期刊名称:Proceedings of the National Academy of Sciences
印刷版ISSN:0027-8424
电子版ISSN:1091-6490
出版年度:2003
卷号:100
期号:12
页码:7265-7270
DOI:10.1073/pnas.1133870100
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:This study identifies monocyte chemoattractant protein 1 (MCP-1) as an insulin-responsive gene. It also shows that insulin induces substantial expression and secretion of MCP-1 both in vitro in insulin-resistant (IR) 3T3-L1 adipocytes and in vivo in IR obese mice (ob/ob). Thus, MCP-1 resembles other previously described genes (e.g., PAI-1 and SREBP-1c) that remain sensitive to insulin in IR states. The hyperinsulinemia that frequently accompanies obesity and insulin resistance may therefore contribute to the altered expression of these and other genes in insulin target tissues. In vivo studies also demonstrate that MCP-1 is overexpressed in obese mice compared with their lean controls, and that white adipose tissue is a major source of MCP-1. The elevated MCP-1 may alter adipocyte function because addition of MCP-1 to differentiated adipocytes in vitro decreases insulin-stimulated glucose uptake and the expression of several adipogenic genes (LpL, adipsin, GLUT-4, aP2, {beta}3-adrenergic receptor, and peroxisome proliferator-activated receptor {gamma}). These results suggest that elevated MCP-1 may induce adipocyte dedifferentiation and contribute to pathologies associated with hyperinsulinemia and obesity, including type II diabetes.