Lipid metabolismPlasminogen activator inhibitor-1, adipose tissue and insulin resistanceAlessi, Marie-Christine; Poggi, Marjorie; Juhan-Vague, IrèneAuthor Information Laboratoire d'hématologie – Inserm UMR 626, Faculty of Medicine, Marseilles, France Correspondence to Alessi Marie-Christine, Laboratoire d'hématologie – Inserm UMR 626, Faculté de Médecine, 27 bd Jean Moulin, 13385 Marseille cedex 5, France Tel: +33 4 91 32 45 04; fax: +33 4 91 25 43 36; e-mail: [email protected] Current Opinion in Lipidology: June 2007 - Volume 18 - Issue 3 - p 240-245 doi: 10.1097/MOL.0b013e32814e6d29 Buy Metrics Abstract Purpose of review Plasminogen activator inhibitor (PAI)-1 is a physiological inhibitor of plasminogen activators (urokinase and tissue types) and vitronectin. It is synthesized by adipose tissue, and its levels in plasma are increased in obesity and reduced with weight loss. Circulating PAI-1 level predicts development of type 2 diabetes, suggesting that it may be causally related to development of obesity. A role for PAI-1 in development of obesity has only partially been established, however. This review summarizes current knowledge, gives context to developments thus far and discusses controversies. Recent findings In addition to its role in atherothrombosis, PAI-1 might be involved in adipose tissue development. PAI-1 is produced by ectopic fat depots under the influence of inducers. Among the most recently described inducers are inflammation, oxidative stress and circadian clock protein. PAI-1 may play several roles in contributing to obesity: through indirect effects on insulin signalling, by influencing adipocyte differentiation and by regulating recruitment of inflammatory cells within adipose tissue. Summary These recent findings emphasize the involvement of PAI-1 in controlling the biology of adipose tissue; PAI-1 is an attractive new therapeutic target to retard the metabolic complications that accompany obesity. © 2007 Lippincott Williams & Wilkins, Inc.