1
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Thompson K, Stroud DA, Thorburn DR, Taylor RW. Investigation of oxidative phosphorylation activity and complex composition in mitochondrial disease. HANDBOOK OF CLINICAL NEUROLOGY 2023; 194:127-139. [PMID: 36813309 DOI: 10.1016/b978-0-12-821751-1.00008-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
A multidisciplinary approach to the laboratory diagnosis of mitochondrial disease has long been applied, with crucial information provided by deep clinical phenotyping, blood investigations, and biomarker screening as well as histopathological and biochemical testing of biopsy material to support molecular genetic screening. In an era of second and third generation sequencing technologies, traditional diagnostic algorithms for mitochondrial disease have been replaced by gene agnostic, genomic strategies including whole-exome sequencing (WES) and whole-genome sequencing (WGS), increasingly supported by other 'omics technologies (Alston et al., 2021). Whether a primary testing strategy, or one used to validate and interpret candidate genetic variants, the availability of a range of tests aimed at determining mitochondrial function (i.e., the assessment of individual respiratory chain enzyme activities in a tissue biopsy or cellular respiration in a patient cell line) remains an important part of the diagnostic armory. In this chapter, we summarize several disciplines used in the laboratory investigation of suspected mitochondrial disease, including the histopathological and biochemical assessment of mitochondrial function, as well as protein-based techniques to assess the steady-state levels of oxidative phosphorylation (OXPHOS) subunits and assembly of OXPHOS complexes via traditional (immunoblotting) and cutting-edge (quantitative proteomic) approaches.
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Affiliation(s)
- Kyle Thompson
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - David A Stroud
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, VIC, Australia; Brain and Mitochondrial Research Group, Murdoch Children's Research Institute, Melbourne, VIC, Australia
| | - David R Thorburn
- Brain and Mitochondrial Research Group, Murdoch Children's Research Institute, Melbourne, VIC, Australia; Department of Paediatrics, University of Melbourne, Melbourne, VIC, Australia; Mitochondrial Laboratory, Victorian Clinical Genetic Services, Melbourne, VIC, Australia
| | - Robert W Taylor
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom; NHS Highly Specialised Services for Rare Mitochondrial Disorders, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, United Kingdom.
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2
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Xu Q, Sun P, Feng C, Chen Q, Sun X, Chen Y, Tian G. Varying Clinical Phenotypes of Mitochondrial DNA T12811C Mutation: A Case Series Report. Front Med (Lausanne) 2022; 9:912103. [PMID: 35860740 PMCID: PMC9291510 DOI: 10.3389/fmed.2022.912103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Accepted: 06/13/2022] [Indexed: 11/18/2022] Open
Abstract
The T12811C mitochondrial DNA (mtDNA) mutation has been reported in Leber hereditary optic neuropathy (LHON) previously, with vision loss as the main manifestation. The involvement of other organ systems, including the central and peripheral nervous system, heart, and extraocular muscles, has not been well described. This case series report investigated four patients with T12811C mtDNA mutation, verified through a next generation sequencing. Two male patients presented with bilateral subacute visual decrease combined with involvement of multiple organ systems: leukoencephalopathy, hypertrophic cardiomyopathy, neurosensory deafness, spinal cord lesion and peripheral neuropathies. Two female patients presented with progressive ptosis and ophthalmoplegia, one of whom also manifested optic atrophy. This study found out that patients harboring T12811C mtDNA mutation manifested not only as vision loss, but also as a multi-system disorder affecting the nervous system, heart, and extraocular muscles.
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Affiliation(s)
- Qingdan Xu
- Department of Ophthalmology, Eye and ENT Hospital, Fudan University, Shanghai, China
| | - Ping Sun
- Department of Ophthalmology, Eye and ENT Hospital, Fudan University, Shanghai, China
| | - Chaoyi Feng
- NHC Key Laboratory of Myopia, Chinese Academy of Medical Sciences, and Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China
| | - Qian Chen
- NHC Key Laboratory of Myopia, Chinese Academy of Medical Sciences, and Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China
| | - Xinghuai Sun
- Department of Ophthalmology, Eye and ENT Hospital, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia, Chinese Academy of Medical Sciences, and Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China
- State Key Laboratory of Medical Neurobiology, Institute of Brain Science, Fudan University, Shanghai, China
| | - Yuhong Chen
- Department of Ophthalmology, Eye and ENT Hospital, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia, Chinese Academy of Medical Sciences, and Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China
- *Correspondence: Yuhong Chen,
| | - Guohong Tian
- Department of Ophthalmology, Eye and ENT Hospital, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia, Chinese Academy of Medical Sciences, and Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China
- Guohong Tian,
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3
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Montanari A. In Vivo Analysis of Mitochondrial Protein Synthesis in Saccharomyces cerevisiae Mitochondrial tRNA Mutants. Methods Mol Biol 2022; 2497:243-254. [PMID: 35771446 DOI: 10.1007/978-1-0716-2309-1_15] [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] [Indexed: 06/15/2023]
Abstract
I describe here a protocol for the analysis of mitochondrial protein synthesis as a useful tool to characterize the mitochondrial defects associated with mutations in mitochondrial tRNA genes. The yeast Saccharomyces cerevisiae mutants, bearing human equivalent pathogenic mutations, were used as a simple model for analysis. The mitochondrial proteins were labeled by L[35S]-methionine incorporation in growing cells, extracted from purified mitochondria, and fractionated by SDS-polyacrylamide gel electrophoresis followed by autoradiography. By this method, it is possible to distinguish different protein synthesis profiles in the analyzed mitochondrial tRNA mutants.
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Affiliation(s)
- Arianna Montanari
- Department of Biology and Biotechnologies "Charles Darwin", Sapienza University of Rome, Rome, Italy.
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4
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Peng J, Ramatchandirin B, Pearah A, Maheshwari A, He L. Development and Functions of Mitochondria in Early Life. NEWBORN (CLARKSVILLE, MD.) 2022; 1:131-141. [PMID: 37206110 PMCID: PMC10193534 DOI: 10.5005/jp-journals-11002-0013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Mitochondria are highly dynamic organelles of bacterial origin in eukaryotic cells. These play a central role in metabolism and adenosine triphosphate (ATP) synthesis and in the production and regulation of reactive oxygen species (ROS). In addition to the generation of energy, mitochondria perform numerous other functions to support key developmental events such as fertilization during reproduction, oocyte maturation, and the development of the embryo. During embryonic and neonatal development, mitochondria may have important effects on metabolic, energetic, and epigenetic regulation, which may have significant short- and long-term effects on embryonic and offspring health. Hence, the environment, epigenome, and early-life regulation are all linked by mitochondrial integrity, communication, and metabolism.
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Affiliation(s)
- Jinghua Peng
- Institute of Liver Diseases, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Balamurugan Ramatchandirin
- Department of Pediatrics and Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Alexia Pearah
- Department of Pediatrics and Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Akhil Maheshwari
- Global Newborn Society, Clarksville, Maryland, United States of America
| | - Ling He
- Department of Pediatrics and Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
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5
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Cowell W, Brunst K, Colicino E, Zhang L, Zhang X, Bloomquist TR, Baccarelli AA, Wright RJ. Placental mitochondrial DNA mutational load and perinatal outcomes: Findings from a multi-ethnic pregnancy cohort. Mitochondrion 2021; 59:267-275. [PMID: 34102325 DOI: 10.1016/j.mito.2021.06.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 05/07/2021] [Accepted: 06/03/2021] [Indexed: 10/21/2022]
Abstract
Mitochondria fuel placental activity, with mitochondrial dysfunction implicated in several perinatal complications. We investigated placental mtDNA mutational load using NextGen sequencing in relation to birthweight and gestational length among 358 mother-newborn pairs. We found that higher heteroplasmy, especially in the hypervariable displacement loop region, was associated with shorter gestational length. Results were similar among male and female pregnancies, but stronger in magnitude among females. With regard to growth, we observed that higher mutational load was associated with lower birthweight-for-gestational age (BWGA) among females, but higher BWGA among males. These findings support potential sex-differential fetal biological strategies for coping with increased heteroplasmies.
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Affiliation(s)
- Whitney Cowell
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
| | - Kelly Brunst
- Department of Environmental and Public Health Sciences, University of Cincinnati, College of Medicine, Cincinnati, OH 45267, USA
| | - Elena Colicino
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Li Zhang
- Department of Environmental and Public Health Sciences, University of Cincinnati, College of Medicine, Cincinnati, OH 45267, USA
| | - Xiang Zhang
- Department of Environmental and Public Health Sciences, University of Cincinnati, College of Medicine, Cincinnati, OH 45267, USA
| | - Tessa R Bloomquist
- Department of Environmental Health Sciences, Columbia University Mailman School of Public Health, New York, NY 10032, USA
| | - Andrea A Baccarelli
- Department of Environmental Health Sciences, Columbia University Mailman School of Public Health, New York, NY 10032, USA
| | - Rosalind J Wright
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Kravis Children's Hospital, Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Institute for Exposomic Research, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
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6
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Human Mitoribosome Biogenesis and Its Emerging Links to Disease. Int J Mol Sci 2021; 22:ijms22083827. [PMID: 33917098 PMCID: PMC8067846 DOI: 10.3390/ijms22083827] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 03/23/2021] [Accepted: 03/24/2021] [Indexed: 12/20/2022] Open
Abstract
Mammalian mitochondrial ribosomes (mitoribosomes) synthesize a small subset of proteins, which are essential components of the oxidative phosphorylation machinery. Therefore, their function is of fundamental importance to cellular metabolism. The assembly of mitoribosomes is a complex process that progresses through numerous maturation and protein-binding events coordinated by the actions of several assembly factors. Dysregulation of mitoribosome production is increasingly recognized as a contributor to metabolic and neurodegenerative diseases. In recent years, mutations in multiple components of the mitoribosome assembly machinery have been associated with a range of human pathologies, highlighting their importance to cell function and health. Here, we provide a review of our current understanding of mitoribosome biogenesis, highlighting the key factors involved in this process and the growing number of mutations in genes encoding mitoribosomal RNAs, proteins, and assembly factors that lead to human disease.
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7
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Ferrari A, Del'Olio S, Barrientos A. The Diseased Mitoribosome. FEBS Lett 2020; 595:1025-1061. [PMID: 33314036 DOI: 10.1002/1873-3468.14024] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 12/03/2020] [Accepted: 12/06/2020] [Indexed: 12/17/2022]
Abstract
Mitochondria control life and death in eukaryotic cells. Harboring a unique circular genome, a by-product of an ancient endosymbiotic event, mitochondria maintains a specialized and evolutionary divergent protein synthesis machinery, the mitoribosome. Mitoribosome biogenesis depends on elements encoded in both the mitochondrial genome (the RNA components) and the nuclear genome (all ribosomal proteins and assembly factors). Recent cryo-EM structures of mammalian mitoribosomes have illuminated their composition and provided hints regarding their assembly and elusive mitochondrial translation mechanisms. A growing body of literature involves the mitoribosome in inherited primary mitochondrial disorders. Mutations in genes encoding mitoribosomal RNAs, proteins, and assembly factors impede mitoribosome biogenesis, causing protein synthesis defects that lead to respiratory chain failure and mitochondrial disorders such as encephalo- and cardiomyopathy, deafness, neuropathy, and developmental delays. In this article, we review the current fundamental understanding of mitoribosome assembly and function, and the clinical landscape of mitochondrial disorders driven by mutations in mitoribosome components and assembly factors, to portray how basic and clinical studies combined help us better understand both mitochondrial biology and medicine.
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Affiliation(s)
- Alberto Ferrari
- Department of Neurology, University of Miami Miller School of Medicine, FL, USA
| | - Samuel Del'Olio
- Department of Neurology, University of Miami Miller School of Medicine, FL, USA.,Molecular and Cellular Pharmacology Graduate Program, University of Miami Miller School of Medicine, FL, USA
| | - Antoni Barrientos
- Department of Neurology, University of Miami Miller School of Medicine, FL, USA.,Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, FL, USA
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8
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Fay A, Garcia Y, Margeta M, Maharjan S, Jürgensen C, Briceño J, Garcia M, Yin S, Bassaganyas L, McMahon T, Hou YM, Fu YH, Ptáček LJ. A Mitochondrial tRNA Mutation Causes Axonal CMT in a Large Venezuelan Family. Ann Neurol 2020; 88:830-842. [PMID: 32715519 DOI: 10.1002/ana.25854] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 07/20/2020] [Accepted: 07/22/2020] [Indexed: 12/19/2022]
Abstract
OBJECTIVE The objective of this study was to identify the genetic cause for progressive peripheral nerve disease in a Venezuelan family. Despite the growing list of genes associated with Charcot-Marie-Tooth disease, many patients with axonal forms lack a genetic diagnosis. METHODS A pedigree was constructed, based on family clinical data. Next-generation sequencing of mitochondrial DNA (mtDNA) was performed for 6 affected family members. Muscle biopsies from 4 family members were used for analysis of muscle histology and ultrastructure, mtDNA sequencing, and RNA quantification. Ultrastructural studies were performed on sensory nerve biopsies from 2 affected family members. RESULTS Electrodiagnostic testing showed a motor and sensory axonal polyneuropathy. Pedigree analysis revealed inheritance only through the maternal line, consistent with mitochondrial transmission. Sequencing of mtDNA identified a mutation in the mitochondrial tRNAVal (mt-tRNAVal ) gene, m.1661A>G, present at nearly 100% heteroplasmy, which disrupts a Watson-Crick base pair in the T-stem-loop. Muscle biopsies showed chronic denervation/reinnervation changes, whereas biochemical analysis of electron transport chain (ETC) enzyme activities showed reduction in multiple ETC complexes. Northern blots from skeletal muscle total RNA showed severe reduction in abundance of mt-tRNAVal , and mildly increased mt-tRNAPhe , in subjects compared with unrelated age- and sex-matched controls. Nerve biopsies from 2 affected family members demonstrated ultrastructural mitochondrial abnormalities (hyperplasia, hypertrophy, and crystalline arrays) consistent with a mitochondrial neuropathy. CONCLUSION We identify a previously unreported cause of Charcot-Marie-Tooth (CMT) disease, a mutation in the mt-tRNAVal , in a Venezuelan family. This work expands the list of CMT-associated genes from protein-coding genes to a mitochondrial tRNA gene. ANN NEUROL 2020;88:830-842.
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Affiliation(s)
- Alexander Fay
- Department of Neurology, University of California, San Francisco, CA, USA
| | - Yngo Garcia
- Department of Biochemistry, Faculty of Medicine, University of The Andes, Mérida, Venezuela.,Unit of Surgery, Neurosurgery Service, Medical Surgery Clinical Institute, Mérida, Venezuela
| | - Marta Margeta
- Department of Pathology, University of California, San Francisco, CA, USA
| | - Sunita Maharjan
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Claudia Jürgensen
- Department of Biology, Faculty of Science, University of The Andes, Mérida, Venezuela
| | - Jose Briceño
- Physiotherapy and Rehabilitation Service, University Hospital of The Andes, Mérida, Venezuela
| | - Mariaelena Garcia
- Department of Biology, Faculty of Science, University of The Andes, Mérida, Venezuela
| | - Sitao Yin
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Laia Bassaganyas
- Department of Medical Genetics, University of Cambridge and Cardiovascular Research Institute, University of California, San Francisco, CA, USA
| | - Thomas McMahon
- Department of Neurology, University of California, San Francisco, CA, USA
| | - Ya-Ming Hou
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Ying-Hui Fu
- Department of Neurology, University of California, San Francisco, CA, USA
| | - Louis J Ptáček
- Department of Neurology, University of California, San Francisco, CA, USA
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9
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Hagen CM, Elson JL, Hedley PL, Aidt FH, Havndrup O, Jensen MK, Kanters JK, Atherton JJ, McGaughran J, Bundgaard H, Christiansen M. Evolutionary dissection of mtDNA hg H: a susceptibility factor for hypertrophic cardiomyopathy. Mitochondrial DNA A DNA Mapp Seq Anal 2020; 31:238-244. [PMID: 32602800 DOI: 10.1080/24701394.2020.1782897] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Mitochondrial DNA (mtDNA) haplogroup (hg) H has been reported as a susceptibility factor for hypertrophic cardiomyopathy (HCM). This was established in genetic association studies, however, the SNP or SNP's that are associated with the increased risk have not been identified. Hg H is the most frequent European mtDNA hg with greater than 80 subhaplogroups (subhgs) each defined by specific SNPs. We tested the hypothesis that the distribution of H subhgs might differ between HCM patients and controls. The subhg H distribution in 55 HCM index cases was compared to that of two Danish mtDNA hg H control groups (n = 170 and n = 908, respectively). In the HCM group, H and 12 different H subhgs were found. All these, except subhgs H73, were also found in both control groups. The HCM group was also characterized by a higher proportion of H3 compared to H2. In the HCM group the H3/H2 proportion was 1.7, whereas it was 0.45 and 0.54 in the control groups. This tendency was replicated in an independent group of Hg H HCM index cases (n = 39) from Queensland, Australia, where the H3/H2 ratio was 1.5. In conclusion, the H subhgs distribution differs between HCM cases and controls, but the difference is subtle, and the understanding of the pathogenic significance is hampered by the lack of functional studies on the subhgs of H.
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Affiliation(s)
- Christian M Hagen
- Department for Congenital Disorders, Statens Serum Institute, Copenhagen, Denmark.,Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Joanna L Elson
- Department for Congenital Disorders, Statens Serum Institute, Copenhagen, Denmark.,Biosciences Institute, Newcastle University, Newcastle upon Tyne, UK
| | - Paula L Hedley
- Department for Congenital Disorders, Statens Serum Institute, Copenhagen, Denmark
| | - Frederik H Aidt
- Department for Congenital Disorders, Statens Serum Institute, Copenhagen, Denmark
| | - Ole Havndrup
- Department of Cardiology, Roskilde Hospital, Roskilde, Denmark
| | - Morten K Jensen
- Department of Medicine B, The Heart Center, Copenhagen, Denmark
| | - Jørgen K Kanters
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - John J Atherton
- Department of Cardiology, Royal Brisbane Hospital and School of Medicine, University of Queensland, Brisbane, Australia
| | - Julie McGaughran
- Queensland Clinical Genetics Service, Royal Children's Hospital and School of Medicine, Brisbane, Australia
| | | | - Michael Christiansen
- Department for Congenital Disorders, Statens Serum Institute, Copenhagen, Denmark.,Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
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10
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Wong LJC, Chen T, Schmitt ES, Wang J, Zhang S, Landsverk M, Li F, Tang S, Wang Y, Zhang VW, Craigen WJ. Response to Bai et al. Genet Med 2020; 22:1420-1421. [PMID: 32418988 DOI: 10.1038/s41436-020-0805-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Accepted: 03/31/2020] [Indexed: 11/09/2022] Open
Affiliation(s)
- Lee-Jun C Wong
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA. .,Baylor Genetics Laboratory, Houston, TX, USA.
| | - Ting Chen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.,Department of Endocrinology, Genetics and Metabolism, Children's Hospital of Soochow University, Suzhou, China
| | - Eric S Schmitt
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.,Baylor Genetics Laboratory, Houston, TX, USA
| | - Jing Wang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.,Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Shulin Zhang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.,Department of Pathology and Laboratory Medicine, UKHealthCare, University of Kentucky, Lexington, USA
| | - Megan Landsverk
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.,Global Laboratory Services/Diagnostics, Perkin Elmer, Waltham, MA, USA
| | - Fangyuan Li
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.,Sema4, Branford, CT, USA
| | - Sha Tang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.,WuXi NextCODE, Cambridge, MA, USA
| | - Yue Wang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.,Baylor Genetics Laboratory, Houston, TX, USA
| | - Victor Wei Zhang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.,AmCare Genomics Lab, Guangzhou, China
| | - William J Craigen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.,Baylor Genetics Laboratory, Houston, TX, USA
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11
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Two Women One Baby: Mitochondrial Replacement Therapy with Medical, Ethical and Legal Aspects. ANADOLU KLINIĞI TIP BILIMLERI DERGISI 2020. [DOI: 10.21673/anadoluklin.673832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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12
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Ma H, Hayama T, Van Dyken C, Darby H, Koski A, Lee Y, Gutierrez NM, Yamada S, Li Y, Andrews M, Ahmed R, Liang D, Gonmanee T, Kang E, Nasser M, Kempton B, Brigande J, McGill TJ, Terzic A, Amato P, Mitalipov S. Deleterious mtDNA mutations are common in mature oocytes. Biol Reprod 2020; 102:607-619. [PMID: 31621839 PMCID: PMC7068114 DOI: 10.1093/biolre/ioz202] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 10/08/2019] [Accepted: 10/15/2019] [Indexed: 12/13/2022] Open
Abstract
Heritable mitochondrial DNA (mtDNA) mutations are common, yet only a few recurring pathogenic mtDNA variants account for the majority of known familial cases in humans. Purifying selection in the female germline is thought to be responsible for the elimination of most harmful mtDNA mutations during oogenesis. Here we show that deleterious mtDNA mutations are abundant in ovulated mature mouse oocytes and preimplantation embryos recovered from PolG mutator females but not in their live offspring. This implies that purifying selection acts not in the maternal germline per se, but during post-implantation development. We further show that oocyte mtDNA mutations can be captured and stably maintained in embryonic stem cells and then reintroduced into chimeras, thereby allowing examination of the effects of specific mutations on fetal and postnatal development.
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Affiliation(s)
- Hong Ma
- Center for Embryonic Cell and Gene Therapy, Oregon Health & Science University, 3303 S.W. Bond Avenue, Portland, Oregon 97239, USA
- Division of Reproductive & Developmental Sciences, Oregon National Primate Research Center, Oregon Health & Science University, 505 N.W. 185th Avenue, Beaverton, Oregon 97006, USA
| | - Tomonari Hayama
- Center for Embryonic Cell and Gene Therapy, Oregon Health & Science University, 3303 S.W. Bond Avenue, Portland, Oregon 97239, USA
- Division of Reproductive & Developmental Sciences, Oregon National Primate Research Center, Oregon Health & Science University, 505 N.W. 185th Avenue, Beaverton, Oregon 97006, USA
| | - Crystal Van Dyken
- Center for Embryonic Cell and Gene Therapy, Oregon Health & Science University, 3303 S.W. Bond Avenue, Portland, Oregon 97239, USA
- Division of Reproductive & Developmental Sciences, Oregon National Primate Research Center, Oregon Health & Science University, 505 N.W. 185th Avenue, Beaverton, Oregon 97006, USA
| | - Hayley Darby
- Center for Embryonic Cell and Gene Therapy, Oregon Health & Science University, 3303 S.W. Bond Avenue, Portland, Oregon 97239, USA
- Division of Reproductive & Developmental Sciences, Oregon National Primate Research Center, Oregon Health & Science University, 505 N.W. 185th Avenue, Beaverton, Oregon 97006, USA
| | - Amy Koski
- Center for Embryonic Cell and Gene Therapy, Oregon Health & Science University, 3303 S.W. Bond Avenue, Portland, Oregon 97239, USA
- Division of Reproductive & Developmental Sciences, Oregon National Primate Research Center, Oregon Health & Science University, 505 N.W. 185th Avenue, Beaverton, Oregon 97006, USA
| | - Yeonmi Lee
- Stem Cell Center, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil Songpa-gu, Seoul 05505, Republic of Korea
| | - Nuria Marti Gutierrez
- Center for Embryonic Cell and Gene Therapy, Oregon Health & Science University, 3303 S.W. Bond Avenue, Portland, Oregon 97239, USA
- Division of Reproductive & Developmental Sciences, Oregon National Primate Research Center, Oregon Health & Science University, 505 N.W. 185th Avenue, Beaverton, Oregon 97006, USA
| | - Satsuki Yamada
- Department of Cardiovascular Medicine, Center for Regenerative Medicine, Mayo Clinic, Rochester, MN 55905, USA
| | - Ying Li
- Center for Embryonic Cell and Gene Therapy, Oregon Health & Science University, 3303 S.W. Bond Avenue, Portland, Oregon 97239, USA
- Division of Reproductive & Developmental Sciences, Oregon National Primate Research Center, Oregon Health & Science University, 505 N.W. 185th Avenue, Beaverton, Oregon 97006, USA
| | - Michael Andrews
- Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, 3375 S.W. Terwilliger Blvd, Portland, Oregon 97239, USA
| | - Riffat Ahmed
- Center for Embryonic Cell and Gene Therapy, Oregon Health & Science University, 3303 S.W. Bond Avenue, Portland, Oregon 97239, USA
- Division of Reproductive & Developmental Sciences, Oregon National Primate Research Center, Oregon Health & Science University, 505 N.W. 185th Avenue, Beaverton, Oregon 97006, USA
| | - Dan Liang
- Center for Embryonic Cell and Gene Therapy, Oregon Health & Science University, 3303 S.W. Bond Avenue, Portland, Oregon 97239, USA
- Division of Reproductive & Developmental Sciences, Oregon National Primate Research Center, Oregon Health & Science University, 505 N.W. 185th Avenue, Beaverton, Oregon 97006, USA
| | - Thanasup Gonmanee
- Center for Embryonic Cell and Gene Therapy, Oregon Health & Science University, 3303 S.W. Bond Avenue, Portland, Oregon 97239, USA
- Division of Reproductive & Developmental Sciences, Oregon National Primate Research Center, Oregon Health & Science University, 505 N.W. 185th Avenue, Beaverton, Oregon 97006, USA
| | - Eunju Kang
- Stem Cell Center, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil Songpa-gu, Seoul 05505, Republic of Korea
| | - Mohammed Nasser
- Center for Embryonic Cell and Gene Therapy, Oregon Health & Science University, 3303 S.W. Bond Avenue, Portland, Oregon 97239, USA
- Division of Reproductive & Developmental Sciences, Oregon National Primate Research Center, Oregon Health & Science University, 505 N.W. 185th Avenue, Beaverton, Oregon 97006, USA
| | - Beth Kempton
- Oregon Hearing Research Center, Oregon Health & Science University, 3181 S.W. Sam Jackson Park Road, Portland, Oregon 97239, USA
| | - John Brigande
- Oregon Hearing Research Center, Oregon Health & Science University, 3181 S.W. Sam Jackson Park Road, Portland, Oregon 97239, USA
| | - Trevor J McGill
- Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, 3375 S.W. Terwilliger Blvd, Portland, Oregon 97239, USA
| | - Andre Terzic
- Department of Cardiovascular Medicine, Center for Regenerative Medicine, Mayo Clinic, Rochester, MN 55905, USA
| | - Paula Amato
- Center for Embryonic Cell and Gene Therapy, Oregon Health & Science University, 3303 S.W. Bond Avenue, Portland, Oregon 97239, USA
- Division of Reproductive Endocrinology, Department of Obstetrics and Gynecology, Oregon Health & Science University, 3181 S.W. Sam Jackson Park Road, Portland, Oregon 97239, USA
| | - Shoukhrat Mitalipov
- Center for Embryonic Cell and Gene Therapy, Oregon Health & Science University, 3303 S.W. Bond Avenue, Portland, Oregon 97239, USA
- Division of Reproductive & Developmental Sciences, Oregon National Primate Research Center, Oregon Health & Science University, 505 N.W. 185th Avenue, Beaverton, Oregon 97006, USA
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13
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Interpretation of mitochondrial tRNA variants. Genet Med 2020; 22:917-926. [PMID: 31965079 DOI: 10.1038/s41436-019-0746-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 12/26/2019] [Indexed: 11/08/2022] Open
Abstract
PURPOSE To develop criteria to interpret mitochondrial transfer RNA (mt-tRNA) variants based on unique characteristics of mitochondrial genetics and conserved structural/functional properties of tRNA. METHODS We developed rules on a set of established pathogenic/benign variants by examining heteroplasmy correlations with phenotype, tissue distribution, family members, and among unrelated families from published literature. We validated these deduced rules using our new cases and applied them to classify novel variants. RESULTS Evaluation of previously reported pathogenic variants found that 80.6% had sufficient evidence to support phenotypic correlation with heteroplasmy levels among and within families. The remaining variants were downgraded due to the lack of similar evidence. Application of the verified criteria resulted in rescoring 80.8% of reported variants of uncertain significance (VUS) to benign and likely benign. Among 97 novel variants, none met pathogenic criteria. A large proportion of novel variants (84.5%) remained as VUS, while only 10.3% were likely pathogenic. Detection of these novel variants in additional individuals would facilitate their classification. CONCLUSION Proper interpretation of mt-tRNA variants is crucial for accurate clinical diagnosis and genetic counseling. Correlations with tissue distribution, heteroplasmy levels, predicted perturbations to tRNA structure, and phenotypes provide important evidence for determining the clinical significance of mt-tRNA variants.
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14
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Abstract
Mitochondria play various important roles in energy production, metabolism, and apoptosis. Mitochondrial dysfunction caused by alterations in mitochondrial DNA (mtDNA) can lead to the initiation and progression of cancers and other diseases. These alterations include mutations and copy number variations. Especially, the mutations in D-loop, MT-ND1, and MT-ND5 affect mitochondrial functions and are widely detected in various cancers. Meanwhile, several other mutations have been correlated with muscular and neuronal diseases, especially MT-TL1 is deeply related. These pieces of evidence indicated mtDNA alterations in diseases show potential as a novel therapeutic target. mtDNA repair enzymes are the target for delaying or stalling the mtDNA damage-induced cancer progression and metastasis. Moreover, some mutations reveal a prognosis ability of the drug resistance. Current efforts aim to develop mitochondrial transplantation technique as a direct cure for deregulated mitochondria-associated diseases. This review summarizes the implications of mitochondrial dysfunction in cancers and other pathologies; and discusses the relevance of mitochondria-targeted therapies, along with their contribution as potential biomarkers.
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Affiliation(s)
- Ngoc Ngo Yen Nguyen
- Department of Biomedical Science, Graduate School, Kyung Hee University, Seoul, Republic of Korea.,Biomedical Science Institute, Kyung Hee University, Seoul, Republic of Korea
| | - Sung Soo Kim
- Biomedical Science Institute, Kyung Hee University, Seoul, Republic of Korea.,Department of Biochemistry and Molecular Biology, School of Medicine, Kyung Hee University, Seoul, Republic of Korea
| | - Yong Hwa Jo
- Biomedical Science Institute, Kyung Hee University, Seoul, Republic of Korea.,Department of Biochemistry and Molecular Biology, School of Medicine, Kyung Hee University, Seoul, Republic of Korea
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15
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Toompuu M, Tuomela T, Laine P, Paulin L, Dufour E, Jacobs HT. Polyadenylation and degradation of structurally abnormal mitochondrial tRNAs in human cells. Nucleic Acids Res 2019. [PMID: 29518244 PMCID: PMC6007314 DOI: 10.1093/nar/gky159] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
RNA 3' polyadenylation is known to serve diverse purposes in biology, in particular, regulating mRNA stability and translation. Here we determined that, upon exposure to high levels of the intercalating agent ethidium bromide (EtBr), greater than those required to suppress mitochondrial transcription, mitochondrial tRNAs in human cells became polyadenylated. Relaxation of the inducing stress led to rapid turnover of the polyadenylated tRNAs. The extent, kinetics and duration of tRNA polyadenylation were EtBr dose-dependent, with mitochondrial tRNAs differentially sensitive to the stress. RNA interference and inhibitor studies indicated that ongoing mitochondrial ATP synthesis, plus the mitochondrial poly(A) polymerase and SUV3 helicase were required for tRNA polyadenylation, while polynucleotide phosphorylase counteracted the process and was needed, along with SUV3, for degradation of the polyadenylated tRNAs. Doxycycline treatment inhibited both tRNA polyadenylation and turnover, suggesting a possible involvement of the mitoribosome, although other translational inhibitors had only minor effects. The dysfunctional tRNALeu(UUR) bearing the pathological A3243G mutation was constitutively polyadenylated at a low level, but this was markedly enhanced after doxycycline treatment. We propose that polyadenylation of structurally and functionally abnormal mitochondrial tRNAs entrains their PNPase/SUV3-mediated destruction, and that this pathway could play an important role in mitochondrial diseases associated with tRNA mutations.
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Affiliation(s)
- Marina Toompuu
- Faculty of Medicine and Life Sciences, BioMediTech Institute and Tampere University Hospital, FI-33014 University of Tampere, Finland
| | - Tea Tuomela
- Faculty of Medicine and Life Sciences, BioMediTech Institute and Tampere University Hospital, FI-33014 University of Tampere, Finland
| | - Pia Laine
- Institute of Biotechnology, FI-00014 University of Helsinki, Finland
| | - Lars Paulin
- Institute of Biotechnology, FI-00014 University of Helsinki, Finland
| | - Eric Dufour
- Faculty of Medicine and Life Sciences, BioMediTech Institute and Tampere University Hospital, FI-33014 University of Tampere, Finland
| | - Howard T Jacobs
- Faculty of Medicine and Life Sciences, BioMediTech Institute and Tampere University Hospital, FI-33014 University of Tampere, Finland.,Institute of Biotechnology, FI-00014 University of Helsinki, Finland
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16
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Uittenbogaard M, Wang H, Zhang VW, Wong LJ, Brantner CA, Gropman A, Chiaramello A. The nuclear background influences the penetrance of the near-homoplasmic m.1630 A > G MELAS variant in a symptomatic proband and asymptomatic mother. Mol Genet Metab 2019; 126:429-438. [PMID: 30709774 PMCID: PMC6773428 DOI: 10.1016/j.ymgme.2019.01.022] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 01/23/2019] [Accepted: 01/24/2019] [Indexed: 01/17/2023]
Abstract
In this study, we report the metabolic consequences of the m.1630 A > G variant in fibroblasts from the symptomatic proband affected with the mitochondrial encephalomyopathy lactic acidosis and stroke-like episode Syndrome and her asymptomatic mother. By long-range PCR followed by massively parallel sequencing of the mitochondrial genome, we accurately measured heteroplasmy in fibroblasts from the proband (89.6%) and her mother (94.8%). Using complementary experimental approaches, we show a functional correlation between manifestation of clinical symptoms and bioenergetic potential. Our mitochondrial morphometric analysis reveals a link between defects of mitochondrial cristae ultrastructure and symptomatic status. Despite near-homoplasmic level of the m.1630A > G variant, the mother's fibroblasts have a normal OXPHOS metabolism, which stands in contrast to the severely impaired OXPHOS response of the proband's fibroblasts. The proband's fibroblasts also exhibit glycolysis at near constitutive levels resulting in a stunted compensatory glycolytic response to offset the severe OXPHOS defect. Whole exome sequencing reveals the presence of a heterozygous nonsense VARS2 variant (p.R334X) exclusively in the proband, which removes two thirds of the VARS2 protein containing key domains interacting with the mt-tRNAval and may play a role in modulating the penetrance of the m.1630A > G variant despite similar near homoplasmic levels. Our transmission electron microscopy study also shows unexpected ultrastructural changes of chromatin suggestive of differential epigenomic regulation between the proband and her mother that may explain the differential OXPHOS response between the proband and her mother. Future study will decipher by which molecular mechanisms the nuclear background influences the penetrance of the m.1630 A > G variant causing MELAS.
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Affiliation(s)
- Martine Uittenbogaard
- Department of Anatomy and Cell Biology, George Washington University School of Medicine and Health Sciences, Washington, DC 20037, USA
| | - Hao Wang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Victor Wei Zhang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; AmCare Genomics Laboratory, GuangZhou 510300, China
| | - Lee-Jun Wong
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Christine A Brantner
- GW Nanofabrication and Imaging Center, Office of the Vice President for Research, George Washington University, Washington, DC 20052, USA
| | - Andrea Gropman
- Children's National Medical Center, Division of Neurogenetics and Developmental Pediatrics, Washington, DC 20010, USA
| | - Anne Chiaramello
- Department of Anatomy and Cell Biology, George Washington University School of Medicine and Health Sciences, Washington, DC 20037, USA.
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17
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Kim MY, Cho S, Lee JH, Seo HJ, Lee SD. Detection of Innate and Artificial Mitochondrial DNA Heteroplasmy by Massively Parallel Sequencing: Considerations for Analysis. J Korean Med Sci 2018; 33:e337. [PMID: 30584415 PMCID: PMC6300661 DOI: 10.3346/jkms.2018.33.e337] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Accepted: 10/02/2018] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Mitochondrial heteroplasmy, the co-existence of different mitochondrial polymorphisms within an individual, has various forensic and clinical implications. But there is still no guideline on the application of massively parallel sequencing (MPS) in heteroplasmy detection. We present here some critical issues that should be considered in heteroplasmy studies using MPS. METHODS Among five samples with known innate heteroplasmies, two pairs of mixture were generated for artificial heteroplasmies with target minor allele frequencies (MAFs) ranging from 50% to 1%. Each sample was amplified by two-amplicon method and sequenced by Ion Torrent system. The outcomes of two different analysis tools, Torrent Suite Variant Caller (TVC) and mtDNA-Server (mDS), were compared. RESULTS All the innate heteroplasmies were detected correctly by both analysis tools. Average MAFs of artificial heteroplasmies correlated well to the target values. The detection rates were almost 90% for high-level heteroplasmies, but decreased for low-level heteroplasmies. TVC generally showed lower detection rates than mDS, which seems to be due to their own computation algorithms which drop out some reference-dominant heteroplasmies. Meanwhile, mDS reported several unintended low-level heteroplasmies which were suggested as nuclear mitochondrial DNA sequences. The average coverage depth of each sample placed on the same chip showed considerable variation. The increase of coverage depth had no effect on the detection rates. CONCLUSION In addition to the general accuracy of the MPS application on detecting heteroplasmy, our study indicates that the understanding of the nature of mitochondrial DNA and analysis algorithm would be crucial for appropriate interpretation of MPS results.
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Affiliation(s)
- Moon-Young Kim
- Department of Forensic Medicine, Seoul National University College of Medicine, Seoul, Korea
| | - Sohee Cho
- Institute of Forensic Science, Seoul National University College of Medicine, Seoul, Korea
| | - Ji Hyun Lee
- Department of Forensic Medicine, Seoul National University College of Medicine, Seoul, Korea
| | - Hee Jin Seo
- Department of Forensic Medicine, Seoul National University College of Medicine, Seoul, Korea
| | - Soong Deok Lee
- Department of Forensic Medicine, Seoul National University College of Medicine, Seoul, Korea
- Institute of Forensic Science, Seoul National University College of Medicine, Seoul, Korea
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18
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De Fanti S, Vicario S, Lang M, Simone D, Magli C, Luiselli D, Gianaroli L, Romeo G. Intra-individual purifying selection on mitochondrial DNA variants during human oogenesis. Hum Reprod 2017; 32:1100-1107. [PMID: 28333293 DOI: 10.1093/humrep/dex051] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 02/27/2017] [Indexed: 11/13/2022] Open
Abstract
STUDY QUESTION Does selection for mtDNA mutations occur in human oocytes? SUMMARY ANSWER We provide statistical evidence in favor of the existence of purifying selection for mtDNA mutations in human oocytes acting between the expulsion of the first and second polar bodies (PBs). WHAT IS KNOWN ALREADY Several lines of evidence in Metazoa, including humans, indicate that variation within the germline of mitochondrial genomes is under purifying selection. The presence of this internal selection filter in the germline has important consequences for the evolutionary trajectory of mtDNA. However, the nature and localization of this internal filter are still unclear while several hypotheses are proposed in the literature. STUDY DESIGN, SIZE, DURATION In this study, 60 mitochondrial genomes were sequenced from 17 sets of oocytes, first and second PBs, and peripheral blood taken from nine women between 38 and 43 years of age. PARTICIPANTS/MATERIALS, SETTING, METHODS Whole genome amplification was performed only on the single cell samples and Sanger sequencing was performed on amplicons. The comparison of variant profiles between first and second PB sequences showed no difference in substitution rates but displayed instead a sharp difference in pathogenicity scores of protein-coding sequences using three different metrics (MutPred, Polyphen and SNPs&GO). MAIN RESULTS AND THE ROLE OF CHANCE Unlike the first, second PBs showed no significant differences in pathogenic scores with blood and oocyte sequences. This suggests that a filtering mechanism for disadvantageous variants operates during oocyte development between the expulsion of the first and second PB. LARGE SCALE DATA N/A. LIMITATIONS, REASONS FOR CAUTION The sample size is small and further studies are needed before this approach can be used in clinical practice. Studies on a model organism would allow the sample size to be increased. WIDER IMPLICATIONS OF THE FINDINGS This work opens the way to the study of the correlation between mtDNA mutations, mitochondrial capacity and viability of oocytes. STUDY FUNDING/COMPETING INTEREST(S) This work was supported by a SISMER grant. Laboratory facilities and skills were freely provided by SISMER, and by the Alma Mater Studiorum, University of Bologna. The authors have no conflict of interest to disclose.
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Affiliation(s)
- Sara De Fanti
- Department of Biological, Geological and Environmental Sciences, University of Bologna, Bologna 40126, Italy
| | - Saverio Vicario
- Institute of Atmospheric Pollution Research, National Research Council, C/O Physics Department, University of Bari 'Aldo Moro', Bari 70132, Italy
| | - Martin Lang
- Medical Genetics Unit, S. Orsola Hospital, University of Bologna, Bologna 40126, Italy.,Current address: Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Domenico Simone
- Department of Bioscience, Biotechnology and Biopharmaceutics, University of Bari 'Aldo Moro',Bari70132, Italy
| | - Cristina Magli
- Reproductive Medicine Unit, S.I.S.Me.R., Bologna 40138, Italy
| | - Donata Luiselli
- Department of Biological, Geological and Environmental Sciences, University of Bologna, Bologna 40126, Italy
| | - Luca Gianaroli
- Reproductive Medicine Unit, S.I.S.Me.R., Bologna 40138, Italy
| | - Giovanni Romeo
- Medical Genetics Unit, S. Orsola Hospital, University of Bologna, Bologna 40126, Italy
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19
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Chrzanowska-Lightowlers Z, Rorbach J, Minczuk M. Human mitochondrial ribosomes can switch structural tRNAs - but when and why? RNA Biol 2017; 14:1668-1671. [PMID: 28786741 PMCID: PMC5731804 DOI: 10.1080/15476286.2017.1356551] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
High resolution cryoEM of mammalian mitoribosomes revealed the unexpected presence of mitochondrially encoded tRNA as a structural component of mitochondrial large ribosomal subunit (mt-LSU). Our previously published data identified that only mitochondrial (mt-) tRNAPhe and mt-tRNAVal can be incorporated into mammalian mt-LSU and within an organism there is no evidence of tissue specific variation. When mt-tRNAVal is limiting, human mitoribosomes can integrate mt-tRNAPhe instead to generate a translationally competent monosome. Here we discuss the possible reasons for and consequences of the observed plasticity of the structural mt-tRNA integration. We also indicate potential direction for further research that could help our understanding of the mechanistic and evolutionary aspects of this unprecedented system.
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Affiliation(s)
- Zofia Chrzanowska-Lightowlers
- a The Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience , Newcastle University , Newcastle upon Tyne , England , UK
| | - Joanna Rorbach
- b Department of Medical Biochemistry and Biophysics , Karolinska Institutet , Retzius väg 8, Stockholm , Sweden
| | - Michal Minczuk
- c MRC Mitochondrial Biology Unit , Wellcome Trust/MRC Building, Hills Road, Cambridge, England , UK
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20
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Abstract
Mitochondria are intracellular organelles responsible for adenosine triphosphate production. The strict control of intracellular energy needs require proper mitochondrial functioning. The mitochondria are under dual controls of mitochondrial DNA (mtDNA) and nuclear DNA (nDNA). Mitochondrial dysfunction can arise from changes in either mtDNA or nDNA genes regulating function. There are an estimated ∼1500 proteins in the mitoproteome, whereas the mtDNA genome has 37 proteins. There are, to date, ∼275 genes shown to give rise to disease. The unique physiology of mitochondrial functioning contributes to diverse gene expression. The onset and range of phenotypic expression of disease is diverse, with onset from neonatal to seventh decade of life. The range of dysfunction is heterogeneous, ranging from single organ to multisystem involvement. The complexity of disease expression has severely limited gene discovery. Combining phenotypes with improvements in gene sequencing strategies are improving the diagnosis process. This chapter focuses on the interplay of the unique physiology and gene discovery in the current knowledge of genetically derived mitochondrial disease.
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Affiliation(s)
- Russell P Saneto
- Seattle Children's Hospital/University of Washington, Seattle, WA, United States.
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21
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Morrow EH, Camus MF. Mitonuclear epistasis and mitochondrial disease. Mitochondrion 2017; 35:119-122. [PMID: 28603048 DOI: 10.1016/j.mito.2017.06.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 06/06/2017] [Accepted: 06/06/2017] [Indexed: 12/01/2022]
Affiliation(s)
- Edward H Morrow
- School of Life Sciences, University of Sussex, Brighton BN1 9QG, United Kingdom.
| | - M Florencia Camus
- Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, United Kingdom
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22
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Scarpelli M, Todeschini A, Volonghi I, Padovani A, Filosto M. Mitochondrial diseases: advances and issues. APPLICATION OF CLINICAL GENETICS 2017; 10:21-26. [PMID: 28243136 PMCID: PMC5317313 DOI: 10.2147/tacg.s94267] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Mitochondrial diseases (MDs) are a clinically heterogeneous group of disorders caused by a dysfunction of the mitochondrial respiratory chain. They can be related to mutation of genes encoded using either nuclear DNA or mitochondrial DNA. The advent of next generation sequencing and whole exome sequencing in studying the molecular bases of MDs will bring about a revolution in the field of mitochondrial medicine, also opening the possibility of better defining pathogenic mechanisms and developing novel therapeutic approaches for these devastating disorders. The canonical rules of mitochondrial medicine remain milestones, but novel issues have been raised following the use of advanced diagnostic technologies. Rigorous validation of the novel mutations detected using deep sequencing in patients with suspected MD, and a clear definition of the natural history, outcome measures, and biomarkers that could be usefully adopted in clinical trials, are mandatory goals for the scientific community. Today, therapy is often inadequate and mostly palliative. However, important advances have been made in treating some clinical entities, eg, mitochondrial neuro-gastrointestinal encephalomyopathy, for which approaches using allogeneic hematopoietic stem cell transplantation, orthotopic liver transplantation, and carrier erythrocyte entrapped thymidine phosphorylase enzyme therapy have recently been developed. Promising new treatment methods are being identified so that researchers, clinicians, and patients can join forces to change the history of these untreatable disorders.
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Affiliation(s)
- Mauro Scarpelli
- Department of Neuroscience, Unit of Neurology, Azienda Ospedaliera Universitaria Integrata Verona, Verona, Italy
| | - Alice Todeschini
- Center for Neuromuscular Diseases and Neuropathies, Unit of Neurology, ASST "Spedali Civili", University of Brescia, Brescia, Italy
| | - Irene Volonghi
- Center for Neuromuscular Diseases and Neuropathies, Unit of Neurology, ASST "Spedali Civili", University of Brescia, Brescia, Italy
| | - Alessandro Padovani
- Center for Neuromuscular Diseases and Neuropathies, Unit of Neurology, ASST "Spedali Civili", University of Brescia, Brescia, Italy
| | - Massimiliano Filosto
- Center for Neuromuscular Diseases and Neuropathies, Unit of Neurology, ASST "Spedali Civili", University of Brescia, Brescia, Italy
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23
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Pereira CV, Moraes CT. Current strategies towards therapeutic manipulation of mtDNA heteroplasmy. Front Biosci (Landmark Ed) 2017; 22:991-1010. [PMID: 27814659 DOI: 10.2741/4529] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Mitochondrial disease is a multifactorial disorder involving both nuclear and mitochondrial genomes. Over the past 20 years, great progress was achieved in the field of gene editing which raised the possibility of partial or complete elimination of mutant mtDNA that causes disease phenotypes. Each cell contains thousands of copies of mtDNA which can be either wild-type (WT) or mutant, a condition called heteroplasmy. As there are multiple copies of mtDNA inside a cell, the percentage of mutant mtDNA can vary and a directional shift in the heteroplasmy ratio towards an increase of WT mtDNA copies would have therapeutic value. Gene editing tools have been adapted to translocate to mitochondria and were able to change heteroplasmy in a predictable manner. These include mitochondrial targeted restriction endonucleases, Zinc-finger nucleases, and TAL-effector nucleases. These procedures could also be adapted to reduce the levels of mutant mtDNA in embryos, offering an option to the controversial mitochondrial replacement techniques during in vitro fertilization. The current strategies to induce heteroplasmy shift of mtDNA and its implications will be comprehensively discussed.
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Affiliation(s)
- Claudia V Pereira
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Carlos T Moraes
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL 33136, USA,
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24
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Ng YS, Feeney C, Schaefer AM, Holmes CE, Hynd P, Alston CL, Grady JP, Roberts M, Maguire M, Bright A, Taylor RW, Yiannakou Y, McFarland R, Turnbull DM, Gorman GS. Pseudo-obstruction, stroke, and mitochondrial dysfunction: A lethal combination. Ann Neurol 2016; 80:686-692. [PMID: 27453452 PMCID: PMC5215534 DOI: 10.1002/ana.24736] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 06/28/2016] [Accepted: 07/14/2016] [Indexed: 12/28/2022]
Abstract
OBJECTIVES The m.3243A>G MTTL1 mutation is the most common cause of mitochondrial disease; yet there is limited awareness of intestinal pseudo-obstruction (IPO) in this disorder. We aimed to determine the prevalence, severity, and clinical outcome of patients with m.3243A>G-related mitochondrial disease manifesting with IPO. METHODS In this large, observational cohort study, we assessed the clinical, molecular, and radiological characteristics of patients with genetically determined m.3243A>G-related mitochondrial disease, who presented with severe symptoms suggestive of bowel obstruction in the absence of an occluding lesion. RESULTS Between January 2009 and June 2015, 226 patients harbouring the m.3243A>G mutation were recruited to the Medical Research Council Centre Mitochondrial Disease Patient Cohort, Newcastle. Thirty patients (13%) presented acutely with IPO. Thirteen of these patients had a preceding history of stroke-like episodes, whereas 1 presented 27 years previously with their first stroke-like episode. Eight patients developed IPO concomitantly during an acute stroke-like episode. Regression analysis suggested stroke was the strongest predictor for development of IPO, in addition to cardiomyopathy, low body mass index and high urinary mutation load. Poor clinical outcome was observed in 6 patients who underwent surgical procedures. INTERPRETATION Our findings suggest, in this common mitochondrial disease, that IPO is an under-recognized, often misdiagnosed clinical entity. Poor clinical outcome associated with stroke and acute surgical intervention highlights the importance of the neurologist having a high index of suspicion, particularly in the acute setting, to instigate timely coordination of appropriate care and management with other specialists. Ann Neurol 2016;80:686-692.
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Affiliation(s)
- Yi Shiau Ng
- Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Catherine Feeney
- Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Andrew M Schaefer
- Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Carol Ellen Holmes
- Department of Radiology, The Newcastle upon Tyne Hospitals NHS Foundation Trust, Royal Victoria Infirmary, Newcastle upon Tyne, United Kingdom
| | - Paula Hynd
- Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Charlotte L Alston
- Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - John P Grady
- Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Mark Roberts
- The Greater Manchester Neuroscience Centre, Salford Royal NHS Foundation Trust, Salford, United Kingdom
| | - Mellisa Maguire
- Department of Neurology, The Leeds Teaching Hospitals NHS Trust, West Yorkshire, United Kingdom
| | - Alexandra Bright
- Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Robert W Taylor
- Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Yan Yiannakou
- Department of Gastroenterology, County Durham and Darlington NHS Foundation Trust, Durham, United Kingdom
| | - Robert McFarland
- Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Doug M Turnbull
- Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Gráinne S Gorman
- Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom
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25
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López-Gallardo E, Llobet L, Emperador S, Montoya J, Ruiz-Pesini E. Effects of Tributyltin Chloride on Cybrids with or without an ATP Synthase Pathologic Mutation. ENVIRONMENTAL HEALTH PERSPECTIVES 2016; 124:1399-405. [PMID: 27129022 PMCID: PMC5010394 DOI: 10.1289/ehp182] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Revised: 11/27/2015] [Accepted: 04/13/2016] [Indexed: 05/05/2023]
Abstract
BACKGROUND The oxidative phosphorylation system (OXPHOS) includes nuclear chromosome (nDNA)- and mitochondrial DNA (mtDNA)-encoded polypeptides. Many rare OXPHOS disorders, such as striatal necrosis syndromes, are caused by genetic mutations. Despite important advances in sequencing procedures, causative mutations remain undetected in some patients. It is possible that etiologic factors, such as environmental toxins, are the cause of these cases. Indeed, the inhibition of a particular enzyme by a poison could imitate the biochemical effects of pathological mutations in that enzyme. Moreover, environmental factors can modify the penetrance or expressivity of pathological mutations. OBJECTIVES We studied the interaction between mitochondrially encoded ATP synthase 6 (p.MT-ATP6) subunit and an environmental exposure that may contribute phenotypic differences between healthy individuals and patients suffering from striatal necrosis syndromes or other mitochondriopathies. METHODS We analyzed the effects of the ATP synthase inhibitor tributyltin chloride (TBTC), a widely distributed environmental factor that contaminates human food and water, on transmitochondrial cell lines with or without an ATP synthase mutation that causes striatal necrosis syndrome. Doses were selected based on TBTC concentrations previously reported in human whole blood samples. RESULTS TBTC modified the phenotypic effects caused by a pathological mtDNA mutation. Interestingly, wild-type cells treated with this xenobiotic showed similar bioenergetics when compared with the untreated mutated cells. CONCLUSIONS In addition to the known genetic causes, our findings suggest that environmental exposure to TBTC might contribute to the etiology of striatal necrosis syndromes. CITATION López-Gallardo E, Llobet L, Emperador S, Montoya J, Ruiz-Pesini E. 2016. Effects of tributyltin chloride on cybrids with or without an ATP synthase pathologic mutation. Environ Health Perspect 124:1399-1405; http://dx.doi.org/10.1289/EHP182.
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Affiliation(s)
- Ester López-Gallardo
- Departamento de Bioquímica, Biología Molecular y Celular,
- Instituto de Investigación Sanitaria de Aragón,
- CIBER de Enfermedades Raras (CIBERER), and
| | - Laura Llobet
- Departamento de Bioquímica, Biología Molecular y Celular,
- Instituto de Investigación Sanitaria de Aragón,
- CIBER de Enfermedades Raras (CIBERER), and
| | - Sonia Emperador
- Departamento de Bioquímica, Biología Molecular y Celular,
- Instituto de Investigación Sanitaria de Aragón,
- CIBER de Enfermedades Raras (CIBERER), and
| | - Julio Montoya
- Departamento de Bioquímica, Biología Molecular y Celular,
- Instituto de Investigación Sanitaria de Aragón,
- CIBER de Enfermedades Raras (CIBERER), and
- Address correspondence to E. Ruiz-Pesini, Departamento de Bioquímica, Biología Molecular y Celular, Universidad de Zaragoza. C/ Miguel Servet, 177. 50013-Zaragoza, Spain. Telephone: 34-976761640. E-mail: , or J. Montoya, Departamento de Bioquímica, Biología Molecular y Celular, Universidad de Zaragoza. C/ Miguel Servet, 177. 50013-Zaragoza, Spain. Telephone: 34-976761640. E-mail:
| | - Eduardo Ruiz-Pesini
- Departamento de Bioquímica, Biología Molecular y Celular,
- Instituto de Investigación Sanitaria de Aragón,
- CIBER de Enfermedades Raras (CIBERER), and
- Fundación ARAID, Universidad de Zaragoza, Zaragoza, Spain
- Address correspondence to E. Ruiz-Pesini, Departamento de Bioquímica, Biología Molecular y Celular, Universidad de Zaragoza. C/ Miguel Servet, 177. 50013-Zaragoza, Spain. Telephone: 34-976761640. E-mail: , or J. Montoya, Departamento de Bioquímica, Biología Molecular y Celular, Universidad de Zaragoza. C/ Miguel Servet, 177. 50013-Zaragoza, Spain. Telephone: 34-976761640. E-mail:
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Abstract
Ten years ago, there was an emerging view that the molecular basis for adult mitochondrial disorders was largely known and that the clinical phenotypes had been well described. Nothing could have been further from the truth. The establishment of large cohorts of patients has revealed new aspects of the clinical presentation that were not previously appreciated. Over time, this approach is starting to provide an accurate understanding of the natural history of mitochondrial disease in adults. Advances in molecular diagnostics, underpinned by next generation sequencing technology, have identified novel molecular mechanisms. Recently described mitochondrial disease phenotypes have disparate causes, and yet share common mechanistic themes. In particular, disorders of mtDNA maintenance have emerged as a major cause of mitochondrial disease in adults. Progressive mtDNA depletion and the accumulation of mtDNA mutations explain some of the clinical features, but the genetic and cellular processes responsible for the mtDNA abnormalities are not entirely clear in each instance. Unfortunately, apart from a few specific examples, treatments for adult mitochondrial disease have not been forthcoming. However, the establishment of international consortia, and the first multinational randomised controlled trial, have paved the way for major progress in the near future, underpinned by growing interest from the pharmaceutical industry. Adult mitochondrial medicine is, therefore, in its infancy, and the challenge is to harness the new understanding of its molecular and cellular basis to develop treatments of real benefit to patients.
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Affiliation(s)
- Patrick F Chinnery
- Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge, UK Medical Research Council - Mitochondrial Biology Unit, Cambridge Biomedical Campus, Cambridge, UK
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Hyslop LA, Blakeley P, Craven L, Richardson J, Fogarty NME, Fragouli E, Lamb M, Wamaitha SE, Prathalingam N, Zhang Q, O'Keefe H, Takeda Y, Arizzi L, Alfarawati S, Tuppen HA, Irving L, Kalleas D, Choudhary M, Wells D, Murdoch AP, Turnbull DM, Niakan KK, Herbert M. Towards clinical application of pronuclear transfer to prevent mitochondrial DNA disease. Nature 2016; 534:383-6. [PMID: 27281217 PMCID: PMC5131843 DOI: 10.1038/nature18303] [Citation(s) in RCA: 199] [Impact Index Per Article: 24.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 05/03/2016] [Indexed: 12/11/2022]
Abstract
Mitochondrial DNA (mtDNA) mutations are maternally inherited and are associated with a broad range of debilitating and fatal diseases. Reproductive technologies designed to uncouple the inheritance of mtDNA from nuclear DNA may enable affected women to have a genetically related child with a greatly reduced risk of mtDNA disease. Here we report the first preclinical studies on pronuclear transplantation (PNT). Surprisingly, techniques used in proof-of-concept studies involving abnormally fertilized human zygotes were not well tolerated by normally fertilized zygotes. We have therefore developed an alternative approach based on transplanting pronuclei shortly after completion of meiosis rather than shortly before the first mitotic division. This promotes efficient development to the blastocyst stage with no detectable effect on aneuploidy or gene expression. After optimization, mtDNA carryover was reduced to <2% in the majority (79%) of PNT blastocysts. The importance of reducing carryover to the lowest possible levels is highlighted by a progressive increase in heteroplasmy in a stem cell line derived from a PNT blastocyst with 4% mtDNA carryover. We conclude that PNT has the potential to reduce the risk of mtDNA disease, but it may not guarantee prevention.
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Affiliation(s)
- Louise A Hyslop
- Wellcome Trust Centre for Mitochondrial Research, Institute of Genetic Medicine, Biomedicine West Wing, Centre for Life, Times Square, Newcastle upon Tyne NE1 3BZ, UK
- Newcastle Fertility Centre, Biomedicine West Wing, Centre for Life, Times Square, Newcastle upon Tyne NE1 4EP, UK
| | - Paul Blakeley
- The Francis Crick Institute, Human Embryo and Stem Cell Laboratory, Mill Hill Laboratory, Mill Hill, London NW7 1AA, UK
| | - Lyndsey Craven
- Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, The Medical School, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
| | - Jessica Richardson
- Wellcome Trust Centre for Mitochondrial Research, Institute of Genetic Medicine, Biomedicine West Wing, Centre for Life, Times Square, Newcastle upon Tyne NE1 3BZ, UK
| | - Norah M E Fogarty
- The Francis Crick Institute, Human Embryo and Stem Cell Laboratory, Mill Hill Laboratory, Mill Hill, London NW7 1AA, UK
| | - Elpida Fragouli
- Reprogenetics UK, Institute of Reproductive Sciences, Oxford Business Park North, Oxford OX4 2HW, UK
| | - Mahdi Lamb
- Wellcome Trust Centre for Mitochondrial Research, Institute of Genetic Medicine, Biomedicine West Wing, Centre for Life, Times Square, Newcastle upon Tyne NE1 3BZ, UK
| | - Sissy E Wamaitha
- The Francis Crick Institute, Human Embryo and Stem Cell Laboratory, Mill Hill Laboratory, Mill Hill, London NW7 1AA, UK
| | - Nilendran Prathalingam
- Wellcome Trust Centre for Mitochondrial Research, Institute of Genetic Medicine, Biomedicine West Wing, Centre for Life, Times Square, Newcastle upon Tyne NE1 3BZ, UK
- Newcastle Fertility Centre, Biomedicine West Wing, Centre for Life, Times Square, Newcastle upon Tyne NE1 4EP, UK
| | - Qi Zhang
- Wellcome Trust Centre for Mitochondrial Research, Institute of Genetic Medicine, Biomedicine West Wing, Centre for Life, Times Square, Newcastle upon Tyne NE1 3BZ, UK
| | - Hannah O'Keefe
- Wellcome Trust Centre for Mitochondrial Research, Institute of Genetic Medicine, Biomedicine West Wing, Centre for Life, Times Square, Newcastle upon Tyne NE1 3BZ, UK
| | - Yuko Takeda
- Wellcome Trust Centre for Mitochondrial Research, Institute of Genetic Medicine, Biomedicine West Wing, Centre for Life, Times Square, Newcastle upon Tyne NE1 3BZ, UK
| | - Lucia Arizzi
- Wellcome Trust Centre for Mitochondrial Research, Institute of Genetic Medicine, Biomedicine West Wing, Centre for Life, Times Square, Newcastle upon Tyne NE1 3BZ, UK
- Newcastle Fertility Centre, Biomedicine West Wing, Centre for Life, Times Square, Newcastle upon Tyne NE1 4EP, UK
| | - Samer Alfarawati
- Reprogenetics UK, Institute of Reproductive Sciences, Oxford Business Park North, Oxford OX4 2HW, UK
| | - Helen A Tuppen
- Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, The Medical School, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
| | - Laura Irving
- Wellcome Trust Centre for Mitochondrial Research, Institute of Genetic Medicine, Biomedicine West Wing, Centre for Life, Times Square, Newcastle upon Tyne NE1 3BZ, UK
| | - Dimitrios Kalleas
- Wellcome Trust Centre for Mitochondrial Research, Institute of Genetic Medicine, Biomedicine West Wing, Centre for Life, Times Square, Newcastle upon Tyne NE1 3BZ, UK
| | - Meenakshi Choudhary
- Newcastle Fertility Centre, Biomedicine West Wing, Centre for Life, Times Square, Newcastle upon Tyne NE1 4EP, UK
| | - Dagan Wells
- University of Oxford, Nuffield Department of Obstetrics and Gynaecology, John Radcliffe Hospital, Oxford OX3 9DU, UK
| | - Alison P Murdoch
- Newcastle Fertility Centre, Biomedicine West Wing, Centre for Life, Times Square, Newcastle upon Tyne NE1 4EP, UK
| | - Douglass M Turnbull
- Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, The Medical School, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
| | - Kathy K Niakan
- The Francis Crick Institute, Human Embryo and Stem Cell Laboratory, Mill Hill Laboratory, Mill Hill, London NW7 1AA, UK
| | - Mary Herbert
- Wellcome Trust Centre for Mitochondrial Research, Institute of Genetic Medicine, Biomedicine West Wing, Centre for Life, Times Square, Newcastle upon Tyne NE1 3BZ, UK
- Newcastle Fertility Centre, Biomedicine West Wing, Centre for Life, Times Square, Newcastle upon Tyne NE1 4EP, UK
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Khan NA, Govindaraj P, Meena AK, Thangaraj K. Mitochondrial disorders: challenges in diagnosis & treatment. Indian J Med Res 2016; 141:13-26. [PMID: 25857492 PMCID: PMC4405934 DOI: 10.4103/0971-5916.154489] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Mitochondrial dysfunctions are known to be responsible for a number of heterogenous clinical presentations with multi-systemic involvement. Impaired oxidative phosphorylation leading to a decrease in cellular energy (ATP) production is the most important cause underlying these disorders. Despite significant progress made in the field of mitochondrial medicine during the last two decades, the molecular mechanisms underlying these disorders are not fully understood. Since the identification of first mitochondrial DNA (mtDNA) mutation in 1988, there has been an exponential rise in the identification of mtDNA and nuclear DNA mutations that are responsible for mitochondrial dysfunction and disease. Genetic complexity together with ever widening clinical spectrum associated with mitochondrial dysfunction poses a major challenge in diagnosis and treatment. Effective therapy has remained elusive till date and is mostly efficient in relieving symptoms. In this review, we discuss the important clinical and genetic features of mitochondrials disorders with special emphasis on diagnosis and treatment.
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Affiliation(s)
| | | | | | - Kumarasamy Thangaraj
- CSIR-Centre for Cellular & Molecular Biology, Nizam's Institute of Medical Sciences, Hyderabad, India
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29
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Ardissone A, Invernizzi F, Nasca A, Moroni I, Farina L, Ghezzi D. Mitochondrial leukoencephalopathy and complex II deficiency associated with a recessive SDHB mutation with reduced penetrance. Mol Genet Metab Rep 2015; 5:51-54. [PMID: 26925370 PMCID: PMC4695914 DOI: 10.1016/j.ymgmr.2015.10.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Revised: 10/13/2015] [Accepted: 10/13/2015] [Indexed: 11/04/2022] Open
Affiliation(s)
- Anna Ardissone
- Unit of Child Neurology, Fondazione Istituto Neurologico 'Carlo Besta', IRCCS, Milan, Italy
| | - Federica Invernizzi
- Unit of Molecular Neurogenetics, Fondazione Istituto Neurologico 'Carlo Besta', IRCCS, Milan, Italy
| | - Alessia Nasca
- Unit of Molecular Neurogenetics, Fondazione Istituto Neurologico 'Carlo Besta', IRCCS, Milan, Italy
| | - Isabella Moroni
- Unit of Child Neurology, Fondazione Istituto Neurologico 'Carlo Besta', IRCCS, Milan, Italy
| | - Laura Farina
- Unit of Neuroradiology, Fondazione Istituto Neurologico 'Carlo Besta', IRCCS, Milan, Italy
| | - Daniele Ghezzi
- Unit of Child Neurology, Fondazione Istituto Neurologico 'Carlo Besta', IRCCS, Milan, Italy
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30
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Appleby JB. The ethical challenges of the clinical introduction of mitochondrial replacement techniques. MEDICINE, HEALTH CARE, AND PHILOSOPHY 2015; 18:501-14. [PMID: 26239841 PMCID: PMC4591199 DOI: 10.1007/s11019-015-9656-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Mitochondrial DNA (mtDNA) diseases are a group of neuromuscular diseases that often cause suffering and premature death. New mitochondrial replacement techniques (MRTs) may offer women with mtDNA diseases the opportunity to have healthy offspring to whom they are genetically related. MRTs will likely be ready to license for clinical use in the near future and a discussion of the ethics of the clinical introduction of MRTs is needed. This paper begins by evaluating three concerns about the safety of MRTs for clinical use on humans: (1) Is it ethical to use MRTs if safe alternatives exist? (2) Would persons with three genetic contributors be at risk of suffering? and (3) Can society trust that MRTs will be made available for humans only once adequate safety testing has taken place, and that MRTs will only be licensed for clinical use in a way that minimises risks? It is then argued that the ethics debate about MRTs should be reoriented towards recommending ways to reduce the possible risks of MRT use on humans. Two recommendations are made: (1) licensed clinical access to MRTs should only be granted to prospective parents if they intend to tell their children about their MRT conception by adulthood; and (2) sex selection should be used in conjunction with the clinical use of MRTs, in order to reduce transgenerational health risks.
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Affiliation(s)
- John B Appleby
- Centre of Medical Law and Ethics in the Dickson Poon School of Law, King's College London, London, UK.
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31
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Stewart JB, Chinnery PF. The dynamics of mitochondrial DNA heteroplasmy: implications for human health and disease. Nat Rev Genet 2015; 16:530-42. [PMID: 26281784 DOI: 10.1038/nrg3966] [Citation(s) in RCA: 534] [Impact Index Per Article: 59.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Common genetic variants of mitochondrial DNA (mtDNA) increase the risk of developing several of the major health issues facing the western world, including neurodegenerative diseases. In this Review, we consider how these mtDNA variants arose and how they spread from their origin on one single molecule in a single cell to be present at high levels throughout a specific organ and, ultimately, to contribute to the population risk of common age-related disorders. mtDNA persists in all aerobic eukaryotes, despite a high substitution rate, clonal propagation and little evidence of recombination. Recent studies have found that de novo mtDNA mutations are suppressed in the female germ line; despite this, mtDNA heteroplasmy is remarkably common. The demonstration of a mammalian mtDNA genetic bottleneck explains how new germline variants can increase to high levels within a generation, and the ultimate fixation of less-severe mutations that escape germline selection explains how they can contribute to the risk of late-onset disorders.
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Affiliation(s)
- James B Stewart
- Max Planck Institute for Biology of Ageing, Cologne 50931, Germany
| | - Patrick F Chinnery
- Wellcome Trust Centre for Mitochondrial Research, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne NE1 1BZ, UK
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32
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De Silva D, Tu YT, Amunts A, Fontanesi F, Barrientos A. Mitochondrial ribosome assembly in health and disease. Cell Cycle 2015; 14:2226-50. [PMID: 26030272 DOI: 10.1080/15384101.2015.1053672] [Citation(s) in RCA: 130] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The ribosome is a structurally and functionally conserved macromolecular machine universally responsible for catalyzing protein synthesis. Within eukaryotic cells, mitochondria contain their own ribosomes (mitoribosomes), which synthesize a handful of proteins, all essential for the biogenesis of the oxidative phosphorylation system. High-resolution cryo-EM structures of the yeast, porcine and human mitoribosomal subunits and of the entire human mitoribosome have uncovered a wealth of new information to illustrate their evolutionary divergence from their bacterial ancestors and their adaptation to synthesis of highly hydrophobic membrane proteins. With such structural data becoming available, one of the most important remaining questions is that of the mitoribosome assembly pathway and factors involved. The regulation of mitoribosome biogenesis is paramount to mitochondrial respiration, and thus to cell viability, growth and differentiation. Moreover, mutations affecting the rRNA and protein components produce severe human mitochondrial disorders. Despite its biological and biomedical significance, knowledge on mitoribosome biogenesis and its deviations from the much-studied bacterial ribosome assembly processes is scarce, especially the order of rRNA processing and assembly events and the regulatory factors required to achieve fully functional particles. This article focuses on summarizing the current available information on mitoribosome assembly pathway, factors that form the mitoribosome assembly machinery, and the effect of defective mitoribosome assembly on human health.
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Affiliation(s)
- Dasmanthie De Silva
- a Department of Biochemistry and Molecular Biology ; University of Miami Miller School of Medicine ; Miami , FL USA
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33
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Hagen CM, Aidt FH, Havndrup O, Hedley PL, Jensen MK, Kanters JK, Pham TT, Bundgaard H, Christiansen M. Private mitochondrial DNA variants in danish patients with hypertrophic cardiomyopathy. PLoS One 2015; 10:e0124540. [PMID: 25923817 PMCID: PMC4414448 DOI: 10.1371/journal.pone.0124540] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 02/19/2015] [Indexed: 02/02/2023] Open
Abstract
Hypertrophic cardiomyopathy (HCM) is a genetic cardiac disease primarily caused by mutations in genes coding for sarcomeric proteins. A molecular-genetic etiology can be established in ~60% of cases. Evolutionarily conserved mitochondrial DNA (mtDNA) haplogroups are susceptibility factors for HCM. Several polymorphic mtDNA variants are associated with a variety of late-onset degenerative diseases and affect mitochondrial function. We examined the role of private, non-haplogroup associated, mitochondrial variants in the etiology of HCM. In 87 Danish HCM patients, full mtDNA sequencing revealed 446 variants. After elimination of 312 (69.9%) non-coding and synonymous variants, a further 109 (24.4%) with a global prevalence > 0.1%, three (0.7%) haplogroup associated and 19 (2.0%) variants with a low predicted in silico likelihood of pathogenicity, three variants: MT-TC: m.5772G>A, MT-TF: m.644A>G, and MT-CYB: m.15024G>A, p.C93Y remained. A detailed analysis of these variants indicated that none of them are likely to cause HCM. In conclusion, private mtDNA mutations are frequent, but they are rarely, if ever, associated with HCM.
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Affiliation(s)
- Christian M. Hagen
- Department of Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Frederik H. Aidt
- Department of Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark
| | - Ole Havndrup
- Department of Cardiology, Roskilde Hospital, Roskilde, Denmark
| | - Paula L. Hedley
- Department of Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark
| | - Morten K. Jensen
- Department of Medicine B, The Heart Center, Rigshospitalet, Copenhagen, Denmark
| | - Jørgen K. Kanters
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Tam T. Pham
- Department of Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark
| | - Henning Bundgaard
- Department of Medicine B, The Heart Center, Rigshospitalet, Copenhagen, Denmark
| | - Michael Christiansen
- Department of Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
- * E-mail:
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Ma J, Purcell H, Showalter L, Aagaard KM. Mitochondrial DNA sequence variation is largely conserved at birth with rare de novo mutations in neonates. Am J Obstet Gynecol 2015; 212:530.e1-8. [PMID: 25687567 DOI: 10.1016/j.ajog.2015.02.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Revised: 01/29/2015] [Accepted: 02/09/2015] [Indexed: 12/21/2022]
Abstract
OBJECTIVE Mitochondrial DNA (mtDNA) encodes the proteins of the electron transfer chain to produce adenosine triphosphate through oxidative phosphorylation, and is essential to sustain life. mtDNA is unique from the nuclear genome in so much as it is solely maternally inherited (non-mendelian patterning), and shows a relatively high rate of mutation due to the absence of error checking capacity. While it is generally assumed that most new mutations accumulate through the process of heteroplasmy, it is unknown whether mutations initiated in the mother are inherited, occur in utero, or occur and accumulate early in life. The purpose of this study is to examine the maternally heritable and de novo mutation rate in the fetal mtDNA through high-fidelity sequencing from a large population-based cohort. STUDY DESIGN Samples were obtained from 90 matched maternal (blood) and fetal (placental) pairs. In addition, a smaller cohort (n = 5) of maternal (blood), fetal (placental), and neonatal (cord blood) trios were subjected to DNA extraction and shotgun sequencing. The whole genome was sequenced on the Illumina HiSeq platform (Illumina Inc., San Diego, CA), and haplogroups and mtDNA variants were identified through mapping to reference mitochondrial genomes (NC_012920). RESULTS We observed 665 single nucleotide polymorphisms and 82 insertions-deletions variants identified in the cohort at large. We achieved high sequencing depth of the mtDNA to an average depth of 65X (range, 20-171X) coverage. The proportions of haplogroups identified in the cohort are consistent with the patient's self-identified ethnicity (>90% Hispanic), and all maternal-fetal pairs mapped to the identical haplogroup. Only variants from samples with average depth >20X and allele frequency >1% were included for further analysis. While the majority of the maternal-fetal pairs (>90%) demonstrated identical variants at the single nucleotide level, we observed rare mitochondrial single nucleotide polymorphism discordance between maternal and fetal mitochondrial genomes. CONCLUSION In this first in-depth sequencing analysis of mtDNA from maternal-fetal pairs at the time of birth, a low rate of de novo mutations appears in the fetal mitochondrial genome. This implies that these mutations likely arise from the maternal heteroplasmic pool (eg, in the oocyte), and accumulate later in the offspring's life. These findings have key implications for both the occurrence and screening for mitochondrial disorders.
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Giordano C, Morea V, Perli E, d'Amati G. The phenotypic expression of mitochondrial tRNA-mutations can be modulated by either mitochondrial leucyl-tRNA synthetase or the C-terminal domain thereof. Front Genet 2015; 6:113. [PMID: 25852750 PMCID: PMC4370040 DOI: 10.3389/fgene.2015.00113] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Accepted: 03/04/2015] [Indexed: 11/23/2022] Open
Abstract
Mutations in mitochondrial (mt) DNA determine important human diseases. The majority of the known pathogenic mutations are located in transfer RNA (tRNA) genes and are responsible for a wide range of currently untreatable disorders. Experimental evidence both in yeast and in human cells has shown that the detrimental effects of mt-tRNA point mutations can be attenuated by increasing the expression of the cognate mt-aminoacyl-tRNA synthetases (aaRSs). In addition, constitutive high levels of isoleucyl-tRNA syntethase have been shown to reduce the penetrance of a homoplasmic mutation in mt-tRNAIle in a small kindred. More recently, we showed that the isolated carboxy-terminal domain of human mt-leucyl tRNA synthetase (LeuRS-Cterm) localizes to mitochondria and ameliorates the energetic defect in transmitochondrial cybrids carrying mutations either in the cognate mt-tRNALeu(UUR) or in the non-cognate mt-tRNAIle gene. Since the mt-LeuRS-Cterm does not possess catalytic activity, its rescuing ability is most likely mediated by a chaperon-like effect, consisting in the stabilization of the tRNA structure altered by the mutation. All together, these observations open potential therapeutic options for mt-tRNA mutations-associated diseases.
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Affiliation(s)
- Carla Giordano
- Department of Radiological, Oncological and Pathological Sciences, Sapienza University of Rome Rome, Italy
| | - Veronica Morea
- National Research Council of Italy, Institute of Molecular Biology and Pathology, Department of Biochemical Sciences, Sapienza University of Rome Rome, Italy
| | - Elena Perli
- Department of Radiological, Oncological and Pathological Sciences, Sapienza University of Rome Rome, Italy
| | - Giulia d'Amati
- Department of Radiological, Oncological and Pathological Sciences, Sapienza University of Rome Rome, Italy ; Pasteur Institute-Cenci Bolognetti Foundation Rome, Italy
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36
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Kirchner S, Ignatova Z. Emerging roles of tRNA in adaptive translation, signalling dynamics and disease. Nat Rev Genet 2014; 16:98-112. [DOI: 10.1038/nrg3861] [Citation(s) in RCA: 355] [Impact Index Per Article: 35.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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37
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Brown A, Amunts A, Bai XC, Sugimoto Y, Edwards PC, Murshudov G, Scheres SHW, Ramakrishnan V. Structure of the large ribosomal subunit from human mitochondria. Science 2014; 346:718-722. [PMID: 25278503 DOI: 10.1126/science.1258026] [Citation(s) in RCA: 224] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Human mitochondrial ribosomes are highly divergent from all other known ribosomes and are specialized to exclusively translate membrane proteins. They are linked with hereditary mitochondrial diseases and are often the unintended targets of various clinically useful antibiotics. Using single-particle cryogenic electron microscopy, we have determined the structure of its large subunit to 3.4 angstrom resolution, revealing 48 proteins, 21 of which are specific to mitochondria. The structure unveils an adaptation of the exit tunnel for hydrophobic nascent peptides, extensive remodeling of the central protuberance, including recruitment of mitochondrial valine transfer RNA (tRNA(Val)) to play an integral structural role, and changes in the tRNA binding sites related to the unusual characteristics of mitochondrial tRNAs.
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Affiliation(s)
- Alan Brown
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
| | - Alexey Amunts
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
| | - Xiao-Chen Bai
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
| | - Yoichiro Sugimoto
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
| | - Patricia C Edwards
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
| | - Garib Murshudov
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
| | - Sjors H W Scheres
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
| | - V Ramakrishnan
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
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38
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Pathological Mutations of the Mitochondrial Human Genome: the Instrumental Role of the Yeast S. cerevisiae. Diseases 2014. [DOI: 10.3390/diseases2010024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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39
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Hornig-Do HT, Montanari A, Rozanska A, Tuppen HA, Almalki AA, Abg-Kamaludin DP, Frontali L, Francisci S, Lightowlers RN, Chrzanowska-Lightowlers ZM. Human mitochondrial leucyl tRNA synthetase can suppress non cognate pathogenic mt-tRNA mutations. EMBO Mol Med 2014; 6:183-93. [PMID: 24413189 PMCID: PMC3927954 DOI: 10.1002/emmm.201303202] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Disorders of the mitochondrial genome cause a wide spectrum of disease, these present mainly as neurological and/or muscle related pathologies. Due to the intractability of the human mitochondrial genome there are currently no effective treatments for these disorders. The majority of the pathogenic mutations lie in the genes encoding mitochondrial tRNAs. Consequently, the biochemical deficiency is due to mitochondrial protein synthesis defects, which manifest as aberrant cellular respiration and ATP synthesis. It has previously been reported that overexpression of mitochondrial aminoacyl tRNA synthetases has been effective, in cell lines, at partially suppressing the defects resulting from mutations in their cognate mt-tRNAs. We now show that leucyl tRNA synthetase is able to partially rescue defects caused by mutations in non-cognate mt-tRNAs. Further, a C terminal peptide alone can enter mitochondria and interact with the same spectrum of mt-tRNAs as the entire synthetase, in intact cells. These data support the possibility that a small peptide could correct at least the biochemical defect associated with many mt-tRNA mutations, inferring a novel therapy for these disorders.
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Affiliation(s)
- Hue Tran Hornig-Do
- The Wellcome Trust Centre for Mitochondrial Research Institute for Ageing and Health The Medical School, Newcastle University, Newcastle upon Tyne, UK
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40
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Mitochondrial DNA with a large-scale deletion causes two distinct mitochondrial disease phenotypes in mice. G3-GENES GENOMES GENETICS 2013; 3:1545-52. [PMID: 23853091 PMCID: PMC3755915 DOI: 10.1534/g3.113.007245] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Studies in patients have suggested that the clinical phenotypes of some mitochondrial diseases might transit from one disease to another (e.g., Pearson syndrome [PS] to Kearns-Sayre syndrome) in single individuals carrying mitochondrial (mt) DNA with a common deletion (∆mtDNA), but there is no direct experimental evidence for this. To determine whether ∆mtDNA has the pathologic potential to induce multiple mitochondrial disease phenotypes, we used trans-mitochondrial mice with a heteroplasmic state of wild-type mtDNA and ∆mtDNA (mito-mice∆). Late-stage embryos carrying ≥50% ∆mtDNA showed abnormal hematopoiesis and iron metabolism in livers that were partly similar to PS (PS-like phenotypes), although they did not express sideroblastic anemia that is a typical symptom of PS. More than half of the neonates with PS-like phenotypes died by 1 month after birth, whereas the rest showed a decrease of ∆mtDNA load in the affected tissues, peripheral blood and liver, and they recovered from PS-like phenotypes. The proportion of ∆mtDNA in various tissues of the surviving mito-mice∆ increased with time, and Kearns-Sayre syndrome−like phenotypes were expressed when the proportion of ∆mtDNA in various tissues reached >70–80%. Our model mouse study clearly showed that a single ∆mtDNA was responsible for at least two distinct disease phenotypes at different ages and suggested that the level and dynamics of ∆mtDNA load in affected tissues would be important for the onset and transition of mitochondrial disease phenotypes in mice.
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41
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DiMauro S. Mitochondrial encephalomyopathies--fifty years on: the Robert Wartenberg Lecture. Neurology 2013; 81:281-91. [PMID: 23858410 PMCID: PMC3959764 DOI: 10.1212/wnl.0b013e31829bfe89] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Accepted: 04/22/2013] [Indexed: 12/11/2022] Open
Affiliation(s)
- Salvatore DiMauro
- Department of Neurology, Columbia University Medical Center, New York, NY, USA.
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42
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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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43
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Abstract
Since the first description of a mitochondrial DNA (mtDNA)-associated disease in the late 1980s, there have been more than 275 mutations within the mtDNA genome described causing human disease. The phenotypic expression of these disorders is vast, as disturbances of the unique physiology of mitochondria can create a wide range of clinical heterogeneity. Features of heteroplasmy, threshold effect, genetic bottleneck, mtDNA depletion, mitotic segregation, and maternal inheritance have been identified and described as a result of novel biochemical and genetic controls of mitochondrial function. We hope that as we unfold this fascinating part of clinical medicine, the reader will see how alterations in the tapestry of mitochondrial biochemistry and genetics can give rise to human illness.
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Affiliation(s)
- Russell P Saneto
- Division of Pediatric Neurology, Seattle Children's Hospital/University of Washington, Seattle, WA 98105, USA.
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44
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Shakir AA, Turnbull DM, Adams JR. Management of patients with dental disease and mitochondrial disorders. ACTA ACUST UNITED AC 2013; 39:654-5. [PMID: 23479854 DOI: 10.12968/denu.2012.39.9.654] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
UNLABELLED This case report describes dental disease associated with mitochondrial disease (Leigh's disease) in a young adult. Normal preventive dentistry is difficult in these groups of patients and often leads to management required in secondary care. An awareness of the background pathology is needed when managing these groups of patients. Management of dental pathology in this particular patient often required input from other specialties to ensure a successful outcome. CLINICAL RELEVANCE To raise awareness of the dental pathologies patients with mitochondrial disease may experience as they present to the general dental practitioner, and what treatments may be appropriate.
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Affiliation(s)
- Adam A Shakir
- Department of Oral and Maxillofacial Surgery, Newcastle General Hospital, UK
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45
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Villar P, Bretón B, García-Pavía P, González-Páramos C, Blázquez A, Gómez-Bueno M, García-Silva T, García-Consuegra I, Martín MA, Garesse R, Bornstein B, Gallardo ME. Cardiac Dysfunction in Mitochondrial Disease. Circ J 2013; 77:2799-806. [DOI: 10.1253/circj.cj-13-0557] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Pedro Villar
- Biochemistry Unit, “Hospital Universitario Puerta de Hierro”
- Research Institute “Puerta de Hierro” Majadahonda (IDIPHIM)
| | - Begoña Bretón
- Biochemistry Unit, “Hospital Universitario Puerta de Hierro”
- Research Institute “Puerta de Hierro” Majadahonda (IDIPHIM)
| | - Pablo García-Pavía
- Cardiology Unit, “Hospital Universitario Puerta de Hierro”
- Net of Clinical and Basic Research in Heart Failure (REDINSCOR)
- Research Institute “Puerta de Hierro” Majadahonda (IDIPHIM)
| | | | - Alberto Blázquez
- Rare Diseases Biomedical Research Centre (CIBERER)
- Health Research Institute “Hospital 12 de Octubre (i+12)”
- Laboratory of Mitochondrial Diseases, Research Centre
| | - Manuel Gómez-Bueno
- Cardiology Unit, “Hospital Universitario Puerta de Hierro”
- Net of Clinical and Basic Research in Heart Failure (REDINSCOR)
- Research Institute “Puerta de Hierro” Majadahonda (IDIPHIM)
| | - Teresa García-Silva
- Health Research Institute “Hospital 12 de Octubre (i+12)”
- Pediatrics Unit, “Hospital Universitario 12 de Octubre”
| | - Ines García-Consuegra
- Health Research Institute “Hospital 12 de Octubre (i+12)”
- Laboratory of Mitochondrial Diseases, Research Centre
| | - Miguel Angel Martín
- Rare Diseases Biomedical Research Centre (CIBERER)
- Health Research Institute “Hospital 12 de Octubre (i+12)”
- Laboratory of Mitochondrial Diseases, Research Centre
| | - Rafael Garesse
- Biochemistry Departament, Biomedical Research Institute “Alberto Sols”, Medicine College, UAM-CSIC
- Rare Diseases Biomedical Research Centre (CIBERER)
- Health Research Institute “Hospital 12 de Octubre (i+12)”
| | - Belen Bornstein
- Biochemistry Departament, Biomedical Research Institute “Alberto Sols”, Medicine College, UAM-CSIC
- Rare Diseases Biomedical Research Centre (CIBERER)
- Health Research Institute “Hospital 12 de Octubre (i+12)”
- Biochemistry Unit, “Hospital Universitario Puerta de Hierro”
- Research Institute “Puerta de Hierro” Majadahonda (IDIPHIM)
| | - M. Esther Gallardo
- Biochemistry Departament, Biomedical Research Institute “Alberto Sols”, Medicine College, UAM-CSIC
- Rare Diseases Biomedical Research Centre (CIBERER)
- Health Research Institute “Hospital 12 de Octubre (i+12)”
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46
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Abstract
The progress of molecular genetics helps clinicians to prove or exclude a suspected diagnosis for a vast and yet increasing number of genodermatoses. This leads to precise genetic counselling, prenatal diagnosis and preimplantation genetic haplotyping for many inherited skin conditions. It is also helpful in such occasions as phenocopy, late onset and incomplete penetrance, uniparental disomy, mitochondrial inheritance and pigmentary mosaicism. Molecular methods of two genodermatoses are explained in detail, i.e. genodermatoses with skin fragility and neurofibromatosis type 1.
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Affiliation(s)
- Vesarat Wessagowit
- Molecular Genetics Laboratory, The Institute of Dermatology, Bangkok, Thailand.
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47
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Sangatsuda Y, Nakamura M, Tomiyasu A, Deguchi A, Toyota Y, Goto YI, Nishino I, Ueno SI, Sano A. Heteroplasmic m.1624C>T mutation of the mitochondrial tRNA(Val) gene in a proband and his mother with repeated consciousness disturbances. Mitochondrion 2012; 12:617-22. [PMID: 23063709 DOI: 10.1016/j.mito.2012.10.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Revised: 09/03/2012] [Accepted: 10/02/2012] [Indexed: 10/27/2022]
Abstract
Homoplasmic m.1624C>T mutation of the mitochondrial tRNA(Val) gene was previously demonstrated to cause fatal neonatal Leigh syndrome. Here, we report the clinical phenotypes of a Japanese male and his mother with heteroplasmic m.1624C>T mutation. The 36-year-old male presented with repeated episodes of consciousness disturbance since the age of 25, cognitive decline, and personality change. Cerebrospinal fluid levels of lactate and pyruvate were elevated. His mother showed similar symptoms and course. The mutation m.1624C>T was identified heteroplasmically in the proband's muscle and leukocytes and in the mother's leukocytes. The heteroplasmy load decreased with age.
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Affiliation(s)
- Yoko Sangatsuda
- Department of Psychiatry, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8520, Japan.
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48
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Elson JL, Sweeney MG, Procaccio V, Yarham JW, Salas A, Kong QP, van der Westhuizen FH, Pitceathly RDS, Thorburn DR, Lott MT, Wallace DC, Taylor RW, McFarland R. Toward a mtDNA locus-specific mutation database using the LOVD platform. Hum Mutat 2012; 33:1352-8. [PMID: 22581690 DOI: 10.1002/humu.22118] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Accepted: 04/26/2012] [Indexed: 12/12/2022]
Abstract
The Human Variome Project (HVP) is a global effort to collect and curate all human genetic variation affecting health. Mutations of mitochondrial DNA (mtDNA) are an important cause of neurogenetic disease in humans; however, identification of the pathogenic mutations responsible can be problematic. In this article, we provide explanations as to why and suggest how such difficulties might be overcome. We put forward a case in support of a new Locus Specific Mutation Database (LSDB) implemented using the Leiden Open-source Variation Database (LOVD) system that will not only list primary mutations, but also present the evidence supporting their role in disease. Critically, we feel that this new database should have the capacity to store information on the observed phenotypes alongside the genetic variation, thereby facilitating our understanding of the complex and variable presentation of mtDNA disease. LOVD supports fast queries of both seen and hidden data and allows storage of sequence variants from high-throughput sequence analysis. The LOVD platform will allow construction of a secure mtDNA database; one that can fully utilize currently available data, as well as that being generated by high-throughput sequencing, to link genotype with phenotype enhancing our understanding of mitochondrial disease, with a view to providing better prognostic information.
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Affiliation(s)
- Joanna L Elson
- Mitochondrial Research Group, Institute for Ageing and Health, The Medical School, Newcastle University, Newcastle upon Tyne, United Kingdom.
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49
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del Mar O'Callaghan M, Emperador S, López-Gallardo E, Jou C, Buján N, Montero R, Garcia-Cazorla A, Gonzaga D, Ferrer I, Briones P, Ruiz-Pesini E, Pineda M, Artuch R, Montoya J. New mitochondrial DNA mutations in tRNA associated with three severe encephalopamyopathic phenotypes: neonatal, infantile, and childhood onset. Neurogenetics 2012; 13:245-50. [PMID: 22638997 DOI: 10.1007/s10048-012-0322-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2012] [Accepted: 03/10/2012] [Indexed: 01/03/2023]
Abstract
The reported cases showed clinical, biochemical, histopathological, and molecular features lending support to the hypothesis of a pathogenic effect of the detected mutations. Case 1 was a neonatal presentation who showed multiple mitochondrial respiratory chain enzyme defects in muscle associated with a new homoplasmic m.5514A > G transition in the tRNA(Trp) gene. Case 2 was a late infantile presentation who also showed mitochondrial respiratory chain enzyme deficiencies in muscle together with a new m.1643A > G tRNA(Val) mutation in homoplasmy. Case 3 showed a MERRF phenotype presented in childhood associated with the once previously reported m.15923A > G mutation in heteroplasmy in all the tissues studied.
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Affiliation(s)
- María del Mar O'Callaghan
- Department of Pediatric Neurology, Hospital Sant Joan de Déu, Passeig Sant Joan de Déu 2, 08950 Esplugues, Barcelona, Spain.
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50
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Lee IC, El-Hattab AW, Wang J, Li FY, Weng SW, Craigen WJ, Wong LJC. SURF1-associated leigh syndrome: A case series and novel mutations. Hum Mutat 2012; 33:1192-200. [DOI: 10.1002/humu.22095] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2011] [Accepted: 03/15/2012] [Indexed: 11/11/2022]
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