Our Research Members
Professor, Departments of Medicine and Physiology
1 King's College Circle
Toronto, ON M5S 1A8
Research in the Gaisano lab is focused on molecular mechanisms regulating exocytosis, employing islet cells as models. We were one of the firsts to demonstrate that SNARE proteins originally found to mediate neurotransmitter release are conserved in non-neuronal cells, including the pancreatic islet to regulate secretion. We contributed to the original work showing SNARE protein regulation of insulin granule exocytosis, and subsequently contributed much of the work showing how SNARE proteins physically and functionally interact with beta-cell ion channels (Kv, KATP, Ca2+) to regulate the intricate sequence of ion fluxes, membrane potential and exocytotic fusion events leading to secretion. Current efforts are directed at: 1) SNARE proteins regulation of newcomer granule exocytosis and compound insulin granule fusion, and employing such molecules by viral gene transfer to rescue type 2 diabetes; 2) excitosome formation of SNAREs with Kv and Ca2+ channels during insulin granule docking and priming; and 3) islet alpha cell secretory mechanisms and crosstalk with beta- and delta-cells in health and their dysregulation in diabetes. This lab has in place a full spectrum of state-of-the-art single islet cell analyses for rodent and human islets, including patch clamp electrophysiology and capacitance measurements on dispersed cells and intact islets within pancreas slices, imaging of single granule exocytosis by TIRFM, single islet cell (beta, alpha and delta cells) imaging within whole islet by confocal and multi-photon microscopy, and high-resolution FRET analysis of molecular interactions.
This lab also has full capabilities to perform assays for in vivo glucose homeostasis, including glucose clamps and surgical pancreatic duct perfusion of viruses for in vivo rescue of diabetic rodent models; islet cell biology assays, including islet isolation, islet perifusion secretory assays, assessment of intact islets within pancreatic slices in diabetic models, E.M.; biochemistry (immunoprecipitation), molecular biology and viral gene transfer (adeno/AAV/lentivirus).
Professor, Department of Physiology and Department of Medicine
The primary theme of A.G.’s research is the investigation of the effects of excess circulating energy substrates, in particular free fatty acids, on insulin action, secretion and kinetics, and the implication of these effects for the pathogenesis of diabetes. Secondary themes of research are the studies of the effects of nutrient and insulin excess in animal models of atherosclerosis and cancer .
Professor, Department of Medicine
Head, Division of Endocrinology & Metabolism, St. Michael’s Hospital
Canada Research Chair in Diabetes Complications
Research in the Gilbert lab focuses on the pathogenesis of diabetes complications as a way to evolve new therapies to prevent their development and attenuate their progression. Current projects involve translational research in diabetic nephropathy, retinopathy and heart failure, exploring novel pharmacological treatments and the use of adult stem cells to regenerate diseased tissue.
Assistant Professor, Faculty of Kinesiology & Physical Education
I am interested in understanding how exercise and nutrition impact carbohydrate and fat metabolism in humans, and identifying lifestyles strategies to improve metabolic health. This ranges from conducting studies in young healthy adults to those at risk for, or afflicted with, metabolic disease. We are interested in practical questions relating to the importance of exercise dose (e.g., intensity vs. duration), mode (e.g., aerobic vs. resistance), and timing (e.g., before vs. after a meal) on indices of metabolic health such as insulin sensitivity and cardiorespiratory fitness. We are also interested in exploring sex-based differences in the adaptive response to exercise and nutritional interventions in an effort to provide sex-specific recommendations for improved health of Canadians.
Associate Professor, Department of Laboratory Medicine & Pathobiology
Academic Director, Microscopy Imaging Laboratories (MIL), Faculty of Medicine
We study the role of a mitochondrial named NLRX1 in diabetes. Our preliminary research has identified that NLRX1 plays a role in the regulation of body weight and of obseity-induced diabetes in vivo. Because NLRX1 was identified as a key regulator of apoptosis during inflammation, we are interested in identifying how this mitochondrial protein links obesity and diabetes with inflammation and cell death.
Professor, Department of Family and Community Medicine
Senior Scientist, Institute for Clinical Evaluative Sciences
Scientist, Centre for Research on Inner City Health, St. Michael’s Hospital
30 Bond Street
Toronto, ON M5B 1W8
Phone: 416-864-6060 x77444
Diabetes in primary care – processes of care, impact of incentives, health disparities.
Risk factors for diabetes, especially socioeconomic status, ethnoracial background and immigration, neighbourhood walkability.
Associate Professor, Faculty of Dentistry; Faculty of Medicine
Hospital For Sick Children, Mount Sinai Hospital, Sunnybrook Health Sciences Centre, and Toronto Rehab
Impact of diabetes on innate immunity and neutrophil functions. Impact of diabetes on oral health and periodontal diseases. Impact of diabetes on osteoimmunology.
Professor, Department of Nutritional Sciences
Senior Scientist, Rotman Research Institute, Baycrest
Research in the Greenwood lab is focused on understanding the effect of diet and metabolic disorders, including type 2 diabetes, on the retention or loss of cognitive function with aging. Our studies, in both humans and animal models, show that the consumption of diets which promote obesity and type 2 diabetes are associated with more rapid decline in cognitive function. By contrast, consumption of healthy diets associates with retention of cognitive function. Our current interest lies in understanding the adverse brain effects of type 2 diabetes. These studies draw on functional magnetic resonance imaging as a means of determining underlying neuronal pathways and neuronal responses which are impacted.
Professor, Department of Laboratory Medicine and Pathobiology
Director, Bone and Mineral Group
Our research focuses on the effects of diabetes on the skeletal system using pre-clinical models. Examples of our research includes:
1) Effect of Vanadium Treatment on Bone Loss and Bone Quality in Rat Models of Diabetes. Vanadium compounds have been shown to be effective in experimental diabetes and insulin-resistant hypertension. However, these agents are known to accumulate in bone mineral where vanadate substitutes for phosphate. It is therefore essential to understand the long-term effects on these compounds on bone quality. (Facchini DM, Yuen VG, Battell ML, McNeill JH, Grynpas MD. The effects of vanadium treatment on bone in diabetic and non-diabetic rats. Bone. 2006; 38(3):368-77)
2) The effect of Rosiglitazone treatment on bone quality in rat models of type 2 diabetes and osteoporosis. Rosiglitazone (RSG) is an insulin-sensitizing drug used to treat patients with Type 2 Diabetes Mellitus (T2DM) to improve glycemic control. The ADOPT clinical trial showed that women taking RSG experienced more fractures. The purpose of our study is to understand the mechanism by which RSG induces limb fracture and alters bone quality in the insulin resistant Zucker Fatty rat.
3) Comparison of the skeletal effects in the treatment of type2 diabetes with Sitagliptin (a DPP4 inhibitor) or Pioglitazone (a PPRgamma agonist) in mice fed a high fat diet.