The Effect Of HDL And Simvastadin On NADPH Oxidase And ROS In HUVEC

Background: Nicotinamide adenine dinucleotide phosphate oxidase(NADPH oxidase) is a multicomponent enzyme complex, which consists of 5 major subunits: a plasma membrance spanning cytochrome b558 composed of a large subunit gp91phox and a smaller p22phox subunit and 3 cytosolic components p47phox,p67phox and Rac.Upon stimulation,the three cytosolic components translocate to the membrance and assemble with cytochrome b558,resulting in enzyme activation and burst production of ROS.ROS of human vascular system mostly derive from NADPH oxidase.Gp91phox was firstly found in phagocyte cells.and the novel gp91phox homologues of NOX families such as NOX1, N0X3, N0X4, N0X5 have been found in different organs (colon, kidney, spleen) and vascular smooth muscle cells in recent years. Latest studies indicated that N0X4 gene may be important in the ROS generation in endothelial cells. Several cell types in the artery wall have been show to oxidise lipoprotein, including endothelial cells, smooth muscle cells, which proceed the progression of atherosclerosis. In the recent years, the antioxidant activity of high density lipoprotein (HDL) to directly impede some of processes in atherogenesis has receiving increasing attention. But the mechanism of HDL is not clear involving chelate of transition metal ions, a reservoir for lipid peroxides, HDL-associated enzymes. In these studies, we observed the change of N0X4, N0X2, p47phox, p67phox, p22phox and Rac expression and intracellular ROS level in HUVEC stimulated by HDL, simvastadin or apoAI before low density lipoprotein(LDL) addition.Objectives: To investigate the mRNA expression of p47phox, p67phox, p22phox and Rac gene in HUVEC; then to elucidate the change of N0X4, N0X2, p67phox, p22phox and Rac expression in HUVEC stimulated by HDL, simvastadin or apoAI before LDL addition.Methods: U937 cell was used as the positive control of mRNA expression of p47phox, p67phox, p22phox and Rac. N0X4, N0X2, p67phox, p22phox and Rac expression in HUVEC was measured by RT-PCR. N0X4 and N0X2 expression in HUVEC was...