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Rua AJ, Mitchell W, Claypool SM, Alder NN, Alexandrescu AT. Perturbations in mitochondrial metabolism associated with defective cardiolipin biosynthesis: An in-organello real-time NMR study. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.18.599628. [PMID: 38948727 PMCID: PMC11212973 DOI: 10.1101/2024.06.18.599628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/02/2024]
Abstract
Mitochondria are central to cellular metabolism; hence, their dysfunction contributes to a wide array of human diseases including cancer, cardiopathy, neurodegeneration, and heritable pathologies such as Barth syndrome. Cardiolipin, the signature phospholipid of the mitochondrion promotes proper cristae morphology, bioenergetic functions, and directly affects metabolic reactions carried out in mitochondrial membranes. To match tissue-specific metabolic demands, cardiolipin typically undergoes an acyl tail remodeling process with the final step carried out by the phospholipid-lysophospholipid transacylase tafazzin. Mutations in the tafazzin gene are the primary cause of Barth syndrome. Here, we investigated how defects in cardiolipin biosynthesis and remodeling impact metabolic flux through the tricarboxylic acid cycle and associated pathways in yeast. Nuclear magnetic resonance was used to monitor in real-time the metabolic fate of 13C3-pyruvate in isolated mitochondria from three isogenic yeast strains. We compared mitochondria from a wild-type strain to mitochondria from a Δtaz1 strain that lacks tafazzin and contains lower amounts of unremodeled cardiolipin, and mitochondria from a Δcrd1 strain that lacks cardiolipin synthase and cannot synthesize cardiolipin. We found that the 13C-label from the pyruvate substrate was distributed through about twelve metabolites. Several of the identified metabolites were specific to yeast pathways, including branched chain amino acids and fusel alcohol synthesis. Most metabolites showed similar kinetics amongst the different strains but mevalonate and α-ketoglutarate, as well as the NAD+/NADH couple measured in separate nuclear magnetic resonance experiments, showed pronounced differences. Taken together, the results show that cardiolipin remodeling influences pyruvate metabolism, tricarboxylic acid cycle flux, and the levels of mitochondrial nucleotides.
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Affiliation(s)
- Antonio J. Rua
- Department of Molecular and Cellular Biology, University of Connecticut, Storrs, CT 06269, USA
| | - Wayne Mitchell
- Department of Molecular and Cellular Biology, University of Connecticut, Storrs, CT 06269, USA
| | - Steven M. Claypool
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Mitochondrial Phospholipid Research Center, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Nathan N. Alder
- Department of Molecular and Cellular Biology, University of Connecticut, Storrs, CT 06269, USA
| | - Andrei T. Alexandrescu
- Department of Molecular and Cellular Biology, University of Connecticut, Storrs, CT 06269, USA
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2
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Li T, Aziz T, Li G, Zhang L, Yao J, Jia S. A zebrafish tufm mutant model for the COXPD4 syndrome of aberrant mitochondrial function. J Genet Genomics 2024:S1673-8527(24)00122-X. [PMID: 38825039 DOI: 10.1016/j.jgg.2024.05.009] [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: 04/08/2024] [Revised: 05/23/2024] [Accepted: 05/25/2024] [Indexed: 06/04/2024]
Abstract
Mitochondrial dysfunction is a critical factor leading to a wide range of clinically heterogeneous and often severe disorders due to its central role in generating cellular energy. Mutations in the TUFM gene are known to cause combined oxidative phosphorylation deficiency 4 (COXPD4), a rare mitochondrial disorder characterized by a comprehensive quantitative deficiency in mitochondrial respiratory chain (MRC) complexes. The development of a reliable animal model for COXPD4 is crucial for elucidating the roles and mechanisms of TUFM in disease pathogenesis and benefiting its medical management. In this study, we construct a zebrafish tufm-/- mutant that closely resembles the COXPD4 syndrome, exhibiting compromised mitochondrial protein translation, dysfunctional mitochondria with oxidative phosphorylation (OXPHOS) defects, and significant metabolic suppression of the tricarboxylic acid (TCA) cycle. Leveraging this COXPD4 zebrafish model, we comprehensively validate the clinical relevance of TUFM mutations and identify probucol as a promising therapeutic approach for managing COXPD4. Our data offer valuable insights for understanding mitochondrial diseases and developing effective treatments.
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Affiliation(s)
- Ting Li
- School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Tursunjan Aziz
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Guangyuan Li
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Lin Zhang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Jihua Yao
- School of Life Sciences, Fudan University, Shanghai 200438, China.
| | - Shunji Jia
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
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3
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Burr SP, Chinnery PF. Origins of tissue and cell-type specificity in mitochondrial DNA (mtDNA) disease. Hum Mol Genet 2024; 33:R3-R11. [PMID: 38779777 PMCID: PMC11112380 DOI: 10.1093/hmg/ddae059] [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: 12/21/2023] [Revised: 12/21/2023] [Accepted: 02/05/2024] [Indexed: 05/25/2024] Open
Abstract
Mutations of mitochondrial (mt)DNA are a major cause of morbidity and mortality in humans, accounting for approximately two thirds of diagnosed mitochondrial disease. However, despite significant advances in technology since the discovery of the first disease-causing mtDNA mutations in 1988, the comprehensive diagnosis and treatment of mtDNA disease remains challenging. This is partly due to the highly variable clinical presentation linked to tissue-specific vulnerability that determines which organs are affected. Organ involvement can vary between different mtDNA mutations, and also between patients carrying the same disease-causing variant. The clinical features frequently overlap with other non-mitochondrial diseases, both rare and common, adding to the diagnostic challenge. Building on previous findings, recent technological advances have cast further light on the mechanisms which underpin the organ vulnerability in mtDNA diseases, but our understanding is far from complete. In this review we explore the origins, current knowledge, and future directions of research in this area.
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Affiliation(s)
- Stephen P Burr
- Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus, Hills Road, Cambridge, CB2 0QQ, United Kingdom
| | - Patrick F Chinnery
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge, CB2 0XY, United Kingdom
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Neuhofer CM, Prokisch H. Digenic Inheritance in Rare Disorders and Mitochondrial Disease-Crossing the Frontier to a More Comprehensive Understanding of Etiology. Int J Mol Sci 2024; 25:4602. [PMID: 38731822 PMCID: PMC11083678 DOI: 10.3390/ijms25094602] [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: 02/13/2024] [Revised: 04/10/2024] [Accepted: 04/12/2024] [Indexed: 05/13/2024] Open
Abstract
Our understanding of rare disease genetics has been shaped by a monogenic disease model. While the traditional monogenic disease model has been successful in identifying numerous disease-associated genes and significantly enlarged our knowledge in the field of human genetics, it has limitations in explaining phenomena like phenotypic variability and reduced penetrance. Widening the perspective beyond Mendelian inheritance has the potential to enable a better understanding of disease complexity in rare disorders. Digenic inheritance is the simplest instance of a non-Mendelian disorder, characterized by the functional interplay of variants in two disease-contributing genes. Known digenic disease causes show a range of pathomechanisms underlying digenic interplay, including direct and indirect gene product interactions as well as epigenetic modifications. This review aims to systematically explore the background of digenic inheritance in rare disorders, the approaches and challenges when investigating digenic inheritance, and the current evidence for digenic inheritance in mitochondrial disorders.
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Affiliation(s)
- Christiane M. Neuhofer
- Institute of Human Genetics, University Medical Center, Technical University of Munich, Trogerstr. 32, 81675 Munich, Germany
- Institute of Neurogenomics, Computational Health Center, Helmholtz Centre Munich Neuherberg, Ingolstädter Landstraße 1, 85764 Oberschleißheim, Germany
- Institute of Human Genetics, Salzburger Landeskliniken, University Hospital of the Paracelsus Medical University, Müllner Hauptstraße 48, 5020 Salzburg, Austria
| | - Holger Prokisch
- Institute of Human Genetics, University Medical Center, Technical University of Munich, Trogerstr. 32, 81675 Munich, Germany
- Institute of Neurogenomics, Computational Health Center, Helmholtz Centre Munich Neuherberg, Ingolstädter Landstraße 1, 85764 Oberschleißheim, Germany
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Misceo D, Strømme P, Bitarafan F, Chawla MS, Sheng Y, Bach de Courtade SM, Eide L, Frengen E. Biallelic NDUFA4 Deletion Causes Mitochondrial Complex IV Deficiency in a Patient with Leigh Syndrome. Genes (Basel) 2024; 15:500. [PMID: 38674434 PMCID: PMC11050323 DOI: 10.3390/genes15040500] [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: 03/27/2024] [Revised: 04/13/2024] [Accepted: 04/15/2024] [Indexed: 04/28/2024] Open
Abstract
Oxidative phosphorylation involves a complex multi-enzymatic mitochondrial machinery critical for proper functioning of the cell, and defects herein cause a wide range of diseases called "primary mitochondrial disorders" (PMDs). Mutations in about 400 nuclear and 37 mitochondrial genes have been documented to cause PMDs, which have an estimated birth prevalence of 1:5000. Here, we describe a 4-year-old female presenting from early childhood with psychomotor delay and white matter signal changes affecting several brain regions, including the brainstem, in addition to lactic and phytanic acidosis, compatible with Leigh syndrome, a genetically heterogeneous subgroup of PMDs. Whole genome sequencing of the family trio identified a homozygous 12.9 Kb deletion, entirely overlapping the NDUFA4 gene. Sanger sequencing of the breakpoints revealed that the genomic rearrangement was likely triggered by Alu elements flanking the gene. NDUFA4 encodes for a subunit of the respiratory chain Complex IV, whose activity was significantly reduced in the patient's fibroblasts. In one family, dysfunction of NDUFA4 was previously documented as causing mitochondrial Complex IV deficiency nuclear type 21 (MC4DN21, OMIM 619065), a relatively mild form of Leigh syndrome. Our finding confirms the loss of NDUFA4 function as an ultra-rare cause of Complex IV defect, clinically presenting as Leigh syndrome.
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Affiliation(s)
- Doriana Misceo
- Department of Medical Genetics, Oslo University Hospital and University of Oslo, 0450 Oslo, Norway; (F.B.); (Y.S.); (E.F.)
| | - Petter Strømme
- Division of Pediatrics and Adolescent Medicine, Oslo University Hospital and Faculty of Medicine, University of Oslo, 0450 Oslo, Norway;
| | - Fatemeh Bitarafan
- Department of Medical Genetics, Oslo University Hospital and University of Oslo, 0450 Oslo, Norway; (F.B.); (Y.S.); (E.F.)
| | | | - Ying Sheng
- Department of Medical Genetics, Oslo University Hospital and University of Oslo, 0450 Oslo, Norway; (F.B.); (Y.S.); (E.F.)
| | | | - Lars Eide
- Department of Biochemistry, Oslo University Hospital and University of Oslo, 0450 Oslo, Norway; (S.M.B.d.C.); (L.E.)
| | - Eirik Frengen
- Department of Medical Genetics, Oslo University Hospital and University of Oslo, 0450 Oslo, Norway; (F.B.); (Y.S.); (E.F.)
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Nogueira C, Pereira C, Silva L, Laranjeira M, Lopes A, Neiva R, Rodrigues E, Campos T, Martins E, Bandeira A, Coelho M, Magalhães M, Damásio J, Gaspar A, Janeiro P, Gomes AL, Ferreira AC, Jacinto S, Vieira JP, Diogo L, Santos H, Mendonça C, Vilarinho L. The genetic landscape of mitochondrial diseases in the next-generation sequencing era: a Portuguese cohort study. Front Cell Dev Biol 2024; 12:1331351. [PMID: 38465286 PMCID: PMC10920333 DOI: 10.3389/fcell.2024.1331351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 01/30/2024] [Indexed: 03/12/2024] Open
Abstract
Introduction: Rare disorders that are genetically and clinically heterogeneous, such as mitochondrial diseases (MDs), have a challenging diagnosis. Nuclear genes codify most proteins involved in mitochondrial biogenesis, despite all mitochondria having their own DNA. The development of next-generation sequencing (NGS) technologies has revolutionized the understanding of many genes involved in the pathogenesis of MDs. In this new genetic era, using the NGS approach, we aimed to identify the genetic etiology for a suspected MD in a cohort of 450 Portuguese patients. Methods: We examined 450 patients using a combined NGS strategy, starting with the analysis of a targeted mitochondrial panel of 213 nuclear genes, and then proceeding to analyze the whole mitochondrial DNA. Results and Discussion: In this study, we identified disease-related variants in 134 (30%) analyzed patients, 88 with nuclear DNA (nDNA) and 46 with mitochondrial DNA (mtDNA) variants, most of them being pediatric patients (66%), of which 77% were identified in nDNA and 23% in mtDNA. The molecular analysis of this cohort revealed 72 already described pathogenic and 20 novel, probably pathogenic, variants, as well as 62 variants of unknown significance. For this cohort of patients with suspected MDs, the use of a customized gene panel provided a molecular diagnosis in a timely and cost-effective manner. Patients who cannot be diagnosed after this initial approach will be further selected for whole-exome sequencing. Conclusion: As a national laboratory for the study and research of MDs, we demonstrated the power of NGS to achieve a molecular etiology, expanding the mutational spectrum and proposing accurate genetic counseling in this group of heterogeneous diseases without therapeutic options.
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Affiliation(s)
- C. Nogueira
- Research & Development Unit, Human Genetics Department, National Institute of Health Doutor Ricardo Jorge, Lisbon, Portugal
- Newborn Screening, Metabolism & Genetics Unit, Human Genetics Department, National Institute of Health Doutor Ricardo Jorge, Lisbon, Portugal
| | - C. Pereira
- Newborn Screening, Metabolism & Genetics Unit, Human Genetics Department, National Institute of Health Doutor Ricardo Jorge, Lisbon, Portugal
| | - L. Silva
- Research & Development Unit, Human Genetics Department, National Institute of Health Doutor Ricardo Jorge, Lisbon, Portugal
- Newborn Screening, Metabolism & Genetics Unit, Human Genetics Department, National Institute of Health Doutor Ricardo Jorge, Lisbon, Portugal
| | - Mateus Laranjeira
- Research & Development Unit, Human Genetics Department, National Institute of Health Doutor Ricardo Jorge, Lisbon, Portugal
| | - A. Lopes
- Newborn Screening, Metabolism & Genetics Unit, Human Genetics Department, National Institute of Health Doutor Ricardo Jorge, Lisbon, Portugal
| | - R. Neiva
- Newborn Screening, Metabolism & Genetics Unit, Human Genetics Department, National Institute of Health Doutor Ricardo Jorge, Lisbon, Portugal
| | - E. Rodrigues
- Inherited Metabolic Diseases Reference Centre, São João Hospital University Centre, Porto, Portugal
| | - T. Campos
- Inherited Metabolic Diseases Reference Centre, São João Hospital University Centre, Porto, Portugal
| | - E. Martins
- Inherited Metabolic Diseases Reference Centre, Santo António Hospital University Centre, Porto, Portugal
| | - A. Bandeira
- Inherited Metabolic Diseases Reference Centre, Santo António Hospital University Centre, Porto, Portugal
| | - M. Coelho
- Inherited Metabolic Diseases Reference Centre, Santo António Hospital University Centre, Porto, Portugal
| | - M. Magalhães
- Neurology Department, Santo António Hospital University Centre, Porto, Portugal
| | - J. Damásio
- Neurology Department, Santo António Hospital University Centre, Porto, Portugal
| | - A. Gaspar
- Inherited Metabolic Diseases Reference Centre, Lisboa Norte Hospital University Centre, Lisboa, Portugal
| | - P Janeiro
- Inherited Metabolic Diseases Reference Centre, Lisboa Norte Hospital University Centre, Lisboa, Portugal
| | - A. Levy Gomes
- Neurology Department, Lisboa Norte Hospital University Centre, Lisboa, Portugal
| | - A. C. Ferreira
- Inherited Metabolic Diseases Reference Centre, Lisboa Central Hospital Centre, Lisboa, Portugal
| | - S. Jacinto
- Inherited Metabolic Diseases Reference Centre, Lisboa Central Hospital Centre, Lisboa, Portugal
| | - J. P. Vieira
- Inherited Metabolic Diseases Reference Centre, Lisboa Central Hospital Centre, Lisboa, Portugal
| | - L. Diogo
- Inherited Metabolic Diseases Reference Centre, Coimbra Hospital and University Centre, Coimbra, Portugal
| | - H. Santos
- Inherited Metabolic Diseases Reference Centre, Vila Nova de Gaia Hospital Centre, Vila Nova de Gaia, Portugal
| | - C. Mendonça
- Pediatric Department, Faro Hospital and University Centre, Faro, Portugal
| | - L. Vilarinho
- Research & Development Unit, Human Genetics Department, National Institute of Health Doutor Ricardo Jorge, Lisbon, Portugal
- Newborn Screening, Metabolism & Genetics Unit, Human Genetics Department, National Institute of Health Doutor Ricardo Jorge, Lisbon, Portugal
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7
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Baker ZN, Forny P, Pagliarini DJ. Mitochondrial proteome research: the road ahead. Nat Rev Mol Cell Biol 2024; 25:65-82. [PMID: 37773518 DOI: 10.1038/s41580-023-00650-7] [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] [Accepted: 08/08/2023] [Indexed: 10/01/2023]
Abstract
Mitochondria are multifaceted organelles with key roles in anabolic and catabolic metabolism, bioenergetics, cellular signalling and nutrient sensing, and programmed cell death processes. Their diverse functions are enabled by a sophisticated set of protein components encoded by the nuclear and mitochondrial genomes. The extent and complexity of the mitochondrial proteome remained unclear for decades. This began to change 20 years ago when, driven by the emergence of mass spectrometry-based proteomics, the first draft mitochondrial proteomes were established. In the ensuing decades, further technological and computational advances helped to refine these 'maps', with current estimates of the core mammalian mitochondrial proteome ranging from 1,000 to 1,500 proteins. The creation of these compendia provided a systemic view of an organelle previously studied primarily in a reductionist fashion and has accelerated both basic scientific discovery and the diagnosis and treatment of human disease. Yet numerous challenges remain in understanding mitochondrial biology and translating this knowledge into the medical context. In this Roadmap, we propose a path forward for refining the mitochondrial protein map to enhance its discovery and therapeutic potential. We discuss how emerging technologies can assist the detection of new mitochondrial proteins, reveal their patterns of expression across diverse tissues and cell types, and provide key information on proteoforms. We highlight the power of an enhanced map for systematically defining the functions of its members. Finally, we examine the utility of an expanded, functionally annotated mitochondrial proteome in a translational setting for aiding both diagnosis of mitochondrial disease and targeting of mitochondria for treatment.
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Affiliation(s)
- Zakery N Baker
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Patrick Forny
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO, USA
| | - David J Pagliarini
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO, USA.
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO, USA.
- Department of Genetics, Washington University School of Medicine, St. Louis, MO, USA.
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8
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Indelicato E, Boesch S, Mencacci NE, Ghezzi D, Prokisch H, Winkelmann J, Zech M. Dystonia in ATP Synthase Defects: Reconnecting Mitochondria and Dopamine. Mov Disord 2024; 39:29-35. [PMID: 37964479 DOI: 10.1002/mds.29657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 10/16/2023] [Accepted: 10/20/2023] [Indexed: 11/16/2023] Open
Affiliation(s)
- Elisabetta Indelicato
- Center for Rare Movement Disorders Innsbruck, Department of Neurology, Medical University Innsbruck, Innsbruck, Austria
- Institute of Neurogenomics, Helmholtz Munich, Neuherberg, Germany
- Institute of Human Genetics, Technical University of Munich, School of Medicine, Munich, Germany
| | - Sylvia Boesch
- Center for Rare Movement Disorders Innsbruck, Department of Neurology, Medical University Innsbruck, Innsbruck, Austria
| | - Niccolo' E Mencacci
- Ken and Ruth Davee Department of Neurology and Simpson Querrey Center for Neurogenetics, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA
| | - Daniele Ghezzi
- Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
- Department of Pathophysiology and Transplantation (DEPT), University of Milan, Milan, Italy
| | - Holger Prokisch
- Institute of Neurogenomics, Helmholtz Munich, Neuherberg, Germany
- Institute of Human Genetics, Technical University of Munich, School of Medicine, Munich, Germany
| | - Juliane Winkelmann
- Institute of Neurogenomics, Helmholtz Munich, Neuherberg, Germany
- Institute of Human Genetics, Technical University of Munich, School of Medicine, Munich, Germany
- DZPG, Deutsches Zentrum für Psychische Gesundheit, Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Michael Zech
- Institute of Neurogenomics, Helmholtz Munich, Neuherberg, Germany
- Institute of Human Genetics, Technical University of Munich, School of Medicine, Munich, Germany
- Institute for Advanced Study, Technical University of Munich, Garching, Germany
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9
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Gropman AL, Uittenbogaard MN, Chiaramello AE. Challenges and opportunities to bridge translational to clinical research for personalized mitochondrial medicine. Neurotherapeutics 2024; 21:e00311. [PMID: 38266483 PMCID: PMC10903101 DOI: 10.1016/j.neurot.2023.e00311] [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: 10/12/2023] [Revised: 12/08/2023] [Accepted: 12/13/2023] [Indexed: 01/26/2024] Open
Abstract
Mitochondrial disorders are a group of rare and heterogeneous genetic diseases characterized by dysfunctional mitochondria leading to deficient adenosine triphosphate synthesis and chronic energy deficit in patients. The majority of these patients exhibit a wide range of phenotypic manifestations targeting several organ systems, making their clinical diagnosis and management challenging. Bridging translational to clinical research is crucial for improving the early diagnosis and prognosis of these intractable mitochondrial disorders and for discovering novel therapeutic drug candidates and modalities. This review provides the current state of clinical testing in mitochondrial disorders, discusses the challenges and opportunities for converting basic discoveries into clinical settings, explores the most suited patient-centric approaches to harness the extraordinary heterogeneity among patients affected by the same primary mitochondrial disorder, and describes the current outlook of clinical trials.
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Affiliation(s)
- Andrea L Gropman
- Children's National Medical Center, Division of Neurogenetics and Neurodevelopmental Pediatrics, Washington, DC 20010, USA
| | - Martine N Uittenbogaard
- Department of Anatomy and Cell Biology, George Washington University School of Medicine and Health Sciences, Washington, DC 20037, USA
| | - Anne E Chiaramello
- Department of Anatomy and Cell Biology, George Washington University School of Medicine and Health Sciences, Washington, DC 20037, USA.
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10
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Parikh F, Athalye A, Madon P, Khandeparkar M, Naik D, Sanap R, Udumudi A. Genetic counseling for pre-implantation genetic testing of monogenic disorders (PGT-M). FRONTIERS IN REPRODUCTIVE HEALTH 2023; 5:1213546. [PMID: 38162012 PMCID: PMC10755023 DOI: 10.3389/frph.2023.1213546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 12/04/2023] [Indexed: 01/03/2024] Open
Abstract
Pre-implantation genetic testing (PGT) is a vital tool in preventing chromosomal aneuploidies and other genetic disorders including those that are monogenic in origin. It is performed on embryos created by intracytoplasmic sperm injection (ICSI). Genetic counseling in the area of assisted reproductive technology (ART) has also evolved along with PGT and is considered an essential and integral part of Reproductive Medicine. While PGT has the potential to prevent future progeny from being affected by genetic conditions, genetic counseling helps couples understand and adapt to the medical, psychological, familial and social implications of the genetic contribution to disease. Genetic counseling is particularly helpful for couples with recurrent miscarriages, advanced maternal age, a partner with a chromosome translocation or inversion, those in a consanguineous marriage, and those using donor gametes. Partners with a family history of genetic conditions including hereditary cancer, late onset neurological diseases and with a carrier status for monogenic disorders can benefit from genetic counseling when undergoing PGT for monogenic disorders (PGT-M). Genetic counseling for PGT is useful in cases of Mendelian disorders, autosomal dominant and recessive conditions and sex chromosome linked disorders and for the purposes of utilizing HLA matching technology for creating a savior sibling. It also helps in understanding the importance of PGT in cases of variants of uncertain significance (VUS) and variable penetrance. The possibilities and limitations are discussed in detail during the sessions of genetic counseling.
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Affiliation(s)
- Firuza Parikh
- Department of Assisted Reproduction and Genetics, Jaslok-FertilTree International Fertility Centre, Jaslok Hospital and Research Centre, Mumbai, India
| | - Arundhati Athalye
- Department of Assisted Reproduction and Genetics, Jaslok-FertilTree International Fertility Centre, Jaslok Hospital and Research Centre, Mumbai, India
| | - Prochi Madon
- Department of Assisted Reproduction and Genetics, Jaslok-FertilTree International Fertility Centre, Jaslok Hospital and Research Centre, Mumbai, India
| | - Meenal Khandeparkar
- Department of Assisted Reproduction and Genetics, Jaslok-FertilTree International Fertility Centre, Jaslok Hospital and Research Centre, Mumbai, India
| | - Dattatray Naik
- Department of Assisted Reproduction and Genetics, Jaslok-FertilTree International Fertility Centre, Jaslok Hospital and Research Centre, Mumbai, India
| | - Rupesh Sanap
- Department of Assisted Reproduction and Genetics, Jaslok-FertilTree International Fertility Centre, Jaslok Hospital and Research Centre, Mumbai, India
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11
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Brechtmann F, Bechtler T, Londhe S, Mertes C, Gagneur J. Evaluation of input data modality choices on functional gene embeddings. NAR Genom Bioinform 2023; 5:lqad095. [PMID: 37942285 PMCID: PMC10629286 DOI: 10.1093/nargab/lqad095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 09/07/2023] [Accepted: 09/28/2023] [Indexed: 11/10/2023] Open
Abstract
Functional gene embeddings, numerical vectors capturing gene function, provide a promising way to integrate functional gene information into machine learning models. These embeddings are learnt by applying self-supervised machine-learning algorithms on various data types including quantitative omics measurements, protein-protein interaction networks and literature. However, downstream evaluations comparing alternative data modalities used to construct functional gene embeddings have been lacking. Here we benchmarked functional gene embeddings obtained from various data modalities for predicting disease-gene lists, cancer drivers, phenotype-gene associations and scores from genome-wide association studies. Off-the-shelf predictors trained on precomputed embeddings matched or outperformed dedicated state-of-the-art predictors, demonstrating their high utility. Embeddings based on literature and protein-protein interactions inferred from low-throughput experiments outperformed embeddings derived from genome-wide experimental data (transcriptomics, deletion screens and protein sequence) when predicting curated gene lists. In contrast, they did not perform better when predicting genome-wide association signals and were biased towards highly-studied genes. These results indicate that embeddings derived from literature and low-throughput experiments appear favourable in many existing benchmarks because they are biased towards well-studied genes and should therefore be considered with caution. Altogether, our study and precomputed embeddings will facilitate the development of machine-learning models in genetics and related fields.
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Affiliation(s)
- Felix Brechtmann
- TUM School of Computation, Information and Technology, Technical University of Munich, Garching, Germany
- Munich Center for Machine Learning, Munich, Germany
| | - Thibault Bechtler
- TUM School of Computation, Information and Technology, Technical University of Munich, Garching, Germany
| | - Shubhankar Londhe
- TUM School of Computation, Information and Technology, Technical University of Munich, Garching, Germany
| | - Christian Mertes
- TUM School of Computation, Information and Technology, Technical University of Munich, Garching, Germany
- Munich Data Science Institute, Technical University of Munich, Garching, Germany
- Institute of Human Genetics, School of Medicine, Technical University of Munich, Munich, Germany
| | - Julien Gagneur
- TUM School of Computation, Information and Technology, Technical University of Munich, Garching, Germany
- Institute of Human Genetics, School of Medicine, Technical University of Munich, Munich, Germany
- Computational Health Center, Helmholtz Center Munich, Neuherberg, Germany
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12
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Conti F, Di Martino S, Drago F, Bucolo C, Micale V, Montano V, Siciliano G, Mancuso M, Lopriore P. Red Flags in Primary Mitochondrial Diseases: What Should We Recognize? Int J Mol Sci 2023; 24:16746. [PMID: 38069070 PMCID: PMC10706469 DOI: 10.3390/ijms242316746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 11/22/2023] [Accepted: 11/23/2023] [Indexed: 12/18/2023] Open
Abstract
Primary mitochondrial diseases (PMDs) are complex group of metabolic disorders caused by genetically determined impairment of the mitochondrial oxidative phosphorylation (OXPHOS). The unique features of mitochondrial genetics and the pivotal role of mitochondria in cell biology explain the phenotypical heterogeneity of primary mitochondrial diseases and the resulting diagnostic challenges that follow. Some peculiar features ("red flags") may indicate a primary mitochondrial disease, helping the physician to orient in this diagnostic maze. In this narrative review, we aimed to outline the features of the most common mitochondrial red flags offering a general overview on the topic that could help physicians to untangle mitochondrial medicine complexity.
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Affiliation(s)
- Federica Conti
- Department of Biomedical and Biotechnological Science, School of Medicine, University of Catania, 95123 Catania, Italy; (F.C.); (S.D.M.); (C.B.); (V.M.)
| | - Serena Di Martino
- Department of Biomedical and Biotechnological Science, School of Medicine, University of Catania, 95123 Catania, Italy; (F.C.); (S.D.M.); (C.B.); (V.M.)
| | - Filippo Drago
- Department of Biomedical and Biotechnological Science, School of Medicine, University of Catania, 95123 Catania, Italy; (F.C.); (S.D.M.); (C.B.); (V.M.)
| | - Claudio Bucolo
- Department of Biomedical and Biotechnological Science, School of Medicine, University of Catania, 95123 Catania, Italy; (F.C.); (S.D.M.); (C.B.); (V.M.)
- Center for Research in Ocular Pharmacology-CERFO, University of Catania, 95213 Catania, Italy
| | - Vincenzo Micale
- Department of Biomedical and Biotechnological Science, School of Medicine, University of Catania, 95123 Catania, Italy; (F.C.); (S.D.M.); (C.B.); (V.M.)
| | - Vincenzo Montano
- Neurological Institute, Department of Clinical and Experimental Medicine, University of Pisa, 56126 Pisa, Italy (P.L.)
| | - Gabriele Siciliano
- Neurological Institute, Department of Clinical and Experimental Medicine, University of Pisa, 56126 Pisa, Italy (P.L.)
| | - Michelangelo Mancuso
- Neurological Institute, Department of Clinical and Experimental Medicine, University of Pisa, 56126 Pisa, Italy (P.L.)
| | - Piervito Lopriore
- Neurological Institute, Department of Clinical and Experimental Medicine, University of Pisa, 56126 Pisa, Italy (P.L.)
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13
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Albensi BC. Editorial: Are Mitochondrial Therapeutics the Next Disruptor in Molecular Healthcare? Mol Neurobiol 2023:10.1007/s12035-023-03653-9. [PMID: 37773083 PMCID: PMC11034766 DOI: 10.1007/s12035-023-03653-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/30/2023]
Affiliation(s)
- Benedict C Albensi
- College of Pharmacy, Nova Southeastern University, 3200 South University Drive, Ft. Lauderdale, FL, 33328, USA.
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14
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Clemente-Suárez VJ, Redondo-Flórez L, Beltrán-Velasco AI, Ramos-Campo DJ, Belinchón-deMiguel P, Martinez-Guardado I, Dalamitros AA, Yáñez-Sepúlveda R, Martín-Rodríguez A, Tornero-Aguilera JF. Mitochondria and Brain Disease: A Comprehensive Review of Pathological Mechanisms and Therapeutic Opportunities. Biomedicines 2023; 11:2488. [PMID: 37760929 PMCID: PMC10526226 DOI: 10.3390/biomedicines11092488] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 09/02/2023] [Accepted: 09/04/2023] [Indexed: 09/29/2023] Open
Abstract
Mitochondria play a vital role in maintaining cellular energy homeostasis, regulating apoptosis, and controlling redox signaling. Dysfunction of mitochondria has been implicated in the pathogenesis of various brain diseases, including neurodegenerative disorders, stroke, and psychiatric illnesses. This review paper provides a comprehensive overview of the intricate relationship between mitochondria and brain disease, focusing on the underlying pathological mechanisms and exploring potential therapeutic opportunities. The review covers key topics such as mitochondrial DNA mutations, impaired oxidative phosphorylation, mitochondrial dynamics, calcium dysregulation, and reactive oxygen species generation in the context of brain disease. Additionally, it discusses emerging strategies targeting mitochondrial dysfunction, including mitochondrial protective agents, metabolic modulators, and gene therapy approaches. By critically analysing the existing literature and recent advancements, this review aims to enhance our understanding of the multifaceted role of mitochondria in brain disease and shed light on novel therapeutic interventions.
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Affiliation(s)
- Vicente Javier Clemente-Suárez
- Faculty of Sports Sciences, Universidad Europea de Madrid, Tajo Street, s/n, 28670 Madrid, Spain; (V.J.C.-S.); (J.F.T.-A.)
- Group de Investigación en Cultura, Educación y Sociedad, Universidad de la Costa, Barranquilla 080002, Colombia
| | - Laura Redondo-Flórez
- Department of Health Sciences, Faculty of Biomedical and Health Sciences, Universidad Europea de Madrid, C/Tajo s/n, Villaviciosa de Odón, 28670 Madrid, Spain
| | - Ana Isabel Beltrán-Velasco
- Psychology Department, Facultad de Ciencias de la Vida y la Naturaleza, Universidad Antonio de Nebrija, 28240 Madrid, Spain
| | - Domingo Jesús Ramos-Campo
- LFE Research Group, Department of Health and Human Performance, Faculty of Physical Activity and Sport Science-INEF, Universidad Politécnica de Madrid, 28040 Madrid, Spain
| | - Pedro Belinchón-deMiguel
- Department of Nursing and Nutrition, Faculty of Biomedical and Health Sciences, Universidad Europea de Madrid, 28670 Villaviciosa de Odón, Spain;
| | | | - Athanasios A. Dalamitros
- Laboratory of Evaluation of Human Biological Performance, School of Physical Education and Sport Sciences, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece;
| | - Rodrigo Yáñez-Sepúlveda
- Faculty of Education and Social Sciences, Universidad Andres Bello, Viña del Mar 2520000, Chile;
| | - Alexandra Martín-Rodríguez
- Faculty of Sports Sciences, Universidad Europea de Madrid, Tajo Street, s/n, 28670 Madrid, Spain; (V.J.C.-S.); (J.F.T.-A.)
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15
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Gedikbasi A, Toksoy G, Karaca M, Gulec C, Balci MC, Gunes D, Gunes S, Aslanger AD, Unverengil G, Karaman B, Basaran S, Demirkol M, Gokcay GF, Uyguner ZO. Clinical and bi-genomic DNA findings of patients suspected to have mitochondrial diseases. Front Genet 2023; 14:1191159. [PMID: 37377599 PMCID: PMC10292751 DOI: 10.3389/fgene.2023.1191159] [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: 03/21/2023] [Accepted: 05/02/2023] [Indexed: 06/29/2023] Open
Abstract
Background: Mitochondrial diseases are the most common group of inherited metabolic disorders, causing difficulties in definite diagnosis due to clinical and genetic heterogeneity. Clinical components are predominantly associated with pathogenic variants shown in nuclear or mitochondrial genomes that affect vital respiratory chain function. The development of high-throughput sequencing technologies has accelerated the elucidation of the genetic etiology of many genetic diseases that previously remained undiagnosed. Methods: Thirty affected patients from 24 unrelated families with clinical, radiological, biochemical, and histopathological evaluations considered for mitochondrial diseases were investigated. DNA isolated from the peripheral blood samples of probands was sequenced for nuclear exome and mitochondrial DNA (mtDNA) analyses. MtDNA sequencing was also performed from the muscle biopsy material in one patient. For segregation, Sanger sequencing is performed for pathogenic alterations in five other affected family members and healthy parents. Results: Exome sequencing revealed 14 different pathogenic variants in nine genes encoding mitochondrial function peptides (AARS2, EARS2, ECHS1, FBXL4, MICOS13, NDUFAF6, OXCT1, POLG, and TK2) in 12 patients from nine families and four variants in genes encoding important for muscle structure (CAPN3, DYSF, and TCAP) in six patients from four families. Three probands carried pathogenic mtDNA variations in two genes (MT-ATP6 and MT-TL1). Nine variants in five genes are reported for the first time with disease association: (AARS2: c.277C>T/p.(R93*), c.845C>G/p.(S282C); EARS2: c.319C>T/p.(R107C), c.1283delC/p.(P428Lfs*); ECHS1: c.161G>A/p.(R54His); c.202G>A/p.(E68Lys); NDUFAF6: c.479delA/p.(N162Ifs*27); and OXCT1: c.1370C>T/p.(T457I), c.1173-139G>T/p.(?). Conclusion: Bi-genomic DNA sequencing clarified genetic etiology in 67% (16/24) of the families. Diagnostic utility by mtDNA sequencing in 13% (3/24) and exome sequencing in 54% (13/24) of the families prioritized searching for nuclear genome pathologies for the first-tier test. Weakness and muscle wasting observed in 17% (4/24) of the families underlined that limb-girdle muscular dystrophy, similar to mitochondrial myopathy, is an essential point for differential diagnosis. The correct diagnosis is crucial for comprehensive genetic counseling of families. Also, it contributes to making treatment-helpful referrals, such as ensuring early access to medication for patients with mutations in the TK2 gene.
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Affiliation(s)
- Asuman Gedikbasi
- Department of Pediatric Basic Sciences, Institute of Child Health Istanbul University, Istanbul, Türkiye
- Division of Pediatric Nutrition and Metabolism, Department of Pediatrics, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Türkiye
| | - Guven Toksoy
- Department of Medical Genetics, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Türkiye
| | - Meryem Karaca
- Division of Pediatric Nutrition and Metabolism, Department of Pediatrics, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Türkiye
| | - Cagri Gulec
- Department of Medical Genetics, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Türkiye
| | - Mehmet Cihan Balci
- Division of Pediatric Nutrition and Metabolism, Department of Pediatrics, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Türkiye
| | - Dilek Gunes
- Division of Pediatric Nutrition and Metabolism, Department of Pediatrics, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Türkiye
| | - Seda Gunes
- Division of Pediatric Nutrition and Metabolism, Department of Pediatrics, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Türkiye
| | - Ayca Dilruba Aslanger
- Department of Medical Genetics, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Türkiye
| | - Gokcen Unverengil
- Department of Pathology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Türkiye
| | - Birsen Karaman
- Department of Pediatric Basic Sciences, Institute of Child Health Istanbul University, Istanbul, Türkiye
- Department of Medical Genetics, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Türkiye
| | - Seher Basaran
- Department of Medical Genetics, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Türkiye
| | - Mubeccel Demirkol
- Division of Pediatric Nutrition and Metabolism, Department of Pediatrics, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Türkiye
| | - Gulden Fatma Gokcay
- Division of Pediatric Nutrition and Metabolism, Department of Pediatrics, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Türkiye
| | - Zehra Oya Uyguner
- Department of Medical Genetics, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Türkiye
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16
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Mitochondrial Dysfunction in Intensive Care Unit-Acquired Weakness and Critical Illness Myopathy: A Narrative Review. Int J Mol Sci 2023; 24:ijms24065516. [PMID: 36982590 PMCID: PMC10052131 DOI: 10.3390/ijms24065516] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 03/03/2023] [Accepted: 03/09/2023] [Indexed: 03/16/2023] Open
Abstract
Mitochondria are key structures providing most of the energy needed to maintain homeostasis. They are the main source of adenosine triphosphate (ATP), participate in glucose, lipid and amino acid metabolism, store calcium and are integral components in various intracellular signaling cascades. However, due to their crucial role in cellular integrity, mitochondrial damage and dysregulation in the context of critical illness can severely impair organ function, leading to energetic crisis and organ failure. Skeletal muscle tissue is rich in mitochondria and, therefore, particularly vulnerable to mitochondrial dysfunction. Intensive care unit-acquired weakness (ICUAW) and critical illness myopathy (CIM) are phenomena of generalized weakness and atrophying skeletal muscle wasting, including preferential myosin breakdown in critical illness, which has also been linked to mitochondrial failure. Hence, imbalanced mitochondrial dynamics, dysregulation of the respiratory chain complexes, alterations in gene expression, disturbed signal transduction as well as impaired nutrient utilization have been proposed as underlying mechanisms. This narrative review aims to highlight the current known molecular mechanisms immanent in mitochondrial dysfunction of patients suffering from ICUAW and CIM, as well as to discuss possible implications for muscle phenotype, function and therapeutic approaches.
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17
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Wong TS, Belaramani KM, Chan CK, Chan WK, Chan WLL, Chang SK, Cheung SN, Cheung KY, Cheung YF, Chong SCJ, Chow CKJ, Chung HYB, Fan SYF, Fok WMJ, Fong KW, Fung THS, Hui KF, Hui TH, Hui J, Ko CH, Kwan MC, Kwok MKA, Kwok SSJ, Lai MS, Lam YO, Lam CW, Lau MC, Law CYE, Lee WC, Lee HCH, Lee CN, Leung KH, Leung KY, Li SH, Ling TKJ, Liu KTT, Lo FM, Lui HT, Luk CO, Luk HM, Ma CK, Ma K, Ma KH, Mew YN, Mo A, Ng SF, Poon WKG, Rodenburg R, Sheng B, Smeitink J, Szeto CLC, Tai SM, Tse CTA, Tsung LYL, Wong HMJ, Wong WYW, Wong KK, Wong SNS, Wong CNV, Wong WSS, Wong CKF, Wu SP, Wu HFJ, Yau MM, Yau KCE, Yeung WL, Yeung HMJ, Yip KKE, Young PHT, Yuan G, Yuen YPL, Yuen CL, Fung CW. Mitochondrial diseases in Hong Kong: prevalence, clinical characteristics and genetic landscape. Orphanet J Rare Dis 2023; 18:43. [PMID: 36859275 PMCID: PMC9979401 DOI: 10.1186/s13023-023-02632-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 02/06/2023] [Indexed: 03/03/2023] Open
Abstract
OBJECTIVE To determine the prevalence of mitochondrial diseases (MD) in Hong Kong (HK) and to evaluate the clinical characteristics and genetic landscape of MD patients in the region. METHODS This study retrospectively reviewed the phenotypic and molecular characteristics of MD patients from participating public hospitals in HK between January 1985 to October 2020. Molecularly and/or enzymatically confirmed MD cases of any age were recruited via the Clinical Analysis and Reporting System (CDARS) using relevant keywords and/or International Classification of Disease (ICD) codes under the HK Hospital Authority or through the personal recollection of treating clinicians among the investigators. RESULTS A total of 119 MD patients were recruited and analyzed in the study. The point prevalence of MD in HK was 1.02 in 100,000 people (95% confidence interval 0.81-1.28 in 100,000). 110 patients had molecularly proven MD and the other nine were diagnosed by OXPHOS enzymology analysis or mitochondrial DNA depletion analysis with unknown molecular basis. Pathogenic variants in the mitochondrial genome (72 patients) were more prevalent than those in the nuclear genome (38 patients) in our cohort. The most commonly involved organ system at disease onset was the neurological system, in which developmental delay, seizures or epilepsy, and stroke-like episodes were the most frequently reported presentations. The mortality rate in our cohort was 37%. CONCLUSION This study is a territory-wide overview of the clinical and genetic characteristics of MD patients in a Chinese population, providing the first available prevalence rate of MD in Hong Kong. The findings of this study aim to facilitate future in-depth evaluation of MD and lay the foundation to establish a local MD registry.
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Affiliation(s)
- Tsz-Sum Wong
- Department of Paediatrics and Adolescent Medicine, Princess Margaret Hospital, Hong Kong, SAR, People's Republic of China
| | - Kiran M Belaramani
- Department of Paediatrics and Adolescent Medicine, Hong Kong Children's Hospital, Hong Kong, SAR, People's Republic of China
| | - Chun-Kong Chan
- Department of Medicine and Geriatrics, United Christian Hospital, Hong Kong, SAR, People's Republic of China
| | - Wing-Ki Chan
- Department of Paediatrics and Adolescent Medicine, Princess Margaret Hospital, Hong Kong, SAR, People's Republic of China
| | - Wai-Lun Larry Chan
- Department of Medicine, Alice Ho Miu Ling Nethersole Hospital, Hong Kong, SAR, People's Republic of China
| | - Shek-Kwan Chang
- Department of Medicine, Queen Mary Hospital, Hong Kong, SAR, People's Republic of China
| | - Sing-Ngai Cheung
- Department of Medicine and Geriatrics, Kwong Wah Hospital, Hong Kong, SAR, People's Republic of China
| | - Ka-Yin Cheung
- Department of Medicine and Geriatrics, United Christian Hospital, Hong Kong, SAR, People's Republic of China
| | - Yuk-Fai Cheung
- Department of Medicine, Queen Elizabeth Hospital, Hong Kong, SAR, People's Republic of China
| | - Shuk-Ching Josephine Chong
- Department of Paediatrics, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, SAR, People's Republic of China
| | - Chi-Kwan Jasmine Chow
- Department of Paediatrics and Adolescent Medicine, Queen Elizabeth Hospital, Hong Kong, SAR, People's Republic of China
| | - Hon-Yin Brian Chung
- Department of Paediatrics & Adolescent Medicine, School of Clinical Medicine, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, SAR, People's Republic of China
- Hong Kong Genome Institute, Hong Kong, SAR, People's Republic of China
| | - Sin-Ying Florence Fan
- Department of Medicine and Therapeutics, Prince of Wales Hospital, Hong Kong, SAR, People's Republic of China
| | - Wai-Ming Joshua Fok
- Department of Medicine, Yan Chai Hospital, Hong Kong, SAR, People's Republic of China
| | - Ka-Wing Fong
- Department of Medicine, Queen Elizabeth Hospital, Hong Kong, SAR, People's Republic of China
| | - Tsui-Hang Sharon Fung
- Department of Paediatrics and Adolescent Medicine, Kwong Wah Hospital, Hong Kong, SAR, People's Republic of China
| | - Kwok-Fai Hui
- Department of Medicine and Geriatrics, United Christian Hospital, Hong Kong, SAR, People's Republic of China
| | - Ting-Hin Hui
- Department of Medicine and Geriatrics, United Christian Hospital, Hong Kong, SAR, People's Republic of China
| | - Joannie Hui
- Department of Paediatrics and Adolescent Medicine, Hong Kong Children's Hospital, Hong Kong, SAR, People's Republic of China
| | - Chun-Hung Ko
- Department of Paediatrics and Adolescent Medicine, Caritas Medical Centre, Hong Kong, SAR, People's Republic of China
| | - Min-Chung Kwan
- Department of Medicine and Geriatrics, Kwong Wah Hospital, Hong Kong, SAR, People's Republic of China
| | - Mei-Kwan Anne Kwok
- Department of Paediatrics and Adolescent Medicine, Hong Kong Children's Hospital, Hong Kong, SAR, People's Republic of China
| | - Sung-Shing Jeffrey Kwok
- Department of Chemical Pathology, Prince of Wales Hospital, Hong Kong, SAR, People's Republic of China
| | - Moon-Sing Lai
- Department of Medicine, North District Hospital, Hong Kong, SAR, People's Republic of China
| | - Yau-On Lam
- Department of Medicine and Geriatrics, United Christian Hospital, Hong Kong, SAR, People's Republic of China
| | - Ching-Wan Lam
- Department of Pathology, The University of Hong Kong, Hong Kong, SAR, People's Republic of China
| | - Ming-Chung Lau
- Department of Paediatrics and Adolescent Medicine, United Christian Hospital, Hong Kong, SAR, People's Republic of China
| | - Chun-Yiu Eric Law
- Department of Chemical Pathology, Queen Mary Hospital, Hong Kong, SAR, People's Republic of China
| | - Wing-Cheong Lee
- Department of Paediatrics and Adolescent Medicine, Pamela Youde Nethersole Eastern Hospital, Hong Kong, SAR, People's Republic of China
| | - Han-Chih Hencher Lee
- Department of Chemical Pathology, Princess Margaret Hospital, Hong Kong, SAR, People's Republic of China
| | - Chin-Nam Lee
- Department of Medicine, Pamela Youde Nethersole Eastern Hospital, Hong Kong, SAR, People's Republic of China
| | - Kin-Hang Leung
- Department of Medicine, Queen Elizabeth Hospital, Hong Kong, SAR, People's Republic of China
| | - Kit-Yan Leung
- Department of Paediatrics and Adolescent Medicine, Princess Margaret Hospital, Hong Kong, SAR, People's Republic of China
| | - Siu-Hung Li
- Department of Medicine, North District Hospital, Hong Kong, SAR, People's Republic of China
| | - Tsz-Ki Jacky Ling
- Department of Chemical Pathology, Queen Mary Hospital, Hong Kong, SAR, People's Republic of China
| | - Kam-Tim Timothy Liu
- Department of Paediatrics and Adolescent Medicine, Pamela Youde Nethersole Eastern Hospital, Hong Kong, SAR, People's Republic of China
| | - Fai-Man Lo
- Department of Health, Clinical Genetic Service, Hong Kong, SAR, People's Republic of China
| | - Hiu-Tung Lui
- Department of Medicine, Tseung Kwan O Hospital, Hong Kong, SAR, People's Republic of China
| | - Ching-On Luk
- Department of Medicine, Queen Elizabeth Hospital, Hong Kong, SAR, People's Republic of China
| | - Ho-Ming Luk
- Clinical Genetics Service Unit, Hong Kong Children's Hospital, Hong Kong, SAR, People's Republic of China
| | - Che-Kwan Ma
- Department of Paediatrics and Adolescent Medicine, United Christian Hospital, Hong Kong, SAR, People's Republic of China
| | - Karen Ma
- Department of Medicine and Therapeutics, Prince of Wales Hospital, Hong Kong, SAR, People's Republic of China
| | - Kam-Hung Ma
- Department of Paediatrics and Adolescent Medicine, Alice Ho Miu Ling Nethersole hospital, Hong Kong, SAR, People's Republic of China
| | - Yuen-Ni Mew
- Department of Medicine and Geriatrics, United Christian Hospital, Hong Kong, SAR, People's Republic of China
| | - Alex Mo
- Department of Paediatrics and Adolescent Medicine, Kwong Wah Hospital, Hong Kong, SAR, People's Republic of China
| | - Sui-Fun Ng
- Department of Paediatrics and Adolescent Medicine, Princess Margaret Hospital, Hong Kong, SAR, People's Republic of China
| | - Wing-Kit Grace Poon
- Department of Paediatrics and Adolescent Medicine, Queen Mary Hospital, Hong Kong, SAR, People's Republic of China
| | - Richard Rodenburg
- Department of Paediatrics, Radboud Centre for Mitochondrial Medicine, Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen Medicine Centre, Nijmegen, The Netherlands
| | - Bun Sheng
- Department of Medicine and Geriatrics, Princess Margaret Hospital, Hong Kong, SAR, People's Republic of China
| | - Jan Smeitink
- Department of Paediatrics, Radboud Centre for Mitochondrial Medicine, Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen Medicine Centre, Nijmegen, The Netherlands
| | - Cheuk-Ling Charing Szeto
- Department of Medicine and Geriatrics, United Christian Hospital, Hong Kong, SAR, People's Republic of China
| | - Shuk-Mui Tai
- Department of Paediatrics and Adolescent Medicine, Pamela Youde Nethersole Eastern Hospital, Hong Kong, SAR, People's Republic of China
| | - Choi-Ting Alan Tse
- Department of Medicine, Yan Chai Hospital, Hong Kong, SAR, People's Republic of China
| | - Li-Yan Lilian Tsung
- Department of Paediatrics and Adolescent Medicine, Pamela Youde Nethersole Eastern Hospital, Hong Kong, SAR, People's Republic of China
| | - Ho-Ming June Wong
- Department of Medicine and Geriatrics, Caritas Medical Centre, Hong Kong, SAR, People's Republic of China
| | - Wing-Yin Winnie Wong
- Department of Medicine and Geriatrics, Caritas Medical Centre, Hong Kong, SAR, People's Republic of China
| | - Kwok-Kui Wong
- Department of Medicine, Yan Chai Hospital, Hong Kong, SAR, People's Republic of China
| | - Suet-Na Sheila Wong
- Department of Paediatrics and Adolescent Medicine, Hong Kong Children's Hospital, Hong Kong, SAR, People's Republic of China
| | - Chun-Nei Virginia Wong
- Department of Paediatrics & Adolescent Medicine, School of Clinical Medicine, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, SAR, People's Republic of China
| | - Wai-Shan Sammy Wong
- Department of Pathology, Queen Elizabeth Hospital, Hong Kong, SAR, People's Republic of China
| | - Chi-Kin Felix Wong
- Department of Chemical Pathology, Queen Mary Hospital, Hong Kong, SAR, People's Republic of China
| | - Shun-Ping Wu
- Department of Paediatrics and Adolescent Medicine, Queen Elizabeth Hospital, Hong Kong, SAR, People's Republic of China
| | - Hiu-Fung Jerome Wu
- Department of Medicine and Geriatrics, Princess Margaret Hospital, Hong Kong, SAR, People's Republic of China
| | - Man-Mut Yau
- Department of Paediatrics and Adolescent Medicine, Tseung Kwan O Hospital, Hong Kong, SAR, People's Republic of China
| | - Kin-Cheong Eric Yau
- Department of Paediatrics and Adolescent Medicine, Princess Margaret Hospital, Hong Kong, SAR, People's Republic of China
| | - Wai-Lan Yeung
- Department of Paediatrics and Adolescent Medicine, Hong Kong Children's Hospital, Hong Kong, SAR, People's Republic of China
| | - Hon-Ming Jonas Yeung
- Department of Medicine, Alice Ho Miu Ling Nethersole Hospital, Hong Kong, SAR, People's Republic of China
| | - Kin-Keung Edwin Yip
- Department of Medicine and Geriatrics, Ruttonjee and Tang Shiu Kin Hospitals, Hong Kong, SAR, People's Republic of China
| | - Pui-Hong Terence Young
- Department of Medicine and Geriatrics, Ruttonjee and Tang Shiu Kin Hospitals, Hong Kong, SAR, People's Republic of China
| | - Gao Yuan
- Department of Medicine, Queen Mary Hospital, Hong Kong, SAR, People's Republic of China
| | - Yuet-Ping Liz Yuen
- Department of Chemical Pathology, Hong Kong Children's Hospital, Hong Kong, SAR, People's Republic of China
| | - Chi-Lap Yuen
- Department of Medicine and Geriatrics, Tuen Mun Hospital, Hong Kong, SAR, People's Republic of China
| | - Cheuk-Wing Fung
- Department of Paediatrics and Adolescent Medicine, Hong Kong Children's Hospital, Hong Kong, SAR, People's Republic of China.
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Legati A, Ghezzi D, Viscomi C. Mitochondrial DNA Sequencing and Heteroplasmy Quantification by Next Generation Sequencing. Methods Mol Biol 2023; 2615:381-395. [PMID: 36807805 DOI: 10.1007/978-1-0716-2922-2_26] [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
Over the last 10 years, next generation sequencing (NGS) became the gold standard for both diagnosis and discovery of new disease genes responsible for heterogeneous disorders, such as mitochondrial encephalomyopathies. The application of this technology to mtDNA mutations poses extra challenges compared to other genetic conditions because of the peculiarities of mitochondrial genetics and the requirement for proper NGS data management and analysis. Here, we describe a detailed, clinically relevant protocol to sequence the whole mtDNA and quantify heteroplasmy levels of mtDNA variants, starting from total DNA through the generation of a single PCR amplicon.
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Affiliation(s)
- Andrea Legati
- Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Daniele Ghezzi
- Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy.,Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy.,Lab of Neurogenetics and Mitochondrial Disorders, Fondazione IRCCS Istituto Neurologico Carlo Besta/Università degli Studi di Milano, Milan, Italy
| | - Carlo Viscomi
- Department of Biomedical Sciences, University of Padova, Padova, Italy.
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19
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Morava E, Oglesbee D. Laboratory and metabolic investigations. HANDBOOK OF CLINICAL NEUROLOGY 2023; 194:167-172. [PMID: 36813311 DOI: 10.1016/b978-0-12-821751-1.00012-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
Clinical variability and substantial overlap between mitochondrial disorders and other genetic disorders and inborn errors make the clinical and metabolic diagnosis of mitochondrial disorders quite challenging. Evaluating specific laboratory markers is essential in the diagnostic process, but mitochondrial disease can be present in the absence of any abnormal metabolic markers. In this chapter, we share the current consensus guidelines for metabolic investigations, including investigations in blood, urine, and the cerebral spinal fluid and discuss different diagnostic approaches. As personal experience might significantly vary and there are different recommendations published as diagnostic guidelines, the Mitochondrial Medicine Society developed a consensus approach based on literature review for metabolic diagnostics in a suspected mitochondrial disease. According to the guidelines, the work-up should include the assessment of complete blood count, creatine phosphokinase, transaminases, albumin, postprandial lactate and pyruvate (lactate/pyruvate ratio when the lactate level is elevated), uric acid, thymidine, amino acids, acylcarnitines in blood, and urinary organic acids (especially screening for 3-methylglutaconic acid). Urine amino acid analysis is recommended in mitochondrial tubulopathies. CSF metabolite analysis (lactate, pyruvate, amino acids, and 5-methyltetrahydrofolate) should be included in the presence of central nervous system disease. We also suggest a diagnostic strategy based on the mitochondrial disease criteria (MDC) scoring system in mitochondrial disease diagnostics; evaluating muscle-, neurologic-, and multisystem involvement, and the presence of metabolic markers and abnormal imaging. The consensus guideline encourages a primary genetic approach in diagnostics and only suggests a more invasive diagnostic approach with tissue biopsies (histology, OXPHOS measurements, etc.) after nonconclusive genetic testing.
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Affiliation(s)
- Eva Morava
- Department of Clinical Genomics, Mayo Clinic, Rochester, MN, United States; Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, United States; Department of Medical Genetics, University of Pecs Medical School, Pecs, Hungary.
| | - Devin Oglesbee
- Department of Clinical Genomics, Mayo Clinic, Rochester, MN, United States; Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, United States
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Genetics of mitochondrial diseases: Current approaches for the molecular diagnosis. HANDBOOK OF CLINICAL NEUROLOGY 2023; 194:141-165. [PMID: 36813310 DOI: 10.1016/b978-0-12-821751-1.00011-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
Mitochondrial diseases are a genetically and phenotypically variable set of monogenic disorders. The main characteristic of mitochondrial diseases is a defective oxidative phosphorylation. Both nuclear and mitochondrial DNA encode the approximately 1500 mitochondrial proteins. Since identification of the first mitochondrial disease gene in 1988 a total of 425 genes have been associated with mitochondrial diseases. Mitochondrial dysfunctions can be caused both by pathogenic variants in the mitochondrial DNA or the nuclear DNA. Hence, besides maternal inheritance, mitochondrial diseases can follow all modes of Mendelian inheritance. The maternal inheritance and tissue specificity distinguish molecular diagnostics of mitochondrial disorders from other rare disorders. With the advances made in the next-generation sequencing technology, whole exome sequencing and even whole-genome sequencing are now the established methods of choice for molecular diagnostics of mitochondrial diseases. They reach a diagnostic rate of more than 50% in clinically suspected mitochondrial disease patients. Moreover, next-generation sequencing is delivering a constantly growing number of novel mitochondrial disease genes. This chapter reviews mitochondrial and nuclear causes of mitochondrial diseases, molecular diagnostic methodologies, and their current challenges and perspectives.
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Popoiu TA, Dudek J, Maack C, Bertero E. Cardiac Involvement in Mitochondrial Disorders. Curr Heart Fail Rep 2023; 20:76-87. [PMID: 36802007 PMCID: PMC9977856 DOI: 10.1007/s11897-023-00592-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/17/2022] [Indexed: 02/21/2023]
Abstract
PURPOSE OF REVIEW We review pathophysiology and clinical features of mitochondrial disorders manifesting with cardiomyopathy. RECENT FINDINGS Mechanistic studies have shed light into the underpinnings of mitochondrial disorders, providing novel insights into mitochondrial physiology and identifying new therapeutic targets. Mitochondrial disorders are a group of rare genetic diseases that are caused by mutations in mitochondrial DNA (mtDNA) or in nuclear genes that are essential to mitochondrial function. The clinical picture is extremely heterogeneous, the onset can occur at any age, and virtually, any organ or tissue can be involved. Since the heart relies primarily on mitochondrial oxidative metabolism to fuel contraction and relaxation, cardiac involvement is common in mitochondrial disorders and often represents a major determinant of their prognosis.
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Affiliation(s)
- Tudor-Alexandru Popoiu
- Department of Translational Research, Comprehensive Heart Failure Center, University Clinic Würzburg, Wurzburg, Germany
- "Victor Babes" University of Medicine and Pharmacy, Timisoara, Romania
| | - Jan Dudek
- Department of Translational Research, Comprehensive Heart Failure Center, University Clinic Würzburg, Wurzburg, Germany
| | - Christoph Maack
- Department of Translational Research, Comprehensive Heart Failure Center, University Clinic Würzburg, Wurzburg, Germany
| | - Edoardo Bertero
- Department of Translational Research, Comprehensive Heart Failure Center, University Clinic Würzburg, Wurzburg, Germany.
- Department of Internal Medicine and Specialties (Di.M.I.), University of Genoa, Genoa, Italy.
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22
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Guerrero-Molina MP, Morales-Conejo M, Delmiro A, Morán M, Domínguez-González C, Arranz-Canales E, Ramos-González A, Arenas J, Martín MA, de la Aleja JG. High-dose oral glutamine supplementation reduces elevated glutamate levels in cerebrospinal fluid in patients with mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes syndrome. Eur J Neurol 2023; 30:538-547. [PMID: 36334048 DOI: 10.1111/ene.15626] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 10/07/2022] [Accepted: 10/27/2022] [Indexed: 11/08/2022]
Abstract
BACKGROUND AND PURPOSE Mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS) syndrome is a genetically heterogeneous disorder caused by mitochondrial DNA mutations. There are no disease-modifying therapies, and treatment remains mainly supportive. It has been shown previously that patients with MELAS syndrome have significantly increased cerebrospinal fluid (CSF) glutamate and significantly decreased CSF glutamine levels compared to controls. Glutamine has many metabolic fates in neurons and astrocytes, and the glutamate-glutamine cycle couples with many metabolic pathways depending on cellular requirements. The aim was to compare CSF glutamate and glutamine levels before and after dietary glutamine supplementation. It is postulated that high-dose oral glutamine supplementation could reduce the increase in glutamate levels. METHOD This open-label, single-cohort study determined the safety and changes in glutamate and glutamine levels in CSF after 12 weeks of oral glutamine supplementation. RESULTS Nine adult patients with MELAS syndrome (66.7% females, mean age 35.8 ± 3.2 years) were included. After glutamine supplementation, CSF glutamate levels were significantly reduced (9.77 ± 1.21 vs. 18.48 ± 1.34 μmol/l, p < 0.001) and CSF glutamine levels were significantly increased (433.66 ± 15.31 vs. 336.31 ± 12.92 μmol/l, p = 0.002). A side effect observed in four of nine patients was a mild sensation of satiety. One patient developed mild and transient elevation of transaminases, and another patient was admitted for an epileptic status without stroke-like episode. DISCUSSION This study demonstrates that high-dose oral glutamine supplementation significantly reduces CSF glutamate and increases CSF glutamine levels in patients with MELAS syndrome. These findings may have potential therapeutic implications in these patients. TRIAL REGISTRATION INFORMATION ClinicalTrials.gov Identifier: NCT04948138. Initial release 24 June 2021, first patient enrolled 1 July 2021. https://clinicaltrials.gov/ct2/show/NCT04948138.
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Affiliation(s)
| | - Montserrat Morales-Conejo
- Department of Internal Medicine, University Hospital, Madrid, Spain
- National Reference Center for Congenital Errors of Metabolism (CSUR) and European Reference Center for Inherited Metabolic Disease (MetabERN), University Hospital, Madrid, Spain
- Spanish Network for Biomedical Research in Rare Diseases (CIBERER), Madrid, Spain
| | - Aitor Delmiro
- Spanish Network for Biomedical Research in Rare Diseases (CIBERER), Madrid, Spain
- Mitochondrial and Neuromuscular Diseases Laboratory, Instituto de Investigación Sanitaria Hospital '12 de Octubre' ('imas12'), Madrid, Spain
- Research Institute ('imas12'), University Hospital, Madrid, Spain
| | - María Morán
- Spanish Network for Biomedical Research in Rare Diseases (CIBERER), Madrid, Spain
- Mitochondrial and Neuromuscular Diseases Laboratory, Instituto de Investigación Sanitaria Hospital '12 de Octubre' ('imas12'), Madrid, Spain
- Research Institute ('imas12'), University Hospital, Madrid, Spain
| | - Cristina Domínguez-González
- Neurology Department, Neuromuscular Disorders Unit, University Hospital, Madrid, Spain
- Spanish Network for Biomedical Research in Rare Diseases (CIBERER), Madrid, Spain
- Research Institute ('imas12'), University Hospital, Madrid, Spain
| | - Elena Arranz-Canales
- Department of Internal Medicine, University Hospital, Madrid, Spain
- National Reference Center for Congenital Errors of Metabolism (CSUR) and European Reference Center for Inherited Metabolic Disease (MetabERN), University Hospital, Madrid, Spain
| | | | - Joaquín Arenas
- Spanish Network for Biomedical Research in Rare Diseases (CIBERER), Madrid, Spain
- Mitochondrial and Neuromuscular Diseases Laboratory, Instituto de Investigación Sanitaria Hospital '12 de Octubre' ('imas12'), Madrid, Spain
- Research Institute ('imas12'), University Hospital, Madrid, Spain
| | - Miguel A Martín
- Spanish Network for Biomedical Research in Rare Diseases (CIBERER), Madrid, Spain
- Mitochondrial and Neuromuscular Diseases Laboratory, Instituto de Investigación Sanitaria Hospital '12 de Octubre' ('imas12'), Madrid, Spain
- Research Institute ('imas12'), University Hospital, Madrid, Spain
| | - Jesús González de la Aleja
- National Reference Center for Congenital Errors of Metabolism (CSUR) and European Reference Center for Inherited Metabolic Disease (MetabERN), University Hospital, Madrid, Spain
- Neurology Department, Epilepsy Unit, University Hospital, Madrid, Spain
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23
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Leigh Syndrome: Spectrum of Molecular Defects and Clinical Features in Russia. Int J Mol Sci 2023; 24:ijms24021597. [PMID: 36675121 PMCID: PMC9865855 DOI: 10.3390/ijms24021597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 01/03/2023] [Accepted: 01/06/2023] [Indexed: 01/15/2023] Open
Abstract
Leigh syndrome (LS), also known as infantile subacute necrotizing encephalopathy, is the most frequent mitochondrial disorder in children. Recently, more than 80 genes have been associated with LS, which greatly complicates the diagnosis. In this article, we present clinical and molecular findings of 219 patients with LS and give the detailed description of three cases with rare findings in nuclear genes MORC2, NARS2 and VPS13D, demonstrating wide genetic heterogeneity of this mitochondrial disease. The most common cause of LS in Russian patients are pathogenic variants in the SURF1 gene (44.3% of patients). The most frequent pathogenic variant is c.845_846delCT (66.0% of mutant alleles; 128/192), which is also widespread in Eastern Europe. Five main LS genes, SURF1, SCO2, MT-ATP6, MT-ND5 and PDHA1, account for 70% of all LS cases in the Russian Federation. Using next generation sequencing (NGS) technique, we were able to detect pathogenic variants in other nuclear genes: NDUFV1, NDUFS2, NDUFS8, NDUFAF5, NDUFAF6, NDUFA10, SUCLG1, GFM2, COX10, PMPCB, NARS2, PDHB and SLC19A3, including two genes previously associated with Leigh-like phenotypes-MORC2 and VPS13D. We found 49 previously undescribed nucleotide variants, including two deep intronic variants which affect splicing.
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Baker MJ, Crameri JJ, Thorburn DR, Frazier AE, Stojanovski D. Mitochondrial biology and dysfunction in secondary mitochondrial disease. Open Biol 2022; 12:220274. [PMID: 36475414 PMCID: PMC9727669 DOI: 10.1098/rsob.220274] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Mitochondrial diseases are a broad, genetically heterogeneous class of metabolic disorders characterized by deficits in oxidative phosphorylation (OXPHOS). Primary mitochondrial disease (PMD) defines pathologies resulting from mutation of mitochondrial DNA (mtDNA) or nuclear genes affecting either mtDNA expression or the biogenesis and function of the respiratory chain. Secondary mitochondrial disease (SMD) arises due to mutation of nuclear-encoded genes independent of, or indirectly influencing OXPHOS assembly and operation. Despite instances of novel SMD increasing year-on-year, PMD is much more widely discussed in the literature. Indeed, since the implementation of next generation sequencing (NGS) techniques in 2010, many novel mitochondrial disease genes have been identified, approximately half of which are linked to SMD. This review will consolidate existing knowledge of SMDs and outline discrete categories within which to better understand the diversity of SMD phenotypes. By providing context to the biochemical and molecular pathways perturbed in SMD, we hope to further demonstrate the intricacies of SMD pathologies outside of their indirect contribution to mitochondrial energy generation.
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Affiliation(s)
- Megan J. Baker
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria 3052, Australia
| | - Jordan J. Crameri
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria 3052, Australia
| | - David R. Thorburn
- Murdoch Children's Research Institute, Royal Children's Hospital and Department of Paediatrics, University of Melbourne, Parkville, Victoria 3052, Australia,Victorian Clinical Genetics Services, Royal Children's Hospital, Parkville, Victoria 3052, Australia
| | - Ann E. Frazier
- Murdoch Children's Research Institute, Royal Children's Hospital and Department of Paediatrics, University of Melbourne, Parkville, Victoria 3052, Australia
| | - Diana Stojanovski
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria 3052, Australia
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Kline BL, Jaillard S, Bell KM, Bakhshalizadeh S, Robevska G, van den Bergen J, Dulon J, Ayers KL, Christodoulou J, Tchan MC, Touraine P, Sinclair AH, Tucker EJ. Integral Role of the Mitochondrial Ribosome in Supporting Ovarian Function: MRPS7 Variants in Syndromic Premature Ovarian Insufficiency. Genes (Basel) 2022; 13:2113. [PMID: 36421788 PMCID: PMC9690861 DOI: 10.3390/genes13112113] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 11/09/2022] [Accepted: 11/11/2022] [Indexed: 10/03/2023] Open
Abstract
The mitochondrial ribosome is critical to mitochondrial protein synthesis. Defects in both the large and small subunits of the mitochondrial ribosome can cause human disease, including, but not limited to, cardiomyopathy, hypoglycaemia, neurological dysfunction, sensorineural hearing loss and premature ovarian insufficiency (POI). POI is a common cause of infertility, characterised by elevated follicle-stimulating hormone and amenorrhea in women under the age of 40. Here we describe a patient with POI, sensorineural hearing loss and Hashimoto's disease. The co-occurrence of POI with sensorineural hearing loss indicates Perrault syndrome. Whole exome sequencing identified two compound heterozygous variants in mitochondrial ribosomal protein 7 (MRPS7), c.373A>T/p.(Lys125*) and c.536G>A/p.(Arg179His). Both novel variants are predicted to be pathogenic via in-silico algorithms. Variants in MRPS7 have been described only once in the literature and were identified in sisters, one of whom presented with congenital sensorineural hearing loss and POI, consistent with our patient phenotype. The other affected sister had a more severe disease course and died in early adolescence due to liver and renal failure before the reproductive phenotype was known. This second independent report validates that variants in MRPS7 are a cause of syndromic POI/Perrault syndrome. We present this case and review the current evidence supporting the integral role of the mitochondrial ribosome in supporting ovarian function.
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Affiliation(s)
- Brianna L. Kline
- Murdoch Children’s Research Institute, Royal Children’s Hospital, Melbourne, VIC 3052, Australia
| | - Sylvie Jaillard
- IRSET (Institut de Recherche en Santé, Environnement et Travail), INSERM/EHESP/Univ Rennes/CHU Rennes–UMR_S 1085, F-35000 Rennes, France
- CHU Rennes, Service de Cytogénétique et Biologie Cellulaire, F-35033 Rennes, France
| | - Katrina M. Bell
- Murdoch Children’s Research Institute, Royal Children’s Hospital, Melbourne, VIC 3052, Australia
| | - Shabnam Bakhshalizadeh
- Murdoch Children’s Research Institute, Royal Children’s Hospital, Melbourne, VIC 3052, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, VIC 3052, Australia
| | - Gorjana Robevska
- Murdoch Children’s Research Institute, Royal Children’s Hospital, Melbourne, VIC 3052, Australia
| | - Jocelyn van den Bergen
- Murdoch Children’s Research Institute, Royal Children’s Hospital, Melbourne, VIC 3052, Australia
| | - Jérôme Dulon
- Department of Endocrinology and Reproductive Medicine, AP-HP, Sorbonne University Medicine, Centre de Référence des Maladies Endocriniennes Rares de la Croissance et du Développement, Centre des Pathologies Gynécologiques Rares, 75231 Paris, France
| | - Katie L. Ayers
- Murdoch Children’s Research Institute, Royal Children’s Hospital, Melbourne, VIC 3052, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, VIC 3052, Australia
| | - John Christodoulou
- Murdoch Children’s Research Institute, Royal Children’s Hospital, Melbourne, VIC 3052, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, VIC 3052, Australia
| | - Michel C. Tchan
- Department of Genetic Medicine, Westmead Hospital, Sydney, NSW 2145, Australia
| | - Philippe Touraine
- Department of Endocrinology and Reproductive Medicine, AP-HP, Sorbonne University Medicine, Centre de Référence des Maladies Endocriniennes Rares de la Croissance et du Développement, Centre des Pathologies Gynécologiques Rares, 75231 Paris, France
| | - Andrew H. Sinclair
- Murdoch Children’s Research Institute, Royal Children’s Hospital, Melbourne, VIC 3052, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, VIC 3052, Australia
| | - Elena J. Tucker
- Murdoch Children’s Research Institute, Royal Children’s Hospital, Melbourne, VIC 3052, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, VIC 3052, Australia
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Lopriore P, Gomes F, Montano V, Siciliano G, Mancuso M. Mitochondrial Epilepsy, a Challenge for Neurologists. Int J Mol Sci 2022; 23:ijms232113216. [PMID: 36362003 PMCID: PMC9656379 DOI: 10.3390/ijms232113216] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Revised: 10/26/2022] [Accepted: 10/27/2022] [Indexed: 01/29/2023] Open
Abstract
Primary mitochondrial diseases are relatively common inborn errors of energy metabolism, with a combined prevalence of 1 in 4300. These disorders typically affect tissues with high energy requirements, including the brain. Epilepsy affects >1% of the worldwide population, making it one of the most common neurological illnesses; it may be the presenting feature of a mitochondrial disease, but is often part of a multisystem clinical presentation. The major genetic causes of mitochondrial epilepsy are mutations in mitochondrial DNA and in the nuclear-encoded gene POLG. Treatment of mitochondrial epilepsy may be challenging, often representing a poor prognostic feature. This narrative review will cover the most recent advances in the field of mitochondrial epilepsy, from pathophysiology and genetic etiologies to phenotype and treatment options.
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Affiliation(s)
- Piervito Lopriore
- Neurological Institute, Department of Clinical and Experimental Medicine, University of Pisa, 56126 Pisa, Italy
| | - Fábio Gomes
- Neurology Department, Coimbra University Hospital Centre, 3004-561 Coimbra, Portugal
| | - Vincenzo Montano
- Neurological Institute, Department of Clinical and Experimental Medicine, University of Pisa, 56126 Pisa, Italy
| | - Gabriele Siciliano
- Neurological Institute, Department of Clinical and Experimental Medicine, University of Pisa, 56126 Pisa, Italy
| | - Michelangelo Mancuso
- Neurological Institute, Department of Clinical and Experimental Medicine, University of Pisa, 56126 Pisa, Italy
- Correspondence:
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27
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De Paepe B. The Cytokine Growth Differentiation Factor-15 and Skeletal Muscle Health: Portrait of an Emerging Widely Applicable Disease Biomarker. Int J Mol Sci 2022; 23:ijms232113180. [PMID: 36361969 PMCID: PMC9654287 DOI: 10.3390/ijms232113180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 10/21/2022] [Accepted: 10/26/2022] [Indexed: 12/04/2022] Open
Abstract
Growth differentiation factor 15 (GDF-15) is a stress-induced transforming growth factor-β superfamily cytokine with versatile functions in human health. Elevated GDF-15 blood levels associate with multiple pathological conditions, and are currently extensively explored for diagnosis, and as a means to monitor disease progression and evaluate therapeutic responses. This review analyzes GDF-15 in human conditions specifically focusing on its association with muscle manifestations of sarcopenia, mitochondrial myopathy, and autoimmune and viral myositis. The use of GDF-15 as a widely applicable health biomarker to monitor muscle disease is discussed, and its potential as a therapeutic target is explored.
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Affiliation(s)
- Boel De Paepe
- Neuromuscular Reference Center, Ghent University Hospital, Corneel Heymanslaan 10, 9000 Ghent, Belgium
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28
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Tanaka M, Szabó Á, Spekker E, Polyák H, Tóth F, Vécsei L. Mitochondrial Impairment: A Common Motif in Neuropsychiatric Presentation? The Link to the Tryptophan-Kynurenine Metabolic System. Cells 2022; 11:cells11162607. [PMID: 36010683 PMCID: PMC9406499 DOI: 10.3390/cells11162607] [Citation(s) in RCA: 44] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 08/14/2022] [Accepted: 08/19/2022] [Indexed: 02/07/2023] Open
Abstract
Nearly half a century has passed since the discovery of cytoplasmic inheritance of human chloramphenicol resistance. The inheritance was then revealed to take place maternally by mitochondrial DNA (mtDNA). Later, a number of mutations in mtDNA were identified as a cause of severe inheritable metabolic diseases with neurological manifestation, and the impairment of mitochondrial functions has been probed in the pathogenesis of a wide range of illnesses including neurodegenerative diseases. Recently, a growing number of preclinical studies have revealed that animal behaviors are influenced by the impairment of mitochondrial functions and possibly by the loss of mitochondrial stress resilience. Indeed, as high as 54% of patients with one of the most common primary mitochondrial diseases, mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS) syndrome, present psychiatric symptoms including cognitive impairment, mood disorder, anxiety, and psychosis. Mitochondria are multifunctional organelles which produce cellular energy and play a major role in other cellular functions including homeostasis, cellular signaling, and gene expression, among others. Mitochondrial functions are observed to be compromised and to become less resilient under continuous stress. Meanwhile, stress and inflammation have been linked to the activation of the tryptophan (Trp)-kynurenine (KYN) metabolic system, which observably contributes to the development of pathological conditions including neurological and psychiatric disorders. This review discusses the functions of mitochondria and the Trp-KYN system, the interaction of the Trp-KYN system with mitochondria, and the current understanding of the involvement of mitochondria and the Trp-KYN system in preclinical and clinical studies of major neurological and psychiatric diseases.
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Affiliation(s)
- Masaru Tanaka
- ELKH-SZTE Neuroscience Research Group, Danube Neuroscience Research Laboratory, Eötvös Loránd Research Network, University of Szeged (ELKH-SZTE), Tisza Lajos krt. 113, H-6725 Szeged, Hungary
| | - Ágnes Szabó
- Department of Neurology, Albert Szent-Györgyi Medical School, University of Szeged, Semmelweis u. 6, H-6725 Szeged, Hungary
- Doctoral School of Clinical Medicine, University of Szeged, Korányi fasor 6, H-6720 Szeged, Hungary
| | - Eleonóra Spekker
- ELKH-SZTE Neuroscience Research Group, Danube Neuroscience Research Laboratory, Eötvös Loránd Research Network, University of Szeged (ELKH-SZTE), Tisza Lajos krt. 113, H-6725 Szeged, Hungary
| | - Helga Polyák
- Department of Neurology, Albert Szent-Györgyi Medical School, University of Szeged, Semmelweis u. 6, H-6725 Szeged, Hungary
- Doctoral School of Clinical Medicine, University of Szeged, Korányi fasor 6, H-6720 Szeged, Hungary
| | - Fanni Tóth
- ELKH-SZTE Neuroscience Research Group, Danube Neuroscience Research Laboratory, Eötvös Loránd Research Network, University of Szeged (ELKH-SZTE), Tisza Lajos krt. 113, H-6725 Szeged, Hungary
| | - László Vécsei
- ELKH-SZTE Neuroscience Research Group, Danube Neuroscience Research Laboratory, Eötvös Loránd Research Network, University of Szeged (ELKH-SZTE), Tisza Lajos krt. 113, H-6725 Szeged, Hungary
- Department of Neurology, Albert Szent-Györgyi Medical School, University of Szeged, Semmelweis u. 6, H-6725 Szeged, Hungary
- Correspondence: ; Tel.: +36-62-545-351
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Dzinovic I, Winkelmann J, Zech M. Genetic intersection between dystonia and neurodevelopmental disorders: Insights from genomic sequencing. Parkinsonism Relat Disord 2022; 102:131-140. [DOI: 10.1016/j.parkreldis.2022.08.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 08/12/2022] [Accepted: 08/18/2022] [Indexed: 10/15/2022]
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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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Rahman MM, Young CKJ, Goffart S, Pohjoismäki JLO, Young MJ. Heterozygous p.Y955C mutation in DNA polymerase γ leads to alterations in bioenergetics, complex I subunit expression, and mtDNA replication. J Biol Chem 2022; 298:102196. [PMID: 35760101 PMCID: PMC9307957 DOI: 10.1016/j.jbc.2022.102196] [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: 01/23/2022] [Revised: 06/16/2022] [Accepted: 06/17/2022] [Indexed: 12/03/2022] Open
Abstract
In human cells, ATP is generated using oxidative phosphorylation machinery, which is inoperable without proteins encoded by mitochondrial DNA (mtDNA). The DNA polymerase gamma (Polγ) repairs and replicates the multicopy mtDNA genome in concert with additional factors. The Polγ catalytic subunit is encoded by the POLG gene, and mutations in this gene cause mtDNA genome instability and disease. Barriers to studying the molecular effects of disease mutations include scarcity of patient samples and a lack of available mutant models; therefore, we developed a human SJCRH30 myoblast cell line model with the most common autosomal dominant POLG mutation, c.2864A>G/p.Y955C, as individuals with this mutation can present with progressive skeletal muscle weakness. Using on-target sequencing, we detected a 50% conversion frequency of the mutation, confirming heterozygous Y955C substitution. We found mutated cells grew slowly in a glucose-containing medium and had reduced mitochondrial bioenergetics compared with the parental cell line. Furthermore, growing Y955C cells in a galactose-containing medium to obligate mitochondrial function enhanced these bioenergetic deficits. Also, we show complex I NDUFB8 and ND3 protein levels were decreased in the mutant cell line, and the maintenance of mtDNA was severely impaired (i.e., lower copy number, fewer nucleoids, and an accumulation of Y955C-specific replication intermediates). Finally, we show the mutant cells have increased sensitivity to the mitochondrial toxicant 2′-3′-dideoxycytidine. We expect this POLG Y955C cell line to be a robust system to identify new mitochondrial toxicants and therapeutics to treat mitochondrial dysfunction.
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Affiliation(s)
- Md Mostafijur Rahman
- Department of Biochemistry and Molecular Biology, Southern Illinois University School of Medicine, Carbondale, Illinois 62901
| | - Carolyn K J Young
- Department of Biochemistry and Molecular Biology, Southern Illinois University School of Medicine, Carbondale, Illinois 62901
| | - Steffi Goffart
- Department of Environmental and Biological Sciences, University of Eastern Finland, 80101 Joensuu, Finland
| | - Jaakko L O Pohjoismäki
- Department of Environmental and Biological Sciences, University of Eastern Finland, 80101 Joensuu, Finland
| | - Matthew J Young
- Department of Biochemistry and Molecular Biology, Southern Illinois University School of Medicine, Carbondale, Illinois 62901.
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Rensvold JW, Shishkova E, Sverchkov Y, Miller IJ, Cetinkaya A, Pyle A, Manicki M, Brademan DR, Alanay Y, Raiman J, Jochem A, Hutchins PD, Peters SR, Linke V, Overmyer KA, Salome AZ, Hebert AS, Vincent CE, Kwiecien NW, Rush MJP, Westphall MS, Craven M, Akarsu NA, Taylor RW, Coon JJ, Pagliarini DJ. Defining mitochondrial protein functions through deep multiomic profiling. Nature 2022; 606:382-388. [PMID: 35614220 PMCID: PMC9310563 DOI: 10.1038/s41586-022-04765-3] [Citation(s) in RCA: 46] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 04/14/2022] [Indexed: 11/08/2022]
Abstract
Mitochondria are epicentres of eukaryotic metabolism and bioenergetics. Pioneering efforts in recent decades have established the core protein componentry of these organelles1 and have linked their dysfunction to more than 150 distinct disorders2,3. Still, hundreds of mitochondrial proteins lack clear functions4, and the underlying genetic basis for approximately 40% of mitochondrial disorders remains unresolved5. Here, to establish a more complete functional compendium of human mitochondrial proteins, we profiled more than 200 CRISPR-mediated HAP1 cell knockout lines using mass spectrometry-based multiomics analyses. This effort generated approximately 8.3 million distinct biomolecule measurements, providing a deep survey of the cellular responses to mitochondrial perturbations and laying a foundation for mechanistic investigations into protein function. Guided by these data, we discovered that PIGY upstream open reading frame (PYURF) is an S-adenosylmethionine-dependent methyltransferase chaperone that supports both complex I assembly and coenzyme Q biosynthesis and is disrupted in a previously unresolved multisystemic mitochondrial disorder. We further linked the putative zinc transporter SLC30A9 to mitochondrial ribosomes and OxPhos integrity and established RAB5IF as the second gene harbouring pathogenic variants that cause cerebrofaciothoracic dysplasia. Our data, which can be explored through the interactive online MITOMICS.app resource, suggest biological roles for many other orphan mitochondrial proteins that still lack robust functional characterization and define a rich cell signature of mitochondrial dysfunction that can support the genetic diagnosis of mitochondrial diseases.
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Affiliation(s)
- Jarred W Rensvold
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO, USA
- Morgridge Institute for Research, Madison, WI, USA
| | - Evgenia Shishkova
- National Center for Quantitative Biology of Complex Systems, Madison, WI, USA
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - Yuriy Sverchkov
- Department of Biostatistics and Medical Informatics, University of Wisconsin-Madison, Madison, WI, USA
| | - Ian J Miller
- National Center for Quantitative Biology of Complex Systems, Madison, WI, USA
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - Arda Cetinkaya
- Department of Medical Genetics, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Angela Pyle
- Wellcome Centre for Mitochondrial Research, Newcastle University, Newcastle upon Tyne, UK
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Mateusz Manicki
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO, USA
- Morgridge Institute for Research, Madison, WI, USA
| | - Dain R Brademan
- Morgridge Institute for Research, Madison, WI, USA
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI, USA
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - Yasemin Alanay
- Department of Pediatrics, Pediatric Genetics Unit, Faculty of Medicine, Hacettepe University, Ankara, Turkey
- Department of Pediatrics, Pediatric Genetics Unit, School of Medicine, Acibadem Mehmet Ali Aydinlar University, Istanbul, Turkey
| | - Julian Raiman
- Department of Clinical Inherited Metabolic Disorders, Birmingham Women's and Children's Hospital NHS Trust, Birmingham, UK
| | - Adam Jochem
- Morgridge Institute for Research, Madison, WI, USA
| | - Paul D Hutchins
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - Sean R Peters
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - Vanessa Linke
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - Katherine A Overmyer
- Morgridge Institute for Research, Madison, WI, USA
- National Center for Quantitative Biology of Complex Systems, Madison, WI, USA
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - Austin Z Salome
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - Alexander S Hebert
- National Center for Quantitative Biology of Complex Systems, Madison, WI, USA
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - Catherine E Vincent
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - Nicholas W Kwiecien
- National Center for Quantitative Biology of Complex Systems, Madison, WI, USA
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - Matthew J P Rush
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - Michael S Westphall
- National Center for Quantitative Biology of Complex Systems, Madison, WI, USA
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - Mark Craven
- Department of Biostatistics and Medical Informatics, University of Wisconsin-Madison, Madison, WI, USA
| | - Nurten A Akarsu
- Department of Medical Genetics, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Robert W Taylor
- Wellcome Centre for Mitochondrial Research, Newcastle University, Newcastle upon Tyne, UK
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
- NHS Highly Specialised Services for Rare Mitochondrial Disorders, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Joshua J Coon
- Morgridge Institute for Research, Madison, WI, USA.
- National Center for Quantitative Biology of Complex Systems, Madison, WI, USA.
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI, USA.
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, USA.
| | - David J Pagliarini
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO, USA.
- Morgridge Institute for Research, Madison, WI, USA.
- National Center for Quantitative Biology of Complex Systems, Madison, WI, USA.
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO, USA.
- Department of Genetics, Washington University School of Medicine, St. Louis, MO, USA.
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA.
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Smeitink J, van Maanen R, de Boer L, Ruiterkamp G, Renkema H. A randomised placebo-controlled, double-blind phase II study to explore the safety, efficacy, and pharmacokinetics of sonlicromanol in children with genetically confirmed mitochondrial disease and motor symptoms ("KHENERGYC"). BMC Neurol 2022; 22:158. [PMID: 35477351 PMCID: PMC9044835 DOI: 10.1186/s12883-022-02685-3] [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: 02/01/2022] [Accepted: 04/18/2022] [Indexed: 11/21/2022] Open
Abstract
Background Methods The KHENERGYC trial will be a phase II, randomised, double-blinded, placebo-controlled (DBPC), parallel-group study in the paediatric population (birth up to and including 17 years). The study will be recruiting 24 patients suffering from motor symptoms due to genetically confirmed PMD. The trial will be divided into two phases. The first phase of the study will be an adaptive pharmacokinetic (PK) study with four days of treatment, while the second phase will include randomisation of the participants and evaluating the efficacy and safety of sonlicromanol over 6 months. Discussion Effective novel therapies for treating PMDs in children are an unmet need. This study will assess the pharmacokinetics, efficacy, and safety of sonlicromanol in children with genetically confirmed PMDs, suffering from motor symptoms. Trial registration clinicaltrials.gov: NCT04846036, registered April 15, 2021. European Union Clinical Trial Register (EUDRACT number: 2020–003124-16), registered October 20, 2020. CCMO registration: NL75221.091.20, registered on October 7, 2020.
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Affiliation(s)
- Jan Smeitink
- Khondrion BV, Transistorweg 5C, M Building, 6534, AT, Nijmegen, The Netherlands.
| | - Rob van Maanen
- Khondrion BV, Transistorweg 5C, M Building, 6534, AT, Nijmegen, The Netherlands
| | - Lonneke de Boer
- Radboud Center for Mitochondrial Medicine, Department of Pediatrics, Radboud University Medical Center Nijmegen, Geert Grooteplein Zuid 10, 6500 HB, Nijmegen, The Netherlands
| | - Gerrit Ruiterkamp
- Khondrion BV, Transistorweg 5C, M Building, 6534, AT, Nijmegen, The Netherlands
| | - Herma Renkema
- Khondrion BV, Transistorweg 5C, M Building, 6534, AT, Nijmegen, The Netherlands
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Lopriore P, Ricciarini V, Siciliano G, Mancuso M, Montano V. Mitochondrial Ataxias: Molecular Classification and Clinical Heterogeneity. Neurol Int 2022; 14:337-356. [PMID: 35466209 PMCID: PMC9036286 DOI: 10.3390/neurolint14020028] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 03/26/2022] [Accepted: 03/28/2022] [Indexed: 01/25/2023] Open
Abstract
Ataxia is increasingly being recognized as a cardinal manifestation in primary mitochondrial diseases (PMDs) in both paediatric and adult patients. It can be caused by disruption of cerebellar nuclei or fibres, its connection with the brainstem, or spinal and peripheral lesions leading to proprioceptive loss. Despite mitochondrial ataxias having no specific defining features, they should be included in hereditary ataxias differential diagnosis, given the high prevalence of PMDs. This review focuses on the clinical and neuropathological features and genetic background of PMDs in which ataxia is a prominent manifestation.
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Use of Next-Generation Sequencing for Identifying Mitochondrial Disorders. Curr Issues Mol Biol 2022; 44:1127-1148. [PMID: 35723297 PMCID: PMC8947152 DOI: 10.3390/cimb44030074] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 02/18/2022] [Accepted: 02/24/2022] [Indexed: 12/06/2022] Open
Abstract
Mitochondria are major contributors to ATP synthesis, generating more than 90% of the total cellular energy production through oxidative phosphorylation (OXPHOS): metabolite oxidation, such as the β-oxidation of fatty acids, and the Krebs’s cycle. OXPHOS inadequacy due to large genetic lesions in mitochondrial as well as nuclear genes and homo- or heteroplasmic point mutations in mitochondrially encoded genes is a characteristic of heterogeneous, maternally inherited genetic disorders known as mitochondrial disorders that affect multisystemic tissues and organs with high energy requirements, resulting in various signs and symptoms. Several traditional diagnostic approaches, including magnetic resonance imaging of the brain, cardiac testing, biochemical screening, variable heteroplasmy genetic testing, identifying clinical features, and skeletal muscle biopsies, are associated with increased risks, high costs, a high degree of false-positive or false-negative results, or a lack of precision, which limits their diagnostic abilities for mitochondrial disorders. Variable heteroplasmy levels, mtDNA depletion, and the identification of pathogenic variants can be detected through genetic sequencing, including the gold standard Sanger sequencing. However, sequencing can be time consuming, and Sanger sequencing can result in the missed recognition of larger structural variations such as CNVs or copy-number variations. Although each sequencing method has its own limitations, genetic sequencing can be an alternative to traditional diagnostic methods. The ever-growing roster of possible mutations has led to the development of next-generation sequencing (NGS). The enhancement of NGS methods can offer a precise diagnosis of the mitochondrial disorder within a short period at a reasonable expense for both research and clinical applications.
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36
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Zech M, Kopajtich R, Steinbrücker K, Bris C, Gueguen N, Feichtinger RG, Achleitner MT, Duzkale N, Périvier M, Koch J, Engelhardt H, Freisinger P, Wagner M, Brunet T, Berutti R, Smirnov D, Navaratnarajah T, Rodenburg RJ, Pais LS, Austin-Tse C, O’Leary M, Boesch S, Jech R, Bakhtiari S, Jin SC, Wilbert F, Kruer MC, Wortmann SB, Eckenweiler M, Mayr JA, Distelmaier F, Steinfeld R, Winkelmann J, Prokisch H. Variants in Mitochondrial ATP Synthase Cause Variable Neurologic Phenotypes. Ann Neurol 2022; 91:225-237. [PMID: 34954817 PMCID: PMC9939050 DOI: 10.1002/ana.26293] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 12/23/2021] [Accepted: 12/24/2021] [Indexed: 11/10/2022]
Abstract
OBJECTIVE ATP synthase (ATPase) is responsible for the majority of ATP production. Nevertheless, disease phenotypes associated with mutations in ATPase subunits are extremely rare. We aimed at expanding the spectrum of ATPase-related diseases. METHODS Whole-exome sequencing in cohorts with 2,962 patients diagnosed with mitochondrial disease and/or dystonia and international collaboration were used to identify deleterious variants in ATPase-encoding genes. Findings were complemented by transcriptional and proteomic profiling of patient fibroblasts. ATPase integrity and activity were assayed using cells and tissues from 5 patients. RESULTS We present 10 total individuals with biallelic or de novo monoallelic variants in nuclear ATPase subunit genes. Three unrelated patients showed the same homozygous missense ATP5F1E mutation (including one published case). An intronic splice-disrupting alteration in compound heterozygosity with a nonsense variant in ATP5PO was found in one patient. Three patients had de novo heterozygous missense variants in ATP5F1A, whereas another 3 were heterozygous for ATP5MC3 de novo missense changes. Bioinformatics methods and populational data supported the variants' pathogenicity. Immunohistochemistry, proteomics, and/or immunoblotting revealed significantly reduced ATPase amounts in association to ATP5F1E and ATP5PO mutations. Diminished activity and/or defective assembly of ATPase was demonstrated by enzymatic assays and/or immunoblotting in patient samples bearing ATP5F1A-p.Arg207His, ATP5MC3-p.Gly79Val, and ATP5MC3-p.Asn106Lys. The associated clinical profiles were heterogeneous, ranging from hypotonia with spontaneous resolution (1/10) to epilepsy with early death (1/10) or variable persistent abnormalities, including movement disorders, developmental delay, intellectual disability, hyperlactatemia, and other neurologic and systemic features. Although potentially reflecting an ascertainment bias, dystonia was common (7/10). INTERPRETATION Our results establish evidence for a previously unrecognized role of ATPase nuclear-gene defects in phenotypes characterized by neurodevelopmental and neurodegenerative features. ANN NEUROL 2022;91:225-237.
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Affiliation(s)
- Michael Zech
- Technical University of Munich, Munich, Germany; School of Medicine, Institute of Human Genetics,Institute of Neurogenomics, Helmholtz Zentrum München, Munich, Germany
| | - Robert Kopajtich
- Technical University of Munich, Munich, Germany; School of Medicine, Institute of Human Genetics,Institute of Neurogenomics, Helmholtz Zentrum München, Munich, Germany
| | - Katja Steinbrücker
- University Children's Hospital, Paracelsus Medical University (PMU), Salzburg, Austria
| | - Céline Bris
- Unité Mixte de Recherche MITOVASC, CNRS 6015/INSERM 1083, Université d'Angers, Angers, France,Département de Biochimie et Génétique, Centre Hospitalier Universitaire d'Angers, Angers, France
| | - Naig Gueguen
- Unité Mixte de Recherche MITOVASC, CNRS 6015/INSERM 1083, Université d'Angers, Angers, France,Département de Biochimie et Génétique, Centre Hospitalier Universitaire d'Angers, Angers, France
| | - René G. Feichtinger
- University Children's Hospital, Paracelsus Medical University (PMU), Salzburg, Austria
| | - Melanie T. Achleitner
- University Children's Hospital, Paracelsus Medical University (PMU), Salzburg, Austria
| | - Neslihan Duzkale
- Department of Medical Genetic, Diskapi Yildirim Beyazit Training and Research Hospital, Ankara, Turkey
| | | | - Johannes Koch
- University Children's Hospital, Paracelsus Medical University (PMU), Salzburg, Austria
| | - Harald Engelhardt
- Kinderkrankenhaus St. Marien gGmbH, Zentrum für Kinder- und Jugendmedizin, Landshut, Germany
| | | | - Matias Wagner
- Technical University of Munich, Munich, Germany; School of Medicine, Institute of Human Genetics,Institute of Neurogenomics, Helmholtz Zentrum München, Munich, Germany
| | - Theresa Brunet
- Technical University of Munich, Munich, Germany; School of Medicine, Institute of Human Genetics,Institute of Neurogenomics, Helmholtz Zentrum München, Munich, Germany
| | - Riccardo Berutti
- Technical University of Munich, Munich, Germany; School of Medicine, Institute of Human Genetics,Institute of Neurogenomics, Helmholtz Zentrum München, Munich, Germany
| | - Dmitrii Smirnov
- Technical University of Munich, Munich, Germany; School of Medicine, Institute of Human Genetics,Institute of Neurogenomics, Helmholtz Zentrum München, Munich, Germany
| | - Tharsini Navaratnarajah
- Department of General Pediatrics, Neonatology and Pediatric Cardiology, University Children's Hospital, Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany
| | - Richard J.T. Rodenburg
- Radboud Centre for Mitochondrial Medicine, Department of Paediatrics Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen Medical Centre Nijmegen, The Netherlands
| | - Lynn S Pais
- Program in Medical and Population Genetics, Broad Institute, Cambridge, Massachusetts, USA
| | - Christina Austin-Tse
- Harvard Medical School & Center for Genomic Medicine, Massachusetts General Hospital, Boston & Laboratory for Molecular Medicine, Partners Healthcare Personalized Medicine, Cambridge, MA
| | - Melanie O’Leary
- Broad Center for Mendelian Genomics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Sylvia Boesch
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Robert Jech
- Department of Neurology, Charles University, 1st Faculty of Medicine and General University Hospital in Prague, Prague, Czech Republic
| | - Somayeh Bakhtiari
- Pediatric Movement Disorders Program, Division of Pediatric Neurology, Barrow Neurological Institute, Phoenix Children's Hospital, Phoenix, Arizona, USA,Departments of Child Health, Neurology, and Cellular & Molecular Medicine, and Program in Genetics, University of Arizona College of Medicine-Phoenix, Phoenix, Arizona, USA
| | - Sheng Chih Jin
- Department of Genetics, Washington University School of Medicine, St Louis, Missouri, USA,Department of Pediatrics, Washington University School of Medicine, St Louis, Missouri, USA
| | - Friederike Wilbert
- Department of Neuropediatrics and Muscle Disorders, University Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Michael C Kruer
- Pediatric Movement Disorders Program, Division of Pediatric Neurology, Barrow Neurological Institute, Phoenix Children's Hospital, Phoenix, Arizona, USA,Departments of Child Health, Neurology, and Cellular & Molecular Medicine, and Program in Genetics, University of Arizona College of Medicine-Phoenix, Phoenix, Arizona, USA
| | - Saskia B. Wortmann
- University Children's Hospital, Paracelsus Medical University (PMU), Salzburg, Austria,Radboud Center for Mitochondrial Medicine, Department of Pediatrics, Amalia Children's Hospital, Radboudumc, Nijmegen, The Netherlands
| | - Matthias Eckenweiler
- Department of Neuropediatrics and Muscle Disorders, University Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Johannes A. Mayr
- University Children's Hospital, Paracelsus Medical University (PMU), Salzburg, Austria
| | - Felix Distelmaier
- Department of General Pediatrics, Neonatology and Pediatric Cardiology, University Children's Hospital, Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany
| | - Robert Steinfeld
- Department of Pediatric Neurology, University Children's Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Juliane Winkelmann
- Technical University of Munich, Munich, Germany; School of Medicine, Institute of Human Genetics,Institute of Neurogenomics, Helmholtz Zentrum München, Munich, Germany,Lehrstuhl für Neurogenetik, Technische Universität München, Munich, Germany,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Holger Prokisch
- Technical University of Munich, Munich, Germany; School of Medicine, Institute of Human Genetics,Institute of Neurogenomics, Helmholtz Zentrum München, Munich, Germany
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Valiente-Pallejà A, Tortajada J, Bulduk BK, Vilella E, Garrabou G, Muntané G, Martorell L. Comprehensive summary of mitochondrial DNA alterations in the postmortem human brain: A systematic review. EBioMedicine 2022; 76:103815. [PMID: 35085849 PMCID: PMC8790490 DOI: 10.1016/j.ebiom.2022.103815] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 12/24/2021] [Accepted: 01/05/2022] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Mitochondrial DNA (mtDNA) encodes 37 genes necessary for synthesizing 13 essential subunits of the oxidative phosphorylation system. mtDNA alterations are known to cause mitochondrial disease (MitD), a clinically heterogeneous group of disorders that often present with neuropsychiatric symptoms. Understanding the nature and frequency of mtDNA alterations in health and disease could be a cornerstone in disentangling the relationship between biochemical findings and clinical symptoms of brain disorders. This systematic review aimed to summarize the mtDNA alterations in human brain tissue reported to date that have implications for further research on the pathophysiological significance of mtDNA alterations in brain functioning. METHODS We searched the PubMed and Embase databases using distinct terms related to postmortem human brain and mtDNA up to June 10, 2021. Reports were eligible if they were empirical studies analysing mtDNA in postmortem human brains. FINDINGS A total of 158 of 637 studies fulfilled the inclusion criteria and were clustered into the following groups: MitD (48 entries), neurological diseases (NeuD, 55 entries), psychiatric diseases (PsyD, 15 entries), a miscellaneous group with controls and other clinical diseases (5 entries), ageing (20 entries), and technical issues (5 entries). Ten entries were ascribed to more than one group. Pathogenic single nucleotide variants (pSNVs), both homo- or heteroplasmic variants, have been widely reported in MitD, with heteroplasmy levels varying among brain regions; however, pSNVs are rarer in NeuD, PsyD and ageing. A lower mtDNA copy number (CN) in disease was described in most, but not all, of the identified studies. mtDNA deletions were identified in individuals in the four clinical categories and ageing. Notably, brain samples showed significantly more mtDNA deletions and at higher heteroplasmy percentages than blood samples, and several of the deletions present in the brain were not detected in the blood. Finally, mtDNA heteroplasmy, mtDNA CN and the deletion levels varied depending on the brain region studied. INTERPRETATION mtDNA alterations are well known to affect human tissues, including the brain. In general, we found that studies of MitD, NeuD, PsyD, and ageing were highly variable in terms of the type of disease or ageing process investigated, number of screened individuals, studied brain regions and technology used. In NeuD and PsyD, no particular type of mtDNA alteration could be unequivocally assigned to any specific disease or diagnostic group. However, the presence of mtDNA deletions and mtDNA CN variation imply a role for mtDNA in NeuD and PsyD. Heteroplasmy levels and threshold effects, affected brain regions, and mitotic segregation patterns of mtDNA alterations may be involved in the complex inheritance of NeuD and PsyD and in the ageing process. Therefore, more information is needed regarding the type of mtDNA alteration, the affected brain regions, the heteroplasmy levels, and their relationship with clinical phenotypes and the ageing process. FUNDING Hospital Universitari Institut Pere Mata; Institut d'Investigació Sanitària Pere Virgili; Instituto de Salud Carlos III, Ministerio de Ciencia e Innovación (PI18/00514).
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Affiliation(s)
- Alba Valiente-Pallejà
- Research Department, Hospital Universitari Institut Pere Mata (HUIPM); Institut d'Investigació Sanitària Pere Virgili (IISPV); Faculty of Medicine and Health Sciences, Universitat Rovira i Virgili (URV), 43201 Reus, Catalonia, Spain; Biomedical Network Research Centre on Mental Health (CIBERSAM), 28029 Madrid, Spain
| | - Juan Tortajada
- Research Department, Hospital Universitari Institut Pere Mata (HUIPM); Institut d'Investigació Sanitària Pere Virgili (IISPV); Faculty of Medicine and Health Sciences, Universitat Rovira i Virgili (URV), 43201 Reus, Catalonia, Spain; Biomedical Network Research Centre on Mental Health (CIBERSAM), 28029 Madrid, Spain
| | - Bengisu K Bulduk
- Research Department, Hospital Universitari Institut Pere Mata (HUIPM); Institut d'Investigació Sanitària Pere Virgili (IISPV); Faculty of Medicine and Health Sciences, Universitat Rovira i Virgili (URV), 43201 Reus, Catalonia, Spain; Biomedical Network Research Centre on Mental Health (CIBERSAM), 28029 Madrid, Spain
| | - Elisabet Vilella
- Research Department, Hospital Universitari Institut Pere Mata (HUIPM); Institut d'Investigació Sanitària Pere Virgili (IISPV); Faculty of Medicine and Health Sciences, Universitat Rovira i Virgili (URV), 43201 Reus, Catalonia, Spain; Biomedical Network Research Centre on Mental Health (CIBERSAM), 28029 Madrid, Spain
| | - Glòria Garrabou
- Laboratory of Muscle Research and Mitochondrial Function, Department of Internal Medicine-Hospital Clínic of Barcelona (HCB); Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS); Faculty of Medicine and Health Sciences, Universitat de Barcelona (UB), 08036 Barcelona, Catalonia, Spain; Biomedical Network Research Centre on Rare Diseases (CIBERER), 28029 Madrid, Spain
| | - Gerard Muntané
- Research Department, Hospital Universitari Institut Pere Mata (HUIPM); Institut d'Investigació Sanitària Pere Virgili (IISPV); Faculty of Medicine and Health Sciences, Universitat Rovira i Virgili (URV), 43201 Reus, Catalonia, Spain; Biomedical Network Research Centre on Mental Health (CIBERSAM), 28029 Madrid, Spain; Institute of Evolutionary Biology (IBE), Universitat Pompeu Fabra (UPF), 08003 Barcelona, Catalonia, Spain
| | - Lourdes Martorell
- Research Department, Hospital Universitari Institut Pere Mata (HUIPM); Institut d'Investigació Sanitària Pere Virgili (IISPV); Faculty of Medicine and Health Sciences, Universitat Rovira i Virgili (URV), 43201 Reus, Catalonia, Spain; Biomedical Network Research Centre on Mental Health (CIBERSAM), 28029 Madrid, Spain.
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Stenton SL, Zou Y, Cheng H, Liu Z, Wang J, Shen D, Jin H, Ding C, Tang X, Sun S, Han H, Ma Y, Zhang W, Jin R, Wang H, Sun D, Lv JL, Prokisch H, Fang F. Leigh syndrome: a study of 209 patients at the Beijing Children's Hospital. Ann Neurol 2022; 91:466-482. [PMID: 35094435 DOI: 10.1002/ana.26313] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 01/25/2022] [Accepted: 01/27/2022] [Indexed: 11/12/2022]
Affiliation(s)
- Sarah L. Stenton
- Institute of Human Genetics, School of Medicine Technical University of Munich Munich Germany
- Institute of Neurogenomics Helmholtz Zentrum München Neuherberg Germany
| | - Ying Zou
- Department of Neurology, National Center for Children's Health, Beijing Children's Hospital Capital Medical University Beijing China
| | - Hua Cheng
- Image Center, National Center for Children's Health, Beijing Children's Hospital Capital Medical University Beijing China
| | - Zhimei Liu
- Department of Neurology, National Center for Children's Health, Beijing Children's Hospital Capital Medical University Beijing China
| | - Junling Wang
- Department of Neurology, National Center for Children's Health, Beijing Children's Hospital Capital Medical University Beijing China
| | - Danmin Shen
- Department of Neurology, National Center for Children's Health, Beijing Children's Hospital Capital Medical University Beijing China
| | - Hong Jin
- Department of Neurology, National Center for Children's Health, Beijing Children's Hospital Capital Medical University Beijing China
| | - Changhong Ding
- Department of Neurology, National Center for Children's Health, Beijing Children's Hospital Capital Medical University Beijing China
| | - Xiaolu Tang
- Image Center, National Center for Children's Health, Beijing Children's Hospital Capital Medical University Beijing China
| | - Suzhen Sun
- Department of Neurology Children's Hospital of Hebei Province Shijiazhuang China
| | - Hong Han
- Department of Neurology Children's Hospital of Shanxi Province Taiyuan China
| | - Yanli Ma
- Department of Neurology Children's Hospital Affiliated to Zhengzhou University, Henan Children's Hospital Zhengzhou China
| | - Weihua Zhang
- Department of Neurology, National Center for Children's Health, Beijing Children's Hospital Capital Medical University Beijing China
- Department of Neurology Children's Hospital Affiliated to Zhengzhou University, Henan Children's Hospital Zhengzhou China
| | - Ruifeng Jin
- Department of Neurology Qilu Children's Hospital of Shandong University Jinan China
| | - Hua Wang
- Department of Pediatrics Shengjing Hospital of China Medical University Shenyang China
| | - Dan Sun
- Department of Neurology Wuhan Children's Hospital Wuhan China
| | - Jun Lan Lv
- Department of Neurology, National Center for Children's Health, Beijing Children's Hospital Capital Medical University Beijing China
| | - Holger Prokisch
- Institute of Human Genetics, School of Medicine Technical University of Munich Munich Germany
- Institute of Neurogenomics Helmholtz Zentrum München Neuherberg Germany
| | - Fang Fang
- Department of Neurology, National Center for Children's Health, Beijing Children's Hospital Capital Medical University Beijing China
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39
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Leipnitz G, Hatch GM, Mohsen AW, Wanders RJA. Editorial: Mitochondrial Disorders: Biochemical and Molecular Basis of Disease. Front Genet 2021; 12:769770. [PMID: 34868257 PMCID: PMC8640091 DOI: 10.3389/fgene.2021.769770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 10/26/2021] [Indexed: 11/13/2022] Open
Affiliation(s)
- Guilhian Leipnitz
- Post-Graduation Program in Biological Sciences, Biochemistry, Department of Biochemistry, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Grant M Hatch
- Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, MB, Canada
| | - Al-Walid Mohsen
- Division of Genetic and Genomic Medicine, Department of Pediatrics, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | - Ronald J A Wanders
- Laboratory Genetic Metabolic Diseases, Departments Pediatrics, Emma Children Hospital and Clinical Chemistry, Amsterdam University Medical Center, Amsterdam, Netherlands
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40
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Shi Y, Chen G, Sun D, Hu C, Liu Z, Shen D, Wang J, Song T, Zhang W, Li J, Ren X, Han T, Ding C, Wang Y, Fang F. Phenotypes and genotypes of mitochondrial diseases with mtDNA variations in Chinese children: A multi-center study. Mitochondrion 2021; 62:139-150. [PMID: 34800692 DOI: 10.1016/j.mito.2021.11.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Revised: 10/29/2021] [Accepted: 11/12/2021] [Indexed: 11/24/2022]
Abstract
Mitochondrial DNA (mtDNA) associated mitochondrial diseases hold a crucial position but comprehensive and systematic studies are relatively rare. Among the 262 patients of four children's hospitals in China, 96%-point mutations (30 alleles in 11 genes encoding tRNA, rRNA, Complex I and V) and 4%-deletions (seven of ten had not been reported before) were identified as the cause of 14 phenotypes. MILS presented the highest genetic heterogeneity, while the m.3243A > G mutation was the only "hotspot" mutation with a wide range of phenotypes. The degrees of heteroplasmy in the leukocytes of MM were higher than MELAS. The heteroplasmy level of patients was higher than that in mild and carrier group, while we found low-level heteroplasmy pathogenic mutations as well. Some homoplasmic variations (e.g., m.9176 T > C mutation) are having high incomplete penetrance. For a suspected MELAS, m.3243A > G mutation was recommended to detect first; while for a suspected LS, trios-WES and mtDNA genome sequencing by NGS were recommended first in both blood and urine.
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Affiliation(s)
- Yuqing Shi
- Department of Neurology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing 100045, China
| | - Guohong Chen
- Department of Neurology, Zhengzhou University Affiliated Children's Hospital (Zhengzhou Children's Hospital), Zhengzhou 450053, Henan, China
| | - Dan Sun
- Department of Neurology, Wuhan Children's Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430015, China
| | - Chaoping Hu
- Department of Neurology, Children's Hospital of Fudan University, Shanghai 201102, China
| | - Zhimei Liu
- Department of Neurology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing 100045, China
| | - Danmin Shen
- Department of Neurology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing 100045, China
| | - Junling Wang
- Department of Neurology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing 100045, China
| | - Tianyu Song
- Department of Neurology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing 100045, China
| | - Weihua Zhang
- Department of Neurology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing 100045, China
| | - Jiuwei Li
- Department of Neurology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing 100045, China
| | - Xiaotun Ren
- Department of Neurology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing 100045, China
| | - Tongli Han
- Department of Neurology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing 100045, China
| | - Changhong Ding
- Department of Neurology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing 100045, China
| | - Yi Wang
- Department of Neurology, Children's Hospital of Fudan University, Shanghai 201102, China.
| | - Fang Fang
- Department of Neurology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing 100045, China.
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41
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Bellusci M, Paredes-Fuentes AJ, Ruiz-Pesini E, Gómez B, Martín MA, Montoya J, Artuch R. The Genetic Landscape of Mitochondrial Diseases in Spain: A Nationwide Call. Genes (Basel) 2021; 12:genes12101590. [PMID: 34680984 PMCID: PMC8535857 DOI: 10.3390/genes12101590] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 09/30/2021] [Accepted: 10/05/2021] [Indexed: 01/21/2023] Open
Abstract
The frequency of mitochondrial diseases (MD) has been scarcely documented, and only a few studies have reported data in certain specific geographical areas. In this study, we arranged a nationwide call in Spain to obtain a global estimate of the number of cases. A total of 3274 cases from 49 Spanish provinces were reported by 39 centres. Excluding duplicated and unsolved cases, 2761 patients harbouring pathogenic mutations in 140 genes were recruited between 1990 and 2020. A total of 508 patients exhibited mutations in nuclear DNA genes (75% paediatric patients) and 1105 in mitochondrial DNA genes (33% paediatric patients). A further 1148 cases harboured mutations in the MT-RNR1 gene (56% paediatric patients). The number of reported cases secondary to nuclear DNA mutations increased in 2014, owing to the implementation of next-generation sequencing technologies. Between 2014 and 2020, excepting MT-RNR1 cases, the incidence was 6.34 (95% CI: 5.71–6.97) cases per million inhabitants at the paediatric age and 1.36 (95% CI: 1.22–1.50) for adults. In conclusion, this is the first study to report nationwide epidemiological data for MD in Spain. The lack of identification of a remarkable number of mitochondrial genes necessitates the systematic application of high-throughput technologies in the routine diagnosis of MD.
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Affiliation(s)
- Marcello Bellusci
- Reference Centre for Inherited Metabolic Disorders, 12 de Octubre University Hospital, 28041 Madrid, Spain;
- Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain; (E.R.-P.); (B.G.)
| | - Abraham J Paredes-Fuentes
- Clinical Biochemistry Department, Institut de Recerca Sant Joan de Déu, Hospital Sant Joan de Déu, Esplugues de Llobregat, 08950 Barcelona, Spain;
| | - Eduardo Ruiz-Pesini
- Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain; (E.R.-P.); (B.G.)
- Department of Biochemistry and Molecular Biology, Institute for Health Research of Aragón (IISAragón), University of Zaragoza, 50009 Zaragoza, Spain
| | - Beatriz Gómez
- Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain; (E.R.-P.); (B.G.)
| | | | - Miguel A Martín
- Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain; (E.R.-P.); (B.G.)
- Mitochondrial & Neuromuscular Disorders Laboratory, Instituto de Investigación Sanitaria 12 de Octubre (imas12), 28041 Madrid, Spain
- Correspondence: (M.A.M.); (J.M.); (R.A.)
| | - Julio Montoya
- Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain; (E.R.-P.); (B.G.)
- Department of Biochemistry and Molecular Biology, Institute for Health Research of Aragón (IISAragón), University of Zaragoza, 50009 Zaragoza, Spain
- Correspondence: (M.A.M.); (J.M.); (R.A.)
| | - Rafael Artuch
- Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain; (E.R.-P.); (B.G.)
- Clinical Biochemistry Department, Institut de Recerca Sant Joan de Déu, Hospital Sant Joan de Déu, Esplugues de Llobregat, 08950 Barcelona, Spain;
- Correspondence: (M.A.M.); (J.M.); (R.A.)
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42
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Domínguez-González C, Madruga-Garrido M, Hirano M, Martí I, Martín MA, Munell F, Nascimento A, Olivé M, Quan J, Sardina MD, Martí R, Paradas C. Collaborative model for diagnosis and treatment of very rare diseases: experience in Spain with thymidine kinase 2 deficiency. Orphanet J Rare Dis 2021; 16:407. [PMID: 34600563 PMCID: PMC8487573 DOI: 10.1186/s13023-021-02030-w] [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: 06/17/2021] [Accepted: 09/18/2021] [Indexed: 11/22/2022] Open
Abstract
Background Mitochondrial diseases are difficult to diagnose and treat. Recent advances in genetic diagnostics and more effective treatment options can improve patient diagnosis and prognosis, but patients with mitochondrial disease typically experience delays in diagnosis and treatment. Here, we describe a unique collaborative practice model among physicians and scientists in Spain focused on identifying TK2 deficiency (TK2d), an ultra-rare mitochondrial DNA depletion and deletions syndrome.
Main Body This collaboration spans research and clinical care, including laboratory scientists, adult and pediatric neuromuscular clinicians, geneticists, and pathologists, and has resulted in diagnosis and consolidation of care for patients with TK2d. The incidence of TK2d is not known; however, the first clinical cases of TK2d were reported in 2001, and only ~ 107 unique cases had been reported as of 2018. This unique collaboration in Spain has led to the diagnosis of more than 30 patients with genetically confirmed TK2d across different regions of the country. Research affiliate centers have led investigative treatment with nucleosides based on understanding of TK2d clinical manifestations and disease mechanisms, which resulted in successful treatment of a TK2d mouse model with nucleotide therapy in 2010. Only 1 year later, this collaboration enabled rapid adoption of treatment with pyrimidine nucleotides (and later, nucleosides) under compassionate use. Success in TK2d diagnosis and treatment in Spain is attributable to two important factors: Spain’s fully public national healthcare system, and the designation in 2015 of major National Reference Centers for Neuromuscular Disorders (CSURs). CSUR networking and dissemination facilitated development of a collaborative care network for TK2d disease, wherein participants share information and protocols to request approval from the Ministry of Health to initiate nucleoside therapy. Data have recently been collected in a retrospective study conducted under a Good Clinical Practice–compliant protocol to support development of a new therapeutic approach for TK2d, a progressive disease with no approved therapies. Conclusions The Spanish experience in diagnosis and treatment of TK2d is a model for the diagnosis and development of new treatments for very rare diseases within an existing healthcare system.
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Affiliation(s)
- Cristina Domínguez-González
- Neuromuscular Disorders Unit, Neurology Department, Hospital 12 de Octubre, Madrid, Spain.,Instituto de Investigación imas12, Hospital 12 de Octubre, Madrid, Spain.,Center for Biomedical Network Research On Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | | | - Michio Hirano
- Neurology Department, H. Houston Merritt Center, Columbia University Irving Medical Center, New York, NY, USA
| | - Itxaso Martí
- Pediatric Department, Donostia University Hospital, Biodonostia Health Research Institute, University of the Basque Country, San Sebastián, Spain
| | - Miguel A Martín
- Center for Biomedical Network Research On Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain.,Mitochondrial Diseases Laboratory, Department of Biochemistry, Research Institute Hospital 12 de Octubre (imas12), Madrid, Spain
| | - Francina Munell
- Pediatric Department, Vall d'Hebron Hospital, Barcelona, Spain
| | - Andrés Nascimento
- Center for Biomedical Network Research On Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain.,Pediatric Department, Vall d'Hebron Hospital, Barcelona, Spain.,Neuromuscular Unit, Neurology Department, Sant Joan de Déu Research Institute, Sant Joan de Déu Hospital, Barcelona, Spain
| | - Montse Olivé
- Neuromuscular Disorders Unit, Department of Neurology, Hospital de la Santa Creu i Sant Pau/Center for Biomedical Network Research On Rare Diseases (CIBERER), Barcelona, Spain
| | | | - M Dolores Sardina
- Pediatric Neurology Department, Badajoz Hospital Complex, Badajoz, Spain
| | - Ramon Martí
- Center for Biomedical Network Research On Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain.,Research Group On Neuromuscular and Mitochondrial Diseases, Vall d'Hebron Research Institute, Autonomous University of Barcelona, Barcelona, Spain
| | - Carmen Paradas
- Neurology Department, Neuromuscular Disorders Unit, Instituto de Biomedicina de Sevilla, Hospital U. Virgen del Rocío, CSIC, Universidad de Sevilla, Avd. Manuel Siurot s/n, 41013, Sevilla, Spain. .,Center for Biomedical Network Research On Neurodegenerative Disorders (CIBERNED), Instituto de Salud Carlos III, Madrid, Spain.
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43
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Ratnaike TE, Greene D, Wei W, Sanchis-Juan A, Schon KR, van den Ameele J, Raymond L, Horvath R, Turro E, Chinnery PF. MitoPhen database: a human phenotype ontology-based approach to identify mitochondrial DNA diseases. Nucleic Acids Res 2021; 49:9686-9695. [PMID: 34428295 PMCID: PMC8464050 DOI: 10.1093/nar/gkab726] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 08/03/2021] [Accepted: 08/18/2021] [Indexed: 12/23/2022] Open
Abstract
Diagnosing mitochondrial disorders remains challenging. This is partly because the clinical phenotypes of patients overlap with those of other sporadic and inherited disorders. Although the widespread availability of genetic testing has increased the rate of diagnosis, the combination of phenotypic and genetic heterogeneity still makes it difficult to reach a timely molecular diagnosis with confidence. An objective, systematic method for describing the phenotypic spectra for each variant provides a potential solution to this problem. We curated the clinical phenotypes of 6688 published individuals with 89 pathogenic mitochondrial DNA (mtDNA) mutations, collating 26 348 human phenotype ontology (HPO) terms to establish the MitoPhen database. This enabled a hypothesis-free definition of mtDNA clinical syndromes, an overview of heteroplasmy-phenotype relationships, the identification of under-recognized phenotypes, and provides a publicly available reference dataset for objective clinical comparison with new patients using the HPO. Studying 77 patients with independently confirmed positive mtDNA diagnoses and 1083 confirmed rare disease cases with a non-mitochondrial nuclear genetic diagnosis, we show that HPO-based phenotype similarity scores can distinguish these two classes of rare disease patients with a false discovery rate <10% at a sensitivity of 80%. Enriching the MitoPhen database with more patients will improve predictions for increasingly rare variants.
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Affiliation(s)
- Thiloka E Ratnaike
- Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK.,Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK.,Department of Paediatrics, University of Cambridge, Cambridge Biomedical Campus, Cambridge CB2 0QQ, UK
| | - Daniel Greene
- Department of Haematology, University of Cambridge, NHS Blood and Transplant, Cambridge Biomedical Campus, Cambridge CB2 0PT, UK.,Medical Research Council Biostatistics Unit, Cambridge Biomedical Campus, Cambridge CB2 0SR, UK
| | - Wei Wei
- Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK.,Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK
| | - Alba Sanchis-Juan
- Department of Haematology, University of Cambridge, NHS Blood and Transplant, Cambridge Biomedical Campus, Cambridge CB2 0PT, UK
| | - Katherine R Schon
- Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK.,Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK.,Department of Medical Genetics, School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK
| | - Jelle van den Ameele
- Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK.,Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK
| | - Lucy Raymond
- Department of Medical Genetics, School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK
| | - Rita Horvath
- Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK.,Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK
| | - Ernest Turro
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Patrick F Chinnery
- Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK.,Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK
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44
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Luo Q, Wen X, Zhou J, Chen Y, Lv Z, Shen X, Liu J. A novel compound heterozygous mutation of the MTO1 gene associated with complex oxidative phosphorylation deficiency type 10. Clin Chim Acta 2021; 523:172-177. [PMID: 34547275 DOI: 10.1016/j.cca.2021.09.014] [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: 04/14/2021] [Revised: 09/08/2021] [Accepted: 09/15/2021] [Indexed: 10/20/2022]
Abstract
BACKGROUND The mitochondrial tRNA translation optimization 1 (MTO1) gene, which is closely related to defective mitochondrial oxidative phosphorylation, is an evolutionarily conserved protein expressed in high energy-demanding tissues and is associated with complex oxidative phosphorylation deficiency type 10 (COXPD10) in humans. Related cases and studies are still scarce and have not been reported in the Chinese region. MATERIALS AND METHODS Detailed clinical assessment was applied to the patient. Based on next-generation sequencing technology, we performed whole-exome sequencing of the patient and the parents. Sanger sequencing was used for validation. Bioinformatics software and protein simulations were used to predict the pathogenicity of the variants. RESULTS The patient was diagnosed with a possible association with mitochondrial disease according to the clinical manifestations and physical examination. A novel frameshift mutation c.344delA (p. Asn115Thrfs*11) and a novel point mutation c.1055C > T (p. Thr352Met) in the MTO1 gene were identified. They were found to cause abnormal changes in amino acids and the protein by biochemical tools, indicating it may be pathogenic. CONCLUSION We present two novel and possibly pathogenic variants in the MTO1 gene in a Chinese Han family.
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Affiliation(s)
- Qing Luo
- Department of Laboratory Medicine, Affiliated Hospital of Southwest Medical University, 25 Taiping Street, Luzhou, Sichuan 646000, China
| | - Xia Wen
- Department of Laboratory Medicine, Affiliated Hospital of Southwest Medical University, 25 Taiping Street, Luzhou, Sichuan 646000, China
| | - Jiahong Zhou
- Department of Laboratory Medicine, Affiliated Hospital of Southwest Medical University, 25 Taiping Street, Luzhou, Sichuan 646000, China
| | - Yang Chen
- Department of Laboratory Medicine, Affiliated Hospital of Southwest Medical University, 25 Taiping Street, Luzhou, Sichuan 646000, China
| | - Zhiyu Lv
- Department of Neurology, Affiliated Hospital of Southwest Medical University, 25 Taiping Street, Luzhou, Sichuan 646000, China
| | - Xing Shen
- Pediatric Intensive Care Unit, Affiliated Hospital of Southwest Medical University, 25 Taiping Street, Luzhou, Sichuan 646000, China
| | - Jinbo Liu
- Department of Laboratory Medicine, Affiliated Hospital of Southwest Medical University, 25 Taiping Street, Luzhou, Sichuan 646000, China.
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45
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Acin-Perez R, Benincá C, Shabane B, Shirihai OS, Stiles L. Utilization of Human Samples for Assessment of Mitochondrial Bioenergetics: Gold Standards, Limitations, and Future Perspectives. Life (Basel) 2021; 11:949. [PMID: 34575097 PMCID: PMC8467772 DOI: 10.3390/life11090949] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 08/12/2021] [Accepted: 08/23/2021] [Indexed: 12/15/2022] Open
Abstract
Mitochondrial bioenergetic function is a central component of cellular metabolism in health and disease. Mitochondrial oxidative phosphorylation is critical for maintaining energetic homeostasis, and impairment of mitochondrial function underlies the development and progression of metabolic diseases and aging. However, measurement of mitochondrial bioenergetic function can be challenging in human samples due to limitations in the size of the collected sample. Furthermore, the collection of samples from human cohorts is often spread over multiple days and locations, which makes immediate sample processing and bioenergetics analysis challenging. Therefore, sample selection and choice of tests should be carefully considered. Basic research, clinical trials, and mitochondrial disease diagnosis rely primarily on skeletal muscle samples. However, obtaining skeletal muscle biopsies requires an appropriate clinical setting and specialized personnel, making skeletal muscle a less suitable tissue for certain research studies. Circulating white blood cells and platelets offer a promising primary tissue alternative to biopsies for the study of mitochondrial bioenergetics. Recent advances in frozen respirometry protocols combined with the utilization of minimally invasive and non-invasive samples may provide promise for future mitochondrial research studies in humans. Here we review the human samples commonly used for the measurement of mitochondrial bioenergetics with a focus on the advantages and limitations of each sample.
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Affiliation(s)
- Rebeca Acin-Perez
- Department of Medicine, Endocrinology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA; (C.B.); (B.S.); (O.S.S.)
- Metabolism Theme, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Cristiane Benincá
- Department of Medicine, Endocrinology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA; (C.B.); (B.S.); (O.S.S.)
- Metabolism Theme, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Byourak Shabane
- Department of Medicine, Endocrinology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA; (C.B.); (B.S.); (O.S.S.)
- Metabolism Theme, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Orian S. Shirihai
- Department of Medicine, Endocrinology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA; (C.B.); (B.S.); (O.S.S.)
- Metabolism Theme, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, CA 90095, USA
- Molecular Biology Institute, University of California, Los Angeles, CA 90095, USA
| | - Linsey Stiles
- Department of Medicine, Endocrinology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA; (C.B.); (B.S.); (O.S.S.)
- Metabolism Theme, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, CA 90095, USA
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46
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Gusic M, Prokisch H. Genetic basis of mitochondrial diseases. FEBS Lett 2021; 595:1132-1158. [PMID: 33655490 DOI: 10.1002/1873-3468.14068] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 02/17/2021] [Accepted: 02/18/2021] [Indexed: 12/13/2022]
Abstract
Mitochondrial disorders are monogenic disorders characterized by a defect in oxidative phosphorylation and caused by pathogenic variants in one of over 340 different genes. The implementation of whole-exome sequencing has led to a revolution in their diagnosis, duplicated the number of associated disease genes, and significantly increased the diagnosed fraction. However, the genetic etiology of a substantial fraction of patients exhibiting mitochondrial disorders remains unknown, highlighting limitations in variant detection and interpretation, which calls for improved computational and DNA sequencing methods, as well as the addition of OMICS tools. More intriguingly, this also suggests that some pathogenic variants lie outside of the protein-coding genes and that the mechanisms beyond the Mendelian inheritance and the mtDNA are of relevance. This review covers the current status of the genetic basis of mitochondrial diseases, discusses current challenges and perspectives, and explores the contribution of factors beyond the protein-coding regions and monogenic inheritance in the expansion of the genetic spectrum of disease.
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Affiliation(s)
- Mirjana Gusic
- Institute of Neurogenomics, Helmholtz Zentrum München, Neuherberg, Germany.,Institute of Human Genetics, Technical University of Munich, Germany.,DZHK (German Centre for Cardiovascular Research), Partner Site Munich Heart Alliance, Germany
| | - Holger Prokisch
- Institute of Neurogenomics, Helmholtz Zentrum München, Neuherberg, Germany.,Institute of Human Genetics, Technical University of Munich, Germany
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