Anti-inflammatory mechanisms of the vascular smooth muscle PPARγ

This review highlights molecular mechanisms of anti-inflammatory and protective effects of the nuclear transcription factor, peroxisome proliferator-activated receptor γ (PPARγ) in vascular tissue. PPARγ is an ubiquitously expressed nuclear factor, and well-studied in adipose tissue and inflammatory cells. Additionally, beneficial effects of vascular PPARγ’s on atherosclerosis and vascular remodeling/dysfunction have been reported although the detailed mechanism remains to be completely elucidated. Clinical and basic studies have shown that the synthetic PPARγ ligands, thiazolidinediones (TZDs), have protective effects against cardiovascular diseases such as atherosclerosis. Recent studies utilizing genetic tools suggested that those protective effects of TZDs on cardiovascular diseases are not due to a consequence of improvement of insulin resistance, but may be due to a direct effect on PPARγ’s in vascular endothelial and smooth muscle cells. In this review, we discuss proposed mechanisms by which the vascular PPARγ regulates vascular inflammation and remodeling/dysfunction especially in smooth muscle cells.