NADPH oxidase-derived reactive oxygen species involved in angiotensin Ⅱ-induced monocyte chemoattractant protein-1 expression in mesangial cells

Objective To investigate the origin of oxidative stress induced by angiotensin H (Ang Ⅱ ) in human mesangial cells and the role of reactive oxygen species ( ROS) in Ang Ⅱ -induced monocyte chemoattractant protein-1 (MCP-1) expression.Methods MCP-1 expression was determined by real time RT-PCR.ROS production was measured by DCFDA fluorescence.Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity was examined by lucigenin chemiluminescence.p47phox and p67phox translocation was assayed by Western blot.Twenty-four male mice were randomly divided into three groups; the control,the Ang Ⅱ infusion Ang Ⅱ 400 ng/(kg±min) ],and the apocynin treatment.Ang Ⅱ was infused by subcutaneously osmotic minipump for 14 days.Urinary albumin and 8-isoprostane excretion were measured by ELISA.Results In cultured human mesangial cells,Ang Ⅱ induced the MCP-1 expression in a dose-dependent manner with 3.56 fold increase as compared with the control.Ang Ⅱ increased intracellular ROS production as early as 3 min with the peak at 60 min and was in a time and dose-dependent.Incubation with different dosages of Ang Ⅱ ( 1μmol/L,10μmol/L,and 100μmol/L Ang Ⅱ ) for 60 min,ROS production increased at 1.82,2.92,and 4.08 folds respectively.Ang Ⅱ-induced ROS generation was sensitive to diphenyleneiodonium sulfate (DPI,10 μmol/L) and apocynin (500μmol/L) ,two structurally distinct NADPH oxidase inhibitors.In contrast,inhibitors of other oxidant- producing enzymes,including the mitochondrial complex I inhibitor rotenone,the xanthine oxidase inhibitor allopurinol,the cyclooxygenase inhibitor indomethacin,the lipoxygenase inhibitor nordihydroguiaretic acid,the cytochrome P450 oxygenase inhibitor ketoconazole and the nitric oxide synthase inhibitor G-nitro-L- arginine methyl ester were without an effect Ang Ⅱ -induced ROS generation was inhibited by the ATI antagonist losartan (10μmol/L) but not the AT2 antagonist PD123319 (10μmol/L).Ang Ⅱ treatment induced translocation of cytosolic of p47 and p67 to the membrane.The antioxidants almost abolished Ang Ⅱ -induced MCP-1 expression.Ang Ⅱ infusion increased urinary and p67 translocation by 2.69-,2.97-,and 2.67-fold,respectively.Conclusions NADPH oxidase-derived ROS is involved in Ang Ⅱ-induced MCP-1 expression.Inhibition of NADPH oxidase alleviates Ang Ⅱ -induced renal injury.