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Alila-Fersi O, Tej A, Maalej M, Kharrat M, Boughamoura L, Chouchen J, Tlili A, Fakhfakh F. Mitochondrial genes modulate the phenotypic expression of congenital scoliosis syndrome caused by mutations in the TBXT gene. Gene 2024; 914:148388. [PMID: 38499212 DOI: 10.1016/j.gene.2024.148388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2024] [Revised: 02/29/2024] [Accepted: 03/15/2024] [Indexed: 03/20/2024]
Abstract
BACKGROUND Congenital scoliosis (CS) is a spinal disorder caused by genetic-congenital vertebral malformations and may be associated with other congenital defects or may occur alone. It is genetically heterogeneous and numerous genes contributing to this disease have been identified. In addition, CS has a wide range of phenotypic and genotypic variability, which has been explained by the intervention of genetic factors like modifiers and environment genes. The aim of the present study was to determine the possible cause of CS in a Tunisian patient and to examine the association between mtDNA mutations and mtDNA content and CS. METHODS Here we performed Whole-Exome Sequencing (WES) in a patient presenting clinical features suggestive of severe congenital scoliosis syndrome. Direct sequencing of the whole mitochondrial DNA (mtDNA) was also performed in addition to copy number quantification in the blood of the indexed case. In silico prediction tools, 3D modeling and molecular docking approaches were used. RESULTS The WES revealed the homozygous missense mutation c.512A > G (p.H171R) in the TBXT gene. Bioinformatic analysis demonstrated that the p.H171R variant was highly deleterious and caused the TBXT structure instability. Molecular docking revealed that the p.H171R mutation disrupted the monomer stability which seemed to be crucial for maintaining the stability of the homodimer and consequently to the destabilization of the homodimer-DNA complex. On the other hand, we hypothesized that mtDNA can be a modifier factor, so, the screening of the whole mtDNA showed a novel heteroplasmic m.10150T > A (p.M31K) variation in the MT-ND3 gene. Further, qPCR analyses of the patient's blood excluded mtDNA depletion. Bioinformatic investigation revealed that the p.M31K mutation in the ND3 protein was highly deleterious and may cause the ND3 protein structure destabilization and could disturb the interaction between complex I subunits. CONCLUSION We described the possible role of mtDNA genetics on the pathogenesis of congenital scoliosis by hypothesizing that the presence of the homozygous variant in TBXT accounts for the CS phenotype in our patient and the MT-ND3 gene may act as a modifier gene.
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Affiliation(s)
- Olfa Alila-Fersi
- Molecular Genetics and Functional Laboratory, Faculty of Science of Sfax, University of Sfax, Sfax 3000, Tunisia.
| | - Amel Tej
- Department of Pediatrics, University Hospital Farhat Hached, Sousse, Tunisia
| | - Marwa Maalej
- Molecular Genetics and Functional Laboratory, Faculty of Science of Sfax, University of Sfax, Sfax 3000, Tunisia
| | - Marwa Kharrat
- Molecular Genetics and Functional Laboratory, Faculty of Science of Sfax, University of Sfax, Sfax 3000, Tunisia
| | - Lamia Boughamoura
- Department of Pediatrics, University Hospital Farhat Hached, Sousse, Tunisia
| | - Jihen Chouchen
- Molecular Genetics and Stem Cell Research Laboratory, University of Sharjah, Sharjah, United Arab Emirates
| | - Abdelaziz Tlili
- Human Genetics and Stem Cell Research Group, Research Institute of Sciences and Engineering, University of Sharjah, Sharjah, United Arab Emirates
| | - Faiza Fakhfakh
- Molecular Genetics and Functional Laboratory, Faculty of Science of Sfax, University of Sfax, Sfax 3000, Tunisia.
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2
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Baldo MS, Nogueira C, Pereira C, Janeiro P, Ferreira S, Lourenço CM, Bandeira A, Martins E, Magalhães M, Rodrigues E, Santos H, Ferreira AC, Vilarinho L. Leigh Syndrome Spectrum: A Portuguese Population Cohort in an Evolutionary Genetic Era. Genes (Basel) 2023; 14:1536. [PMID: 37628588 PMCID: PMC10454233 DOI: 10.3390/genes14081536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 07/21/2023] [Accepted: 07/24/2023] [Indexed: 08/27/2023] Open
Abstract
Mitochondrial diseases are the most common inherited inborn error of metabolism resulting in deficient ATP generation, due to failure in homeostasis and proper bioenergetics. The most frequent mitochondrial disease manifestation in children is Leigh syndrome (LS), encompassing clinical, neuroradiological, biochemical, and molecular features. It typically affects infants but occurs anytime in life. Considering recent updates, LS clinical presentation has been stretched, and is now named LS spectrum (LSS), including classical LS and Leigh-like presentations. Apart from clinical diagnosis challenges, the molecular characterization also progressed from Sanger techniques to NGS (next-generation sequencing), encompassing analysis of nuclear (nDNA) and mitochondrial DNA (mtDNA). This upgrade resumed steps and favored diagnosis. Hereby, our paper presents molecular and clinical data on a Portuguese cohort of 40 positive cases of LSS. A total of 28 patients presented mutation in mtDNA and 12 in nDNA, with novel mutations identified in a heterogeneous group of genes. The present results contribute to the better knowledge of the molecular basis of LS and expand the clinical spectrum associated with this syndrome.
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Affiliation(s)
- Manuela Schubert Baldo
- Research and Development Unit, Human Genetics Department, National Institute of Health Doutor Ricardo Jorge, 4000-055 Porto, Portugal; (M.S.B.)
| | - Célia Nogueira
- Research and Development Unit, Human Genetics Department, National Institute of Health Doutor Ricardo Jorge, 4000-055 Porto, Portugal; (M.S.B.)
- Neonatal Screening, Metabolism and Genetics Unit, Human Genetics Department, National Institute of Health Doutor Ricardo Jorge, 4000-055 Porto, Portugal
| | - Cristina Pereira
- Research and Development Unit, Human Genetics Department, National Institute of Health Doutor Ricardo Jorge, 4000-055 Porto, Portugal; (M.S.B.)
- Neonatal Screening, Metabolism and Genetics Unit, Human Genetics Department, National Institute of Health Doutor Ricardo Jorge, 4000-055 Porto, Portugal
| | - Patrícia Janeiro
- Inherited Metabolic Disease Reference Center, Lisbon North University Hospital Center (CHULN), EPE, 1649-028 Lisbon, Portugal
| | - Sara Ferreira
- Inherited Metabolic Disease Reference Center, Pediatric Hospital, Hospital and University Center of Coimbra, 3004-561 Coimbra, Portugal
| | - Charles M. Lourenço
- Neurogenetics Department, Faculdade de Medicina de São Jose do Rio Preto, São Jose do Rio Preto 15090-000, Brazil
| | - Anabela Bandeira
- Oporto Hospital Centre, University of Porto, 4099-001 Porto, Portugal
| | - Esmeralda Martins
- Oporto Hospital Centre, University of Porto, 4099-001 Porto, Portugal
- Unit for Multidisciplinary Research in Biomedicine, Instituto de Ciências Biomédicas Abel Salazar, Porto University, 4050-313 Porto, Portugal
| | - Marina Magalhães
- Department of Neurology Porto Hospital and University Centre, EPE, 4050-011 Porto, Portugal
| | - Esmeralda Rodrigues
- Reference Center for Inherited Metabolic Disorders, University Hospital Centre S. João, 4200-319 Porto, Portugal
| | - Helena Santos
- Department of Pediatrics, Hospital Centre, EPE, 4434-502 Vila Nova de Gaia, Portugal
| | | | - Laura Vilarinho
- Research and Development Unit, Human Genetics Department, National Institute of Health Doutor Ricardo Jorge, 4000-055 Porto, Portugal; (M.S.B.)
- Neonatal Screening, Metabolism and Genetics Unit, Human Genetics Department, National Institute of Health Doutor Ricardo Jorge, 4000-055 Porto, Portugal
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3
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Laube E, Meier-Credo J, Langer JD, Kühlbrandt W. Conformational changes in mitochondrial complex I of the thermophilic eukaryote Chaetomium thermophilum. SCIENCE ADVANCES 2022; 8:eadc9952. [PMID: 36427319 PMCID: PMC9699679 DOI: 10.1126/sciadv.adc9952] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 10/07/2022] [Indexed: 05/23/2023]
Abstract
Mitochondrial complex I is a redox-driven proton pump that generates proton-motive force across the inner mitochondrial membrane, powering oxidative phosphorylation and ATP synthesis in eukaryotes. We report the structure of complex I from the thermophilic fungus Chaetomium thermophilum, determined by cryoEM up to 2.4-Å resolution. We show that the complex undergoes a transition between two conformations, which we refer to as state 1 and state 2. The conformational switch is manifest in a twisting movement of the peripheral arm relative to the membrane arm, but most notably in substantial rearrangements of the Q-binding cavity and the E-channel, resulting in a continuous aqueous passage from the E-channel to subunit ND5 at the far end of the membrane arm. The conformational changes in the complex interior resemble those reported for mammalian complex I, suggesting a highly conserved, universal mechanism of coupling electron transport to proton pumping.
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Affiliation(s)
- Eike Laube
- Max-Planck-Institute of Biophysics, Frankfurt 60438, Germany
| | - Jakob Meier-Credo
- Max-Planck-Institute of Biophysics, Frankfurt 60438, Germany
- Max-Planck-Institute for Brain Research, Frankfurt 60438, Germany
| | - Julian D. Langer
- Max-Planck-Institute of Biophysics, Frankfurt 60438, Germany
- Max-Planck-Institute for Brain Research, Frankfurt 60438, Germany
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4
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Newstead SM, Finsterer J. Leigh-Like Syndrome With a Novel, Complex Phenotype Due to m.10191T>C in Mt-ND3. Cureus 2022; 14:e28986. [PMID: 36249637 PMCID: PMC9548404 DOI: 10.7759/cureus.28986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/09/2022] [Indexed: 11/24/2022] Open
Abstract
Leigh-like syndrome (LLS) due to the variant m.10191T>C in ND3 with a number of new phenotypic traits has not been published. In this case report, a 32-year-old woman diagnosed with Leigh-like syndrome presented with a complex novel, progressive, multisystem phenotype, manifesting in the brain (mild cognitive impairment, seizures, choreoathetosis, pseudotumor cerebri, hypersomnia, symmetric pallidal hypointensities, panda sign, calcifications, dysphagia), endocrine organs (empty sella syndrome, hypocorticism, hypoaldosteronism, hypogonadism), hematopoietic system (anemia, lymphocytosis), immune system (lymphocytosis, hypogammaglobulinemia), gut (reflux, diarrhea), kidneys (renal insufficiency, renal tubular acidosis, nephrolithiasis), muscles (myopathy, exercise intolerance, easy fatigability), peripheral nerves (small fiber neuropathy, dysautonomia), connective tissue (hyperlaxity of joints, bruising), and bones (scoliosis, Chiari malformation). A genetic workup revealed the known pathogenic variant m.10191T>C in ND3, which was also carried by the patient’s mother. This case demonstrates that the m.10191T>C variant in ND3 can phenotypically manifest with multisystem disease and that this disease is responsive to symptomatic treatment and application of additional compounds.
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Han ZZ, Kang SG, Arce L, Westaway D. Prion-like strain effects in tauopathies. Cell Tissue Res 2022; 392:179-199. [PMID: 35460367 PMCID: PMC9034081 DOI: 10.1007/s00441-022-03620-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 03/25/2022] [Indexed: 12/30/2022]
Abstract
Tau is a microtubule-associated protein that plays crucial roles in physiology and pathophysiology. In the realm of dementia, tau protein misfolding is associated with a wide spectrum of clinicopathologically diverse neurodegenerative diseases, collectively known as tauopathies. As proposed by the tau strain hypothesis, the intrinsic heterogeneity of tauopathies may be explained by the existence of structurally distinct tau conformers, “strains”. Tau strains can differ in their associated clinical features, neuropathological profiles, and biochemical signatures. Although prior research into infectious prion proteins offers valuable lessons for studying how a protein-only pathogen can encompass strain diversity, the underlying mechanism by which tau subtypes are generated remains poorly understood. Here we summarize recent advances in understanding different tau conformers through in vivo and in vitro experimental paradigms, and the implications of heterogeneity of pathological tau species for drug development.
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Affiliation(s)
- Zhuang Zhuang Han
- Centre for Prions and Protein Folding Diseases, University of Alberta, 204 Brain and Aging Research Building, Edmonton, AB, T6G 2M8, Canada.,Department of Medicine, University of Alberta, Edmonton, AB, Canada.,Department of Biochemistry, University of Alberta, Edmonton, AB, Canada
| | - Sang-Gyun Kang
- Centre for Prions and Protein Folding Diseases, University of Alberta, 204 Brain and Aging Research Building, Edmonton, AB, T6G 2M8, Canada.,Department of Medicine, University of Alberta, Edmonton, AB, Canada
| | - Luis Arce
- Centre for Prions and Protein Folding Diseases, University of Alberta, 204 Brain and Aging Research Building, Edmonton, AB, T6G 2M8, Canada.,Department of Medicine, University of Alberta, Edmonton, AB, Canada.,Department of Biochemistry, University of Alberta, Edmonton, AB, Canada
| | - David Westaway
- Centre for Prions and Protein Folding Diseases, University of Alberta, 204 Brain and Aging Research Building, Edmonton, AB, T6G 2M8, Canada. .,Department of Medicine, University of Alberta, Edmonton, AB, Canada. .,Department of Biochemistry, University of Alberta, Edmonton, AB, Canada.
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6
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Zhang F, Dang QCL, Vik SB. Human clinical mutations in mitochondrially encoded subunits of Complex I can be successfully modeled in E. coli. Mitochondrion 2022; 64:59-72. [PMID: 35306226 PMCID: PMC9035099 DOI: 10.1016/j.mito.2022.03.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 02/21/2022] [Accepted: 03/15/2022] [Indexed: 11/28/2022]
Abstract
Respiratory Complex I is the site of a large fraction of the mutations that appear to cause mitochondrial disease. Seven of its subunits are mitochondrially encoded, and therefore, such mutants are particularly difficult to construct in cell-culture model systems. We have selected 13 human clinical mutations found in ND2, ND3, ND4, ND4L, ND5 and ND6 that are generally found at subunit interfaces, and not in critical residues. These mutations have been modeled in E. coli subunits of Complex I, nuoN, nuoA, nuoM, nuoK, nuoL, and nuoJ, respectively. All mutants were expressed from a plasmid encoding the entire nuo operon, and membrane vesicles were analyzed for deamino-NADH oxidase activity, and proton translocation activity. ND5 mutants were also analyzed using a time-delayed expression system, recently described by this lab. Other mutants were analyzed for the ability to associate in subcomplexes, after expression of subsets of the genes. For most mutants there was a positive correlation between those that were previously determined to be pathogenic, or likely to be pathogenic, and those that we found with compromised Complex I activity or subunit interactions in E. coli. In conclusion, this approach provides another way to explore the deleterious effects of human mitochondrial mutations, and it can contribute to molecular understanding of such mutations.
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Affiliation(s)
- Fang Zhang
- Department of Biological Sciences, Southern Methodist University, Dallas, TX 75275-0376, USA
| | - Quynh-Chi L Dang
- Department of Biological Sciences, Southern Methodist University, Dallas, TX 75275-0376, USA
| | - Steven B Vik
- Department of Biological Sciences, Southern Methodist University, Dallas, TX 75275-0376, USA.
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7
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Bakare AB, Lesnefsky EJ, Iyer S. Leigh Syndrome: A Tale of Two Genomes. Front Physiol 2021; 12:693734. [PMID: 34456746 PMCID: PMC8385445 DOI: 10.3389/fphys.2021.693734] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Accepted: 07/22/2021] [Indexed: 12/21/2022] Open
Abstract
Leigh syndrome is a rare, complex, and incurable early onset (typically infant or early childhood) mitochondrial disorder with both phenotypic and genetic heterogeneity. The heterogeneous nature of this disorder, based in part on the complexity of mitochondrial genetics, and the significant interactions between the nuclear and mitochondrial genomes has made it particularly challenging to research and develop therapies. This review article discusses some of the advances that have been made in the field to date. While the prognosis is poor with no current substantial treatment options, multiple studies are underway to understand the etiology, pathogenesis, and pathophysiology of Leigh syndrome. With advances in available research tools leading to a better understanding of the mitochondria in health and disease, there is hope for novel treatment options in the future.
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Affiliation(s)
- Ajibola B. Bakare
- Department of Biological Sciences, J. William Fulbright College of Arts and Sciences, University of Arkansas, Fayetteville, AR, United States
| | - Edward J. Lesnefsky
- Division of Cardiology, Pauley Heart Center, Department of Internal Medicine, School of Medicine, Virginia Commonwealth University, Richmond, VA, United States
- Department of Physiology/Biophysics, School of Medicine, Virginia Commonwealth University, Richmond, VA, United States
- Department of Biochemistry and Molecular Biology, School of Medicine, Virginia Commonwealth University, Richmond, VA, United States
| | - Shilpa Iyer
- Department of Biological Sciences, J. William Fulbright College of Arts and Sciences, University of Arkansas, Fayetteville, AR, United States
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8
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Blackout in the powerhouse: clinical phenotypes associated with defects in the assembly of OXPHOS complexes and the mitoribosome. Biochem J 2021; 477:4085-4132. [PMID: 33151299 PMCID: PMC7657662 DOI: 10.1042/bcj20190767] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 09/29/2020] [Accepted: 10/05/2020] [Indexed: 12/26/2022]
Abstract
Mitochondria produce the bulk of the energy used by almost all eukaryotic cells through oxidative phosphorylation (OXPHOS) which occurs on the four complexes of the respiratory chain and the F1–F0 ATPase. Mitochondrial diseases are a heterogenous group of conditions affecting OXPHOS, either directly through mutation of genes encoding subunits of OXPHOS complexes, or indirectly through mutations in genes encoding proteins supporting this process. These include proteins that promote assembly of the OXPHOS complexes, the post-translational modification of subunits, insertion of cofactors or indeed subunit synthesis. The latter is important for all 13 of the proteins encoded by human mitochondrial DNA, which are synthesised on mitochondrial ribosomes. Together the five OXPHOS complexes and the mitochondrial ribosome are comprised of more than 160 subunits and many more proteins support their biogenesis. Mutations in both nuclear and mitochondrial genes encoding these proteins have been reported to cause mitochondrial disease, many leading to defective complex assembly with the severity of the assembly defect reflecting the severity of the disease. This review aims to act as an interface between the clinical and basic research underpinning our knowledge of OXPHOS complex and ribosome assembly, and the dysfunction of this process in mitochondrial disease.
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9
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Fernandez-Vizarra E, Zeviani M. Mitochondrial disorders of the OXPHOS system. FEBS Lett 2020; 595:1062-1106. [PMID: 33159691 DOI: 10.1002/1873-3468.13995] [Citation(s) in RCA: 99] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Revised: 10/21/2020] [Accepted: 11/01/2020] [Indexed: 12/13/2022]
Abstract
Mitochondrial disorders are among the most frequent inborn errors of metabolism, their primary cause being the dysfunction of the oxidative phosphorylation system (OXPHOS). OXPHOS is composed of the electron transport chain (ETC), formed by four multimeric enzymes and two mobile electron carriers, plus an ATP synthase [also called complex V (cV)]. The ETC performs the redox reactions involved in cellular respiration while generating the proton motive force used by cV to synthesize ATP. OXPHOS biogenesis involves multiple steps, starting from the expression of genes encoded in physically separated genomes, namely the mitochondrial and nuclear DNA, to the coordinated assembly of components and cofactors building each individual complex and eventually the supercomplexes. The genetic cause underlying around half of the diagnosed mitochondrial disease cases is currently known. Many of these cases result from pathogenic variants in genes encoding structural subunits or additional factors directly involved in the assembly of the ETC complexes. Here, we review the historical and most recent findings concerning the clinical phenotypes and the molecular pathological mechanisms underlying this particular group of disorders.
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Affiliation(s)
- Erika Fernandez-Vizarra
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, UK
| | - Massimo Zeviani
- Venetian Institute of Molecular Medicine, Padova, Italy.,Department of Neurosciences, University of Padova, Italy
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10
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Naeem MM, Maheshan R, Costford SR, Wahedi A, Trajkovski M, Plavec J, Yatsunyk LA, Ciesielski GL, Kaufman BA, Sondheimer N. G-quadruplex-mediated reduction of a pathogenic mitochondrial heteroplasmy. Hum Mol Genet 2020; 28:3163-3174. [PMID: 31261379 DOI: 10.1093/hmg/ddz153] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 05/28/2019] [Accepted: 06/21/2019] [Indexed: 12/18/2022] Open
Abstract
Disease-associated variants in mitochondrial DNA (mtDNA) are frequently heteroplasmic, a state of co-existence with the wild-type genome. Because heteroplasmy correlates with the severity and penetrance of disease, improvement in the ratio between these genomes in favor of the wild-type, known as heteroplasmy shifting, is potentially therapeutic. We evaluated known pathogenic mtDNA variants and identified those with the potential for allele-specific differences in the formation of non-Watson-Crick G-quadruplex (GQ) structures. We found that the Leigh syndrome (LS)-associated m.10191C variant promotes GQ formation within local sequence in vitro. Interaction of this sequence with a small molecule GQ-binding agent, berberine hydrochloride, further increased GQ stability. The GQ formed at m.10191C differentially impeded the processivity of the mitochondrial DNA polymerase gamma (Pol γ) in vitro, providing a potential means to favor replication of the wild-type allele. We tested the potential for shifting heteroplasmy through the cyclical application of two different mitochondria-targeted GQ binding compounds in primary fibroblasts from patients with m.10191T>C heteroplasmy. Treatment induced alternating mtDNA depletion and repopulation and was effective in shifting heteroplasmy towards the non-pathogenic allele. Similar treatment of pathogenic heteroplasmies that do not affect GQ formation did not induce heteroplasmy shift. Following treatment, heteroplasmic m.10191T>C cells had persistent improvements and heteroplasmy and a corresponding increase in maximal mitochondrial oxygen consumption. This study demonstrates the potential for using small-molecule GQ-binding agents to induce genetic and functional improvements in m.10191T>C heteroplasmy.
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Affiliation(s)
| | - Rathena Maheshan
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada
| | - Sheila R Costford
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada
| | - Azizia Wahedi
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada
| | - Marko Trajkovski
- National Institute of Chemistry, Slovenian NMR Center, Ljubljana, Slovenia
| | - Janez Plavec
- National Institute of Chemistry, Slovenian NMR Center, Ljubljana, Slovenia
| | - Liliya A Yatsunyk
- Department of Chemistry and Biochemistry, Swarthmore College, Swarthmore PA, USA
| | | | - Brett A Kaufman
- Center for Metabolism and Mitochondrial Medicine, Division of Cardiology, Vascular Medicine Institute, Department of Medicine, University of Pittsburgh Medical School, Pittsburgh, PA, USA
| | - Neal Sondheimer
- Institute of Medical Science.,Departments of Paediatrics and Molecular Genetics, The University of Toronto, Toronto, ON, Canada.,Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada
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11
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Khacho M, Harris R, Slack RS. Mitochondria as central regulators of neural stem cell fate and cognitive function. Nat Rev Neurosci 2019; 20:34-48. [PMID: 30464208 DOI: 10.1038/s41583-018-0091-3] [Citation(s) in RCA: 213] [Impact Index Per Article: 42.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Emerging evidence now indicates that mitochondria are central regulators of neural stem cell (NSC) fate decisions and are crucial for both neurodevelopment and adult neurogenesis, which in turn contribute to cognitive processes in the mature brain. Inherited mutations and accumulated damage to mitochondria over the course of ageing serve as key factors underlying cognitive defects in neurodevelopmental disorders and neurodegenerative diseases, respectively. In this Review, we explore the recent findings that implicate mitochondria as crucial regulators of NSC function and cognition. In this respect, mitochondria may serve as targets for stem-cell-based therapies and interventions for cognitive defects.
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Affiliation(s)
- Mireille Khacho
- Department of Biochemistry, Microbiology and Immunology, Ottawa Institute of Systems Biology (OISB), University of Ottawa, Ottawa, Ontario, Canada
| | - Richard Harris
- Department of Cellular and Molecular Medicine, University of Ottawa Brain and Mind Research Institute, Ottawa, Ontario, Canada
| | - Ruth S Slack
- Department of Cellular and Molecular Medicine, University of Ottawa Brain and Mind Research Institute, Ottawa, Ontario, Canada.
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12
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Whole-exome sequencing reveals a novel mutation of MT-ND5 gene in a mitochondrial cardiomyopathy pedigree: Patients who show biventricular hypertrophy, hyperlactacidemia, pulmonary hypertension, and decreased exercise tolerance. Anatol J Cardiol 2019; 21:18-24. [PMID: 30587702 PMCID: PMC6382902 DOI: 10.14744/anatoljcardiol.2018.53258] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Objective: The aim of the present study was to determine whether pathogenic mutations were present in families with mitochondrial cardiomyopathy that presented during adolescence. Methods: The proband was a 21-year-old man who presented clinically with palpitations, chest tightness, pulmonary hypertension, and limited exercise tolerance. Cardiac magnetic resonance imaging studies showed biventricular cardiac hypertrophy. We determine whether pathogenic mutations were present by whole-exome sequencing (WES) in families. Results: Screening of the family using tandem mass spectrometry showed elevated lactic acid levels, glutaric aciduria, a mildly increased glutarylcarnitine-to-octanoylcarnitine ratio, and normal blood α-glucosidase, which was consistent with a respiratory chain complex 1 metabolic disorder. We identified a novel mutation of MT-ND5, c.1315A>G (p.Thr439Ala). Skeletal muscle biopsy histology showed predominantly ragged red fibers and few ragged blue fibers, which was consistent with mitochondrial myopathy. Conclusion: In the present study, we identified a novel mutation of MT-ND5, c.1315A>G (p.Thr439Ala), in a family pedigree using WES.
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13
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Li TR, Wang Q, Liu MM, Lv RJ. A Chinese Family With Adult-Onset Leigh-Like Syndrome Caused by the Heteroplasmic m.10191T>C Mutation in the Mitochondrial MTND3 Gene. Front Neurol 2019; 10:347. [PMID: 31105631 PMCID: PMC6499163 DOI: 10.3389/fneur.2019.00347] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Accepted: 03/21/2019] [Indexed: 12/21/2022] Open
Abstract
Leigh syndrome (LS) is a mitochondrial disease of infancy and early childhood, that is rarely seen in adults. The high degree of genetic and clinical heterogeneity makes LS a very complex syndrome. The clinical manifestations include neurological symptoms and various non-neurological symptoms, with different mutations differing in presentations and therapies. The m.10191T>C mutation in the mitochondrial DNA gene encoding in the respiratory chain complex I (CI) subunit of MTND3 results in the substitution of a highly conserved amino acid (p.Ser45Pro) within the ND3 protein, leading to CI dysfunction and causing a broad clinical spectrum of disorders that includes LS. Patients with the m.10191T>C mutation are rare in general, even more so in adults. In the present study, we report a family of patients with very rare adult-onset Leigh-like syndrome with the m.10191T>C mutation. The 24-year-old proband presented with seizures 6 years ago and developed refractory status epilepticus on admission. She had acute encephalopathy accompanied by lactic acidosis, symmetrical putamen and scattered cortical lesions. The video electroencephalogram suggested focal-onset seizures. She harbored the heteroplasmic m.10191T>C mutation in her blood and fibroblasts. Her aunt was diagnosed with mitochondrial disease at the age of 42, and had the heteroplasmic m.10191T>C mutation in her fibroblasts. Her aunt's son (cousin) died of respiratory failure at the age of 8, and we suspected he was also a case of LS. Furthermore, we reviewed the previously reported patients with the m.10191T>C mutation and summarized their characteristics. Recognizing the characteristics of these patients will help us improve the clinical understanding of LS or Leigh-like syndrome.
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Affiliation(s)
- Tao-Ran Li
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, China National Clinical Research Center for Neurological Diseases, Beijing, China.,Department of Neurology, XuanWu Hospital of Capital Medical University, Beijing, China
| | - Qun Wang
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, China National Clinical Research Center for Neurological Diseases, Beijing, China
| | - Mao-Mao Liu
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, China National Clinical Research Center for Neurological Diseases, Beijing, China
| | - Rui-Juan Lv
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, China National Clinical Research Center for Neurological Diseases, Beijing, China
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14
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Yu XL, Yan CZ, Ji KQ, Lin PF, Xu XB, Dai TJ, Li W, Zhao YY. Clinical, Neuroimaging, and Pathological Analyses of 13 Chinese Leigh Syndrome Patients with Mitochondrial DNA Mutations. Chin Med J (Engl) 2019; 131:2705-2712. [PMID: 30425197 PMCID: PMC6247594 DOI: 10.4103/0366-6999.245265] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Background Leigh syndrome (LS) is a rare disease caused by mitochondrial defects and has high phenotypic and genotypic heterogeneity. We analyzed the clinical symptoms, neuroimaging, muscular histopathology, and genotypes of 13 Chinese LS patients with mitochondrial DNA (mtDNA) mutations. Methods Mutations in mtDNA were identified by targeted sequencing. The brain imaging features on magnetic resonance imaging (MRI) were analyzed. The levels of lactate in fasting blood and cerebrospinal fluid (CSF) were routinely tested. The levels of urinary organic acids, plasma amino acids, and acylcarnitines were examined with gas chromatography-mass spectrometry and tandem mass spectrometry. The histopathological traits of skeletal muscles were analyzed under microscope. Results Among 13 patients, mutations of MT-NDs (n = 8) and MT-ATP6 (n = 4) genes were most common. Strabismus (8/13), muscle weakness (8/13), and ataxia (5/13) were also common, especially for the patients with late-onset age after 2 years old. However, respiratory distress was common in patients with early-onset age before 2 years old. The most frequently affected brain area in these patients was the brain stem (12/13), particularly the dorsal part of midbrain, followed by basal ganglia (6/13), thalamus (6/13), cerebellum (5/13), and supratentorial white matter (2/13). Besides, the elevated lactate levels in CSF (6/6) were more common than those in serum (7/13). However, the analysis of abnormal plasma amino acid and urinary organic acid showed limited results (0/3 and 1/4, respectively). Muscular histopathology showed mitochondrial myopathy in the three late-onset patients but not in the early-onset ones. Conclusions Noninvasive genetic screening is recommended for mtDNA mutations in MT-NDs and MT-ATP6 genes in patients with ophthalmoplegia, muscle weakness, ataxia, and respiratory disorder. Furthermore, the lactate detection in CSF and the brain MRI scanning are suggested as the diagnosis methods for LS patients with mtDNA mutations.
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Affiliation(s)
- Xiao-Lin Yu
- Department of Geriatrics Medicine; Department of Neurology, Research Institute of Neuromuscular and Neurodegenerative Diseases; Key Laboratory of Cardiovascular Proteomics of Shandong Province, Qilu Hospital, Shandong University, Jinan, Shandong 250012, China
| | - Chuan-Zhu Yan
- Department of Neurology, Research Institute of Neuromuscular and Neurodegenerative Diseases, Qilu Hospital, Jinan, Shandong 250012; Mitochondrial Medicine Laboratory, Qilu Hospital (Qingdao), Shandong University, Qingdao, Shandong 266035; Brain Science Research Institute, Shandong University, Jinan, Shandong 250012, China
| | - Kun-Qian Ji
- Department of Neurology, Research Institute of Neuromuscular and Neurodegenerative Diseases, Qilu Hospital, Shandong University, Jinan, Shandong 250012, China
| | - Peng-Fei Lin
- Department of Neurology, Research Institute of Neuromuscular and Neurodegenerative Diseases, Qilu Hospital, Shandong University, Jinan, Shandong 250012, China
| | - Xue-Bi Xu
- Department of Neurology, Research Institute of Neuromuscular and Neurodegenerative Diseases, Qilu Hospital, Shandong University, Jinan, Shandong 250012, China
| | - Ting-Jun Dai
- Department of Neurology, Research Institute of Neuromuscular and Neurodegenerative Diseases, Qilu Hospital, Shandong University, Jinan, Shandong 250012, China
| | - Wei Li
- Department of Neurology, Research Institute of Neuromuscular and Neurodegenerative Diseases, Qilu Hospital, Shandong University, Jinan, Shandong 250012, China
| | - Yu-Ying Zhao
- Department of Neurology, Research Institute of Neuromuscular and Neurodegenerative Diseases, Qilu Hospital, Shandong University, Jinan, Shandong 250012, China
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15
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Pereira C, Souza CFD, Vedolin L, Vairo F, Lorea C, Sobreira C, Nogueira C, Vilarinho L. Leigh Syndrome Due to mtDNA Pathogenic Variants. JOURNAL OF INBORN ERRORS OF METABOLISM AND SCREENING 2019. [DOI: 10.1590/2326-4594-jiems-2018-0003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Affiliation(s)
| | | | | | | | - Cláudia Lorea
- Department of Clinical Genomics, USA; Universidade Federal de Pelotas, Brazil
| | | | - Célia Nogueira
- Instituto Nacional de Saúde Doutor Ricardo Jorge, Portugal
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16
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Cordeiro D, Bullivant G, Siriwardena K, Evans A, Kobayashi J, Cohn RD, Mercimek-Andrews S. Genetic landscape of pediatric movement disorders and management implications. NEUROLOGY-GENETICS 2018; 4:e265. [PMID: 30283815 PMCID: PMC6167181 DOI: 10.1212/nxg.0000000000000265] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/10/2018] [Accepted: 05/08/2018] [Indexed: 11/21/2022]
Abstract
Objective To identify underlying genetic causes in patients with pediatric movement disorders by genetic investigations. Methods All patients with a movement disorder seen in a single Pediatric Genetic Movement Disorder Clinic were included in this retrospective cohort study. We reviewed electronic patient charts for clinical, neuroimaging, biochemical, and molecular genetic features. DNA samples were used for targeted direct sequencing, targeted next-generation sequencing, or whole exome sequencing. Results There were 51 patients in the Pediatric Genetic Movement Disorder Clinic. Twenty-five patients had dystonia, 27 patients had ataxia, 7 patients had chorea-athetosis, 8 patients had tremor, and 7 patients had hyperkinetic movements. A genetic diagnosis was confirmed in 26 patients, including in 20 patients with ataxia and 6 patients with dystonia. Targeted next-generation sequencing panels confirmed a genetic diagnosis in 9 patients, and whole exome sequencing identified a genetic diagnosis in 14 patients. Conclusions We report a genetic diagnosis in 26 (51%) patients with pediatric movement disorders seen in a single Pediatric Genetic Movement Disorder Clinic. A genetic diagnosis provided either disease-specific treatment or effected management in 10 patients with a genetic diagnosis, highlighting the importance of early and specific diagnosis.
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Affiliation(s)
- Dawn Cordeiro
- Division of Clinical and Metabolic Genetics (D.C., G.B., R.D.C., S.M.-A.), Department of Pediatrics, Toronto, Ontario, Canada; Department of Medical Genetics (K.S.), University of Alberta, Edmonton, Canada; Department of Pediatrics (A.E., J.K., R.D.C., S.M.-A.), University of Toronto; the Emergency Medicine Division (A.E.), Department of Paediatrics, The Hospital for Sick Children; Division of Neurology (J.K.), Department of Paediatrics, The Hospital for Sick Children,; Genetics and Genome Biology Program (R.D.C., S.M.-A.), Research Institute, The Hospital for Sick Children; and Institute of Medical Sciences (S.M.-A.), University of Toronto, Toronto, Ontario, Canada
| | - Garrett Bullivant
- Division of Clinical and Metabolic Genetics (D.C., G.B., R.D.C., S.M.-A.), Department of Pediatrics, Toronto, Ontario, Canada; Department of Medical Genetics (K.S.), University of Alberta, Edmonton, Canada; Department of Pediatrics (A.E., J.K., R.D.C., S.M.-A.), University of Toronto; the Emergency Medicine Division (A.E.), Department of Paediatrics, The Hospital for Sick Children; Division of Neurology (J.K.), Department of Paediatrics, The Hospital for Sick Children,; Genetics and Genome Biology Program (R.D.C., S.M.-A.), Research Institute, The Hospital for Sick Children; and Institute of Medical Sciences (S.M.-A.), University of Toronto, Toronto, Ontario, Canada
| | - Komudi Siriwardena
- Division of Clinical and Metabolic Genetics (D.C., G.B., R.D.C., S.M.-A.), Department of Pediatrics, Toronto, Ontario, Canada; Department of Medical Genetics (K.S.), University of Alberta, Edmonton, Canada; Department of Pediatrics (A.E., J.K., R.D.C., S.M.-A.), University of Toronto; the Emergency Medicine Division (A.E.), Department of Paediatrics, The Hospital for Sick Children; Division of Neurology (J.K.), Department of Paediatrics, The Hospital for Sick Children,; Genetics and Genome Biology Program (R.D.C., S.M.-A.), Research Institute, The Hospital for Sick Children; and Institute of Medical Sciences (S.M.-A.), University of Toronto, Toronto, Ontario, Canada
| | - Andrea Evans
- Division of Clinical and Metabolic Genetics (D.C., G.B., R.D.C., S.M.-A.), Department of Pediatrics, Toronto, Ontario, Canada; Department of Medical Genetics (K.S.), University of Alberta, Edmonton, Canada; Department of Pediatrics (A.E., J.K., R.D.C., S.M.-A.), University of Toronto; the Emergency Medicine Division (A.E.), Department of Paediatrics, The Hospital for Sick Children; Division of Neurology (J.K.), Department of Paediatrics, The Hospital for Sick Children,; Genetics and Genome Biology Program (R.D.C., S.M.-A.), Research Institute, The Hospital for Sick Children; and Institute of Medical Sciences (S.M.-A.), University of Toronto, Toronto, Ontario, Canada
| | - Jeff Kobayashi
- Division of Clinical and Metabolic Genetics (D.C., G.B., R.D.C., S.M.-A.), Department of Pediatrics, Toronto, Ontario, Canada; Department of Medical Genetics (K.S.), University of Alberta, Edmonton, Canada; Department of Pediatrics (A.E., J.K., R.D.C., S.M.-A.), University of Toronto; the Emergency Medicine Division (A.E.), Department of Paediatrics, The Hospital for Sick Children; Division of Neurology (J.K.), Department of Paediatrics, The Hospital for Sick Children,; Genetics and Genome Biology Program (R.D.C., S.M.-A.), Research Institute, The Hospital for Sick Children; and Institute of Medical Sciences (S.M.-A.), University of Toronto, Toronto, Ontario, Canada
| | - Ronald D Cohn
- Division of Clinical and Metabolic Genetics (D.C., G.B., R.D.C., S.M.-A.), Department of Pediatrics, Toronto, Ontario, Canada; Department of Medical Genetics (K.S.), University of Alberta, Edmonton, Canada; Department of Pediatrics (A.E., J.K., R.D.C., S.M.-A.), University of Toronto; the Emergency Medicine Division (A.E.), Department of Paediatrics, The Hospital for Sick Children; Division of Neurology (J.K.), Department of Paediatrics, The Hospital for Sick Children,; Genetics and Genome Biology Program (R.D.C., S.M.-A.), Research Institute, The Hospital for Sick Children; and Institute of Medical Sciences (S.M.-A.), University of Toronto, Toronto, Ontario, Canada
| | - Saadet Mercimek-Andrews
- Division of Clinical and Metabolic Genetics (D.C., G.B., R.D.C., S.M.-A.), Department of Pediatrics, Toronto, Ontario, Canada; Department of Medical Genetics (K.S.), University of Alberta, Edmonton, Canada; Department of Pediatrics (A.E., J.K., R.D.C., S.M.-A.), University of Toronto; the Emergency Medicine Division (A.E.), Department of Paediatrics, The Hospital for Sick Children; Division of Neurology (J.K.), Department of Paediatrics, The Hospital for Sick Children,; Genetics and Genome Biology Program (R.D.C., S.M.-A.), Research Institute, The Hospital for Sick Children; and Institute of Medical Sciences (S.M.-A.), University of Toronto, Toronto, Ontario, Canada
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Abstract
BACKGROUND Given the etiologic heterogeneity of disease classification using clinical phenomenology, we employed contemporary criteria to classify variants associated with myoclonic epilepsy with ragged-red fibers (MERRF) syndrome and to assess the strength of evidence of gene-disease associations. Standardized approaches are used to clarify the definition of MERRF, which is essential for patient diagnosis, patient classification, and clinical trial design. METHODS Systematic literature and database search with application of standardized assessment of gene-disease relationships using modified Smith criteria and of variants reported to be associated with MERRF using modified Yarham criteria. RESULTS Review of available evidence supports a gene-disease association for two MT-tRNAs and for POLG. Using modified Smith criteria, definitive evidence of a MERRF gene-disease association is identified for MT-TK. Strong gene-disease evidence is present for MT-TL1 and POLG. Functional assays that directly associate variants with oxidative phosphorylation impairment were critical to mtDNA variant classification. In silico analysis was of limited utility to the assessment of individual MT-tRNA variants. With the use of contemporary classification criteria, several mtDNA variants previously reported as pathogenic or possibly pathogenic are reclassified as neutral variants. CONCLUSIONS MERRF is primarily an MT-TK disease, with pathogenic variants in this gene accounting for ~90% of MERRF patients. Although MERRF is phenotypically and genotypically heterogeneous, myoclonic epilepsy is the clinical feature that distinguishes MERRF from other categories of mitochondrial disorders. Given its low frequency in mitochondrial disorders, myoclonic epilepsy is not explained simply by an impairment of cellular energetics. Although MERRF phenocopies can occur in other genes, additional data are needed to establish a MERRF disease-gene association. This approach to MERRF emphasizes standardized classification rather than clinical phenomenology, thus improving patient diagnosis and clinical trial design.
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18
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Nissanka N, Moraes CT. Mitochondrial DNA damage and reactive oxygen species in neurodegenerative disease. FEBS Lett 2018; 592:728-742. [PMID: 29281123 DOI: 10.1002/1873-3468.12956] [Citation(s) in RCA: 252] [Impact Index Per Article: 42.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2017] [Revised: 12/06/2017] [Accepted: 12/19/2017] [Indexed: 12/12/2022]
Abstract
Mitochondria are essential organelles within the cell where most ATP is produced through oxidative phosphorylation (OXPHOS). A subset of the genes needed for this process are encoded by the mitochondrial DNA (mtDNA). One consequence of OXPHOS is the production of mitochondrial reactive oxygen species (ROS), whose role in mediating cellular damage, particularly in damaging mtDNA during ageing, has been controversial. There are subsets of neurons that appear to be more sensitive to ROS-induced damage, and mitochondrial dysfunction has been associated with several neurodegenerative disorders. In this review, we will discuss the current knowledge in the field of mtDNA and neurodegeneration, the debate about ROS as a pathological or beneficial contributor to neuronal function, bona fide mtDNA diseases, and insights from mouse models of mtDNA defects affecting the central nervous system.
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Affiliation(s)
- Nadee Nissanka
- Neuroscience Graduate Program, University of Miami Miller School of Medicine, FL, USA
| | - Carlos T Moraes
- Neuroscience Graduate Program, University of Miami Miller School of Medicine, FL, USA.,Department of Neurology, University of Miami Miller School of Medicine, FL, USA
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19
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Mezuki S, Fukuda K, Matsushita T, Fukushima Y, Matsuo R, Goto YI, Yasukawa T, Uchiumi T, Kang D, Kitazono T, Ago T. Isolated and repeated stroke-like episodes in a middle-aged man with a mitochondrial ND3 T10158C mutation: a case report. BMC Neurol 2017; 17:217. [PMID: 29237403 PMCID: PMC5729248 DOI: 10.1186/s12883-017-1001-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 12/05/2017] [Indexed: 12/31/2022] Open
Abstract
Background Mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS) syndrome, is the most common phenotype of mitochondrial disease. It often develops in childhood or adolescence, usually before the age of 40, in a maternally-inherited manner. Mutations in mitochondrial DNA (mtDNA) are frequently responsible for MELAS. Case presentation A 55-year-old man, who had no family or past history of mitochondrial disorders, suddenly developed bilateral visual field constriction and repeated stroke-like episodes. He ultimately presented with cortical blindness, recurrent epilepsy and severe cognitive impairment approximately 6 months after the first episode. Genetic analysis of biopsied biceps brachii muscle, but not of peripheral white blood cells, revealed a T10158C mutation in the mtDNA-encoded gene of NADH dehydrogenase subunit 3 (ND3), which has previously been thought to be associated with severe or fatal mitochondrial disorders that develop during the neonatal period or in infancy. Conclusion A T10158C mutation in the ND3 gene can cause atypical adult-onset stroke-like episodes in a sporadic manner.
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Affiliation(s)
- Satomi Mezuki
- Stroke Center, St. Mary's Hospital, 422 Tsubukuhonmachi, Kurume, 830-8543, Japan. .,Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.
| | - Kenji Fukuda
- Stroke Center, St. Mary's Hospital, 422 Tsubukuhonmachi, Kurume, 830-8543, Japan
| | - Tomonaga Matsushita
- Stroke Center, St. Mary's Hospital, 422 Tsubukuhonmachi, Kurume, 830-8543, Japan
| | - Yoshihisa Fukushima
- Stroke Center, St. Mary's Hospital, 422 Tsubukuhonmachi, Kurume, 830-8543, Japan
| | - Ryu Matsuo
- Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Yu-Ichi Goto
- Department of Mental Retardation and Birth Defect Research, National Institute of Neuroscience, NCNP, 4-1-1 Ogawa-Higashi, Kodaira, Tokyo, 187-8551, Japan
| | - Takehiro Yasukawa
- Department of Pathological Sciences, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Takeshi Uchiumi
- Department of Pathological Sciences, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Dongchon Kang
- Department of Pathological Sciences, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Takanari Kitazono
- Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Tetsuro Ago
- Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.
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20
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Tavares WC, Seuánez HN. Disease-associated mitochondrial mutations and the evolution of primate mitogenomes. PLoS One 2017; 12:e0177403. [PMID: 28510580 PMCID: PMC5433710 DOI: 10.1371/journal.pone.0177403] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 04/26/2017] [Indexed: 01/09/2023] Open
Abstract
Several human diseases have been associated with mutations in mitochondrial genes comprising a set of confirmed and reported mutations according to the MITOMAP database. An analysis of complete mitogenomes across 139 primate species showed that most confirmed disease-associated mutations occurred in aligned codon positions and gene regions under strong purifying selection resulting in a strong evolutionary conservation. Only two confirmed variants (7.1%), coding for the same amino acids accounting for severe human diseases, were identified without apparent pathogenicity in non-human primates, like the closely related Bornean orangutan. Conversely, reported disease-associated mutations were not especially concentrated in conserved codon positions, and a large fraction of them occurred in highly variable ones. Additionally, 88 (45.8%) of reported mutations showed similar variants in several non-human primates and some of them have been present in extinct species of the genus Homo. Considering that recurrent mutations leading to persistent variants throughout the evolutionary diversification of primates are less likely to be severely damaging to fitness, we suggest that these 88 mutations are less likely to be pathogenic. Conversely, 69 (35.9%) of reported disease-associated mutations occurred in extremely conserved aligned codon positions which makes them more likely to damage the primate mitochondrial physiology.
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Affiliation(s)
- William Corrêa Tavares
- Programa de Genética, Instituto Nacional de Câncer, Rio de Janeiro, Rio de Janeiro, Brazil
- Departamento de Genética, Instituto de Biologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
- Departamento de Zoologia, Instituto de Biologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Héctor N. Seuánez
- Programa de Genética, Instituto Nacional de Câncer, Rio de Janeiro, Rio de Janeiro, Brazil
- Departamento de Genética, Instituto de Biologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
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21
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Krysko KM, Sundaram ANE. Recurrent Alternate-Sided Homonymous Hemianopia Due to Mitochondrial Encephalomyopathy with Lactic Acidosis and Stroke-Like Episodes (MELAS): A Case Report. Neuroophthalmology 2017; 41:30-34. [PMID: 28228835 DOI: 10.1080/01658107.2016.1224256] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 08/09/2016] [Accepted: 08/10/2016] [Indexed: 10/21/2022] Open
Abstract
Mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS) can rarely cause alternate-sided homonymous hemianopia due to stroke-like episodes involving the occipital lobes, as reported in three previously published cases. The authors report an interesting case of a 16-year-old presenting with myoclonic epilepsy due to MELAS with the rare ND3 mitochondrial mutation T10191C, with recurrent alternate-sided homonymous hemianopia. Visual field and corresponding magnetic resonance imaging (MRI) findings are presented. To the authors' knowledge, this is the first report of recurrent alternate-sided homonymous hemianopia in MELAS with documented visual field and MRI findings with resolution between each episode.
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Affiliation(s)
- Kristen M Krysko
- Division of Neurology, University of Toronto , Toronto, Ontario, Canada
| | - Arun N E Sundaram
- Division of Neurology, University of Toronto, Toronto, Ontario, Canada; Department of Ophthalmology and Visual Sciences, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada
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22
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Mukai M, Nagata E, Mizuma A, Yamano M, Sugaya K, Nishino I, Goto YI, Takizawa S. Adult-onset Mitochondrial Myopathy, Encephalopathy, Lactic Acidosis, and Stroke (MELAS)-like Encephalopathy Diagnosed Based on the Complete Sequencing of Mitochondrial DNA Extracted from Biopsied Muscle without any Myopathic Changes. Intern Med 2017; 56:95-99. [PMID: 28050007 PMCID: PMC5313432 DOI: 10.2169/internalmedicine.56.7301] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The clinical features of mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) are not uniform. We herein report a male patient with unusual MELAS-like encephalopathy who had been experiencing isolated recurrent stroke-like episodes since he was 33 years old without any particular family history. Despite an extensive investigation, he had no other signs suggestive of MELAS. Although the muscle pathology showed a normal appearance, a mitochondrial genome sequence analysis of the biopsied muscle revealed a heteroplasmic m.10158T>C mutation in the mitochondrial complex I subunit gene, MT-ND3. To prevented further deterioration of the higher brain function, the early diagnosis and treatment of mitochondrial stroke-like episodes is important.
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Affiliation(s)
- Masako Mukai
- Department of Neurology, Tokai University School of Medicine, Japan
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23
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Mitochondrial Encephalopathy and Optic Neuropathy Due to m.10158 MT-ND3 Complex I Mutation Presenting in an Adult Patient. Neurologist 2016; 21:61-5. [DOI: 10.1097/nrl.0000000000000084] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Levy RJ, Ríos PG, Akman HO, Sciacco M, De Vivo DC, DiMauro S. Long survival in patients with leigh syndrome and the m.10191T>C mutation in MT-ND3 : a case report and review of the literature. J Child Neurol 2014; 29:NP105-10. [PMID: 24284231 PMCID: PMC4035473 DOI: 10.1177/0883073813506783] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We report an unusual case of Leigh syndrome due to the m.10191T>C mutation in the complex I gene MT-ND3. This mutation has been associated with a spectrum of clinical phenotypes ranging from infant lethality to adult onset. Despite infantile onset and severe symptoms, our patient has survived to early adulthood because of a strict dietary regimen and parental care. This patient is an extreme example of the frequently prolonged course of Leigh syndrome due to this particular mutation.
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Affiliation(s)
- Rebecca J. Levy
- Department of Neurology, Columbia University Medical Center, New York, NY, USA
| | | | - Hasan O. Akman
- Department of Neurology, Columbia University Medical Center, New York, NY, USA
| | - Monica Sciacco
- Neuromuscular Unit, IRCCS Foundation Ca’ Granda Ospedale Maggiore Policlinico, Dino Ferrari Centre, University of Milan, 20122 Milan, Italy
| | - Darryl C. De Vivo
- Department of Neurology, Columbia University Medical Center, New York, NY, USA
| | - Salvatore DiMauro
- Department of Neurology, Columbia University Medical Center, New York, NY, USA
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25
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Leng Y, Liu Y, Fang X, Li Y, Yu L, Yuan Y, Wang Z. The mitochondrial DNA 10197 G > A mutation causes MELAS/Leigh overlap syndrome presenting with acute auditory agnosia. ACTA ACUST UNITED AC 2014; 26:208-12. [PMID: 24708134 DOI: 10.3109/19401736.2014.905860] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes/Leigh (MELAS/LS) overlap syndrome is a mitochondrial disorder subtype with clinical and magnetic resonance imaging (MRI) features that are characteristic of both MELAS and Leigh syndrome (LS). Here, we report an MELAS/LS case presenting with cortical deafness and seizures. Cranial MRI revealed multiple lesions involving bilateral temporal lobes, the basal ganglia and the brainstem, which conformed to neuroimaging features of both MELAS and LS. Whole mitochondrial DNA (mtDNA) sequencing and PCR-RFLP revealed a de novo heteroplasmic m.10197 G > A mutation in the NADH dehydrogenase subunit 3 gene (ND3), which was predicted to cause an alanine to threonine substitution at amino acid 47. Although the mtDNA m.10197 G > A mutation has been reported in association with LS, Leber hereditary optic neuropathy and dystonia, it has never been linked with MELAS/LS overlap syndrome. Our patient therefore expands the phenotypic spectrum of the mtDNA m.10197 G > A mutation.
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Affiliation(s)
- Yinglin Leng
- Department of Neurology, Peking University First Hospital , Beijing , China
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26
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Finsterer J, Zarrouk Mahjoub S. Mitochondrial epilepsy in pediatric and adult patients. Acta Neurol Scand 2013; 128:141-52. [PMID: 23480231 DOI: 10.1111/ane.12122] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/11/2013] [Indexed: 01/04/2023]
Abstract
Few data are available about the difference between epilepsy in pediatric mitochondrial disorders (MIDs) and adult MIDs. This review focuses on the differences between pediatric and adult mitochondrial epilepsy with regard to seizure type, seizure frequency, and underlying MID. A literature search via Pubmed using the keywords 'mitochondrial', 'epilepsy', 'seizures', 'adult', 'pediatric', and all MID acronyms, was carried out. Frequency of mitochondrial epilepsy strongly depends on the type of MID included and is higher in pediatric compared to adult patients. In pediatric patients, mitochondrial epilepsy is more frequent due to mutations in nDNA-located than mtDNA-located genes and vice versa in adults. In pediatric patients, mitochondrial epilepsy is associated with a syndromic phenotype in half of the patients and in adults more frequently with a non-syndromic phenotype. In pediatric patients, focal seizures are more frequent than generalized seizures and vice versa in adults. Electro-clinical syndromes are more frequent in pediatric MIDs compared to adult MIDs. Differences between pediatric and adult mitochondrial epilepsy concern the onset of epilepsy, frequency of epilepsy, seizure type, type of electro-clinical syndrome, frequency of syndromic versus non-syndromic MIDs, and the outcome. To optimize management of mitochondrial epilepsy, it is essential to differentiate between early and late-onset forms.
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Affiliation(s)
| | - S. Zarrouk Mahjoub
- Laboratory of Biochemistry; UR ‘Human Nutrition and Metabolic Disorders’ Faculty of Medicine Monastir; Tunisia
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27
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Tang S, Wang J, Zhang VW, Li FY, Landsverk M, Cui H, Truong CK, Wang G, Chen LC, Graham B, Scaglia F, Schmitt ES, Craigen WJ, Wong LJC. Transition to next generation analysis of the whole mitochondrial genome: a summary of molecular defects. Hum Mutat 2013; 34:882-93. [PMID: 23463613 DOI: 10.1002/humu.22307] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Accepted: 02/15/2013] [Indexed: 01/06/2023]
Abstract
The diagnosis of mitochondrial disorders is challenging because of the clinical variability and genetic heterogeneity. Conventional analysis of the mitochondrial genome often starts with a screening panel for common mitochondrial DNA (mtDNA) point mutations and large deletions (mtScreen). If negative, it has been traditionally followed by Sanger sequencing of the entire mitochondrial genome (mtWGS). The recently developed "Next-Generation Sequencing" (NGS) technology offers a robust high-throughput platform for comprehensive mtDNA analysis. Here, we summarize the results of the past 6 years of clinical practice using the mtScreen and mtWGS tests on 9,261 and 2,851 unrelated patients, respectively. A total of 344 patients (3.7%) had mutations identified by mtScreen and 99 (3.5%) had mtDNA mutations identified by mtWGS. The combinatorial analyses of mtDNA and POLG revealed a diagnostic yield of 6.7% in patients with suspected mitochondrial disorders but no recognizable syndromes. From the initial mtWGS-NGS cohort of 391 patients, 21 mutation-positive cases (5.4%) have been identified. The mtWGS-NGS provides a one-step approach to detect common and uncommon point mutations, as well as deletions. Additionally, NGS provides accurate, sensitive heteroplasmy measurement, and the ability to map deletion breakpoints. A new era of more efficient molecular diagnosis of mtDNA mutations has arrived.
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Affiliation(s)
- Sha Tang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
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28
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Shanske S, Naini A, Chmait RH, Akman HO, Mansukhani M, Lu J, Hirano M, DiMauro S. Mutation in an mtDNA protein-coding gene: prenatal diagnosis aided by fetal muscle biopsy. J Child Neurol 2013; 28:264-8. [PMID: 22532554 PMCID: PMC3959766 DOI: 10.1177/0883073812441067] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Prenatal diagnosis of disorders due to mitochondrial DNA (mtDNA) tRNA gene mutations is problematic. Experience in families harboring the protein-coding ATPase 6 m.8993T>G mutation suggests that the mutant load is homogeneous in different tissues, thus allowing prenatal diagnosis. We have encountered a novel protein-coding gene mutation, m.10198C>T in MT-ND3. A baby girl homoplasmic for this mutation died at 3 months after severe psychomotor regression and respiratory arrest. The mother had no detectable mutation in accessible tissues. The product of a second pregnancy showed only wild-type mt genomes in amniocytes, chorionic villi, and biopsied fetal muscle. This second girl is now 18 months old and healthy. Our observations support the concept that the pathogenic mutation in this patient appeared de novo and that fetal muscle biopsy is a useful aide in prenatal diagnosis.
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Affiliation(s)
- Sara Shanske
- Department of Neurology, Columbia University Medical Center, New York, NY, USA
| | - Ali Naini
- Department of Neurology, Columbia University Medical Center, New York, NY, USA,Department of Pathology and Cell Biology, Columbia University Medical Center, New York, NY, USA
| | - Ramen H. Chmait
- Department of Obstetrics, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Hasan O. Akman
- Department of Neurology, Columbia University Medical Center, New York, NY, USA
| | - Mahesh Mansukhani
- Department of Pathology and Cell Biology, Columbia University Medical Center, New York, NY, USA
| | - Jiesheng Lu
- Department of Neurology, Columbia University Medical Center, New York, NY, USA
| | - Michio Hirano
- Department of Neurology, Columbia University Medical Center, New York, NY, USA
| | - Salvatore DiMauro
- Department of Neurology, Columbia University Medical Center, New York, NY, USA
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29
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Iommarini L, Calvaruso MA, Kurelac I, Gasparre G, Porcelli AM. Complex I impairment in mitochondrial diseases and cancer: Parallel roads leading to different outcomes. Int J Biochem Cell Biol 2013; 45:47-63. [DOI: 10.1016/j.biocel.2012.05.016] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Revised: 05/03/2012] [Accepted: 05/24/2012] [Indexed: 02/06/2023]
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30
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Hoefs SJ, Rodenburg RJ, Smeitink JA, van den Heuvel LP. Molecular base of biochemical complex I deficiency. Mitochondrion 2012; 12:520-32. [DOI: 10.1016/j.mito.2012.07.106] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2011] [Revised: 07/06/2012] [Accepted: 07/10/2012] [Indexed: 12/21/2022]
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31
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Abstract
Among the various central nervous system (CNS) manifestations of mitochondrial disorders (MIDs), cognitive impairment is increasingly recognized and diagnosed (mitochondrial cognitive dysfunction). Aim of the review was to summarize recent findings concerning the aetiology, pathogenesis, diagnosis and treatment of cognitive decline in MIDs. Among syndromic MIDs due to mitochondrial DNA (mtDNA) mutations, cognitive impairment occurs in patients with mitochondrial encephalopathy, lactic acidosis and stroke-like episodes syndrome, myoclonus epilepsy with ragged-red fibres syndrome, mitochondrial chronic progressive external ophthalmoplegia, Kearns-Sayre syndrome, neuropathy, ataxia and retinitis pigmentosa syndrome and maternally inherited diabetes and deafness. Among syndromic MIDs due to nuclear DNA (nDNA) mutations, cognitive decline has been reported in myo-neuro-gastro-intestinal encephalopathy, mitochondrial recessive ataxia syndrome, spinocerebellar ataxia with encephalopathy, Mohr-Tranebjaerg syndrome, leuko-encephalopathy; brain and spinal cord involvement and lactic acidosis, CMT2, Wolfram syndrome, Wolf-Hirschhorn syndrome and Leigh syndrome. In addition to syndromic MIDs, a large number of non-syndromic MIDs due to mtDNA as well as nDNA mutations have been reported, which present with cognitive impairment as the sole or one among several other CNS manifestations of a MID. Delineation of mitochondrial cognitive impairment from other types of cognitive impairment is essential to guide the optimal management of these patients. Treatment of mitochondrial cognitive impairment is largely limited to symptomatic and supportive measures. Cognitive impairment may be a CNS manifestation of syndromic as well as non-syndromic MIDs. Correct diagnosis of mitochondrial cognitive impairment is a prerequisite for the optimal management of these patients.
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Affiliation(s)
- J. Finsterer
- Danube University Krems; Krems and Krankenanstalt Rudolfstiftung; Vienna; Austria
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32
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Nesbitt V, Morrison PJ, Crushell E, Donnelly DE, Alston CL, He L, McFarland R, Taylor RW. The clinical spectrum of the m.10191T>C mutation in complex I-deficient Leigh syndrome. Dev Med Child Neurol 2012; 54:500-6. [PMID: 22364517 DOI: 10.1111/j.1469-8749.2012.04224.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Mitochondrial respiratory chain diseases represent one of the most common inherited neurometabolic disorders of childhood, affecting a minimum of 1 in 7500 live births. The marked clinical, biochemical, and genetic heterogeneity means that accurate genetic counselling relies heavily upon the identification of the underlying causative mutation in the individual and determination of carrier status in the parents. Isolated complex I deficiency is the most common respiratory chain defect observed in children, resulting in organ-specific or multisystem disease, but most often presenting as Leigh syndrome, for which mitochondrial DNA mutations are important causes. Several recurrent, pathogenic point mutations in the MTND3 gene - including m.10191T>C (p.Ser45Pro) - have been previously identified. In this short clinical review we evaluate the case reports of the m.10191T>C mutation causing complex I-deficient Leigh syndrome described in the literature, in addition to two new ones diagnosed in our laboratory. Both of these appear to have arisen de novo without transmission of the mutation from mother to offspring, illustrating the importance not only of fully characterizing the mitochondrial genome as part of the investigation of children with complex I-deficient Leigh syndrome but also of assessing maternal samples to provide crucial genetic advice for families.
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Affiliation(s)
- Victoria Nesbitt
- Mitochondrial Research Group, Institute for Ageing and Health, Newcastle University, Newcastle Upon Tyne, UK
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33
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Mutations in mitochondrially encoded complex I enzyme as the second common cause in a cohort of Chinese patients with mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes. J Hum Genet 2011; 56:759-64. [DOI: 10.1038/jhg.2011.96] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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34
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Leshinsky-Silver E, Shuvalov R, Inbar S, Cohen S, Lev D, Lerman-Sagie T. Juvenile Leigh syndrome, optic atrophy, ataxia, dystonia, and epilepsy due to T14487C mutation in the mtDNA-ND6 gene: a mitochondrial syndrome presenting from birth to adolescence. J Child Neurol 2011; 26:476-81. [PMID: 21196529 DOI: 10.1177/0883073810384615] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
An increasing number of reports describe mutations in mitochondrial DNA coding regions, especially in mitochondrial DNA- encoded nicotinamide adenine dinucleotide dehydrogenase subunit genes of the respiratory chain complex I, as causing early-onset Leigh syndrome. The authors report the molecular findings in a 24-year-old patient with juvenile-onset Leigh syndrome presenting with optic atrophy, ataxia dystonia, and epilepsy. A brain magnetic resonance imaging revealed bilateral basal ganglia and thalamic hypointensities, and a magnetic resonance spectroscopy revealed an increased lactate peak. The authors identified a T14487C change causing M63V substitution in the mitochondrial ND6 gene. The mutation was heteroplasmic in muscle and blood samples, with different mutation loads, and was absent in the patient's mother's urine and blood samples. They suggest that the T14487C mtDNA mutation should be analyzed in Leigh syndrome, presenting with optic atrophy, ataxia, dystonia, and epilepsy, regardless of age.
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35
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Zsurka G, Kunz WS. Mitochondrial dysfunction in neurological disorders with epileptic phenotypes. J Bioenerg Biomembr 2010; 42:443-8. [DOI: 10.1007/s10863-010-9314-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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36
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Gerards M, van den Bosch BJC, Danhauser K, Serre V, van Weeghel M, Wanders RJA, Nicolaes GAF, Sluiter W, Schoonderwoerd K, Scholte HR, Prokisch H, Rötig A, de Coo IFM, Smeets HJM. Riboflavin-responsive oxidative phosphorylation complex I deficiency caused by defective ACAD9: new function for an old gene. Brain 2010; 134:210-9. [DOI: 10.1093/brain/awq273] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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37
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Choi BO, Hwang JH, Cho EM, Jeong EH, Hyun YS, Jeon HJ, Seong KM, Cho NS, Chung KW. Mutational analysis of whole mitochondrial DNA in patients with MELAS and MERRF diseases. Exp Mol Med 2010; 42:446-55. [PMID: 20440095 DOI: 10.3858/emm.2010.42.6.046] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Mitochondrial diseases are clinically and genetically heterogeneous disorders, which make the exact diagnosis and classification difficult. The purpose of this study was to identify pathogenic mtDNA mutations in 61 Korean unrelated families (or isolated patients) with MELAS or MERRF. In particular, the mtDNA sequences were completely determined for 49 patients. From the mutational analysis of mtDNA obtained from blood, 5 confirmed pathogenic mutations were identified in 17 families, and 4 unreported pathogenically suspected mutations were identified in 4 families. The m.3243A>G in the tRNA(Leu(UUR))was predominantly observed in 10 MELAS families, and followed by m.8344A>G in the tRNA(Lys) of 4 MERRF families. Most pathogenic mutations showed heteroplasmy, and the rates were considerably different within the familial members. Patients with a higher rate of mutations showed a tendency of having more severe clinical phenotypes, but not in all cases. This study will be helpful for the molecular diagnosis of mitochondrial diseases, as well as establishment of mtDNA database in Koreans.
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Affiliation(s)
- Byung-Ok Choi
- Department of Neurology, Ewha Womans University, School of Medicine, Ewha Medical Research Institute, Seoul, Korea
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38
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Leshinsky-Silver E, Lev D, Malinger G, Shapira D, Cohen S, Lerman-Sagie T, Saada A. Leigh disease presenting in utero due to a novel missense mutation in the mitochondrial DNA-ND3. Mol Genet Metab 2010; 100:65-70. [PMID: 20202874 DOI: 10.1016/j.ymgme.2010.02.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2010] [Revised: 02/03/2010] [Accepted: 02/03/2010] [Indexed: 11/25/2022]
Abstract
Leigh syndrome can be caused by defects in both nuclear and mitochondrial genes involved in energy metabolism. Recently, an increasing number of mutations in mitochondrial DNA encoding regions, especially in NADH dehydrogenase (respiratory chain complex I) subunits, have been reported as causative of early onset Leigh syndrome. We describe a patient whose fetal brain ultrasound demonstrated periventricular pseudocyst suggestive of a possible mitochondrial disorder who presented postnatally with Leigh syndrome. A muscle biopsy demonstrated a partial decrease in complex I and pyruvate dehydrogenase (PDH-E1 alpha) activity. Sequencing of the PDH-E1 alpha gene did not reveal any mutation. Sequencing of the mtDNA revealed a novel heteroplasmic G10254A (D66N) mutation in the ND3 gene. This change results in a substitution of aspartic acid to asparagine in a highly conserved domain of the ND3 subunit. The mutation could not be detected in the mother's blood or urine sediment. Blue native gel electrophoresis of muscle mitochondria revealed a normal size, albeit a decreased level of complex I. The G10254A substitution in the mtDNA-ND3 gene is another cause of maternally inherited Leigh syndrome. This case demonstrates that periventricular pseudocysts may be the initial in utero presentation in patients with mitochondrial disorders. We emphasize the importance of screening the mtDNA in pediatric patients as the first step in molecular diagnosis of Leigh syndrome.
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39
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Bhardwaj A, Mukerji M, Sharma S, Paul J, Gokhale CS, Srivastava AK, Tiwari S. MtSNPscore: a combined evidence approach for assessing cumulative impact of mitochondrial variations in disease. BMC Bioinformatics 2009; 10 Suppl 8:S7. [PMID: 19758471 PMCID: PMC2745589 DOI: 10.1186/1471-2105-10-s8-s7] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Human mitochondrial DNA (mtDNA) variations have been implicated in a broad spectrum of diseases. With over 3000 mtDNA variations reported across databases, establishing pathogenicity of variations in mtDNA is a major challenge. We have designed and developed a comprehensive weighted scoring system (MtSNPscore) for identification of mtDNA variations that can impact pathogenicity and would likely be associated with disease. The criteria for pathogenicity include information available in the literature, predictions made by various in silico tools and frequency of variation in normal and patient datasets. The scoring scheme also assigns scores to patients and normal individuals to estimate the cumulative impact of variations. The method has been implemented in an automated pipeline and has been tested on Indian ataxia dataset (92 individuals), sequenced in this study, and other publicly available mtSNP dataset comprising of 576 mitochondrial genomes of Japanese individuals from six different groups, namely, patients with Parkinson's disease, patients with Alzheimer's disease, young obese males, young non-obese males, and type-2 diabetes patients with or without severe vascular involvement. MtSNPscore, for analysis can extract information from variation data or from mitochondrial DNA sequences. It has a web-interface http://bioinformatics.ccmb.res.in/cgi-bin/snpscore/Mtsnpscore.pl that provides flexibility to update/modify the parameters for estimating pathogenicity. RESULTS Analysis of ataxia and mtSNP data suggests that rare variants comprise the largest part of disease associated variations. MtSNPscore predicted possible role of eight and 79 novel variations in ataxia and mtSNP datasets, respectively, in disease etiology. Analysis of cumulative scores of patient and normal data resulted in Matthews Correlation Coefficient (MCC) of ~0.5 and accuracy of ~0.7 suggesting that the method may also predict involvement of mtDNA variation in diseases. CONCLUSION We have developed a novel and comprehensive method for evaluation of mitochondrial variation and their involvement in disease. Our method has the most comprehensive set of parameters to assess mtDNA variations and overcomes the undesired bias generated as a result of better-studied diseases and genes. These variations can be prioritized for functional assays to confirm their pathogenic status.
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Affiliation(s)
- Anshu Bhardwaj
- Institute of Genomics and Integrative Biology, CSIR, Delhi, India.
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40
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Rolandic mitochondrial encephalomyelopathy and MT-ND3 mutations. Pediatr Neurol 2009; 41:27-33. [PMID: 19520270 DOI: 10.1016/j.pediatrneurol.2009.02.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2008] [Revised: 02/09/2009] [Accepted: 02/16/2009] [Indexed: 11/22/2022]
Abstract
Mitochondrial encephalopathies may be caused by mutations in the respiratory chain complex I subunit genes. Described here are the cases of two pediatric patients who presented with MELAS-like calcarine lesions in addition to novel, bilateral rolandic lesions and epilepsia partialis continua, secondary to MT-ND3 mutations. Data were collected included neurologic symptoms, serial brain imaging, metabolic evaluations, skeletal muscle biopsies, mitochondrial biochemical and molecular testing. Permission for publication was given by the families. Muscle histology revealed nonspecific changes, with no ragged red or blue or COX-negative fibers. Sequencing of the mitochondrial DNA indicated patient 2 to be homoplasmic in muscle for the mt.10158T>C mutation in the ND3 subunit and Patient 1 to be 75% heteroplasmic for the mt.10191T>C mutation, also in ND3. Bilateral rolandic lesions and epilepsia partialis continua accompanied by suspicion of mitochondrial disease are indications to search for an underlying mutation in the MT-ND3 gene.
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41
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Lim BC, Park JD, Hwang H, Kim KJ, Hwang YS, Chae JH, Cheon JE, Kim IO, Lee R, Moon HK. Mutations in ND subunits of complex I are an important genetic cause of childhood mitochondrial encephalopathies. J Child Neurol 2009; 24:828-32. [PMID: 19617458 DOI: 10.1177/0883073808331085] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
An increasing number of reports on mitochondrial DNA coding regions' mutations, especially in mitochondrial DNA- encoded NADH dehydrogenase (ND) subunit genes of the respiratory chain complex I, have been published recently, making it possible to improve the molecular diagnosis of many mitochondrial diseases in children with variable clinical features. This article describes 2 mitochondrial DNA mutations in the ND3 and ND5 genes in patients showing clinical features of mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS)/Leigh syndrome overlap syndrome and atypical Leigh syndrome. These cases add to the increasing number of reports stating that mitochondrial DNA-encoded protein-coding regions are mutation hot spots in pediatric patients with encephalopathies with variable clinical spectra.
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Affiliation(s)
- Byung Chan Lim
- Department of Pediatrics, Seoul National University College of Medicine, Seoul, Korea
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42
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Mitochondrial ND3 as the novel causative gene for Leber hereditary optic neuropathy and dystonia. Neurogenetics 2009; 10:337-45. [PMID: 19458970 DOI: 10.1007/s10048-009-0194-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2008] [Accepted: 04/17/2009] [Indexed: 10/20/2022]
Abstract
Leber hereditary optic neuropathy and dystonia (LDYT) is a mitochondrial disorder associated with variable combinations of vision loss and progressive generalized dystonia. LDYT is a unique oxidative phosphorylation disorder caused by mutations in mitochondrial ND6 or ND4 gene. In this paper, we describe a Chinese family with 18 LDYT patients. The comprehensive nucleotide sequence analysis of the entire mitochondrial genome using resequencing microarray revealed a mutation (mtND3*10197A (m.10197G>A)) substituting a threonine for a highly conserved alanine at codon 47 of MTND3 on the background of haplogroup D4b. Quantitative analysis of the heteroplasmy of the mutation revealed a homoplasmy in the leukocytes of all the affected individuals on the maternal side. This is the first description of the ND3 mutation causing LDYT. The mtND3*10197A (m.10197G>A) mutation has recently been described in French and Korean patients with Leigh syndrome. These findings suggest that the clinical presentations associated with the mtND3*10197A (m.10197G>A) mutation (ND3) are much wider, encompassing those of LDYT and Leigh syndrome.
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43
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Kudin AP, Zsurka G, Elger CE, Kunz WS. Mitochondrial involvement in temporal lobe epilepsy. Exp Neurol 2009; 218:326-32. [PMID: 19268667 DOI: 10.1016/j.expneurol.2009.02.014] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2008] [Revised: 02/13/2009] [Accepted: 02/19/2009] [Indexed: 10/21/2022]
Abstract
Mitochondrial dysfunction has been identified as a potential cause of epileptic seizures and therapy-resistant forms of severe epilepsy. Thus, a broad variety of mutation in mitochondrial DNA or nuclear genes leading to the impairment of mitochondrial respiratory chain or of mitochondrial ATP synthesis has been associated with epileptic phenotypes. Additionally, with a variety of different methods impaired mitochondrial function has been reported for the seizure focus of patients with temporal lobe epilepsy and Ammon's horn sclerosis and of animal models of temporal lobe epilepsy. Since mitochondrial oxidative phosphorylation provides the major source of ATP in neurons and mitochondria participate in cellular Ca(2+) homeostasis, their dysfunction strongly affects neuronal excitability and synaptic transmission, which is proposed to be highly relevant for seizure generation. Additionally, mitochondrial dysfunction is known to trigger neuronal cell death, which is a prominent feature of therapy-resistant temporal lobe epilepsy. Therefore, mitochondria have to be considered as promising targets for neuroprotective strategies in epilepsy.
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Affiliation(s)
- Alexei P Kudin
- Department of Epileptology, University Bonn Medical Center, Germany
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44
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Zickermann V, Kerscher S, Zwicker K, Tocilescu MA, Radermacher M, Brandt U. Architecture of complex I and its implications for electron transfer and proton pumping. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2009; 1787:574-83. [PMID: 19366614 DOI: 10.1016/j.bbabio.2009.01.012] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2008] [Revised: 01/15/2009] [Accepted: 01/15/2009] [Indexed: 11/27/2022]
Abstract
Proton pumping NADH:ubiquinone oxidoreductase (complex I) is the largest and remains by far the least understood enzyme complex of the respiratory chain. It consists of a peripheral arm harbouring all known redox active prosthetic groups and a membrane arm with a yet unknown number of proton translocation sites. The ubiquinone reduction site close to iron-sulfur cluster N2 at the interface of the 49-kDa and PSST subunits has been mapped by extensive site directed mutagenesis. Independent lines of evidence identified electron transfer events during reduction of ubiquinone to be associated with the potential drop that generates the full driving force for proton translocation with a 4H(+)/2e(-) stoichiometry. Electron microscopic analysis of immuno-labelled native enzyme and of a subcomplex lacking the electron input module indicated a distance of 35-60 A of cluster N2 to the membrane surface. Resolution of the membrane arm into subcomplexes showed that even the distal part harbours subunits that are prime candidates to participate in proton translocation because they are homologous to sodium/proton antiporters and contain conserved charged residues in predicted transmembrane helices. The mechanism of redox linked proton translocation by complex I is largely unknown but has to include steps where energy is transmitted over extremely long distances. In this review we compile the available structural information on complex I and discuss implications for complex I function.
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Affiliation(s)
- Volker Zickermann
- Goethe-Universität, Fachbereich Medizin, Molekulare Bioenergetik, ZBC, Theodor-Stern-Kai 7, Haus 26, D-60590 Frankfurt am Main, Germany
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45
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Naess K, Freyer C, Bruhn H, Wibom R, Malm G, Nennesmo I, von Döbeln U, Larsson NG. MtDNA mutations are a common cause of severe disease phenotypes in children with Leigh syndrome. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2008; 1787:484-90. [PMID: 19103152 DOI: 10.1016/j.bbabio.2008.11.014] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2008] [Revised: 11/25/2008] [Accepted: 11/26/2008] [Indexed: 10/21/2022]
Abstract
Leigh syndrome is a common clinical manifestation in children with mitochondrial disease and other types of inborn errors of metabolism. We characterised clinical symptoms, prognosis, respiratory chain function and performed extensive genetic analysis of 25 Swedish children suffering from Leigh syndrome with the aim to obtain insights into the molecular pathophysiology and to provide a rationale for genetic counselling. We reviewed the clinical history of all patients and used muscle biopsies in order to perform molecular, biochemical and genetic investigations, including sequencing the entire mitochondrial DNA (mtDNA), the mitochondrial DNA polymerase (POLGA) gene and the surfeit locus protein 1 (SURF1) gene. Respiratory chain enzyme activity measurements identified five patients with isolated complex I deficiency and five with combined enzyme deficiencies. No patient presented with isolated complex IV deficiency. Seven patients had a decreased ATP production rate. Extensive sequence analysis identified eight patients with pathogenic mtDNA mutations and one patient with mutations in POLGA. Mutations of mtDNA are a common cause of LS and mtDNA analysis should always be included in the diagnosis of LS patients, whereas SURF1 mutations are not a common cause of LS in Sweden. Unexpectedly, age of onset, clinical symptoms and prognosis did not reveal any clear differences in LS patients with mtDNA or nuclear DNA mutations.
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Affiliation(s)
- Karin Naess
- Department of Clinical Sciences, Karolinska University Hospital, S-141 86 Stockholm, Sweden
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46
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Finsterer J. Cognitive decline as a manifestation of mitochondrial disorders (mitochondrial dementia). J Neurol Sci 2008; 272:20-33. [DOI: 10.1016/j.jns.2008.05.011] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2007] [Revised: 05/18/2008] [Accepted: 05/20/2008] [Indexed: 11/28/2022]
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47
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Galkin A, Meyer B, Wittig I, Karas M, Schägger H, Vinogradov A, Brandt U. Identification of the mitochondrial ND3 subunit as a structural component involved in the active/deactive enzyme transition of respiratory complex I. J Biol Chem 2008; 283:20907-13. [PMID: 18502755 PMCID: PMC2475694 DOI: 10.1074/jbc.m803190200] [Citation(s) in RCA: 124] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2008] [Revised: 05/23/2008] [Indexed: 12/30/2022] Open
Abstract
Mitochondrial complex I (NADH:ubiquinone oxidoreductase) undergoes reversible deactivation upon incubation at 30-37 degrees C. The active/deactive transition could play an important role in the regulation of complex I activity. It has been suggested recently that complex I may become modified by S-nitrosation under pathological conditions during hypoxia or when the nitric oxide:oxygen ratio increases. Apparently, a specific cysteine becomes accessible to chemical modification only in the deactive form of the enzyme. By selective fluorescence labeling and proteomic analysis, we have identified this residue as cysteine-39 of the mitochondrially encoded ND3 subunit of bovine heart mitochondria. Cysteine-39 is located in a loop connecting the first and second transmembrane helix of this highly hydrophobic subunit. We propose that this loop connects the ND3 subunit of the membrane arm with the PSST subunit of the peripheral arm of complex I, placing it in a region that is known to be critical for the catalytic mechanism of complex I. In fact, mutations in three positions of the loop were previously reported to cause Leigh syndrome with and without dystonia or progressive mitochondrial disease.
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Affiliation(s)
- Alexander Galkin
- Molecular Bioenergetics Group, Cluster of
Excellence Frankfurt “Macromolecular complexes,” Medical School,
Johann Wolfgang Goethe-Universität, Theodor-Stern-Kai 7, D-60590
Frankfurt am Main, Germany, the Institut
für Pharmazeutische Chemie, Cluster of Excellence Frankfurt
“Macromolecular complexes,” Johann Wolfgang
Goethe-Universität, Max-von-Laue Str.-9, D-60438 Frankfurt am Main,
Germany, and the Department of Biochemistry,
School of Biology, Moscow State University, Moscow 119992, Russian
Federation
| | - Björn Meyer
- Molecular Bioenergetics Group, Cluster of
Excellence Frankfurt “Macromolecular complexes,” Medical School,
Johann Wolfgang Goethe-Universität, Theodor-Stern-Kai 7, D-60590
Frankfurt am Main, Germany, the Institut
für Pharmazeutische Chemie, Cluster of Excellence Frankfurt
“Macromolecular complexes,” Johann Wolfgang
Goethe-Universität, Max-von-Laue Str.-9, D-60438 Frankfurt am Main,
Germany, and the Department of Biochemistry,
School of Biology, Moscow State University, Moscow 119992, Russian
Federation
| | - Ilka Wittig
- Molecular Bioenergetics Group, Cluster of
Excellence Frankfurt “Macromolecular complexes,” Medical School,
Johann Wolfgang Goethe-Universität, Theodor-Stern-Kai 7, D-60590
Frankfurt am Main, Germany, the Institut
für Pharmazeutische Chemie, Cluster of Excellence Frankfurt
“Macromolecular complexes,” Johann Wolfgang
Goethe-Universität, Max-von-Laue Str.-9, D-60438 Frankfurt am Main,
Germany, and the Department of Biochemistry,
School of Biology, Moscow State University, Moscow 119992, Russian
Federation
| | - Michael Karas
- Molecular Bioenergetics Group, Cluster of
Excellence Frankfurt “Macromolecular complexes,” Medical School,
Johann Wolfgang Goethe-Universität, Theodor-Stern-Kai 7, D-60590
Frankfurt am Main, Germany, the Institut
für Pharmazeutische Chemie, Cluster of Excellence Frankfurt
“Macromolecular complexes,” Johann Wolfgang
Goethe-Universität, Max-von-Laue Str.-9, D-60438 Frankfurt am Main,
Germany, and the Department of Biochemistry,
School of Biology, Moscow State University, Moscow 119992, Russian
Federation
| | - Hermann Schägger
- Molecular Bioenergetics Group, Cluster of
Excellence Frankfurt “Macromolecular complexes,” Medical School,
Johann Wolfgang Goethe-Universität, Theodor-Stern-Kai 7, D-60590
Frankfurt am Main, Germany, the Institut
für Pharmazeutische Chemie, Cluster of Excellence Frankfurt
“Macromolecular complexes,” Johann Wolfgang
Goethe-Universität, Max-von-Laue Str.-9, D-60438 Frankfurt am Main,
Germany, and the Department of Biochemistry,
School of Biology, Moscow State University, Moscow 119992, Russian
Federation
| | - Andrei Vinogradov
- Molecular Bioenergetics Group, Cluster of
Excellence Frankfurt “Macromolecular complexes,” Medical School,
Johann Wolfgang Goethe-Universität, Theodor-Stern-Kai 7, D-60590
Frankfurt am Main, Germany, the Institut
für Pharmazeutische Chemie, Cluster of Excellence Frankfurt
“Macromolecular complexes,” Johann Wolfgang
Goethe-Universität, Max-von-Laue Str.-9, D-60438 Frankfurt am Main,
Germany, and the Department of Biochemistry,
School of Biology, Moscow State University, Moscow 119992, Russian
Federation
| | - Ulrich Brandt
- Molecular Bioenergetics Group, Cluster of
Excellence Frankfurt “Macromolecular complexes,” Medical School,
Johann Wolfgang Goethe-Universität, Theodor-Stern-Kai 7, D-60590
Frankfurt am Main, Germany, the Institut
für Pharmazeutische Chemie, Cluster of Excellence Frankfurt
“Macromolecular complexes,” Johann Wolfgang
Goethe-Universität, Max-von-Laue Str.-9, D-60438 Frankfurt am Main,
Germany, and the Department of Biochemistry,
School of Biology, Moscow State University, Moscow 119992, Russian
Federation
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48
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Bannwarth S, Procaccio V, Rouzier C, Fragaki K, Poole J, Chabrol B, Desnuelle C, Pouget J, Azulay JP, Attarian S, Pellissier JF, Gargus JJ, Abdenur JE, Mozaffar T, Calvas P, Labauge P, Pages M, Wallace DC, Lambert JC, Paquis-Flucklinger V. Rapid identification of mitochondrial DNA (mtDNA) mutations in neuromuscular disorders by using surveyor strategy. Mitochondrion 2007; 8:136-45. [PMID: 18078792 DOI: 10.1016/j.mito.2007.10.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2007] [Revised: 10/22/2007] [Accepted: 10/26/2007] [Indexed: 11/18/2022]
Abstract
Mutations of mitochondrial genome are responsible for respiratory chain defects in numerous patients. We have used a strategy, based on the use of a mismatch-specific DNA endonuclease named " Surveyor Nuclease", for screening the entire mtDNA in a group of 50 patients with neuromuscular features, suggesting a respiratory chain dysfunction. We identified mtDNA mutations in 20% of patients (10/50). Among the identified mutations, four are not found in any mitochondrial database and have not been reported previously. We also confirm that mtDNA polymorphisms are frequently found in a heteroplasmic state (15 different polymorphisms were identified among which five were novel).
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Affiliation(s)
- S Bannwarth
- Department of Medical Genetics, Archet 2 Hospital, CHU Nice, France
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49
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Chae JH, Lee JS, Kim KJ, Hwang YS, Bonilla E, Tanji K, Hirano M. A novel ND3 mitochondrial DNA mutation in three Korean children with basal ganglia lesions and complex I deficiency. Pediatr Res 2007; 61:622-4. [PMID: 17413873 DOI: 10.1203/pdr.0b013e3180459f2d] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Mitochondrial disorders have notoriously variable clinical presentations, particularly in children. A growing number of reports describe mutations in the mitochondrial DNA (mtDNA)-encoded subunits of complex I (EC 1.6.5.3) causing early-onset encephalopathy. Here, we describe two Korean siblings with childhood-onset progressive generalized dystonia and one Korean child with strokelike episodes in infancy; all three had bilateral lesions of the basal ganglia and partial deficiencies of complex I. Analysis of their mtDNA revealed a novel heteroplasmic m.10197G>A mutation (A47T) in the ND3 (NADH dehydrogenase subunit 3) gene. This study underscores the importance of screening mtDNA-encoded respiratory chain structural genes, including ND3, in pediatric patients with unexplained encephalopathies.
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Affiliation(s)
- Jong Hee Chae
- Department of Neurology, Columbia University College of Physicians and Surgeons, New York, New York 10032, USA
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50
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Sarzi E, Brown MD, Lebon S, Chretien D, Munnich A, Rotig A, Procaccio V. A novel recurrent mitochondrial DNA mutation in ND3 gene is associated with isolated complex I deficiency causing Leigh syndrome and dystonia. Am J Med Genet A 2007; 143A:33-41. [PMID: 17152068 DOI: 10.1002/ajmg.a.31565] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Defects in NADH:ubiquinone oxidoreductase (complex I), the largest complex of the mitochondrial respiratory chain, account for most cases of respiratory chain deficiency in human. Complex I contains at least 45 subunits, 7 of which are encoded by mitochondrial DNA (mtDNA). Here we report a novel 10197G>A mutation of the ND3 gene in three unrelated families with Leigh syndrome (LS) or dystonia. Variable degrees of heteroplasmy were found in all tissues tested and a high percentage of mutant mtDNA was observed in muscle. The 10197G>A mutation modifies a hydrophobic alanine residue into a hydrophilic threonine (A47T) in a highly conserved domain of ND3 subunit. Furthermore, this defect could be transferred along with the mutant mtDNAs to rho degrees lymphoblastoid cells in cybrid experiments. However, nuclear modifier genes may also play a role in the phenotypic expression and severity of the 10197G>A mutation. The association of the 10197G>A ND3 mutation with an isolated biochemical defect involving complex I and the discovery of the 10197G>A mutation with a similar phenotype in three unrelated families establish its pathogenicity and demonstrate that the amino acid position A47 is important for the function of complex I. These results show that the 10197G>A mutation in the mitochondrial ND3 gene should be considered as a common mtDNA mutation responsible for LS and dystonia.
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Affiliation(s)
- Emmanuelle Sarzi
- INSERM U781, Department of Genetics, Hôpital Necker-Enfants Malades, Paris, France
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