PPARs激动剂上调内皮细胞表达eNOS并增加NO生成

PPARs ligands antagonizes Ang-induced decrease in endothelial NO production by upregulating eNOS expression

目的:观察PPARα激动剂非诺贝特及PPARγ激动剂赛格列酮对人脐静脉内皮细胞(HUVECs)血管紧张素Ⅱ(AngⅡ)抑制NO生成的作用。方法:体外培养HUVECs,用1×10-7-1×10-4mol/L赛格列酮和10-5、10-4mol/L非诺贝特预处理HUVECs 24 h,再与10-6mol/L AngⅡ共同孵育12 h,通过RT-PCR和Western blotting分别检测eNOS mRNA和蛋白表达水平;通过Griees反应测定NO2-/NO3-浓度。结果:与对照组相比,10-7mol/L AngⅡ刺激HUVEC 12 h下调eNOS mRNA(0.38±0.19vs0.13±0.18,P<0.01)和蛋白(35.90±3.18vs6.95±2.19,P<0.01)表达,减少NO生成(50.21μmol/Lvs21.33μmol/L,P<0.01)。用10-7、10-6、10-51、0-4mol/L赛格列酮预处理24 h,上调eNOS mRNA表达(分别为0.36±0.03、0.36±0.14、0.37±0.16、0.43±0.06,与AngⅡ组比较,均P<0.01)和蛋白表达(分别为11.60±3.31、11.78±5.45、13.93±2.46、22.93±3.17,与AngⅡ组相比,均P<0.01),增加细胞培养液NO2-/NO3-浓度。非诺贝特也上调eNOS mRNA和蛋白表达,增加细胞培养液NO2-/NO3-浓度(P<0.01)。结论:AngⅡ减少eNOS表达,从而减少NO生成。赛格列酮和非诺贝特预处理24 h,可拮抗AngⅡ对HUVECs eNOS mRNA和蛋白表达的抑制作用,增加NO的释放。

AIM： We hypothesized that PPART ligands stimulate endothelial - derived nitric oxide （NO） release to protect the vascular wall. Thus, the purpose of this study is to investigate the effects of ciglitazone （Cig） and fenofibrate （Fen） on angiotensin Ⅱ （AngⅡ） - induced decrease in endothelial NO synthase （eNOS） expression and NO production in human umbilical vein endothelial cells （ HUVECs ）. METHODS： HUVECs were preincubated for 24 h with Cig （ 10^-7, 10^-6 ,10^-5, 10^-4 mol/L） or Fen （ 10^-5 and 10^-4 mol/L）, then incubated for 12 h with 10^-7 mol/L Ang 11 . Total RNA was extracted, and the expression of mRNA and protein of eNOS was assessed by RT - PCR and Western blotting. NO production was measured by Griees method. RESULTS： In the presence of 10^-7 moL/L AngⅡ for 12 h, NO production in cultured HUVECs was decreased （ P 〈0.01）. Cig and Fen pretreatments enhanced NO production （ P 〈 0.01 ） and antagonized Ang - induced decrease in eNOS mRNA and protein levels in HUVECs. CONCLUSION： PPART activator, eiglitazone, and PPARα activator, fenofibrate, antagonize Ang- induced decrease in endothelial NO production by directly upregulating eNOS expression.