Study on angiotensinII inducing endothelial cell aging in vitro

[Objective] To study if angiotensin Ⅱ (AngⅡ) could induce human umbilical endothelial cells (HUVECs) aging, and to determine the possible mechanism. [Methods] The cultured HUVECs in vitro were divided into 3 groups, the control group, AngⅡgroup(stimulated with 10-6 mol/L AngⅡ for 48 h), AngⅡ plus valsartan group(valsartan was added to cells 1h before 10-6 mol/L AngⅡ ). Superoxide() level in cells and medium were examined. RT-PCR and Western blot were used to analyse mRNA and protein expression of NADPH oxidase p22phox, angiotensin type 1 and 2 receptor(AT1R,AT2R). [Results] AngⅡ stimulation enhanced the positive cell number of β-gal stained HUVEC, depressed cell proliferation, and increased the protein expression of P16, at the same time, stimulated cells produced less NO and more. The mRNA and protein expression of p22phox and AT2R in cells stimulated with AngⅡ increased, the expression of AT1R decreased; valsartan treatment alleviated aging associated changes, decreased production and increased NO production, and downregulated the mRNA and protein expression of p22phox. [Conclusion] The study indicated AngⅡ upregulates the expression of NAD(P)H oxidase subunit-p22phox at the transcriptional degree, hence increases production and ultimately induces HUVECs in vitro senescent; valsartan treatment protects endothelial cells from aging at a certain extent.