H2O2 but not O2- elevated by oxidized LDL enhances human aortic smooth muscle cell proliferation.
The oxidation of low density lipoprotein (LDL) as a key event in atherosclerosis suggests that antioxidant interventions may reduce the risk of atherosclerosis. However, the better strategies among antioxidant remedies for atherosclerosis remains difficult to be determined. Here, we show that oxidized LDL increases the steady-state level of intracellular hydrogen peroxide through stimulating the protein expressions of Nox1 and Cu/Zn superoxide dismutase (SOD) in human aortic smooth muscle cells (SMCs). The intracellular content of hydrogen peroxide rather than superoxide is a key modulator for vascular SMC (VSMC) proliferation, implying that without co-expression of catalase, increased Cu/Zn-SOD activity alone may not be beneficial to reduce the growth of VSMC in an atherosclerotic plaque.
Yin
Chi-Chao
CC
Department of Chemical Engineering, National Chung Cheng University, Chia-Yi, 621, Taiwan.
Huang
Kuang-Tse
KT
D001011:Aorta / Q000187:drug effects* / Q000378:metabolism; D049109:Cell Proliferation; D019069:Cell Respiration; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism*; D008077:Lipoproteins, LDL / Q000737:chemistry* / Q000494:pharmacology*; D008928:Mitochondria / Q000201:enzymology; D032389:Myocytes, Smooth Muscle / Q000187:drug effects* / Q000378:metabolism; D000074624:NADPH Oxidase 1; D019255:NADPH Oxidases / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism
D008077:Lipoproteins, LDL; D006861:Hydrogen Peroxide; D013482:Superoxide Dismutase; D000074624:NADPH Oxidase 1; D019255:NADPH Oxidases; C402799:NOX1 protein, human; D010100:Oxygen