他克莫司通过稳定细胞骨架和nephrin抑制血管紧张素Ⅱ损伤肾小球足细胞

Tacrolimus inhibits podocyte injury and stabilizes the expression of cytoskeleton and nephrin

目的探讨他克莫司(Tac)在足细胞损伤中的作用机制。方法以血管紧张素Ⅱ(AngⅡ),或AngⅡ联合Tac干预体外培养足细胞,干预后0、12和24 h收集细胞;行荧光染色观察细胞骨架分布,以WB检测足细胞分子nephrin和podocin蛋白表达。结果对照组骨架分子F-actin呈强有力丝状排列,AngⅡ引起F-actin的断裂和不连续分布,Tac明显抑制AngⅡ对F-actin的损坏,维持细胞骨架良好的丝状结构。AngⅡ刺激后24 h,nephrin表达明显低于对照组,Tac抑制AngⅡ对nephrin的下调(1.00±0.19 vs.0.76±0.32,P<0.05),稳定nephrin正常表达;AngⅡ和Tac干预对podocin表达无明显影响。结论 Tac抑制AngⅡ损伤足细胞,稳定细胞骨架的规律排列和nephrin的正常表达。

Objective To investigate the function and molecular mechanism of tacrolimus in podocyte injury and restoration. Methods Cultured podocytes were stimulated by Angiotensin Ⅱ （Ang Ⅱ ） or Ang Ⅱ plus tacrolimus. Cells were collected at different time points （ 0 h, 12 h and 24 h ）. The distribution of F-actin was observed after immunofluorescenee staining, and the protein expression of nephrin and podocin were detected by Western Blot （WB）. Results In normal control podocytes, F-actin was arranged in cytoplasm powerfully. Ang Ⅱ induced the disruption and discontinuity of F-actin. Tacrolimus inhibited the effect of Ang Ⅱ , stabilized the regular arrangement the F-actin. Compared to normal cells, the protein expression of nephrin in Ang Ⅱ group significantly decreased at 24 h after stimulation （0.76 ± 0.32 in Ang Ⅱ group vs. 1.18 ± 0.40 in normal group, P 〈 0.05）. And tacrolimus stabilized the expression of nephrin protein （1.00 ±0.19 in treatment group vs. 0.76 ± 0.32 in Ang Ⅱ group, P 〈 0.05）. Ang Ⅱ and tacrolimus did not affect the expression of podocin protein. Conclusion Tacrolimus inhibits podocyte injury induced by Ang Ⅱ , stabilizes the regular arrangement of cytoskeleton and protein expression of nephrin.