氧化苦参碱抑制高糖诱导的大鼠肾小管上皮-间充质转化及其机制研究

 目的：探讨氧化苦参碱(OM)对高糖诱导的大鼠肾小管上皮-间充质转化（EMT）的抑制作用及其可能机制。方法：体外培养大鼠近端肾小管上皮NRK52E细胞，随机分为：对照组、高糖组、高糖+OM不同浓度组和高糖+0.50 g/L OM动态观察组。采用real-time PCR和Western blotting方法检测转化生长因子β1（TGF-β1）、Smad7、α-平滑肌肌动蛋白（α-SMA）、E-钙黏素（E-cadherin）mRNA和蛋白的表达。结果：（1）与对照组相比，高糖组TGF-β1、α-SMA mRNA和蛋白表达水平均进行性增高，Smad7蛋白表达进行性降低，E-cadherin mRNA和蛋白表达进行性降低，呈时间依赖性（P＜0.05），而Smad7 mRNA表达进行性增高（P＜0.05）；（2）与高糖组相比，高糖+ OM不同浓度组随OM剂量增加，TGF-β1、α-SMA mRNA和蛋白表达均逐渐降低，Smad7蛋白表达水平逐渐增高，E-cadherin mRNA和蛋白表达水平逐渐增高，且呈剂量依赖性（P＜0.05），而Smad7 mRNA表达无明显差异；（3）与高糖组相比，高糖+0.50 g/L OM动态观察组TGF-β1、α-SMA mRNA和蛋白表达持续降低，Smad7蛋白表达持续增高，E-cadherin mRNA和蛋白表达持续增高（P＜0.05），而Smad7 mRNA表达无明显差异。结论：OM可抑制高糖诱导的NRK52E细胞发生EMT，其机制可能与OM下调TGF-β1表达及上调Smad7蛋白表达，进而抑制TGF-β1/Smads信号通路的致纤维化效应有关。

Inhibitory effect of oxymatrine on high glucose-induced rat renal tubular epithelial-mesenchymal transition

AIM:To investigate the inhibitory effect of oxymatrine (OM) on high glucose-induced rat renal tubular epithelial-mesenchymal transition (EMT). METHODS:The rat renal tubular epithelial NRK52E cells were cultured in vitro. The cells were divided into control group, high glucose group, high glucose+different concentrations of OM groups and high glucose+0.50 g/L OM dynamic observation group. The expression of TGF-β1, Smad7, α-SMA and E-cadherin at mRNA and protein levels was detected by real-time PCR and Western blotting. The viability of NRK52E cells was determined by MTT assay. RESULTS:(1) Compared with control group, the expression of TGF-β1 and α-SMA at mRNA and protein levels in high glucose group gradually increased, and Smad7 protein and E-cadherin mRNA and protein gradually reduced, but the mRNA expression of Smad7 gradually increased. (2) Compared with high glucose group, as increases in OM doses, the expression of TGF-β1 and α-SMA at mRNA and protein levels in high glucose+different concentrations of OM groups gradually reduced, and Smad7 protein and E-cadherin mRNA and protein gradually increased, but the mRNA expression of Smad7 had no significant change. (3) Compared with high glucose group, the expression of TGF-β1 and α-SMA at mRNA and protein levels was significantly reduced, the expression of E-cadherin at mRNA and protein levels significantly increased, and the protein expression of Smad7 significantly increased, but the mRNA expression of Smad7 had no significant change in high glucose+0.50 g/L OM dynamic observation group. CONCLUSION: In NRK52E cells, oxymatrine inhibits high glucose induced EMT by down-regulating TGF-β1 and up-regulating Smad7, thus preventing the fibrosis effect of TGF-β1/Smads signaling.