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Liu Y, Cai L, Wang H, Yao L, Zhang K, Chen G, Zhou Y. Novel mitochondrial-related gene signature predicts prognosis and immunological status in glioma. Transl Cancer Res 2024; 13:3338-3353. [PMID: 39145059 PMCID: PMC11319993 DOI: 10.21037/tcr-23-2072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Accepted: 06/04/2024] [Indexed: 08/16/2024]
Abstract
Background Mitochondria are the center of cellular metabolism. The relationship between mitochondria and diseases has also been studied for a long time. However, the prognostic role of mitochondrial-related genes (MRGs) in patients with glioma and their biological effects are still unclear. The aim of the study was to construct a mitochondria-related model to assess prognosis and potential biological effects like immune infiltration, gene pathway and mutation, and give some predictive chemotherapeutic agents. Methods The data of 675 patients from The Cancer Genome Atlas (TCGA) database were used to identify MRG signature and construct a prognostic model. After validating its robustness in Chinese Glioma Genome Atlas (CGGA), two risk groups derived from the prognostic model were then conducted with Gene Set Enrichment Analysis (GSEA), immune status, mutation status and chemotherapeutic agents prediction. Results The prognostic model built from six gene signatures can successfully predict the prognosis and reflect clinicopathological characteristics. Patients in high-risk group displayed significantly worse overall survival (OS), immunosuppression effects, and mutation markers with worse prognosis. Twelve chemotherapeutic agents with strongly correlated sensitivity and risk scores were selected as potential agents. Conclusions The novel MRG signatures (TYMP, TSFM, MGME1, BOLA3, TRMT5, NDUFA9) can predict prognosis and immunological status in glioma.
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Affiliation(s)
- Yongsheng Liu
- Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Lize Cai
- Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Hao Wang
- Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Lin Yao
- Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Kai Zhang
- Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Guangliang Chen
- Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Youxin Zhou
- Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, China
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2
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Zhang X, Zhang G, Cao L, Zhou W, Tan C, Ma S, Yang J. Two novel SUCLA2 variants cause mitochondrial DNA depletion syndrome, type 5 in two siblings. Front Neurol 2024; 15:1394150. [PMID: 39070054 PMCID: PMC11273780 DOI: 10.3389/fneur.2024.1394150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Accepted: 07/03/2024] [Indexed: 07/30/2024] Open
Abstract
Mitochondrial DNA depletion syndrome (MDS), characterized by succinate-CoA ligase deficiency and loss of mitochondrial DNA (mtDNA), is caused by specific variants in nuclear genes responsible for mtDNA maintenance. SUCLA2-related mitochondrial DNA depletion syndrome, type 5 (MTDPS-5), presents as a rare, severe early progressive encephalomyopathy. This report investigates a new family exhibiting clinical manifestations of MTDPS-5 and elucidates the genetic basis of this disorder. In two affected siblings, a novel maternally inherited nonsense variant [c.1234C>T (p.Arg412*)] in the SUCLA2 gene and a unique paternally inherited indel variant (g.48569263-48571020del1758insATGA) were identified. Additionally, the siblings exhibited blood mtDNA content lower than 33% compared to age-matched controls. These findings underscore the importance of assessing SUCLA2 variants in patients with severe early progressive encephalomyopathy, even in the absence of methylmalonic aciduria or mtDNA loss, thereby broaden the mutational spectrum of this gene.
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Affiliation(s)
- Xiaohuan Zhang
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Center of Medical Genetics, Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
- Research Unit for Blindness Prevention of Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences, Chengdu, China
| | - Guo Zhang
- Dean’s Office, Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
| | - Li Cao
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Center of Medical Genetics, Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
- Research Unit for Blindness Prevention of Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences, Chengdu, China
| | - Wenjing Zhou
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Center of Medical Genetics, Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
- Research Unit for Blindness Prevention of Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences, Chengdu, China
| | - Chang Tan
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Center of Medical Genetics, Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
- Research Unit for Blindness Prevention of Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences, Chengdu, China
| | - Shi Ma
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Center of Medical Genetics, Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
- Research Unit for Blindness Prevention of Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences, Chengdu, China
| | - Jiyun Yang
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Center of Medical Genetics, Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
- Research Unit for Blindness Prevention of Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences, Chengdu, China
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3
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Bernardino Gomes TM, Vincent AE, Menger KE, Stewart JB, Nicholls TJ. Mechanisms and pathologies of human mitochondrial DNA replication and deletion formation. Biochem J 2024; 481:683-715. [PMID: 38804971 PMCID: PMC11346376 DOI: 10.1042/bcj20230262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Revised: 05/13/2024] [Accepted: 05/14/2024] [Indexed: 05/29/2024]
Abstract
Human mitochondria possess a multi-copy circular genome, mitochondrial DNA (mtDNA), that is essential for cellular energy metabolism. The number of copies of mtDNA per cell, and their integrity, are maintained by nuclear-encoded mtDNA replication and repair machineries. Aberrant mtDNA replication and mtDNA breakage are believed to cause deletions within mtDNA. The genomic location and breakpoint sequences of these deletions show similar patterns across various inherited and acquired diseases, and are also observed during normal ageing, suggesting a common mechanism of deletion formation. However, an ongoing debate over the mechanism by which mtDNA replicates has made it difficult to develop clear and testable models for how mtDNA rearrangements arise and propagate at a molecular and cellular level. These deletions may impair energy metabolism if present in a high proportion of the mtDNA copies within the cell, and can be seen in primary mitochondrial diseases, either in sporadic cases or caused by autosomal variants in nuclear-encoded mtDNA maintenance genes. These mitochondrial diseases have diverse genetic causes and multiple modes of inheritance, and show notoriously broad clinical heterogeneity with complex tissue specificities, which further makes establishing genotype-phenotype relationships challenging. In this review, we aim to cover our current understanding of how the human mitochondrial genome is replicated, the mechanisms by which mtDNA replication and repair can lead to mtDNA instability in the form of large-scale rearrangements, how rearranged mtDNAs subsequently accumulate within cells, and the pathological consequences when this occurs.
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Affiliation(s)
- Tiago M. Bernardino Gomes
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, U.K
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, U.K
- NHS England Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne NE2 4HH, U.K
| | - Amy E. Vincent
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, U.K
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, U.K
| | - Katja E. Menger
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, U.K
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, U.K
| | - James B. Stewart
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, U.K
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, U.K
| | - Thomas J. Nicholls
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, U.K
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, U.K
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4
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Vincent AE, Chen C, Gomes TB, Di Leo V, Laalo T, Pabis K, Capaldi R, Marusich MF, McDonald D, Filby A, Fuller A, Lehmann Urban D, Zierz S, Deschauer M, Turnbull D, Reeve AK, Lawless C. A stagewise response to mitochondrial dysfunction in mitochondrial DNA maintenance disorders. Biochim Biophys Acta Mol Basis Dis 2024; 1870:167131. [PMID: 38521420 DOI: 10.1016/j.bbadis.2024.167131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 03/13/2024] [Accepted: 03/15/2024] [Indexed: 03/25/2024]
Abstract
Mitochondrial DNA (mtDNA) deletions which clonally expand in skeletal muscle of patients with mtDNA maintenance disorders, impair mitochondrial oxidative phosphorylation dysfunction. Previously we have shown that these mtDNA deletions arise and accumulate in perinuclear mitochondria causing localised mitochondrial dysfunction before spreading through the muscle fibre. We believe that mito-nuclear signalling is a key contributor in the accumulation and spread of mtDNA deletions, and that knowledge of how muscle fibres respond to mitochondrial dysfunction is key to our understanding of disease mechanisms. To understand the contribution of mito-nuclear signalling to the spread of mitochondrial dysfunction, we use imaging mass cytometry. We characterise the levels of mitochondrial Oxidative Phosphorylation proteins alongside a mitochondrial mass marker, in a cohort of patients with mtDNA maintenance disorders. Our expanded panel included protein markers of key signalling pathways, allowing us to investigate cellular responses to different combinations of oxidative phosphorylation dysfunction and ragged red fibres. We find combined Complex I and IV deficiency to be most common. Interestingly, in fibres deficient for one or more complexes, the remaining complexes are often upregulated beyond the increase of mitochondrial mass typically observed in ragged red fibres. We further find that oxidative phosphorylation deficient fibres exhibit an increase in the abundance of proteins involved in proteostasis, e.g. HSP60 and LONP1, and regulation of mitochondrial metabolism (including oxidative phosphorylation and proteolysis, e.g. PHB1). Our analysis suggests that the cellular response to mitochondrial dysfunction changes depending on the combination of deficient oxidative phosphorylation complexes in each fibre.
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Affiliation(s)
- Amy E Vincent
- Wellcome Centre for Mitochondrial Research, Clinical and Translational Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle, UK; NIHR Biomedical Research Centre, Faculty of Medical Sciences, Newcastle University, Newcastle, UK; John Walton Muscular Dystrophy Research Centre, Clinical and Translational Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle, UK.
| | - Chun Chen
- Wellcome Centre for Mitochondrial Research, Bioscience Institute, Faculty of Medical Sciences, Newcastle University, Newcastle, UK
| | - Tiago Bernardino Gomes
- Wellcome Centre for Mitochondrial Research, Clinical and Translational Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle, UK; NIHR Biomedical Research Centre, Faculty of Medical Sciences, Newcastle University, Newcastle, UK
| | - Valeria Di Leo
- Wellcome Centre for Mitochondrial Research, Clinical and Translational Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle, UK
| | - Tuomas Laalo
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Kamil Pabis
- Wellcome Centre for Mitochondrial Research, Clinical and Translational Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle, UK
| | | | | | - David McDonald
- Innovation, Methodology and Application Research Theme, Biosciences Institute, Newcastle University, Newcastle upon Tyne, UK; Flow Cytometry Core Facility, Faculty of Medical Sciences, Newcastle University, Newcastle, UK
| | - Andrew Filby
- Innovation, Methodology and Application Research Theme, Biosciences Institute, Newcastle University, Newcastle upon Tyne, UK; Flow Cytometry Core Facility, Faculty of Medical Sciences, Newcastle University, Newcastle, UK
| | - Andrew Fuller
- Innovation, Methodology and Application Research Theme, Biosciences Institute, Newcastle University, Newcastle upon Tyne, UK; Flow Cytometry Core Facility, Faculty of Medical Sciences, Newcastle University, Newcastle, UK
| | | | - Stephan Zierz
- Department of Neurology, Martin-Luther-University Halle-Wittenberg, Halle/Saale, Germany
| | - Marcus Deschauer
- Department of Neurology, Technical University Munich, Munich, Germany
| | - Doug Turnbull
- Wellcome Centre for Mitochondrial Research, Clinical and Translational Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle, UK
| | - Amy K Reeve
- Wellcome Centre for Mitochondrial Research, Clinical and Translational Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle, UK
| | - Conor Lawless
- Wellcome Centre for Mitochondrial Research, Clinical and Translational Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle, UK; NIHR Biomedical Research Centre, Faculty of Medical Sciences, Newcastle University, Newcastle, UK
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5
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Manzoni E, Carli S, Gaignard P, Schlieben LD, Hirano M, Ronchi D, Gonzales E, Shimura M, Murayama K, Okazaki Y, Barić I, Petkovic Ramadza D, Karall D, Mayr J, Martinelli D, La Morgia C, Primiano G, Santer R, Servidei S, Bris C, Cano A, Furlan F, Gasperini S, Laborde N, Lamperti C, Lenz D, Mancuso M, Montano V, Menni F, Musumeci O, Nesbitt V, Procopio E, Rouzier C, Staufner C, Taanman JW, Tal G, Ticci C, Cordelli DM, Carelli V, Procaccio V, Prokisch H, Garone C. Deoxyguanosine kinase deficiency: natural history and liver transplant outcome. Brain Commun 2024; 6:fcae160. [PMID: 38756539 PMCID: PMC11098040 DOI: 10.1093/braincomms/fcae160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 03/25/2024] [Accepted: 05/03/2024] [Indexed: 05/18/2024] Open
Abstract
Autosomal recessive pathogenetic variants in the DGUOK gene cause deficiency of deoxyguanosine kinase activity and mitochondrial deoxynucleotides pool imbalance, consequently, leading to quantitative and/or qualitative impairment of mitochondrial DNA synthesis. Typically, patients present early-onset liver failure with or without neurological involvement and a clinical course rapidly progressing to death. This is an international multicentre study aiming to provide a retrospective natural history of deoxyguanosine kinase deficient patients. A systematic literature review from January 2001 to June 2023 was conducted. Physicians of research centres or clinicians all around the world caring for previously reported patients were contacted to provide followup information or additional clinical, biochemical, histological/histochemical, and molecular genetics data for unreported cases with a confirmed molecular diagnosis of deoxyguanosine kinase deficiency. A cohort of 202 genetically confirmed patients, 36 unreported, and 166 from a systematic literature review, were analyzed. Patients had a neonatal onset (≤ 1 month) in 55.7% of cases, infantile (>1 month and ≤ 1 year) in 32.3%, pediatric (>1 year and ≤18 years) in 2.5% and adult (>18 years) in 9.5%. Kaplan-Meier analysis showed statistically different survival rates (P < 0.0001) among the four age groups with the highest mortality for neonatal onset. Based on the clinical phenotype, we defined four different clinical subtypes: hepatocerebral (58.8%), isolated hepatopathy (21.9%), hepatomyoencephalopathy (9.6%), and isolated myopathy (9.6%). Muscle involvement was predominant in adult-onset cases whereas liver dysfunction causes morbidity and mortality in early-onset patients with a median survival of less than 1 year. No genotype-phenotype correlation was identified. Liver transplant significantly modified the survival rate in 26 treated patients when compared with untreated. Only six patients had additional mild neurological signs after liver transplant. In conclusion, deoxyguanosine kinase deficiency is a disease spectrum with a prevalent liver and brain tissue specificity in neonatal and infantile-onset patients and muscle tissue specificity in adult-onset cases. Our study provides clinical, molecular genetics and biochemical data for early diagnosis, clinical trial planning and immediate intervention with liver transplant and/or nucleoside supplementation.
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Affiliation(s)
- Eleonora Manzoni
- Department of Medical and Surgical Sciences, Alma Mater Studiorum University of Bologna, Bologna 40138, Italy
- IRCCS Istituto delle Scienze Neurologiche, UO Neuropsichiatria dell’età Pediatrica di Bologna, Bologna 40124, Italy
| | - Sara Carli
- Department of Medical and Surgical Sciences, Alma Mater Studiorum University of Bologna, Bologna 40138, Italy
| | - Pauline Gaignard
- Department of Biochemistry, Bicêtre Hospital, Reference Center for Mitochondrial Disease, University of Paris-Saclay, Assistance Publique-Hôpitaux de Paris, Paris 94275, France
| | - Lea Dewi Schlieben
- School of Medicine, Institute of Human Genetics, Technical University of Munich, Munich, 80333 Germany
- Institute of Neurogenomics, Computational Health Center, Helmholtz Zentrum München, Neuherberg 80333, Germany
| | - Michio Hirano
- H. Houston Merritt Neuromuscular Research Center, Department of Neurology, Columbia University Irving Medical Center, New York, NY 10033, USA
| | - Dario Ronchi
- Dino Ferrari Center, Department of Pathophysiology and Transplantation, University of Milan, Milan 20122, Italy
| | - Emmanuel Gonzales
- Pediatric Hepatology and Pediatric Liver Transplantation Unit, Bicêtre Hospital, Reference Center for Mitochondrial Disease, University of Paris-Saclay, Assistance Publique-Hôpitaux de Paris, Paris 94270, France
| | - Masaru Shimura
- Center for Medical Genetics, Department of Metabolism, Chiba Children’s Hospital, Chiba 260-0842, Japan
| | - Kei Murayama
- Center for Medical Genetics, Department of Metabolism, Chiba Children’s Hospital, Chiba 260-0842, Japan
- Diagnostics and Therapeutic of Intractable Diseases, Intractable Disease Research Center, Graduate School of Medicine, Juntendo University, Tokyo 113-8421, Japan
| | - Yasushi Okazaki
- Diagnostics and Therapeutic of Intractable Diseases, Intractable Disease Research Center, Graduate School of Medicine, Juntendo University, Tokyo 113-8421, Japan
| | - Ivo Barić
- Department of Pediatrics, University Hospital Centre Zagreb and University of Zagreb, School of Medicine, Zagreb 10000, Croatia
| | - Danijela Petkovic Ramadza
- Department of Pediatrics, University Hospital Centre Zagreb and University of Zagreb, School of Medicine, Zagreb 10000, Croatia
| | - Daniela Karall
- Clinic for Pediatrics, Division of Inherited Metabolic Disorders, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Johannes Mayr
- University Children’s Hospital, Paracelsus Medical University (PMU), 5020 Salzburg, Austria
| | - Diego Martinelli
- Division of Metabolism, Bambino Gesù Children’s Hospital IRCCS, Rome 00165, Italy
| | - Chiara La Morgia
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna 40123, Italy
- IRCCS Istituto di Scienze Neurologiche di Bologna, Programma di Neurogenetica, Bologna 40124, Italy
| | - Guido Primiano
- Dipartimento di Neuroscienze, Organi di Senso e Torace -Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Rome 00136, Italy
- Dipartimento Di Neuroscienze, Università Cattolica del Sacro Cuore, Rome 00168, Italy
| | - René Santer
- Department of Pediatrics, University Medical Center Eppendorf, Hamburg 20246, Germany
| | - Serenella Servidei
- Dipartimento di Neuroscienze, Organi di Senso e Torace -Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Rome 00136, Italy
- Dipartimento Di Neuroscienze, Università Cattolica del Sacro Cuore, Rome 00168, Italy
| | - Céline Bris
- University Angers, Angers Hospital, INSERM, CNRS, MITOVASC, SFR ICAT, Angers F-49000, France
| | - Aline Cano
- Centre de référence des maladies héréditaires du métabolisme, CHU la Timone Enfants, Marseille 13005, France
| | - Francesca Furlan
- Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Regional Clinical Center for Expanded Newborn Screening, Milan 20122, Italy
| | - Serena Gasperini
- Department of Pediatrics, Fondazione IRCCS San Gerardo dei Tintori, 20900 Monza, Italy
| | - Nolwenn Laborde
- Unité de Gastroentérologie, Hépatologie, Nutrition et Maladies Héréditaires du Métabolisme, Hôpital des Enfants, CHU de Toulouse, Toulouse 31300, France
| | - Costanza Lamperti
- Division of Medical Genetics and Neurogenetics, Fondazione IRCCS Neurological Institute ‘C. Besta’, Milan 20133, Italy
| | - Dominic Lenz
- Division of Neuropaediatrics and Paediatric Metabolic Medicine, Center for Paediatric and Adolescent Medicine, University Hospital Heidelberg, Heidelberg 69120, Germany
| | - Michelangelo Mancuso
- Department of Clinical and Experimental Medicine, Neurological Institute, University of Pisa & AOUP, Pisa 56126, Italy
| | - Vincenzo Montano
- Department of Clinical and Experimental Medicine, Neurological Institute, University of Pisa & AOUP, Pisa 56126, Italy
| | - Francesca Menni
- Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Regional Clinical Center for Expanded Newborn Screening, Milan 20122, Italy
| | - Olimpia Musumeci
- Unit of Neurology and Neuromuscular Disorders, Department of Clinical and Experimental Medicine, University of Messina, Messina 98125, Italy
| | - Victoria Nesbitt
- Department of Paediatrics, Medical Sciences Division, Oxford University, Oxford OX3 9DU, UK
| | - Elena Procopio
- Metabolic Unit, Meyer Children’s Hospital IRCCS, Florence 50139, Italy
| | - Cécile Rouzier
- Centre de référence des Maladies Mitochondriales, Service de Génétique Médicale, CHU de Nice, Université Côte d’Azur, CNRS, INSERM, IRCAN, Nice 06000, France
| | - Christian Staufner
- Division of Neuropaediatrics and Paediatric Metabolic Medicine, Center for Paediatric and Adolescent Medicine, University Hospital Heidelberg, Heidelberg 69120, Germany
| | - Jan-Willem Taanman
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK
| | - Galit Tal
- Metabolic Clinic, Ruth Rappaport Children's Hospital, Rambam Health Care Campus, Haifa 3109601, Israel
- The Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 3109601, Israel
| | - Chiara Ticci
- Metabolic Unit, Meyer Children’s Hospital IRCCS, Florence 50139, Italy
| | - Duccio Maria Cordelli
- Department of Medical and Surgical Sciences, Alma Mater Studiorum University of Bologna, Bologna 40138, Italy
- IRCCS Istituto delle Scienze Neurologiche, UO Neuropsichiatria dell’età Pediatrica di Bologna, Bologna 40124, Italy
| | - Valerio Carelli
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna 40123, Italy
- IRCCS Istituto di Scienze Neurologiche di Bologna, Programma di Neurogenetica, Bologna 40124, Italy
| | - Vincent Procaccio
- University Angers, Angers Hospital, INSERM, CNRS, MITOVASC, SFR ICAT, Angers F-49000, France
| | - Holger Prokisch
- School of Medicine, Institute of Human Genetics, Technical University of Munich, Munich, 80333 Germany
- Institute of Neurogenomics, Computational Health Center, Helmholtz Zentrum München, Neuherberg 80333, Germany
| | - Caterina Garone
- Department of Medical and Surgical Sciences, Alma Mater Studiorum University of Bologna, Bologna 40138, Italy
- IRCCS Istituto delle Scienze Neurologiche, UO Neuropsichiatria dell’età Pediatrica di Bologna, Bologna 40124, Italy
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6
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Mao EYC, Yen HY, Wu CC. Structural basis of how MGME1 processes DNA 5' ends to maintain mitochondrial genome integrity. Nucleic Acids Res 2024; 52:4067-4078. [PMID: 38471810 DOI: 10.1093/nar/gkae186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Revised: 02/29/2024] [Accepted: 03/05/2024] [Indexed: 03/14/2024] Open
Abstract
Mitochondrial genome maintenance exonuclease 1 (MGME1) helps to ensure mitochondrial DNA (mtDNA) integrity by serving as an ancillary 5'-exonuclease for DNA polymerase γ. Curiously, MGME1 exhibits unique bidirectionality in vitro, being capable of degrading DNA from either the 5' or 3' end. The structural basis of this bidirectionally and, particularly, how it processes DNA from the 5' end to assist in mtDNA maintenance remain unclear. Here, we present a crystal structure of human MGME1 in complex with a 5'-overhang DNA, revealing that MGME1 functions as a rigid DNA clamp equipped with a single-strand (ss)-selective arch, allowing it to slide on single-stranded DNA in either the 5'-to-3' or 3'-to-5' direction. Using a nuclease activity assay, we have dissected the structural basis of MGME1-derived DNA cleavage patterns in which the arch serves as a ruler to determine the cleavage site. We also reveal that MGME1 displays partial DNA-unwinding ability that helps it to better resolve 5'-DNA flaps, providing insights into MGME1-mediated 5'-end processing of nascent mtDNA. Our study builds on previously solved MGME1-DNA complex structures, finally providing the comprehensive functional mechanism of this bidirectional, ss-specific exonuclease.
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Affiliation(s)
- Eric Y C Mao
- Department of Chemistry, College of Science, National Cheng Kung University, Tainan City 701, Taiwan
| | - Han-Yi Yen
- Department of Biochemistry and Molecular Biology, College of Medicine, National Cheng Kung University, Tainan City 701, Taiwan
| | - Chyuan-Chuan Wu
- Department of Biochemistry and Molecular Biology, College of Medicine, National Cheng Kung University, Tainan City 701, Taiwan
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7
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Fragkoulis G, Hangas A, Fekete Z, Michell C, Moraes C, Willcox S, Griffith JD, Goffart S, Pohjoismäki JO. Linear DNA-driven recombination in mammalian mitochondria. Nucleic Acids Res 2024; 52:3088-3105. [PMID: 38300793 PMCID: PMC11014290 DOI: 10.1093/nar/gkae040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 01/11/2024] [Indexed: 02/03/2024] Open
Abstract
Mitochondrial DNA (mtDNA) recombination in animals has remained enigmatic due to its uniparental inheritance and subsequent homoplasmic state, which excludes the biological need for genetic recombination, as well as limits tools to study it. However, molecular recombination is an important genome maintenance mechanism for all organisms, most notably being required for double-strand break repair. To demonstrate the existence of mtDNA recombination, we took advantage of a cell model with two different types of mitochondrial genomes and impaired its ability to degrade broken mtDNA. The resulting excess of linear DNA fragments caused increased formation of cruciform mtDNA, appearance of heterodimeric mtDNA complexes and recombinant mtDNA genomes, detectable by Southern blot and by long range PacBio® HiFi sequencing approach. Besides utilizing different electrophoretic methods, we also directly observed molecular complexes between different mtDNA haplotypes and recombination intermediates using transmission electron microscopy. We propose that the known copy-choice recombination by mitochondrial replisome could be sufficient for the needs of the small genome, thus removing the requirement for a specialized mitochondrial recombinase. The error-proneness of this system is likely to contribute to the formation of pathological mtDNA rearrangements.
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Affiliation(s)
- Georgios Fragkoulis
- Department of Environmental and Biological Sciences, University of Eastern Finland, PO Box 111, 80101 Joensuu, Finland
| | - Anu Hangas
- Department of Environmental and Biological Sciences, University of Eastern Finland, PO Box 111, 80101 Joensuu, Finland
| | - Zsófia Fekete
- Department of Environmental and Biological Sciences, University of Eastern Finland, PO Box 111, 80101 Joensuu, Finland
- Department of Genetics and Genomics, Institute of Genetics and Biotechnology, Hungarian University of Agriculture and Life Sciences, Gödöllő, Hungary
- Doctoral School of Animal Biotechnology and Animal Science, Hungarian University of Agriculture and Life Sciences, Gödöllő, Hungary
| | - Craig Michell
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Carlos T Moraes
- Department of Neurology, University of Miami Miller School of Medicine, Miami,FL, USA
| | - Smaranda Willcox
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, USA
| | - Jack D Griffith
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, USA
| | - Steffi Goffart
- Department of Environmental and Biological Sciences, University of Eastern Finland, PO Box 111, 80101 Joensuu, Finland
| | - Jaakko L O Pohjoismäki
- Department of Environmental and Biological Sciences, University of Eastern Finland, PO Box 111, 80101 Joensuu, Finland
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8
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Gonzalez CD, Nissanka N, Van Booven D, Griswold AJ, Moraes CT. Absence of both MGME1 and POLG EXO abolishes mtDNA whereas absence of either creates unique mtDNA duplications. J Biol Chem 2024; 300:107128. [PMID: 38432635 PMCID: PMC11002302 DOI: 10.1016/j.jbc.2024.107128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 02/21/2024] [Accepted: 02/23/2024] [Indexed: 03/05/2024] Open
Abstract
Both POLG and MGME1 are needed for mitochondrial DNA (mtDNA) maintenance in animal cells. POLG, the primary replicative polymerase of the mitochondria, has an exonuclease activity (3'→5') that corrects for the misincorporation of bases. MGME1 serves as an exonuclease (5'→3'), producing ligatable DNA ends. Although both have a critical role in mtDNA replication and elimination of linear fragments, these mechanisms are still not fully understood. Using digital PCR to evaluate and compare mtDNA integrity, we show that Mgme1 knock out (Mgme1 KK) tissue mtDNA is more fragmented than POLG exonuclease-deficient "Mutator" (Polg MM) or WT tissue. In addition, next generation sequencing of mutant hearts showed abundant duplications in/nearby the D-loop region and unique 100 bp duplications evenly spaced throughout the genome only in Mgme1 KK hearts. However, despite these unique mtDNA features at steady-state, we observed a similar delay in the degradation of mtDNA after an induced double strand DNA break in both Mgme1 KK and Polg MM models. Lastly, we characterized double mutant (Polg MM/Mgme1 KK) cells and show that mtDNA cannot be maintained without at least one of these enzymatic activities. We propose a model for the generation of these genomic abnormalities which suggests a role for MGME1 outside of nascent mtDNA end ligation. Our results highlight the role of MGME1 in and outside of the D-loop region during replication, support the involvement of MGME1 in dsDNA degradation, and demonstrate that POLG EXO and MGME1 can partially compensate for each other in maintaining mtDNA.
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Affiliation(s)
- Christian D Gonzalez
- MSTP and MCDB Programs, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Nadee Nissanka
- Department of Neurology, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Derek Van Booven
- John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Anthony J Griswold
- John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Carlos T Moraes
- Department of Neurology, University of Miami Miller School of Medicine, Miami, Florida, USA.
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9
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Ali A, Esmaeil A, Behbehani R. Mitochondrial Chronic Progressive External Ophthalmoplegia. Brain Sci 2024; 14:135. [PMID: 38391710 PMCID: PMC10887352 DOI: 10.3390/brainsci14020135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2023] [Revised: 01/22/2024] [Accepted: 01/26/2024] [Indexed: 02/24/2024] Open
Abstract
BACKGROUND Chronic progressive external ophthalmoplegia (CPEO) is a rare disorder that can be at the forefront of several mitochondrial diseases. This review overviews mitochondrial CPEO encephalomyopathies to enhance accurate recognition and diagnosis for proper management. METHODS This study is conducted based on publications and guidelines obtained by selective review in PubMed. Randomized, double-blind, placebo-controlled trials, Cochrane reviews, and literature meta-analyses were particularly sought. DISCUSSION CPEO is a common presentation of mitochondrial encephalomyopathies, which can result from alterations in mitochondrial or nuclear DNA. Genetic sequencing is the gold standard for diagnosing mitochondrial encephalomyopathies, preceded by non-invasive tests such as fibroblast growth factor-21 and growth differentiation factor-15. More invasive options include a muscle biopsy, which can be carried out after uncertain diagnostic testing. No definitive treatment option is available for mitochondrial diseases, and management is mainly focused on lifestyle risk modification and supplementation to reduce mitochondrial load and symptomatic relief, such as ptosis repair in the case of CPEO. Nevertheless, various clinical trials and endeavors are still at large for achieving beneficial therapeutic outcomes for mitochondrial encephalomyopathies. KEY MESSAGES Understanding the varying presentations and genetic aspects of mitochondrial CPEO is crucial for accurate diagnosis and management.
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Affiliation(s)
- Ali Ali
- Neuro-Ophthalmology Unit, Ibn Sina Hospital, Al-Bahar Ophthalmology Center, Kuwait City 70035, Kuwait
| | - Ali Esmaeil
- Neuro-Ophthalmology Unit, Ibn Sina Hospital, Al-Bahar Ophthalmology Center, Kuwait City 70035, Kuwait
| | - Raed Behbehani
- Neuro-Ophthalmology Unit, Ibn Sina Hospital, Al-Bahar Ophthalmology Center, Kuwait City 70035, Kuwait
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10
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Shammas MK, Nie Y, Gilsrud A, Huang X, Narendra DP, Chinnery PF. CHCHD10 mutations induce tissue-specific mitochondrial DNA deletions with a distinct signature. Hum Mol Genet 2023; 33:91-101. [PMID: 37815936 PMCID: PMC10729859 DOI: 10.1093/hmg/ddad161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 09/11/2023] [Accepted: 09/19/2023] [Indexed: 10/12/2023] Open
Abstract
Mutations affecting the mitochondrial intermembrane space protein CHCHD10 cause human disease, but it is not known why different amino acid substitutions cause markedly different clinical phenotypes, including amyotrophic lateral sclerosis-frontotemporal dementia, spinal muscular atrophy Jokela-type, isolated autosomal dominant mitochondrial myopathy and cardiomyopathy. CHCHD10 mutations have been associated with deletions of mitochondrial DNA (mtDNA deletions), raising the possibility that these explain the clinical variability. Here, we sequenced mtDNA obtained from hearts, skeletal muscle, livers and spinal cords of WT and Chchd10 G58R or S59L knockin mice to characterise the mtDNA deletion signatures of the two mutant lines. We found that the deletion levels were higher in G58R and S59L mice than in WT mice in some tissues depending on the Chchd10 genotype, and the deletion burden increased with age. Furthermore, we observed that the spinal cord was less prone to the development of mtDNA deletions than the other tissues examined. Finally, in addition to accelerating the rate of naturally occurring deletions, Chchd10 mutations also led to the accumulation of a novel set of deletions characterised by shorter direct repeats flanking the deletion breakpoints. Our results indicate that Chchd10 mutations in mice induce tissue-specific deletions which may also contribute to the clinical phenotype associated with these mutations in humans.
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Affiliation(s)
- Mario K Shammas
- Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus, Cambridge CB2 0QQ, United Kingdom
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, United Kingdom
- Inherited Movement Disorders Unit, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, 35 Convent Drive, Bethesda, MD 20892, United States
| | - Yu Nie
- Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus, Cambridge CB2 0QQ, United Kingdom
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, United Kingdom
| | - Alexandra Gilsrud
- Inherited Movement Disorders Unit, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, 35 Convent Drive, Bethesda, MD 20892, United States
| | - Xiaoping Huang
- Inherited Movement Disorders Unit, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, 35 Convent Drive, Bethesda, MD 20892, United States
| | - Derek P Narendra
- Inherited Movement Disorders Unit, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, 35 Convent Drive, Bethesda, MD 20892, United States
| | - Patrick F Chinnery
- Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus, Cambridge CB2 0QQ, United Kingdom
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, United Kingdom
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11
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Wojtaszek JL, Hoff KE, Longley MJ, Kaur P, Andres S, Wang H, Williams R, Copeland W. Structure-specific roles for PolG2-DNA complexes in maintenance and replication of mitochondrial DNA. Nucleic Acids Res 2023; 51:9716-9732. [PMID: 37592734 PMCID: PMC10570022 DOI: 10.1093/nar/gkad679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 07/13/2023] [Accepted: 08/09/2023] [Indexed: 08/19/2023] Open
Abstract
The homodimeric PolG2 accessory subunit of the mitochondrial DNA polymerase gamma (Pol γ) enhances DNA binding and processive DNA synthesis by the PolG catalytic subunit. PolG2 also directly binds DNA, although the underlying molecular basis and functional significance are unknown. Here, data from Atomic Force Microscopy (AFM) and X-ray structures of PolG2-DNA complexes define dimeric and hexameric PolG2 DNA binding modes. Targeted disruption of PolG2 DNA-binding interfaces impairs processive DNA synthesis without diminishing Pol γ subunit affinities. In addition, a structure-specific DNA-binding role for PolG2 oligomers is supported by X-ray structures and AFM showing that oligomeric PolG2 localizes to DNA crossings and targets forked DNA structures resembling the mitochondrial D-loop. Overall, data indicate that PolG2 DNA binding has both PolG-dependent and -independent functions in mitochondrial DNA replication and maintenance, which provide new insight into molecular defects associated with PolG2 disruption in mitochondrial disease.
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Affiliation(s)
- Jessica L Wojtaszek
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Kirsten E Hoff
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Matthew J Longley
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Parminder Kaur
- Physics Department, North Carolina State University, Raleigh, NC 27695, USA
- Center for Human Health and the Environment, North Carolina State University, Raleigh, NC 27695, USA
| | - Sara N Andres
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Hong Wang
- Physics Department, North Carolina State University, Raleigh, NC 27695, USA
- Center for Human Health and the Environment, North Carolina State University, Raleigh, NC 27695, USA
- Toxicology Program, North Carolina State University, Raleigh, NC 27695, USA
| | - R Scott Williams
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - William C Copeland
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
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12
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Kroneisl M, Spraakman NA, Koomen JV, Hijazi Z, Hoogstra-Berends FH, Leuvenink HGD, Struys MMRF, Henning RH, Nieuwenhuijs-Moeke GJ. Peri-Operative Kinetics of Plasma Mitochondrial DNA Levels during Living Donor Kidney Transplantation. Int J Mol Sci 2023; 24:13579. [PMID: 37686384 PMCID: PMC10487554 DOI: 10.3390/ijms241713579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 08/27/2023] [Accepted: 08/28/2023] [Indexed: 09/10/2023] Open
Abstract
During ischemia and reperfusion injury (IRI), mitochondria may release mitochondrial DNA (mtDNA). mtDNA can serve as a propagator of further injury but in specific settings has anti-inflammatory capacities as well. Therefore, the aim of this study was to study the perioperative dynamics of plasma mtDNA during living donor kidney transplantation (LDKT) and its potential as a marker of graft outcome. Fifty-six donor-recipient couples from the Volatile Anesthetic Protection of Renal Transplants-1 (VAPOR-1) trial were included. Systemic venous, systemic arterial, and renal venous samples were taken at multiple timepoints during and after LDKT. Levels of mtDNA genes changed over time and between vascular compartments. Several donor, recipient, and transplantation-related variables significantly explained the course of mtDNA genes over time. mtDNA genes predicted 1-month and 24-month estimated glomerular filtration rate (eGFR) and acute rejection episodes in the two-year follow-up period. To conclude, mtDNA is released in plasma during the process of LDKT, either from the kidney or from the whole body in response to transplantation. While circulating mtDNA levels positively and negatively predict post-transplantation outcomes, the exact mechanisms and difference between mtDNA genes are not yet understood and need further exploration.
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Affiliation(s)
- Marie Kroneisl
- Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands
| | - Nora A. Spraakman
- Department of Anesthesiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands
| | - Jeroen V. Koomen
- Department of Anesthesiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands
| | - Zeinab Hijazi
- Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands
| | - Femke H. Hoogstra-Berends
- Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands
| | - Henri G. D. Leuvenink
- Department of Surgery, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands
| | - Michel M. R. F. Struys
- Department of Anesthesiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands
- Department of Basic and Applied Medical Sciences, Ghent University, 9000 Ghent, Belgium
| | - Rob H. Henning
- Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands
| | - Gertrude J. Nieuwenhuijs-Moeke
- Department of Anesthesiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands
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13
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Liu C, Zhang N, Xu Z, Wang X, Yang Y, Bu J, Cao H, Xiao J, Xie Y. Nuclear mitochondria-related genes-based molecular classification and prognostic signature reveal immune landscape, somatic mutation, and prognosis for glioma. Heliyon 2023; 9:e19856. [PMID: 37809472 PMCID: PMC10559255 DOI: 10.1016/j.heliyon.2023.e19856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 08/22/2023] [Accepted: 09/04/2023] [Indexed: 10/10/2023] Open
Abstract
Background Glioma is the most frequent malignant primary brain tumor, and mitochondria may influence the progression of glioma. The aim of this study was to analyze the role of nuclear mitochondria related genes (MTRGs) in glioma, identify subtypes and construct a prognostic model based on nuclear MTRGs and machine learning algorithms. Methods Samples containing both gene expression profiles and clinical information were retrieved from the TCGA database, CGGA database, and GEO database. We selected 16 nuclear MTRGs and identified two clusters of glioma. Prognostic features, microenvironment, mutation landscape, and drug sensitivity were compared between the clusters. A prognostic model based on multiple machine learning algorithms was then constructed and validated by multiple datasets. Results We observed significant discrepancies between the two clusters. Cluster One had higher nuclear MTRG expression, a lower survival rate, and higher immune infiltration than Cluster Two. For the two clusters, we found distinct predictive drug sensitivities and responses to immune therapy, and the infiltration of immune cells was significantly different. Among the 22 combinations of machine learning algorithms we tested, LASSO was the most effective in constructing the prognostic model. The model's accuracy was further verified in three independent glioma datasets. We identified MGME1 as a vital gene associated with infiltrating immune cells in multiple types of tumors. Conclusion In short, our research identified two clusters of glioma and developed a dependable prognostic model based on machine learning methods. MGME1 was identified as a potential biomarker for multiple tumors. Our results will contribute to precise medicine and glioma management.
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Affiliation(s)
- Chang Liu
- College of Life Sciences, Anhui Medical University, Hefei, 230032, Anhui, China
- School of Basic Medical Sciences, Anhui Medical University, Hefei, 230032, Anhui, China
- Second School of Clinical Medicine, Anhui Medical University, Hefei, 230032, Anhui, China
| | - Ning Zhang
- School of Basic Medical Sciences, Anhui Medical University, Hefei, 230032, Anhui, China
- First School of Clinical Medicine, Anhui Medical University, Hefei, 230032, Anhui, China
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, 230022, Anhui, China
| | - Zhihao Xu
- School of Basic Medical Sciences, Anhui Medical University, Hefei, 230032, Anhui, China
- First School of Clinical Medicine, Anhui Medical University, Hefei, 230032, Anhui, China
- Department of Neurosurgery, First Affiliated Hospital of Anhui Medical University, Hefei, 230022, Anhui, China
| | - Xiaofeng Wang
- School of Basic Medical Sciences, Anhui Medical University, Hefei, 230032, Anhui, China
| | - Yang Yang
- School of Basic Medical Sciences, Anhui Medical University, Hefei, 230032, Anhui, China
- First School of Clinical Medicine, Anhui Medical University, Hefei, 230032, Anhui, China
| | - Junming Bu
- School of Basic Medical Sciences, Anhui Medical University, Hefei, 230032, Anhui, China
- Second School of Clinical Medicine, Anhui Medical University, Hefei, 230032, Anhui, China
| | - Huake Cao
- School of Basic Medical Sciences, Anhui Medical University, Hefei, 230032, Anhui, China
- First School of Clinical Medicine, Anhui Medical University, Hefei, 230032, Anhui, China
| | - Jin Xiao
- Department of Neurosurgery, First Affiliated Hospital of Anhui Medical University, Hefei, 230022, Anhui, China
| | - Yinyin Xie
- College of Life Sciences, Anhui Medical University, Hefei, 230032, Anhui, China
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14
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Caston RA, Fortini P, Chen K, Bauer J, Dogliotti E, Yin YW, Demple B. Maintenance of Flap Endonucleases for Long-Patch Base Excision DNA Repair in Mouse Muscle and Neuronal Cells Differentiated In Vitro. Int J Mol Sci 2023; 24:12715. [PMID: 37628896 PMCID: PMC10454756 DOI: 10.3390/ijms241612715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 08/02/2023] [Accepted: 08/03/2023] [Indexed: 08/27/2023] Open
Abstract
After cellular differentiation, nuclear DNA is no longer replicated, and many of the associated proteins are downregulated accordingly. These include the structure-specific endonucleases Fen1 and DNA2, which are implicated in repairing mitochondrial DNA (mtDNA). Two more such endonucleases, named MGME1 and ExoG, have been discovered in mitochondria. This category of nuclease is required for so-called "long-patch" (multinucleotide) base excision DNA repair (BER), which is necessary to process certain oxidative lesions, prompting the question of how differentiation affects the availability and use of these enzymes in mitochondria. In this study, we demonstrate that Fen1 and DNA2 are indeed strongly downregulated after differentiation of neuronal precursors (Cath.a-differentiated cells) or mouse myotubes, while the expression levels of MGME1 and ExoG showed minimal changes. The total flap excision activity in mitochondrial extracts of these cells was moderately decreased upon differentiation, with MGME1 as the predominant flap endonuclease and ExoG playing a lesser role. Unexpectedly, both differentiated cell types appeared to accumulate less oxidative or alkylation damage in mtDNA than did their proliferating progenitors. Finally, the overall rate of mtDNA repair was not significantly different between proliferating and differentiated cells. Taken together, these results indicate that neuronal cells maintain mtDNA repair upon differentiation, evidently relying on mitochondria-specific enzymes for long-patch BER.
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Affiliation(s)
- Rachel A. Caston
- Department of Pharmacological Sciences, Renaissance School of Medicine, Stony Brook University, Stony Brook, NY 11794, USA
| | - Paola Fortini
- Department of Environment and Health, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy; (P.F.)
| | - Kevin Chen
- Department of Pharmacological Sciences, Renaissance School of Medicine, Stony Brook University, Stony Brook, NY 11794, USA
| | - Jack Bauer
- Department of Pharmacological Sciences, Renaissance School of Medicine, Stony Brook University, Stony Brook, NY 11794, USA
| | - Eugenia Dogliotti
- Department of Environment and Health, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy; (P.F.)
| | - Y. Whitney Yin
- Department of Pharmacology and Toxicology, Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Bruce Demple
- Department of Pharmacological Sciences, Renaissance School of Medicine, Stony Brook University, Stony Brook, NY 11794, USA
- Department of Radiation Oncology, Renaissance School of Medicine, Stony Brook University, Stony Brook, NY 11794, USA
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15
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da Silva Rocha EB, de Lima Rodrigues K, Montouro LAM, Coelho ÉN, Kouyoumdjian JA, Kok F, Nóbrega PR, Graca CR, Morita MDPA, Estephan EDP. A case of mitochondrial DNA depletion syndrome type 11 - expanding the genotype and phenotype. Neuromuscul Disord 2023; 33:692-696. [PMID: 37429773 DOI: 10.1016/j.nmd.2023.06.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 05/26/2023] [Accepted: 06/13/2023] [Indexed: 07/12/2023]
Abstract
Mitochondrial DNA depletion syndrome type 11 (MTDPS11) is caused by pathogenic variants in MGME1 gene. We report a woman, 40-year-old, who presented slow progressive drop eyelid at 11-year-old with, learning difficulty and frequent falls. Phisical examination revealed: mild scoliosis, elbow hyperextensibility, flat feet, chronic progressive external ophthalmoplegia with upper eyelid ptosis, diffuse hypotonia, and weakness of arm abduction and neck flexion. Investigation evidenced mild serum creatine kinase increase and glucose intolerance; second-degree atrioventricular block; mild mixed-type respiratory disorder and atrophy and granular appearance of the retinal pigment epithelium. Brain magnetic resonance showed cerebellar atrophy. Muscle biopsy was compatible with mitochondrial myopathy. Genetic panel revealed a homozygous pathogenic variant in the MGME1 gene, consistent with MTDPS11 (c.862C>T; p.Gln288*). This case of MTDPS11 can contribute to the phenotypic characterization of this ultra-rare mitochondrial disorder, presenting milder respiratory and nutritional involvement than the previously reported cases, with possible additional features.
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Affiliation(s)
- Emanuelle Bianchi da Silva Rocha
- Department of Neurological Sciences, Psychiatry and Medical Psychology, Faculdade Estadual de Medicina de São José do Rio Preto (FAMERP), Brigadeiro Faria Lima Avenue, 5416, 15090-000 São José do Rio Preto, São Paulo, Brazil
| | - Ketteny de Lima Rodrigues
- Department of Neurological Sciences, Psychiatry and Medical Psychology, Faculdade Estadual de Medicina de São José do Rio Preto (FAMERP), Brigadeiro Faria Lima Avenue, 5416, 15090-000 São José do Rio Preto, São Paulo, Brazil
| | - Laura Alonso Matheus Montouro
- Department of Neurological Sciences, Psychiatry and Medical Psychology, Faculdade Estadual de Medicina de São José do Rio Preto (FAMERP), Brigadeiro Faria Lima Avenue, 5416, 15090-000 São José do Rio Preto, São Paulo, Brazil
| | - Érica Nogueira Coelho
- Department of Neurological Sciences, Psychiatry and Medical Psychology, Fundação Faculdade Regional de Medicina São José do Rio Preto (FUNFARME), Brigadeiro Faria Lima Avenue, 5416, 15090-000 São José do Rio Preto, São Paulo, Brazil
| | - João Aris Kouyoumdjian
- Department of Neurological Sciences, Psychiatry and Medical Psychology, Faculdade Estadual de Medicina de São José do Rio Preto (FAMERP), Brigadeiro Faria Lima Avenue, 5416, 15090-000 São José do Rio Preto, São Paulo, Brazil
| | - Fernando Kok
- Department of Neurology, Faculdade de Medicina da Universidade de São Paulo (FMUSP), Ovídio Pires de Campos Street, 225, 05403-010 São Paulo, Brazil
| | - Paulo Ribeiro Nóbrega
- Department of Neurology, Faculdade de Medicina da Universidade Federal do Ceará (UFC), Alexandre Baraúna, 949, 60430-160 Fortaleza, Ceará, Brazil
| | - Carla Renata Graca
- Department of Neurological Sciences, Psychiatry and Medical Psychology, Faculdade Estadual de Medicina de São José do Rio Preto (FAMERP), Brigadeiro Faria Lima Avenue, 5416, 15090-000 São José do Rio Preto, São Paulo, Brazil
| | - Maria da Penha Ananias Morita
- Department of Neurological Sciences, Psychiatry and Medical Psychology, Faculdade Estadual de Medicina de São José do Rio Preto (FAMERP), Brigadeiro Faria Lima Avenue, 5416, 15090-000 São José do Rio Preto, São Paulo, Brazil
| | - Eduardo de Paula Estephan
- Department of Neurological Sciences, Psychiatry and Medical Psychology, Fundação Faculdade Regional de Medicina São José do Rio Preto (FUNFARME), Brigadeiro Faria Lima Avenue, 5416, 15090-000 São José do Rio Preto, São Paulo, Brazil; Department of Neurology, Faculdade de Medicina da Universidade de São Paulo (FMUSP), Ovídio Pires de Campos Street, 225, 05403-010 São Paulo, Brazil; Hospital Santa Marcelina, Department of Neurology, São Paulo, Brazil; Faculdade de Medicina Santa Marcelina (FASM), Department of Medical Clinic, São Paulo, Brazil.
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16
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Potter A, Hangas A, Goffart S, Huynen MA, Cabrera-Orefice A, Spelbrink JN. Uncharacterized protein C17orf80 - a novel interactor of human mitochondrial nucleoids. J Cell Sci 2023; 136:jcs260822. [PMID: 37401363 PMCID: PMC10445727 DOI: 10.1242/jcs.260822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 06/26/2023] [Indexed: 07/05/2023] Open
Abstract
Molecular functions of many human proteins remain unstudied, despite the demonstrated association with diseases or pivotal molecular structures, such as mitochondrial DNA (mtDNA). This small genome is crucial for the proper functioning of mitochondria, the energy-converting organelles. In mammals, mtDNA is arranged into macromolecular complexes called nucleoids that serve as functional stations for its maintenance and expression. Here, we aimed to explore an uncharacterized protein C17orf80, which was previously detected close to the nucleoid components by proximity labelling mass spectrometry. To investigate the subcellular localization and function of C17orf80, we took advantage of immunofluorescence microscopy, interaction proteomics and several biochemical assays. We demonstrate that C17orf80 is a mitochondrial membrane-associated protein that interacts with nucleoids even when mtDNA replication is inhibited. In addition, we show that C17orf80 is not essential for mtDNA maintenance and mitochondrial gene expression in cultured human cells. These results provide a basis for uncovering the molecular function of C17orf80 and the nature of its association with nucleoids, possibly leading to new insights about mtDNA and its expression.
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Affiliation(s)
- Alisa Potter
- Department of Pediatrics, Amalia Children's Hospital, Radboud University Medical Center, Nijmegen, 6525 GA, The Netherlands
- Radboud Center for Mitochondrial Medicine (RCMM), Radboud University Medical Center, Nijmegen, 6525 GA, The Netherlands
| | - Anu Hangas
- Department of Environmental and Biological Sciences, University of Eastern Finland, Joensuu, 80101, Finland
| | - Steffi Goffart
- Department of Environmental and Biological Sciences, University of Eastern Finland, Joensuu, 80101, Finland
| | - Martijn A. Huynen
- Department of Medical BioSciences, Radboud University Medical Center, Nijmegen, 6525 GA, The Netherlands
| | - Alfredo Cabrera-Orefice
- Radboud Center for Mitochondrial Medicine (RCMM), Radboud University Medical Center, Nijmegen, 6525 GA, The Netherlands
- Department of Medical BioSciences, Radboud University Medical Center, Nijmegen, 6525 GA, The Netherlands
| | - Johannes N. Spelbrink
- Department of Pediatrics, Amalia Children's Hospital, Radboud University Medical Center, Nijmegen, 6525 GA, The Netherlands
- Radboud Center for Mitochondrial Medicine (RCMM), Radboud University Medical Center, Nijmegen, 6525 GA, The Netherlands
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17
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Saiki R, Katayama K, Dohi K. Recent Advances in Proteinuric Kidney Disease/Nephrotic Syndrome: Lessons from Knockout/Transgenic Mouse Models. Biomedicines 2023; 11:1803. [PMID: 37509442 PMCID: PMC10376620 DOI: 10.3390/biomedicines11071803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 06/21/2023] [Accepted: 06/21/2023] [Indexed: 07/30/2023] Open
Abstract
Proteinuria is known to be associated with all-cause and cardiovascular mortality, and nephrotic syndrome is defined by the level of proteinuria and hypoalbuminemia. With advances in medicine, new causative genes for genetic kidney diseases are being discovered increasingly frequently. We reviewed articles on proteinuria/nephrotic syndrome, focal segmental glomerulosclerosis, membranous nephropathy, diabetic kidney disease/nephropathy, hypertension/nephrosclerosis, Alport syndrome, and rare diseases, which have been studied in mouse models. Significant progress has been made in understanding the genetics and pathophysiology of kidney diseases thanks to advances in science, but research in this area is ongoing. In the future, genetic analyses of patients with proteinuric kidney disease/nephrotic syndrome may ultimately lead to personalized treatment options.
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Affiliation(s)
- Ryosuke Saiki
- Department of Cardiology and Nephrology, Mie University Graduate School of Medicine, Tsu 514-8507, Japan
| | - Kan Katayama
- Department of Cardiology and Nephrology, Mie University Graduate School of Medicine, Tsu 514-8507, Japan
| | - Kaoru Dohi
- Department of Cardiology and Nephrology, Mie University Graduate School of Medicine, Tsu 514-8507, Japan
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18
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Erdinc D, Rodríguez‐Luis A, Fassad MR, Mackenzie S, Watson CM, Valenzuela S, Xie X, Menger KE, Sergeant K, Craig K, Hopton S, Falkous G, Poulton J, Garcia‐Moreno H, Giunti P, de Moura Aschoff CA, Morales Saute JA, Kirby AJ, Toro C, Wolfe L, Novacic D, Greenbaum L, Eliyahu A, Barel O, Anikster Y, McFarland R, Gorman GS, Schaefer AM, Gustafsson CM, Taylor RW, Falkenberg M, Nicholls TJ. Pathological variants in TOP3A cause distinct disorders of mitochondrial and nuclear genome stability. EMBO Mol Med 2023; 15:e16775. [PMID: 37013609 PMCID: PMC10165364 DOI: 10.15252/emmm.202216775] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 03/10/2023] [Accepted: 03/14/2023] [Indexed: 04/05/2023] Open
Abstract
Topoisomerase 3α (TOP3A) is an enzyme that removes torsional strain and interlinks between DNA molecules. TOP3A localises to both the nucleus and mitochondria, with the two isoforms playing specialised roles in DNA recombination and replication respectively. Pathogenic variants in TOP3A can cause a disorder similar to Bloom syndrome, which results from bi-allelic pathogenic variants in BLM, encoding a nuclear-binding partner of TOP3A. In this work, we describe 11 individuals from 9 families with an adult-onset mitochondrial disease resulting from bi-allelic TOP3A gene variants. The majority of patients have a consistent clinical phenotype characterised by bilateral ptosis, ophthalmoplegia, myopathy and axonal sensory-motor neuropathy. We present a comprehensive characterisation of the effect of TOP3A variants, from individuals with mitochondrial disease and Bloom-like syndrome, upon mtDNA maintenance and different aspects of enzyme function. Based on these results, we suggest a model whereby the overall severity of the TOP3A catalytic defect determines the clinical outcome, with milder variants causing adult-onset mitochondrial disease and more severe variants causing a Bloom-like syndrome with mitochondrial dysfunction in childhood.
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Affiliation(s)
- Direnis Erdinc
- Department of Medical Biochemistry and Cell BiologyUniversity of GothenburgGothenburgSweden
| | - Alejandro Rodríguez‐Luis
- Wellcome Centre for Mitochondrial Research, Faculty of Medical SciencesNewcastle UniversityNewcastle upon TyneUK
- Biosciences Institute, Faculty of Medical SciencesNewcastle UniversityNewcastle upon TyneUK
| | - Mahmoud R Fassad
- Wellcome Centre for Mitochondrial Research, Faculty of Medical SciencesNewcastle UniversityNewcastle upon TyneUK
- Translational and Clinical Research Institute, Faculty of Medical SciencesNewcastle UniversityNewcastle upon TyneUK
| | - Sarah Mackenzie
- The Newcastle Upon Tyne Hospitals NHS Foundation TrustNewcastle upon TyneUK
| | - Christopher M Watson
- North East and Yorkshire Genomic Laboratory Hub, Central LabSt. James's University HospitalLeedsUK
- Leeds Institute of Medical ResearchUniversity of Leeds, St. James's University HospitalLeedsUK
| | - Sebastian Valenzuela
- Department of Medical Biochemistry and Cell BiologyUniversity of GothenburgGothenburgSweden
| | - Xie Xie
- Department of Medical Biochemistry and Cell BiologyUniversity of GothenburgGothenburgSweden
| | - Katja E Menger
- Wellcome Centre for Mitochondrial Research, Faculty of Medical SciencesNewcastle UniversityNewcastle upon TyneUK
- Biosciences Institute, Faculty of Medical SciencesNewcastle UniversityNewcastle upon TyneUK
| | - Kate Sergeant
- Oxford Genetics LaboratoriesOxford University Hospitals NHS Foundation TrustOxfordUK
| | - Kate Craig
- Wellcome Centre for Mitochondrial Research, Faculty of Medical SciencesNewcastle UniversityNewcastle upon TyneUK
- NHS Highly Specialised Service for Rare Mitochondrial DisordersNewcastle upon Tyne Hospitals NHS Foundation TrustNewcastle upon TyneUK
| | - Sila Hopton
- Wellcome Centre for Mitochondrial Research, Faculty of Medical SciencesNewcastle UniversityNewcastle upon TyneUK
- NHS Highly Specialised Service for Rare Mitochondrial DisordersNewcastle upon Tyne Hospitals NHS Foundation TrustNewcastle upon TyneUK
| | - Gavin Falkous
- Wellcome Centre for Mitochondrial Research, Faculty of Medical SciencesNewcastle UniversityNewcastle upon TyneUK
- NHS Highly Specialised Service for Rare Mitochondrial DisordersNewcastle upon Tyne Hospitals NHS Foundation TrustNewcastle upon TyneUK
| | | | - Joanna Poulton
- Nuffield Department of Women's & Reproductive Health, The Women's CentreUniversity of OxfordOxfordUK
| | - Hector Garcia‐Moreno
- Department of Clinical and Movement Neurosciences, Ataxia CentreUCL Queen Square Institute of NeurologyLondonUK
| | - Paola Giunti
- Department of Clinical and Movement Neurosciences, Ataxia CentreUCL Queen Square Institute of NeurologyLondonUK
| | | | - Jonas A Morales Saute
- Medical Genetics ServiceHospital de Clínicas de Porto Alegre (HCPA)Porto AlegreBrazil
- Department of Internal MedicineUniversidade Federal do Rio Grande do SulPorto AlegreBrazil
- Graduate Program in Medicine: Medical SciencesUniversidade Federal do Rio Grande do SulPorto AlegreBrazil
| | - Amelia J Kirby
- Department of PediatricsWake Forest School of MedicineWinston‐SalemNCUSA
| | - Camilo Toro
- Undiagnosed Diseases ProgramNational Human Genome Research Institute, National Institutes of HealthBethesdaMDUSA
| | - Lynne Wolfe
- Undiagnosed Diseases ProgramNational Human Genome Research Institute, National Institutes of HealthBethesdaMDUSA
| | - Danica Novacic
- Undiagnosed Diseases ProgramNational Human Genome Research Institute, National Institutes of HealthBethesdaMDUSA
| | - Lior Greenbaum
- The Danek Gertner Institute of Human GeneticsSheba Medical CenterTel HashomerIsrael
- The Joseph Sagol Neuroscience Center, Sheba Medical CenterTel HashomerIsrael
- Sackler Faculty of MedicineTel Aviv UniversityTel AvivIsrael
| | - Aviva Eliyahu
- The Danek Gertner Institute of Human GeneticsSheba Medical CenterTel HashomerIsrael
- Sackler Faculty of MedicineTel Aviv UniversityTel AvivIsrael
| | - Ortal Barel
- Genomics UnitThe Center for Cancer Research, Sheba Medical CenterTel HashomerIsrael
| | - Yair Anikster
- Sackler Faculty of MedicineTel Aviv UniversityTel AvivIsrael
- Metabolic Disease UnitEdmond and Lily Safra Children's Hospital, Sheba Medical CenterTel HashomerIsrael
| | - Robert McFarland
- Wellcome Centre for Mitochondrial Research, Faculty of Medical SciencesNewcastle UniversityNewcastle upon TyneUK
- Translational and Clinical Research Institute, Faculty of Medical SciencesNewcastle UniversityNewcastle upon TyneUK
| | - Gráinne S Gorman
- Wellcome Centre for Mitochondrial Research, Faculty of Medical SciencesNewcastle UniversityNewcastle upon TyneUK
- Translational and Clinical Research Institute, Faculty of Medical SciencesNewcastle UniversityNewcastle upon TyneUK
| | - Andrew M Schaefer
- Wellcome Centre for Mitochondrial Research, Faculty of Medical SciencesNewcastle UniversityNewcastle upon TyneUK
- NHS Highly Specialised Service for Rare Mitochondrial DisordersNewcastle upon Tyne Hospitals NHS Foundation TrustNewcastle upon TyneUK
| | - Claes M Gustafsson
- Department of Medical Biochemistry and Cell BiologyUniversity of GothenburgGothenburgSweden
- Department of Clinical ChemistrySahlgrenska University HospitalGothenburgSweden
| | - Robert W Taylor
- Wellcome Centre for Mitochondrial Research, Faculty of Medical SciencesNewcastle UniversityNewcastle upon TyneUK
- Translational and Clinical Research Institute, Faculty of Medical SciencesNewcastle UniversityNewcastle upon TyneUK
- NHS Highly Specialised Service for Rare Mitochondrial DisordersNewcastle upon Tyne Hospitals NHS Foundation TrustNewcastle upon TyneUK
| | - Maria Falkenberg
- Department of Medical Biochemistry and Cell BiologyUniversity of GothenburgGothenburgSweden
| | - Thomas J Nicholls
- Wellcome Centre for Mitochondrial Research, Faculty of Medical SciencesNewcastle UniversityNewcastle upon TyneUK
- Biosciences Institute, Faculty of Medical SciencesNewcastle UniversityNewcastle upon TyneUK
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19
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Functional Assessment of Mitochondrial DNA Maintenance by Depletion and Repopulation Using 2',3'-Dideoxycytidine in Cultured Cells. Methods Mol Biol 2023; 2615:229-240. [PMID: 36807796 DOI: 10.1007/978-1-0716-2922-2_17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
The manipulation of mitochondrial DNA (mtDNA) copy number in cultured cells, using substances that interfere with DNA replication, is a useful tool to investigate various aspects of mtDNA maintenance. Here we describe the use of 2',3'-dideoxycytidine (ddC) to induce a reversible reduction of mtDNA copy number in human primary fibroblasts and human embryonic kidney (HEK293) cells. Once the application of ddC is stopped, cells depleted for mtDNA attempt to recover normal mtDNA copy numbers. The dynamics of repopulation of mtDNA provide a valuable measure for the enzymatic activity of the mtDNA replication machinery.
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20
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Isolating Mitochondria, Mitoplasts, and mtDNA from Cultured Mammalian Cells. Methods Mol Biol 2023; 2615:17-30. [PMID: 36807781 DOI: 10.1007/978-1-0716-2922-2_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
Mitochondria are double membrane-bound eukaryotic organelles with roles in a range of cellular activities including energy conversion, apoptosis, cell signalling, and the biosynthesis of enzyme cofactors. Mitochondria contain their own genome, called mtDNA, which encodes subunits of the oxidative phosphorylation machinery as well as the rRNA and tRNA molecules required for their translation within mitochondria. The ability to isolate highly purified mitochondria from cells has been instrumental in a number of studies of mitochondrial function. Differential centrifugation is a long-established method for the isolation of mitochondria. Cells are subjected to osmotic swelling and disruption, followed by centrifugation in isotonic sucrose solutions to separate mitochondria from other cellular components. We present a method using this principle for the isolation of mitochondria from cultured mammalian cell lines. Mitochondria purified by this method can be further fractionated to investigate protein localization, or act as a starting point to purify mtDNA.
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21
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Pillalamarri V, Shi W, Say C, Yang S, Lane J, Guallar E, Pankratz N, Arking DE. Whole-exome sequencing in 415,422 individuals identifies rare variants associated with mitochondrial DNA copy number. HGG ADVANCES 2023; 4:100147. [PMID: 36311265 PMCID: PMC9615038 DOI: 10.1016/j.xhgg.2022.100147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 09/23/2022] [Indexed: 10/14/2022] Open
Abstract
Inter-individual variation in the number of copies of the mitochondrial genome, called mitochondrial DNA copy number (mtDNA-CN), reflects mitochondrial function and has been associated with various aging-related diseases. We examined 415,422 exomes of self-reported White ancestry individuals from the UK Biobank and tested the impact of rare variants, at the level of single variants and through aggregate variant-set tests, on mtDNA-CN. A survey across nine variant sets tested enrichment of putatively causal variants and identified 14 genes at experiment-wide significance and three genes at marginal significance. These included associations at known mtDNA depletion syndrome genes (mtDNA helicase TWNK, p = 1.1 × 10-30; mitochondrial transcription factor TFAM, p = 4.3 × 10-15; mtDNA maintenance exonuclease MGME1, p = 2.0 × 10-6) and the V617F dominant gain-of-function mutation in the tyrosine kinase JAK2 (p = 2.7 × 10-17), associated with myeloproliferative disease. Novel genes included the ATP-dependent protease CLPX (p = 8.4 × 10-9), involved in mitochondrial proteome quality, and the mitochondrial adenylate kinase AK2 (p = 4.7 × 10-8), involved in hematopoiesis. The most significant association was a missense variant in SAMHD1 (p = 4.2 × 10-28), found on a rare, 1.2-Mb shared ancestral haplotype on chromosome 20. SAMHD1 encodes a cytoplasmic host restriction factor involved in viral defense response and the mitochondrial nucleotide salvage pathway, and is associated with Aicardi-Goutières syndrome 5, a childhood encephalopathy and chronic inflammatory response disorder. Rare variants were enriched in Mendelian mtDNA depletion syndrome loci, and these variants implicated core processes in mtDNA replication, nucleoid structure formation, and maintenance. These data indicate that strong-effect mutations from the nuclear genome contribute to the genetic architecture of mtDNA-CN.
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Affiliation(s)
- Vamsee Pillalamarri
- McKusick-Nathans Institute, Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Predoctoral Program in Human Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Maryland Genetics Epidemiology and Medicine Training Program, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Wen Shi
- McKusick-Nathans Institute, Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Conrad Say
- McKusick-Nathans Institute, Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Stephanie Yang
- McKusick-Nathans Institute, Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Vertex Pharmaceuticals, Inc., Boston, MA 02210, USA
| | - John Lane
- Department of Laboratory Medicine and Pathology, University of Minnesota Medical School, Minneapolis, MN 55455, USA
| | - Eliseo Guallar
- Departments of Epidemiology and Medicine and Welch Center for Prevention, Epidemiology and Clinical Research, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Nathan Pankratz
- Department of Laboratory Medicine and Pathology, University of Minnesota Medical School, Minneapolis, MN 55455, USA
| | - Dan E. Arking
- McKusick-Nathans Institute, Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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22
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Abstract
Progressive external ophthalmoplegia (PEO), characterized by ptosis and impaired eye movements, is a clinical syndrome with an expanding number of etiologically distinct subtypes. Advances in molecular genetics have revealed numerous pathogenic causes of PEO, originally heralded in 1988 by the detection of single large-scale deletions of mitochondrial DNA (mtDNA) in skeletal muscle of people with PEO and Kearns-Sayre syndrome. Since then, multiple point variants of mtDNA and nuclear genes have been identified to cause mitochondrial PEO and PEO-plus syndromes, including mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) and sensory ataxic neuropathy dysarthria ophthalmoplegia (SANDO). Intriguingly, many of those nuclear DNA pathogenic variants impair maintenance of the mitochondrial genome causing downstream mtDNA multiple deletions and depletion. In addition, numerous genetic causes of nonmitochondrial PEO have been identified.
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Affiliation(s)
- Michio Hirano
- H. Houston Merritt Neuromuscular Research Center, Neuromuscular Medicine Division, Department of Neurology, Columbia University Irving Medical Center, New York, NY, United States.
| | - Robert D S Pitceathly
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, United Kingdom; NHS Highly Specialised Service for Rare Mitochondrial Disorders, Queen Square Centre for Neuromuscular Diseases, National Hospital for Neurology and Neurosurgery, London, United Kingdom
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23
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Yalçınkaya B, Tastekin D, Güzelbulut F, Akgoz M, Pençe S. Quantification of cell-free circulating mitochondrial DNA copy number variation in hepatocellular carcinoma. Rev Assoc Med Bras (1992) 2022; 68:1161-1165. [PMID: 36228247 PMCID: PMC9575012 DOI: 10.1590/1806-9282.20210368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Accepted: 05/16/2022] [Indexed: 11/07/2022] Open
Abstract
OBJECTIVE Hepatocellular carcinoma is the most common primary malignant liver tumor. Mitochondrial DNA copy number has been shown to be associated with various malignancies. However, there has not been any study on the absolute quantification of mtDNA copy number in hepatocellular carcinoma. The aim of this study was to develop a new method for absolute quantification of mtDNA copy number and to relatively quantify the variations in the mtDNA copy number in hepatocellular carcinoma patients in comparison with healthy individuals. METHODS Venous blood samples were collected from both hepatocellular carcinoma patients (34) and healthy individuals (34). Circulating cell-free DNAs were isolated and the relative quantification of mtDNA copy number variation was determined using quantitative polymerase chain reaction and digital polymerase chain reaction. RESULTS It was found that the relative mtDNA copy number was significantly decreased in hepatocellular carcinoma patients in comparison with the control group (p<0.05). The median (range) and average of relative mtDNA/β-actin gene of the patients were determined as 42.8 cp/μL (11.1-88.5) and 45.1 cp/μL, respectively, while the median (range) and average relative mtDNA/β-actin gene of the control group were determined as 102.8 cp/μL (55.1-291.8) and 138.7 cp/μL, respectively (p<0.05). When quantitative polymerase chain reaction and digital polymerase chain reaction were compared, mtDNA/β-actin gene copy number ratio of digital polymerase chain reaction results was found to be 1.76-fold more than that of quantitative polymerase chain reaction results. CONCLUSION Circulating mtDNA copy number was decreased in hepatocellular carcinoma patients in comparison with healthy individuals, and we suggest that it can be used as a noninvasive biomarker for hepatocellular carcinoma diagnosis in the future.
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Affiliation(s)
| | - Didem Tastekin
- Istanbul University, Institute of Oncology – Istanbul, Turkey
| | - Fatih Güzelbulut
- University of Health Sciences, Haydarpaşa Numune Training and Research Hospital – Istanbul, Turkey
| | - Muslum Akgoz
- TUBITAK National Metrology Institute – Kocaeli, Turkey
| | - Sadrettin Pençe
- Istanbul Medeniyet University, Faculty of Medicine – Istanbul, Turkey
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24
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Misic J, Milenkovic D, Al-Behadili A, Xie X, Jiang M, Jiang S, Filograna R, Koolmeister C, Siira S, Jenninger L, Filipovska A, Clausen A, Caporali L, Valentino M, La Morgia C, Carelli V, Nicholls T, Wredenberg A, Falkenberg M, Larsson NG. Mammalian RNase H1 directs RNA primer formation for mtDNA replication initiation and is also necessary for mtDNA replication completion. Nucleic Acids Res 2022; 50:8749-8766. [PMID: 35947649 PMCID: PMC9410905 DOI: 10.1093/nar/gkac661] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 07/08/2022] [Accepted: 08/04/2022] [Indexed: 12/24/2022] Open
Abstract
The in vivo role for RNase H1 in mammalian mitochondria has been much debated. Loss of RNase H1 is embryonic lethal and to further study its role in mtDNA expression we characterized a conditional knockout of Rnaseh1 in mouse heart. We report that RNase H1 is essential for processing of RNA primers to allow site-specific initiation of mtDNA replication. Without RNase H1, the RNA:DNA hybrids at the replication origins are not processed and mtDNA replication is initiated at non-canonical sites and becomes impaired. Importantly, RNase H1 is also needed for replication completion and in its absence linear deleted mtDNA molecules extending between the two origins of mtDNA replication are formed accompanied by mtDNA depletion. The steady-state levels of mitochondrial transcripts follow the levels of mtDNA, and RNA processing is not altered in the absence of RNase H1. Finally, we report the first patient with a homozygous pathogenic mutation in the hybrid-binding domain of RNase H1 causing impaired mtDNA replication. In contrast to catalytically inactive variants of RNase H1, this mutant version has enhanced enzyme activity but shows impaired primer formation. This finding shows that the RNase H1 activity must be strictly controlled to allow proper regulation of mtDNA replication.
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Affiliation(s)
- Jelena Misic
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm 17177, Sweden
| | | | - Ali Al-Behadili
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, PO Box 440, Gothenburg 405 30, Sweden
| | - Xie Xie
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, PO Box 440, Gothenburg 405 30, Sweden
| | - Min Jiang
- Key Laboratory of Growth Regulation and Translational Research of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang 310024, China
| | - Shan Jiang
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm 17177, Sweden
| | - Roberta Filograna
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm 17177, Sweden
| | - Camilla Koolmeister
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm 17177, Sweden
| | - Stefan J Siira
- Harry Perkins Institute of Medical Research and ARC Centre of Excellence in Synthetic Biology, Nedlands, WA 6009, Australia
| | - Louise Jenninger
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, PO Box 440, Gothenburg 405 30, Sweden
| | - Aleksandra Filipovska
- Harry Perkins Institute of Medical Research and ARC Centre of Excellence in Synthetic Biology, Nedlands, WA 6009, Australia,Telethon Kids Institute, Northern Entrance, Perth Children's Hospital, 15 Hospital Avenue, Nedlands, WA, Australia
| | - Anders R Clausen
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, PO Box 440, Gothenburg 405 30, Sweden
| | - Leonardo Caporali
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Programma di Neurogenetica, Bologna, Italy
| | - Maria Lucia Valentino
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Programma di Neurogenetica, Bologna, Italy,Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
| | - Chiara La Morgia
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Programma di Neurogenetica, Bologna, Italy
| | - Valerio Carelli
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Programma di Neurogenetica, Bologna, Italy,Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
| | - Thomas J Nicholls
- Wellcome Centre for Mitochondrial Research, Biosciences Institute, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
| | - Anna Wredenberg
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm 17177, Sweden,Centre for Inherited Metabolic Diseases, Karolinska University Hospital, Stockholm, Sweden
| | - Maria Falkenberg
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, PO Box 440, Gothenburg 405 30, Sweden
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25
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Urrutia KM, Xu W, Zhao L. The 5′-phosphate enhances the DNA-binding and exonuclease activities of human mitochondrial genome maintenance nuclease 1 (MGME1). J Biol Chem 2022; 298:102306. [PMID: 35934053 PMCID: PMC9460513 DOI: 10.1016/j.jbc.2022.102306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 07/13/2022] [Accepted: 07/15/2022] [Indexed: 11/15/2022] Open
Abstract
In higher eukaryotes, mitochondria play multiple roles in energy production, signaling, and biosynthesis. Mitochondria possess multiple copies of mitochondrial DNA (mtDNA), which encodes 37 genes that are essential for mitochondrial and cellular function. When mtDNA is challenged by endogenous and exogenous factors, mtDNA undergoes repair, degradation, and compensatory synthesis. mtDNA degradation is an emerging pathway in mtDNA damage response and maintenance. A key factor involved is the human mitochondrial genome maintenance exonuclease 1 (MGME1). Despite previous biochemical and functional studies, controversies exist regarding the polarity of MGME1-mediated DNA cleavage. Also, how DNA sequence may affect the activities of MGME1 remains elusive. Such information is not only fundamental to the understanding of MGME1 but critical for deciphering the mechanism of mtDNA degradation. Herein, we use quantitative assays to examine the effects of substrate structure and sequence on the DNA-binding and enzymatic activities of MGME1. We demonstrate that MGME1 binds to and cleaves from the 5′-end of single-stranded DNA substrates, especially in the presence of 5′-phosphate, which plays an important role in DNA binding and optimal cleavage by MGME1. In addition, MGME1 tolerates certain modifications at the terminal end, such as a 5′-deoxyribosephosphate intermediate formed in base excision repair. We show that MGME1 processes different sequences with varying efficiencies, with dT and dC sequences being the most and least efficiently digested, respectively. Our results provide insights into the enzymatic properties of MGME1 and a rationale for the coordination of MGME1 with the 3′–5′ exonuclease activity of DNA polymerase γ in mtDNA degradation.
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Affiliation(s)
- Kathleen M Urrutia
- Department of Chemistry, University of California, Riverside, Riverside, California, USA
| | - Wenyan Xu
- Department of Chemistry, University of California, Riverside, Riverside, California, USA
| | - Linlin Zhao
- Department of Chemistry, University of California, Riverside, Riverside, California, USA; Environmental Toxicology Graduate Program, University of California, Riverside, Riverside, California, USA.
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26
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López-Gómez C, Cámara Y, Hirano M, Martí R. 232nd ENMC international workshop: Recommendations for treatment of mitochondrial DNA maintenance disorders. 16 - 18 June 2017, Heemskerk, The Netherlands. Neuromuscul Disord 2022; 32:609-620. [PMID: 35641351 DOI: 10.1016/j.nmd.2022.05.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 05/12/2022] [Indexed: 11/24/2022]
Affiliation(s)
| | - Yolanda Cámara
- Research Group on Neuromuscular and Mitochondrial Diseases, Vall d'Hebron Research Institute, Universitat Autònoma de Barcelona, Barcelona, Catalonia, Spain; Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | - Michio Hirano
- Columbia University Irving Medical Center, New York, USA
| | - Ramon Martí
- Research Group on Neuromuscular and Mitochondrial Diseases, Vall d'Hebron Research Institute, Universitat Autònoma de Barcelona, Barcelona, Catalonia, Spain; Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain.
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27
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Galeota-Sprung B, Fernandez A, Sniegowski P. Changes to the mtDNA copy number during yeast culture growth. ROYAL SOCIETY OPEN SCIENCE 2022; 9:211842. [PMID: 35814911 PMCID: PMC9257595 DOI: 10.1098/rsos.211842] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Accepted: 06/10/2022] [Indexed: 06/15/2023]
Abstract
We show that the mitochondrial DNA (mtDNA) copy number in growing cultures of the yeast Saccharomyces cerevisiae increases by a factor of up to 4, being lowest (approx. 10 per haploid genome) and stable during rapid fermentative growth, and highest at the end of the respiratory phase. When yeast are grown on glucose, the onset of the mtDNA copy number increase coincides with the early stages of the diauxic shift, and the increase continues through respiration. A lesser yet still substantial copy number increase occurs when yeast are grown on a nonfermentable carbon source, i.e. when there is no diauxic shift. The mtDNA copy number increase during and for some time after the diauxic shift is not driven by an increase in cell size. The copy number increase occurs in both haploid and diploid strains but is markedly attenuated in a diploid wild isolate that is a ready sporulator. Strain-to-strain differences in mtDNA copy number are least apparent in fermentation and most apparent in late respiration or stationary phase. While changes in mitochondrial morphology and function were previously known to accompany changes in physiological state, it had not been previously shown that the mtDNA copy number changes substantially over time in a clonal growing culture. The mtDNA copy number in yeast is therefore a highly dynamic phenotype.
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Affiliation(s)
- Ben Galeota-Sprung
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - Amy Fernandez
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - Paul Sniegowski
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA
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28
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Abstract
Abstract
Mitochondria, the cell powerhouse, are membrane-bound organelles present in the cytoplasm of almost all the eukaryotic cells. Their main function is to generate energy in the form of adenosine triphosphate (ATP). In addition, mitochondria store calcium for the cell signaling activities, generate heat, harbor pathways of intermediate metabolism and mediate cell growth and death. Primary mitochondrial diseases (MDs) form a clinically as well as genetically heterogeneous group of inherited disorders that result from the mitochondrial energetic metabolism malfunctions. The lifetime risk of the MDs development is estimated at 1:1470 of newborns, which makes them one of the most recurrent groups of inherited disorders with an important burden for society.
MDs are progressive with wide range of symptoms of variable severity that can emerge congenitally or anytime during the life. MD can be caused by mutations in the mitochondrial DNA (mtDNA) or nuclear DNA genes. Mutations inducing impairment of mitochondrial function have been found in more than 400 genes. Furthermore, more than 1200 nuclear genes, which could play a role in the MDs’ genetic etiology, are involved in the mitochondrial activities. However, the knowledge regarding the mechanism of the mitochondrial pathogenicity appears to be most essential for the development of effective patient’s treatment suffering from the mitochondrial disease. This is an overview update focused on the mitochondrial biology and the mitochondrial diseases associated genes.
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Manini A, Caporali L, Meneri M, Zanotti S, Piga D, Arena IG, Corti S, Toscano A, Comi GP, Musumeci O, Carelli V, Ronchi D. Case Report: Rare Homozygous RNASEH1 Mutations Associated With Adult-Onset Mitochondrial Encephalomyopathy and Multiple Mitochondrial DNA Deletions. Front Genet 2022; 13:906667. [PMID: 35711919 PMCID: PMC9194440 DOI: 10.3389/fgene.2022.906667] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 04/25/2022] [Indexed: 12/02/2022] Open
Abstract
Mitochondrial DNA (mtDNA) maintenance disorders embrace a broad range of clinical syndromes distinguished by the evidence of mtDNA depletion and/or deletions in affected tissues. Among the nuclear genes associated with mtDNA maintenance disorders, RNASEH1 mutations produce a homogeneous phenotype, with progressive external ophthalmoplegia (PEO), ptosis, limb weakness, cerebellar ataxia, and dysphagia. The encoded enzyme, ribonuclease H1, is involved in mtDNA replication, whose impairment leads to an increase in replication intermediates resulting from mtDNA replication slowdown. Here, we describe two unrelated Italian probands (Patient 1 and Patient 2) affected by chronic PEO, ptosis, and muscle weakness. Cerebellar features and severe dysphagia requiring enteral feeding were observed in one patient. In both cases, muscle biopsy revealed diffuse mitochondrial abnormalities and multiple mtDNA deletions. A targeted next-generation sequencing analysis revealed the homozygous RNASEH1 mutations c.129-3C>G and c.424G>A in patients 1 and 2, respectively. The c.129-3C>G substitution has never been described as disease-related and resulted in the loss of exon 2 in Patient 1 muscle RNASEH1 transcript. Overall, we recommend implementing the use of high-throughput sequencing approaches in the clinical setting to reach genetic diagnosis in case of suspected presentations with impaired mtDNA homeostasis.
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Affiliation(s)
- Arianna Manini
- Dino Ferrari Center, Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy
| | - Leonardo Caporali
- Istituto delle Scienze Neurologiche di Bologna, Programma di Neurogenetica, Bologna, Italy
| | - Megi Meneri
- Dino Ferrari Center, Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy.,Foundation IRCCS Ca' Granda Ospedale Maggiore Policlinico, Neurology Unit, Department of Neuroscience, Milan, Italy
| | - Simona Zanotti
- Foundation IRCCS Ca' Granda Ospedale Maggiore Policlinico, Neuromuscular and Rare Diseases Unit, Department of Neuroscience, Milan, Italy
| | - Daniela Piga
- Foundation IRCCS Ca' Granda Ospedale Maggiore Policlinico, Neurology Unit, Department of Neuroscience, Milan, Italy
| | - Ignazio Giuseppe Arena
- Unit of Neurology and Neuromuscular disorders, Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - Stefania Corti
- Dino Ferrari Center, Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy.,Foundation IRCCS Ca' Granda Ospedale Maggiore Policlinico, Neurology Unit, Department of Neuroscience, Milan, Italy
| | - Antonio Toscano
- Unit of Neurology and Neuromuscular disorders, Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - Giacomo Pietro Comi
- Dino Ferrari Center, Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy.,Foundation IRCCS Ca' Granda Ospedale Maggiore Policlinico, Neuromuscular and Rare Diseases Unit, Department of Neuroscience, Milan, Italy
| | - Olimpia Musumeci
- Unit of Neurology and Neuromuscular disorders, Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - Valerio Carelli
- Istituto delle Scienze Neurologiche di Bologna, Programma di Neurogenetica, Bologna, Italy.,Dipartimento di Scienze Biomediche e Neuromotorie (DIBINEM), University of Bologna, Bologna, Italy
| | - Dario Ronchi
- Dino Ferrari Center, Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy.,Foundation IRCCS Ca' Granda Ospedale Maggiore Policlinico, Neurology Unit, Department of Neuroscience, Milan, Italy
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Roy A, Kandettu A, Ray S, Chakrabarty S. Mitochondrial DNA replication and repair defects: Clinical phenotypes and therapeutic interventions. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2022; 1863:148554. [PMID: 35341749 DOI: 10.1016/j.bbabio.2022.148554] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 03/06/2022] [Accepted: 03/16/2022] [Indexed: 12/15/2022]
Abstract
Mitochondria is a unique cellular organelle involved in multiple cellular processes and is critical for maintaining cellular homeostasis. This semi-autonomous organelle contains its circular genome - mtDNA (mitochondrial DNA), that undergoes continuous cycles of replication and repair to maintain the mitochondrial genome integrity. The majority of the mitochondrial genes, including mitochondrial replisome and repair genes, are nuclear-encoded. Although the repair machinery of mitochondria is quite efficient, the mitochondrial genome is highly susceptible to oxidative damage and other types of exogenous and endogenous agent-induced DNA damage, due to the absence of protective histones and their proximity to the main ROS production sites. Mutations in replication and repair genes of mitochondria can result in mtDNA depletion and deletions subsequently leading to mitochondrial genome instability. The combined action of mutations and deletions can result in compromised mitochondrial genome maintenance and lead to various mitochondrial disorders. Here, we review the mechanism of mitochondrial DNA replication and repair process, key proteins involved, and their altered function in mitochondrial disorders. The focus of this review will be on the key genes of mitochondrial DNA replication and repair machinery and the clinical phenotypes associated with mutations in these genes.
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Affiliation(s)
- Abhipsa Roy
- Department of Cell and Molecular Biology, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal 576104, Karnataka, India
| | - Amoolya Kandettu
- Department of Cell and Molecular Biology, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal 576104, Karnataka, India
| | - Swagat Ray
- Department of Life Sciences, School of Life and Environmental Sciences, University of Lincoln, Lincoln LN6 7TS, United Kingdom
| | - Sanjiban Chakrabarty
- Department of Cell and Molecular Biology, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal 576104, Karnataka, India.
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Milenkovic D, Sanz-Moreno A, Calzada-Wack J, Rathkolb B, Veronica Amarie O, Gerlini R, Aguilar-Pimentel A, Misic J, Simard ML, Wolf E, Fuchs H, Gailus-Durner V, de Angelis MH, Larsson NG. Mice lacking the mitochondrial exonuclease MGME1 develop inflammatory kidney disease with glomerular dysfunction. PLoS Genet 2022; 18:e1010190. [PMID: 35533204 PMCID: PMC9119528 DOI: 10.1371/journal.pgen.1010190] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 05/19/2022] [Accepted: 04/05/2022] [Indexed: 12/27/2022] Open
Abstract
Mitochondrial DNA (mtDNA) maintenance disorders are caused by mutations in ubiquitously expressed nuclear genes and lead to syndromes with variable disease severity and tissue-specific phenotypes. Loss of function mutations in the gene encoding the mitochondrial genome and maintenance exonuclease 1 (MGME1) result in deletions and depletion of mtDNA leading to adult-onset multisystem mitochondrial disease in humans. To better understand the in vivo function of MGME1 and the associated disease pathophysiology, we characterized a Mgme1 mouse knockout model by extensive phenotyping of ageing knockout animals. We show that loss of MGME1 leads to de novo formation of linear deleted mtDNA fragments that are constantly made and degraded. These findings contradict previous proposal that MGME1 is essential for degradation of linear mtDNA fragments and instead support a model where MGME1 has a critical role in completion of mtDNA replication. We report that Mgme1 knockout mice develop a dramatic phenotype as they age and display progressive weight loss, cataract and retinopathy. Surprisingly, aged animals also develop kidney inflammation, glomerular changes and severe chronic progressive nephropathy, consistent with nephrotic syndrome. These findings link the faulty mtDNA synthesis to severe inflammatory disease and thus show that defective mtDNA replication can trigger an immune response that causes age-associated progressive pathology in the kidney. We have addressed the controversy of the role of the mitochondrial genome and maintenance exonuclease 1 (MGME1) in mtDNA metabolism by characterization of knockout mice. Our findings show that loss of MGME1 leads to increased de novo formation of linear deleted mtDNA, thus contradicting previous report that MGME1 degrades long linear mtDNA molecules. In addition, we report that loss of MGME1 leads to age-associated pathology manifested as progressive weight loss, cataract and retinopathy. Aged knockout mice also develop kidney inflammation leading to glomerular changes, fibrosis and nephrotic syndrome. Defective mtDNA replication causing the formation of linear deleted mtDNA can thus trigger an immune response that leads to the development of progressive kidney disease in ageing animals.
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Affiliation(s)
| | - Adrián Sanz-Moreno
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health GmbH, Neuherberg, Germany
| | - Julia Calzada-Wack
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health GmbH, Neuherberg, Germany
| | - Birgit Rathkolb
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health GmbH, Neuherberg, Germany
- Institute of Molecular Animal Breeding and Biotechnology, Gene Center, Ludwig-Maximilians-University Munich, Munich, Germany
- German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Oana Veronica Amarie
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health GmbH, Neuherberg, Germany
| | - Raffaele Gerlini
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health GmbH, Neuherberg, Germany
- German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Antonio Aguilar-Pimentel
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health GmbH, Neuherberg, Germany
| | - Jelena Misic
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | | | - Eckhard Wolf
- Institute of Molecular Animal Breeding and Biotechnology, Gene Center, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Helmut Fuchs
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health GmbH, Neuherberg, Germany
| | - Valerie Gailus-Durner
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health GmbH, Neuherberg, Germany
| | - Martin Hrabě de Angelis
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health GmbH, Neuherberg, Germany
- German Center for Diabetes Research (DZD), Neuherberg, Germany
- Chair of Experimental Genetics, TUM School of Life Sciences, Technische Universität München, Freising, Germany
- * E-mail: (NGL); (MH)
| | - Nils-Göran Larsson
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
- * E-mail: (NGL); (MH)
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Yépez VA, Gusic M, Kopajtich R, Mertes C, Smith NH, Alston CL, Ban R, Beblo S, Berutti R, Blessing H, Ciara E, Distelmaier F, Freisinger P, Häberle J, Hayflick SJ, Hempel M, Itkis YS, Kishita Y, Klopstock T, Krylova TD, Lamperti C, Lenz D, Makowski C, Mosegaard S, Müller MF, Muñoz-Pujol G, Nadel A, Ohtake A, Okazaki Y, Procopio E, Schwarzmayr T, Smet J, Staufner C, Stenton SL, Strom TM, Terrile C, Tort F, Van Coster R, Vanlander A, Wagner M, Xu M, Fang F, Ghezzi D, Mayr JA, Piekutowska-Abramczuk D, Ribes A, Rötig A, Taylor RW, Wortmann SB, Murayama K, Meitinger T, Gagneur J, Prokisch H. Clinical implementation of RNA sequencing for Mendelian disease diagnostics. Genome Med 2022; 14:38. [PMID: 35379322 PMCID: PMC8981716 DOI: 10.1186/s13073-022-01019-9] [Citation(s) in RCA: 80] [Impact Index Per Article: 40.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 02/03/2022] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Lack of functional evidence hampers variant interpretation, leaving a large proportion of individuals with a suspected Mendelian disorder without genetic diagnosis after whole genome or whole exome sequencing (WES). Research studies advocate to further sequence transcriptomes to directly and systematically probe gene expression defects. However, collection of additional biopsies and establishment of lab workflows, analytical pipelines, and defined concepts in clinical interpretation of aberrant gene expression are still needed for adopting RNA sequencing (RNA-seq) in routine diagnostics. METHODS We implemented an automated RNA-seq protocol and a computational workflow with which we analyzed skin fibroblasts of 303 individuals with a suspected mitochondrial disease that previously underwent WES. We also assessed through simulations how aberrant expression and mono-allelic expression tests depend on RNA-seq coverage. RESULTS We detected on average 12,500 genes per sample including around 60% of all disease genes-a coverage substantially higher than with whole blood, supporting the use of skin biopsies. We prioritized genes demonstrating aberrant expression, aberrant splicing, or mono-allelic expression. The pipeline required less than 1 week from sample preparation to result reporting and provided a median of eight disease-associated genes per patient for inspection. A genetic diagnosis was established for 16% of the 205 WES-inconclusive cases. Detection of aberrant expression was a major contributor to diagnosis including instances of 50% reduction, which, together with mono-allelic expression, allowed for the diagnosis of dominant disorders caused by haploinsufficiency. Moreover, calling aberrant splicing and variants from RNA-seq data enabled detecting and validating splice-disrupting variants, of which the majority fell outside WES-covered regions. CONCLUSION Together, these results show that streamlined experimental and computational processes can accelerate the implementation of RNA-seq in routine diagnostics.
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Affiliation(s)
- Vicente A. Yépez
- Institute of Human Genetics, School of Medicine, Technical University of Munich, Munich, Germany
- Department of Informatics, Technical University of Munich, Garching, Germany
- Quantitative Biosciences Munich, Department of Biochemistry, Ludwig-Maximilians-Universität, Munich, Germany
| | - Mirjana Gusic
- Institute of Human Genetics, School of Medicine, Technical University of Munich, Munich, Germany
- Institute of Neurogenomics, Helmholtz Zentrum München, Neuherberg, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Munich Heart Alliance, Munich, Germany
| | - Robert Kopajtich
- Institute of Human Genetics, School of Medicine, Technical University of Munich, Munich, Germany
- Institute of Neurogenomics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Christian Mertes
- Department of Informatics, Technical University of Munich, Garching, Germany
| | - Nicholas H. Smith
- Department of Informatics, Technical University of Munich, Garching, Germany
| | - Charlotte L. Alston
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4HH UK
- NHS Highly Specialised Services for Rare Mitochondrial Disorders, Royal Victoria Infirmary, Newcastle upon Tyne Hospitals NHS Foundation Trust, Queen Victoria Road, Newcastle upon Tyne, NE1 4LP UK
| | - Rui Ban
- Institute of Neurogenomics, Helmholtz Zentrum München, Neuherberg, Germany
- Department of Pediatric Neurology, Beijing Children’s Hospital, Capital Medical University, National Center for Children’s Health, Beijing, China
| | - Skadi Beblo
- Department of Women and Child Health, Hospital for Children and Adolescents, Center for Pediatric Research Leipzig (CPL), Center for Rare Diseases, University Hospitals, University of Leipzig, Leipzig, Germany
| | - Riccardo Berutti
- Institute of Human Genetics, School of Medicine, Technical University of Munich, Munich, Germany
- Institute of Neurogenomics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Holger Blessing
- Department for Inborn Metabolic Diseases, Children’s and Adolescents’ Hospital, University of Erlangen-Nürnberg, Erlangen, Germany
| | - Elżbieta Ciara
- Department of Medical Genetics, Children’s Memorial Health Institute, Warsaw, Poland
| | - Felix Distelmaier
- Department of General Pediatrics, Neonatology and Pediatric Cardiology, Heinrich-Heine-University, Düsseldorf, Germany
| | - Peter Freisinger
- Department of Pediatrics, Klinikum Reutlingen, Reutlingen, Germany
| | - Johannes Häberle
- University Children’s Hospital Zurich and Children’s Research Centre, Zürich, Switzerland
| | - Susan J. Hayflick
- Department of Molecular and Medical Genetics, Oregon Health & Science University, Portland, USA
| | - Maja Hempel
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | | | - Yoshihito Kishita
- Diagnostics and Therapeutics of Intractable Diseases, Intractable Disease Research Center, Juntendo University, Graduate School of Medicine, Tokyo, Japan
- Department of Life Science, Faculty of Science and Engineering, Kindai University, Osaka, Japan
| | - Thomas Klopstock
- Department of Neurology, Friedrich-Baur-Institute, University Hospital, Ludwig-Maximilians-Universität, Munich, Germany
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | | | - Costanza Lamperti
- Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS (Istituto di Ricovero e Cura a Carattere Scientifico) Istituto Neurologico Carlo Besta, Milan, Italy
| | - Dominic Lenz
- Division of Neuropediatrics and Pediatric Metabolic Medicine, Center for Pediatric and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Christine Makowski
- Department of Pediatrics, Technical University of Munich, Munich, Germany
| | - Signe Mosegaard
- Research Unit for Molecular Medicine, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Michaela F. Müller
- Department of Informatics, Technical University of Munich, Garching, Germany
| | - Gerard Muñoz-Pujol
- Section of Inborn Errors of Metabolism-IBC, Department of Biochemistry and Molecular Genetics, Hospital Clínic, IDIBAPS, CIBERER, Barcelona, Spain
| | - Agnieszka Nadel
- Institute of Human Genetics, School of Medicine, Technical University of Munich, Munich, Germany
- Institute of Neurogenomics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Akira Ohtake
- Department of Pediatrics & Clinical Genomics, Faculty of Medicine, Saitama Medical University, Saitama, Japan
- Center for Intractable Diseases, Saitama Medical University Hospital, Saitama, Japan
| | - Yasushi Okazaki
- Diagnostics and Therapeutics of Intractable Diseases, Intractable Disease Research Center, Juntendo University, Graduate School of Medicine, Tokyo, Japan
| | - Elena Procopio
- Inborn Metabolic and Muscular Disorders Unit, Anna Meyer Children Hospital, Florence, Italy
| | - Thomas Schwarzmayr
- Institute of Human Genetics, School of Medicine, Technical University of Munich, Munich, Germany
- Institute of Neurogenomics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Joél Smet
- Department of Pediatric Neurology and Metabolism, Ghent University Hospital, Ghent, Belgium
| | - Christian Staufner
- Division of Neuropediatrics and Pediatric Metabolic Medicine, Center for Pediatric and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Sarah L. Stenton
- Institute of Human Genetics, School of Medicine, Technical University of Munich, Munich, Germany
- Institute of Neurogenomics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Tim M. Strom
- Institute of Human Genetics, School of Medicine, Technical University of Munich, Munich, Germany
- Institute of Neurogenomics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Caterina Terrile
- Institute of Neurogenomics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Frederic Tort
- Section of Inborn Errors of Metabolism-IBC, Department of Biochemistry and Molecular Genetics, Hospital Clínic, IDIBAPS, CIBERER, Barcelona, Spain
| | - Rudy Van Coster
- Department of Pediatric Neurology and Metabolism, Ghent University Hospital, Ghent, Belgium
| | - Arnaud Vanlander
- Department of Pediatric Neurology and Metabolism, Ghent University Hospital, Ghent, Belgium
| | - Matias Wagner
- Institute of Human Genetics, School of Medicine, Technical University of Munich, Munich, Germany
- Institute of Neurogenomics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Manting Xu
- Institute of Neurogenomics, Helmholtz Zentrum München, Neuherberg, Germany
- Department of Pediatric Neurology, Beijing Children’s Hospital, Capital Medical University, National Center for Children’s Health, Beijing, China
| | - Fang Fang
- Department of Pediatric Neurology, Beijing Children’s Hospital, Capital Medical University, National Center for Children’s Health, Beijing, China
| | - Daniele Ghezzi
- Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS (Istituto di Ricovero e Cura a Carattere Scientifico) Istituto Neurologico Carlo Besta, Milan, Italy
- Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy
| | - Johannes A. Mayr
- University Children’s Hospital, Paracelsus Medical University Salzburg, Salzburg, Austria
| | | | - Antonia Ribes
- Section of Inborn Errors of Metabolism-IBC, Department of Biochemistry and Molecular Genetics, Hospital Clínic, IDIBAPS, CIBERER, Barcelona, Spain
| | - Agnès Rötig
- Université de Paris, Institut Imagine, INSERM UMR 1163, Paris, France
| | - Robert W. Taylor
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4HH UK
- NHS Highly Specialised Services for Rare Mitochondrial Disorders, Royal Victoria Infirmary, Newcastle upon Tyne Hospitals NHS Foundation Trust, Queen Victoria Road, Newcastle upon Tyne, NE1 4LP UK
| | - Saskia B. Wortmann
- Institute of Human Genetics, School of Medicine, Technical University of Munich, Munich, Germany
- University Children’s Hospital, Paracelsus Medical University Salzburg, Salzburg, Austria
- Amalia Children’s Hospital, Radboudumc Nijmegen, Nijmegen, The Netherlands
| | - Kei Murayama
- Department of Metabolism, Chiba Children’s Hospital, Chiba, Japan
| | - Thomas Meitinger
- Institute of Human Genetics, School of Medicine, Technical University of Munich, Munich, Germany
| | - Julien Gagneur
- Institute of Human Genetics, School of Medicine, Technical University of Munich, Munich, Germany
- Department of Informatics, Technical University of Munich, Garching, Germany
- Institute of Computational Biology, Helmholtz Zentrum München, Neuherberg, Germany
| | - Holger Prokisch
- Institute of Human Genetics, School of Medicine, Technical University of Munich, Munich, Germany
- Institute of Neurogenomics, Helmholtz Zentrum München, Neuherberg, Germany
- Department of Pediatric Neurology, Beijing Children’s Hospital, Capital Medical University, National Center for Children’s Health, Beijing, China
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Manini A, Abati E, Comi GP, Corti S, Ronchi D. Mitochondrial DNA homeostasis impairment and dopaminergic dysfunction: A trembling balance. Ageing Res Rev 2022; 76:101578. [PMID: 35114397 DOI: 10.1016/j.arr.2022.101578] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 12/26/2021] [Accepted: 01/28/2022] [Indexed: 02/07/2023]
Abstract
Maintenance of mitochondrial DNA (mtDNA) homeostasis includes a variety of processes, such as mtDNA replication, repair, and nucleotides synthesis, aimed at preserving the structural and functional integrity of mtDNA molecules. Mutations in several nuclear genes (i.e., POLG, POLG2, TWNK, OPA1, DGUOK, MPV17, TYMP) impair mtDNA maintenance, leading to clinical syndromes characterized by mtDNA depletion and/or deletions in affected tissues. In the past decades, studies have demonstrated a progressive accumulation of multiple mtDNA deletions in dopaminergic neurons of the substantia nigra in elderly population and, to a greater extent, in Parkinson's disease patients. Moreover, parkinsonism has been frequently described as a prominent clinical feature in mtDNA instability syndromes. Among Parkinson's disease-related genes with a significant role in mitochondrial biology, PARK2 and LRRK2 specifically take part in mtDNA maintenance. Moreover, a variety of murine models (i.e., "Mutator", "MitoPark", "PD-mitoPstI", "Deletor", "Twinkle-dup" and "TwinkPark") provided in vivo evidence that mtDNA stability is required to preserve nigrostriatal integrity. Here, we review and discuss the clinical, genetic, and pathological background underlining the link between impaired mtDNA homeostasis and dopaminergic degeneration.
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Berardo A, Engelstad K, Hirano M. Advances in Thymidine Kinase 2 Deficiency: Clinical Aspects, Translational Progress, and Emerging Therapies. J Neuromuscul Dis 2022; 9:225-235. [PMID: 35094997 PMCID: PMC9028656 DOI: 10.3233/jnd-210786] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Defects in the replication, maintenance, and repair of mitochondrial DNA (mtDNA) constitute a growing and genetically heterogeneous group of mitochondrial disorders. Multiple genes participate in these processes, including thymidine kinase 2 (TK2) encoding the mitochondrial matrix protein TK2, a critical component of the mitochondrial nucleotide salvage pathway. TK2 deficiency (TK2d) causes mtDNA depletion, multiple deletions, or both, which manifest predominantly as mitochondrial myopathy. A wide clinical spectrum phenotype includes a severe, rapidly progressive, early onset form (median survival: < 2 years); a less severe childhood-onset form; and a late-onset form with a variably slower rate of progression. Clinical presentation typically includes progressive weakness of limb, neck, facial, oropharyngeal, and respiratory muscle, whereas limb myopathy with ptosis, ophthalmoparesis, and respiratory involvement is more common in the late-onset form. Deoxynucleoside monophosphates and deoxynucleosides that can bypass the TK2 enzyme defect have been assessed in a mouse model, as well as under open-label compassionate use (expanded access) in TK2d patients, indicating clinical efficacy with a favorable side-effect profile. This treatment is currently undergoing testing in clinical trials intended to support approval in the US and European Union (EU). In the early expanded access program, growth differentiation factor 15 (GDF-15) appears to be a useful biomarker that correlates with therapeutic response. With the advent of a specific treatment and given the high morbidity and mortality associated with TK2d, clinicians need to know how to recognize and diagnose this disorder. Here, we summarize translational research about this rare condition emphasizing clinical aspects.
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Affiliation(s)
- Andres Berardo
- Department of Neurology, Columbia University Irving Medical Center, New York, NY, USA
| | - Kristin Engelstad
- Department of Neurology, Columbia University Irving Medical Center, New York, NY, USA
| | - Michio Hirano
- Department of Neurology, Columbia University Irving Medical Center, New York, NY, USA
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35
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Molecular Genetics Overview of Primary Mitochondrial Myopathies. J Clin Med 2022; 11:jcm11030632. [PMID: 35160083 PMCID: PMC8836969 DOI: 10.3390/jcm11030632] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 01/13/2022] [Accepted: 01/20/2022] [Indexed: 12/29/2022] Open
Abstract
Mitochondrial disorders are the most common inherited conditions, characterized by defects in oxidative phosphorylation and caused by mutations in nuclear or mitochondrial genes. Due to its high energy request, skeletal muscle is typically involved. According to the International Workshop of Experts in Mitochondrial Diseases held in Rome in 2016, the term Primary Mitochondrial Myopathy (PMM) should refer to those mitochondrial disorders affecting principally, but not exclusively, the skeletal muscle. The clinical presentation may include general isolated myopathy with muscle weakness, exercise intolerance, chronic ophthalmoplegia/ophthalmoparesis (cPEO) and eyelids ptosis, or multisystem conditions where there is a coexistence with extramuscular signs and symptoms. In recent years, new therapeutic targets have been identified leading to the launch of some promising clinical trials that have mainly focused on treating muscle symptoms and that require populations with defined genotype. Advantages in next-generation sequencing techniques have substantially improved diagnosis. So far, an increasing number of mutations have been identified as responsible for mitochondrial disorders. In this review, we focused on the principal molecular genetic alterations in PMM. Accordingly, we carried out a comprehensive review of the literature and briefly discussed the possible approaches which could guide the clinician to a genetic diagnosis.
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Longchamps RJ, Yang SY, Castellani CA, Shi W, Lane J, Grove ML, Bartz TM, Sarnowski C, Liu C, Burrows K, Guyatt AL, Gaunt TR, Kacprowski T, Yang J, De Jager PL, Yu L, Bergman A, Xia R, Fornage M, Feitosa MF, Wojczynski MK, Kraja AT, Province MA, Amin N, Rivadeneira F, Tiemeier H, Uitterlinden AG, Broer L, Van Meurs JBJ, Van Duijn CM, Raffield LM, Lange L, Rich SS, Lemaitre RN, Goodarzi MO, Sitlani CM, Mak ACY, Bennett DA, Rodriguez S, Murabito JM, Lunetta KL, Sotoodehnia N, Atzmon G, Ye K, Barzilai N, Brody JA, Psaty BM, Taylor KD, Rotter JI, Boerwinkle E, Pankratz N, Arking DE. Genome-wide analysis of mitochondrial DNA copy number reveals loci implicated in nucleotide metabolism, platelet activation, and megakaryocyte proliferation. Hum Genet 2022; 141:127-146. [PMID: 34859289 PMCID: PMC8758627 DOI: 10.1007/s00439-021-02394-w] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 10/22/2021] [Indexed: 12/18/2022]
Abstract
Mitochondrial DNA copy number (mtDNA-CN) measured from blood specimens is a minimally invasive marker of mitochondrial function that exhibits both inter-individual and intercellular variation. To identify genes involved in regulating mitochondrial function, we performed a genome-wide association study (GWAS) in 465,809 White individuals from the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) consortium and the UK Biobank (UKB). We identified 133 SNPs with statistically significant, independent effects associated with mtDNA-CN across 100 loci. A combination of fine-mapping, variant annotation, and co-localization analyses was used to prioritize genes within each of the 133 independent sites. Putative causal genes were enriched for known mitochondrial DNA depletion syndromes (p = 3.09 × 10-15) and the gene ontology (GO) terms for mtDNA metabolism (p = 1.43 × 10-8) and mtDNA replication (p = 1.2 × 10-7). A clustering approach leveraged pleiotropy between mtDNA-CN associated SNPs and 41 mtDNA-CN associated phenotypes to identify functional domains, revealing three distinct groups, including platelet activation, megakaryocyte proliferation, and mtDNA metabolism. Finally, using mitochondrial SNPs, we establish causal relationships between mitochondrial function and a variety of blood cell-related traits, kidney function, liver function and overall (p = 0.044) and non-cancer mortality (p = 6.56 × 10-4).
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Affiliation(s)
- R J Longchamps
- Department of Genetic Medicine, McKusick-Nathans Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - S Y Yang
- Department of Genetic Medicine, McKusick-Nathans Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - C A Castellani
- Department of Genetic Medicine, McKusick-Nathans Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Pathology and Laboratory Medicine, Western University, London, ON, Canada
| | - W Shi
- Department of Genetic Medicine, McKusick-Nathans Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - J Lane
- Department of Laboratory Medicine and Pathology, University of Minnesota Medical School, Minneapolis, MN, USA
| | - M L Grove
- Department of Epidemiology, Human Genetics, and Environmental Sciences, School of Public Health, Human Genetics Center, The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - T M Bartz
- Cardiovascular Health Research Unit, Departments of Medicine and Biostatistics, University of Washington, Seattle, WA, USA
| | - C Sarnowski
- Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA
| | - C Liu
- Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA
| | - K Burrows
- MRC Integrative Epidemiology Unit at the University of Bristol, University of Bristol, Oakfield House, Oakfield Grove, Bristol, UK
- Population Health Sciences, Bristol Medical School, University of Bristol, Oakfield House, Oakfield Grove, Bristol, UK
| | - A L Guyatt
- Department of Health Sciences, University of Leicester, University Road, Leicester, UK
| | - T R Gaunt
- MRC Integrative Epidemiology Unit at the University of Bristol, University of Bristol, Oakfield House, Oakfield Grove, Bristol, UK
- Population Health Sciences, Bristol Medical School, University of Bristol, Oakfield House, Oakfield Grove, Bristol, UK
| | - T Kacprowski
- Department of Functional Genomics, Interfaculty Institute for Genetics and Functional Genomics, University of Greifswald, Greifswald, Germany
- Data Science in Biomedicine, Peter L. Reichertz Institute for Medical Informatics, TU Braunschweig and Hannover Medical School, Brunswick, Germany
| | - J Yang
- Rush Alzheimer's Disease Center and Department of Neurological Sciences, Rush University Medical Center, Chicago, IL, USA
| | - P L De Jager
- Center for Translational and Systems Neuroimmunology, Department of Neurology, Columbia University Medical Center, New York, NY, USA
- Program in Medical and Population Genetics, Broad Institute, Cambridge, MA, USA
| | - L Yu
- Rush Alzheimer's Disease Center and Department of Neurological Sciences, Rush University Medical Center, Chicago, IL, USA
| | - A Bergman
- Department of Systems and Computational Biology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - R Xia
- Institute of Molecular Medicine, The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - M Fornage
- Institute of Molecular Medicine, The University of Texas Health Science Center at Houston, Houston, TX, USA
- Human Genetics Center, The University of Texas Health Science Center at Houston, Houston, USA
| | - M F Feitosa
- Division of Statistical Genomics, Department of Genetics, Washington University School of Medicine, St. Louis, USA
| | - M K Wojczynski
- Division of Statistical Genomics, Department of Genetics, Washington University School of Medicine, St. Louis, USA
| | - A T Kraja
- Division of Statistical Genomics, Department of Genetics, Washington University School of Medicine, St. Louis, USA
| | - M A Province
- Division of Statistical Genomics, Department of Genetics, Washington University School of Medicine, St. Louis, USA
| | - N Amin
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - F Rivadeneira
- Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
| | - H Tiemeier
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands
- Department of Social and Behavioral Science, Harvard T.H. School of Public Health, Boston, USA
| | - A G Uitterlinden
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands
- Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
| | - L Broer
- Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
| | - J B J Van Meurs
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands
- Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
| | - C M Van Duijn
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - L M Raffield
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - L Lange
- Department of Medicine, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA
| | - S S Rich
- Center for Public Health Genomics, University of Virginia, Charlottesville, VA, USA
| | - R N Lemaitre
- Cardiovascular Health Research Unit, Department of Medicine, University of Washington, Seattle, WA, USA
| | - M O Goodarzi
- Division of Endocrinology, Diabetes and Metabolism, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - C M Sitlani
- Cardiovascular Health Research Unit, Department of Medicine, University of Washington, Seattle, WA, USA
| | - A C Y Mak
- Cardiovascular Research Institute and Institute for Human Genetics, University of California, San Francisco, CA, USA
| | - D A Bennett
- Rush Alzheimer's Disease Center and Department of Neurological Sciences, Rush University Medical Center, Chicago, IL, USA
| | - S Rodriguez
- MRC Integrative Epidemiology Unit at the University of Bristol, University of Bristol, Oakfield House, Oakfield Grove, Bristol, UK
- Population Health Sciences, Bristol Medical School, University of Bristol, Oakfield House, Oakfield Grove, Bristol, UK
| | - J M Murabito
- Boston University School of Medicine, Boston University, Boston, MA, USA
| | - K L Lunetta
- Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA
| | - N Sotoodehnia
- Cardiovascular Health Research Unit, Division of Cardiology, University of Washington, Seattle, WA, USA
| | - G Atzmon
- Department of Natural Science, University of Haifa, Haifa, Israel
- Departments of Medicine and Genetics, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - K Ye
- Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - N Barzilai
- Departments of Medicine and Genetics, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - J A Brody
- Cardiovascular Health Research Unit, Department of Medicine, University of Washington, Seattle, WA, USA
| | - B M Psaty
- Cardiovascular Health Research Unit, Departments of Epidemiology, Medicine and Health Services, University of Washington, Seattle, WA, USA
| | - K D Taylor
- The Institute for Translational Genomics and Population Sciences, Department of Pediatrics, The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, CA, USA
| | - J I Rotter
- The Institute for Translational Genomics and Population Sciences, Department of Pediatrics, The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, CA, USA
| | - E Boerwinkle
- Department of Epidemiology, Human Genetics, and Environmental Sciences, School of Public Health, Human Genetics Center, The University of Texas Health Science Center at Houston, Houston, TX, USA
- Baylor College of Medicine, Human Genome Sequencing Center, Houston, TX, USA
| | - N Pankratz
- Department of Laboratory Medicine and Pathology, University of Minnesota Medical School, Minneapolis, MN, USA
| | - D E Arking
- Department of Genetic Medicine, McKusick-Nathans Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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Olimpio C, Tiet MY, Horvath R. Primary mitochondrial myopathies in childhood. Neuromuscul Disord 2021; 31:978-987. [PMID: 34736635 DOI: 10.1016/j.nmd.2021.08.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 07/29/2021] [Accepted: 08/05/2021] [Indexed: 12/30/2022]
Abstract
Primary mitochondrial myopathies are genetic metabolic disorders of mitochondrial dysfunction affecting mainly, but not exclusively, skeletal muscle. Although individually rare, they are the most common inherited metabolic disorders in childhood. They can be similar to other childhood muscle diseases such as congenital myopathies, dystrophies, myasthenic syndromes or metabolic myopathies and a muscle biopsy and genetic testing are important in the differential diagnosis. Mitochondrial myopathies can present at any age but typically childhood onset myopathies have more significant muscle involvement and are caused by genes encoded in the nuclear DNA. Mitochondrial myopathy in infants presents with hypotonia, muscle weakness and difficulty feeding. In toddlers and older children delayed motor development, exercise intolerance and premature fatigue are common. A number of nuclear DNA and mitochondrial DNA encoded genes are known to cause isolated myopathy in childhood and they are important in a range of mitochondrial functions such as oxidative phosphorylation, mitochondrial transcription/translation and mitochondrial fusion/fission. A rare cause of isolated myopathy in children, reversible infantile respiratory chain deficiency myopathy, is non-progressive and typically associated with spontaneous full recovery. Promising targeted treatments have been reported for a number or mitochondrial myopathies including riboflavin in ACAD9 and ETFDH-myopathies and deoxynucleoside for TK2-related disease.
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Affiliation(s)
- Catarina Olimpio
- East Anglian Medical Genetics Service, Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom
| | - May Yung Tiet
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
| | - Rita Horvath
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom.
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Morganti C, Ito K. Mitochondrial Contributions to Hematopoietic Stem Cell Aging. Int J Mol Sci 2021; 22:11117. [PMID: 34681777 PMCID: PMC8537916 DOI: 10.3390/ijms222011117] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 10/11/2021] [Accepted: 10/13/2021] [Indexed: 02/07/2023] Open
Abstract
Mitochondrial dysfunction and stem cell exhaustion are two hallmarks of aging. In the hematopoietic system, aging is linked to imbalanced immune response and reduced regenerative capacity in hematopoietic stem cells (HSCs), as well as an increased predisposition to a spectrum of diseases, including myelodysplastic syndrome and acute myeloid leukemia. Myeloid-biased differentiation and loss of polarity are distinct features of aged HSCs, which generally exhibit enhanced mitochondrial oxidative phosphorylation and increased production of reactive oxygen species (ROS), suggesting a direct role for mitochondria in the degenerative process. Here, we provide an overview of current knowledge of the mitochondrial mechanisms that contribute to age-related phenotypes in HSCs. These include mitochondrial ROS production, alteration/activation of mitochondrial metabolism, the quality control pathway of mitochondria, and inflammation. Greater understanding of the key machineries of HSC aging will allow us to identify new therapeutic targets for preventing, delaying, or even reversing aspects of this process.
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Affiliation(s)
- Claudia Morganti
- Ruth L. and David S. Gottesman Institute for Stem Cell and Regenerative Medicine Research, Albert Einstein College of Medicine, Bronx, NY 10461, USA;
- Departments of Cell Biology and Stem Cell Institute, Albert Einstein College of Medicine, Bronx, NY 10461, USA
- Department of Medicine, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Keisuke Ito
- Ruth L. and David S. Gottesman Institute for Stem Cell and Regenerative Medicine Research, Albert Einstein College of Medicine, Bronx, NY 10461, USA;
- Departments of Cell Biology and Stem Cell Institute, Albert Einstein College of Medicine, Bronx, NY 10461, USA
- Department of Medicine, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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Gayathri N, Deepha S, Sharma S. Diagnosis of primary mitochondrial disorders -Emphasis on myopathological aspects. Mitochondrion 2021; 61:69-84. [PMID: 34592422 DOI: 10.1016/j.mito.2021.09.007] [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] [Received: 07/15/2021] [Revised: 09/03/2021] [Accepted: 09/22/2021] [Indexed: 12/29/2022]
Abstract
Mitochondrial disorders are one of the most common neurometabolic disorders affecting all age groups. The phenotype-genotype heterogeneity in these disorders can be attributed to the dual genetic control on mitochondrial functions, posing a challenge for diagnosis. Though the advancement in the high-throughput sequencing and other omics platforms resulted in a "genetics-first" approach, the muscle biopsy remains the benchmark in most of the mitochondrial disorders. This review focuses on the myopathological aspects of primary mitochondrial disorders. The utility of muscle biopsy is not limited to analyse the structural abnormalities; rather it also proves to be a potential tool to understand the deranged sub-cellular functions.
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Affiliation(s)
- Narayanappa Gayathri
- Department of Neuropathology, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore 560 029, India.
| | - Sekar Deepha
- Department of Neuropathology, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore 560 029, India
| | - Shivani Sharma
- Department of Neuropathology, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore 560 029, India
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Menger KE, Rodríguez-Luis A, Chapman J, Nicholls TJ. Controlling the topology of mammalian mitochondrial DNA. Open Biol 2021; 11:210168. [PMID: 34547213 PMCID: PMC8455175 DOI: 10.1098/rsob.210168] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The genome of mitochondria, called mtDNA, is a small circular DNA molecule present at thousands of copies per human cell. MtDNA is packaged into nucleoprotein complexes called nucleoids, and the density of mtDNA packaging affects mitochondrial gene expression. Genetic processes such as transcription, DNA replication and DNA packaging alter DNA topology, and these topological problems are solved by a family of enzymes called topoisomerases. Within mitochondria, topoisomerases are involved firstly in the regulation of mtDNA supercoiling and secondly in disentangling interlinked mtDNA molecules following mtDNA replication. The loss of mitochondrial topoisomerase activity leads to defects in mitochondrial function, and variants in the dual-localized type IA topoisomerase TOP3A have also been reported to cause human mitochondrial disease. We review the current knowledge on processes that alter mtDNA topology, how mtDNA topology is modulated by the action of topoisomerases, and the consequences of altered mtDNA topology for mitochondrial function and human health.
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Affiliation(s)
- Katja E. Menger
- Wellcome Centre for Mitochondrial Research, Biosciences Institute, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
| | - Alejandro Rodríguez-Luis
- Wellcome Centre for Mitochondrial Research, Biosciences Institute, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
| | - James Chapman
- Wellcome Centre for Mitochondrial Research, Biosciences Institute, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
| | - Thomas J. Nicholls
- Wellcome Centre for Mitochondrial Research, Biosciences Institute, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
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Ramón J, Vila-Julià F, Molina-Granada D, Molina-Berenguer M, Melià MJ, García-Arumí E, Torres-Torronteras J, Cámara Y, Martí R. Therapy Prospects for Mitochondrial DNA Maintenance Disorders. Int J Mol Sci 2021; 22:6447. [PMID: 34208592 PMCID: PMC8234938 DOI: 10.3390/ijms22126447] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Revised: 06/10/2021] [Accepted: 06/11/2021] [Indexed: 02/07/2023] Open
Abstract
Mitochondrial DNA depletion and multiple deletions syndromes (MDDS) constitute a group of mitochondrial diseases defined by dysfunctional mitochondrial DNA (mtDNA) replication and maintenance. As is the case for many other mitochondrial diseases, the options for the treatment of these disorders are rather limited today. Some aggressive treatments such as liver transplantation or allogeneic stem cell transplantation are among the few available options for patients with some forms of MDDS. However, in recent years, significant advances in our knowledge of the biochemical pathomechanisms accounting for dysfunctional mtDNA replication have been achieved, which has opened new prospects for the treatment of these often fatal diseases. Current strategies under investigation to treat MDDS range from small molecule substrate enhancement approaches to more complex treatments, such as lentiviral or adenoassociated vector-mediated gene therapy. Some of these experimental therapies have already reached the clinical phase with very promising results, however, they are hampered by the fact that these are all rare disorders and so the patient recruitment potential for clinical trials is very limited.
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Affiliation(s)
- Javier Ramón
- Research Group on Neuromuscular and Mitochondrial Diseases, Vall d’Hebron Research Institute, Universitat Autònoma de Barcelona, 08035 Barcelona, Spain; (J.R.); (F.V.-J.); (D.M.-G.); (M.M.-B.); (M.J.M.); (E.G.-A.); (J.T.-T.); (Y.C.)
- Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Ferran Vila-Julià
- Research Group on Neuromuscular and Mitochondrial Diseases, Vall d’Hebron Research Institute, Universitat Autònoma de Barcelona, 08035 Barcelona, Spain; (J.R.); (F.V.-J.); (D.M.-G.); (M.M.-B.); (M.J.M.); (E.G.-A.); (J.T.-T.); (Y.C.)
- Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - David Molina-Granada
- Research Group on Neuromuscular and Mitochondrial Diseases, Vall d’Hebron Research Institute, Universitat Autònoma de Barcelona, 08035 Barcelona, Spain; (J.R.); (F.V.-J.); (D.M.-G.); (M.M.-B.); (M.J.M.); (E.G.-A.); (J.T.-T.); (Y.C.)
- Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Miguel Molina-Berenguer
- Research Group on Neuromuscular and Mitochondrial Diseases, Vall d’Hebron Research Institute, Universitat Autònoma de Barcelona, 08035 Barcelona, Spain; (J.R.); (F.V.-J.); (D.M.-G.); (M.M.-B.); (M.J.M.); (E.G.-A.); (J.T.-T.); (Y.C.)
- Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Maria Jesús Melià
- Research Group on Neuromuscular and Mitochondrial Diseases, Vall d’Hebron Research Institute, Universitat Autònoma de Barcelona, 08035 Barcelona, Spain; (J.R.); (F.V.-J.); (D.M.-G.); (M.M.-B.); (M.J.M.); (E.G.-A.); (J.T.-T.); (Y.C.)
- Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Elena García-Arumí
- Research Group on Neuromuscular and Mitochondrial Diseases, Vall d’Hebron Research Institute, Universitat Autònoma de Barcelona, 08035 Barcelona, Spain; (J.R.); (F.V.-J.); (D.M.-G.); (M.M.-B.); (M.J.M.); (E.G.-A.); (J.T.-T.); (Y.C.)
- Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Javier Torres-Torronteras
- Research Group on Neuromuscular and Mitochondrial Diseases, Vall d’Hebron Research Institute, Universitat Autònoma de Barcelona, 08035 Barcelona, Spain; (J.R.); (F.V.-J.); (D.M.-G.); (M.M.-B.); (M.J.M.); (E.G.-A.); (J.T.-T.); (Y.C.)
- Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Yolanda Cámara
- Research Group on Neuromuscular and Mitochondrial Diseases, Vall d’Hebron Research Institute, Universitat Autònoma de Barcelona, 08035 Barcelona, Spain; (J.R.); (F.V.-J.); (D.M.-G.); (M.M.-B.); (M.J.M.); (E.G.-A.); (J.T.-T.); (Y.C.)
- Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Ramon Martí
- Research Group on Neuromuscular and Mitochondrial Diseases, Vall d’Hebron Research Institute, Universitat Autònoma de Barcelona, 08035 Barcelona, Spain; (J.R.); (F.V.-J.); (D.M.-G.); (M.M.-B.); (M.J.M.); (E.G.-A.); (J.T.-T.); (Y.C.)
- Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
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Abstract
Mitochondria are organelles with vital functions in almost all eukaryotic cells. Often described as the cellular 'powerhouses' due to their essential role in aerobic oxidative phosphorylation, mitochondria perform many other essential functions beyond energy production. As signaling organelles, mitochondria communicate with the nucleus and other organelles to help maintain cellular homeostasis, allow cellular adaptation to diverse stresses, and help steer cell fate decisions during development. Mitochondria have taken center stage in the research of normal and pathological processes, including normal tissue homeostasis and metabolism, neurodegeneration, immunity and infectious diseases. The central role that mitochondria assume within cells is evidenced by the broad impact of mitochondrial diseases, caused by defects in either mitochondrial or nuclear genes encoding for mitochondrial proteins, on different organ systems. In this Review, we will provide the reader with a foundation of the mitochondrial 'hardware', the mitochondrion itself, with its specific dynamics, quality control mechanisms and cross-organelle communication, including its roles as a driver of an innate immune response, all with a focus on development, disease and aging. We will further discuss how mitochondrial DNA is inherited, how its mutation affects cell and organismal fitness, and current therapeutic approaches for mitochondrial diseases in both model organisms and humans.
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Affiliation(s)
- Marlies P. Rossmann
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 01238, USA
- Stem Cell Program and Division of Hematology/Oncology, Boston Children's Hospital, Harvard Medical School, Howard Hughes Medical Institute, Boston, MA 02115, USA
| | - Sonia M. Dubois
- Division of Hematology/Oncology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Suneet Agarwal
- Division of Hematology/Oncology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Leonard I. Zon
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 01238, USA
- Stem Cell Program and Division of Hematology/Oncology, Boston Children's Hospital, Harvard Medical School, Howard Hughes Medical Institute, Boston, MA 02115, USA
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Jang YH, Ahn SR, Shim JY, Lim KI. Engineering Genetic Systems for Treating Mitochondrial Diseases. Pharmaceutics 2021; 13:810. [PMID: 34071708 PMCID: PMC8227772 DOI: 10.3390/pharmaceutics13060810] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 05/23/2021] [Accepted: 05/24/2021] [Indexed: 12/13/2022] Open
Abstract
Mitochondria are intracellular energy generators involved in various cellular processes. Therefore, mitochondrial dysfunction often leads to multiple serious diseases, including neurodegenerative and cardiovascular diseases. A better understanding of the underlying mitochondrial dysfunctions of the molecular mechanism will provide important hints on how to mitigate the symptoms of mitochondrial diseases and eventually cure them. In this review, we first summarize the key parts of the genetic processes that control the physiology and functions of mitochondria and discuss how alterations of the processes cause mitochondrial diseases. We then list up the relevant core genetic components involved in these processes and explore the mutations of the components that link to the diseases. Lastly, we discuss recent attempts to apply multiple genetic methods to alleviate and further reverse the adverse effects of the core component mutations on the physiology and functions of mitochondria.
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Affiliation(s)
- Yoon-ha Jang
- Department of Chemical and Biological Engineering, Sookmyung Women’s University, Yongsan-gu, Seoul 04310, Korea; (Y.-h.J.); (J.-y.S.)
| | - Sae Ryun Ahn
- Industry Collaboration Center, Industry-Academic Cooperation Foundation, Sookmyung Women’s University, Yongsan-gu, Seoul 04310, Korea;
| | - Ji-yeon Shim
- Department of Chemical and Biological Engineering, Sookmyung Women’s University, Yongsan-gu, Seoul 04310, Korea; (Y.-h.J.); (J.-y.S.)
| | - Kwang-il Lim
- Department of Chemical and Biological Engineering, Sookmyung Women’s University, Yongsan-gu, Seoul 04310, Korea; (Y.-h.J.); (J.-y.S.)
- Industry Collaboration Center, Industry-Academic Cooperation Foundation, Sookmyung Women’s University, Yongsan-gu, Seoul 04310, Korea;
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Bonora E, Chakrabarty S, Kellaris G, Tsutsumi M, Bianco F, Bergamini C, Ullah F, Isidori F, Liparulo I, Diquigiovanni C, Masin L, Rizzardi N, Cratere MG, Boschetti E, Papa V, Maresca A, Cenacchi G, Casadio R, Martelli P, Matera I, Ceccherini I, Fato R, Raiola G, Arrigo S, Signa S, Sementa AR, Severino M, Striano P, Fiorillo C, Goto T, Uchino S, Oyazato Y, Nakamura H, Mishra SK, Yeh YS, Kato T, Nozu K, Tanboon J, Morioka I, Nishino I, Toda T, Goto YI, Ohtake A, Kosaki K, Yamaguchi Y, Nonaka I, Iijima K, Mimaki M, Kurahashi H, Raams A, MacInnes A, Alders M, Engelen M, Linthorst G, de Koning T, den Dunnen W, Dijkstra G, van Spaendonck K, van Gent DC, Aronica EM, Picco P, Carelli V, Seri M, Katsanis N, Duijkers FAM, Taniguchi-Ikeda M, De Giorgio R. Biallelic variants in LIG3 cause a novel mitochondrial neurogastrointestinal encephalomyopathy. Brain 2021; 144:1451-1466. [PMID: 33855352 DOI: 10.1093/brain/awab056] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Revised: 11/13/2020] [Accepted: 12/09/2020] [Indexed: 12/11/2022] Open
Abstract
Abnormal gut motility is a feature of several mitochondrial encephalomyopathies, and mutations in genes such as TYMP and POLG, have been linked to these rare diseases. The human genome encodes three DNA ligases, of which only one, ligase III (LIG3), has a mitochondrial splice variant and is crucial for mitochondrial health. We investigated the effect of reduced LIG3 activity and resulting mitochondrial dysfunction in seven patients from three independent families, who showed the common occurrence of gut dysmotility and neurological manifestations reminiscent of mitochondrial neurogastrointestinal encephalomyopathy. DNA from these patients was subjected to whole exome sequencing. In all patients, compound heterozygous variants in a new disease gene, LIG3, were identified. All variants were predicted to have a damaging effect on the protein. The LIG3 gene encodes the only mitochondrial DNA (mtDNA) ligase and therefore plays a pivotal role in mtDNA repair and replication. In vitro assays in patient-derived cells showed a decrease in LIG3 protein levels and ligase activity. We demonstrated that the LIG3 gene defects affect mtDNA maintenance, leading to mtDNA depletion without the accumulation of multiple deletions as observed in other mitochondrial disorders. This mitochondrial dysfunction is likely to cause the phenotypes observed in these patients. The most prominent and consistent clinical signs were severe gut dysmotility and neurological abnormalities, including leukoencephalopathy, epilepsy, migraine, stroke-like episodes, and neurogenic bladder. A decrease in the number of myenteric neurons, and increased fibrosis and elastin levels were the most prominent changes in the gut. Cytochrome c oxidase (COX) deficient fibres in skeletal muscle were also observed. Disruption of lig3 in zebrafish reproduced the brain alterations and impaired gut transit in vivo. In conclusion, we identified variants in the LIG3 gene that result in a mitochondrial disease characterized by predominant gut dysmotility, encephalopathy, and neuromuscular abnormalities.
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Affiliation(s)
- Elena Bonora
- Department of Medical and Surgical Sciences, St. Orsola-Malpighi Hospital, University of Bologna, Bologna, 40138, Italy
| | - Sanjiban Chakrabarty
- Department of Molecular Genetics, Erasmus MC, Rotterdam, 3000 CA, The Netherlands
| | - Georgios Kellaris
- Center for Human Disease Modeling, Duke University, Durham, NC 27710, USA
| | - Makiko Tsutsumi
- Division of Molecular Genetics, Institute for Comprehensive Medical Science, Fujita Health University, Aichi, 470-1192, Japan
| | - Francesca Bianco
- Department of Medical and Surgical Sciences, St. Orsola-Malpighi Hospital, University of Bologna, Bologna, 40138, Italy
| | - Christian Bergamini
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna, 40126, Italy
| | - Farid Ullah
- Center for Human Disease Modeling, Duke University, Durham, NC 27710, USA
| | - Federica Isidori
- Department of Medical and Surgical Sciences, St. Orsola-Malpighi Hospital, University of Bologna, Bologna, 40138, Italy
| | - Irene Liparulo
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna, 40126, Italy
| | - Chiara Diquigiovanni
- Department of Medical and Surgical Sciences, St. Orsola-Malpighi Hospital, University of Bologna, Bologna, 40138, Italy
| | - Luca Masin
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna, 40126, Italy
| | - Nicola Rizzardi
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna, 40126, Italy
| | - Mariapia Giuditta Cratere
- Department of Medical and Surgical Sciences, St. Orsola-Malpighi Hospital, University of Bologna, Bologna, 40138, Italy.,Division of Genetics and Cell Biology, San Raffaele Scientific Institute, Milan, 20132, Italy
| | - Elisa Boschetti
- Department of Medical and Surgical Sciences, St. Orsola-Malpighi Hospital, University of Bologna, Bologna, 40138, Italy
| | - Valentina Papa
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, 40123, Italy
| | - Alessandra Maresca
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Programma di Neurogenetica, Bologna, 40139, Italy
| | - Giovanna Cenacchi
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, 40123, Italy
| | - Rita Casadio
- Biocomputing Group, Department of Biological, Geological, Environmental Sciences, University of Bologna, Bologna, 40126, Italy
| | - Pierluigi Martelli
- Biocomputing Group, Department of Biological, Geological, Environmental Sciences, University of Bologna, Bologna, 40126, Italy
| | - Ivana Matera
- IRCCS Istituto Giannina Gaslini, Genova, 16128, Italy
| | | | - Romana Fato
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna, 40126, Italy
| | - Giuseppe Raiola
- Department of Paediatrics, Pugliese-Ciaccio Hospital, Catanzaro, 88100, Italy
| | - Serena Arrigo
- IRCCS Istituto Giannina Gaslini, Genova, 16128, Italy
| | - Sara Signa
- IRCCS Istituto Giannina Gaslini, Genova, 16128, Italy
| | | | | | | | | | - Tsuyoshi Goto
- Laboratory of Molecular Function of Food, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, 611-0011, Japan
| | - Shumpei Uchino
- Department of Pediatrics, Teikyo University School of Medicine, Tokyo, 173-8605, Japan.,Department of Pediatrics, Graduate School of Medicine, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Yoshinobu Oyazato
- Department of Pediatrics, Kakogawa Central City Hospital, Kakogawa, Hyogo, 675-8611, Japan
| | - Hisayoshi Nakamura
- Department of Neuromuscular Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, 187-8502, Japan
| | - Sushil K Mishra
- Glycoscience Group, National University of Ireland, Galway, H91 CF50, Ireland
| | - Yu-Sheng Yeh
- Laboratory of Molecular Function of Food, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, 611-0011, Japan
| | - Takema Kato
- Division of Molecular Genetics, Institute for Comprehensive Medical Science, Fujita Health University, Aichi, 470-1192, Japan
| | - Kandai Nozu
- Department of Pediatrics, Kobe University Graduate School of Medicine, Hyogo, 650-0017, Japan
| | - Jantima Tanboon
- Department of Neuromuscular Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, 187-8502, Japan
| | - Ichiro Morioka
- Department of Pediatrics and Child Health, Nihon University School of Medicine, Tokyo, 173-8610, Japan
| | - Ichizo Nishino
- Department of Neuromuscular Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, 187-8502, Japan
| | - Tatsushi Toda
- Department of Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Yu-Ichi Goto
- Department of Mental Retardation and Birth Defect Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, 187-8502, Japan
| | - Akira Ohtake
- Department of Pediatrics & Clinical Genomics, Faculty of Medicine, Saitama Medical University, Saitama, 350-0495, Japan
| | - Kenjiro Kosaki
- Center for Medical Genetics, Keio University School of Medicine, Tokyo, 160-8582, Japan
| | - Yoshiki Yamaguchi
- Laboratory of Pharmaceutical Physical Chemistry, Tohoku Medical and Pharmaceutical University, Miyagi, 981-8558, Japan
| | - Ikuya Nonaka
- Department of Neuromuscular Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, 187-8502, Japan
| | - Kazumoto Iijima
- Department of Pediatrics, Kobe University Graduate School of Medicine, Hyogo, 650-0017, Japan
| | - Masakazu Mimaki
- Department of Pediatrics, Teikyo University School of Medicine, Tokyo, 173-8605, Japan
| | - Hiroki Kurahashi
- Division of Molecular Genetics, Institute for Comprehensive Medical Science, Fujita Health University, Aichi, 470-1192, Japan
| | - Anja Raams
- Department of Molecular Genetics, Erasmus MC, Rotterdam, 3000 CA, The Netherlands
| | - Alyson MacInnes
- Department of Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Amsterdam, 1100 DD, The Netherlands
| | - Mariel Alders
- Department of Clinical Genetics, Amsterdam UMC, University of Amsterdam, Amsterdam, 1100 DD, The Netherlands
| | - Marc Engelen
- Department of Neurology, Amsterdam UMC, University of Amsterdam, Amsterdam, 1100 DD, The Netherlands
| | - Gabor Linthorst
- Department of Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Amsterdam, 1100 DD, The Netherlands
| | - Tom de Koning
- Department of Metabolic Diseases, UMCG, Groningen, 9700 RB, The Netherlands
| | | | - Gerard Dijkstra
- Department of Gastroenterology, UMCG, Groningen, 9700 RB, The Netherlands
| | - Karin van Spaendonck
- Department of Clinical Genetics, Amsterdam UMC, University of Amsterdam, Amsterdam, 1100 DD, The Netherlands
| | - Dik C van Gent
- Department of Molecular Genetics, Erasmus MC, Rotterdam, 3000 CA, The Netherlands
| | - Eleonora M Aronica
- Department of Pathology, Amsterdam UMC, University of Amsterdam, Amsterdam, 1100 DD, The Netherlands
| | - Paolo Picco
- IRCCS Istituto Giannina Gaslini, Genova, 16128, Italy
| | - Valerio Carelli
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, 40123, Italy.,IRCCS Istituto delle Scienze Neurologiche di Bologna, Programma di Neurogenetica, Bologna, 40139, Italy
| | - Marco Seri
- Department of Medical and Surgical Sciences, St. Orsola-Malpighi Hospital, University of Bologna, Bologna, 40138, Italy
| | - Nicholas Katsanis
- Center for Human Disease Modeling, Duke University, Durham, NC 27710, USA
| | - Floor A M Duijkers
- Department of Clinical Genetics, Amsterdam UMC, University of Amsterdam, Amsterdam, 1100 DD, The Netherlands
| | - Mariko Taniguchi-Ikeda
- Division of Molecular Genetics, Institute for Comprehensive Medical Science, Fujita Health University, Aichi, 470-1192, Japan.,Department of Pediatrics, Kobe University Graduate School of Medicine, Hyogo, 650-0017, Japan.,Department of Clinical Genetics, Fujita Health University Hospital, Aichi, 470-1192, Japan
| | - Roberto De Giorgio
- Department of Morphology, Surgery and Experimental Medicine, St. Anna Hospital, University of Ferrara, Ferrara, 44124, Italy
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Mitochondrial genome stability in human: understanding the role of DNA repair pathways. Biochem J 2021; 478:1179-1197. [DOI: 10.1042/bcj20200920] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 02/15/2021] [Accepted: 02/17/2021] [Indexed: 11/17/2022]
Abstract
Mitochondria are semiautonomous organelles in eukaryotic cells and possess their own genome that replicates independently. Mitochondria play a major role in oxidative phosphorylation due to which its genome is frequently exposed to oxidative stress. Factors including ionizing radiation, radiomimetic drugs and replication fork stalling can also result in different types of mutations in mitochondrial DNA (mtDNA) leading to genome fragility. Mitochondria from myopathies, dystonia, cancer patient samples show frequent mtDNA mutations such as point mutations, insertions and large-scale deletions that could account for mitochondria-associated disease pathogenesis. The mechanism by which such mutations arise following exposure to various DNA-damaging agents is not well understood. One of the well-studied repair pathways in mitochondria is base excision repair. Other repair pathways such as mismatch repair, homologous recombination and microhomology-mediated end joining have also been reported. Interestingly, nucleotide excision repair and classical nonhomologous DNA end joining are not detected in mitochondria. In this review, we summarize the potential causes of mitochondrial genome fragility, their implications as well as various DNA repair pathways that operate in mitochondria.
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Jacinto S, Guerreiro P, de Oliveira RM, Cunha-Oliveira T, Santos MJ, Grazina M, Rego AC, Outeiro TF. MPV17 Mutations Are Associated With a Quiescent Energetic Metabolic Profile. Front Cell Neurosci 2021; 15:641264. [PMID: 33815063 PMCID: PMC8011494 DOI: 10.3389/fncel.2021.641264] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Accepted: 02/08/2021] [Indexed: 02/03/2023] Open
Abstract
Mutations in the MPV17 gene are associated with hepatocerebral form of mitochondrial depletion syndrome. The mechanisms through which MPV17 mutations cause respiratory chain dysfunction and mtDNA depletion is still unclear. The MPV17 gene encodes an inner membrane mitochondrial protein that was recently described to function as a non-selective channel. Although its exact function is unknown, it is thought to be important in the maintenance of mitochondrial membrane potential (ΔΨm). To obtain more information about the role of MPV17 in human disease, we investigated the effect of MPV17 knockdown and of selected known MPV17 mutations associated with MPV17 disease in vitro. We used different approaches in order to evaluate the cellular consequences of MPV17 deficiency. We found that lower levels of MPV17 were associated with impaired mitochondrial respiration and with a quiescent energetic metabolic profile. All the mutations studied destabilized the protein, resulting in reduced protein levels. We also demonstrated that different mutations caused different cellular abnormalities, including increased ROS production, decreased oxygen consumption, loss of ΔΨm, and mislocalization of MPV17 protein. Our study provides novel insight into the molecular effects of MPV17 mutations and opens novel possibilities for testing therapeutic strategies for a devastating group of disorders.
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Affiliation(s)
- Sandra Jacinto
- Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal.,Serviço de Neurologia Pediátrica, Hospital Dona Estefânia, Centro Hospitalar Universitário Lisboa Central-EPE, Lisboa, Portugal
| | - Patrícia Guerreiro
- Department of Experimental Neurodegeneration, Center for Biostructural Imaging of Neurodegeneration, University Medical Center Göttingen, Göttingen, Germany.,Switch Laboratory, Center for Brain and Disease Research, Vlaams Instituut voor Biotechnologie (VIB), Leuven, Belgium.,Switch Laboratory, Department of Cellular and Molecular Medicine, Katholiek Universiteit (KU), Leuven, Belgium
| | - Rita Machado de Oliveira
- CEDOC - Chronic Diseases Research Center, Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisboa, Portugal
| | | | - Maria João Santos
- Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,Faculty of Medicine, University of Coimbra, Coimbra, Portugal.,CIBB - Center for Innovative Biomedicine and Biotechnology, University of Coimbra, Portugal
| | - Manuela Grazina
- Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,Faculty of Medicine, University of Coimbra, Coimbra, Portugal.,CIBB - Center for Innovative Biomedicine and Biotechnology, University of Coimbra, Portugal
| | - Ana Cristina Rego
- Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - Tiago F Outeiro
- Department of Experimental Neurodegeneration, Center for Biostructural Imaging of Neurodegeneration, University Medical Center Göttingen, Göttingen, Germany.,Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom.,Max Planck Institute for Experimental Medicine, Göttingen, Germany
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47
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Filograna R, Mennuni M, Alsina D, Larsson NG. Mitochondrial DNA copy number in human disease: the more the better? FEBS Lett 2020; 595:976-1002. [PMID: 33314045 PMCID: PMC8247411 DOI: 10.1002/1873-3468.14021] [Citation(s) in RCA: 209] [Impact Index Per Article: 52.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 11/02/2020] [Accepted: 11/26/2020] [Indexed: 12/19/2022]
Abstract
Most of the genetic information has been lost or transferred to the nucleus during the evolution of mitochondria. Nevertheless, mitochondria have retained their own genome that is essential for oxidative phosphorylation (OXPHOS). In mammals, a gene‐dense circular mitochondrial DNA (mtDNA) of about 16.5 kb encodes 13 proteins, which constitute only 1% of the mitochondrial proteome. Mammalian mtDNA is present in thousands of copies per cell and mutations often affect only a fraction of them. Most pathogenic human mtDNA mutations are recessive and only cause OXPHOS defects if present above a certain critical threshold. However, emerging evidence strongly suggests that the proportion of mutated mtDNA copies is not the only determinant of disease but that also the absolute copy number matters. In this review, we critically discuss current knowledge of the role of mtDNA copy number regulation in various types of human diseases, including mitochondrial disorders, neurodegenerative disorders and cancer, and during ageing. We also provide an overview of new exciting therapeutic strategies to directly manipulate mtDNA to restore OXPHOS in mitochondrial diseases.
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Affiliation(s)
- Roberta Filograna
- Division of Molecular Metabolism, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.,Max Planck Institute for Biology of Ageing - Karolinska Institutet Laboratory, Karolinska Institutet, Stockholm, Sweden
| | - Mara Mennuni
- Division of Molecular Metabolism, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.,Max Planck Institute for Biology of Ageing - Karolinska Institutet Laboratory, Karolinska Institutet, Stockholm, Sweden
| | - David Alsina
- Division of Molecular Metabolism, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.,Max Planck Institute for Biology of Ageing - Karolinska Institutet Laboratory, Karolinska Institutet, Stockholm, Sweden
| | - Nils-Göran Larsson
- Division of Molecular Metabolism, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.,Max Planck Institute for Biology of Ageing - Karolinska Institutet Laboratory, Karolinska Institutet, Stockholm, Sweden
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48
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Accurate mapping of mitochondrial DNA deletions and duplications using deep sequencing. PLoS Genet 2020; 16:e1009242. [PMID: 33315859 PMCID: PMC7769605 DOI: 10.1371/journal.pgen.1009242] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 12/28/2020] [Accepted: 11/02/2020] [Indexed: 12/21/2022] Open
Abstract
Deletions and duplications in mitochondrial DNA (mtDNA) cause mitochondrial disease and accumulate in conditions such as cancer and age-related disorders, but validated high-throughput methodology that can readily detect and discriminate between these two types of events is lacking. Here we establish a computational method, MitoSAlt, for accurate identification, quantification and visualization of mtDNA deletions and duplications from genomic sequencing data. Our method was tested on simulated sequencing reads and human patient samples with single deletions and duplications to verify its accuracy. Application to mouse models of mtDNA maintenance disease demonstrated the ability to detect deletions and duplications even at low levels of heteroplasmy.
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49
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The ubiquitin-proteasome system and its crosstalk with mitochondria as therapeutic targets in medicine. Pharmacol Res 2020; 163:105248. [PMID: 33065283 DOI: 10.1016/j.phrs.2020.105248] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 10/06/2020] [Accepted: 10/07/2020] [Indexed: 12/12/2022]
Abstract
The ubiquitin-proteasome system constitutes a major pathway for protein degradation in the cell. Therefore the crosstalk of this pathway with mitochondria is a major topic with direct relevance to many mitochondrial diseases. Proteasome dysfunction triggers not only protein toxicity, but also mitochondrial dysfunction. The involvement of proteasomes in the regulation of protein transport into mitochondria contributes to an increase in mitochondrial function defects. On the other hand, mitochondrial impairment stimulates reactive oxygen species production, which increases protein damage, and protein misfolding and aggregation leading to proteasome overload. Concurrently, mitochondrial dysfunction compromises cellular ATP production leading to reduced protein ubiquitination and proteasome activity. In this review we discuss the complex relationship and interdependence of the ubiquitin-proteasome system and mitochondria. Furthermore, we describe pharmacological inhibition of proteasome activity as a novel strategy to treat a group of mitochondrial diseases.
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50
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Saneto RP. Mitochondrial diseases: expanding the diagnosis in the era of genetic testing. JOURNAL OF TRANSLATIONAL GENETICS AND GENOMICS 2020; 4:384-428. [PMID: 33426505 PMCID: PMC7791531 DOI: 10.20517/jtgg.2020.40] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Mitochondrial diseases are clinically and genetically heterogeneous. These diseases were initially described a little over three decades ago. Limited diagnostic tools created disease descriptions based on clinical, biochemical analytes, neuroimaging, and muscle biopsy findings. This diagnostic mechanism continued to evolve detection of inherited oxidative phosphorylation disorders and expanded discovery of mitochondrial physiology over the next two decades. Limited genetic testing hampered the definitive diagnostic identification and breadth of diseases. Over the last decade, the development and incorporation of massive parallel sequencing has identified approximately 300 genes involved in mitochondrial disease. Gene testing has enlarged our understanding of how genetic defects lead to cellular dysfunction and disease. These findings have expanded the understanding of how mechanisms of mitochondrial physiology can induce dysfunction and disease, but the complete collection of disease-causing gene variants remains incomplete. This article reviews the developments in disease gene discovery and the incorporation of gene findings with mitochondrial physiology. This understanding is critical to the development of targeted therapies.
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Affiliation(s)
- Russell P. Saneto
- Center for Integrative Brain Research, Neuroscience Institute, Seattle, WA 98101, USA
- Department of Neurology/Division of Pediatric Neurology, Seattle Children’s Hospital/University of Washington, Seattle, WA 98105, USA
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