EXPRESSION OF PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR-ALPHA (PPAR-ALPHA) IN PRIMARY CULTURES OF HUMAN VASCULAR ENDOTHELIAL-CELLS

The peroxisome proliferator-activated receptor (PPAR) is a member of t he steroid nuclear receptor superfamily. Three types of PPARs have bee n described in humans: PPAR alpha, PPAR beta, and PPAR gamma. Here we investigated the levels of PPAR alpha mRNA in primary cultures of huma n umbilical venous endothelial cells (HUVEC), human umbilical arterial endothelial cells (HLTAEC), human coronary arterial endothelial cells (HCAEC), and human aortic endothelial cells (HAEC), using the reverse transcriptase-polymerase chain reaction (RTPCR). The HUVEC, HAEC, and HCAEC, but not the HUAEC, showed relatively low expression of PPAR al pha in comparison with liver, which was used as a positive control. Mo reover, the partial sequences of the PCR-amplified products from HUVEC , HAEC, and HCAEC were similar to that of the PPAR alpha from human li ver. The expression of PPAR alpha in cultured HAEC, which were induced by dexamethasone, was inhibited by insulin. In addition, PPAR alpha e xpression was also increased by bezafibrate or eicosapentaenoic acid w ith the physiological concentration. These results suggest that the PP AR alpha in endothelial cells may have the same physiological role as the expression of PPAR alpha in the liver. (C) 1998 Academic Press.