Expression of Peroxisome Proliferator-Activated Receptor α (PPARα) in Primary Cultures of Human Vascular Endothelial Cells

Abstract

The peroxisome proliferator-activated receptor (PPAR) is a member of the steroid nuclear receptor superfamily. Three types of PPARs have been described in humans: PPARα, PPARβ, and PPARγ. Here we investigated the levels of PPARα mRNA in primary cultures of human umbilical venous endothelial cells (HUVEC), human umbilical arterial endothelial cells (HUAEC), human coronary arterial endothelial cells (HCAEC), and human aortic endothelial cells (HAEC), using the reverse transcriptase-polymerase chain reaction (RT-PCR). The HUVEC, HAEC, and HCAEC, but not the HUAEC, showed relatively low expression of PPARα in comparison with liver, which was used as a positive control. Moreover, the partial sequences of the PCR-amplified products from HUVEC, HAEC, and HCAEC were similar to that of the PPARα from human liver. The expression of PPARα in cultured HAEC, which were induced by dexamethasone, was inhibited by insulin. In addition, PPARα expression was also increased by bezafibrate or eicosapentaenoic acid with the physiological concentration. These results suggest that the PPARα in endothelial cells may have the same physiological role as the expression of PPARα in the liver.