Ma Ruixia, Liu Liqiu, Jiang Wei, Yu Yanjuan, Song Haifeng
Department of Nephrology, Affiliated Hospital of Qingdao University Qingdao, China.
Department of Special Medicine, Qingdao University Qingdao, China.
Int J Clin Exp Pathol. 2015 Nov 1;8(11):14063-74. eCollection 2015.
Diabetic nephropathy (DN) is the leading cause of end-stage renal failure, and podocyte injury plays a major role in the development of DN. In this study, we investigated whether tacrolimus (FK506), an immunosuppressor, can attenuate podocyte injury in a type 2 diabetic mellitus (T2DM) rat model with DN. Transmission electron microcopy was used to morphologically evaluate renal injury. The urinary albumin (UAL), creatinine clearance rate (Ccr) and major biochemical parameters, including glucose, insulin, serum creatinine (Scr), urea nitrogen, total cholesterol (CHO) and triglyceride (TG), were examined 12 weeks after the administration of FK506. The expressions of the canonical transient receptor potential 6 (TRPC6), nuclear factor of activated T-cells (NFAT) and nephrin were detected by Western blotting and qPCR. In the rat model of DN, the expressions of TRPC6 and NFAT were significantly elevated compared with the normal rat group; however, the treatment with FK506 normalized the increased expression of TRPC6 and NFAT and attenuated podocyte ultrastructure injury. UAL, Ccr and the biochemical parameters were also improved by the use of FK506. In cell experiments, FK506 improved the decreased expression of nephrin and suppressed the elevated expression of both TRPC6 and NFAT caused by high glucose in accordance with TRPC6 blocker U73122. Our results demonstrated that FK506 could ameliorate podocyte injury in T2DM, which may be related to suppressed expressions of TRPC6 and NFAT.
糖尿病肾病（DN）是终末期肾衰竭的主要原因，足细胞损伤在DN的发展中起主要作用。在本研究中，我们调查了免疫抑制剂他克莫司（FK506）是否能减轻2型糖尿病（T2DM）合并DN大鼠模型中的足细胞损伤。采用透射电子显微镜对肾损伤进行形态学评估。在给予FK506 12周后，检测尿白蛋白（UAL）、肌酐清除率（Ccr）以及包括血糖、胰岛素、血清肌酐（Scr）、尿素氮、总胆固醇（CHO）和甘油三酯（TG）在内的主要生化参数。通过蛋白质免疫印迹法和定量聚合酶链反应检测经典瞬时受体电位6（TRPC6）、活化T细胞核因子（NFAT）和nephrin的表达。在DN大鼠模型中，与正常大鼠组相比，TRPC6和NFAT的表达显著升高；然而，FK506治疗使TRPC6和NFAT的表达增加恢复正常，并减轻了足细胞超微结构损伤。使用FK506还改善了UAL、Ccr和生化参数。在细胞实验中，与TRPC6阻滞剂U73122一致，FK506改善了高糖导致的nephrin表达降低，并抑制了TRPC6和NFAT的表达升高。我们的结果表明，FK506可以改善T2DM中的足细胞损伤，这可能与抑制TRPC6和NFAT的表达有关。
