• Wan-Xin Tang, Wei-Hua Wu, Hong-Yu Qiu, Hong Bo, and Song-Min Huang.
• Division of Nephrology, West China Hospital of Sichuan University, Chengdu, Sichuan - PR China.
• J. Nephrol. 2013 Nov 1;26(6):1073-82.

IntroductionMitochondrial dysfunction plays an important role in acute kidney injury (AKI). Mitochondrial fission regulated by dynamin-related protein 1 (Drp-1) impairs the function of the mitochondria and the survival of cells. This study was conducted to explore the effects of suppression of Drp-1 accumulation in the mitochondria, on mitochondrial function and renal tubular cell apoptosis in rhabdomyolysis (RM)-induced AKI.MethodsAn RM model was induced by intramuscular injection of glycerol in Sprague Dawley rats. Twenty-four and 48 hours after intraperitoneal injections of mitochondrial division inhibitor 1 (Mdivi-1), we observed the functions of the kidney, changes in pathology, expressions of Drp-1 in tubular tissues (by immunohistochemistry and Western blot) and accumulation of Drp-1 and mitofusin 2 in tubular mitochondria (by Western blot). Mitochondrial function (ATP and ROS) and tubular epithelial cell apoptosis (by TUNEL) were also measured.ResultsRM induced Drp-1 accumulation, decreased ATP production and increased ROS in mitochondria. With increasing cytochrome c expression, cell apoptosis increased, whereas kidney function decreased. These changes were time-dependent. At different time points, despite not significantly influencing the overall expression of Drp-1, Mdivi-1 suppressed the accumulation of Drp-1, inhibited the insertion of proapoptotic Bax in mitochondria and inhibited the release of cytochrome c, thus ameliorating cell apoptosis.ConclusionsTo conclude, in RM-induced AKI, suppression of Drp-1 accumulation in mitochondria favors the maintenance of mitochondrial function and reduces the apoptosis of tubular cells. Regulation of the mitochondrial fusion-fission balance may offer a novel strategy for the prevention and treatment of RM-induced AKI.

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