摘要
目的观察血管紧张素Ⅱ(angiotensinⅡ,AngⅡ)是否可诱导体外培养的人脐静脉内皮细胞(Hu-manumbilicalveinendothelialcells,HUVECs)衰老,并探讨其作用机制。方法体外培养的HUVECs分为对照组、AngⅡ组、AngⅡ+valsartan组,观察细胞衰老改变及超氧阴离子(O·2-)水平,分析各组细胞AngⅡ1型和2型受体(AT1R和AT2R)、NAD(P)H氧化酶p22phox的mRNA及蛋白表达。结果给予AngⅡ后,β-gal染色阳性细胞数增加,细胞向G0-G1期停滞,细胞p16蛋白表达增高,出现衰老的特征性改变;衰老细胞NO生成减少,O·2-生成增加,p22phox和AT2R的mRNA及蛋白表达增加,AT1R表达下降;valsartan处理后改善了细胞的衰老改变,下调p22phox表达,降低O·2-水平,对AT2R表达无明显影响。结论AngⅡ可诱导体外培养的HUVECs衰老,AngⅡ从转录水平上调NAD(P)H氧化酶p22phox表达,进而使O·2-产生增加可能是诱导内皮细胞衰老的主要原因之一;Valsartan通过特异性阻断AT1R有一定的逆转内皮细胞衰老的作用。
[Objective] To study if angiotensin Ⅱ （Ang Ⅱ） 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, Ang Ⅱ group（stimulated with 10^-6 mol/L Ang lI for 48 h）, Ang Ⅱ plus valsartan group （valsartan was added to cells lh before 10^-6 mol/L Ang Ⅱ）. Superexide（OF） level in cells and medium were exam- ined. 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] Ang Ⅱ 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 ceils produced less NO and more O2^-·. The mRNA and protein expression of p22phox and AT2R in cells stimulated with Ang Ⅱ increased, the expression of AT1R decreased; valsartan treatment alleviated aging associated changes, decreased O2^-· production and increased NO production, and downregulated the mRNA and protein expression of p22phox. [Conclusion] The study indicated Ang Ⅱ upregulates the expression of NAD （P）H oxidase sub- unit-p22phox at the transcriptional degree, hence increases O2^-· production and ultimately induces HUVECs in vitro senescent; valsartan treatment protects endothelial ceils from aging at a certain extent.
出处
《中国现代医学杂志》
CAS
CSCD
北大核心
2007年第1期51-55,共5页
China Journal of Modern Medicine
