题 目：Adipogenesis and the Biogenesis Lipid Droplet: Mechanistically Distinct Processes Connected by Phospholipids

主 讲：杨洪远  教授

时 间：2023年1月4日16:00-17:30

地 点：琳恩图书馆111报告厅

摘要：The differentiation of preadipocytes into mature adipocytes is accompanied by the formation of a giant, unilocular lipid droplet (LD). Mechanistically, however, LD biogenesis and adipogenesis are two distinct processes. Congenital generalized lipodystrophy, also known as Berardinelli-Seip congenital lipodystrophy (BSCL), is characterized by a near complete loss of adipose tissue, severe insulin resistance and hepatic steatosis. BSCL1 encodes a metabolic enzyme, 1-acylglycerol-3-phosphate O-acyltransferase 2/AGPAT2, and BSCL2 encodes seipin, a protein of unknown molecular function. We demonstrate that both AGPAT2 and seipin are required for the normal biogenesis of LDs, in addition to their essential role in adipogenesis. Mechanistically, both AGPAT2 and seipin function to maintain the normal level/distribution of phosphatidic acid in the endoplasmic reticulum (ER) and the inner nuclear membrane: seipin inhibits the activity of ER-localized glycerol-3-phosphate O-acyltransferases 3/4 (GPAT3/4) whereas AGPAT2 promotes the stability and activity of CDP-diacylglycerol synthases. Our results suggest that the level and distribution of phospholipids, e.g., phosphatidic acid, play important roles in both LD biogenesis and adipogenesis.  

嘉宾介绍：杨洪远，1993年毕业于北京大学医学部，获得医学学士学位，1998年于美国哥伦比亚大学获得博士学位，现任澳大利亚悉尼新南威尔士大学生物技术与生物分子科学学院教授，澳大利亚国立健康与医学研究理事会（NHMRC）高级研究员。长期致力于研究真核细胞及动物中的脂质储存与转运，先后发表约110篇同行评议的文章和书籍章节，刊登于Cell、Science、Molecular Cell, Developmental Cell, J Cell Biol., Nature Comms, Diabetes and Cell Reports等具有高影响力的权威期刊。现任 Journal of Cell Biology 的 Academic Editor. 目前的研究集中在脂滴和脂肪组织的发生，磷脂的合成与调控，以及胆固醇和磷脂在细胞内的运输。此外还在积极研发治疗癌症与脂肪肝的药物。