Impact of the mitochondrial genetic background in complex III deficiency.
In recent years clinical evidence has emphasized the importance of the mtDNA genetic background that hosts a primary pathogenic mutation in the clinical expression of mitochondrial disorders, but little experimental confirmation has been provided. We have analyzed the pathogenic role of a novel homo...
| Main Authors: | , , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2010-09-01
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| Series: | PLoS ONE |
| Online Access: | https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/20862300/pdf/?tool=EBI |
| _version_ | 1818005615113404416 |
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| author | Mari Carmen Gil Borlado David Moreno Lastres Maritza Gonzalez Hoyuela Maria Moran Alberto Blazquez Rosa Pello Lorena Marin Buera Toni Gabaldon Juan Jose Garcia Peñas Miguel A Martín Joaquin Arenas Cristina Ugalde |
| author_facet | Mari Carmen Gil Borlado David Moreno Lastres Maritza Gonzalez Hoyuela Maria Moran Alberto Blazquez Rosa Pello Lorena Marin Buera Toni Gabaldon Juan Jose Garcia Peñas Miguel A Martín Joaquin Arenas Cristina Ugalde |
| author_sort | Mari Carmen Gil Borlado |
| collection | DOAJ |
| description | In recent years clinical evidence has emphasized the importance of the mtDNA genetic background that hosts a primary pathogenic mutation in the clinical expression of mitochondrial disorders, but little experimental confirmation has been provided. We have analyzed the pathogenic role of a novel homoplasmic mutation (m.15533 A>G) in the cytochrome b (MT-CYB) gene in a patient presenting with lactic acidosis, seizures, mild mental delay, and behaviour abnormalities. Spectrophotometric analyses of the respiratory chain enzyme activities were performed in different tissues, the whole muscle mitochondrial DNA of the patient was sequenced, and the novel mutation was confirmed by PCR-RFLP. Transmitochondrial cybrids were constructed to confirm the pathogenicity of the mutation, and assembly/stability studies were carried out in fibroblasts and cybrids by means of mitochondrial translation inhibition in combination with blue native gel electrophoresis. Biochemical analyses revealed a decrease in respiratory chain complex III activity in patient's skeletal muscle, and a combined enzyme defect of complexes III and IV in fibroblasts. Mutant transmitochondrial cybrids restored normal enzyme activities and steady-state protein levels, the mutation was mildly conserved along evolution, and the proband's mother and maternal aunt, both clinically unaffected, also harboured the homoplasmic mutation. These data suggested a nuclear genetic origin of the disease. However, by forcing the de novo functioning of the OXPHOS system, a severe delay in the biogenesis of the respiratory chain complexes was observed in the mutants, which demonstrated a direct functional effect of the mitochondrial genetic background. Our results point to possible pitfalls in the detection of pathogenic mitochondrial mutations, and highlight the role of the genetic mtDNA background in the development of mitochondrial disorders. |
| first_indexed | 2024-04-14T04:46:43Z |
| format | Article |
| id | doaj.art-7c6c727f63f149498e750aef37a1f2ea |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-04-14T04:46:43Z |
| publishDate | 2010-09-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS ONE |
| spelling | doaj.art-7c6c727f63f149498e750aef37a1f2ea2022-12-22T02:11:26ZengPublic Library of Science (PLoS)PLoS ONE1932-62032010-09-0159e1280110.1371/journal.pone.0012801Impact of the mitochondrial genetic background in complex III deficiency. Mari Carmen Gil BorladoDavid Moreno LastresMaritza Gonzalez HoyuelaMaria MoranAlberto BlazquezRosa PelloLorena Marin BueraToni GabaldonJuan Jose Garcia PeñasMiguel A MartínJoaquin ArenasCristina UgaldeIn recent years clinical evidence has emphasized the importance of the mtDNA genetic background that hosts a primary pathogenic mutation in the clinical expression of mitochondrial disorders, but little experimental confirmation has been provided. We have analyzed the pathogenic role of a novel homoplasmic mutation (m.15533 A>G) in the cytochrome b (MT-CYB) gene in a patient presenting with lactic acidosis, seizures, mild mental delay, and behaviour abnormalities. Spectrophotometric analyses of the respiratory chain enzyme activities were performed in different tissues, the whole muscle mitochondrial DNA of the patient was sequenced, and the novel mutation was confirmed by PCR-RFLP. Transmitochondrial cybrids were constructed to confirm the pathogenicity of the mutation, and assembly/stability studies were carried out in fibroblasts and cybrids by means of mitochondrial translation inhibition in combination with blue native gel electrophoresis. Biochemical analyses revealed a decrease in respiratory chain complex III activity in patient's skeletal muscle, and a combined enzyme defect of complexes III and IV in fibroblasts. Mutant transmitochondrial cybrids restored normal enzyme activities and steady-state protein levels, the mutation was mildly conserved along evolution, and the proband's mother and maternal aunt, both clinically unaffected, also harboured the homoplasmic mutation. These data suggested a nuclear genetic origin of the disease. However, by forcing the de novo functioning of the OXPHOS system, a severe delay in the biogenesis of the respiratory chain complexes was observed in the mutants, which demonstrated a direct functional effect of the mitochondrial genetic background. Our results point to possible pitfalls in the detection of pathogenic mitochondrial mutations, and highlight the role of the genetic mtDNA background in the development of mitochondrial disorders.https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/20862300/pdf/?tool=EBI |
| spellingShingle | Mari Carmen Gil Borlado David Moreno Lastres Maritza Gonzalez Hoyuela Maria Moran Alberto Blazquez Rosa Pello Lorena Marin Buera Toni Gabaldon Juan Jose Garcia Peñas Miguel A Martín Joaquin Arenas Cristina Ugalde Impact of the mitochondrial genetic background in complex III deficiency. PLoS ONE |
| title | Impact of the mitochondrial genetic background in complex III deficiency. |
| title_full | Impact of the mitochondrial genetic background in complex III deficiency. |
| title_fullStr | Impact of the mitochondrial genetic background in complex III deficiency. |
| title_full_unstemmed | Impact of the mitochondrial genetic background in complex III deficiency. |
| title_short | Impact of the mitochondrial genetic background in complex III deficiency. |
| title_sort | impact of the mitochondrial genetic background in complex iii deficiency |
| url | https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/20862300/pdf/?tool=EBI |
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