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Conte TC, Duran-Bishop G, Orfi Z, Mokhtari I, Deprez A, Côté I, Molina T, Kim TY, Tellier L, Roussel MP, Maggiorani D, Benabdallah B, Leclerc S, Feulner L, Pellerito O, Mathieu J, Andelfinger G, Gagnon C, Beauséjour C, McGraw S, Duchesne E, Dumont NA. Clearance of defective muscle stem cells by senolytics restores myogenesis in myotonic dystrophy type 1. Nat Commun 2023; 14:4033. [PMID: 37468473 PMCID: PMC10356779 DOI: 10.1038/s41467-023-39663-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 06/22/2023] [Indexed: 07/21/2023] Open
Abstract
Muscle stem cells, the engine of muscle repair, are affected in myotonic dystrophy type 1 (DM1); however, the underlying molecular mechanism and the impact on the disease severity are still elusive. Here, we show using patients' samples that muscle stem cells/myoblasts exhibit signs of cellular senescence in vitro and in situ. Single cell RNAseq uncovers a subset of senescent myoblasts expressing high levels of genes related to the senescence-associated secretory phenotype (SASP). We show that the levels of interleukin-6, a prominent SASP cytokine, in the serum of DM1 patients correlate with muscle weakness and functional capacity limitations. Drug screening revealed that the senolytic BCL-XL inhibitor (A1155463) can specifically remove senescent DM1 myoblasts by inducing their apoptosis. Clearance of senescent cells reduced the expression of SASP, which rescued the proliferation and differentiation capacity of DM1 myoblasts in vitro and enhanced their engraftment following transplantation in vivo. Altogether, this study identifies the pathogenic mechanism associated with muscle stem cell defects in DM1 and opens a therapeutic avenue that targets these defective cells to restore myogenesis.
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Affiliation(s)
- Talita C Conte
- CHU Sainte-Justine Research Center, Montreal, QC, Canada
- Department of pharmacology and physiology, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Gilberto Duran-Bishop
- CHU Sainte-Justine Research Center, Montreal, QC, Canada
- Department of obstetrics and gynecology, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Zakaria Orfi
- CHU Sainte-Justine Research Center, Montreal, QC, Canada
- Department of pharmacology and physiology, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Inès Mokhtari
- CHU Sainte-Justine Research Center, Montreal, QC, Canada
- Department of Health Sciences, Université du Québec à Chicoutimi, Saguenay, QC, Canada
- Neuromuscular diseases interdisciplinary research group (GRIMN), Saguenay-Lac-St-Jean Integrated University Health and Social Services Center, Saguenay, QC, Canada
| | - Alyson Deprez
- CHU Sainte-Justine Research Center, Montreal, QC, Canada
- Department of pharmacology and physiology, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Isabelle Côté
- Neuromuscular diseases interdisciplinary research group (GRIMN), Saguenay-Lac-St-Jean Integrated University Health and Social Services Center, Saguenay, QC, Canada
| | - Thomas Molina
- CHU Sainte-Justine Research Center, Montreal, QC, Canada
- Department of pharmacology and physiology, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Tae-Yeon Kim
- CHU Sainte-Justine Research Center, Montreal, QC, Canada
- Department of microbiology, infectiology and immunology, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Lydia Tellier
- CHU Sainte-Justine Research Center, Montreal, QC, Canada
- School of rehabilitation, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Marie-Pier Roussel
- Neuromuscular diseases interdisciplinary research group (GRIMN), Saguenay-Lac-St-Jean Integrated University Health and Social Services Center, Saguenay, QC, Canada
- Department of Fundamental Sciences, Université du Québec à Chicoutimi, Saguenay, QC, Canada
| | - Damien Maggiorani
- CHU Sainte-Justine Research Center, Montreal, QC, Canada
- Department of pharmacology and physiology, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | | | | | - Lara Feulner
- CHU Sainte-Justine Research Center, Montreal, QC, Canada
| | | | - Jean Mathieu
- Neuromuscular diseases interdisciplinary research group (GRIMN), Saguenay-Lac-St-Jean Integrated University Health and Social Services Center, Saguenay, QC, Canada
- CHU Sherbrooke Research Center, and Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Gregor Andelfinger
- CHU Sainte-Justine Research Center, Montreal, QC, Canada
- Department of Pediatrics, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Cynthia Gagnon
- Neuromuscular diseases interdisciplinary research group (GRIMN), Saguenay-Lac-St-Jean Integrated University Health and Social Services Center, Saguenay, QC, Canada
- CHU Sherbrooke Research Center, and Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Christian Beauséjour
- CHU Sainte-Justine Research Center, Montreal, QC, Canada
- Department of pharmacology and physiology, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Serge McGraw
- CHU Sainte-Justine Research Center, Montreal, QC, Canada
- Department of obstetrics and gynecology, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Elise Duchesne
- Department of Health Sciences, Université du Québec à Chicoutimi, Saguenay, QC, Canada.
- Neuromuscular diseases interdisciplinary research group (GRIMN), Saguenay-Lac-St-Jean Integrated University Health and Social Services Center, Saguenay, QC, Canada.
| | - Nicolas A Dumont
- CHU Sainte-Justine Research Center, Montreal, QC, Canada.
- School of rehabilitation, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada.
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Koc ZC, Sollars VE, Bou Zgheib N, Rankin GO, Koc EC. Evaluation of mitochondrial biogenesis and ROS generation in high-grade serous ovarian cancer. Front Oncol 2023; 13:1129352. [PMID: 36937395 PMCID: PMC10014927 DOI: 10.3389/fonc.2023.1129352] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 02/08/2023] [Indexed: 03/05/2023] Open
Abstract
Introduction Ovarian cancer is one of the leading causes of death for women with cancer worldwide. Energy requirements for tumor growth in epithelial high-grade serous ovarian cancer (HGSOC) are fulfilled by a combination of aerobic glycolysis and oxidative phosphorylation (OXPHOS). Although reduced OXPHOS activity has emerged as one of the significant contributors to tumor aggressiveness and chemoresistance, up-regulation of mitochondrial antioxidant capacity is required for matrix detachment and colonization into the peritoneal cavity to form malignant ascites in HGSOC patients. However, limited information is available about the mitochondrial biogenesis regulating OXPHOS capacity and generation of mitochondrial reactive oxygen species (mtROS) in HGSOC. Methods To evaluate the modulation of OXPHOS in HGSOC tumor samples and ovarian cancer cell lines, we performed proteomic analyses of proteins involved in mitochondrial energy metabolism and biogenesis and formation of mtROS by immunoblotting and flow cytometry, respectively. Results and discussion We determined that the increased steady-state expression levels of mitochondrial- and nuclear-encoded OXPHOS subunits were associated with increased mitochondrial biogenesis in HGSOC tumors and ovarian cancer cell lines. The more prominent increase in MT-COII expression was in agreement with significant increase in mitochondrial translation factors, TUFM and DARS2. On the other hand, the ovarian cancer cell lines with reduced OXPHOS subunit expression and mitochondrial translation generated the highest levels of mtROS and significantly reduced SOD2 expression. Evaluation of mitochondrial biogenesis suggested that therapies directed against mitochondrial targets, such as those involved in transcription and translation machineries, should be considered in addition to the conventional chemotherapies in HGSOC treatment.
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Affiliation(s)
- Zeynep C. Koc
- Department of Obstetrics, Gynecology and Reproductive Sciences, Temple University, Philadelphia, PA, United States
| | - Vincent E. Sollars
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV, United States
| | - Nadim Bou Zgheib
- Edwards Comprehensive Cancer Center, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV, United States
| | - Gary O. Rankin
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV, United States
| | - Emine C. Koc
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV, United States
- *Correspondence: Emine C. Koc,
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A Novel PUS1 Mutation in 2 Siblings with MLASA Syndrome: A Review of the Literature. J Pediatr Hematol Oncol 2021; 43:e592-e595. [PMID: 32287105 DOI: 10.1097/mph.0000000000001806] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Accepted: 03/20/2020] [Indexed: 01/28/2023]
Abstract
ABSTRACT Myopathy, lactic acidosis, and sideroblastic anemia (MLASA) is a rare mitochondrial disorder characterized by MLASA. Variable features of this condition include failure to thrive, and developmental delay or intellectual disability. Additional symptoms consist of cognitive impairment, skeletal and dental abnormalities, delayed motor milestones, cardiomyopathy, dysphagia, and respiratory insufficiency. MLASA has previously been associated with mutations in pseudouridylate synthase 1 (PUS1) and YARS2. PUS1 encodes the nuclear PUS1 enzyme, which is located in both the nucleus and the mitochondria. PUS1 converts uridine into pseudouridine in several cytosolic and mitochondrial transfer RNA positions and increases the efficiency of protein synthesis in both compartments.In the present report, we report on 2 Turkish sisters 4 and 11 of years with an MLASA plus phenotype. Both patients have sideroblastic anemia, lactic acidosis, failure to thrive, developmental delay, and chronic diarrhea; in addition, the older sister has strabismus and skeletal anomalies. The sequencing of the PUS1 gene revealed a novel homozygous p.Glu311* mutation. The phenotype of the older sibling is also unique because of the strabismus and skeletal anomalies, when compared with her sister and other previously reported patients with MLASA. The structural differences in the nuclear versus mitochondrial isoforms of PUS1 and modifier genes may be implicated in the variability of the clinical presentations in MLASA. CONCLUSION This report adds to the growing number of mutations causing complex clinical manifestations of MLASA including lactic acidosis, sideroblastic anemia, chronic diarrhea, and myopathy.
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Ruparelia AA, McKaige EA, Williams C, Schulze KE, Fuchs M, Oorschot V, Lacene E, Meregalli M, Lee C, Serrano RJ, Baxter EC, Monro K, Torrente Y, Ramm G, Stojkovic T, Lavoie JN, Bryson-Richardson RJ. Metformin rescues muscle function in BAG3 myofibrillar myopathy models. Autophagy 2020; 17:2494-2510. [DOI: 10.1080/15548627.2020.1833500] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Affiliation(s)
| | - Emily A. McKaige
- School of Biological Sciences, Monash University, Melbourne, Australia
| | - Caitlin Williams
- School of Biological Sciences, Monash University, Melbourne, Australia
| | | | - Margit Fuchs
- Centre de Recherche Sur le Cancer de l’Université Laval, Ville de Québec, Canada
- Oncologie, Centre de Recherche du Centre Hospitalier Universitaire (CHU) de Québec-Université Laval, Ville de Québec, Canada
| | - Viola Oorschot
- Monash Ramaciotti Centre for Structural Cryo-Electron Microscopy, Monash University, Melbourne, Australia
| | - Emmanuelle Lacene
- Institut de Myologie, Laboratoire de Pathologie Risler, APHP, Centre de Référence de Pathologie Neuromusculaire Nord/Est/Ile-de-France, Paris, France
| | - Mirella Meregalli
- Stem Cell Laboratory, Department of Pathophysiology and Transplantation, Università Degli Studi di Milano, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico di Milano, Centro Dino Ferrari, Milan, Italy
| | - Clara Lee
- School of Biological Sciences, Monash University, Melbourne, Australia
| | - Rita J. Serrano
- School of Biological Sciences, Monash University, Melbourne, Australia
| | - Emily C. Baxter
- School of Biological Sciences, Monash University, Melbourne, Australia
| | - Keyne Monro
- School of Biological Sciences, Monash University, Melbourne, Australia
| | - Yvan Torrente
- Stem Cell Laboratory, Department of Pathophysiology and Transplantation, Università Degli Studi di Milano, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico di Milano, Centro Dino Ferrari, Milan, Italy
| | - Georg Ramm
- Monash Ramaciotti Centre for Structural Cryo-Electron Microscopy, Monash University, Melbourne, Australia
- Biochemistry and Molecular Biology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Australia
| | - Tanya Stojkovic
- Institut de Myologie, Centre de Référence des Maladies Neuromusculaires, Hôpital Pitié-Salpétrière, Assistance-Publique Hôpitaux de Paris, Sorbonne Université, Paris, France
| | - Josée N. Lavoie
- Centre de Recherche Sur le Cancer de l’Université Laval, Ville de Québec, Canada
- Oncologie, Centre de Recherche du Centre Hospitalier Universitaire (CHU) de Québec-Université Laval, Ville de Québec, Canada
- Département de Biologie Moléculaire, Biochimie Médicale et Pathologie, Université Laval, Ville de Québec, Canada
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Konovalova S, Hilander T, Loayza-Puch F, Rooijers K, Agami R, Tyynismaa H. Exposure to arginine analog canavanine induces aberrant mitochondrial translation products, mitoribosome stalling, and instability of the mitochondrial proteome. Int J Biochem Cell Biol 2015; 65:268-74. [DOI: 10.1016/j.biocel.2015.06.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Revised: 06/01/2015] [Accepted: 06/22/2015] [Indexed: 10/23/2022]
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Histological and immunohistochemical study on the effect of aflatoxin B1 on the left ventricular muscle of adult male rabbit with reference to the protective role of melatonin. ACTA ACUST UNITED AC 2014. [DOI: 10.1097/01.ehx.0000455682.80650.e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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7
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Burrage LC, Tang S, Wang J, Donti TR, Walkiewicz M, Luchak JM, Chen LC, Schmitt ES, Niu Z, Erana R, Hunter JV, Graham BH, Wong LJ, Scaglia F. Mitochondrial myopathy, lactic acidosis, and sideroblastic anemia (MLASA) plus associated with a novel de novo mutation (m.8969G>A) in the mitochondrial encoded ATP6 gene. Mol Genet Metab 2014; 113:207-12. [PMID: 25037980 PMCID: PMC4253070 DOI: 10.1016/j.ymgme.2014.06.004] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2014] [Revised: 06/24/2014] [Accepted: 06/24/2014] [Indexed: 11/18/2022]
Abstract
Mitochondrial myopathy, lactic acidosis and sideroblastic anemia (MLASA) is a rare mitochondrial disorder that has previously been associated with mutations in PUS1 and YARS2. In the present report, we describe a 6-year old male with an MLASA plus phenotype. This patient had features of MLASA in the setting of developmental delay, sensorineural hearing loss, epilepsy, agenesis of the corpus callosum, failure to thrive, and stroke-like episodes. Sequencing of the mitochondrial genome identified a novel de novo, heteroplasmic mutation in the mitochondrial DNA (mtDNA) encoded ATP6 gene (m.8969G>A, p.S148N). Whole exome sequencing did not identify mutations or variants in PUS1 or YARS2 or any known nuclear genes that could affect mitochondrial function and explain this phenotype. Studies of fibroblasts derived from the patient revealed a decrease in oligomycin-sensitive respiration, a finding which is consistent with a complex V defect. Thus, this mutation in MT-ATP6 may represent the first mtDNA point mutation associated with the MLASA phenotype.
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Affiliation(s)
- Lindsay C Burrage
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
| | - Sha Tang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
| | - Jing Wang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
| | - Taraka R Donti
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
| | - Magdalena Walkiewicz
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
| | - J Michael Luchak
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
| | - Li-Chieh Chen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
| | - Eric S Schmitt
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
| | - Zhiyv Niu
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
| | - Rodrigo Erana
- Department of Pediatrics, Division of Hematology and Oncology, Baylor College of Medicine, Houston, TX, USA.
| | - Jill V Hunter
- Department of Radiology, Baylor College of Medicine, Houston, TX, USA.
| | - Brett H Graham
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
| | - Lee-Jun Wong
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
| | - Fernando Scaglia
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
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Shahni R, Wedatilake Y, Cleary MA, Lindley KJ, Sibson KR, Rahman S. A distinct mitochondrial myopathy, lactic acidosis and sideroblastic anemia (MLASA) phenotype associates with YARS2 mutations. Am J Med Genet A 2013; 161A:2334-8. [PMID: 23918765 PMCID: PMC3884767 DOI: 10.1002/ajmg.a.36065] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Accepted: 05/02/2013] [Indexed: 01/19/2023]
Abstract
Nuclear-encoded disorders of mitochondrial translation are clinically and genetically heterogeneous. Genetic causes include defects of mitochondrial aminoacyl-tRNA synthetases, and factors required for initiation, elongation and termination of protein synthesis as well as ribosome recycling. We report on a new case of myopathy, lactic acidosis and sideroblastic anemia (MLASA) syndrome caused by defective mitochondrial tyrosyl aminoacylation. The patient presented at 1 year with anemia initially attributed to iron deficiency. Bone marrow aspirate at 5 years revealed ringed sideroblasts but transfusion dependency did not occur until 11 years. Other clinical features included lactic acidosis, poor weight gain, hypertrophic cardiomyopathy and severe myopathy leading to respiratory failure necessitating ventilatory support. Long-range PCR excluded mitochondrial DNA rearrangements. Clinical diagnosis of MLASA prompted direct sequence analysis of the YARS2 gene encoding the mitochondrial tyrosyl-tRNA synthetase, which revealed homozygosity for a known pathogenic mutation, c.156C>G;p.F52L. Comparison with four previously reported cases demonstrated remarkable clinical homogeneity. First line investigation of MLASA should include direct sequence analysis of YARS2 and PUS1 (encoding a tRNA modification factor) rather than muscle biopsy. Early genetic diagnosis is essential for counseling and to facilitate appropriate supportive therapy. Reasons for segregation of specific clinical phenotypes with particular mitochondrial aminoacyl tRNA-synthetase defects remain unknown. © 2013 Wiley Periodicals, Inc.
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Affiliation(s)
- Rojeen Shahni
- Mitochondrial Research Group, Clinical and Molecular Genetics Unit, UCL Institute of Child HealthLondon, UK
| | - Yehani Wedatilake
- Mitochondrial Research Group, Clinical and Molecular Genetics Unit, UCL Institute of Child HealthLondon, UK
| | | | - Keith J Lindley
- Gastroenterology Unit, Great Ormond Street HospitalLondon, UK
| | - Keith R Sibson
- Haematology Unit, Great Ormond Street HospitalLondon, UK
| | - Shamima Rahman
- Mitochondrial Research Group, Clinical and Molecular Genetics Unit, UCL Institute of Child HealthLondon, UK
- Metabolic Unit, Great Ormond Street HospitalLondon, UK
- *Correspondence to:, Dr. Shamima Rahman, Mitochondrial Research Group, Clinical and Molecular Genetics Unit, UCL Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK., E-mail:
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Richter U, Lahtinen T, Marttinen P, Myöhänen M, Greco D, Cannino G, Jacobs H, Lietzén N, Nyman T, Battersby B. A Mitochondrial Ribosomal and RNA Decay Pathway Blocks Cell Proliferation. Curr Biol 2013; 23:535-41. [DOI: 10.1016/j.cub.2013.02.019] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Revised: 01/21/2013] [Accepted: 02/08/2013] [Indexed: 12/28/2022]
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10
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Schwenzer H, Zoll J, Florentz C, Sissler M. Pathogenic implications of human mitochondrial aminoacyl-tRNA synthetases. Top Curr Chem (Cham) 2013; 344:247-92. [PMID: 23824528 DOI: 10.1007/128_2013_457] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Mitochondria are considered as the powerhouse of eukaryotic cells. They host several central metabolic processes fueling the oxidative phosphorylation pathway (OXPHOS) that produces ATP from its precursors ADP and inorganic phosphate Pi (PPi). The respiratory chain complexes responsible for the OXPHOS pathway are formed from complementary sets of protein subunits encoded by the nuclear genome and the mitochondrial genome, respectively. The expression of the mitochondrial genome requires a specific and fully active translation machinery from which aminoacyl-tRNA synthetases (aaRSs) are key actors. Whilst the macromolecules involved in mammalian mitochondrial translation have been under investigation for many years, there has been an explosion of interest in human mitochondrial aaRSs (mt-aaRSs) since the discovery of a large (and growing) number of mutations in these genes that are linked to a variety of neurodegenerative disorders. Herein we will review the present knowledge on mt-aaRSs in terms of their biogenesis, their connection to mitochondrial respiration, i.e., the respiratory chain (RC) complexes, and to the mitochondrial translation machinery. The pathology-related mutations detected so far are described, with special attention given to their impact on mt-aaRSs biogenesis, functioning, and/or subsequent activities. The collected data to date shed light on the diverse routes that are linking primary molecular possible impact of a mutation to its phenotypic expression. It is envisioned that a variety of mechanisms, inside and outside the translation machinery, would play a role on the heterogeneous manifestations of mitochondrial disorders.
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Affiliation(s)
- Hagen Schwenzer
- Architecture et Réactivité de l'ARN, CNRS, Université de Strasbourg, IBMC, 15 rue René Descartes, 67084, Strasbourg Cedex, France,
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11
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Sasarman F, Nishimura T, Thiffault I, Shoubridge EA. A novel mutation in YARS2 causes myopathy with lactic acidosis and sideroblastic anemia. Hum Mutat 2012; 33:1201-6. [PMID: 22504945 DOI: 10.1002/humu.22098] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2012] [Accepted: 03/30/2012] [Indexed: 11/08/2022]
Abstract
Mutations in the mitochondrial aminoacyl-tRNA synthetases (ARSs) are associated with a strikingly broad range of clinical phenotypes, the molecular basis for which remains obscure. Here, we report a novel missense mutation (c.137G>A, p.Gly46Asp) in the catalytic domain of YARS2, which codes for the mitochondrial tyrosyl-tRNA synthetase, in a subject with myopathy, lactic acidosis, and sideroblastic anemia (MLASA). YARS2 was undetectable by immunoblot analysis in subject myoblasts, resulting in a generalized mitochondrial translation defect. Retroviral expression of a wild-type YARS2 complementary DNA completely rescued the translation defect. We previously demonstrated that the respiratory chain defect in this subject was only present in fully differentiated muscle, and we show here that this likely reflects an increased requirement for YARS2 as muscle cells differentiate. An additional, heterozygous mutation was detected in TRMU/MTU1, a gene encoding the mitochondrial 2-thiouridylase. Although subject myoblasts and myotubes contained half the normal levels of TRMU, thiolation of mitochondrial tRNAs was normal. YARS2 eluted as part of high-molecular-weight complexes of ∼250 kDa and 1 MDa by gel filtration. This study confirms mutations in YARS2 as a cause of MLASA and shows that, like some of the cytoplasmic ARSs, mitochondrial ARSs occur in high-molecular-weight complexes.
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Affiliation(s)
- Florin Sasarman
- Montreal Neurological Institute, McGill University, Montreal, Canada
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12
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Adaptation of respiratory chain biogenesis to cytochrome c oxidase deficiency caused by SURF1 gene mutations. Biochim Biophys Acta Mol Basis Dis 2012; 1822:1114-24. [PMID: 22465034 DOI: 10.1016/j.bbadis.2012.03.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2011] [Revised: 03/09/2012] [Accepted: 03/12/2012] [Indexed: 01/26/2023]
Abstract
The loss of Surf1 protein leads to a severe COX deficiency manifested as a fatal neurodegenerative disorder, the Leigh syndrome (LS(COX)). Surf1 appears to be involved in the early step of COX assembly but its function remains unknown. The aim of the study was to find out how SURF1 gene mutations influence expression of OXPHOS and other pro-mitochondrial genes and to further characterize the altered COX assembly. Analysis of fibroblast cell lines from 9 patients with SURF1 mutations revealed a 70% decrease of the COX complex content to be associated with 32-54% upregulation of respiratory chain complexes I, III and V and accumulation of Cox5a subunit. Whole genome expression profiling showed a general decrease of transcriptional activity in LS(COX) cells and indicated that the adaptive changes in OXPHOS complexes are due to a posttranscriptional compensatory mechanism. Electrophoretic and WB analysis showed that in mitochondria of LS(COX) cells compared to controls, the assembled COX is present entirely in a supercomplex form, as I-III₂-IV supercomplex but not as larger supercomplexes. The lack of COX also caused an accumulation of I-III₂ supercomplex. The accumulated Cox5a was mainly present as a free subunit. We have found out that the major COX assembly subcomplexes accumulated due to SURF1 mutations range in size between approximately 85-140kDa. In addition to the originally proposed S2 intermediate they might also represent Cox1-containing complexes lacking other COX subunits. Unlike the assembled COX, subcomplexes are unable to associate with complexes I and III.
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13
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Kemp JP, Smith PM, Pyle A, Neeve VCM, Tuppen HAL, Schara U, Talim B, Topaloglu H, Holinski-Feder E, Abicht A, Czermin B, Lochmüller H, McFarland R, Chinnery PF, Chrzanowska-Lightowlers ZMA, Lightowlers RN, Taylor RW, Horvath R. Nuclear factors involved in mitochondrial translation cause a subgroup of combined respiratory chain deficiency. ACTA ACUST UNITED AC 2010; 134:183-95. [PMID: 21169334 PMCID: PMC3707321 DOI: 10.1093/brain/awq320] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
Mutations in several mitochondrial DNA and nuclear genes involved in mitochondrial protein synthesis have recently been reported in combined respiratory chain deficiency, indicating a generalized defect in mitochondrial translation. However, the number of patients with pathogenic mutations is small, implying that nuclear defects of mitochondrial translation are either underdiagnosed or intrauterine lethal. No comprehensive studies have been reported on large cohorts of patients with combined respiratory chain deficiency addressing the role of nuclear genes affecting mitochondrial protein synthesis to date. We investigated a cohort of 52 patients with combined respiratory chain deficiency without causative mitochondrial DNA mutations, rearrangements or depletion, to determine whether a defect in mitochondrial translation defines the pathomechanism of their clinical disease. We followed a combined approach of sequencing known nuclear genes involved in mitochondrial protein synthesis (EFG1, EFTu, EFTs, MRPS16, TRMU), as well as performing in vitro functional studies in 22 patient cell lines. The majority of our patients were children (<15 years), with an early onset of symptoms <1 year of age (65%). The most frequent clinical presentation was mitochondrial encephalomyopathy (63%); however, a number of patients showed cardiomyopathy (33%), isolated myopathy (15%) or hepatopathy (13%). Genomic sequencing revealed compound heterozygous mutations in the mitochondrial transfer ribonucleic acid modifying factor (TRMU) in a single patient only, presenting with early onset, reversible liver disease. No pathogenic mutation was detected in any of the remaining 51 patients in the other genes analysed. In vivo labelling of mitochondrial polypeptides in 22 patient cell lines showed overall (three patients) or selective (four patients) defects of mitochondrial translation. Immunoblotting for mitochondrial proteins revealed decreased steady state levels of proteins in some patients, but normal or increased levels in others, indicating a possible compensatory mechanism. In summary, candidate gene sequencing in this group of patients has a very low detection rate (1/52), although in vivo labelling of mitochondrial translation in 22 patient cell lines indicate that a nuclear defect affecting mitochondrial protein synthesis is responsible for about one-third of combined respiratory chain deficiencies (7/22). In the remaining patients, the impaired respiratory chain activity is most likely the consequence of several different events downstream of mitochondrial translation. Clinical classification of patients with biochemical analysis, genetic testing and, more importantly, in vivo labelling and immunoblotting of mitochondrial proteins show incoherent results, but a systematic review of these data in more patients may reveal underlying mechanisms, and facilitate the identification of novel factors involved in combined respiratory chain deficiency.
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Affiliation(s)
- John P Kemp
- Mitochondrial Research Group, Institute of Human Genetics, Newcastle University, Central Parkway, Newcastle upon Tyne NE1 3BZ, UK
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14
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Acton BM, Lai I, Shang X, Jurisicova A, Casper RF. Neutral Mitochondrial Heteroplasmy Alters Physiological Function in Mice1. Biol Reprod 2007; 77:569-76. [PMID: 17554081 DOI: 10.1095/biolreprod.107.060806] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Cytoplasmic transfer is an assisted reproductive technique that involves the infusion of ooplasm from a donor oocyte into a recipient oocyte of inferior developmental competence. Although this technique has shown some success for couples with recurrent in vitro fertilization failure, it results in mitochondrial heteroplasmy in the offspring, defined as the presence of two different mitochondrial genomes in the same individual. Because the long-term health consequences of mitochondrial heteroplasmy are unknown, there is a need for appropriate animal models to evaluate any physiological changes of dual mtDNA genotypes. This longitudinal study was designed as a preliminary screen of basic physiological functions for heteroplasmic mice (NZB mtDNA on a BALB/cByJ background). The mice were tested for cardiovascular and metabolic function, hematological parameters, body mass analysis, ovarian reserve, and tissue histologic abnormalities over a period of 15 mo. Heteroplasmic mice developed systemic hypertension that corrected over time and was accompanied by cardiac changes consistent with pulmonary hypertension. In addition, heteroplasmic animals had increased body mass and fat mass compared with controls at all ages. Finally, these animals had abnormalities in electrolytes and hematological parameters. Our findings suggest that there are significant physiological differences between heteroplasmic and control mice. Because ooplasm transfer appears to be consistently associated with mitochondrial heteroplasmy, children conceived through ooplasm transfer should be closely followed to determine if they are at risk for any health problems.
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Affiliation(s)
- B M Acton
- Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, University of Toronto, Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada M5G 1X5
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15
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Sher RB, Aoyama C, Huebsch KA, Ji S, Kerner J, Yang Y, Frankel WN, Hoppel CL, Wood PA, Vance DE, Cox GA. A Rostrocaudal Muscular Dystrophy Caused by a Defect in Choline Kinase Beta, the First Enzyme in Phosphatidylcholine Biosynthesis. J Biol Chem 2006; 281:4938-48. [PMID: 16371353 DOI: 10.1074/jbc.m512578200] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Muscular dystrophies include a diverse group of genetically heterogeneous disorders that together affect 1 in 2000 births worldwide. The diseases are characterized by progressive muscle weakness and wasting that lead to severe disability and often premature death. Rostrocaudal muscular dystrophy (rmd) is a new recessive mouse mutation that causes a rapidly progressive muscular dystrophy and a neonatal forelimb bone deformity. The rmd mutation is a 1.6-kb intragenic deletion within the choline kinase beta (Chkb) gene, resulting in a complete loss of CHKB protein and enzymatic activity. CHKB is one of two mammalian choline kinase (CHK) enzymes (alpha and beta) that catalyze the phosphorylation of choline to phosphocholine in the biosynthesis of the major membrane phospholipid phosphatidylcholine. While mutant rmd mice show a dramatic decrease of CHK activity in all tissues, the dystrophy is only evident in skeletal muscle tissues in an unusual rostral-to-caudal gradient. Minor membrane disruption similar to dysferlinopathies suggest that membrane fusion defects may underlie this dystrophy, because severe membrane disruptions are not evident as determined by creatine kinase levels, Evans Blue infiltration, and unaltered levels of proteins in the dystrophin-glycoprotein complex. The rmd mutant mouse offers the first demonstration of a defect in a phospholipid biosynthetic enzyme causing muscular dystrophy, representing a unique model for understanding mechanisms of muscle degeneration.
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MESH Headings
- Animals
- Blotting, Northern
- Carnitine O-Palmitoyltransferase/metabolism
- Catalysis
- Cell Membrane/metabolism
- Cholesterol/metabolism
- Choline Kinase/genetics
- Choline Kinase/physiology
- Chromosome Mapping
- Coloring Agents/pharmacology
- Creatine Kinase/metabolism
- Crosses, Genetic
- Dystrophin/metabolism
- Evans Blue/pharmacology
- Female
- Genotype
- Glycoproteins/metabolism
- Immunoblotting
- Lipids/chemistry
- Liver/metabolism
- Male
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Mice, Transgenic
- Microscopy, Electron
- Microscopy, Fluorescence
- Mitochondria/metabolism
- Models, Genetic
- Muscle Proteins/ultrastructure
- Muscle, Skeletal/ultrastructure
- Muscles/pathology
- Muscular Dystrophy, Animal/enzymology
- Muscular Dystrophy, Animal/pathology
- Mutation
- Phenotype
- Phosphatidylcholines/chemistry
- Physical Chromosome Mapping
- Recombination, Genetic
- Sarcolemma/ultrastructure
- Time Factors
- Triglycerides/metabolism
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Affiliation(s)
- Roger B Sher
- The Jackson Laboratory, Bar Harbor, Maine 04609, USA
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16
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Jacobs LJAM, de Wert G, Geraedts JPM, de Coo IFM, Smeets HJM. The transmission of OXPHOS disease and methods to prevent this. Hum Reprod Update 2005; 12:119-36. [PMID: 16199488 DOI: 10.1093/humupd/dmi042] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Diseases owing to defects of oxidative phosphorylation (OXPHOS) affect approximately 1 in 8,000 individuals. Clinical manifestations can be extremely variable and range from single-affected tissues to multisystemic syndromes. In general, tissues with a high energy demand, like brain, heart and muscle, are affected. The OXPHOS system is under dual genetic control, and mutations in both nuclear and mitochondrial genes can cause OXPHOS diseases. The expression and segregation of mitochondrial DNA (mtDNA) mutations is different from nuclear gene defects. The mtDNA mutations can be either homoplasmic or heteroplasmic and in the latter case disease becomes manifest when the mutation exceeds a tissue-specific threshold. This mutation load can vary between tissues and often an exact correlation between mutation load and phenotypic expression is lacking. The transmission of mtDNA mutations is exclusively maternal, but the mutation load between embryos can vary tremendously because of a segregational bottleneck. Diseases by nuclear gene mutations show a normal Mendelian inheritance pattern and often have a more constant clinical manifestation. Given the prevalence and severity of OXPHOS disorders and the lack of adequate therapy, existing and new methods for the prevention of transmission of OXPHOS disorders, like prenatal diagnosis (PND), preimplantation genetic diagnosis (PGD), cytoplasmic transfer (CT) and nuclear transfer (NT), are technically and ethically evaluated.
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Affiliation(s)
- L J A M Jacobs
- Department of Genetics and Cell Biology, University of Maastricht, 6200 MD Maastricht, The Netherlands
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17
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Tay SKH, Sacconi S, Akman HO, Morales JF, Morales A, De Vivo DC, Shanske S, Bonilla E, DiMauro S. Unusual clinical presentations in four cases of Leigh disease, cytochrome C oxidase deficiency, and SURF1 gene mutations. J Child Neurol 2005; 20:670-4. [PMID: 16225813 DOI: 10.1177/08830738050200080701] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Mutations in the SURF1 gene are the most frequent causes of Leigh disease with cytochrome c oxidase deficiency. We describe four children with novel SURF1 mutations and unusual features: three had prominent renal symptoms and one had ragged red fibers in the muscle biopsy. We identified five pathogenic mutations in SURF1: two mutations were novel, an in-frame nonsense mutation (834G-->A) and an out-of-frame duplication (820-824dupTACAT). Although renal manifestations have not been described in association with SURF1 mutations, they can be part of the clinical presentation. Likewise, mitochondrial proliferation in muscle (with ragged red fibers) is most unusual in Leigh disease but might be part of an emerging phenotype.
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Affiliation(s)
- Stacey K H Tay
- Department of Neurology, Columbia University, New York, NY, USA
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18
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Chiron S, Suleau A, Bonnefoy N. Mitochondrial translation: elongation factor tu is essential in fission yeast and depends on an exchange factor conserved in humans but not in budding yeast. Genetics 2005; 169:1891-901. [PMID: 15695360 PMCID: PMC1449603 DOI: 10.1534/genetics.104.037473] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The translation elongation factor EF-Tu is a GTPase that delivers amino-acylated tRNAs to the ribosome during the elongation step of translation. EF-Tu/GDP is recycled by the guanine nucleotide exchange factor EF-Ts. Whereas EF-Ts is lacking in S. cerevisiae, both translation factors are found in S. pombe and H. sapiens mitochondria, consistent with the known similarity between fission yeast and human cell mitochondrial physiology. We constructed yeast mutants lacking these elongation factors. We show that mitochondrial translation is vital for S. pombe, as it is for human cells. In a genetic background allowing the loss of mitochondrial functions, a block in mitochondrial translation in S. pombe leads to a major depletion of mtDNA. The relationships between EF-Ts and EF-Tu from both yeasts and humans were investigated through functional complementation and coexpression experiments and by a search for suppressors of the absence of the S. pombe EF-Ts. We find that S. cerevisiae EF-Tu is functionally equivalent to the S. pombe EF-Tu/EF-Ts couple. Point mutations in the S. pombe EF-Tu can render it independent of its exchange factor, thereby mimicking the situation in S. cerevisiae.
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Affiliation(s)
- Stéphane Chiron
- Centre de Génétique Moléculaire du CNRS, Gif-sur-Yvette, France
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19
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Miller C, Saada A, Shaul N, Shabtai N, Ben-Shalom E, Shaag A, Hershkovitz E, Elpeleg O. Defective mitochondrial translation caused by a ribosomal protein (MRPS16) mutation. Ann Neurol 2005; 56:734-8. [PMID: 15505824 DOI: 10.1002/ana.20282] [Citation(s) in RCA: 168] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The mitochondrial respiratory chain comprises 85 subunits, 13 of which are mitochondrial encoded. The synthesis of these 13 proteins requires many nuclear-encoded proteins that participate in mitochondrial DNA replication, transcript production, and a distinctive mitochondrial translation apparatus. We report a patient with agenesis of corpus callosum, dysmorphism, and fatal neonatal lactic acidosis with markedly decreased complex I and IV activity in muscle and liver and a generalized mitochondrial translation defect identified in pulse-label experiments. The defect was associated with marked reduction of the 12S rRNA transcript level likely attributed to a nonsense mutation in the MRPS16 gene. A new group of mitochondrial respiratory chain disorders is proposed, resulting from mutations in nuclear encoded components of the mitochondrial translation apparatus.
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Affiliation(s)
- Chaya Miller
- Metabolic Disease Unit, Shaare-Zedek Medical Center, Jerusalem, Israel
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20
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Limongelli A, Schaefer J, Jackson S, Invernizzi F, Kirino Y, Suzuki T, Reichmann H, Zeviani M. Variable penetrance of a familial progressive necrotising encephalopathy due to a novel tRNA(Ile) homoplasmic mutation in the mitochondrial genome. J Med Genet 2004; 41:342-9. [PMID: 15121771 PMCID: PMC1735786 DOI: 10.1136/jmg.2003.016048] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
INTRODUCTION We present a family comprising a clinically normal mother and two daughters, each with severe encephalopathy with onset in late childhood. A third daughter had died previously of an earlier onset but neuropathologically similar disease. METHODS Sequence analysis of the entire mtDNA was carried out in muscle, fibroblasts, and lymphocytes of the affected daughters and unaffected mother. Biochemical analysis of individual respiratory chain enzymes was performed on the same tissues, and on several transmitochondrial cybrid clones containing the nucleus of a 143B.206 osteosarcoma cell line and the mutant mtDNA. RESULTS Genetic analyses revealed in both daughters and mother the presence of a novel mutation in the tRNA(Ile) gene of mtDNA, which was homoplasmic in fibroblasts, lymphocytes, and skeletal muscle of the two patients. It was also homoplasmic in fibroblast and skeletal muscle samples of the mother, and approximately 97% heteroplasmic in her lymphocytes. Combined defects of complexes I and IV of the mitochondrial respiratory chain were found not only in fibroblasts of the two probands, but surprisingly also in those of their clinically unaffected mother. The respiratory chain defect segregated in transmitochondrial cybrids containing the nucleus of a 143B.206 osteosarcoma cell line and the mutant mtDNA, indicating that the latter was responsible for the biochemical phenotype. DISCUSSION Our results support the concept that homoplasmic mutations in tRNA genes can be responsible for mitochondrial disorders characterised by extremely variable penetrance. Albeit still unexplained, this phenomenon has important consequences in the nosological characterisation, clinical management, and genetic counselling of mitochondrial disorders.
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MESH Headings
- Adolescent
- Base Sequence
- Brain Diseases, Metabolic, Inborn/diagnosis
- Brain Diseases, Metabolic, Inborn/enzymology
- Brain Diseases, Metabolic, Inborn/genetics
- Cell Line
- Child
- DNA Mutational Analysis
- DNA, Mitochondrial/genetics
- Electron Transport Complex IV/metabolism
- Female
- Fibroblasts/enzymology
- Genome, Human
- Humans
- Infant
- Middle Aged
- Mitochondrial Diseases/diagnosis
- Mitochondrial Diseases/genetics
- Molecular Sequence Data
- Muscle, Skeletal/enzymology
- Pedigree
- Penetrance
- Point Mutation
- Protein Biosynthesis
- RNA, Transfer, Ile/genetics
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Affiliation(s)
- A Limongelli
- Unit of Molecular Neurogenetics-Pierfranco and Luisa Mariani Centre for the Study of Children's Mitochondrial Disorders, National Neurological Institute Carlo Besta, Milan, Italy
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21
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Abstract
Following the discovery in the early 1960s that mitochondria contain their own DNA (mtDNA), there were two major advances, both in the 1980s: the human mtDNA sequence was published in 1981, and in 1988 the first pathogenic mtDNA mutations were identified. The floodgates were opened, and the 1990s became the decade of the mitochondrial genome. There has been a change of emphasis in the first few years of the new millennium, away from the "magic circle" of mtDNA and back to the nuclear genome. Various nuclear genes have been identified that are fundamentally important for mitochondrial homeostasis, and when these genes are disrupted, they cause autosomally inherited mitochondrial disease. Moreover, mitochondrial dysfunction plays an important role in the pathophysiology of several well established nuclear genetic disorders, such as dominant optic atrophy (mutations in OPA1), Friedreich's ataxia (FRDA), hereditary spastic paraplegia (SPG7), and Wilson's disease (ATP7B). The next major challenge is to define the more subtle interactions between nuclear and mitochondrial genes in health and disease.
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Affiliation(s)
- P F Chinnery
- Department of Neurology, The University of Newcastle upon Tyne, Newcastle upon Tyne, UK.
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