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Type: Artigo de periódico
Title: Mitochondrial Permeability Transition In Neuronal Damage Promoted By Ca2+ And Respiratory Chain Complex Ii Inhibition.
Author: Maciel, Evelise N
Kowaltowski, Alicia J
Schwalm, Fábio D
Rodrigues, Juliana M
Souza, Diogo O
Vercesi, Anibal E
Wajner, Moacir
Castilho, Roger F
Abstract: Changes in mitochondrial integrity, reactive oxygen species release and Ca2+ handling are proposed to be involved in the pathogenesis of many neurological disorders including methylmalonic acidaemia and Huntington's disease, which exhibit partial mitochondrial respiratory inhibition. In this report, we studied the mechanisms by which the respiratory chain complex II inhibitors malonate, methylmalonate and 3-nitropropionate affect rat brain mitochondrial function and neuronal survival. All three compounds, at concentrations which inhibit respiration by 50%, induced mitochondrial inner membrane permeabilization when in the presence of micromolar Ca2+ concentrations. ADP, cyclosporin A and catalase prevented or delayed this effect, indicating it is mediated by reactive oxygen species and mitochondrial permeability transition (PT). PT induced by malonate was also present in mitochondria isolated from liver and kidney, but required more significant respiratory inhibition. In brain, PT promoted by complex II inhibition was stimulated by increasing Ca2+ cycling and absent when mitochondria were pre-loaded with Ca2+ or when Ca2+ uptake was prevented. In addition to isolated mitochondria, we determined the effect of methylmalonate on cultured PC12 cells and freshly prepared rat brain slices. Methylmalonate promoted cell death in striatal slices and PC12 cells, in a manner attenuated by cyclosporin A and bongkrekate, and unrelated to impairment of energy metabolism. We propose that under conditions in which mitochondrial complex II is partially inhibited in the CNS, neuronal cell death involves the induction of PT.
Subject: Animals
Antimycin A
Bongkrekic Acid
Cell Survival
Dose-response Relationship, Drug
Drug Interactions
Electron Transport Complex Ii
Enzyme Inhibitors
In Vitro Techniques
Membrane Potentials
Methylmalonic Acid
Nitro Compounds
Oxygen Consumption
Pc12 Cells
Tetrazolium Salts
Uncoupling Agents
Citation: Journal Of Neurochemistry. v. 90, n. 5, p. 1025-35, 2004-Sep.
Rights: fechado
Identifier DOI: 10.1111/j.1471-4159.2004.02565.x
Date Issue: 2004
Appears in Collections:Unicamp - Artigos e Outros Documentos

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