目的 探讨贝那普利对氧化低密度脂蛋白（ox-LDL）诱导的肾小管上皮NRK-52E细胞间质转化（EMT）及转化生长因子-β（TGF-β）/Smad通路的影响。方法 体外培养NRK-52E细胞，分为对照组、ox-LDL组（50μg/mL ox-LDL）、贝那普利组（50 μg/mL ox-LDL＋10 μmol/L贝那普利）、TGF-β1组（50μg/mL ox-LDL＋5 ng/mL TGF-β1）、贝那普利＋TGF-β1组（50 μg/mL ox-LDL＋5 ng/mL TGF-β1＋10 μmol/L贝那普利）。高倍光学显微镜观察各组NRK-52E细胞表型变化；免疫荧光染色法检测EMT标志性蛋白α-SMA、E-cadherin荧光强度；免疫印迹法检测各组NRK-52E细胞中α-SMA、E-cadherin蛋白及TGF-β/Smad通路蛋白表达水平。结果 与对照组比较，ox-LDL组梭形或不规则形细胞增多，α-SMA荧光强度及α-SMA、TGF-β1、p-Smad2/Smad2、p-Smad3/Smad3蛋白量显著升高（P<0.05）；E-cadherin荧光表达强度减弱，蛋白量明显降低（P<0.05）。与ox-LDL组比较，贝那普利组细胞表型改变明显减轻，α-SMA荧光表达强度明显减弱，α-SMA、TGF-β1、p-Smad2/Smad2、p-Smad3/Smad3蛋白量显著降低（P<0.05），E-cadherin荧光表达强度及蛋白量明显升高（P<0.05）；TGF-β1组细胞α-SMA荧光表达强度及α-SMA、TGF-β1、p-Smad2/Smad2、p-Smad3/Smad3蛋白量显著升高（P<0.05），E-cadherin荧光表达强度及蛋白量明显降低（P<0.05）。与贝那普利组比较，贝那普利＋TGF-β1组细胞α-SMA荧光表达强度明显增强，α-SMA、TGF-β1、p-Smad2/Smad2、p-Smad3/Smad3蛋白量显著升高（P<0.05），E-cadherin荧光表达强度及蛋白量明显降低（P<0.05）。与TGF-β1组比较，贝那普利＋TGF-β1组细胞α-SMA荧光表达强度及α-SMA、TGF-β1、p-Smad2/Smad2、p-Smad3/Smad3蛋白量显著降低（P<0.05），E-cadherin荧光表达强度及蛋白量明显升高（P<0.05）。结论 贝那普利可逆转ox-LDL诱导的肾小管上皮NRK-52E细胞间质转化的发生，机制可能是通过抑制TGF-β/Smad通路活化而发挥作用。

Objective To investigate the effects of benazepril on ox-LDL-induced epithelial mesenchymal transition (EMT) and TGF-β/Smad pathway in renal tubular epithelial NRK-52E cells. Methods NRK-52E cells were cultured in vitro and divided into control group, ox-LDL group (50 μg/mL ox-LDL), benazepril group (50 μg/mL ox-LDL + 10 μmol/L benazepril), TGF-β1 group (50 μg/mL ox-LDL + 5 ng/mL TGF-β1), and benazepril + TGF-β1 group (50 μg/mL ox-LDL + 5 ng/mL TGF-β1 + 10 μmol/L benazepril). The phenotypic changes of NRK-52E cells were observed by high power optical microscope, the fluorescence intensity of α-SMA and E-cadherin was detected by immunofluorescence staining, Western blot was used to detect the expression of α-SMA, E-cadherin and TGF-β/Smad pathway protein in NRK-52E cells. Results Compared with the control group, the number of spindle or irregular cells in ox-LDL group was more, the fluorescence intensity of α-SMA, α-SMA, TGF-β1, p-Smad2/Smad2, p-Smad3/Smad3 protein were significantly higher (P < 0.05), the fluorescence intensity and protein quantity of E-cadherin were significantly weaker and lower respectively (P < 0.05). Compared with those in ox-LDL group, the phenotypic changes of benazepril group were significantly reduced, the fluorescence intensity of α-SMA was significantly weaker, the protein levels of α-SMA, TGF-β1, p-Smad2/Smad2, and p-Smad3/Smad3 were significantly lower (P < 0.05), the fluorescence intensity and protein quantity of E-cadherin were significantly stronger and higher respectively (P < 0.05). In the TGF-β1 group, the fluorescence intensity of α-SMA, α-SMA, TGF-β1, p-Smad2/Smad2, p-Smad3/Smad3 protein were significantly higher (P < 0.05), the fluorescence intensity and protein quantity of E-cadherin were significantly weaker and lower respectively (P < 0.05). Compared with benazepril group, the fluorescence intensity of α-SMA in benazepril + TGF-β group was significantly stronger, the protein levels of α-SMA, TGF-β1, p-Smad2/Smad2, and p-Smad3/Smad3 were significantly higher (P < 0.05), the fluorescence intensity and protein quantity of E-cadherin were significantly weaker and lower respectively (P < 0.05). Compared with those in TGF-β1 group, the fluorescence intensity of α-SMA, α-SMA, TGF-β1, p-Smad2/Smad2, p-Smad3/Smad3 protein in the benazepril + TGF-β1 group were significantly lower (P < 0.05), the fluorescence intensity and protein quantity of E-cadherin were significantly stronger and higher respectively (P < 0.05). Conclusion Benazepril can reverse ox-LDL-induced EMT in NRK-52E cells, it may play a role by inhibiting the activation of TGF-β/Smad pathway.

R965

河南省医学科技攻关联合共建项目（LHJG20190569）