循环中游离脂肪酸增高与肥胖、胰岛素抵抗和2型糖尿病密切相关,其主要来源于脂肪细胞内甘油三酯水解。调控脂肪分解的脂肪酶主要包括激素敏感脂肪酶(hormone—sensitive lipase,HSL)和最近发现的脂肪组织甘油三酯水解酶(adipose triglyceride lipase,ATGL),后者主要分布在脂肪组织,特异水解甘油三酯为甘油二酯,其转录水平受多种因素调控。CGI-58(属于α/β水解酶家族蛋白),可以活化ATGL,基础条件下该蛋白和脂滴包被蛋白(perilipin)紧密结合于脂滴表面,蛋白激酶A激活刺激脂肪分解时,CGI-58与perilipin分离,进而活化ATGL。
Obesity, insulin resistance, and type 2 diabetes are associated with elevated concentration of circulating free fatty acids (FFAs) , which are critically governed by the process of triglyceride Iipolysis in adipocytes. Hormone-sensitive lipase (HSL) and adipose triglyceride lipase (ATGL) are two major enzymes in the control of triacylglycerol hydrolysis in adipose tissue. ATGL expressed predominantly in white adipose tissue specifically initiates triacylglycerol hydrolysis to generate diacylglycerols and FFA, a role distinguished from HSL that mainly hydrolyzes diacylglycerols. The transcription of ATGL is regulated by several factors. ATGL activity is regulated by CGI-58. Under basal conditions, interaction of CGI- 58 with a lipid droplet associating protein, perilipin, results in an inactivation of ATGL activity. During PKA-stimulated lipolysis, CGI-58 is released from phosphorylated perilipin and in turn, binds to ATGL. This action facilitates triglyceride lipolysis. This review focuses on the regulation and function of ATGL in adipose lipolysis and metabolism.