title: Cisplatin-induced nephrotoxicity in porcine proximal tubular cells: mitochondrial dysfunction by inhibition of complexes I to IV of the respiratory chain.
abstract: Cisplatin-induced nephrotoxicity was studied in porcine proximal tubular cells, focusing on the relationship between mitochondrial damage, reactive oxygen species (ROS) and cell death. Cisplatin specifically affected mitochondrial functions: complexes I to IV of the respiratory chain were inhibited 15 to 55% after 20 min of incubation with 50 to 500 microM, respectively. As a result, intracellular ATP was decreased to 70%. The mitochondrial glutathione (reduced form) (GSH)-regenerating enzyme GSH-reductase (GSH-Rd) activity was reduced by 20%, which contributed to a 70% reduction of GSH levels and ROS formation. The residual electron flow through the mitochondrial respiratory chain was the source of ROS because additional inhibition of the complexes I to IV reduced ROS formation. Because cisplatin affects both GSH-Rd and complexes I to IV, cells were incubated with N,N'-bis(2-chloroethyl)-N-nitrosourea (inhibitor of GSH-Rd) and inhibitors of the different complexes. Only N,N'-bis(2-chloroethyl)-N-nitrosourea with rotenone (complex I inhibitor) induced ROS formation, which indicates that inhibition of complex I and inhibition of the GSH-Rd is probably the cause of ROS formation. However, the resulting ROS is not the cause of cell death because diphenyl-p-phenylene-diamine and deferoxamine, which completely prevented ROS, could not prevent cell death. Similarly, the antioxidants did not completely prevent the decrease in activity of complexes I to IV, ATP or GSH levels. In conclusion, ROS formation does occur during cisplatin-induced toxicity, but it is not the direct cause of cell death.
authors.affiliation: Division of Toxicology, Leiden/Amsterdam Center for Drug Research, Leiden University, The Netherlands.
authors.forename: M
authors.initials: M
authors.lastname: Kruidering
authors.forename: B
authors.initials: B
authors.lastname: Van de Water
authors.forename: E
authors.initials: E
authors.lastname: de Heer
authors.forename: G J
authors.initials: GJ
authors.lastname: Mulder
authors.forename: J F
authors.initials: JF
authors.lastname: Nagelkerke
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D000970:Antineoplastic Agents / Q000633:toxicity*; D002330:Carmustine / Q000494:pharmacology; D002470:Cell Survival / Q000187:drug effects; D002945:Cisplatin / Q000633:toxicity*; D003676:Deferoxamine / Q000494:pharmacology; D042963:Electron Transport Complex II; D014450:Electron Transport Complex III / Q000037:antagonists & inhibitors; D003576:Electron Transport Complex IV / Q000037:antagonists & inhibitors; D005978:Glutathione / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D007687:Kidney Tubules, Proximal / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D007700:Kinetics; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism*; D009097:Multienzyme Complexes / Q000037:antagonists & inhibitors; D016660:NAD(P)H Dehydrogenase (Quinone) / Q000037:antagonists & inhibitors; D010088:Oxidoreductases / Q000037:antagonists & inhibitors; D010101:Oxygen Consumption / Q000187:drug effects*; D010655:Phenylenediamines / Q000494:pharmacology; D017382:Reactive Oxygen Species / Q000378:metabolism; D012402:Rotenone / Q000494:pharmacology; D013385:Succinate Dehydrogenase / Q000037:antagonists & inhibitors; D013552:Swine
chemical_list: D000970:Antineoplastic Agents; D009097:Multienzyme Complexes; D010655:Phenylenediamines; D017382:Reactive Oxygen Species; D012402:Rotenone; D000255:Adenosine Triphosphate; D010088:Oxidoreductases; D042963:Electron Transport Complex II; D013385:Succinate Dehydrogenase; D016660:NAD(P)H Dehydrogenase (Quinone); D005980:Glutathione Reductase; D003576:Electron Transport Complex IV; D014450:Electron Transport Complex III; D005978:Glutathione; D003676:Deferoxamine; D002945:Cisplatin; D002330:Carmustine; C029728:4-phenylenediamine