Anti-inflammatory Effect of Peroxisome Proliferator Activated Receptor Gamma on Human Dental Pulp Cells

Peroxisome proliferator activated receptor gamma (PPARγ) plays a critical role in controlling immune and inflammatory responses. However, its effect on pulpal inflammation has not been clarified. The purpose of this study was to determine the anti-inflammatory effect of PPARγ on pulpal inflammation. Human dental pulp cells treated with lipopolysaccharide exhibited elevated levels of matrix metalloproteinase-2 (MMP-2), MMP-9, intracellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1). However, when treated with rosiglitazone (PPARγ agonist) or adenoviral PPARγ in same culture system, the expression of ICAM-1 and VCAM-1 was markedly inhibited along with decreased secretion of MMPs. In addition, the coadministration of GW9662 (PPARγ antagonist) and rosiglitazone blocked the inhibition of MMP-2, MMP-9, ICAM-1, and VCAM-1. These results suggest that PPARγ decreased the production of MMPs, ICAM-1, and VCAM-1 and might offer a possible attempt of using it as one of anti-inflammatory modulators in a pulpal inflammation.