[대학원 생명과학과 세미나 안내]
연사 : 김재범 교수(서울대학교 생명과학부)
연제 : Metabolic dysregulation in obesity
일시 : 2017년 3월 24일 (금) 오후 4시
장소 : 하나과학관 A동 109호
초청교수 : 김옥매 교수
Abstract
Adipose tissue plays key roles in whole body energy homeostasis. In obesity, adipocyte hypertrophy and pro-inflammatory responses are closely associated with the development of insulin resistance in adipose tissue. However, it is largely unknown whether adipocyte hypertrophy in the absence of inflammation is sufficient to induce insulin resistance. Recently, we have developed an adipocyte hypertrophy model by treating adipocytes with fatty acids. Treatment with saturated or monounsaturated fatty acids results in adipocyte hypertrophy, but a pro-inflammatory response is only observed in adipocytes treated with saturated fatty acids. Regardless of inflammation, hypertrophic adipocytes with unilocular lipid droplets exhibit impaired insulin-dependent glucose uptake with a defect in GLUT4 trafficking to the plasma membrane. Moreover, Toll-like receptor 4 mutant mice with diet-induced obesity are not protected against insulin resistance, although they are resistant to adipose tissue inflammation. Together, our in vitro and in vivo data suggest that adipocyte hypertrophy alone would be sufficient to cause insulin resistance independent of inflammation. In this presentation, I will discuss the structure and function of adipocytes and their relationship in the regulation of insulin sensitivity, which reveals the underlying mechanisms by which hypertrophic adipocytes would provoke insulin resistance in obesity.