Roles of peroxisome proliferator-activated receptor gamma in cardiovascular disease

Peroxisome proliferator-activated receptors (PPARs) are transcription factors belonging to a nuclear receptor superfamily. PPARs have three isoforms: alpha, beta (or delta), and gamma. It is known that PPARgamma is expressed predominantly in adipose tissue and promotes adipocyte differentiation and glucose homeostasis. Recently, synthetic antidiabetic thiazolidinediones (TZDs) and the natural prostaglandin D2 (PGD2) metabolite, 15-deoxy-Delta(12,14)-prostaglandin J2 (15d-PGJ2), have been identified as ligands for PPARgamma. Furthermore, it has become apparent that PPARs are present both in a variety of different cell types and in atherosclerotic lesions and the studies about PPARgamma have been extended. Although activation of PPARgamma appears to have protective effects on atherosclerosis, it is still largely uncertain whether PPARgamma ligands prevent the development of cardiovascular disease. Recent evidence suggests that some benefit from antidiabetic agents, TZDs, may occur independent of increased insulin sensitivity. In this article, we review the latest developments in the PPAR field and summarize the roles of PPARgamma and the actions of PPARgamma ligands in the cardiovascular system.