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Guo M, He Y, Chen A, Zhuang Z, Pan X, Guan M. Clinical and genetic analysis of essential hypertension with mitochondrial tRNA Met 4435A>G and YARS2 mutation. Zhejiang Da Xue Xue Bao Yi Xue Ban 2024; 53:184-193. [PMID: 38562030 PMCID: PMC11057996 DOI: 10.3724/zdxbyxb-2023-0571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Accepted: 02/23/2024] [Indexed: 04/04/2024]
Abstract
OBJECTIVES To investigate the role of m.4435A>G and YARS2 c.572G>T (p.G191V) mutations in the development of essential hypertension. METHODS A hypertensive patient with m.4435A>G and YARS2 p.G191V mutations was identified from previously collected mitochondrial genome and exon sequencing data. Clinical data were collected, and a molecular genetic study was conducted in the proband and his family members. Peripheral venous blood was collected, and immortalized lymphocyte lines constructed. The mitochondrial transfer RNA (tRNA), mitochondrial protein, adenosine triphosphate (ATP), mitochondrial membrane potential (MMP), and reactive oxygen species (ROS) in the constructed lymphocyte cell lines were measured. RESULTS Mitochondrial genome sequencing showed that all maternal members carried a highly conserved m.4435A>G mutation. The m.4435A>G mutation might affect the secondary structure and folding free energy of mitochondrial tRNA and change its stability, which may influence the anticodon ring structure. Compared with the control group, the cell lines carrying m.4435A>G and YARS2 p.G191V mutations had decreased mitochondrial tRNA homeostasis, mitochondrial protein expression, ATP production and MMP levels, as well as increased ROS levels (all P<0.05). CONCLUSIONS The YARS2 p.G191V mutation aggravates the changes in mitochondrial translation and mitochondrial function caused by m.4435A>G through affecting the steady-state level of mitochondrial tRNA and further leads to cell dysfunction, indicating that YARS2 p.G191V and m.4435A>G mutations have a synergistic effect in this family and jointly participate in the occurrence and development of essential hypertension.
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Affiliation(s)
- Meili Guo
- Clinical Laboratory, Cangnan County People's Hospital, Wenzhou 325800, Zhejiang Province, China.
| | - Yunfan He
- Institute of Genetics, Zhejiang University, Zhejiang Provincial Key Lab of Genetic and Developmental Disorders, Hangzhou 310058, China
| | - Ade Chen
- Clinical Laboratory, Cangnan County People's Hospital, Wenzhou 325800, Zhejiang Province, China
| | - Zaishou Zhuang
- Clinical Laboratory, Cangnan County People's Hospital, Wenzhou 325800, Zhejiang Province, China
| | - Xiaoyong Pan
- Clinical Laboratory, Cangnan County People's Hospital, Wenzhou 325800, Zhejiang Province, China
| | - Minxin Guan
- Institute of Genetics, Zhejiang University, Zhejiang Provincial Key Lab of Genetic and Developmental Disorders, Hangzhou 310058, China.
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2
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Purandare N, Ghosalkar E, Grossman LI, Aras S. Mitochondrial Oxidative Phosphorylation in Viral Infections. Viruses 2023; 15:2380. [PMID: 38140621 PMCID: PMC10747082 DOI: 10.3390/v15122380] [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: 10/25/2023] [Revised: 11/26/2023] [Accepted: 11/29/2023] [Indexed: 12/24/2023] Open
Abstract
Mitochondria have been identified as the "powerhouse" of the cell, generating the cellular energy, ATP, for almost seven decades. Research over time has uncovered a multifaceted role of the mitochondrion in processes such as cellular stress signaling, generating precursor molecules, immune response, and apoptosis to name a few. Dysfunctional mitochondria resulting from a departure in homeostasis results in cellular degeneration. Viruses hijack host cell machinery to facilitate their own replication in the absence of a bonafide replication machinery. Replication being an energy intensive process necessitates regulation of the host cell oxidative phosphorylation occurring at the electron transport chain in the mitochondria to generate energy. Mitochondria, therefore, can be an attractive therapeutic target by limiting energy for viral replication. In this review we focus on the physiology of oxidative phosphorylation and on the limited studies highlighting the regulatory effects viruses induce on the electron transport chain.
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Affiliation(s)
- Neeraja Purandare
- Center for Molecular Medicine and Genetics, School of Medicine, Wayne State University, Detroit, MI 48201, USA; (N.P.); (E.G.); (L.I.G.)
| | - Esha Ghosalkar
- Center for Molecular Medicine and Genetics, School of Medicine, Wayne State University, Detroit, MI 48201, USA; (N.P.); (E.G.); (L.I.G.)
| | - Lawrence I. Grossman
- Center for Molecular Medicine and Genetics, School of Medicine, Wayne State University, Detroit, MI 48201, USA; (N.P.); (E.G.); (L.I.G.)
| | - Siddhesh Aras
- Center for Molecular Medicine and Genetics, School of Medicine, Wayne State University, Detroit, MI 48201, USA; (N.P.); (E.G.); (L.I.G.)
- Department of Obstetrics and Gynecology, School of Medicine, Wayne State University, Detroit, MI 48201, USA
- Department of Oncology, School of Medicine, Wayne State University, Detroit, MI 48201, USA
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3
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Prajapat SK, Maharana KC, Singh S. Mitochondrial dysfunction in the pathogenesis of endothelial dysfunction. Mol Cell Biochem 2023:10.1007/s11010-023-04835-8. [PMID: 37642880 DOI: 10.1007/s11010-023-04835-8] [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: 06/08/2023] [Accepted: 08/14/2023] [Indexed: 08/31/2023]
Abstract
Cardiovascular diseases (CVDs) are a matter of concern worldwide, and mitochondrial dysfunction is one of the major contributing factors. Vascular endothelial dysfunction has a major role in the development of atherosclerosis because of the abnormal chemokine secretion, inflammatory mediators, enhancement of LDL oxidation, cytokine elevation, and smooth muscle cell proliferation. Endothelial cells transfer oxygen from the pulmonary circulatory system to the tissue surrounding the blood vessels, and a majority of oxygen is transferred to the myocardium by endothelial cells, which utilise a small amount of oxygen to generate ATP. Free radicals of oxide are produced by mitochondria, which are responsible for cellular oxygen uptake. Increased mitochondrial ROS generation and reduction in agonist-stimulated eNOS activation and nitric oxide bioavailability were directly linked to the observed change in mitochondrial dynamics, resulting in various CVDs and endothelial dysfunction. Presently, the manuscript mainly focuses on endothelial dysfunction, providing a deep understanding of the various features of mitochondrial mechanisms that are used to modulate endothelial dysfunction. We talk about recent findings and approaches that may make it possible to detect mitochondrial dysfunction as a potential biomarker for risk assessment and diagnosis of endothelial dysfunction. In the end, we cover several targets that may reduce mitochondrial dysfunction through both direct and indirect processes and assess the impact of several different classes of drugs in the context of endothelial dysfunction.
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Affiliation(s)
- Suresh Kumar Prajapat
- National Institute of Pharmaceutical Education and Research, Export Promotion Industrial Park (EPIP) Zandaha Road, Hajipur, Bihar, India
| | - Krushna Ch Maharana
- National Institute of Pharmaceutical Education and Research, Export Promotion Industrial Park (EPIP) Zandaha Road, Hajipur, Bihar, India
| | - Sanjiv Singh
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research, Export Promotions Industrial Park (EPIP), Industrial Area, Dist: Vaishali, Hajipur, Bihar, 844102, India.
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4
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Del Giudice L, Pontieri P, Aletta M, Calcagnile M. Mitochondrial Neurodegenerative Diseases: Three Mitochondrial Ribosomal Proteins as Intermediate Stage in the Pathway That Associates Damaged Genes with Alzheimer's and Parkinson's. BIOLOGY 2023; 12:972. [PMID: 37508402 PMCID: PMC10376763 DOI: 10.3390/biology12070972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 06/29/2023] [Accepted: 06/30/2023] [Indexed: 07/30/2023]
Abstract
Currently, numerous research endeavors are dedicated to unraveling the intricate nature of neurodegenerative diseases. These conditions are characterized by the gradual and progressive impairment of specific neuronal systems that exhibit anatomical or physiological connections. In particular, in the last twenty years, remarkable efforts have been made to elucidate neurodegenerative disorders such as Alzheimer's disease and Parkinson's disease. However, despite extensive research endeavors, no cure or effective treatment has been discovered thus far. With the emergence of studies shedding light on the contribution of mitochondria to the onset and advancement of mitochondrial neurodegenerative disorders, researchers are now directing their investigations toward the development of therapies. These therapies include molecules designed to protect mitochondria and neurons from the detrimental effects of aging, as well as mutant proteins. Our objective is to discuss and evaluate the recent discovery of three mitochondrial ribosomal proteins linked to Alzheimer's and Parkinson's diseases. These proteins represent an intermediate stage in the pathway connecting damaged genes to the two mitochondrial neurological pathologies. This discovery potentially could open new avenues for the production of medicinal substances with curative potential for the treatment of these diseases.
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Affiliation(s)
- Luigi Del Giudice
- Istituto di Bioscienze e BioRisorse-UOS Napoli-CNR c/o Dipartimento di Biologia, Sezione di Igiene, 80134 Napoli, Italy
| | - Paola Pontieri
- Istituto di Bioscienze e BioRisorse-UOS Napoli-CNR c/o Dipartimento di Biologia, Sezione di Igiene, 80134 Napoli, Italy
| | | | - Matteo Calcagnile
- Dipartimento di Scienze e Tecnologie Biologiche e Ambientali, Università del Salento, 73100 Lecce, Italy
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5
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Kobayashi A, Takeiwa T, Ikeda K, Inoue S. Roles of Noncoding RNAs in Regulation of Mitochondrial Electron Transport Chain and Oxidative Phosphorylation. Int J Mol Sci 2023; 24:ijms24119414. [PMID: 37298366 DOI: 10.3390/ijms24119414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 05/23/2023] [Accepted: 05/25/2023] [Indexed: 06/12/2023] Open
Abstract
The mitochondrial electron transport chain (ETC) plays an essential role in energy production by inducing oxidative phosphorylation (OXPHOS) to drive numerous biochemical processes in eukaryotic cells. Disorders of ETC and OXPHOS systems are associated with mitochondria- and metabolism-related diseases, including cancers; thus, a comprehensive understanding of the regulatory mechanisms of ETC and OXPHOS systems is required. Recent studies have indicated that noncoding RNAs (ncRNAs) play key roles in mitochondrial functions; in particular, some ncRNAs have been shown to modulate ETC and OXPHOS systems. In this review, we introduce the emerging roles of ncRNAs, including microRNAs (miRNAs), transfer-RNA-derived fragments (tRFs), long ncRNAs (lncRNAs), and circular RNAs (circRNAs), in the mitochondrial ETC and OXPHOS regulation.
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Affiliation(s)
- Ami Kobayashi
- Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, 60 Fenwood Rd., Boston, MA 02115, USA
- Department of Systems Aging Science and Medicine, Tokyo Metropolitan Institute for Geriatrics and Gerontology, Itabashi-ku, Tokyo 173-0015, Japan
| | - Toshihiko Takeiwa
- Department of Systems Aging Science and Medicine, Tokyo Metropolitan Institute for Geriatrics and Gerontology, Itabashi-ku, Tokyo 173-0015, Japan
| | - Kazuhiro Ikeda
- Division of Systems Medicine & Gene Therapy, Saitama Medical University, Hidaka 350-1241, Japan
| | - Satoshi Inoue
- Department of Systems Aging Science and Medicine, Tokyo Metropolitan Institute for Geriatrics and Gerontology, Itabashi-ku, Tokyo 173-0015, Japan
- Division of Systems Medicine & Gene Therapy, Saitama Medical University, Hidaka 350-1241, Japan
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6
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Varte V, Munkelwitz JW, Rincon-Limas DE. Insights from Drosophila on Aβ- and tau-induced mitochondrial dysfunction: mechanisms and tools. Front Neurosci 2023; 17:1184080. [PMID: 37139514 PMCID: PMC10150963 DOI: 10.3389/fnins.2023.1184080] [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: 03/10/2023] [Accepted: 03/31/2023] [Indexed: 05/05/2023] Open
Abstract
Alzheimer's disease (AD) is the most prevalent neurodegenerative dementia in older adults worldwide. Sadly, there are no disease-modifying therapies available for treatment due to the multifactorial complexity of the disease. AD is pathologically characterized by extracellular deposition of amyloid beta (Aβ) and intracellular neurofibrillary tangles composed of hyperphosphorylated tau. Increasing evidence suggest that Aβ also accumulates intracellularly, which may contribute to the pathological mitochondrial dysfunction observed in AD. According with the mitochondrial cascade hypothesis, mitochondrial dysfunction precedes clinical decline and thus targeting mitochondria may result in new therapeutic strategies. Unfortunately, the precise mechanisms connecting mitochondrial dysfunction with AD are largely unknown. In this review, we will discuss how the fruit fly Drosophila melanogaster is contributing to answer mechanistic questions in the field, from mitochondrial oxidative stress and calcium dysregulation to mitophagy and mitochondrial fusion and fission. In particular, we will highlight specific mitochondrial insults caused by Aβ and tau in transgenic flies and will also discuss a variety of genetic tools and sensors available to study mitochondrial biology in this flexible organism. Areas of opportunity and future directions will be also considered.
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Affiliation(s)
- Vanlalrinchhani Varte
- Department of Neurology, McKnight Brain Institute, Norman Fixel Institute for Neurological Diseases, University of Florida, Gainesville, FL, United States
| | - Jeremy W. Munkelwitz
- Department of Neurology, McKnight Brain Institute, Norman Fixel Institute for Neurological Diseases, University of Florida, Gainesville, FL, United States
| | - Diego E. Rincon-Limas
- Department of Neurology, McKnight Brain Institute, Norman Fixel Institute for Neurological Diseases, University of Florida, Gainesville, FL, United States
- Department of Neuroscience, University of Florida, Gainesville, FL, United States
- Genetics Institute, University of Florida, Gainesville, FL, United States
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7
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Van Haute L, O'Connor E, Díaz-Maldonado H, Munro B, Polavarapu K, Hock DH, Arunachal G, Athanasiou-Fragkouli A, Bardhan M, Barth M, Bonneau D, Brunetti-Pierri N, Cappuccio G, Caruana NJ, Dominik N, Goel H, Helman G, Houlden H, Lenaers G, Mention K, Murphy D, Nandeesh B, Olimpio C, Powell CA, Preethish-Kumar V, Procaccio V, Rius R, Rebelo-Guiomar P, Simons C, Vengalil S, Zaki MS, Ziegler A, Thorburn DR, Stroud DA, Maroofian R, Christodoulou J, Gustafsson C, Nalini A, Lochmüller H, Minczuk M, Horvath R. TEFM variants impair mitochondrial transcription causing childhood-onset neurological disease. Nat Commun 2023; 14:1009. [PMID: 36823193 PMCID: PMC9950373 DOI: 10.1038/s41467-023-36277-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 01/20/2023] [Indexed: 02/25/2023] Open
Abstract
Mutations in the mitochondrial or nuclear genomes are associated with a diverse group of human disorders characterized by impaired mitochondrial respiration. Within this group, an increasing number of mutations have been identified in nuclear genes involved in mitochondrial RNA biology. The TEFM gene encodes the mitochondrial transcription elongation factor responsible for enhancing the processivity of mitochondrial RNA polymerase, POLRMT. We report for the first time that TEFM variants are associated with mitochondrial respiratory chain deficiency and a wide range of clinical presentations including mitochondrial myopathy with a treatable neuromuscular transmission defect. Mechanistically, we show muscle and primary fibroblasts from the affected individuals have reduced levels of promoter distal mitochondrial RNA transcripts. Finally, tefm knockdown in zebrafish embryos resulted in neuromuscular junction abnormalities and abnormal mitochondrial function, strengthening the genotype-phenotype correlation. Our study highlights that TEFM regulates mitochondrial transcription elongation and its defect results in variable, tissue-specific neurological and neuromuscular symptoms.
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Affiliation(s)
- Lindsey Van Haute
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, CB2 0XY, UK
| | - Emily O'Connor
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, ON, Canada
- Division of Neurology, Department of Medicine, The Ottawa Hospital, Ottawa, ON, Canada
| | - Héctor Díaz-Maldonado
- Department of Biochemistry and Cell Biology, University of Gothenburg, SE-405 30, Gothenburg, Sweden
| | - Benjamin Munro
- Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge, UK
| | - Kiran Polavarapu
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, ON, Canada
- Division of Neurology, Department of Medicine, The Ottawa Hospital, Ottawa, ON, Canada
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, India
| | - Daniella H Hock
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Road, Parkville, VIC, 3052, Australia
| | - Gautham Arunachal
- Department of Human genetics, National Institute of Mental Health and Neurosciences, Bengaluru, India
| | - Alkyoni Athanasiou-Fragkouli
- UCL London, Department of Neuromuscular Disorders, Institute of Neurology, University College London, London, UK
| | - Mainak Bardhan
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, India
| | - Magalie Barth
- Department of Genetics, Mitovasc INSERM 1083, CNRS 6015, University Hospital of Angers, Angers, France
| | - Dominique Bonneau
- Department of Genetics, Mitovasc INSERM 1083, CNRS 6015, University Hospital of Angers, Angers, France
| | - Nicola Brunetti-Pierri
- Department of Translational Medicine, University of Naples Federico II, Via s. Pansini, 5, 80131, Naples, Italy
| | - Gerarda Cappuccio
- Department of Translational Medicine, University of Naples Federico II, Via s. Pansini, 5, 80131, Naples, Italy
| | - Nikeisha J Caruana
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Road, Parkville, VIC, 3052, Australia
- Institute for Health and Sport (IHES), Victoria University, Melbourne, VIC, 3011, Australia
| | - Natalia Dominik
- UCL London, Department of Neuromuscular Disorders, Institute of Neurology, University College London, London, UK
| | - Himanshu Goel
- Hunter Genetics, Waratah, University of Newcastle, Callaghan, NSW, 2298, Australia
| | - Guy Helman
- Murdoch Children's Research Institute, 50 Flemington Road, Parkville, VIC, 3052, Australia
| | - Henry Houlden
- UCL London, Department of Neuromuscular Disorders, Institute of Neurology, University College London, London, UK
| | - Guy Lenaers
- Department of Genetics, Mitovasc INSERM 1083, CNRS 6015, University Hospital of Angers, Angers, France
| | - Karine Mention
- Pediatric Inherited Metabolic Disorders, Hôpital Jeanne de Flandre, Lille, France
| | - David Murphy
- UCL London, Department of Neuromuscular Disorders, Institute of Neurology, University College London, London, UK
| | - Bevinahalli Nandeesh
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, India
- Department of Neuropathology, National Institute of Mental Health and Neurosciences, Bengaluru, India
| | - Catarina Olimpio
- Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge, UK
| | | | | | - Vincent Procaccio
- Department of Genetics, Mitovasc INSERM 1083, CNRS 6015, University Hospital of Angers, Angers, France
| | - Rocio Rius
- Murdoch Children's Research Institute, 50 Flemington Road, Parkville, VIC, 3052, Australia
- Department of Paediatrics, University of Melbourne, Parkville, VIC, 3010, Australia
| | | | - Cas Simons
- Murdoch Children's Research Institute, 50 Flemington Road, Parkville, VIC, 3052, Australia
| | - Seena Vengalil
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, India
| | - Maha S Zaki
- Clinical Genetics Department, Human Genetics and Genome Research Division, National Research Centre, Cairo, 12311, Egypt
| | - Alban Ziegler
- Department of Genetics, Mitovasc INSERM 1083, CNRS 6015, University Hospital of Angers, Angers, France
| | - David R Thorburn
- Murdoch Children's Research Institute, 50 Flemington Road, Parkville, VIC, 3052, Australia
- Department of Paediatrics, University of Melbourne, Parkville, VIC, 3010, Australia
| | - David A Stroud
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Road, Parkville, VIC, 3052, Australia
- Murdoch Children's Research Institute, 50 Flemington Road, Parkville, VIC, 3052, Australia
| | - Reza Maroofian
- UCL London, Department of Neuromuscular Disorders, Institute of Neurology, University College London, London, UK
| | - John Christodoulou
- Murdoch Children's Research Institute, 50 Flemington Road, Parkville, VIC, 3052, Australia
- Department of Paediatrics, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Claes Gustafsson
- Department of Biochemistry and Cell Biology, University of Gothenburg, SE-405 30, Gothenburg, Sweden
| | - Atchayaram Nalini
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, India
| | - Hanns Lochmüller
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, ON, Canada
- Division of Neurology, Department of Medicine, The Ottawa Hospital, Ottawa, ON, Canada
| | - Michal Minczuk
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, CB2 0XY, UK.
| | - Rita Horvath
- Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge, UK.
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Paciello F, Ripoli C, Fetoni AR, Grassi C. Redox Imbalance as a Common Pathogenic Factor Linking Hearing Loss and Cognitive Decline. Antioxidants (Basel) 2023; 12:antiox12020332. [PMID: 36829891 PMCID: PMC9952092 DOI: 10.3390/antiox12020332] [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: 01/23/2023] [Accepted: 01/29/2023] [Indexed: 02/04/2023] Open
Abstract
Experimental and clinical data suggest a tight link between hearing and cognitive functions under both physiological and pathological conditions. Indeed, hearing perception requires high-level cognitive processes, and its alterations have been considered a risk factor for cognitive decline. Thus, identifying common pathogenic determinants of hearing loss and neurodegenerative disease is challenging. Here, we focused on redox status imbalance as a possible common pathological mechanism linking hearing and cognitive dysfunctions. Oxidative stress plays a critical role in cochlear damage occurring during aging, as well as in that induced by exogenous factors, including noise. At the same time, increased oxidative stress in medio-temporal brain regions, including the hippocampus, is a hallmark of neurodegenerative disorders like Alzheimer's disease. As such, antioxidant therapy seems to be a promising approach to prevent and/or counteract both sensory and cognitive neurodegeneration. Here, we review experimental evidence suggesting that redox imbalance is a key pathogenetic factor underlying the association between sensorineural hearing loss and neurodegenerative diseases. A greater understanding of the pathophysiological mechanisms shared by these two diseased conditions will hopefully provide relevant information to develop innovative and effective therapeutic strategies.
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Affiliation(s)
- Fabiola Paciello
- Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
| | - Cristian Ripoli
- Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
- Correspondence: ; Tel.: +39-0630154966
| | - Anna Rita Fetoni
- Unit of Audiology, Department of Neuroscience, Università degli Studi di Napoli Federico II, 80138 Naples, Italy
| | - Claudio Grassi
- Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
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9
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He P, Wang Q, Hong X, Yuan H. Novel TARS2 variant identified in a Chinese patient with mitochondrial encephalomyopathy and a systematic review. Am J Med Genet A 2023; 191:70-76. [PMID: 36218002 DOI: 10.1002/ajmg.a.62988] [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: 06/22/2022] [Revised: 09/15/2022] [Accepted: 09/24/2022] [Indexed: 12/14/2022]
Abstract
Biallelic pathogenic variants in the TARS2 gene cause combined oxidative phosphorylation deficiency, subtype 21 (COXPD21, MIM #615918), which is a rare mitochondrial encephalomyopathy (ME) characterized by early-onset severe axial hypotonia, limb hypertonia, delayed psychomotor development, epilepsy, and brain anomalies. Currently, eight COXPD21 patients have been reported in the literature, and 11 pathogenic variants in TARS2 have been identified. Here, we report a 2-year-6-month-old Chinese female who presented with severe dystonia, developmental regression, absent speech, and intractable epilepsy. Laboratory examination showed persistently increased serum lactate. Brain MRI showed that the head of the caudate and partial lenticular nucleus were bilateral symmetrical T2-weighted imaging (T2WI) hyperintense and the corpus callosum was very thin. The clinical characteristics pointed to a ME. Trio-based whole-exome sequencing (WES) was employed to detect the causative variants. WES revealed novel compound heterozygous variants, c.470G>C (p.Thr157Arg) and c.2051C>T (p.Arg684Gln), in TARS2 in our patient that were inherited from the mother and father, respectively. Next, we systematically reviewed the available clinical features of COXPD21 patients and noticed that the reduced fetal movement observed in our patient may be a novel phenotype of COXPD21. These findings expand the mutation spectrum of TARS2 and provide insights into the genotype-phenotype relationship in COXPD21 as well as a foundation for its genetic counseling, diagnosis and treatment.
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Affiliation(s)
- Peiqing He
- Affiliated Dongguan Maternal and Child Health Care Hospital, Southern Medical University, Dongguan, China.,Dongguan Institute of Reproductive and Genetic Research, Dongguan, China
| | - Qingming Wang
- Affiliated Dongguan Maternal and Child Health Care Hospital, Southern Medical University, Dongguan, China.,Dongguan Institute of Reproductive and Genetic Research, Dongguan, China
| | - Xiaochun Hong
- Affiliated Dongguan Maternal and Child Health Care Hospital, Southern Medical University, Dongguan, China
| | - Haiming Yuan
- Affiliated Dongguan Maternal and Child Health Care Hospital, Southern Medical University, Dongguan, China.,Dongguan Institute of Reproductive and Genetic Research, Dongguan, China
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10
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Del Greco C, Antonellis A. The Role of Nuclear-Encoded Mitochondrial tRNA Charging Enzymes in Human Inherited Disease. Genes (Basel) 2022; 13:genes13122319. [PMID: 36553587 PMCID: PMC9777667 DOI: 10.3390/genes13122319] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 11/30/2022] [Accepted: 12/02/2022] [Indexed: 12/13/2022] Open
Abstract
Aminoacyl-tRNA synthetases (ARSs) are highly conserved essential enzymes that charge tRNA with cognate amino acids-the first step of protein synthesis. Of the 37 nuclear-encoded human ARS genes, 17 encode enzymes are exclusively targeted to the mitochondria (mt-ARSs). Mutations in nuclear mt-ARS genes are associated with rare, recessive human diseases with a broad range of clinical phenotypes. While the hypothesized disease mechanism is a loss-of-function effect, there is significant clinical heterogeneity among patients that have mutations in different mt-ARS genes and also among patients that have mutations in the same mt-ARS gene. This observation suggests that additional factors are involved in disease etiology. In this review, we present our current understanding of diseases caused by mutations in the genes encoding mt-ARSs and propose explanations for the observed clinical heterogeneity.
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Affiliation(s)
- Christina Del Greco
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Anthony Antonellis
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI 48109, USA
- Department of Neurology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
- Correspondence:
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11
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Cohen T, Medini H, Mordechai C, Eran A, Mishmar D. Human mitochondrial RNA modifications associate with tissue-specific changes in gene expression, and are affected by sunlight and UV exposure. Eur J Hum Genet 2022; 30:1363-1372. [PMID: 35246665 PMCID: PMC9712611 DOI: 10.1038/s41431-022-01072-3] [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: 06/27/2021] [Revised: 01/30/2022] [Accepted: 02/10/2022] [Indexed: 11/08/2022] Open
Abstract
RNA-DNA differences (RDD) have previously been identified in the human mitochondrial RNA (mt-RNA) transcripts, yet their functional impact is poorly understood. By analyzing 4928 RNA-seq samples from 23 body sites, we found that mtDNA gene expression negatively correlated with the levels of both m1A 947 16 S rRNA modification (mtDNA position 2617) and the m1A 1812 ND5 mRNA modification (mtDNA position 13,710) in 15 and 14 body sites, respectively. Such correlation was not evident in all tested brain tissues, thus suggesting a tissue-specific impact of these modifications on mtDNA gene expression. To assess the response of the tested modifications to environmental cues, we analyzed pairs of skin samples that were either exposed to the sun or not. We found that the correlations of mtDNA gene expression with both mt-RNA modifications were compromised upon sun exposure. As a first step to explore the underlying mechanism, we analyzed RNA-seq data from keratinocytes that were exposed to increasing doses of UV irradiation. Similar to sun exposure, we found a significant decrease in mtDNA gene expression upon increase in UV dosage. In contrast, there was a significant increase in the m1A 947 16 S rRNA modification levels upon elevation in UV dose. Finally, we identified candidate modulators of such responses. Taken together, our results indicate that mt-RNA modifications functionally correlate with mtDNA gene expression, and responds to environmental cues, hence supporting their physiological importance.
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Affiliation(s)
- Tal Cohen
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, 8410501, Israel
| | - Hadar Medini
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, 8410501, Israel
| | - Chen Mordechai
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, 8410501, Israel
| | - Alal Eran
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, 8410501, Israel
| | - Dan Mishmar
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, 8410501, Israel.
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12
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Putscher E, Hecker M, Fitzner B, Boxberger N, Schwartz M, Koczan D, Lorenz P, Zettl UK. Genetic risk variants for multiple sclerosis are linked to differences in alternative pre-mRNA splicing. Front Immunol 2022; 13:931831. [PMID: 36405756 PMCID: PMC9670805 DOI: 10.3389/fimmu.2022.931831] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 10/12/2022] [Indexed: 08/04/2023] Open
Abstract
BACKGROUND Multiple sclerosis (MS) is a chronic immune-mediated disease of the central nervous system to which a genetic predisposition contributes. Over 200 genetic regions have been associated with increased disease risk, but the disease-causing variants and their functional impact at the molecular level are mostly poorly defined. We hypothesized that single-nucleotide polymorphisms (SNPs) have an impact on pre-mRNA splicing in MS. METHODS Our study focused on 10 bioinformatically prioritized SNP-gene pairs, in which the SNP has a high potential to alter alternative splicing events (ASEs). We tested for differential gene expression and differential alternative splicing in B cells from MS patients and healthy controls. We further examined the impact of the SNP genotypes on ASEs and on splice isoform expression levels. Novel genotype-dependent effects on splicing were verified with splicing reporter minigene assays. RESULTS We were able to confirm previously described findings regarding the relation of MS-associated SNPs with the ASEs of the pre-mRNAs from GSDMB and SP140. We also observed an increased IL7R exon 6 skipping when comparing relapsing and progressive MS patients to healthy subjects. Moreover, we found evidence that the MS risk alleles of the SNPs rs3851808 (EFCAB13), rs1131123 (HLA-C), rs10783847 (TSFM), and rs2014886 (TSFM) may contribute to a differential splicing pattern. Of particular interest is the genotype-dependent exon skipping of TSFM due to the SNP rs2014886. The minor allele T creates a donor splice site, resulting in the expression of the exon 3 and 4 of a short TSFM transcript isoform, whereas in the presence of the MS risk allele C, this donor site is absent, and thus the short transcript isoform is not expressed. CONCLUSION In summary, we found that genetic variants from MS risk loci affect pre-mRNA splicing. Our findings substantiate the role of ASEs with respect to the genetics of MS. Further studies on how disease-causing genetic variants may modify the interactions between splicing regulatory sequence elements and RNA-binding proteins can help to deepen our understanding of the genetic susceptibility to MS.
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Affiliation(s)
- Elena Putscher
- Rostock University Medical Center, Department of Neurology, Division of Neuroimmunology, Rostock, Germany
| | - Michael Hecker
- Rostock University Medical Center, Department of Neurology, Division of Neuroimmunology, Rostock, Germany
| | - Brit Fitzner
- Rostock University Medical Center, Department of Neurology, Division of Neuroimmunology, Rostock, Germany
| | - Nina Boxberger
- Rostock University Medical Center, Department of Neurology, Division of Neuroimmunology, Rostock, Germany
| | - Margit Schwartz
- Rostock University Medical Center, Department of Neurology, Division of Neuroimmunology, Rostock, Germany
| | - Dirk Koczan
- Rostock University Medical Center, Institute of Immunology, Rostock, Germany
| | - Peter Lorenz
- Rostock University Medical Center, Institute of Immunology, Rostock, Germany
| | - Uwe Klaus Zettl
- Rostock University Medical Center, Department of Neurology, Division of Neuroimmunology, Rostock, Germany
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13
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Marmolejo-Garza A, Medeiros-Furquim T, Rao R, Eggen BJL, Boddeke E, Dolga AM. Transcriptomic and epigenomic landscapes of Alzheimer's disease evidence mitochondrial-related pathways. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2022; 1869:119326. [PMID: 35839870 DOI: 10.1016/j.bbamcr.2022.119326] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 07/06/2022] [Accepted: 07/07/2022] [Indexed: 02/06/2023]
Abstract
Alzheimers disease (AD) is the main cause of dementia and it is defined by cognitive decline coupled to extracellular deposit of amyloid-beta protein and intracellular hyperphosphorylation of tau protein. Historically, efforts to target such hallmarks have failed in numerous clinical trials. In addition to these hallmark-targeted approaches, several clinical trials focus on other AD pathological processes, such as inflammation, mitochondrial dysfunction, and oxidative stress. Mitochondria and mitochondrial-related mechanisms have become an attractive target for disease-modifying strategies, as mitochondrial dysfunction prior to clinical onset has been widely described in AD patients and AD animal models. Mitochondrial function relies on both the nuclear and mitochondrial genome. Findings from omics technologies have shed light on AD pathophysiology at different levels (e.g., epigenome, transcriptome and proteome). Most of these studies have focused on the nuclear-encoded components. The first part of this review provides an updated overview of the mechanisms that regulate mitochondrial gene expression and function. The second part of this review focuses on evidence of mitochondrial dysfunction in AD. We have focused on published findings and datasets that study AD. We analyzed published data and provide examples for mitochondrial-related pathways. These pathways are strikingly dysregulated in AD neurons and glia in sex-, cell- and disease stage-specific manners. Analysis of mitochondrial omics data highlights the involvement of mitochondria in AD, providing a rationale for further disease modeling and drug targeting.
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Affiliation(s)
- Alejandro Marmolejo-Garza
- Department of Molecular Pharmacology, Faculty of Science and Engineering, Groningen Research Institute of Pharmacy (GRIP), University of Groningen, the Netherlands; Department of Biomedical Sciences of Cells & Systems, Section Molecular Neurobiology, Faculty of Medical Sciences, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Tiago Medeiros-Furquim
- Department of Molecular Pharmacology, Faculty of Science and Engineering, Groningen Research Institute of Pharmacy (GRIP), University of Groningen, the Netherlands; Department of Biomedical Sciences of Cells & Systems, Section Molecular Neurobiology, Faculty of Medical Sciences, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Ramya Rao
- Department of Molecular Pharmacology, Faculty of Science and Engineering, Groningen Research Institute of Pharmacy (GRIP), University of Groningen, the Netherlands
| | - Bart J L Eggen
- Department of Biomedical Sciences of Cells & Systems, Section Molecular Neurobiology, Faculty of Medical Sciences, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Erik Boddeke
- Department of Biomedical Sciences of Cells & Systems, Section Molecular Neurobiology, Faculty of Medical Sciences, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands; Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen N, Denmark.
| | - Amalia M Dolga
- Department of Molecular Pharmacology, Faculty of Science and Engineering, Groningen Research Institute of Pharmacy (GRIP), University of Groningen, the Netherlands.
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14
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Zhan B, Shen J. Mitochondria and their potential role in acute lung injury (Review). Exp Ther Med 2022; 24:479. [PMID: 35761815 PMCID: PMC9214601 DOI: 10.3892/etm.2022.11406] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 05/16/2022] [Indexed: 11/06/2022] Open
Affiliation(s)
- Biao Zhan
- Center of Emergency and Critical Medicine, Jinshan Hospital of Fudan University, Shanghai 201508, P.R. China
| | - Jie Shen
- Center of Emergency and Critical Medicine, Jinshan Hospital of Fudan University, Shanghai 201508, P.R. China
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15
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Zhu Z, Hou Q, Wang B, Li C, Liu L, Gong W, Chai J, Guo H. A novel mitochondria-related gene signature for controlling colon cancer cell mitochondrial respiration and proliferation. Hum Cell 2022; 35:1126-1139. [DOI: 10.1007/s13577-022-00702-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 04/05/2022] [Indexed: 01/05/2023]
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16
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Mitochondrial Neurodegeneration. Cells 2022; 11:cells11040637. [PMID: 35203288 PMCID: PMC8870525 DOI: 10.3390/cells11040637] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 01/28/2022] [Accepted: 02/06/2022] [Indexed: 01/27/2023] Open
Abstract
Mitochondria are cytoplasmic organelles, which generate energy as heat and ATP, the universal energy currency of the cell. This process is carried out by coupling electron stripping through oxidation of nutrient substrates with the formation of a proton-based electrochemical gradient across the inner mitochondrial membrane. Controlled dissipation of the gradient can lead to production of heat as well as ATP, via ADP phosphorylation. This process is known as oxidative phosphorylation, and is carried out by four multiheteromeric complexes (from I to IV) of the mitochondrial respiratory chain, carrying out the electron flow whose energy is stored as a proton-based electrochemical gradient. This gradient sustains a second reaction, operated by the mitochondrial ATP synthase, or complex V, which condensates ADP and Pi into ATP. Four complexes (CI, CIII, CIV, and CV) are composed of proteins encoded by genes present in two separate compartments: the nuclear genome and a small circular DNA found in mitochondria themselves, and are termed mitochondrial DNA (mtDNA). Mutations striking either genome can lead to mitochondrial impairment, determining infantile, childhood or adult neurodegeneration. Mitochondrial disorders are complex neurological syndromes, and are often part of a multisystem disorder. In this paper, we divide the diseases into those caused by mtDNA defects and those that are due to mutations involving nuclear genes; from a clinical point of view, we discuss pediatric disorders in comparison to juvenile or adult-onset conditions. The complementary genetic contributions controlling organellar function and the complexity of the biochemical pathways present in the mitochondria justify the extreme genetic and phenotypic heterogeneity of this new area of inborn errors of metabolism known as ‘mitochondrial medicine’.
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17
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Molecular Genetics Overview of Primary Mitochondrial Myopathies. J Clin Med 2022; 11:jcm11030632. [PMID: 35160083 PMCID: PMC8836969 DOI: 10.3390/jcm11030632] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 01/13/2022] [Accepted: 01/20/2022] [Indexed: 12/29/2022] Open
Abstract
Mitochondrial disorders are the most common inherited conditions, characterized by defects in oxidative phosphorylation and caused by mutations in nuclear or mitochondrial genes. Due to its high energy request, skeletal muscle is typically involved. According to the International Workshop of Experts in Mitochondrial Diseases held in Rome in 2016, the term Primary Mitochondrial Myopathy (PMM) should refer to those mitochondrial disorders affecting principally, but not exclusively, the skeletal muscle. The clinical presentation may include general isolated myopathy with muscle weakness, exercise intolerance, chronic ophthalmoplegia/ophthalmoparesis (cPEO) and eyelids ptosis, or multisystem conditions where there is a coexistence with extramuscular signs and symptoms. In recent years, new therapeutic targets have been identified leading to the launch of some promising clinical trials that have mainly focused on treating muscle symptoms and that require populations with defined genotype. Advantages in next-generation sequencing techniques have substantially improved diagnosis. So far, an increasing number of mutations have been identified as responsible for mitochondrial disorders. In this review, we focused on the principal molecular genetic alterations in PMM. Accordingly, we carried out a comprehensive review of the literature and briefly discussed the possible approaches which could guide the clinician to a genetic diagnosis.
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18
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Implication of Adult Hippocampal Neurogenesis in Alzheimer’s Disease and Potential Therapeutic Approaches. Cells 2022; 11:cells11020286. [PMID: 35053402 PMCID: PMC8773637 DOI: 10.3390/cells11020286] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 01/11/2022] [Accepted: 01/12/2022] [Indexed: 12/31/2022] Open
Abstract
Alzheimer’s disease is the most common neurodegenerative disease, affecting more than 6 million US citizens and representing the most prevalent cause for dementia. Neurogenesis has been repeatedly reported to be impaired in AD mouse models, but the reason for this impairment remains unclear. Several key factors play a crucial role in AD including Aβ accumulation, intracellular neurofibrillary tangles accumulation, and neuronal loss (specifically in the dentate gyrus of the hippocampus). Neurofibrillary tangles have been long associated with the neuronal loss in the dentate gyrus. Of note, Aβ accumulation plays an important role in the impairment of neurogenesis, but recent studies started to shed a light on the role of APP gene expression on the neurogenesis process. In this review, we will discuss the recent approaches to neurogenesis in Alzheimer disease and update the development of therapeutic methods.
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19
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Fan W, Jin X, Xu M, Xi Y, Lu W, Yang X, Guan MX, Ge W. FARS2 deficiency in Drosophila reveals the developmental delay and seizure manifested by aberrant mitochondrial tRNA metabolism. Nucleic Acids Res 2021; 49:13108-13121. [PMID: 34878141 PMCID: PMC8682739 DOI: 10.1093/nar/gkab1187] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 11/08/2021] [Accepted: 11/17/2021] [Indexed: 01/16/2023] Open
Abstract
Mutations in genes encoding mitochondrial aminoacyl-tRNA synthetases are linked to diverse diseases. However, the precise mechanisms by which these mutations affect mitochondrial function and disease development are not fully understood. Here, we develop a Drosophila model to study the function of dFARS2, the Drosophila homologue of the mitochondrial phenylalanyl–tRNA synthetase, and further characterize human disease-associated FARS2 variants. Inactivation of dFARS2 in Drosophila leads to developmental delay and seizure. Biochemical studies reveal that dFARS2 is required for mitochondrial tRNA aminoacylation, mitochondrial protein stability, and assembly and enzyme activities of OXPHOS complexes. Interestingly, by modeling FARS2 mutations associated with human disease in Drosophila, we provide evidence that expression of two human FARS2 variants, p.G309S and p.D142Y, induces seizure behaviors and locomotion defects, respectively. Together, our results not only show the relationship between dysfunction of mitochondrial aminoacylation system and pathologies, but also illustrate the application of Drosophila model for functional analysis of human disease-causing variants.
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Affiliation(s)
- Wenlu Fan
- Division of Human Reproduction and Developmental Genetics, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China.,Institute of Genetics, Zhejiang University, 866 Yuhangtang Road, Hangzhou, Zhejiang 310058, China.,Zhejiang Provincial Key Laboratory of Precision Diagnosis and Therapy for Major Gynecological Diseases, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310006, China
| | - Xiaoye Jin
- Division of Human Reproduction and Developmental Genetics, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China.,Institute of Genetics, Zhejiang University, 866 Yuhangtang Road, Hangzhou, Zhejiang 310058, China.,Zhejiang Provincial Key Laboratory of Precision Diagnosis and Therapy for Major Gynecological Diseases, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310006, China
| | - Man Xu
- Division of Human Reproduction and Developmental Genetics, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China.,Institute of Genetics, Zhejiang University, 866 Yuhangtang Road, Hangzhou, Zhejiang 310058, China.,Zhejiang Provincial Key Laboratory of Precision Diagnosis and Therapy for Major Gynecological Diseases, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310006, China
| | - Yongmei Xi
- Division of Human Reproduction and Developmental Genetics, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China.,Institute of Genetics, Zhejiang University, 866 Yuhangtang Road, Hangzhou, Zhejiang 310058, China
| | - Weiguo Lu
- Department of Gynecologic Oncology, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310006, China.,Cancer Center, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Xiaohang Yang
- Division of Human Reproduction and Developmental Genetics, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China.,Institute of Genetics, Zhejiang University, 866 Yuhangtang Road, Hangzhou, Zhejiang 310058, China.,Zhejiang Provincial Key Laboratory of Genetic and Developmental Disorders, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Min-Xin Guan
- Institute of Genetics, Zhejiang University, 866 Yuhangtang Road, Hangzhou, Zhejiang 310058, China.,Zhejiang Provincial Key Laboratory of Genetic and Developmental Disorders, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Wanzhong Ge
- Division of Human Reproduction and Developmental Genetics, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China.,Institute of Genetics, Zhejiang University, 866 Yuhangtang Road, Hangzhou, Zhejiang 310058, China.,Zhejiang Provincial Key Laboratory of Precision Diagnosis and Therapy for Major Gynecological Diseases, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310006, China.,Cancer Center, Zhejiang University, Hangzhou, Zhejiang 310058, China
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20
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Ohkubo A, Van Haute L, Rudler DL, Stentenbach M, Steiner FA, Rackham O, Minczuk M, Filipovska A, Martinou JC. The FASTK family proteins fine-tune mitochondrial RNA processing. PLoS Genet 2021; 17:e1009873. [PMID: 34748562 PMCID: PMC8601606 DOI: 10.1371/journal.pgen.1009873] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 11/18/2021] [Accepted: 10/11/2021] [Indexed: 12/28/2022] Open
Abstract
Transcription of the human mitochondrial genome and correct processing of the two long polycistronic transcripts are crucial for oxidative phosphorylation. According to the tRNA punctuation model, nucleolytic processing of these large precursor transcripts occurs mainly through the excision of the tRNAs that flank most rRNAs and mRNAs. However, some mRNAs are not punctuated by tRNAs, and it remains largely unknown how these non-canonical junctions are resolved. The FASTK family proteins are emerging as key players in non-canonical RNA processing. Here, we have generated human cell lines carrying single or combined knockouts of several FASTK family members to investigate their roles in non-canonical RNA processing. The most striking phenotypes were obtained with loss of FASTKD4 and FASTKD5 and with their combined double knockout. Comprehensive mitochondrial transcriptome analyses of these cell lines revealed a defect in processing at several canonical and non-canonical RNA junctions, accompanied by an increase in specific antisense transcripts. Loss of FASTKD5 led to the most severe phenotype with marked defects in mitochondrial translation of key components of the electron transport chain complexes and in oxidative phosphorylation. We reveal that the FASTK protein family members are crucial regulators of non-canonical junction and non-coding mitochondrial RNA processing. As a legacy of their bacterial origin, mitochondria have retained their own genome with a unique gene expression system. All mitochondrially encoded proteins are essential components of the respiratory chain. Therefore, the mitochondrial gene expression is crucial for their iconic role as the ‘powerhouse of the cell’–ATP synthesis through oxidative phosphorylation. Consistently, defects in enzymes involved in this gene expression system are a common source of incurable inherited metabolic disorders, called mitochondrial diseases. The human mitochondrial transcription generates long polycistronic transcripts that carry information for multiple genes, so that the expression level of each gene is mainly regulated through post-transcriptional events. The polycistronic transcript first undergoes RNA processing, where individual mRNA, rRNA, and tRNA are cleaved off. However, its entire molecular mechanism remains unclear, and in particular, ‘non-canonical’ RNA processing has been poorly understood. To address this question, we studied the FASTK family proteins, emerging key mitochondrial post-transcriptional regulators. We generated different human cell lines carrying single or combined disruption of FASTKD3, FASTKD4, and FASTKD5 genes, and analyzed them using biochemical and genetic approaches. We show that the FASTK family members fine-tune the processing of both ‘canonical’ and ‘non-canonical’ mitochondrial RNA junctions.
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Affiliation(s)
- Akira Ohkubo
- Department of Cell Biology, University of Geneva, Geneva, Switzerland
| | - Lindsey Van Haute
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge, United Kingdom
| | - Danielle L. Rudler
- Harry Perkins Institute of Medical Research, Queen Elizabeth II Medical Centre, Perth, Australia
- ARC Centre of Excellence in Synthetic Biology, Queen Elizabeth II Medical Centre, Perth, Australia
- Centre for Medical Research, The University of Western Australia, Queen Elizabeth II Medical Centre, Perth, Australia
| | - Maike Stentenbach
- Harry Perkins Institute of Medical Research, Queen Elizabeth II Medical Centre, Perth, Australia
- ARC Centre of Excellence in Synthetic Biology, Queen Elizabeth II Medical Centre, Perth, Australia
- Centre for Medical Research, The University of Western Australia, Queen Elizabeth II Medical Centre, Perth, Australia
| | - Florian A. Steiner
- Department of Molecular Biology, University of Geneva, Geneva, Switzerland
| | - Oliver Rackham
- Harry Perkins Institute of Medical Research, Queen Elizabeth II Medical Centre, Perth, Australia
- ARC Centre of Excellence in Synthetic Biology, Queen Elizabeth II Medical Centre, Perth, Australia
- School of Pharmacy and Biomedical Sciences, Curtin University, Perth, Australia
- Curtin Health Innovation Research Institute, Curtin University, Perth, Australia
- Telethon Kids Institute, Perth Children’s Hospital, Perth, Australia
| | - Michal Minczuk
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge, United Kingdom
| | - Aleksandra Filipovska
- Harry Perkins Institute of Medical Research, Queen Elizabeth II Medical Centre, Perth, Australia
- ARC Centre of Excellence in Synthetic Biology, Queen Elizabeth II Medical Centre, Perth, Australia
- Centre for Medical Research, The University of Western Australia, Queen Elizabeth II Medical Centre, Perth, Australia
- Telethon Kids Institute, Perth Children’s Hospital, Perth, Australia
- School of Molecular Sciences, The University of Western Australia, Perth, Australia
- * E-mail: (AF); (J-CM)
| | - Jean-Claude Martinou
- Department of Cell Biology, University of Geneva, Geneva, Switzerland
- * E-mail: (AF); (J-CM)
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21
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Olimpio C, Tiet MY, Horvath R. Primary mitochondrial myopathies in childhood. Neuromuscul Disord 2021; 31:978-987. [PMID: 34736635 DOI: 10.1016/j.nmd.2021.08.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 07/29/2021] [Accepted: 08/05/2021] [Indexed: 12/30/2022]
Abstract
Primary mitochondrial myopathies are genetic metabolic disorders of mitochondrial dysfunction affecting mainly, but not exclusively, skeletal muscle. Although individually rare, they are the most common inherited metabolic disorders in childhood. They can be similar to other childhood muscle diseases such as congenital myopathies, dystrophies, myasthenic syndromes or metabolic myopathies and a muscle biopsy and genetic testing are important in the differential diagnosis. Mitochondrial myopathies can present at any age but typically childhood onset myopathies have more significant muscle involvement and are caused by genes encoded in the nuclear DNA. Mitochondrial myopathy in infants presents with hypotonia, muscle weakness and difficulty feeding. In toddlers and older children delayed motor development, exercise intolerance and premature fatigue are common. A number of nuclear DNA and mitochondrial DNA encoded genes are known to cause isolated myopathy in childhood and they are important in a range of mitochondrial functions such as oxidative phosphorylation, mitochondrial transcription/translation and mitochondrial fusion/fission. A rare cause of isolated myopathy in children, reversible infantile respiratory chain deficiency myopathy, is non-progressive and typically associated with spontaneous full recovery. Promising targeted treatments have been reported for a number or mitochondrial myopathies including riboflavin in ACAD9 and ETFDH-myopathies and deoxynucleoside for TK2-related disease.
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Affiliation(s)
- Catarina Olimpio
- East Anglian Medical Genetics Service, Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom
| | - May Yung Tiet
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
| | - Rita Horvath
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom.
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22
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Zheng WQ, Pedersen SV, Thompson K, Bellacchio E, French CE, Munro B, Pearson TS, Vogt J, Diodato D, Diemer T, Ernst A, Horvath R, Chitre M, Ek J, Wibrand F, Grange DK, Raymond L, Zhou XL, Taylor RW, Ostergaard E. Elucidating the molecular mechanisms associated with TARS2-related mitochondrial disease. Hum Mol Genet 2021; 31:523-534. [PMID: 34508595 DOI: 10.1093/hmg/ddab257] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 08/30/2021] [Accepted: 08/31/2021] [Indexed: 11/12/2022] Open
Abstract
TARS2 encodes human mitochondrial threonyl tRNA-synthetase that is responsible for generating mitochondrial Thr-tRNAThr and clearing mischarged Ser-tRNAThr during mitochondrial translation. Pathogenic variants in TARS2 have hitherto been reported in a pair of siblings and an unrelated patient with an early onset mitochondrial encephalomyopathy and a combined respiratory chain enzyme deficiency in muscle. We here report five additional unrelated patients with TARS2-related mitochondrial diseases, expanding the clinical phenotype to also include epilepsy, dystonia, hyperhidrosis and severe hearing impairment. Additionally, we document seven novel TARS2 variants-one nonsense variant and six missense variants-that we demonstrate are pathogenic and causal of the disease presentation based on population frequency, homology modelling and functional studies that show the effects of the pathogenic variants on TARS2 stability and/or function.
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Affiliation(s)
- Wen-Qiang Zheng
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, 200031, China.,School of Life Science and Technology, ShanghaiTech University, 393 Middle Hua Xia Road, Shanghai 201210, China
| | - Signe Vandal Pedersen
- Department of Clinical Genetics, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Kyle Thompson
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK
| | - Emanuele Bellacchio
- Area di Ricerca Genetica e Malattie Rare, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Courtney E French
- Department of Medical Genetics, University of Cambridge, Cambridge, UK
| | - Benjamin Munro
- Department of Clinical Neurosciences, John Van Geest Centre for Brain Repair, School of Clinical Medicine, University of Cambridge, Cambridge, UK
| | - Toni S Pearson
- Department of Neurology, Washington University School of Medicine, St. Louis, MO, USA
| | - Julie Vogt
- West Midlands Regional Genetics Service, Birmingham Women's and Children's NHS Foundation Trust, Birmingham Women's Hospital, Birmingham, UK
| | - Daria Diodato
- Neuromuscular and Neurodegenerative Disease Unit, Children Hospital Bambino Gesù, Rome, Italy
| | - Tue Diemer
- Department of Clinical Genetics, Aalborg University Hospital, Aalborg, Denmark
| | - Anja Ernst
- Department of Molecular Diagnostics, Aalborg University Hospital, Aalborg, Denmark
| | - Rita Horvath
- Department of Clinical Neurosciences, John Van Geest Centre for Brain Repair, School of Clinical Medicine, University of Cambridge, Cambridge, UK
| | - Manali Chitre
- Department of Paediatric Neurology, Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom
| | - Jakob Ek
- Department of Clinical Genetics, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Flemming Wibrand
- Department of Clinical Genetics, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Dorothy K Grange
- Department of Pediatrics, Division Genetics and Genomic Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Lucy Raymond
- Department of Medical Genetics, University of Cambridge, Cambridge, UK
| | - Xiao-Long Zhou
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, 200031, China
| | - Robert W Taylor
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK
| | - Elsebet Ostergaard
- Department of Clinical Genetics, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark.,Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
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23
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Zanfardino P, Doccini S, Santorelli FM, Petruzzella V. Tackling Dysfunction of Mitochondrial Bioenergetics in the Brain. Int J Mol Sci 2021; 22:8325. [PMID: 34361091 PMCID: PMC8348117 DOI: 10.3390/ijms22158325] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 07/29/2021] [Accepted: 07/30/2021] [Indexed: 12/15/2022] Open
Abstract
Oxidative phosphorylation (OxPhos) is the basic function of mitochondria, although the landscape of mitochondrial functions is continuously growing to include more aspects of cellular homeostasis. Thanks to the application of -omics technologies to the study of the OxPhos system, novel features emerge from the cataloging of novel proteins as mitochondrial thus adding details to the mitochondrial proteome and defining novel metabolic cellular interrelations, especially in the human brain. We focussed on the diversity of bioenergetics demand and different aspects of mitochondrial structure, functions, and dysfunction in the brain. Definition such as 'mitoexome', 'mitoproteome' and 'mitointeractome' have entered the field of 'mitochondrial medicine'. In this context, we reviewed several genetic defects that hamper the last step of aerobic metabolism, mostly involving the nervous tissue as one of the most prominent energy-dependent tissues and, as consequence, as a primary target of mitochondrial dysfunction. The dual genetic origin of the OxPhos complexes is one of the reasons for the complexity of the genotype-phenotype correlation when facing human diseases associated with mitochondrial defects. Such complexity clinically manifests with extremely heterogeneous symptoms, ranging from organ-specific to multisystemic dysfunction with different clinical courses. Finally, we briefly discuss the future directions of the multi-omics study of human brain disorders.
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Affiliation(s)
- Paola Zanfardino
- Department of Medical Basic Sciences, Neurosciences and Sense Organs, University of Bari Aldo Moro, 70124 Bari, Italy;
| | - Stefano Doccini
- IRCCS Fondazione Stella Maris, Calambrone, 56128 Pisa, Italy;
| | | | - Vittoria Petruzzella
- Department of Medical Basic Sciences, Neurosciences and Sense Organs, University of Bari Aldo Moro, 70124 Bari, Italy;
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24
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Friederich MW, Geddes GC, Wortmann SB, Punnoose A, Wartchow E, Knight KM, Prokisch H, Creadon-Swindell G, Mayr JA, Van Hove JLK. Pathogenic variants in MRPL44 cause infantile cardiomyopathy due to a mitochondrial translation defect. Mol Genet Metab 2021; 133:362-371. [PMID: 34140213 PMCID: PMC8289749 DOI: 10.1016/j.ymgme.2021.06.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 06/03/2021] [Accepted: 06/04/2021] [Indexed: 11/22/2022]
Abstract
Cardiac dysfunction is a common phenotypic manifestation of primary mitochondrial disease with multiple nuclear and mitochondrial DNA pathogenic variants as a cause, including disorders of mitochondrial translation. To date, five patients have been described with pathogenic variants in MRPL44, encoding the ml44 protein which is part of the large subunit of the mitochondrial ribosome (mitoribosome). Three presented as infants with hypertrophic cardiomyopathy, mild lactic acidosis, and easy fatigue and muscle weakness, whereas two presented in adolescence with myopathy and neurological symptoms. We describe two infants who presented with cardiomyopathy from the neonatal period, failure to thrive, hypoglycemia and in one infant lactic acidosis. A decompensation of the cardiac function in the first year resulted in demise. Exome sequencing identified compound heterozygous variants in the MRPL44 gene including the known pathogenic variant c.467 T > G and two novel pathogenic variants. We document a combined respiratory chain enzyme deficiency with emphasis on complex I and IV, affecting heart muscle tissue more than skeletal muscle or fibroblasts. We show this to be caused by reduced mitochondrial DNA encoded protein synthesis affecting all subunits, and resulting in dysfunction of complex I and IV assembly. The degree of oxidative phosphorylation dysfunction correlated with the impairment of mitochondrial protein synthesis due to different pathogenic variants. These functional studies allow for improved understanding of the pathogenesis of MRPL44-associated mitochondrial disorder.
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Affiliation(s)
- Marisa W Friederich
- Department of Pediatrics, Section of Clinical Genetics and Metabolism, University of Colorado, Aurora, CO, USA; Department of Pathology and Laboratory Services, Children's Hospital Colorado, Aurora, CO, USA
| | - Gabrielle C Geddes
- Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI, USA; Department of Molecular and Medical Genetics, Indiana University, Indianapolis, IN, USA
| | - Saskia B Wortmann
- University Children's Hospital, Paracelsus Medical University (PMU), Salzburg, Austria; Amalia Children's Hospital, RadboudUMC, Nijmegen, the Netherlands
| | - Ann Punnoose
- Herma Heart Institute, Children's Hospital of Wisconsin, Milwaukee, WI, USA
| | - Eric Wartchow
- Department of Pathology and Laboratory Services, Children's Hospital Colorado, Aurora, CO, USA
| | - Kaz M Knight
- Department of Pediatrics, Section of Clinical Genetics and Metabolism, University of Colorado, Aurora, CO, USA
| | - Holger Prokisch
- Institute of Neurogenomics, Helmholtz Zentrum München, Neuherberg, Germany; Institute of Human Genetics, Technical University of Munich, Munich, Germany
| | | | - Johannes A Mayr
- University Children's Hospital, Paracelsus Medical University (PMU), Salzburg, Austria
| | - Johan L K Van Hove
- Department of Pediatrics, Section of Clinical Genetics and Metabolism, University of Colorado, Aurora, CO, USA; Department of Pathology and Laboratory Services, Children's Hospital Colorado, Aurora, CO, USA.
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25
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D’Souza AR, Van Haute L, Powell CA, Mutti CD, Páleníková P, Rebelo-Guiomar P, Rorbach J, Minczuk M. YbeY is required for ribosome small subunit assembly and tRNA processing in human mitochondria. Nucleic Acids Res 2021; 49:5798-5812. [PMID: 34037799 PMCID: PMC8191802 DOI: 10.1093/nar/gkab404] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 04/20/2021] [Accepted: 05/06/2021] [Indexed: 12/12/2022] Open
Abstract
Mitochondria contain their own translation apparatus which enables them to produce the polypeptides encoded in their genome. The mitochondrially-encoded RNA components of the mitochondrial ribosome require various post-transcriptional processing steps. Additional protein factors are required to facilitate the biogenesis of the functional mitoribosome. We have characterized a mitochondrially-localized protein, YbeY, which interacts with the assembling mitoribosome through the small subunit. Loss of YbeY leads to a severe reduction in mitochondrial translation and a loss of cell viability, associated with less accurate mitochondrial tRNASer(AGY) processing from the primary transcript and a defect in the maturation of the mitoribosomal small subunit. Our results suggest that YbeY performs a dual, likely independent, function in mitochondria being involved in precursor RNA processing and mitoribosome biogenesis. Issue Section: Nucleic Acid Enzymes.
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Affiliation(s)
- Aaron R D’Souza
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Hills Road, Cambridge CB2 0XY, UK
| | - Lindsey Van Haute
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Hills Road, Cambridge CB2 0XY, UK
| | - Christopher A Powell
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Hills Road, Cambridge CB2 0XY, UK
| | - Christian D Mutti
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Hills Road, Cambridge CB2 0XY, UK
| | - Petra Páleníková
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Hills Road, Cambridge CB2 0XY, UK
| | - Pedro Rebelo-Guiomar
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Hills Road, Cambridge CB2 0XY, UK
| | - Joanna Rorbach
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Hills Road, Cambridge CB2 0XY, UK
| | - Michal Minczuk
- To whom correspondence should be addressed. Tel: +44 122 325 2750;
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26
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Alam J, Rahman FT, Sah-Teli SK, Venkatesan R, Koski MK, Autio KJ, Hiltunen JK, Kastaniotis AJ. Expression and analysis of the SAM-dependent RNA methyltransferase Rsm22 from Saccharomyces cerevisiae. Acta Crystallogr D Struct Biol 2021; 77:840-853. [PMID: 34076597 PMCID: PMC8171064 DOI: 10.1107/s2059798321004149] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 04/17/2021] [Indexed: 12/04/2022] Open
Abstract
Rsm22-family proteins are conserved putative SAM-dependent methyltransferases with important functions in mitochondrial translation. Here, the results of a comparative bioinformatics analysis of Rsm22-type proteins are presented, the expression, biophysical characterization and crystallization of Saccharomyces cerevisiae Rsm22 are reported, a low-resolution SAXS structure of the protein is revealed, and SAM-dependent RNA methyl transferase activity of the protein is demonstrated. The Saccharomyces cerevisiae Rsm22 protein (Sc-Rsm22), encoded by the nuclear RSM22 (systematic name YKL155c) gene, is a distant homologue of Rsm22 from Trypanosoma brucei (Tb-Rsm22) and METTL17 from mouse (Mm-METTL17). All three proteins have been shown to be associated with mitochondrial gene expression, and Sc-Rsm22 has been documented to be essential for mitochondrial respiration. The Sc-Rsm22 protein comprises a polypeptide of molecular weight 72.2 kDa that is predicted to harbor an N-terminal mitochondrial targeting sequence. The precise physiological function of Rsm22-family proteins is unknown, and no structural information has been available for Sc-Rsm22 to date. In this study, Sc-Rsm22 was expressed and purified in monomeric and dimeric forms, their folding was confirmed by circular-dichroism analyses and their low-resolution structures were determined using a small-angle X-ray scattering (SAXS) approach. The solution structure of the monomeric form of Sc-Rsm22 revealed an elongated three-domain arrangement, which differs from the shape of Tb-Rsm22 in its complex with the mitochondrial small ribosomal subunit in T. brucei (PDB entry 6sg9). A bioinformatic analysis revealed that the core domain in the middle (Leu117–Asp462 in Sc-Rsm22) resembles the corresponding region in Tb-Rsm22, including a Rossmann-like methyltransferase fold followed by a zinc-finger-like structure. The latter structure is not present in this position in other methyltransferases and is therefore a unique structural motif for this family. The first half of the C-terminal domain is likely to form an OB-fold, which is typically found in RNA-binding proteins and is also seen in the Tb-Rsm22 structure. In contrast, the N-terminal domain of Sc-Rsm22 is predicted to be fully α-helical and shares no sequence similarity with other family members. Functional studies demonstrated that the monomeric variant of Sc-Rsm22 methylates mitochondrial tRNAs in vitro. These data suggest that Sc-Rsm22 is a new and unique member of the RNA methyltransferases that is important for mitochondrial protein synthesis.
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Affiliation(s)
- Jahangir Alam
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Aapistie 7B, FIN-90220 Oulu, Finland
| | - Farah Tazkera Rahman
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Aapistie 7B, FIN-90220 Oulu, Finland
| | - Shiv K Sah-Teli
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Aapistie 7B, FIN-90220 Oulu, Finland
| | - Rajaram Venkatesan
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Aapistie 7B, FIN-90220 Oulu, Finland
| | | | - Kaija J Autio
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Aapistie 7B, FIN-90220 Oulu, Finland
| | - J Kalervo Hiltunen
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Aapistie 7B, FIN-90220 Oulu, Finland
| | - Alexander J Kastaniotis
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Aapistie 7B, FIN-90220 Oulu, Finland
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27
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Jang YH, Ahn SR, Shim JY, Lim KI. Engineering Genetic Systems for Treating Mitochondrial Diseases. Pharmaceutics 2021; 13:810. [PMID: 34071708 PMCID: PMC8227772 DOI: 10.3390/pharmaceutics13060810] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 05/23/2021] [Accepted: 05/24/2021] [Indexed: 12/13/2022] Open
Abstract
Mitochondria are intracellular energy generators involved in various cellular processes. Therefore, mitochondrial dysfunction often leads to multiple serious diseases, including neurodegenerative and cardiovascular diseases. A better understanding of the underlying mitochondrial dysfunctions of the molecular mechanism will provide important hints on how to mitigate the symptoms of mitochondrial diseases and eventually cure them. In this review, we first summarize the key parts of the genetic processes that control the physiology and functions of mitochondria and discuss how alterations of the processes cause mitochondrial diseases. We then list up the relevant core genetic components involved in these processes and explore the mutations of the components that link to the diseases. Lastly, we discuss recent attempts to apply multiple genetic methods to alleviate and further reverse the adverse effects of the core component mutations on the physiology and functions of mitochondria.
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Affiliation(s)
- Yoon-ha Jang
- Department of Chemical and Biological Engineering, Sookmyung Women’s University, Yongsan-gu, Seoul 04310, Korea; (Y.-h.J.); (J.-y.S.)
| | - Sae Ryun Ahn
- Industry Collaboration Center, Industry-Academic Cooperation Foundation, Sookmyung Women’s University, Yongsan-gu, Seoul 04310, Korea;
| | - Ji-yeon Shim
- Department of Chemical and Biological Engineering, Sookmyung Women’s University, Yongsan-gu, Seoul 04310, Korea; (Y.-h.J.); (J.-y.S.)
| | - Kwang-il Lim
- Department of Chemical and Biological Engineering, Sookmyung Women’s University, Yongsan-gu, Seoul 04310, Korea; (Y.-h.J.); (J.-y.S.)
- Industry Collaboration Center, Industry-Academic Cooperation Foundation, Sookmyung Women’s University, Yongsan-gu, Seoul 04310, Korea;
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28
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Macken WL, Vandrovcova J, Hanna MG, Pitceathly RDS. Applying genomic and transcriptomic advances to mitochondrial medicine. Nat Rev Neurol 2021; 17:215-230. [PMID: 33623159 DOI: 10.1038/s41582-021-00455-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/06/2021] [Indexed: 02/07/2023]
Abstract
Next-generation sequencing (NGS) has increased our understanding of the molecular basis of many primary mitochondrial diseases (PMDs). Despite this progress, many patients with suspected PMD remain without a genetic diagnosis, which restricts their access to in-depth genetic counselling, reproductive options and clinical trials, in addition to hampering efforts to understand the underlying disease mechanisms. Although they represent a considerable improvement over their predecessors, current methods for sequencing the mitochondrial and nuclear genomes have important limitations, and molecular diagnostic techniques are often manual and time consuming. However, recent advances in genomics and transcriptomics offer realistic solutions to these challenges. In this Review, we discuss the current genetic testing approach for PMDs and the opportunities that exist for increased use of whole-genome NGS of nuclear and mitochondrial DNA (mtDNA) in the clinical environment. We consider the possible role for long-read approaches in sequencing of mtDNA and in the identification of novel nuclear genomic causes of PMDs. We examine the expanding applications of RNA sequencing, including the detection of cryptic variants that affect splicing and gene expression and the interpretation of rare and novel mitochondrial transfer RNA variants.
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Affiliation(s)
- William L Macken
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, UK
| | - Jana Vandrovcova
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, UK
| | - Michael G Hanna
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, UK
| | - Robert D S Pitceathly
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, UK.
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29
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Oktay Y, Güngör S, Zeltner L, Wiethoff S, Schöls L, Sonmezler E, Yilmaz E, Munro B, Bender B, Kernstock C, Kaemereit S, Liepelt I, Töpf A, Yis U, Laurie S, Yaramis A, Zuchner S, Hiz S, Lochmüller H, Schüle R, Horvath R. Confirmation of TACO1 as a Leigh Syndrome Disease Gene in Two Additional Families. J Neuromuscul Dis 2021; 7:301-308. [PMID: 32444556 PMCID: PMC7458500 DOI: 10.3233/jnd-200510] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Background: In 2009, we identified TACO1 as a novel mitochondrial disease gene in a single family, however no second family has been described to confirm the role of TACO1 in mitochondrial disease. Objective: In this report, we describe two independent consanguineous families carrying pathogenic variants in TACO1, confirming the phenotype. Methods: Detailed clinical investigations and whole exome sequencing with haplotype analysis have been performed in several members of the two reported families. Results: Clinical phenotype of the patients confirms the originally reported phenotype of a childhood-onset progressive cerebellar and pyramidal syndrome with optic atrophy and learning difficulties. Brain MRI showed periventricular white matter lesions with multiple cystic defects, suggesting leukoencephalopathy in both patients. One patient carried the previously described homozygous TACO1 variant (p.His158ProfsTer8) and haplotype analysis suggested that this variant is a rare founder mutation. The second patient from another family carried a homozygous novel frame shift variant (p.Cys85PhefsTer15). Conclusions: The identification of two Turkish families with similar characteristic clinical presentation and an additional homozygous nonsense mutation confirms that TACO1 is a human mitochondrial disease gene. Although most patients with this clinical presentation undergo next generation sequencing analysis, screening for selected founder mutations in the Turkish population based on the precise clinical presentation may reduce time and cost of finding the genetic diagnosis even in the era of massively parallel sequencing.
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Affiliation(s)
- Yavuz Oktay
- Izmir Biomedicine and Genome Center, Dokuz Eylul University Health Campus, Izmir, Turkey.,Izmir International Biomedicine and Genome Institute, Dokuz Eylul University, Izmir, Turkey
| | - Serdal Güngör
- Inonu University, Faculty of Medicine, Turgut Ozal Research Center, Department of Paediatric Neurology, Malatya, Turkey
| | - Lena Zeltner
- Department of Neurodegenerative Diseases, Hertie-Institute for Clinical Brain Research and Center of Neurology, University of Tübingen, Tübingen, Germany
| | - Sarah Wiethoff
- Department of Neurodegenerative Diseases, Hertie-Institute for Clinical Brain Research and Center of Neurology, University of Tübingen, Tübingen, Germany
| | - Ludger Schöls
- Department of Neurodegenerative Diseases, Hertie-Institute for Clinical Brain Research and Center of Neurology, University of Tübingen, Tübingen, Germany.,German Center for Neurodegenerative Diseases (DZNE), University of Tübingen, Tübingen, Germany
| | - Ece Sonmezler
- Izmir Biomedicine and Genome Center, Dokuz Eylul University Health Campus, Izmir, Turkey.,Izmir International Biomedicine and Genome Institute, Dokuz Eylul University, Izmir, Turkey
| | - Elmasnur Yilmaz
- Izmir Biomedicine and Genome Center, Dokuz Eylul University Health Campus, Izmir, Turkey.,Izmir International Biomedicine and Genome Institute, Dokuz Eylul University, Izmir, Turkey
| | - Benjamin Munro
- Department of Clinical Neurosciences, University of Cambridge School of Clinical Medicine, Cambridge Biomedical Campus, Cambridge, UK
| | - Benjamin Bender
- Diagnostic and Interventional Neuroradiology, Radiologic Clinics, University of Tübingen, Tübingen, Germany
| | - Christoph Kernstock
- Centre for Ophthalmology, University Eye Hospital Tübingen, University of Tübingen, Tübingen, Germany
| | - Sofie Kaemereit
- Department of Neurodegenerative Diseases, Hertie-Institute for Clinical Brain Research and Center of Neurology, University of Tübingen, Tübingen, Germany
| | - Inga Liepelt
- Department of Neurodegenerative Diseases, Hertie-Institute for Clinical Brain Research and Center of Neurology, University of Tübingen, Tübingen, Germany.,German Center for Neurodegenerative Diseases (DZNE), University of Tübingen, Tübingen, Germany
| | - Ana Töpf
- John Waltom Muscular Dystrophy Research Centre, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK
| | - Uluc Yis
- Dokuz Eylul University, School of Medicine, Department of Paediatric Neurology, Izmir, Turkey
| | - Steven Laurie
- CNAG-CRG, Centre for Genomic Regulation, Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Ahmet Yaramis
- Pediatric Neurology Clinic, Private Office, Diyarbakir, Turkey
| | - Stephan Zuchner
- Department of Human Genetics and Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Semra Hiz
- Izmir Biomedicine and Genome Center, Dokuz Eylul University Health Campus, Izmir, Turkey.,Dokuz Eylul University, School of Medicine, Department of Paediatric Neurology, Izmir, Turkey
| | - Hanns Lochmüller
- CNAG-CRG, Centre for Genomic Regulation, Barcelona Institute of Science and Technology, Barcelona, Spain.,Department of Neuropediatrics and Muscle Disorders, Medical Center-University of Freiburg, Faculty of Medicine, Freiburg, Germany.,Children's Hospital of Eastern Ontario Research Institute; Division of Neurology, Department of Medicine, The Ottawa Hospital; and Brain and Mind Research Institute, University of Ottawa, Canada
| | - Rebecca Schüle
- Department of Neurodegenerative Diseases, Hertie-Institute for Clinical Brain Research and Center of Neurology, University of Tübingen, Tübingen, Germany.,German Center for Neurodegenerative Diseases (DZNE), University of Tübingen, Tübingen, Germany
| | - Rita Horvath
- Department of Clinical Neurosciences, University of Cambridge School of Clinical Medicine, Cambridge Biomedical Campus, Cambridge, UK
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30
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Jin X, Zhang Z, Nie Z, Wang C, Meng F, Yi Q, Chen M, Sun J, Zou J, Jiang P, Guan MX. An animal model for mitochondrial tyrosyl-tRNA synthetase deficiency reveals links between oxidative phosphorylation and retinal function. J Biol Chem 2021; 296:100437. [PMID: 33610547 PMCID: PMC8010715 DOI: 10.1016/j.jbc.2021.100437] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 02/09/2021] [Accepted: 02/16/2021] [Indexed: 12/13/2022] Open
Abstract
Mitochondria maintain a distinct pool of ribosomal machinery, including tRNAs and tRNAs activating enzymes, such as mitochondrial tyrosyl-tRNA synthetase (YARS2). Mutations in YARS2, which typically lead to the impairment of mitochondrial protein synthesis, have been linked to an array of human diseases including optic neuropathy. However, the lack of YARS2 mutation animal model makes us difficult to elucidate the pathophysiology underlying YARS2 deficiency. To explore this system, we generated YARS2 knockout (KO) HeLa cells and zebrafish using CRISPR/Cas9 technology. We observed the aberrant tRNATyr aminoacylation overall and reductions in the levels in mitochondrion- and nucleus-encoding subunits of oxidative phosphorylation system (OXPHOS), which were especially pronounced effects in the subunits of complex I and complex IV. These deficiencies manifested the decreased levels of intact supercomplexes overall. Immunoprecipitation assays showed that YARS2 bound to specific subunits of complex I and complex IV, suggesting the posttranslational stabilization of OXPHOS. Furthermore, YARS2 ablation caused defects in the stability and activities of OXPHOS complexes. These biochemical defects could be rescued by the overexpression of YARS2 cDNA in the YARS2KO cells. In zebrafish, the yars2KO larva conferred deficient COX activities in the retina, abnormal mitochondrial morphology, and numbers in the photoreceptor and retinal ganglion cells. The zebrafish further exhibited the retinal defects affecting both rods and cones. Vision defects in yars2KO zebrafish recapitulated the clinical phenotypes in the optic neuropathy patients carrying the YARS2 mutations. Our findings highlighted the critical role of YARS2 in the stability and activity of OXPHOS and its pathological consequence in vision impairments.
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Affiliation(s)
- Xiaofen Jin
- Key Laboratory of Reproductive Genetics, Ministry of Education of PRC, The Woman's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China; Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, and National Clinic Research Center for Child Health, Hangzhou, Zhejiang, China; Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Zengming Zhang
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Zhipeng Nie
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Chenghui Wang
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Feilong Meng
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, and National Clinic Research Center for Child Health, Hangzhou, Zhejiang, China; Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Qiuzi Yi
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Mengquan Chen
- Department of Lab Medicine, Wenzhou Hospital of Traditional Chinese Medicine, Wenzhou, Zhejiang, China
| | - Jiji Sun
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Jian Zou
- Insitute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Pingping Jiang
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, and National Clinic Research Center for Child Health, Hangzhou, Zhejiang, China; Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China; Zhejiang Provincial Key Laboratory of Genetic & Developmental Disorders, Zhejiang Univesity, Hangzhou, Zhejiang, China.
| | - Min-Xin Guan
- Key Laboratory of Reproductive Genetics, Ministry of Education of PRC, The Woman's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China; Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, and National Clinic Research Center for Child Health, Hangzhou, Zhejiang, China; Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China; Zhejiang Provincial Key Laboratory of Genetic & Developmental Disorders, Zhejiang Univesity, Hangzhou, Zhejiang, China; Division of Mitochondrial Biomedicine, Joint Institute of Genetics and Genome Medicine between Zhejiang University and University of Toronto, Hangzhou, Zhejiang, China.
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31
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Müller‐Nedebock AC, Westhuizen FH, Kõks S, Bardien S. Nuclear Genes Associated with Mitochondrial
DNA
Processes as Contributors to Parkinson's Disease Risk. Mov Disord 2021; 36:815-831. [DOI: 10.1002/mds.28475] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 12/07/2020] [Accepted: 12/16/2020] [Indexed: 12/11/2022] Open
Affiliation(s)
- Amica C. Müller‐Nedebock
- Division of Molecular Biology and Human Genetics, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences Stellenbosch University Cape Town South Africa
| | | | - Sulev Kõks
- Perron Institute for Neurological and Translational Science Nedlands Western Australia Australia
- Centre for Molecular Medicine and Innovative Therapeutics Murdoch University Murdoch Western Australia Australia
| | - Soraya Bardien
- Division of Molecular Biology and Human Genetics, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences Stellenbosch University Cape Town South Africa
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Uittenbogaard M, Sen K, Whitehead M, Brantner CA, Wang Y, Wong LJ, Gropman A, Chiaramello A. Genetic and Mitochondrial Metabolic Analyses of an Atypical Form of Leigh Syndrome. Front Cell Dev Biol 2021; 9:767407. [PMID: 35004675 PMCID: PMC8728009 DOI: 10.3389/fcell.2021.767407] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Accepted: 12/10/2021] [Indexed: 11/13/2022] Open
Abstract
In this study, we aimed to establish the mitochondrial etiology of the proband's progressive neurodegenerative disease suggestive of an atypical Leigh syndrome, by determining the proband's pathogenic variants. Brain MRI showed a constellation of multifocal temporally disparate lesions in the cerebral deep gray nuclei, brainstem, cerebellum, spinal cord along with rhombencephalic atrophy, and optic nerve atrophy. Single voxel 1H MRS performed concurrently over the left cerebral deep gray nuclei showed a small lactate peak, increased glutamate and citrate elevation, elevating suspicion of a mitochondrial etiology. Whole exome sequencing revealed three heterozygous nuclear variants mapping in three distinct genes known to cause Leigh syndrome. Our mitochondrial bioenergetic investigations revealed an impaired mitochondrial energy metabolism. The proband's overall ATP deficit is further intensified by an ineffective metabolic reprogramming between oxidative phosphorylation and glycolysis. The deficient metabolic adaptability and global energy deficit correlate with the proband's neurological symptoms congruent with an atypical Leigh syndrome. In conclusion, our study provides much needed insights to support the development of molecular diagnostic and therapeutic strategies for atypical Leigh syndrome.
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Affiliation(s)
- Martine Uittenbogaard
- Department of Anatomy and Cell Biology, George Washington University School of Medicine and Health Sciences, Washington, DC, United States
| | - Kuntal Sen
- Children’s National Medical Center, Division of Neurogenetics and Developmental Pediatrics, Washington, DC, United States
| | - Matthew Whitehead
- Children’s National Medical Center, Division of Radiology, Washington, DC, United States
| | - Christine A. Brantner
- GW Nanofabrication and Imaging Center, Office of the Vice President for Research, George Washington University, Washington, DC, United States
| | - Yue Wang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Lee-Jun Wong
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Andrea Gropman
- Children’s National Medical Center, Division of Neurogenetics and Developmental Pediatrics, Washington, DC, United States
| | - Anne Chiaramello
- Department of Anatomy and Cell Biology, George Washington University School of Medicine and Health Sciences, Washington, DC, United States
- *Correspondence: Anne Chiaramello, , orcid.org/0000-0001-8424-0826
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Balasubramaniam S, Shah R. Clinical phenotype of FASTKD2 mutation. J Pediatr Neurosci 2021; 16:319-322. [DOI: 10.4103/jpn.jpn_199_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Revised: 10/03/2020] [Accepted: 03/28/2021] [Indexed: 11/05/2022] Open
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Ferrari A, Del'Olio S, Barrientos A. The Diseased Mitoribosome. FEBS Lett 2020; 595:1025-1061. [PMID: 33314036 DOI: 10.1002/1873-3468.14024] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 12/03/2020] [Accepted: 12/06/2020] [Indexed: 12/17/2022]
Abstract
Mitochondria control life and death in eukaryotic cells. Harboring a unique circular genome, a by-product of an ancient endosymbiotic event, mitochondria maintains a specialized and evolutionary divergent protein synthesis machinery, the mitoribosome. Mitoribosome biogenesis depends on elements encoded in both the mitochondrial genome (the RNA components) and the nuclear genome (all ribosomal proteins and assembly factors). Recent cryo-EM structures of mammalian mitoribosomes have illuminated their composition and provided hints regarding their assembly and elusive mitochondrial translation mechanisms. A growing body of literature involves the mitoribosome in inherited primary mitochondrial disorders. Mutations in genes encoding mitoribosomal RNAs, proteins, and assembly factors impede mitoribosome biogenesis, causing protein synthesis defects that lead to respiratory chain failure and mitochondrial disorders such as encephalo- and cardiomyopathy, deafness, neuropathy, and developmental delays. In this article, we review the current fundamental understanding of mitoribosome assembly and function, and the clinical landscape of mitochondrial disorders driven by mutations in mitoribosome components and assembly factors, to portray how basic and clinical studies combined help us better understand both mitochondrial biology and medicine.
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Affiliation(s)
- Alberto Ferrari
- Department of Neurology, University of Miami Miller School of Medicine, FL, USA
| | - Samuel Del'Olio
- Department of Neurology, University of Miami Miller School of Medicine, FL, USA.,Molecular and Cellular Pharmacology Graduate Program, University of Miami Miller School of Medicine, FL, USA
| | - Antoni Barrientos
- Department of Neurology, University of Miami Miller School of Medicine, FL, USA.,Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, FL, USA
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Proteomic Characterization of Synaptosomes from Human Substantia Nigra Indicates Altered Mitochondrial Translation in Parkinson's Disease. Cells 2020; 9:cells9122580. [PMID: 33276480 PMCID: PMC7761546 DOI: 10.3390/cells9122580] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 11/17/2020] [Accepted: 11/24/2020] [Indexed: 12/25/2022] Open
Abstract
The pathological hallmark of Parkinson's disease (PD) is the loss of neuromelanin-containing dopaminergic neurons within the substantia nigra pars compacta (SNpc). Additionally, numerous studies indicate an altered synaptic function during disease progression. To gain new insights into the molecular processes underlying the alteration of synaptic function in PD, a proteomic study was performed. Therefore, synaptosomes were isolated by density gradient centrifugation from SNpc tissue of individuals at advanced PD stages (N = 5) as well as control subjects free of pathology (N = 5) followed by mass spectrometry-based analysis. In total, 362 proteins were identified and assigned to the synaptosomal core proteome. This core proteome comprised all proteins expressed within the synapses without regard to data analysis software, gender, age, or disease. The differential analysis between control subjects and PD cases revealed that CD9 antigen was overrepresented and fourteen proteins, among them Thymidine kinase 2 (TK2), mitochondrial, 39S ribosomal protein L37, neurolysin, and Methionine-tRNA ligase (MARS2) were underrepresented in PD suggesting an alteration in mitochondrial translation within synaptosomes.
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36
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Leuzzi V, Nardecchia F, Pons R, Galosi S. Parkinsonism in children: Clinical classification and etiological spectrum. Parkinsonism Relat Disord 2020; 82:150-157. [PMID: 33109474 DOI: 10.1016/j.parkreldis.2020.10.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Revised: 07/14/2020] [Accepted: 10/03/2020] [Indexed: 01/03/2023]
Abstract
Infantile- and childhood-onset parkinsonism is mainly due to genetic alterations and is an exceedingly rare condition, unlike Parkinson's disease (PD), which is one of the most common neurologic disorders in adulthood. The clinical characterization of parkinsonism during early stages of neuromotor development is controversial due to the lack of consensus regarding the clinical criteria of PD or parkinsonism in the immature brain. The classification here proposed is based on a review of conditions that emerge during infancy and childhood, with key symptoms evocative of adult parkinsonism. The proposed nosography is based on age at presentation, clinical features, outcome, and etiological background. It includes developmental parkinsonism, infantile degenerative parkinsonism, parkinsonism in the setting of neurodevelopmental disorders, parkinsonism in the setting of multisystem brain diseases, juvenile parkinsonism and dystonia-parkinsonism, and acquired parkinsonism. The subgroups denoting peculiar clinical presentations as a consequence of disease impact on the immature brain are developmental parkinsonism due to monoamine metabolic disorders and infantile degenerative parkinsonism caused by DAT and WASR2 defects. More tardive parkinsonisms occur in genetic conditions that cause a generalized derangement of neurodevelopmental processes, such as those due to MECP2, NR4A2, SCN1A, and RAB39B. Some conditions presenting with neurodevelopmental disorder can progress later, disclosing their neurodegenerative nature (i.e. WDR45 and KCND3). Finally, new emerging conditions with childhood-onset parkinsonism arise from the cumulative effect of multiple genetic lesions.
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Affiliation(s)
- Vincenzo Leuzzi
- Department of Human Neuroscience, Sapienza University of Rome, Italy.
| | | | - Roser Pons
- First Department of Pediatrics, National and Kapodistrian University of Athens, Medical School, Agia Sophia Children's Hospital, Athens, Greece
| | - Serena Galosi
- Department of Human Neuroscience, Sapienza University of Rome, Italy
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Mechanisms Underlying the Regulation of Mitochondrial Respiratory Chain Complexes by Nuclear Steroid Receptors. Int J Mol Sci 2020; 21:ijms21186683. [PMID: 32932692 PMCID: PMC7555717 DOI: 10.3390/ijms21186683] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Revised: 09/09/2020] [Accepted: 09/10/2020] [Indexed: 12/30/2022] Open
Abstract
Mitochondrial respiratory chain complexes play important roles in energy production via oxidative phosphorylation (OXPHOS) to drive various biochemical processes in eukaryotic cells. These processes require coordination with other cell organelles, especially the nucleus. Factors encoded by both nuclear and mitochondrial DNA are involved in the formation of active respiratory chain complexes and 'supercomplexes', the higher-order structures comprising several respiratory chain complexes. Various nuclear hormone receptors are involved in the regulation of OXPHOS-related genes. In this article, we review the roles of nuclear steroid receptors (NR3 class nuclear receptors), including estrogen receptors (ERs), estrogen-related receptors (ERRs), glucocorticoid receptors (GRs), mineralocorticoid receptors (MRs), progesterone receptors (PRs), and androgen receptors (ARs), in the regulatory mechanisms of mitochondrial respiratory chain complex and supercomplex formation.
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38
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Schon KR, Ratnaike T, van den Ameele J, Horvath R, Chinnery PF. Mitochondrial Diseases: A Diagnostic Revolution. Trends Genet 2020; 36:702-717. [PMID: 32674947 DOI: 10.1016/j.tig.2020.06.009] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 06/18/2020] [Accepted: 06/19/2020] [Indexed: 12/26/2022]
Abstract
Mitochondrial disorders have emerged as a common cause of inherited disease, but are traditionally viewed as being difficult to diagnose clinically, and even more difficult to comprehensively characterize at the molecular level. However, new sequencing approaches, particularly whole-genome sequencing (WGS), have dramatically changed the landscape. The combined analysis of nuclear and mitochondrial DNA (mtDNA) allows rapid diagnosis for the vast majority of patients, but new challenges have emerged. We review recent discoveries that will benefit patients and families, and highlight emerging questions that remain to be resolved.
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Affiliation(s)
- Katherine R Schon
- Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK; Medical Research Council (MRC) Mitochondrial Biology Unit, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK
| | - Thiloka Ratnaike
- Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK; Medical Research Council (MRC) Mitochondrial Biology Unit, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK; Department of Paediatrics, 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 (MRC) Mitochondrial Biology Unit, 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
| | - Patrick F Chinnery
- Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK; Medical Research Council (MRC) Mitochondrial Biology Unit, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK.
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39
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Aibara S, Singh V, Modelska A, Amunts A. Structural basis of mitochondrial translation. eLife 2020; 9:58362. [PMID: 32812867 PMCID: PMC7438116 DOI: 10.7554/elife.58362] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 07/28/2020] [Indexed: 12/14/2022] Open
Abstract
Translation of mitochondrial messenger RNA (mt-mRNA) is performed by distinct mitoribosomes comprising at least 36 mitochondria-specific proteins. How these mitoribosomal proteins assist in the binding of mt-mRNA and to what extent they are involved in the translocation of transfer RNA (mt-tRNA) is unclear. To visualize the process of translation in human mitochondria, we report ~3.0 Å resolution structure of the human mitoribosome, including the L7/L12 stalk, and eight structures of its functional complexes with mt-mRNA, mt-tRNAs, recycling factor and additional trans factors. The study reveals a transacting protein module LRPPRC-SLIRP that delivers mt-mRNA to the mitoribosomal small subunit through a dedicated platform formed by the mitochondria-specific protein mS39. Mitoribosomal proteins of the large subunit mL40, mL48, and mL64 coordinate translocation of mt-tRNA. The comparison between those structures shows dynamic interactions between the mitoribosome and its ligands, suggesting a sequential mechanism of conformational changes.
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Affiliation(s)
- Shintaro Aibara
- Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, Solna, Sweden
| | - Vivek Singh
- Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, Solna, Sweden.,Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Angelika Modelska
- Laboratory of Translational Genomics, Centre for Integrative Biology, University of Trento, Trento, Italy
| | - Alexey Amunts
- Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, Solna, Sweden.,Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
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40
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Reyes A, Favia P, Vidoni S, Petruzzella V, Zeviani M. RCC1L (WBSCR16) isoforms coordinate mitochondrial ribosome assembly through their interaction with GTPases. PLoS Genet 2020; 16:e1008923. [PMID: 32735630 PMCID: PMC7423155 DOI: 10.1371/journal.pgen.1008923] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 08/12/2020] [Accepted: 06/10/2020] [Indexed: 12/12/2022] Open
Abstract
Mitochondrial translation defects can be due to mutations affecting mitochondrial- or nuclear-encoded components. The number of known nuclear genes involved in mitochondrial translation has significantly increased in the past years. RCC1L (WBSCR16), a putative GDP/GTP exchange factor, has recently been described to interact with the mitochondrial large ribosomal subunit. In humans, three different RCC1L isoforms have been identified that originate from alternative splicing but share the same N-terminus, RCC1LV1, RCC1LV2 and RCC1LV3. All three isoforms were exclusively localized to mitochondria, interacted with its inner membrane and could associate with homopolymeric oligos to different extent. Mitochondrial immunoprecipitation experiments showed that RCC1LV1 and RCC1LV3 associated with the mitochondrial large and small ribosomal subunit, respectively, while no significant association was observed for RCC1LV2. Overexpression and silencing of RCC1LV1 or RCC1LV3 led to mitoribosome biogenesis defects that resulted in decreased translation. Indeed, significant changes in steady-state levels and distribution on isokinetic sucrose gradients were detected not only for mitoribosome proteins but also for GTPases, (GTPBP10, ERAL1 and C4orf14), and pseudouridylation proteins, (TRUB2, RPUSD3 and RPUSD4). All in all, our data suggest that RCC1L is essential for mitochondrial function and that the coordination of at least two isoforms is essential for proper ribosomal assembly.
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Affiliation(s)
- Aurelio Reyes
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, United Kingdom
- * E-mail:
| | - Paola Favia
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, United Kingdom
- Dipartimento di Scienze Mediche di Base, Neuroscienze e Organi di Senso - Università degli Studi Aldo Moro, Piazza G. Cesare, Bari, Italy
| | - Sara Vidoni
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, United Kingdom
| | - Vittoria Petruzzella
- Dipartimento di Scienze Mediche di Base, Neuroscienze e Organi di Senso - Università degli Studi Aldo Moro, Piazza G. Cesare, Bari, Italy
| | - Massimo Zeviani
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, United Kingdom
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41
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Bennett J, Kerr M, Greenway SC, Friederich MW, Van Hove JL, Hittel D, Khan A. Improved lactate control with dichloroacetate in a case with severe neonatal lactic acidosis due to MTFMT mitochondrial translation disorder. Mol Genet Metab Rep 2020; 24:100616. [PMID: 32577402 PMCID: PMC7303673 DOI: 10.1016/j.ymgmr.2020.100616] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 05/20/2020] [Accepted: 05/21/2020] [Indexed: 01/17/2023] Open
Abstract
Mitochondrial methionyl-tRNA formyltransferase (MTFMT) is a nuclear-encoded gene that produces a protein involved in mitochondrial translation. MTFMT formylates a portion of Met-tRNAMet, which allows for translation initiation of mitochondrial mRNA. Mutations in this gene have been shown to result in decreased mitochondrial translation with reduction function of the electron transport chain complexes I, III, IV, and V, thus affecting cellular energy production. Our patient presented with severe lactic acidosis in the neonatal period, and was found to be homozygous for the pathogenic mutation c.994C > T, p.(Arg332*). Her blood lactate levels normalized and her cardiomyopathy reversed after initiation of dichloroacetate (30 mg/kg/day). After two years of follow-up, she continues to show long-term lactate stability, continues to make developmental gains, and is in overall good general health. This is the first report using dichloroacetate in a patient with MTFMT deficiency, which may be a potential therapeutic option that warrants further study.
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Affiliation(s)
- Jennifer Bennett
- Department of Medical Genetics and Pediatrics, Alberta Children's Hospital, Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Marina Kerr
- Department of Medical Genetics and Pediatrics, Alberta Children's Hospital, Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Steven C. Greenway
- Departments of Pediatrics, Cardiac Sciences, Biochemistry & Molecular Biology, Alberta Children's Hospital Research Institute, Libin Cardiovascular Institute of Alberta, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Marisa W. Friederich
- Section of Clinical Genetics and Metabolism, Department of Pediatrics, University of Colorado, Aurora, CO, USA
- Department of Pathology and Laboratory Medicine, Children's Hospital Colorado, Aurora, CO, USA
| | - Johan L.K. Van Hove
- Section of Clinical Genetics and Metabolism, Department of Pediatrics, University of Colorado, Aurora, CO, USA
- Department of Pathology and Laboratory Medicine, Children's Hospital Colorado, Aurora, CO, USA
| | - Dustin Hittel
- Department of Biochemistry & Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Aneal Khan
- Department of Medical Genetics and Pediatrics, Alberta Children's Hospital, Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Corresponding author at: Alberta Children's Hospital, 28 Oki Drive NW, Calgary, Alberta T3B 6A8, Canada.
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42
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Wang W, Zhao F, Ma X, Perry G, Zhu X. Mitochondria dysfunction in the pathogenesis of Alzheimer's disease: recent advances. Mol Neurodegener 2020; 15:30. [PMID: 32471464 PMCID: PMC7257174 DOI: 10.1186/s13024-020-00376-6] [Citation(s) in RCA: 510] [Impact Index Per Article: 127.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 04/24/2020] [Indexed: 12/22/2022] Open
Abstract
Alzheimer's disease (AD) is one of the most prevalent neurodegenerative diseases, characterized by impaired cognitive function due to progressive loss of neurons in the brain. Under the microscope, neuronal accumulation of abnormal tau proteins and amyloid plaques are two pathological hallmarks in affected brain regions. Although the detailed mechanism of the pathogenesis of AD is still elusive, a large body of evidence suggests that damaged mitochondria likely play fundamental roles in the pathogenesis of AD. It is believed that a healthy pool of mitochondria not only supports neuronal activity by providing enough energy supply and other related mitochondrial functions to neurons, but also guards neurons by minimizing mitochondrial related oxidative damage. In this regard, exploration of the multitude of mitochondrial mechanisms altered in the pathogenesis of AD constitutes novel promising therapeutic targets for the disease. In this review, we will summarize recent progress that underscores the essential role of mitochondria dysfunction in the pathogenesis of AD and discuss mechanisms underlying mitochondrial dysfunction with a focus on the loss of mitochondrial structural and functional integrity in AD including mitochondrial biogenesis and dynamics, axonal transport, ER-mitochondria interaction, mitophagy and mitochondrial proteostasis.
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Affiliation(s)
- Wenzhang Wang
- Department of Pathology, Case Western Reserve University, 2103 Cornell Road, Cleveland, OH, 44106, USA.
| | - Fanpeng Zhao
- Department of Pathology, Case Western Reserve University, 2103 Cornell Road, Cleveland, OH, 44106, USA
| | - Xiaopin Ma
- Department of Pathology, Case Western Reserve University, 2103 Cornell Road, Cleveland, OH, 44106, USA
| | - George Perry
- College of Sciences, University of Texas at San Antonio, San Antonio, TX, USA.
| | - Xiongwei Zhu
- Department of Pathology, Case Western Reserve University, 2103 Cornell Road, Cleveland, OH, 44106, USA.
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43
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Slade A, Kattini R, Campbell C, Holcik M. Diseases Associated with Defects in tRNA CCA Addition. Int J Mol Sci 2020; 21:E3780. [PMID: 32471101 PMCID: PMC7312816 DOI: 10.3390/ijms21113780] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 05/21/2020] [Accepted: 05/22/2020] [Indexed: 02/06/2023] Open
Abstract
tRNA nucleotidyl transferase 1 (TRNT1) is an essential enzyme catalyzing the addition of terminal cytosine-cytosine-adenosine (CCA) trinucleotides to all mature tRNAs, which is necessary for aminoacylation. It was recently discovered that partial loss-of-function mutations in TRNT1 are associated with various, seemingly unrelated human diseases including sideroblastic anemia with B-cell immunodeficiency, periodic fevers and developmental delay (SIFD), retinitis pigmentosa with erythrocyte microcytosis, and progressive B-cell immunodeficiency. In addition, even within the same disease, the severity and range of the symptoms vary greatly, suggesting a broad, pleiotropic impact of imparting TRNT1 function on diverse cellular systems. Here, we describe the current state of knowledge of the TRNT1 function and the phenotypes associated with mutations in TRNT1.
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Affiliation(s)
| | | | | | - Martin Holcik
- Department of Health Sciences, Carleton University, Ottawa, ON K1S 5B6, Canada; (A.S.); (R.K.); (C.C.)
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44
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Peng W, Zhong Y, Zhao X, Yuan J. Low penetrance of hearing loss in two Chinese families carrying the mitochondrial tRNASer(UCN) mutations. Mol Med Rep 2020; 22:77-86. [PMID: 32377700 PMCID: PMC7248462 DOI: 10.3892/mmr.2020.11100] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2019] [Accepted: 02/20/2020] [Indexed: 01/07/2023] Open
Abstract
Mutations in mitochondrial DNA (mtDNA), especially in mitochondrial 12S rRNA and transfer RNA(tRNA)Ser(UCN) genes, are important causes of non-syndromic hearing loss. However, the molecular mechanism underlying mt-tRNA mutations in clinical hearing impairment are not fully understood. The present study assessed the molecular characterization of two Chinese families with non-syndromic hearing loss, who both exhibited very low penetrance of deafness (9.1 and 12.5% for Family 1 and 2, respectively). Mutational analysis of the complete mtDNA genes identified the presence of cytochrome c oxidase 1/tRNASer(UCN) G7444A and tRNASer(UCN) C7492T mutations, together with polymorphisms belonging to human mitochondrial haplogroup D4 and G2b, respectively. Moreover, the G7444A and C7492T mutations occurred at highly conserved tRNASer(UCN) nucleotides and may cause tRNA metabolism failure, which is involved in mitochondrial translation defects. Therefore, the G7444A and C7492T mutations may lead to the mitochondrial dysfunction that responsible for deafness. However, the absence of any functional variants in Gap junction β-2, Solute Carrier Family 26 Member 4 and TRNA 5-methylaminomethyl-2-thiouridylate methyltransferase suggested that nuclear genes may not play active roles in the occurrence of deafness. In the present study, the observed incomplete penetrance of hearing loss and mild mitochondrial dysfunction indicated that mtDNA G7444A and C7492T mutations are insufficient to produce the deafness phenotype. Therefore, other risk factors such as environmental factors and epigenetic regulation may be involved in the pathogenesis of hearing loss in the families recruited in the present study.
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Affiliation(s)
- Wei Peng
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, P.R. China
| | - Yi Zhong
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, P.R. China
| | - Xueyan Zhao
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, P.R. China
| | - Jie Yuan
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, P.R. China
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45
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Waltz F, Corre N, Hashem Y, Giegé P. Specificities of the plant mitochondrial translation apparatus. Mitochondrion 2020; 53:30-37. [PMID: 32334144 DOI: 10.1016/j.mito.2020.04.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 04/14/2020] [Accepted: 04/21/2020] [Indexed: 12/16/2022]
Abstract
Mitochondria are endosymbiotic organelles responsible for energy production in most eukaryotic cells. They host a genome and a fully functional gene expression machinery. In plants this machinery involves hundreds of pentatricopeptide repeat (PPR) proteins. Translation, the final step of mitochondrial gene expression is performed by mitochondrial ribosomes (mitoribosomes). The nature of these molecular machines remained elusive for a very long time. Because of their bacterial origin, it was expected that mitoribosomes would closely resemble bacterial ribosomes. However, recent advances in cryo-electron microscopy have revealed the extraordinary diversity of mitoribosome structure and composition. The plant mitoribosome was characterized for Arabidopsis. In plants, in contrast to other species such as mammals and kinetoplastids where rRNA has been largely reduced, the mitoribosome could be described as a protein/RNA-augmented bacterial ribosome. It has an oversized small subunit formed by expanded ribosomal RNAs and additional protein components when compared to bacterial ribosomes. The same holds true for the large subunit. The small subunit is characterized by a new elongated domain on the head. Among its additional proteins, several PPR proteins are core mitoribosome proteins. They mainly act at the structural level to stabilize and maintain the plant-specific ribosomal RNA expansions but could also be involved in translation initiation. Recent advances in plant mitoribosome composition and structure, its specialization for membrane protein synthesis, translation initiation, the regulation and dynamics of mitochondrial translation are reviewed here and put in perspective with the diversity of mitochondrial translation processes in the green lineage and in the wider context of eukaryote evolution.
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Affiliation(s)
- Florent Waltz
- Institut Européen de Chimie et Biologie, U1212 Inserm, Université de Bordeaux, 2 rue R. Escarpit, F 33600 Pessac, France
| | - Nicolas Corre
- Institut de biologie de moléculaire des plantes, CNRS, Université de Strasbourg, 12 rue du général Zimmer, F 67084 Strasbourg, France
| | - Yaser Hashem
- Institut Européen de Chimie et Biologie, U1212 Inserm, Université de Bordeaux, 2 rue R. Escarpit, F 33600 Pessac, France
| | - Philippe Giegé
- Institut de biologie de moléculaire des plantes, CNRS, Université de Strasbourg, 12 rue du général Zimmer, F 67084 Strasbourg, France.
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46
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Reyes A, Rusecka J, Tońska K, Zeviani M. RNase H1 Regulates Mitochondrial Transcription and Translation via the Degradation of 7S RNA. Front Genet 2020; 10:1393. [PMID: 32082360 PMCID: PMC7006045 DOI: 10.3389/fgene.2019.01393] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 12/19/2019] [Indexed: 02/02/2023] Open
Abstract
RNase H1 is able to recognize DNA/RNA heteroduplexes and to degrade their RNA component. As a consequence, it has been implicated in different aspects of mtDNA replication such as primer formation, primer removal, and replication termination, and significant differences have been reported between control and mutant RNASEH1 skin fibroblasts from patients. However, neither mtDNA depletion nor the presence of deletions have been described in skin fibroblasts while still presenting signs of mitochondrial dysfunction (lower mitochondrial membrane potential, reduced oxygen consumption, slow growth in galactose). Here, we show that RNase H1 has an effect on mtDNA transcripts, most likely through the regulation of 7S RNA and other R-loops. The observed effect on both mitochondrial mRNAs and 16S rRNA results in decreased mitochondrial translation and subsequently mitochondrial dysfunction in cells carrying mutations in RNASEH1.
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Affiliation(s)
- Aurelio Reyes
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, United Kingdom,*Correspondence: Aurelio Reyes, ; Massimo Zeviani,
| | - Joanna Rusecka
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, United Kingdom,Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Warsaw, Poland
| | - Katarzyna Tońska
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Warsaw, Poland
| | - Massimo Zeviani
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, United Kingdom,*Correspondence: Aurelio Reyes, ; Massimo Zeviani,
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47
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Abstract
RNA species play host to a plethora of post-transcriptional modifications which together make up the epitranscriptome. 5-methyluridine (m5U) is one of the most common modifications made to cellular RNA, where it is found almost ubiquitously in bacterial and eukaryotic cytosolic tRNAs at position 54. Here, we demonstrate that m5U54 in human mitochondrial tRNAs is catalysed by the nuclear-encoded enzyme TRMT2B, and that its repertoire of substrates is expanded to ribosomal RNAs, catalysing m5U429 in 12S rRNA. We show that TRMT2B is not essential for viability in human cells and that knocking-out the gene shows no obvious phenotype with regards to RNA stability, mitochondrial translation, or cellular growth.
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Affiliation(s)
- Christopher A Powell
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge, UK
| | - Michal Minczuk
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge, UK
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48
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Fine AS, Nemeth CL, Kaufman ML, Fatemi A. Mitochondrial aminoacyl-tRNA synthetase disorders: an emerging group of developmental disorders of myelination. J Neurodev Disord 2019; 11:29. [PMID: 31839000 PMCID: PMC6913031 DOI: 10.1186/s11689-019-9292-y] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 11/11/2019] [Indexed: 12/30/2022] Open
Abstract
Background The mitochondrial aminoacyl-tRNA synthetase proteins (mt-aaRSs) are a group of nuclear-encoded enzymes that facilitate conjugation of each of the 20 amino acids to its cognate tRNA molecule. Mitochondrial diseases are a large, clinically heterogeneous group of disorders with diverse etiologies, ages of onset, and involved organ systems. Diseases related to mt-aaRS mutations are associated with specific syndromes that affect the central nervous system and produce highly characteristic MRI patterns, prototypically the DARS2, EARS, and AARS2 leukodystrophies, which are caused by mutations in mitochondrial aspartyl-tRNA synthetase, mitochondria glutamate tRNA synthetase, and mitochondrial alanyl-tRNA synthetase, respectively. Body The disease patterns emerging for these leukodystrophies are distinct in terms of the age of onset, nature of disease progression, and predominance of involved white matter tracts. In DARS2 and EARS2 disorders, earlier disease onset is typically correlated with more significant brain abnormalities, rapid neurological decline, and greater disability. In AARS2 leukodystrophy cases reported thus far, there is nearly invariable progression to severe disability and atrophy of involved brain regions, often within a decade. Although most mutations are compound heterozygous inherited in an autosomal recessive fashion, homozygous variants are found in each disorder and demonstrate high phenotypic variability. Affected siblings manifest disease on a wide spectrum. Conclusion The syndromic nature and selective vulnerability of white matter tracts in these disorders suggests there may be a shared mechanism of mitochondrial dysfunction to target for study. There is evidence that the clinical variability and white matter tract specificity of each mt-aaRS leukodystrophy depend on both canonical and non-canonical effects of the mutations on the process of mitochondrial translation. Furthermore, different sensitivities to the mt-aaRS mutations have been observed based on cell type. Most mutations result in at least partial retention of mt-aaRS enzyme function with varied effects on the mitochondrial respiratory chain complexes. In EARS2 and AARS2 cells, this appears to result in cumulative impairment of respiration. Mt-aaRS mutations may also affect alternative biochemical pathways such as the integrated stress response, a homeostatic program in eukaryotic cells that typically confers cytoprotection, but can lead to cell death when abnormally activated in response to pathologic states. Systematic review of this group of disorders and further exploration of disease mechanisms in disease models and neural cells are warranted.
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Affiliation(s)
- Amena Smith Fine
- Moser Center for Leukodystrophies at the Kennedy Krieger Institute, Baltimore, MD, 21205, USA. .,Department of Neurology and Developmental Medicine, Kennedy Krieger Institute, Baltimore, MD, 21205, USA.
| | - Christina L Nemeth
- Moser Center for Leukodystrophies at the Kennedy Krieger Institute, Baltimore, MD, 21205, USA.,Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, USA
| | - Miriam L Kaufman
- Moser Center for Leukodystrophies at the Kennedy Krieger Institute, Baltimore, MD, 21205, USA.,Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, USA
| | - Ali Fatemi
- Moser Center for Leukodystrophies at the Kennedy Krieger Institute, Baltimore, MD, 21205, USA.,Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, USA
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49
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Van Haute L, Hendrick AG, D'Souza AR, Powell CA, Rebelo-Guiomar P, Harbour ME, Ding S, Fearnley IM, Andrews B, Minczuk M. METTL15 introduces N4-methylcytidine into human mitochondrial 12S rRNA and is required for mitoribosome biogenesis. Nucleic Acids Res 2019; 47:10267-10281. [PMID: 31665743 PMCID: PMC6821322 DOI: 10.1093/nar/gkz735] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Accepted: 09/03/2019] [Indexed: 01/08/2023] Open
Abstract
Post-transcriptional RNA modifications, the epitranscriptome, play important roles in modulating the functions of RNA species. Modifications of rRNA are key for ribosome production and function. Identification and characterization of enzymes involved in epitranscriptome shaping is instrumental for the elucidation of the functional roles of specific RNA modifications. Ten modified sites have been thus far identified in the mammalian mitochondrial rRNA. Enzymes responsible for two of these modifications have not been characterized. Here, we identify METTL15, show that it is the main N4-methylcytidine (m4C) methyltransferase in human cells and demonstrate that it is responsible for the methylation of position C839 in mitochondrial 12S rRNA. We show that the lack of METTL15 results in a reduction of the mitochondrial de novo protein synthesis and decreased steady-state levels of protein components of the oxidative phosphorylation system. Without functional METTL15, the assembly of the mitochondrial ribosome is decreased, with the late assembly components being unable to be incorporated efficiently into the small subunit. We speculate that m4C839 is involved in the stabilization of 12S rRNA folding, therefore facilitating the assembly of the mitochondrial small ribosomal subunits. Taken together our data show that METTL15 is a novel protein necessary for efficient translation in human mitochondria.
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Affiliation(s)
- Lindsey Van Haute
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Hills Road, Cambridge CB2 0XY, UK
| | - Alan G Hendrick
- STORM Therapeutics Limited, Moneta Building, Babraham Research Campus, Cambridge CB22 3AT, UK
| | - Aaron R D'Souza
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Hills Road, Cambridge CB2 0XY, UK
| | - Christopher A Powell
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Hills Road, Cambridge CB2 0XY, UK
| | - Pedro Rebelo-Guiomar
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Hills Road, Cambridge CB2 0XY, UK.,Graduate Program in Areas of Basic and Applied Biology (GABBA), University of Porto, Rua Alfredo Allen 208, Porto 4200-135, Portugal
| | - Michael E Harbour
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Hills Road, Cambridge CB2 0XY, UK.,STORM Therapeutics Limited, Moneta Building, Babraham Research Campus, Cambridge CB22 3AT, UK
| | - Shujing Ding
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Hills Road, Cambridge CB2 0XY, UK
| | - Ian M Fearnley
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Hills Road, Cambridge CB2 0XY, UK
| | - Byron Andrews
- STORM Therapeutics Limited, Moneta Building, Babraham Research Campus, Cambridge CB22 3AT, UK
| | - Michal Minczuk
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Hills Road, Cambridge CB2 0XY, UK
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50
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Zhao X, Cui L, Xiao Y, Mao Q, Aishanjiang M, Kong W, Liu Y, Chen H, Hong F, Jia Z, Wang M, Jiang P, Guan MX. Hypertension-associated mitochondrial DNA 4401A>G mutation caused the aberrant processing of tRNAMet, all 8 tRNAs and ND6 mRNA in the light-strand transcript. Nucleic Acids Res 2019; 47:10340-10356. [PMID: 31504769 PMCID: PMC6821173 DOI: 10.1093/nar/gkz742] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Revised: 08/12/2019] [Accepted: 08/22/2019] [Indexed: 12/31/2022] Open
Abstract
Mitochondrial tRNA processing defects were associated with human diseases but their pathophysiology remains elusively. The hypertension-associated m.4401A>G mutation resided at a spacer between mitochondrial tRNAMet and tRNAGln genes. An in vitro processing experiment revealed that the m.4401A>G mutation caused 59% and 69% decreases in the 5' end processing efficiency of tRNAGln and tRNAMet precursors, catalyzed by RNase P, respectively. Using human umbilical vein endothelial cells-derived cybrids, we demonstrated that the m.4401A>G mutation caused the decreases of all 8 tRNAs and ND6 and increases of longer and uncleaved precursors from the Light-strand transcript. Conversely, the m.4401A>G mutation yielded the reduced levels of tRNAMet level but did not change the levels of other 13 tRNAs, 12 mRNAs including ND1, 12S rRNA and 16S rRNA from the Heavy-strand transcript. These implicated the asymmetrical processing mechanisms of H-strand and L-strand polycistronic transcripts. The tRNA processing defects play the determined roles in the impairing mitochondrial translation, respiratory deficiency, diminishing membrane potential, increasing production of reactive oxygen species and altering autophagy. Furthermore, the m.4401A>G mutation altered the angiogenesis, evidenced by aberrant wound regeneration and weaken tube formation in mutant cybrids. Our findings provide new insights into the pathophysiology of hypertension arising from mitochondrial tRNA processing defects.
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Affiliation(s)
- Xiaoxu Zhao
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China.,Institute of Genetics, and Department of Human Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Limei Cui
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China.,Institute of Genetics, and Department of Human Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Yun Xiao
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China.,Institute of Genetics, and Department of Human Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Qin Mao
- Institute of Genetics, and Department of Human Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Maerhaba Aishanjiang
- Institute of Genetics, and Department of Human Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Wanzhong Kong
- Department of Clinical Laboratory, Wenzhou Traditional Chinese Medicine Hospital, Wenzhou, Zhejiang 325000, China
| | - Yuqi Liu
- Cardiac Department, Chinese PLA General Hospital, Beijing 100853, China
| | - Hong Chen
- Emergy Medicine Department, Ningbo First Hospital, Zhejiang University School of Medicine, Ningbo, Zhejiang 315000, China
| | - Fang Hong
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Zidong Jia
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China.,Institute of Genetics, and Department of Human Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Meng Wang
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China.,Institute of Genetics, and Department of Human Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Pingping Jiang
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China.,Institute of Genetics, and Department of Human Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Min-Xin Guan
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China.,Institute of Genetics, and Department of Human Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China.,Key lab of Reproductive Genetics, Ministry of Education of PRC, Zhejiang University, Hangzhou, Zhejiang 310058, China.,Joint Institute of Genetics and Genome Medicine between Zhejiang University and University of Toronto, Hangzhou, Zhejiang 310058, China
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