Role of NADPH oxidase in the regulation of vascular endothelial cell inflammation induced by hypochlorite-modified albumin / 中华肾脏病杂志

ABSTRACT

Objective To elucidate the mechanism of inflammation in vascular endothelial cells induced by hypochlorite-modified albumin (HOCl-Alb). Methods HOCl-Alb-induced NADPH oxidase activity in human umbilical vein endothelial cells (HUVEC) was measured by lucigenin-enhanced chemiluminescence. Phosphorylation of p47phox and binding of p47phox and p22phox were measured with immunoprecipitation and Western blotting. Membrane translocation of p47phox was measured with immunofluorescence. RT-PCR and Western blotting were used to determine the intercellular adhesion molecule-1 (ICAM-1) mRNA and protein expression in the presence or absence of apocynin, respectively. Results Co-incubation of HUVEC with HOClAlb resulted in the enhancement of NAIDPH oxidase activity in time- and dose-dependent manner.Compared with bovine serum albumin group, exposure of the cells with 200 mg/L HOCl-Alb for 15min resulted in a 6.16-fold increase in NADPH oxidase activity. Phosphorylation and membrane translocation of p47phox and binding of it with p22phox were also induced by HOCl-Alb. ICAM-1expression was up-regulated after exposure to HOCl-Alb and this effect was significantly abolished by apocynin, a specific inhibiter of NADPH oxidase, in dose-dependent manner. Preincubation of the cells with 500 μmol/L apocynin inhibited the expression of ICAM-1 protein induced by HOClAlb by 68.97% (P＜0.01). Conclusion NADPH oxidase plays a central role in HOCl-Albmediated ICAM-1 expression and provides a mechanism for HOCl-Alb-related vascular endothelial inflammation.