissues mayrash worse. This model is very helpful in studies of how small molecules can also behave significantly differently. A number of domestic animals could servelead to an immune response. However, different drugs cause IDRs with different as models of spontaneous joint lesions. Specifically, comparative studies havecharacteristics and this presumably reflects mechanistic differences. Therefore, shown that the articular cartilage thickness of horses most closely resembles thatwe need several animal models to determine to what degree the mechanisms of of human articular cartilage. Both induced arthroses and spontaneous cartilagedifferent IDRs differ. We discovered the nevirapine model by accident, but if defects can be studied in the Horse. Spontaneous joint problems are a commonmost IDRs are caused by chemically reactive metabolites and immune- problem in horses and the familiarity of horses to being handled makes them anmediated it should be possible to develop new animal models by increasing the ideal species to evaluate selected rehabilitation programs. The significance ofproduction of reactive metabolites, stimulating the immune system and inhibiting weight-bearing/loading of joint immediately post-operatively is another importantimmune tolerance. However, despite several years of work, these strategies parameter that can be assessed using the horse as an animal model. This is ofhave not been successful. Furthermore, even though we know that the particular interest in human medicine where so-called fast-track surgerynevirapine-induced skin rash is immune-mediated, factors that would be programs are being increasingly implemented to decrease co-morbidities relatedexpected to increase its incidence/severity have not had the expected effects. to bed rest and inactivity post-operatively. The recent isolation of multipotentTherefore, our inability to develop animal models by trying to manipulate the mesenchymal stromal cells (MSCs) from equine umbilical cord blood makes for aimmune response to not mean that other IDRs are not immune-mediated. It very interesting research opportunity evaluating these cells utility in cartilagedoes indicate that we have a limited understanding of the immune system. repair in the horse.
Dr. John L. Wallace Dr. Jeffrey Henderson Director, Farncombe Family Associate Professor, Leslie Dan Faculty of Pharmacy, Digestive Health Research University of Toronto Institute, McMaster Director, Murine Imaging and University Histology (MIH) FacilityStudying Human GI Inflammation and Ulceration Development of Interactive Surgical and MultimodalUsing Rodent Models Atlases of the mouse CNS:Toward Integrative Neuroanatomic MeasuresInflammation plays in important role in the pathogenesisof several common diseases of the gastrointestinal (GI) Over the past quarter century genetically modified mice have emerged as major experimental models to probe fundamental aspects of thetract, including inflammatory bowel disease, celiac mammalian CNS; both during development and following injury. Thedisease, peptic ulcer and the gastroenteropathies morphologic effects resulting from a given gene targeting or CNS injuryassociated with the use of nonsteroidal anti- event frequently manifest itself at multiple neuroanatomic loci. Accurateinflammatory drugs (NSAIDs). Over the past few integrated interpretation and/or quantitative assessment of such features are often difficult or impossible to determine using standard histologicdecades, a great deal has been learned about the measures. In order to enhance investigators ability to more robustly analyzepathogenesis of these and other GI disorders through the effects of these and other interventions, we have developed two openthe use of animal models. For example, several rodent source tools toexamine the comparative neuroanatomy of the mouse CNS. In the first, we examined population-based variability of the CNS inmodels of colitis have been developed which have been 129S1/SvImJ,C57Bl/6J inbred and CD1 outbred strains of mice.exploited for testing of novel therapies, but also for Determining the limits of such natural variability represents a requisiteinvestigating potential mechanisms of tissue injury and precondition to provide confidence limits to any morphologic changes seenrepair. Similar, models of NSAID-induced GI injury have following intervention. In the second, we analyzed the brain and skull of numerous murine strains to develop a new more robust and accuratebeen widely employed to better understand these stereotactic coordinate system providing improved stereotactic accuracy.conditions, and to develop safer anti-inflammatory We have utilized these tools to develop the first detailed three dimensionaldrugs. These models have also been used to study understanding of how EphB-type receptors regulate guidance decisionsendogenous mediators of resolution of inflammation required for formation of the anterior commissure (AC) in the murine forebrain. Using this system we demonstrate for the first time that loss of(i.e., anti-inflammatory signals), and of healing. 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.