Novel effect of the inhibitor of mitochondrial cyclophilin D activation, N-methyl-4-isoleucine cyclosporin, on renal calcium crystallization

• Published in: International journal of urology Vol. 21; no. 7; pp. 707 - 713
• Main Authors: Niimi, Kazuhiro, Yasui, Takahiro, Okada, Atsushi, Hirose, Yasuhiko, Kubota, Yasue, Umemoto, Yukihiro, Kawai, Noriyasu, Tozawa, Keiichi, Kohri, Kenjiro
• Format: Journal Article
• Language: English
• Published: Australia Blackwell Publishing Ltd 01.07.2014
• Subjects: Animals; Apoptosis - drug effects; Calcium Oxalate - chemistry; Calcium Oxalate - pharmacology; Cell Line; Cyclophilins - antagonists & inhibitors; Cyclophilins - metabolism; cyclophilin D; Cyclosporine - chemistry; Cyclosporine - pharmacology; Enzyme Inhibitors - chemistry; Enzyme Inhibitors - pharmacology; Hyperoxaluria - drug therapy; Hyperoxaluria - metabolism; Kidney Tubules, Proximal - cytology; Kidney Tubules, Proximal - metabolism; Kidney Tubules, Proximal - ultrastructure; Male; Membrane Potential, Mitochondrial - drug effects; Microscopy, Electron, Transmission; Mitochondria - drug effects; Mitochondria - metabolism; Mitochondria - ultrastructure; N-methyl-4-isoleucine cyclosporin; oxidative stress; Oxidative Stress - drug effects; Peptidyl-Prolyl Isomerase F; Rats, Sprague-Dawley; renal calcium crystallization; renal tubular cell injury; cyclophilin D; renal tubular cell injury; N-methyl-4-isoleucine cyclosporin; oxidative stress; renal calcium crystallization
• ISSN: 0919-8172; 1442-2042
• DOI: 10.1111/iju.12425

Objectives To experimentally evaluate the clinical application of N‐methyl‐4‐isoleucine cyclosporin, a novel selective inhibitor of cyclophilin D activation. Methods In vitro, cultured renal tubular cells were exposed to calcium oxalate monohydrate crystals and treated with N‐methyl‐4‐isoleucine cyclosporin. The mitochondrial membrane was stained with tetramethylrhodamine ethyl ester perchlorate and observed. In vivo, Sprague–Dawley rats were divided into four groups: a control group, an ethylene glycol group (administration of ethylene glycol to induce renal calcium crystallization), a N‐methyl‐4‐isoleucine cyclosporin group (administration of N‐methyl‐4‐isoleucine cyclosporin) and an ethylene glycol + N‐methyl‐4‐isoleucine cyclosporin group (administration of ethylene glycol and N‐methyl‐4‐isoleucine cyclosporin). Renal calcium crystallization was evaluated using Pizzolato staining. Oxidative stress was evaluated using superoxide dismutase and 8‐hydroxy‐deoxyguanosine. Mitochondria within renal tubular cells were observed by transmission electron microscopy. Cell apoptosis was evaluated using cleaved caspase‐3. Results In vitro, calcium oxalate monohydrate crystals induced depolarization of the mitochondrial membrane potential, which was remarkably prevented by N‐methyl‐4‐isoleucine cyclosporin. In vivo, ethylene glycol administration induced renal calcium crystallization, oxidative stress, mitochondrial collapse and cell apoptosis in rats, which were significantly prevented by N‐methyl‐4‐isoleucine cyclosporin. Conclusions Herein we first report a new treatment agent determining renal calcium crystallization through cyclophilin D activation.