缬沙坦对尾加压素Ⅱ诱导肾小管上皮细胞凋亡的影响

EFFECT OF VALSARTAN ON UROTENSIN Ⅱ INDUCED-APOPTOSIS IN HUMAN KIDNEY PROXIMAL TUBULAR EPITHELIAL CELL

目的观察缬沙坦对尾加压素Ⅱ(urotensinⅡ,UⅡ)对肾小管上皮细胞凋亡的影响。方法将体外培养人肾小管上皮细胞(human kidney proximal tubular cell,HK-2)分为正常对照组、10^(-8)mol/L UⅡ刺激组和10^(-8)mol/L UⅡ+10μmol/L缬沙坦组。采用Armexin V-FITC/PI双染法流式细胞术(flow cytometry,FCM)检测细胞凋亡百分比;Western-Blot检测Bax、Bcl-2的表达;荧光实时定量PCR(Real time-PCR)检测Bax、Bcl-2mRNA水平变化。结果①FCM法检测显示,与正常对照组相比,10^(-8)mol/L UⅡ刺激组细胞凋亡百分比显著升高(P<0.01)。10μmol/L缬沙坦能显著降低10^(-8)mol/L UⅡ诱导细胞凋亡的百分比(P<0.01)。②Western-Blot显示,10^(-8)mol/L UⅡ刺激组,与正常对照组相比,Bcl-2表达显著降低(P<0.05),Bax蛋白表达无明显变化(P>0.05),Bax/Bcl-2比率明显升高(P<0.01)。与UⅡ刺激组相比,缬沙坦使Bcl-2表达显著升高(P<0.01),Bax蛋白表达无明显变化(P>0.05),Bax/Bcl-2比率明显降低(P<0.01)。③Real time-PCR显示,10^(-8)mol/L UⅡ刺激组细胞Bcl-2mRNA表达显著减少(P<0.01),BaxmRNA无明显变化(P>0.05)。与UⅡ刺激组相比,缬沙坦显著升高Bcl-2mRNA水平(P<0.01),BaxmRNA无明显变化(P>0.05)。结论缬沙坦的肾脏保护作用可能部分是通过抑制UⅡ诱导的肾小管上皮细胞凋亡实现的。

Objective To observe the effect of valsartan on urotensin Ⅱ（U Ⅱ） induced- apoptosis in human kidney proximal tubular cell （HK-2）. Methods HK-2 cells were divided into three groups ： normal group, 10 -Smol/L U Ⅱ group, 10 -Smol/L U Ⅱ ＋ 10μmol/L Val group. Cells were stained by annexin V/propidium iodide （PI） and apoptosis of HK-2 was analyzed by flow cytometry （FCM）. The expression levels of Bax and Bcl-2 were observed by Western-Blot. Real time-PCR was performed to assess the levels of Bax, Bcl-2mRNA. Results Compared with normal group （ NG）, the percentage of cell apoptosis significantly increased in HK-2 in U Ⅱ stimulation group （ P 〈 0. 01 ）. FCM showed that valsartan made the cell apoptioic rate much lower than that of HK-2 of U Ⅱ -induced. The expressions of Bcl-2 protein and mRNA were decreased in U U -stimulated HK-2 ceils （ P 〈 0.05 ）. Valsartan could up- regulate the expression of Bcl-2 protein and mRNA but it did not have any effect on the expression of Bax. The ratio of Bax/Bcl-2 was significantly increased in U Ⅱ-stimulated HK-2 cells （P 〈 0.01 ）. Valsartan could also greatly ameliorate the increase of ratio of Bax/Bcl-2 （ P 〈 0. 01 ）. ConclusionValsartan has some renal protective effects on renal interstitial fibrosis, partly through inhibiting U Ⅱ induced-apoptosis in human kidney proximal tubular cell.