Peroxisome Proliferator-Activated Receptor ? Ligands Increase Lectin-Like Oxidized Low Density Lipoprotein Receptor-1 Expression in Vascular Endothelial Cells
Lectin-like oxidized low density lipoprotein receptor-1 (LOX-1) is a receptor for atherogenic oxidized LDL expressed in vascular endothelial cells, smooth muscle cells, and macrophages. Peroxiosme proliferator-activated receptors (PPARs) include subfamilies PPAR? and PPAR?, which are expressed in endothelial cells and involved in transcriptional regulation of a large number of genes that affect lipoprotein and fatty acid metabolism as well as inflammation. We therefore explored the effects of PPAR? and PPAR? ligands on expression of LOX-1. Treatment of cultured bovine aortic endothelial cells (BAECs) with PPAR? ligands (fenofibrate and WY14643) remarkably upregulated LOX-1 expression, which was detected by western and northern blot analyses. LOX-1 promoter-reporter gene assay showed that PPAR? ligands activate transcription of the LOX-1 gene. PPAR? ligands, in contrast, did not significantly affect LOX-1 expression in BAECs. PPAR? appears to be a key regulator in promoting LOX-1 expression in BAECs. Upregulated expression of LOX-1 may modulate the catabolism of oxidized LDL and atherosclerotic progression.
peroxisome proliferator-activated receptor ? ligands oxidized low density lipoprotein receptor-1 vascular endothelial cells lox-1 ppar? ppar?