Barth syndrome cells display widespread remodeling of mitochondrial complexes without affecting metabolic flux distribution.
Biochim Biophys Acta Mol Basis Dis
; 1864(11): 3650-3658, 2018 11.
Article
em En
| MEDLINE
| ID: mdl-30251684
Barth syndrome (BTHS) is a rare X-linked disorder that is characterized by cardiac and skeletal myopathy, neutropenia and growth abnormalities. The disease is caused by mutations in the tafazzin (TAZ) gene encoding an enzyme involved in the acyl chain remodeling of the mitochondrial phospholipid cardiolipin (CL). Biochemically, this leads to decreased levels of mature CL and accumulation of the intermediate monolysocardiolipin (MLCL). At a cellular level, this causes mitochondrial fragmentation and reduced stability of the respiratory chain supercomplexes. However, the exact mechanism through which tafazzin deficiency leads to disease development remains unclear. We therefore aimed to elucidate the pathways affected in BTHS cells by employing proteomic and metabolic profiling assays. Complexome profiling of patient skin fibroblasts revealed significant effects for about 200 different mitochondrial proteins. Prominently, we found a specific destabilization of higher order oxidative phosphorylation (OXPHOS) supercomplexes, as well as changes in complexes involved in cristae organization and CL trafficking. Moreover, the key metabolic complexes 2-oxoglutarate dehydrogenase (OGDH) and branched-chain ketoacid dehydrogenase (BCKD) were profoundly destabilized in BTHS patient samples. Surprisingly, metabolic flux distribution assays using stable isotope tracer-based metabolomics did not show reduced flux through the TCA cycle. Overall, insights from analyzing the impact of TAZ mutations on the mitochondrial complexome provided a better understanding of the resulting functional and structural consequences and thus the pathological mechanisms leading to Barth syndrome.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fatores de Transcrição
/
Transdução de Sinais
/
Membranas Mitocondriais
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Redes e Vias Metabólicas
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Síndrome de Barth
Tipo de estudo:
Observational_studies
Limite:
Humans
Idioma:
En
Revista:
Biochim Biophys Acta Mol Basis Dis
Ano de publicação:
2018
Tipo de documento:
Article