Defective mitochondrial fusion, altered respiratory function, and distorted cristae structure in skin fibroblasts with heterozygous OPA1 mutations

BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR BASIS OF DISEASE

卷:1822

Article

Agier, Virginie¹  Oliviero, Patricia¹  Laine, Jeanne²  L'Hermitte-Stead, Caroline⁴  Girard, Samantha¹  Fillaut, Sandrine³  Jardel, Claude^3,4  Bouillaud, Frederic⁴  Bulteau, Anne Laure⁴  Lombes, Anne^1,3,4 

[1] UPMC, INSERM, UMRS 975, CRICM,CNRS,UMR 7225, F-75013 Paris, France

[2] UPMC, INSERM, UMRS 974, CNRS,UMR 7215, F-75013 Paris, France

[3] CHU Pitie Salpetriere, AP HP, F-75651 Paris, France

[4] Univ Paris 05, INSERM, UMRS 1016, Inst Cochin,CNRS,UMR 8104, F-75014 Paris, France

关键词: Mitochondrial compartment;    Mitochondrial fusion;    Oxidative phosphorylation;    Energy metabolism;    Mitochondrial disease;   

DOI  :  10.1016/j.bbadis.2012.07.002

来源: Elsevier

【 摘 要 】

Deleterious consequences of heterozygous OPA1 mutations responsible for autosomal dominant optic atrophy remain a matter of debate. Primary skin fibroblasts derived from patients have shown diverse mitochondrial alterations that were however difficult to resolve in a unifying scheme. To address the potential use of these cells as disease model, we undertook parallel and quantitative analyses of the diverse reported alterations in four fibroblast lines harboring different OPA1 mutations, nonsense or missense, in the guanosine triphosphatase or the C-terminal coiled-coil domains. We tackled several factors potentially underlying discordant reports and showed that fibroblasts with heterozygous OPA1 mutations present with several mitochondrial alterations. These included defective mitochondrial fusion during pharmacological challenge with the protonophore carbonyl cyanide m-chlorophenyl hydrazone, significant mitochondrial elongation with decreased OPA1 and DRP1 proteins, and abnormal mitochondrial fragmentation during glycolysis short-age or exogenous oxidative stress. Respiratory complex IV activity and subunits steady-state were decreased without alteration of the mitochondrial deoxyribonucleic acid size, amount or transcription. Physical link between OPA1 protein and oxidative phosphorylation was shown by reciprocal immunoprecipitation. Altered cristae structure coexisted with normal response to pro-apoptotic stimuli and expression of Bax or BcI2 proteins. Skin fibroblasts with heterozygous OPA1 mutations thus share significant mitochondrial remodeling, and may therefore be useful for analyzing disease pathophysiology. Identifying whether the observed alterations are also present in ganglion retinal cells, and which of them underlies their degeneration process remains however an essential goal for therapeutic strategy. (C) 2012 Elsevier B.V. All rights reserved.

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