EXPRESSION OF PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR-GAMMA (PPAR-GAMMA) IN RAT AORTIC SMOOTH-MUSCLE CELLS

Peroxisome proliferator-activated receptor gamma (PPAR gamma), a membe r of nuclear receptors, is expressed at a high level in adipose tissue and plays an important role in adipocyte differentiation. In the pres ent study, we identified the expression of PPAR gamma in rat aortic sm ooth muscle cells (RASMC) using reverse transcription-polymerase chain reaction and gel mobility shift assay. In addition, to investigate wh ether PPAR gamma in RASMC is functional or not, we examined the effect of two specific ligands for PPAR gamma, a thiazolidinedione anti-diab etic agent, troglitazone, and 15-deoxy-Delta(12,14)-prostaglandin J(2) , on the transcriptional activity of PPAR responsive element (PPRE). A significant increase in the activity of PPRE by addition of these lig ands was found. These results suggest that in RASMC, target genes for PPAR gamma may be activated by specific ligands for PPAR gamma through PPRE in their promoters. In conclusion, PPAR gamma is expressed and f unctional in vascular smooth muscle cells. (C) 1998 Academic Press.