PPARs and their Effects on the Cardiovascular System

Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors belonging to the nuclear receptor superfamily that undergo transactivation or transrepression by distinct mechanisms leading to induction or repression of expression of target genes. The PPAR family consists of three isoforms, alpha,gamma, and beta/delta, which share similar structural organization, possess distinct functions, and vary in their ligand affinity, expression, and activity in different metabolic pathways in different tissues. PPARs are involved in many functions especially those involved in the regulation of vascular tone, inflammation and energy homeostasis and therefore represent important targets for hypertension, obesity, obesity-induced inflammation, and metabolic syndrome in general. PPARs may influence the inflammatory response either by direct transcriptional downregulation of proinflammatory genes via mechanisms involving transrepression, or indirectly via their transcriptional effects on lipid metabolism. On account of their pleiotropic effects, they are now known to be active participants in many disease conditions and they represent potent targets for the development of therapy of a wide array of diseases.