Qiang
Tong, Ph.D.
Assistant Professor of Pediatrics
Baylor College of Medicine
qtong@bcm.tmc.edu
Molecular Mechanisms of Metabolic Regulation in Obesity, Diabetes and Aging
The main focus of our lab is to study the function of adipose tissue, as well as other metabolic organs, such as muscle, heart, and liver in metabolic diseases and aging. Our major approach is to study the molecular mechanism of caloric restriction. Dietary caloric restriction is the only known non-genetic method to extend animal life span. It also reduces the onset of age-related diseases, such as obesity, diabetes, neurodegenerative and cardiovascular diseases and cancer. The study of the molecular mechanism of caloric restriction may lead to pharmaceutical treatments that mimic dietary restriction’s beneficial effects.
Sir2 gene, which encodes NAD-dependent deacetylase, was found to mediate the effect of caloric restriction on life span extension in yeast, C.elegans and fruit flies. Sirtuin activator resveratrol has been found to extend life span in many organisms. We have demonstrated that the expressions of two of the seven mammalian Sir2 homologues, SIRT2 and SIRT3, are regulated in response to nutrient uptake, cold exposure or oxidative stress. We have illustrated the molecular mechanism of SIRT2’s action in oxidative stress resistance and inhibition of adipocyte (fat cell) formation. We have also shown how SIRT3 activates adaptive thermogenesis (heat producing process) in the brown adipose tissue and the how SIRT3 regulates glucose disposal and fat oxidation in skeletal muscle. We and others have found that resveratrol protects mice against high-fat diet induced metabolic defects. Researches are under way to continue investigating the cellular functions and animal models of sirtuins.
Another research direction of our lab is to study the adipose tissue function. By investigating how mature adipocytes are derived from multipotent stem cells we may gain insights into obesity prevention. In addition, by studying how fat metabolism and its endocrine secretion influence whole body metabolism, we may learn how obesity leads to insulin resistance and subsequent type-2 diabetes.
Representative Publications:
Fei Wang, Margaret Nguyen, F. Xiao-Feng Qin, and Qiang Tong (2007) SIRT2 Deacetylates FOXO3a in Response to Oxidative Stress and Caloric Restriction. Aging Cell, 6:505-14.
Judy Tsai, Qiang Tong, Guo Tan, Aaron N. Chang, Stuart H. Orkin and Gökhan S. Hotamisligil (2005) GATA-2 Suppresses Differentiation and Adrenergic Response in Brown Adipocytes, EMBO Reports, 6(9):879-84.
Tong Shi, Fei Wang, Emily Stieren, and Qiang Tong (2005) SIRT3, A Mitochondrial Sirtuin Deacetylase, Regulates Mitochondrial Function And Thermogenesis In Brown Adipocytes, The Journal of Biological Chemistry. 280(14):13560-13567.
Qiang Tong, Judy Tsai, Guo Tan, Gökhan Dalgin, and Gökhan S. Hotamisligil (2005) Interaction Between GATA and the C/EBP Family of Transcription Factors is Critical in GATA-Mediated Suppression of Adipocyte Differentiation, Molecular and Cellular Biology, Vol. 25(2):706-715.
Qiang Tong, Jean-Louis Sankalé, Colleen M. Hadigan, Guo Tan, Eric S. Rosenberg, Phyllis J. Kanki, Steven K. Grinspoon and Gökhan S. Hotamisligil (2003) Regulation of Adiponectin In HIV-Infected Patients: Relationship to Body Composition and Metabolic Indices, Journal of Clinical Endocrinology & Metabolism, Vol. 88(4):1559-64.
Qiang Tong, Gökhan Dalgin, Haiyan Xu, Chao-Nan Ting, Jeffrey M. Leiden and Gökhan S. Hotamisligil (2000) Function of GATA Transcription Factors in Preadipocyte-Adipocyte Transition. Science, Vol. 290, 134-138.
