Premium
Adipose triglyceride lipase regulates basal lipolysis and lipid droplet size in adipocytes
Author(s) -
Miyoshi Hideaki,
Perfield James W.,
Obin Martin S.,
Greenberg Andrew S.
Publication year - 2008
Publication title -
journal of cellular biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.028
H-Index - 165
eISSN - 1097-4644
pISSN - 0730-2312
DOI - 10.1002/jcb.21964
Subject(s) - adipose triglyceride lipase , lipolysis , perilipin , hormone sensitive lipase , lipid droplet , lipogenesis , lipase , adipocyte , medicine , triglyceride , chemistry , endocrinology , adipose tissue , lipotoxicity , phosphatidic acid , microbiology and biotechnology , biology , biochemistry , enzyme , cholesterol , insulin resistance , insulin , phospholipid , membrane
In adipocytes, lipid droplet (LD) size reflects a balance of triglyceride synthesis (lipogenesis) and hydrolysis (lipolysis). Perilipin A (Peri A) is the most abundant phosphoprotein on the surface of adipocyte LDs and has a crucial role in lipid storage and lipolysis. Adipose triglyceride lipase (ATGL) and hormone‐sensitive lipase (HSL) are the major rate‐determining enzymes for lipolysis in adipocytes. Each of these proteins (Peri A, ATGL, and HSL) has been demonstrated to regulate lipid storage and release in the adipocyte. However, in the absence of protein kinase A (PKA) stimulation (basal state), the lipases (ATGL and HSL) are located mainly in the cytoplasm, and their contribution to basal rates of lipolysis and influence on LD size are poorly understood. In this study, we utilize an adenoviral system to knockdown or overexpress ATGL and HSL in an engineered model system of adipocytes in the presence or absence of Peri A. We are able to demonstrate in our experimental model system that in the basal state, LD size, triglyceride storage, and fatty acid release are mainly influenced by the expression of ATGL. These results demonstrate for the first time the relative contributions of ATGL, HSL, and Peri A on determination of LD size in the absence of PKA stimulation. J. Cell. Biochem. 105: 1430–1436, 2008. © 2008 Wiley‐Liss, Inc.