1
|
Kwak S, Hwang SK, Kwon MS, Chun BY. l-Serine Protects Murine Retinal Ganglion Cells from Oxidative Stress via Modulation of Mitochondrial Dysfunction. Curr Eye Res 2024:1-9. [PMID: 38771168 DOI: 10.1080/02713683.2024.2355661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Accepted: 05/11/2024] [Indexed: 05/22/2024]
Abstract
PURPOSE This study aimed to investigate the effects of l-serine on mitochondrial dysfunction in retinal ganglion cells after exposure to H2O2-induced oxidative stress. METHODS Retinal ganglion cells obtained from C57BL6 mice (postnatal days 1-4) were purified and cultured. A cell viability assay was performed following exposure to H2O2-induced oxidative stress to assess the cytoprotective effects of l-serine on retinal ganglion cells. Flow cytometry with CellROX Deep Red and MitoSOX dyes was performed to analyze the cytoplasmic and mitochondrial reactive oxygen species levels, respectively. Staining with the fluorescent probe JC-1 was used to detect changes in the mitochondrial membrane potential. The oxygen consumption rate and Bioenergetic Health Index were used to evaluate mitochondrial respiration. RESULTS H2O2 treatment was found to induce mitochondrial dysfunction in retinal ganglion cells. Pretreatment with l-serine prevented cytotoxicity and significantly increased the viability of retinal ganglion cells following exposure to H2O2-induced oxidative stress (p < .05). l-Serine alleviated reactive oxygen species production in retinal ganglion cells following exposure to H2O2-induced oxidative (p < .05). Further, it successfully mitigated H2O2-induced mitochondrial depolarization in retinal ganglion cells (p < .05) and significantly increased the oxygen consumption rate and Bioenergetic Health Index in retinal ganglion cells following exposure to H2O2-induced oxidative stress (p < .05). CONCLUSION Pretreatment with l-serine protected retinal ganglion cells from H2O2-induced oxidative stress by improving mitochondrial function. The findings of the present study suggest that l-serine is a potential candidate for treatment of reactive oxygen species-related ocular diseases such as mitochondrial optic neuropathies.
Collapse
Affiliation(s)
- Soyoung Kwak
- Astrogen Inc., Kyungpook National University, Daegu, South Korea
| | - Su-Kyeong Hwang
- Astrogen Inc., Kyungpook National University, Daegu, South Korea
- Department of Pediatrics, School of Medicine, Kyungpook National University, Daegu, South Korea
- School of Medicine, Brain Science & Engineering Institute, Kyungpook National University, Daegu, South Korea
| | - Mi Sun Kwon
- Department of Ophthalmology, School of Medicine, Kyungpook National University, Daegu, South Korea
| | - Bo Young Chun
- School of Medicine, Brain Science & Engineering Institute, Kyungpook National University, Daegu, South Korea
- Department of Ophthalmology, School of Medicine, Kyungpook National University, Daegu, South Korea
| |
Collapse
|
2
|
Pasqualotto BA, Tegeman C, Frame AK, McPhedrain R, Halangoda K, Sheldon CA, Rintoul GL. Galactose-replacement unmasks the biochemical consequences of the G11778A mitochondrial DNA mutation of LHON in patient-derived fibroblasts. Exp Cell Res 2024; 439:114075. [PMID: 38710404 DOI: 10.1016/j.yexcr.2024.114075] [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: 11/16/2023] [Revised: 04/30/2024] [Accepted: 05/03/2024] [Indexed: 05/08/2024]
Abstract
Leber's hereditary optic neuropathy (LHON) is a visual impairment associated with mutations of mitochondrial genes encoding elements of the electron transport chain. While much is known about the genetics of LHON, the cellular pathophysiology leading to retinal ganglion cell degeneration and subsequent vision loss is poorly understood. The impacts of the G11778A mutation of LHON on bioenergetics, redox balance and cell proliferation were examined in patient-derived fibroblasts. Replacement of glucose with galactose in the culture media reveals a deficit in the proliferation of G11778A fibroblasts, imparts a reduction in ATP biosynthesis, and a reduction in capacity to accommodate exogenous oxidative stress. While steady-state ROS levels were unaffected by the LHON mutation, cell survival was diminished in response to exogenous H2O2.
Collapse
Affiliation(s)
- Bryce A Pasqualotto
- Department of Biological Sciences and Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, BC, Canada
| | - Carina Tegeman
- Department of Biological Sciences and Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, BC, Canada
| | - Ariel K Frame
- Department of Biological Sciences and Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, BC, Canada
| | - Ryan McPhedrain
- Department of Biological Sciences and Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, BC, Canada
| | - Kolitha Halangoda
- Department of Biological Sciences and Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, BC, Canada
| | - Claire A Sheldon
- Dept. of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Gordon L Rintoul
- Department of Biological Sciences and Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, BC, Canada.
| |
Collapse
|
3
|
Aleo SJ, Del Dotto V, Romagnoli M, Fiorini C, Capirossi G, Peron C, Maresca A, Caporali L, Capristo M, Tropeano CV, Zanna C, Ross-Cisneros FN, Sadun AA, Pignataro MG, Giordano C, Fasano C, Cavaliere A, Porcelli AM, Tioli G, Musiani F, Catania A, Lamperti C, Marzoli SB, De Negri A, Cascavilla ML, Battista M, Barboni P, Carbonelli M, Amore G, La Morgia C, Smirnov D, Vasilescu C, Farzeen A, Blickhaeuser B, Prokisch H, Priglinger C, Livonius B, Catarino CB, Klopstock T, Tiranti V, Carelli V, Ghelli AM. Genetic variants affecting NQO1 protein levels impact the efficacy of idebenone treatment in Leber hereditary optic neuropathy. Cell Rep Med 2024; 5:101383. [PMID: 38272025 PMCID: PMC10897523 DOI: 10.1016/j.xcrm.2023.101383] [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: 01/05/2023] [Revised: 07/03/2023] [Accepted: 12/20/2023] [Indexed: 01/27/2024]
Abstract
Idebenone, the only approved treatment for Leber hereditary optic neuropathy (LHON), promotes recovery of visual function in up to 50% of patients, but we can neither predict nor understand the non-responders. Idebenone is reduced by the cytosolic NAD(P)H oxidoreductase I (NQO1) and directly shuttles electrons to respiratory complex III, bypassing complex I affected in LHON. We show here that two polymorphic variants drastically reduce NQO1 protein levels when homozygous or compound heterozygous. This hampers idebenone reduction. In its oxidized form, idebenone inhibits complex I, decreasing respiratory function in cells. By retrospectively analyzing a large cohort of idebenone-treated LHON patients, classified by their response to therapy, we show that patients with homozygous or compound heterozygous NQO1 variants have the poorest therapy response, particularly if carrying the m.3460G>A/MT-ND1 LHON mutation. These results suggest consideration of patient NQO1 genotype and mitochondrial DNA mutation in the context of idebenone therapy.
Collapse
Affiliation(s)
- Serena Jasmine Aleo
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Programma di Neurogenetica, Bologna, Italy; Departments of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy
| | - Valentina Del Dotto
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Programma di Neurogenetica, Bologna, Italy; Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Martina Romagnoli
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Programma di Neurogenetica, Bologna, Italy
| | - Claudio Fiorini
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Programma di Neurogenetica, Bologna, Italy
| | - Giada Capirossi
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Programma di Neurogenetica, Bologna, Italy; Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Camille Peron
- Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy
| | - Alessandra Maresca
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Programma di Neurogenetica, Bologna, Italy
| | - Leonardo Caporali
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Programma di Neurogenetica, Bologna, Italy; Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Mariantonietta Capristo
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Programma di Neurogenetica, Bologna, Italy
| | | | - Claudia Zanna
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | | | - Alfredo A Sadun
- Doheny Eye Institute, Pasadena, CA, USA; Department of Ophthalmology, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
| | - Maria Gemma Pignataro
- Departments of Radiology, Oncology, and Pathology, Sapienza, University of Rome, Rome, Italy
| | - Carla Giordano
- Departments of Radiology, Oncology, and Pathology, Sapienza, University of Rome, Rome, Italy
| | - Chiara Fasano
- Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy
| | - Andrea Cavaliere
- Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy
| | - Anna Maria Porcelli
- Departments of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy
| | - Gaia Tioli
- Departments of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy
| | - Francesco Musiani
- Departments of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy
| | - Alessia Catania
- Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy
| | - Costanza Lamperti
- Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy
| | - Stefania Bianchi Marzoli
- Neuro-Ophthalmology Center and Ocular Electrophysiology Laboratory, IRCCS Istituto Auxologico Italiano, Capitanio Hospital, Milan, Italy
| | | | | | | | | | - Michele Carbonelli
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Giulia Amore
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Chiara La Morgia
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Programma di Neurogenetica, Bologna, Italy; Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Dmitrii Smirnov
- Institute of Human Genetics, School of Medicine, Technische Universität München, Munich, Germany; Institute of Neurogenomics, Computational Health Center, Helmholtz Zentrum München, Munich, Germany
| | - Catalina Vasilescu
- Institute of Human Genetics, School of Medicine, Technische Universität München, Munich, Germany; Institute of Neurogenomics, Computational Health Center, Helmholtz Zentrum München, Munich, Germany
| | - Aiman Farzeen
- Institute of Human Genetics, School of Medicine, Technische Universität München, Munich, Germany; Institute of Neurogenomics, Computational Health Center, Helmholtz Zentrum München, Munich, Germany
| | - Beryll Blickhaeuser
- Institute of Human Genetics, School of Medicine, Technische Universität München, Munich, Germany; Institute of Neurogenomics, Computational Health Center, Helmholtz Zentrum München, Munich, Germany
| | - Holger Prokisch
- Institute of Human Genetics, School of Medicine, Technische Universität München, Munich, Germany; Institute of Neurogenomics, Computational Health Center, Helmholtz Zentrum München, Munich, Germany
| | - Claudia Priglinger
- Department of Ophthalmology, LMU University Hospital, LMU Munich, Munich, Germany
| | - Bettina Livonius
- Department of Ophthalmology, LMU University Hospital, LMU Munich, Munich, Germany
| | - Claudia B Catarino
- Department of Neurology, Friedrich Baur Institute, LMU Klinikum, University Hospital of the Ludwig-Maximilians-Universität München, Munich, Germany
| | - Thomas Klopstock
- Department of Neurology, Friedrich Baur Institute, LMU Klinikum, University Hospital of the Ludwig-Maximilians-Universität München, Munich, Germany; Munich Cluster for Systems Neurology (SyNergy), Munich, Germany; German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Valeria Tiranti
- Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy
| | - Valerio Carelli
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Programma di Neurogenetica, Bologna, Italy; Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy.
| | - Anna Maria Ghelli
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Programma di Neurogenetica, Bologna, Italy; Departments of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy.
| |
Collapse
|
4
|
Nagy-Grócz G, Spekker E, Vécsei L. Kynurenines, Neuronal Excitotoxicity, and Mitochondrial Oxidative Stress: Role of the Intestinal Flora. Int J Mol Sci 2024; 25:1698. [PMID: 38338981 PMCID: PMC10855176 DOI: 10.3390/ijms25031698] [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: 01/04/2024] [Revised: 01/26/2024] [Accepted: 01/29/2024] [Indexed: 02/12/2024] Open
Abstract
The intestinal flora has been the focus of numerous investigations recently, with inquiries not just into the gastrointestinal aspects but also the pathomechanism of other diseases such as nervous system disorders and mitochondrial diseases. Mitochondrial disorders are the most common type of inheritable metabolic illness caused by mutations of mitochondrial and nuclear DNA. Despite the intensive research, its diagnosis is usually difficult, and unfortunately, treating it challenges physicians. Metabolites of the kynurenine pathway are linked to many disorders, such as depression, schizophrenia, migraine, and also diseases associated with impaired mitochondrial function. The kynurenine pathway includes many substances, for instance kynurenic acid and quinolinic acid. In this review, we would like to show a possible link between the metabolites of the kynurenine pathway and mitochondrial stress in the context of intestinal flora. Furthermore, we summarize the possible markers of and future therapeutic options for the kynurenine pathway in excitotoxicity and mitochondrial oxidative stress.
Collapse
Affiliation(s)
- Gábor Nagy-Grócz
- Department of Neurology, Faculty of Medicine, Albert Szent-Györgyi Clinical Center, University of Szeged, Semmelweis u. 6, H-6725 Szeged, Hungary;
- Faculty of Health Sciences and Social Studies, University of Szeged, Temesvári krt. 31., H-6726 Szeged, Hungary
- Preventive Health Sciences Research Group, Incubation Competence Centre of the Centre of Excellence for Interdisciplinary Research, Development and Innovation of the University of Szeged, H-6720 Szeged, Hungary
| | | | - László Vécsei
- Department of Neurology, Faculty of Medicine, Albert Szent-Györgyi Clinical Center, University of Szeged, Semmelweis u. 6, H-6725 Szeged, Hungary;
- HUN-REN-SZTE Neuroscience Research Group, University of Szeged, Semmelweis u. 6, H-6725 Szeged, Hungary
| |
Collapse
|
5
|
Ma Q, Sun Y, Lei K, Luo W. Progress in diagnosis and treatment of Leber's hereditary optic neuropathy. J Mol Med (Berl) 2024; 102:1-10. [PMID: 37982904 DOI: 10.1007/s00109-023-02389-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 10/09/2023] [Accepted: 10/16/2023] [Indexed: 11/21/2023]
Abstract
Leber's hereditary optic neuropathy (LHON) is a mitochondrial genetic disease with central vision loss as the main symptom. It is one of the diseases that cause vision loss and optic atrophy in young and middle-aged people. The mutations of these three primary mitochondrial mutations, m.11778G>A, m.14484T>C, and m.3460G>A, are the main molecular basis, but their pathogenesis is also affected by nuclear genes, mitochondrial genetic background, and environmental factors. This article summarizes the research progress on molecular pathogenesis, clinical symptoms, and treatment of LHON in recent years, aiming to summarize the genetic pathogenesis and clinical treatment points of LHON.
Collapse
Affiliation(s)
- Qingyue Ma
- Department of Ophthalmology, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Ying Sun
- The Affiliated Qingdao Central Hospital of Qingdao University, The Second Affiliated Hospital of Medical College of Qingdao University, Qingdao, China
| | - Ke Lei
- Center of Tumor Immunology and Cytotherapy, Medical Research Center, The Affiliated Hospital of Qingdao University, Qingdao, China.
| | - Wenjuan Luo
- Department of Ophthalmology, The Affiliated Hospital of Qingdao University, Qingdao, China.
| |
Collapse
|
6
|
Hong S, Kim S, Kim K, Lee H. Clinical Approaches for Mitochondrial Diseases. Cells 2023; 12:2494. [PMID: 37887337 PMCID: PMC10605124 DOI: 10.3390/cells12202494] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 10/18/2023] [Accepted: 10/19/2023] [Indexed: 10/28/2023] Open
Abstract
Mitochondria are subcontractors dedicated to energy production within cells. In human mitochondria, almost all mitochondrial proteins originate from the nucleus, except for 13 subunit proteins that make up the crucial system required to perform 'oxidative phosphorylation (OX PHOS)', which are expressed by the mitochondria's self-contained DNA. Mitochondrial DNA (mtDNA) also encodes 2 rRNA and 22 tRNA species. Mitochondrial DNA replicates almost autonomously, independent of the nucleus, and its heredity follows a non-Mendelian pattern, exclusively passing from mother to children. Numerous studies have identified mtDNA mutation-related genetic diseases. The consequences of various types of mtDNA mutations, including insertions, deletions, and single base-pair mutations, are studied to reveal their relationship to mitochondrial diseases. Most mitochondrial diseases exhibit fatal symptoms, leading to ongoing therapeutic research with diverse approaches such as stimulating the defective OXPHOS system, mitochondrial replacement, and allotropic expression of defective enzymes. This review provides detailed information on two topics: (1) mitochondrial diseases caused by mtDNA mutations, and (2) the mechanisms of current treatments for mitochondrial diseases and clinical trials.
Collapse
Affiliation(s)
- Seongho Hong
- Korea Mouse Phenotyping Center, Seoul National University, Seoul 08826, Republic of Korea;
- Department of Medicine, Korea University College of Medicine, Seoul 02708, Republic of Korea
| | - Sanghun Kim
- Laboratory Animal Resource and Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju 28116, Republic of Korea;
- College of Veterinary Medicine and Research Institute of Veterinary Medicine, Chungbuk National University, Cheongju 28644, Republic of Korea
| | - Kyoungmi Kim
- Department of Biomedical Sciences, Korea University College of Medicine, Seoul 02841, Republic of Korea
- Department of Physiology, Korea University College of Medicine, Seoul 02841, Republic of Korea
| | - Hyunji Lee
- Department of Medicine, Korea University College of Medicine, Seoul 02708, Republic of Korea
| |
Collapse
|
7
|
Zaslavsky K, Donaldson L, Margolin E. Conversion to Leber Hereditary Optic Neuropathy After Hyperbaric Oxygen Therapy. J Neuroophthalmol 2023; 43:e70-e73. [PMID: 34629399 DOI: 10.1097/wno.0000000000001357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- Kirill Zaslavsky
- Department of Ophthalmology and Vision Sciences (KZ, LD, EM), University of Toronto, Toronto, Canada ; and Division of Neurology (EM), Department of Medicine, University of Toronto, Toronto, Canada
| | | | | |
Collapse
|
8
|
Smith AR, Hinojosa Briseño A, Picard M, Cardenas A. The prenatal environment and its influence on maternal and child mitochondrial DNA copy number and methylation: A review of the literature. ENVIRONMENTAL RESEARCH 2023; 227:115798. [PMID: 37001851 PMCID: PMC10164709 DOI: 10.1016/j.envres.2023.115798] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 03/13/2023] [Accepted: 03/28/2023] [Indexed: 05/08/2023]
Abstract
Mitochondrial DNA (mtDNA) is sensitive to environmental stressors and associated with human health. We reviewed epidemiological literature examining associations between prenatal environmental, dietary, and social exposures and alterations in maternal/child mtDNA copy number (mtDNAcn) and mtDNA methylation. Evidence exists that prenatal maternal exposures are associated with alterations in mtDNAcn for air pollution, chemicals (e.g. metals), cigarette smoke, human immunodeficiency virus (HIV) infection and treatment. Evidence for their associations with mtDNA methylation was limited. Given its potential implications as a disease pathway biomarker, studies with sufficient biological specificity should examine the long-term implications of prenatal and early-life mtDNA alterations in response to prenatal exposures.
Collapse
Affiliation(s)
- Anna R Smith
- Department of Epidemiology and Population Health, Stanford Medicine, Stanford, CA, USA
| | - Alejandra Hinojosa Briseño
- Department of Environmental and Occupational Health, California State University, Northridge, Northridge, CA, USA
| | - Martin Picard
- Department of Psychiatry, Division of Behavioral Medicine, Columbia University Irving Medical Center, New York City, New York, USA
| | - Andres Cardenas
- Department of Epidemiology and Population Health, Stanford Medicine, Stanford, CA, USA.
| |
Collapse
|
9
|
Wu H, Eckhardt CM, Baccarelli AA. Molecular mechanisms of environmental exposures and human disease. Nat Rev Genet 2023; 24:332-344. [PMID: 36717624 PMCID: PMC10562207 DOI: 10.1038/s41576-022-00569-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/14/2022] [Indexed: 02/01/2023]
Abstract
A substantial proportion of disease risk for common complex disorders is attributable to environmental exposures and pollutants. An appreciation of how environmental pollutants act on our cells to produce deleterious health effects has led to advances in our understanding of the molecular mechanisms underlying the pathogenesis of chronic diseases, including cancer and cardiovascular, neurodegenerative and respiratory diseases. Here, we discuss emerging research on the interplay of environmental pollutants with the human genome and epigenome. We review evidence showing the environmental impact on gene expression through epigenetic modifications, including DNA methylation, histone modification and non-coding RNAs. We also highlight recent studies that evaluate recently discovered molecular processes through which the environment can exert its effects, including extracellular vesicles, the epitranscriptome and the mitochondrial genome. Finally, we discuss current challenges when studying the exposome - the cumulative measure of environmental influences over the lifespan - and its integration into future environmental health research.
Collapse
Affiliation(s)
- Haotian Wu
- Department of Environmental Health Sciences, Columbia University Mailman School of Public Health, New York, NY, USA
| | - Christina M Eckhardt
- Department of Pulmonary, Allergy and Critical Care Medicine, Columbia University College of Physicians and Surgeons, New York, NY, USA
| | - Andrea A Baccarelli
- Department of Environmental Health Sciences, Columbia University Mailman School of Public Health, New York, NY, USA.
| |
Collapse
|
10
|
Kupsco A, Bloomquist TR, Hu H, Reddam A, Tang D, Goldsmith J, Rundle AG, Baccarelli AA, Herbstman JB. Mitochondrial DNA copy number dynamics and associations with the prenatal environment from birth through adolescence in a population of Dominican and African American children. Mitochondrion 2023; 69:140-146. [PMID: 36804466 PMCID: PMC10006332 DOI: 10.1016/j.mito.2023.02.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 01/17/2023] [Accepted: 02/13/2023] [Indexed: 02/18/2023]
Abstract
Mitochondrial DNA copy number (mtDNAcn) dynamics throughout childhood are poorly understood. We profiled mtDNAcn from birth through adolescence and evaluated how the prenatal environment influences mtDNAcn across childhood. Data were collected from children from New York City followed through 18 years. Using duplexed qRT-PCR, we quantified mtDNAcn relative to nuclear DNA in blood collected from the umbilical cord (n = 450), children aged 5-7 (n = 510), and adolescents aged 15-18 (n = 278). We examined mtDNAcn across childhood with linear mixed-effects models (LMM). Relative mtDNAcn was lowest at birth (mean ± SD: 0.67 ± 0.35) and increased in childhood (1.24 ± 0.50) then slightly declined in adolescence (1.13 ± 0.44). We observed no differences in mtDNAcn by sex or race/ethnicity. mtDNAcn was positively associated with prenatal environmental tobacco smoke exposure (0.077 [ 0.01, 0.14] change in relative mtDNAcn) but negatively associated with maternal completion of high school (-0.066 [-0.13, 0.00]), with the receipt of public assistance at birth (-0.074 [-0.14, -0.01]), and when mother born outside the U.S (-0.061 [-0.13, 0.003]). Infant birth outcomes were not associated with mtDNAcn. MtDNAcn levels were dynamic through childhood and associated with some prenatal factors, underscoring the need for the investigation of longitudinal mtDNAcn for human health research.
Collapse
Affiliation(s)
- Allison Kupsco
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY, United States.
| | - Tessa R Bloomquist
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY, United States
| | - Heng Hu
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY, United States
| | - Aalekhya Reddam
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY, United States
| | - Deliang Tang
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY, United States
| | - Jeff Goldsmith
- Department of Biostatistics, Mailman School of Public Health, Columbia University, New York, NY, United States
| | - Andrew G Rundle
- Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, NY, United States
| | - Andrea A Baccarelli
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY, United States
| | - Julie B Herbstman
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY, United States
| |
Collapse
|
11
|
Kornblum C, Lamperti C, Parikh S. Currently available therapies in mitochondrial disease. HANDBOOK OF CLINICAL NEUROLOGY 2023; 194:189-206. [PMID: 36813313 DOI: 10.1016/b978-0-12-821751-1.00007-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
Mitochondrial diseases are a heterogeneous group of multisystem disorders caused by impaired mitochondrial function. These disorders occur at any age and involve any tissue, typically affecting organs highly dependent on aerobic metabolism. Diagnosis and management are extremely difficult due to various underlying genetic defects and a wide range of clinical symptoms. Preventive care and active surveillance are strategies to try to reduce morbidity and mortality by timely treatment of organ-specific complications. More specific interventional therapies are in early phases of development and no effective treatment or cure currently exists. A variety of dietary supplements have been utilized based on biological logic. For several reasons, few randomized controlled trials have been completed to assess the efficacy of these supplements. The majority of the literature on supplement efficacy represents case reports, retrospective analyses and open-label studies. We briefly review selected supplements that have some degree of clinical research support. In mitochondrial diseases, potential triggers of metabolic decompensation or medications that are potentially toxic to mitochondrial function should be avoided. We shortly summarize current recommendations on safe medication in mitochondrial diseases. Finally, we focus on the frequent and debilitating symptoms of exercise intolerance and fatigue and their management including physical training strategies.
Collapse
Affiliation(s)
- Cornelia Kornblum
- Department of Neurology, Neuromuscular Disease Section, University Hospital Bonn, Bonn, Germany.
| | - Costanza Lamperti
- Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Sumit Parikh
- Center for Pediatric Neurosciences, Mitochondrial Medicine & Neurogenetics, Cleveland Clinic, Cleveland, OH, United States
| |
Collapse
|
12
|
Abstract
Mitochondrial optic neuropathies have a leading role in the field of mitochondrial medicine ever since 1988, when the first mutation in mitochondrial DNA was associated with Leber's hereditary optic neuropathy (LHON). Autosomal dominant optic atrophy (DOA) was subsequently associated in 2000 with mutations in the nuclear DNA affecting the OPA1 gene. LHON and DOA are both characterized by selective neurodegeneration of retinal ganglion cells (RGCs) triggered by mitochondrial dysfunction. This is centered on respiratory complex I impairment in LHON and defective mitochondrial dynamics in OPA1-related DOA, leading to distinct clinical phenotypes. LHON is a subacute, rapid, severe loss of central vision involving both eyes within weeks or months, with age of onset between 15 and 35 years old. DOA is a more slowly progressive optic neuropathy, usually apparent in early childhood. LHON is characterized by marked incomplete penetrance and a clear male predilection. The introduction of next-generation sequencing has greatly expanded the genetic causes for other rare forms of mitochondrial optic neuropathies, including recessive and X-linked, further emphasizing the exquisite sensitivity of RGCs to compromised mitochondrial function. All forms of mitochondrial optic neuropathies, including LHON and DOA, can manifest either as pure optic atrophy or as a more severe multisystemic syndrome. Mitochondrial optic neuropathies are currently at the forefront of a number of therapeutic programs, including gene therapy, with idebenone being the only approved drug for a mitochondrial disorder.
Collapse
Affiliation(s)
- Valerio Carelli
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy; IRCCS Istituto di Scienze Neurologiche di Bologna, Programma di Neurogenetica, Bologna, Italy.
| | - Chiara La Morgia
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy; IRCCS Istituto di Scienze Neurologiche di Bologna, Programma di Neurogenetica, Bologna, Italy
| | - Patrick Yu-Wai-Man
- John van Geest Centre for Brain Repair and MRC Mitochondrial Biology Unit, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom; Cambridge Eye Unit, Addenbrooke's Hospital, Cambridge University Hospitals, Cambridge, United Kingdom; Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom; Institute of Ophthalmology, University College London, London, United Kingdom
| |
Collapse
|
13
|
Wang H, Fu M, Ma Y, Liu C, Wu M, Nie J. Tobacco smoke exposure and mitochondrial DNA copy number on neurobehavioural performance: A community study. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:84180-84190. [PMID: 35776305 DOI: 10.1007/s11356-022-20921-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 05/13/2022] [Indexed: 06/15/2023]
Abstract
The influence of tobacco smoke has been a controversial and very questionable subject within the field of neurological behaviours. To examine the dose-response relationships between tobacco smoke and neurological performance, we investigated whether mitochondrial DNA copy number (mtDNAcn) mediates these relationships. We used restricted cubic spline models to estimate the dose-response relationships. A mediation model was also used to detect the mediating effect. Increased cotinine was negatively associated with auditory memory scores and a 0.51 decrease in mtDNAcn. MtDNAcn acts as a mediator between cotinine and auditory memory. Tobacco smoke levels were inversely associated with mtDNAcn and neurobehavioural changes, and there was a mediation effect between cotinine levels and auditory memory by mtDNAcn.
Collapse
Affiliation(s)
- Huimin Wang
- Department of Occupational Health, School of Public Health, Shanxi Medical University, Taiyuan, 030001, Shanxi, China
| | - Mengmeng Fu
- Department of Occupational Health, School of Public Health, Shanxi Medical University, Taiyuan, 030001, Shanxi, China
| | - Yifei Ma
- Department of Occupational Health, School of Public Health, Shanxi Medical University, Taiyuan, 030001, Shanxi, China
| | - Chenjuan Liu
- Department of Occupational Health, School of Public Health, Shanxi Medical University, Taiyuan, 030001, Shanxi, China
| | - Min Wu
- Department of Occupational Health, School of Public Health, Shanxi Medical University, Taiyuan, 030001, Shanxi, China
| | - Jisheng Nie
- Department of Occupational Health, School of Public Health, Shanxi Medical University, Taiyuan, 030001, Shanxi, China.
| |
Collapse
|
14
|
Spiegel SJ, Sadun AA. Solutions to a Radical Problem: Overview of Current and Future Treatment Strategies in Leber's Hereditary Opic Neuropathy. Int J Mol Sci 2022; 23:13205. [PMID: 36361994 PMCID: PMC9656544 DOI: 10.3390/ijms232113205] [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: 09/27/2022] [Revised: 10/24/2022] [Accepted: 10/26/2022] [Indexed: 09/23/2023] Open
Abstract
Leber's Hereditary Optic Neuropathy (LHON) is the most common primary mitochondrial DNA disorder. It is characterized by bilateral severe central subacute vision loss due to specific loss of Retinal Ganglion Cells and their axons. Historically, treatment options have been quite limited, but ongoing clinical trials show promise, with significant advances being made in the testing of free radical scavengers and gene therapy. In this review, we summarize management strategies and rational of treatment based on current insights from molecular research. This includes preventative recommendations for unaffected genetic carriers, current medical and supportive treatments for those affected, and emerging evidence for future potential therapeutics.
Collapse
Affiliation(s)
- Samuel J. Spiegel
- Gavin Herbert Eye Institute, University of California, Irvine, CA 92617, USA
| | - Alfredo A. Sadun
- Jules Stein and Doheny Eye Institute, University of California, Los Angeles, CA 90095, USA
| |
Collapse
|
15
|
Lambiri DW, Levin LA. Modeling Reactive Oxygen Species-Induced Axonal Loss in Leber Hereditary Optic Neuropathy. Biomolecules 2022; 12:biom12101411. [PMID: 36291620 PMCID: PMC9599876 DOI: 10.3390/biom12101411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 09/29/2022] [Accepted: 09/30/2022] [Indexed: 11/17/2022] Open
Abstract
Leber hereditary optic neuropathy (LHON) is a rare syndrome that results in vision loss. A necessary but not sufficient condition for its onset is the existence of known mitochondrial DNA mutations that affect complex I biomolecular structure. Cybrids with LHON mutations generate higher rates of reactive oxygen species (ROS). This study models how ROS, particularly H2O2, could signal and execute the axonal degeneration process that underlies LHON. We modeled and explored several hypotheses regarding the influence of H2O2 on the dynamics of propagation of axonal degeneration in LHON. Zonal oxidative stress, corresponding to H2O2 gradients, correlated with the morphology of injury exhibited in the LHON pathology. If the axonal membrane is highly permeable to H2O2 and oxidative stress induces larger production of H2O2, small injuries could trigger cascading failures of neighboring axons. The cellular interdependence created by H2O2 diffusion, and the gradients created by tissue variations in H2O2 production and scavenging, result in injury patterns and surviving axonal loss distributions similar to LHON tissue samples. Specifically, axonal degeneration starts in the temporal optic nerve, where larger groups of small diameter fibers are located and propagates from that region. These findings correlate well with clinical observations of central loss of visual field, visual acuity, and color vision in LHON, and may serve as an in silico platform for modeling the mechanism of action for new therapeutics.
Collapse
Affiliation(s)
- Darius W. Lambiri
- Department of Physiology, McGill University, Montreal, QC H3G 1Y6, Canada
| | - Leonard A. Levin
- Department of Ophthalmology and Visual Sciences, McGill University, Montreal, QC H4A 3S5, Canada
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC H3A 2B4, Canada
- Correspondence:
| |
Collapse
|
16
|
Pathological mitophagy disrupts mitochondrial homeostasis in Leber's hereditary optic neuropathy. Cell Rep 2022; 40:111124. [PMID: 35858578 PMCID: PMC9314546 DOI: 10.1016/j.celrep.2022.111124] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 03/27/2022] [Accepted: 06/29/2022] [Indexed: 01/18/2023] Open
Abstract
Leber’s hereditary optic neuropathy (LHON), a disease associated with a mitochondrial DNA mutation, is characterized by blindness due to degeneration of retinal ganglion cells (RGCs) and their axons, which form the optic nerve. We show that a sustained pathological autophagy and compartment-specific mitophagy activity affects LHON patient-derived cells and cybrids, as well as induced pluripotent-stem-cell-derived neurons. This is variably counterbalanced by compensatory mitobiogenesis. The aberrant quality control disrupts mitochondrial homeostasis as reflected by defective bioenergetics and excessive reactive oxygen species production, a stress phenotype that ultimately challenges cell viability by increasing the rate of apoptosis. We counteract this pathological mechanism by using autophagy regulators (clozapine and chloroquine) and redox modulators (idebenone), as well as genetically activating mitochondrial biogenesis (PGC1-α overexpression). This study substantially advances our understanding of LHON pathophysiology, providing an integrated paradigm for pathogenesis of mitochondrial diseases and druggable targets for therapy. Autophagy and mitophagy are abnormally activated in samples carrying LHON mutations Autophagy and mitophagy affect LHON cells’ viability Therapeutic approaches targeting autophagy reverts LHON cells’ apoptotic death
Collapse
|
17
|
Vela-Sebastián A, López-Gallardo E, Emperador S, Hernández-Ainsa C, Pacheu-Grau D, Blanco I, Ros A, Pascual-Benito E, Rabaneda-Lombarte N, Presas-Rodríguez S, García-Robles P, Montoya J, Ruiz-Pesini E. Toxic and nutritional factors trigger leber hereditary optic neuropathy due to a mitochondrial tRNA mutation. Clin Genet 2022; 102:339-344. [PMID: 35808913 PMCID: PMC9543827 DOI: 10.1111/cge.14189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 06/20/2022] [Accepted: 07/05/2022] [Indexed: 12/04/2022]
Abstract
Leber hereditary optic neuropathy is a mitochondrial disease mainly due to pathologic mutations in mitochondrial genes related to the respiratory complex I of the oxidative phosphorylation system. Genetic, physiological, and environmental factors modulate the penetrance of these mutations. We report two patients suffering from this disease and harboring a m.15950G > A mutation in the mitochondrial DNA‐encoded gene for the threonine transfer RNA. We also provide evidences supporting the pathogenicity of this mutation.
Collapse
Affiliation(s)
- Ana Vela-Sebastián
- Departamento de Bioquímica, Biología Molecular y Celular. Universidad de Zaragoza, Zaragoza, Spain
| | - Ester López-Gallardo
- Departamento de Bioquímica, Biología Molecular y Celular. Universidad de Zaragoza, Zaragoza, Spain.,Instituto de Investigación Sanitaria (IIS) de Aragón, Zaragoza, Spain.,Centro de Investigaciones Biomédicas en Red de Enfermedades Raras (CIBERER), Madrid, Spain
| | - Sonia Emperador
- Departamento de Bioquímica, Biología Molecular y Celular. Universidad de Zaragoza, Zaragoza, Spain.,Instituto de Investigación Sanitaria (IIS) de Aragón, Zaragoza, Spain.,Centro de Investigaciones Biomédicas en Red de Enfermedades Raras (CIBERER), Madrid, Spain
| | - Carmen Hernández-Ainsa
- Departamento de Bioquímica, Biología Molecular y Celular. Universidad de Zaragoza, Zaragoza, Spain.,Instituto de Investigación Sanitaria (IIS) de Aragón, Zaragoza, Spain.,Centro de Investigaciones Biomédicas en Red de Enfermedades Raras (CIBERER), Madrid, Spain
| | - David Pacheu-Grau
- Departamento de Bioquímica, Biología Molecular y Celular. Universidad de Zaragoza, Zaragoza, Spain.,Instituto de Investigación Sanitaria (IIS) de Aragón, Zaragoza, Spain.,Centro de Investigaciones Biomédicas en Red de Enfermedades Raras (CIBERER), Madrid, Spain
| | | | | | | | - Neus Rabaneda-Lombarte
- Departamento de Neurociencias, Hospital Universitari Germans Trias i Pujol, Badalona, Spain
| | | | - Pilar García-Robles
- Servicio de Oftalmología. Hospital Universitario Virgen de las Nieves, Granada, Spain
| | - Julio Montoya
- Departamento de Bioquímica, Biología Molecular y Celular. Universidad de Zaragoza, Zaragoza, Spain.,Instituto de Investigación Sanitaria (IIS) de Aragón, Zaragoza, Spain.,Centro de Investigaciones Biomédicas en Red de Enfermedades Raras (CIBERER), Madrid, Spain
| | - Eduardo Ruiz-Pesini
- Departamento de Bioquímica, Biología Molecular y Celular. Universidad de Zaragoza, Zaragoza, Spain.,Instituto de Investigación Sanitaria (IIS) de Aragón, Zaragoza, Spain.,Centro de Investigaciones Biomédicas en Red de Enfermedades Raras (CIBERER), Madrid, Spain
| |
Collapse
|
18
|
A Tale of Progressive Painless Vision Loss in a 64-Year-Old Man Due to Leber Hereditary Optic Neuropathy. J Neuroophthalmol 2022; 42:390-395. [DOI: 10.1097/wno.0000000000001651] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
19
|
Thomas RH, Hunter A, Butterworth L, Feeney C, Graves TD, Holmes S, Hossain P, Lowndes J, Sharpe J, Upadhyaya S, Varhaug KN, Votruba M, Wheeler R, Staley K, Rahman S. Research priorities for mitochondrial disorders: Current landscape and patient and professional views. J Inherit Metab Dis 2022; 45:796-803. [PMID: 35543492 PMCID: PMC9429991 DOI: 10.1002/jimd.12521] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 04/16/2022] [Accepted: 04/27/2022] [Indexed: 11/15/2022]
Abstract
Primary mitochondrial disorders encompass a wide range of clinical presentations and a spectrum of severity. They currently lack effective disease-modifying therapies and have a high mortality and morbidity rate. It is therefore essential to know that competitively funded research designed by academics meets the core needs of people with mitochondrial disorders and their clinicians. Priority setting partnerships are an established collaborative methodology that brings patients, carers and families, charity representatives and clinicians together to try to establish the most pressing and unanswered research priorities for a particular disease. We developed a web-based questionnaire, requesting all patients affected by primary mitochondrial disease, their carers and clinicians to pose their research questions. This yielded 709 questions from 147 participants. These were grouped into overarching themes including basic biology, causation, health services, clinical management, social impacts, prognosis, prevention, symptoms, treatment and psychological impact. Following the removal of "answered questions", the process resulted in a list of 42 discrete, answerable questions. This was further refined by web-based ranking by the community to 24 questions. These were debated at a face-to-face workshop attended by a diverse range of patients, carers, charity representatives and clinicians to create a definitive "Top 10 of unanswered research questions for primary mitochondrial disorders". These Top 10 questions related to understanding biological processes, including triggers of disease onset, mechanisms underlying progression and reasons for differential symptoms between individuals with identical genetic mutations; new treatments; biomarker discovery; psychological support and optimal management of stroke-like episodes and fatigue.
Collapse
Affiliation(s)
- Rhys H. Thomas
- Translational and Clinical Research InstituteNewcastle UniversityNewcastleUK
| | | | | | - Catherine Feeney
- NHS Highly Specialised Service for Rare Mitochondrial Diseases, Newcastle Hospitals NHS Foundation TrustNewcastleUK
| | - Tracey D. Graves
- Hinchingbrooke HospitalHuntingdonUK
- The National Hospital for Neurology and NeurosurgeryLondonUK
| | - Sarah Holmes
- The National Hospital for Neurology and NeurosurgeryLondonUK
| | | | - Jo Lowndes
- Oxford University Hospitals NHS Foundation TrustOxfordUK
| | - Jenny Sharpe
- Centre for Innovation in Regulatory ScienceLondonUK
| | | | - Kristin N. Varhaug
- Translational and Clinical Research InstituteNewcastle UniversityNewcastleUK
| | - Marcela Votruba
- University Hospital Wales and School of Vision SciencesCardiff UniversityCardiffUK
| | | | | | - Shamima Rahman
- Mitochondrial Research Group, UCL Great Ormond Street Institute of Child Health and Great Ormond Street Hospital for Children NHS Foundation TrustLondonUK
| |
Collapse
|
20
|
Wang X, Memon AA, Palmér K, Hedelius A, Sundquist J, Sundquist K. The association of mitochondrial DNA copy number with incident mental disorders in women: A population-based follow-up study. J Affect Disord 2022; 308:111-115. [PMID: 35427715 DOI: 10.1016/j.jad.2022.04.064] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 01/21/2022] [Accepted: 04/10/2022] [Indexed: 01/01/2023]
Abstract
BACKGROUND Available evidence suggests that mitochondrial DNA copy number (mtDNA-CN) may differ among patients with mental disorders compared to the general population. However, whether mtDNA-CN is independently associated with the subsequent incidence of mental disorders remains unclear. MATERIAL AND METHODS We used droplet digital PCR to measure the absolute mtDNA-CN in DNA samples obtained from a population-based follow-up study, which included a total of 2354 middle-aged women (52-63 years) who were free of mental disorders at baseline. After 17 years (median) of follow-up, 727 participants were diagnosed with mental disorders. RESULTS In the univariate Cox regression, lower baseline mtDNA-CN (mtDNA-CN < 117) was associated with a higher risk of mental disorders (HR = 1.16, p = 0.047). In addition, smoking, marital status and sleeping quality were associated with both mtDNA-CN and mental disorders. After adjusting for these variables, the association between mtDNA-CN and mental disorders decreased and became non-significant (HR = 1.07, p = 0.36). Stratification of data according to the subtype of mental disorders, showed that low mtDNA-CN was associated with a higher risk of alcohol or drug use disorders (HR = 1.82, p = 0.045 after adjusting). CONCLUSION In the present study, we could not find any independent association between mtDNA-CN blood and the most common mental disorders in a population-based follow-up study of Swedish women, except for alcohol and drug use disorders. The use of blood mtDNA-CN as a biomarker of mental disorders, in addition to other risk factors, needs to be further examined in future studies.
Collapse
Affiliation(s)
- Xiao Wang
- Center for Primary Health Care Research, Lund University/Region Skåne, Malmö 20502, Sweden.
| | - Ashfaque A Memon
- Center for Primary Health Care Research, Lund University/Region Skåne, Malmö 20502, Sweden
| | - Karolina Palmér
- Center for Primary Health Care Research, Lund University/Region Skåne, Malmö 20502, Sweden
| | - Anna Hedelius
- Center for Primary Health Care Research, Lund University/Region Skåne, Malmö 20502, Sweden
| | - Jan Sundquist
- Center for Primary Health Care Research, Lund University/Region Skåne, Malmö 20502, Sweden; Department of Family Medicine and Community Health, Department of Population Health Science and Policy Icahn School of Medicine at Mount Sinai, New York, USA; Center for Community-based Healthcare Research and Education (CoHRE), Department of Functional Pathology, School of Medicine, Shimane University, Japan
| | - Kristina Sundquist
- Center for Primary Health Care Research, Lund University/Region Skåne, Malmö 20502, Sweden; Department of Family Medicine and Community Health, Department of Population Health Science and Policy Icahn School of Medicine at Mount Sinai, New York, USA; Center for Community-based Healthcare Research and Education (CoHRE), Department of Functional Pathology, School of Medicine, Shimane University, Japan
| |
Collapse
|
21
|
Targeting the alternative oxidase (AOX) for human health and food security, a pharmaceutical and agrochemical target or a rescue mechanism? Biochem J 2022; 479:1337-1359. [PMID: 35748702 PMCID: PMC9246349 DOI: 10.1042/bcj20180192] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 05/23/2022] [Accepted: 06/07/2022] [Indexed: 11/25/2022]
Abstract
Some of the most threatening human diseases are due to a blockage of the mitochondrial electron transport chain (ETC). In a variety of plants, fungi, and prokaryotes, there is a naturally evolved mechanism for such threats to viability, namely a bypassing of the blocked portion of the ETC by alternative enzymes of the respiratory chain. One such enzyme is the alternative oxidase (AOX). When AOX is expressed, it enables its host to survive life-threatening conditions or, as in parasites, to evade host defenses. In vertebrates, this mechanism has been lost during evolution. However, we and others have shown that transfer of AOX into the genome of the fruit fly and mouse results in a catalytically engaged AOX. This implies that not only is the AOX a promising target for combating human or agricultural pathogens but also a novel approach to elucidate disease mechanisms or, in several cases, potentially a therapeutic cure for human diseases. In this review, we highlight the varying functions of AOX in their natural hosts and upon xenotopic expression, and discuss the resulting need to develop species-specific AOX inhibitors.
Collapse
|
22
|
Avilés-Ramírez C, Moreno-Godínez ME, Bonner MR, Parra-Rojas I, Flores-Alfaro E, Ramírez M, Huerta-Beristain G, Ramírez-Vargas MA. Effects of exposure to environmental pollutants on mitochondrial DNA copy number: a meta-analysis. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:43588-43606. [PMID: 35399130 DOI: 10.1007/s11356-022-19967-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 03/25/2022] [Indexed: 06/14/2023]
Abstract
Exposure to environmental pollutants has been associated with alteration on relative levels of mitochondrial DNA copy number (mtDNAcn). However, the results obtained from epidemiological studies are inconsistent. This meta-analysis aimed to evaluate whether environmental pollutant exposure can modify the relative levels of mtDNAcn in humans. We performed a literature search using PubMed, Scopus, and Web of Science databases. We selected and reviewed original articles performed in humans that analyzed the relationship between environmental pollutant exposure and the relative levels of mtDNAcn; the selection of the included studies was based on inclusion and exclusion criteria. Only twenty-two studies fulfilled our inclusion criteria. A total of 6011 study participants were included in this systematic review and meta-analysis. We grouped the included studies into four main categories according to the type of environmental pollutant: (1) heavy metals, (2) polycyclic aromatic hydrocarbons (PAHs), (3) particulate matter (PM), and (4) cigarette smoking. Inconclusive results were observed in all categories; the pooled analysis shows a marginal increase of relative levels of mtDNAcn in response to environmental pollutant exposure. The trial sequential analysis and rate confidence in body evidence showed the need to perform new studies. Therefore, a large-scale cohort and mechanistic studies in this area are required to probe the possible use of relative levels of mtDNAcn as biomarkers linked to environmental pollution exposure.
Collapse
Affiliation(s)
- Cristian Avilés-Ramírez
- Facultad de Ciencias Químico-Biológicas, Laboratorio de Toxicología Y Salud Ambiental, Universidad Autónoma De Guerrero, Av. Lázaro Cárdenas s/n, 39089, Chilpancingo, GRO, México
| | - Ma Elena Moreno-Godínez
- Facultad de Ciencias Químico-Biológicas, Laboratorio de Toxicología Y Salud Ambiental, Universidad Autónoma De Guerrero, Av. Lázaro Cárdenas s/n, 39089, Chilpancingo, GRO, México
| | - Matthew R Bonner
- Department of Epidemiology and Environmental Health, School of Public Health and Health Professions, University at Buffalo, Buffalo, NY, USA
| | - Isela Parra-Rojas
- Facultad de Ciencias Químico-Biológicas, Laboratorio de Investigación en Obesidad Y Diabetes, Universidad Autónoma de Guerrero, Chilpancingo, Guerrero, México
| | - Eugenia Flores-Alfaro
- Facultad de Ciencias Químico-Biológicas, Laboratorio de Epidemiología Clínica Y Molecular, Universidad Autónoma de Guerrero, Chilpancingo, Guerrero, México
| | - Mónica Ramírez
- Facultad de Ciencias Químico-Biológicas, CONACyT, Universidad Autónoma de Guerrero, Chilpancingo, Guerrero, México
| | - Gerardo Huerta-Beristain
- Facultad de Ciencias Químico-Biológicas, Laboratorio de Toxicología Y Salud Ambiental, Universidad Autónoma De Guerrero, Av. Lázaro Cárdenas s/n, 39089, Chilpancingo, GRO, México
| | - Marco Antonio Ramírez-Vargas
- Facultad de Ciencias Químico-Biológicas, Laboratorio de Toxicología Y Salud Ambiental, Universidad Autónoma De Guerrero, Av. Lázaro Cárdenas s/n, 39089, Chilpancingo, GRO, México.
| |
Collapse
|
23
|
Pfeffer G, Lee G, Pontifex CS, Fanganiello RD, Peck A, Weihl CC, Kimonis V. Multisystem Proteinopathy Due to VCP Mutations: A Review of Clinical Heterogeneity and Genetic Diagnosis. Genes (Basel) 2022; 13:genes13060963. [PMID: 35741724 PMCID: PMC9222868 DOI: 10.3390/genes13060963] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 05/24/2022] [Accepted: 05/24/2022] [Indexed: 02/06/2023] Open
Abstract
In this work, we review clinical features and genetic diagnosis of diseases caused by mutations in the gene encoding valosin-containing protein (VCP/p97), the functionally diverse AAA-ATPase. VCP is crucial to a multitude of cellular functions including protein quality control, stress granule formation and clearance, and genomic integrity functions, among others. Pathogenic mutations in VCP cause multisystem proteinopathy (VCP-MSP), an autosomal dominant, adult-onset disorder causing dysfunction in several tissue types. It can result in complex neurodegenerative conditions including inclusion body myopathy, frontotemporal dementia, amyotrophic lateral sclerosis, or combinations of these. There is also an association with other neurodegenerative phenotypes such as Alzheimer-type dementia and Parkinsonism. Non-neurological presentations include Paget disease of bone and may also include cardiac dysfunction. We provide a detailed discussion of genotype-phenotype correlations, recommendations for genetic diagnosis, and genetic counselling implications of VCP-MSP.
Collapse
Affiliation(s)
- Gerald Pfeffer
- Hotchkiss Brain Institute, Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada;
- Alberta Child Health Research Institute, Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
- Correspondence:
| | - Grace Lee
- Division of Genetic and Genomic Medicine, Department of Pediatrics, University of California Irvine Medical Center, Orange, CA 92868, USA; (G.L.); (V.K.)
| | - Carly S. Pontifex
- Hotchkiss Brain Institute, Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada;
| | - Roberto D. Fanganiello
- Oral Ecology Research Group, Faculty of Dental Medicine, Université Laval, Quebec City, QC G1V 0A6, Canada;
| | - Allison Peck
- Cure VCP Disease, Inc., Americus, GA 31709, USA;
| | - Conrad C. Weihl
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA;
| | - Virginia Kimonis
- Division of Genetic and Genomic Medicine, Department of Pediatrics, University of California Irvine Medical Center, Orange, CA 92868, USA; (G.L.); (V.K.)
| |
Collapse
|
24
|
Yang YP, Chang YL, Lai YH, Tsai PH, Hsiao YJ, Nguyen LH, Lim XZ, Weng CC, Ko YL, Yang CH, Hwang DK, Chen SJ, Chiou SH, Chiou GY, Wang AG, Chien Y. Retinal Circular RNA hsa_circ_0087207 Expression Promotes Apoptotic Cell Death in Induced Pluripotent Stem Cell-Derived Leber’s Hereditary Optic Neuropathy-like Models. Biomedicines 2022; 10:biomedicines10040788. [PMID: 35453537 PMCID: PMC9027941 DOI: 10.3390/biomedicines10040788] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Revised: 03/22/2022] [Accepted: 03/24/2022] [Indexed: 02/01/2023] Open
Abstract
Backgrounds: Leber’s hereditary optic neuropathy (LHON) is known as an inherited retinal disorder characterized by the bilateral central vision loss and degeneration of retinal ganglion cells (RGCs). Unaffected LHON carriers are generally asymptomatic, suggesting that certain factors may contribute to the disease manifestations between carriers and patients who carry the same mutated genotypes. Methods: We first aimed to establish the iPSC-differentiated RGCs from the normal healthy subject, the carrier, and the LHON patient and then compared the differential expression profile of circular RNAs (CircRNAs) among RGCs from these donors in vitro. We further overexpressed or knocked down the most upregulated circRNA to examine whether this circRNA contributes to the distinct phenotypic manifestations between the carrier- and patient-derived RGCs. Results: iPSCs were generated from the peripheral blood cells from the healthy subject, the carrier, and the LHON patient and successfully differentiated into RGCs. These RGCs carried equivalent intracellular reactive oxygen species, but only LHON-patient iPSC-derived RGCs exhibited remarkable apoptosis. Next-generation sequencing and quantitative real-time PCR revealed the circRNA hsa_circ_0087207 as the most upregulated circRNA in LHON-patient iPSC-derived RGCs. Overexpression of hsa_circ_0087207 increased the apoptosis in carrier iPSC-derived RGCs, while knockdown of hsa_circ_0087207 attenuated the apoptosis in LHON-patient iPSC-derived RGCs. Predicted by bioinformatics approaches, hsa_circ_0087207 acts as the sponge of miR-665 to induce the expression of a variety of apoptosis-related genes in LHON patient iPSC-derived RGCs. Conclusions: Our data indicated that hsa_circ_0087207 upregulation distinguishes the disease phenotype manifestations between iPSC-derived RGCs generated from the LHON patient and carrier. Targeting the hsa_circ_0087207/miR-665 axis might hold therapeutic promises for the treatment of LHON.
Collapse
Affiliation(s)
- Yi-Ping Yang
- Department of Medical Research, Taipei Veteran General Hospital, Taipei 11217, Taiwan; (Y.-P.Y.); (Y.-H.L.); (P.-H.T.); (Y.-J.H.); (L.H.N.); (X.-Z.L.); (Y.-L.K.); (S.-H.C.)
- Institute of Food Safety and Health Risk Assessment, School of Pharmaceutical Sciences, National Yang Ming Chiao Tung University, Taipei 11217, Taiwan
- School of Medicine, National Yang-Ming Chiao Tung University, Taipei 11217, Taiwan; (D.-K.H.); (S.-J.C.); (A.-G.W.)
| | - Yuh-Lih Chang
- Department of Pharmacy, Taipei Veterans General Hospital, Taipei 11217, Taiwan;
- Department of Pharmacy, National Yang Ming Chiao Tung University, Taipei 11217, Taiwan
| | - Yun-Hsien Lai
- Department of Medical Research, Taipei Veteran General Hospital, Taipei 11217, Taiwan; (Y.-P.Y.); (Y.-H.L.); (P.-H.T.); (Y.-J.H.); (L.H.N.); (X.-Z.L.); (Y.-L.K.); (S.-H.C.)
- Institute of Pharmacology, College of Medicine, National Yang Ming Chiao Tung University, Taipei 11217, Taiwan
| | - Ping-Hsing Tsai
- Department of Medical Research, Taipei Veteran General Hospital, Taipei 11217, Taiwan; (Y.-P.Y.); (Y.-H.L.); (P.-H.T.); (Y.-J.H.); (L.H.N.); (X.-Z.L.); (Y.-L.K.); (S.-H.C.)
- Institute of Pharmacology, College of Medicine, National Yang Ming Chiao Tung University, Taipei 11217, Taiwan
| | - Yu-Jer Hsiao
- Department of Medical Research, Taipei Veteran General Hospital, Taipei 11217, Taiwan; (Y.-P.Y.); (Y.-H.L.); (P.-H.T.); (Y.-J.H.); (L.H.N.); (X.-Z.L.); (Y.-L.K.); (S.-H.C.)
- School of Medicine, National Yang-Ming Chiao Tung University, Taipei 11217, Taiwan; (D.-K.H.); (S.-J.C.); (A.-G.W.)
| | - Long Hoang Nguyen
- Department of Medical Research, Taipei Veteran General Hospital, Taipei 11217, Taiwan; (Y.-P.Y.); (Y.-H.L.); (P.-H.T.); (Y.-J.H.); (L.H.N.); (X.-Z.L.); (Y.-L.K.); (S.-H.C.)
- Institute of Pharmacology, College of Medicine, National Yang Ming Chiao Tung University, Taipei 11217, Taiwan
- Department of Basic Medical Sciences, Hanoi University of Pharmacy, Hanoi 100000, Vietnam
| | - Xue-Zhen Lim
- Department of Medical Research, Taipei Veteran General Hospital, Taipei 11217, Taiwan; (Y.-P.Y.); (Y.-H.L.); (P.-H.T.); (Y.-J.H.); (L.H.N.); (X.-Z.L.); (Y.-L.K.); (S.-H.C.)
- Institute of Pharmacology, College of Medicine, National Yang Ming Chiao Tung University, Taipei 11217, Taiwan
| | - Chang-Chi Weng
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 11217, Taiwan;
| | - Yu-Ling Ko
- Department of Medical Research, Taipei Veteran General Hospital, Taipei 11217, Taiwan; (Y.-P.Y.); (Y.-H.L.); (P.-H.T.); (Y.-J.H.); (L.H.N.); (X.-Z.L.); (Y.-L.K.); (S.-H.C.)
| | - Chang-Hao Yang
- Department of Ophthalmology, National Taiwan University Hospital, Taipei 10002, Taiwan;
- Department of Ophthalmology, College of Medicine, National Taiwan University, Taipei 11217, Taiwan
| | - De-Kuang Hwang
- School of Medicine, National Yang-Ming Chiao Tung University, Taipei 11217, Taiwan; (D.-K.H.); (S.-J.C.); (A.-G.W.)
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 11217, Taiwan;
| | - Shih-Jen Chen
- School of Medicine, National Yang-Ming Chiao Tung University, Taipei 11217, Taiwan; (D.-K.H.); (S.-J.C.); (A.-G.W.)
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 11217, Taiwan;
| | - Shih-Hwa Chiou
- Department of Medical Research, Taipei Veteran General Hospital, Taipei 11217, Taiwan; (Y.-P.Y.); (Y.-H.L.); (P.-H.T.); (Y.-J.H.); (L.H.N.); (X.-Z.L.); (Y.-L.K.); (S.-H.C.)
- School of Medicine, National Yang-Ming Chiao Tung University, Taipei 11217, Taiwan; (D.-K.H.); (S.-J.C.); (A.-G.W.)
- Institute of Pharmacology, College of Medicine, National Yang Ming Chiao Tung University, Taipei 11217, Taiwan
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 11217, Taiwan;
- Genomic Research Center, Academia Sinica, Taipei 11217, Taiwan
| | - Guang-Yuh Chiou
- Department of Biological Science and Technology, College of Biological Science and Technology, National Yang Ming Chiao Tung University, Hsinchu 300093, Taiwan
- Correspondence: (G.-Y.C.); (Y.C.)
| | - An-Guor Wang
- School of Medicine, National Yang-Ming Chiao Tung University, Taipei 11217, Taiwan; (D.-K.H.); (S.-J.C.); (A.-G.W.)
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 11217, Taiwan;
| | - Yueh Chien
- Department of Medical Research, Taipei Veteran General Hospital, Taipei 11217, Taiwan; (Y.-P.Y.); (Y.-H.L.); (P.-H.T.); (Y.-J.H.); (L.H.N.); (X.-Z.L.); (Y.-L.K.); (S.-H.C.)
- School of Medicine, National Yang-Ming Chiao Tung University, Taipei 11217, Taiwan; (D.-K.H.); (S.-J.C.); (A.-G.W.)
- Correspondence: (G.-Y.C.); (Y.C.)
| |
Collapse
|
25
|
Siedlecki J, Koenig S, Catarino C, Schaumberger MM, Schworm B, Priglinger SG, Rudolph G, von Livonius B, Klopstock T, Priglinger CS. Childhood versus early-teenage onset Leber's hereditary optic neuropathy: visual prognosis and capacity for recovery. Br J Ophthalmol 2022:bjophthalmol-2021-320580. [PMID: 35190400 DOI: 10.1136/bjophthalmol-2021-320580] [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: 10/21/2021] [Accepted: 01/22/2022] [Indexed: 11/03/2022]
Abstract
OBJECTIVE In Leber's hereditary optic neuropathy (LHON) in children and teenagers, the influence of age on visual prognosis has not yet been investigated. METHODS Patients from the mitoNET registry with LHON onset at age 4-16 years with at least 4 years of follow-up without treatment were included. Visual acuity (VA) at baseline, lowest VA ever recorded (nadir) and VA at end of follow-up were compared between childhood onset (ChO, ≤12 years of age) and early-teenage onset (eTO; 13-16 years). RESULTS Out of 231 patients with LHON, 19 met the inclusion criteria (8.2%). There were 11 patients in the ChO and 8 patients in the eTO group. Mean age at onset was 8.6 (SD 2.1) years (ChO) and 15.4 (SD 0.7) years (eTO) (p<0.00001). Follow-up was mean 184 (SD 129) months (ChO) and 119 (SD 78) months (eTO) (p=0.22). Baseline VA was similar between both groups in better (p=0.96) and worse eyes (p=0.54). In worse eyes, both groups deteriorated similarly (p=0.79) until nadir and showed similar recovery until end of follow-up (p=0.38). In better eyes, both groups deteriorated similarly (p=0.16) until nadir. From nadir until end of follow-up, better eyes in the ChO group showed a significantly better recovery (-0.35 (SD 0.36) vs -0.01 (SD 0.06) logMAR; p=0.02) than eTO eyes. CONCLUSION Visual prognosis of LHON in children is much more favourable in cases of childhood onset (≤12 years of age) as compared with teenage onset (13-16 years), mostly due to better recovery from nadir in childhood onset.
Collapse
Affiliation(s)
- Jakob Siedlecki
- Department of Ophthalmology, Ludwig-Maximilians-Universität München, Munchen, Bayern, Germany
| | - Susanna Koenig
- Department of Ophthalmology, Ludwig-Maximilians-Universität München, Munchen, Bayern, Germany
| | - Claudia Catarino
- Friedrich-Baur-Institut, Neurologische Klinik und Poliklinik, Ludwig-Maximilians-Universität München, Munchen, Bayern, Germany
| | - Markus M Schaumberger
- Department of Ophthalmology, Ludwig-Maximilians-Universität München, Munchen, Bayern, Germany
| | - Benedikt Schworm
- Department of Ophthalmology, Ludwig-Maximilians-Universität München, Munchen, Bayern, Germany
| | | | - Guenther Rudolph
- Department of Ophthalmology, Ludwig-Maximilians-Universität München, Munchen, Bayern, Germany
| | - Bettina von Livonius
- Department of Ophthalmology, Ludwig-Maximilians-Universität München, Munchen, Bayern, Germany
| | - Thomas Klopstock
- Friedrich-Baur-Institut, Neurologische Klinik und Poliklinik, Ludwig-Maximilians-Universität München, Munchen, Bayern, Germany
| | - Claudia S Priglinger
- Department of Ophthalmology, Ludwig-Maximilians-Universität München, Munchen, Bayern, Germany
| |
Collapse
|
26
|
Calzetti G, La Morgia C, Cattaneo M, Carta A, Bosello F, Amore G, Carbonelli M, Cascavilla ML, Gandolfi S, Carelli V, Schmetterer L, Scholl HPN, Barboni P. Longitudinal Study of Optic Disk Perfusion and Retinal Structure in Leber's Hereditary Optic Neuropathy. Invest Ophthalmol Vis Sci 2022; 63:43. [PMID: 35098304 PMCID: PMC8802032 DOI: 10.1167/iovs.63.1.43] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Purpose The purpose of this study was to evaluate optic disk perfusion and neural retinal structure in patients with subacute Leber's hereditary optic neuropathy (LHON) and LHON carriers, as compared with healthy controls. Methods This study included 8 patients with LHON in the subacute stage, 10 asymptomatic carriers of a LHON-associated mitochondrial DNA mutation, and 40 controls. All subjects underwent measurement of the retinal nerve fiber layer (RNFL) thickness, the ganglion cell-inner plexiform layer (GCIPL) thickness using optical coherence tomography and optic disk microvascular perfusion (Mean Tissue [MT]) using laser speckle flowgraphy (LSFG). Patients were re-examined after a median interval of 3 months from the baseline visit. Results LHON carriers had higher values of RNFL thickness, GCIPL thickness, and disk area than controls (P < 0.05), whereas MT was not different between the two groups (P = 0.936). Median MT and RNFL thickness were 32% and 15% higher in the early subacute stage of the disease than in controls (P < 0.001 and P = 0.001). MT declined below the values of controls during the late subacute stage (P = 0.024), whereas RNFL thickness declined later during the dynamic stage (P < 0.001). GCIPL thickness was lower in patients with LHON than in controls independently of the stage of the disease (P < 0.001). Conclusions The high blood flow at the optic disk during the early subacute stage may be the consequence of vasodilation due to nitric oxide release as compensation to mitochondrial impairment. Optic disk perfusion as measured by LSFG is a promising biomarker for LHON diagnosis and monitoring as well as an objective outcome measure for assessing response to therapies.
Collapse
Affiliation(s)
- Giacomo Calzetti
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland.,Department of Ophthalmology, University of Basel, Basel, Switzerland.,Department of Ophthalmology, University Hospital of Parma, Parma, Italy
| | - Chiara La Morgia
- IRCCS, Istituto delle Scienze Neurologiche di Bologna, Ospedale Bellaria, Bologna, Italy
| | - Marco Cattaneo
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland.,Department of Clinical Research, University of Basel, Basel, Switzerland
| | - Arturo Carta
- Department of Ophthalmology, University Hospital of Parma, Parma, Italy
| | - Francesca Bosello
- Department of Neurosciences, Biomedicine and Movement Sciences, Eye Clinic, Ocular Immunology and Neuroophthalmology Service, AOUI-University of Verona, Verona, Italy
| | - Giulia Amore
- Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
| | - Michele Carbonelli
- Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
| | - Maria Lucia Cascavilla
- Department of Ophthalmology, University Vita-Salute, IRCCS Ospedale San Raffaele, Milan, Italy
| | - Stefano Gandolfi
- Department of Ophthalmology, University Hospital of Parma, Parma, Italy
| | - Valerio Carelli
- IRCCS, Istituto delle Scienze Neurologiche di Bologna, Ospedale Bellaria, Bologna, Italy.,Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
| | - Leopold Schmetterer
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland.,Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.,Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria.,Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Hendrik P N Scholl
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland.,Department of Ophthalmology, University of Basel, Basel, Switzerland
| | - Piero Barboni
- Department of Ophthalmology, University Vita-Salute, IRCCS Ospedale San Raffaele, Milan, Italy.,Studio Oculistico d'Azeglio, Bologna, Italy
| |
Collapse
|
27
|
Zeviani M, Carelli V. Mitochondrial Retinopathies. Int J Mol Sci 2021; 23:210. [PMID: 35008635 PMCID: PMC8745158 DOI: 10.3390/ijms23010210] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 12/14/2021] [Accepted: 12/18/2021] [Indexed: 12/13/2022] Open
Abstract
The retina is an exquisite target for defects of oxidative phosphorylation (OXPHOS) associated with mitochondrial impairment. Retinal involvement occurs in two ways, retinal dystrophy (retinitis pigmentosa) and subacute or chronic optic atrophy, which are the most common clinical entities. Both can present as isolated or virtually exclusive conditions, or as part of more complex, frequently multisystem syndromes. In most cases, mutations of mtDNA have been found in association with mitochondrial retinopathy. The main genetic abnormalities of mtDNA include mutations associated with neurogenic muscle weakness, ataxia and retinitis pigmentosa (NARP) sometimes with earlier onset and increased severity (maternally inherited Leigh syndrome, MILS), single large-scale deletions determining Kearns-Sayre syndrome (KSS, of which retinal dystrophy is a cardinal symptom), and mutations, particularly in mtDNA-encoded ND genes, associated with Leber hereditary optic neuropathy (LHON). However, mutations in nuclear genes can also cause mitochondrial retinopathy, including autosomal recessive phenocopies of LHON, and slowly progressive optic atrophy caused by dominant or, more rarely, recessive, mutations in the fusion/mitochondrial shaping protein OPA1, encoded by a nuclear gene on chromosome 3q29.
Collapse
Affiliation(s)
- Massimo Zeviani
- Department of Neurosciences, The Clinical School, University of Padova, 35128 Padova, Italy
- Veneto Institute of Molecular Medicine, Via Orus 2, 35128 Padova, Italy
| | - Valerio Carelli
- Department of Biomedical and Neuromotor Sciences, University of Bologna, 40139 Bologna, Italy
- Programma di Neurogenetica, IRCCS Istituto delle Scienze Neurologiche di Bologna, Via Altura 6, 40139 Bologna, Italy
| |
Collapse
|
28
|
Wang H, Chen H, Han S, Fu Y, Tian Y, Liu Y, Wang A, Hou H, Hu Q. Decreased mitochondrial DNA copy number in nerve cells and the hippocampus during nicotine exposure is mediated by autophagy. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 226:112831. [PMID: 34592525 DOI: 10.1016/j.ecoenv.2021.112831] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 09/20/2021] [Accepted: 09/22/2021] [Indexed: 06/13/2023]
Abstract
Cigarette smoke is a harmful air pollutant and nicotine dependence is the essential cause of the tobacco epidemic. Since mitochondrial abnormalities are associated with substance addiction, in this work we used mitochondrial DNA (mtDNA) copy number as an indicator of mitochondrial function to investigate whether nicotine addicts also exhibit mitochondrial abnormalities. We found significantly lower mtDNA copy number in the peripheral blood of healthy nicotine addicts than in non-smokers, indicating that long-term nicotine exposure through smoking has detrimental effects on mitochondria. We also examined the effects of nicotine on mtDNA levels in a rat conditioned place preference (CPP) model of addiction and in cultured neuron cells, which revealed that the mtDNA copy number was significantly reduced in the hippocampus of CPP rats, in human neuroblastoma SH-SY5Y cells, and in rat pheochromocytoma PC12 cells, suggesting that significantly reduced mtDNA copy number is a potential biomarker of nicotine addiction. In SH-SY5Y cells, nicotine treatment induced several mitochondrial defects, such as increased mtDNA damage, increased reactive oxygen species (ROS) levels, decreased mitochondrial membrane potential (△Ψm), and stimulation of autophagic flux via transcriptional up-regulation of several autophagy-related genes and elevated marker protein accumulation, although genes controlling mtDNA replication were unaffected. In addition, pretreatment with the autophagy inhibitor Bafilomycin A1 led to accumulation of microtubule-associated protein 1 light chain 3b-II (LC3B-II) and counteracted the nicotine-induced decrease in mtDNA copy number. These results were recapitulated in PC12 cells, which also showed significant down-regulation of the marker SQSTM1/P62, suggesting that the decrease in mtDNA copy number is mediated by autophagy. This study shows that prolonged nicotine exposure, such as that in nicotine addicts, leads to a decrease of mtDNA copy number in neurons due to enhanced induction of autophagy. CAPSULE: It was found that smoking or nicotine exposure decreased mtDNA copy number based on population, animal, and cell models, and these effects appear to be mediated by autophagy.
Collapse
Affiliation(s)
- Hongjuan Wang
- China National Tobacco Quality Supervision and Test Center, Zhengzhou, China.
| | - Huan Chen
- China National Tobacco Quality Supervision and Test Center, Zhengzhou, China.
| | - Shulei Han
- China National Tobacco Quality Supervision and Test Center, Zhengzhou, China.
| | - Yaning Fu
- China National Tobacco Quality Supervision and Test Center, Zhengzhou, China.
| | - Yushan Tian
- China National Tobacco Quality Supervision and Test Center, Zhengzhou, China.
| | - Yong Liu
- Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, China.
| | - An Wang
- Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, China.
| | - Hongwei Hou
- China National Tobacco Quality Supervision and Test Center, Zhengzhou, China.
| | - Qingyuan Hu
- China National Tobacco Quality Supervision and Test Center, Zhengzhou, China.
| |
Collapse
|
29
|
Moreira JD, Gopal DM, Kotton DN, Fetterman JL. Gaining Insight into Mitochondrial Genetic Variation and Downstream Pathophysiology: What Can i(PSCs) Do? Genes (Basel) 2021; 12:1668. [PMID: 34828274 PMCID: PMC8624338 DOI: 10.3390/genes12111668] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2021] [Revised: 10/20/2021] [Accepted: 10/21/2021] [Indexed: 12/14/2022] Open
Abstract
Mitochondria are specialized organelles involved in energy production that have retained their own genome throughout evolutionary history. The mitochondrial genome (mtDNA) is maternally inherited and requires coordinated regulation with nuclear genes to produce functional enzyme complexes that drive energy production. Each mitochondrion contains 5-10 copies of mtDNA and consequently, each cell has several hundreds to thousands of mtDNAs. Due to the presence of multiple copies of mtDNA in a mitochondrion, mtDNAs with different variants may co-exist, a condition called heteroplasmy. Heteroplasmic variants can be clonally expanded, even in post-mitotic cells, as replication of mtDNA is not tied to the cell-division cycle. Heteroplasmic variants can also segregate during germ cell formation, underlying the inheritance of some mitochondrial mutations. Moreover, the uneven segregation of heteroplasmic variants is thought to underlie the heterogeneity of mitochondrial variation across adult tissues and resultant differences in the clinical presentation of mitochondrial disease. Until recently, however, the mechanisms mediating the relation between mitochondrial genetic variation and disease remained a mystery, largely due to difficulties in modeling human mitochondrial genetic variation and diseases. The advent of induced pluripotent stem cells (iPSCs) and targeted gene editing of the nuclear, and more recently mitochondrial, genomes now provides the ability to dissect how genetic variation in mitochondrial genes alter cellular function across a variety of human tissue types. This review will examine the origins of mitochondrial heteroplasmic variation and propagation, and the tools used to model mitochondrial genetic diseases. Additionally, we discuss how iPSC technologies represent an opportunity to advance our understanding of human mitochondrial genetics in disease.
Collapse
Affiliation(s)
- Jesse D. Moreira
- Evans Department of Medicine and the Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA 02118, USA; (J.D.M.); (D.M.G.)
| | - Deepa M. Gopal
- Evans Department of Medicine and the Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA 02118, USA; (J.D.M.); (D.M.G.)
- Cardiovascular Medicine Section, Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA
| | - Darrell N. Kotton
- Boston Medical Center, Center for Regenerative Medicine of Boston University, Boston, MA 02118, USA;
- The Pulmonary Center, Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA
| | - Jessica L. Fetterman
- Evans Department of Medicine and the Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA 02118, USA; (J.D.M.); (D.M.G.)
| |
Collapse
|
30
|
Sanz-Morello B, Ahmadi H, Vohra R, Saruhanian S, Freude KK, Hamann S, Kolko M. Oxidative Stress in Optic Neuropathies. Antioxidants (Basel) 2021; 10:1538. [PMID: 34679672 PMCID: PMC8532958 DOI: 10.3390/antiox10101538] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 09/07/2021] [Accepted: 09/12/2021] [Indexed: 01/23/2023] Open
Abstract
Increasing evidence indicates that changes in the redox system may contribute to the pathogenesis of multiple optic neuropathies. Optic neuropathies are characterized by the neurodegeneration of the inner-most retinal neurons, the retinal ganglion cells (RGCs), and their axons, which form the optic nerve. Often, optic neuropathies are asymptomatic until advanced stages, when visual impairment or blindness is unavoidable despite existing treatments. In this review, we describe systemic and, whenever possible, ocular redox dysregulations observed in patients with glaucoma, ischemic optic neuropathy, optic neuritis, hereditary optic neuropathies (i.e., Leber's hereditary optic neuropathy and autosomal dominant optic atrophy), nutritional and toxic optic neuropathies, and optic disc drusen. We discuss aspects related to anti/oxidative stress biomarkers that need further investigation and features related to study design that should be optimized to generate more valuable and comparable results. Understanding the role of oxidative stress in optic neuropathies can serve to develop therapeutic strategies directed at the redox system to arrest the neurodegenerative processes in the retina and RGCs and ultimately prevent vision loss.
Collapse
Affiliation(s)
- Berta Sanz-Morello
- Eye Translational Research Unit, Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2100 Copenhagen, Denmark; (B.S.-M.); (H.A.); (R.V.)
| | - Hamid Ahmadi
- Eye Translational Research Unit, Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2100 Copenhagen, Denmark; (B.S.-M.); (H.A.); (R.V.)
- Department of Ophthalmology, Rigshospitalet, 2600 Glostrup, Denmark;
| | - Rupali Vohra
- Eye Translational Research Unit, Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2100 Copenhagen, Denmark; (B.S.-M.); (H.A.); (R.V.)
- Group of Stem Cell Models for Studies of Neurodegenerative Diseases, Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 1870 Frederiksberg, Denmark; (S.S.); (K.K.F.)
| | - Sarkis Saruhanian
- Group of Stem Cell Models for Studies of Neurodegenerative Diseases, Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 1870 Frederiksberg, Denmark; (S.S.); (K.K.F.)
| | - Kristine Karla Freude
- Group of Stem Cell Models for Studies of Neurodegenerative Diseases, Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 1870 Frederiksberg, Denmark; (S.S.); (K.K.F.)
| | - Steffen Hamann
- Department of Ophthalmology, Rigshospitalet, 2600 Glostrup, Denmark;
| | - Miriam Kolko
- Eye Translational Research Unit, Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2100 Copenhagen, Denmark; (B.S.-M.); (H.A.); (R.V.)
- Department of Ophthalmology, Rigshospitalet, 2600 Glostrup, Denmark;
| |
Collapse
|
31
|
Zaslavsky K, Margolin EA. Leber's Hereditary Optic Neuropathy in Older Individuals Because of Increased Alcohol Consumption During the COVID-19 Pandemic. J Neuroophthalmol 2021; 41:316-320. [PMID: 34415266 DOI: 10.1097/wno.0000000000001333] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Leber's hereditary optic neuropathy (LHON) is a disorder affecting oxidative phosphorylation in mitochondria. A majority of affected patients are men of 15 to 35 years of age. Phenotypic penetrance of this condition is only 50% in man and 10% in women and increases if the cellular energy demands go up, with the most common risk factors being smoking and alcohol use. METHODS Review of clinical features of 3 patients who were diagnosed with LHON in their sixth decade of life after doubling their alcohol intake during the recent COVID-19 pandemic. RESULTS All 3 patients were older than the age of 50 when they developed severe sequential visual loss. All have at least doubled their alcohol intake for at least 4 weeks preceding visual loss, and 2 who were smokers increased the number of cigarettes consumed daily because of the stress and boredom during the lockdowns triggered by the pandemic. CONCLUSIONS Significant increase in substance abuse in the general population during the recent lockdowns to combat the COVID-19 pandemic is well documented. We report 3 patients older than the age of 50, one of them a woman, who developed severe bilateral visual loss due to LHON after doubling their alcohol consumption and increasing number of cigarettes smoked daily during the pandemic. Clinicians are reminded to consider LHON in the differential diagnosis when encountering older patients with bilateral sequential visual loss and to specifically inquire about alcohol use and cigarette smoking in these patients.
Collapse
Affiliation(s)
- Kirill Zaslavsky
- Departments of Ophthalmology and Vision Sciences (KZ, EM), University of Toronto, Toronto, Canada ; and Department of Medicine (EM), Division of Neurology, University of Toronto, Toronto, Canada
| | | |
Collapse
|
32
|
Picard M. Blood mitochondrial DNA copy number: What are we counting? Mitochondrion 2021; 60:1-11. [PMID: 34157430 PMCID: PMC8464495 DOI: 10.1016/j.mito.2021.06.010] [Citation(s) in RCA: 58] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 06/12/2021] [Accepted: 06/17/2021] [Indexed: 02/06/2023]
Abstract
There is growing scientific interest to develop scalable biological measures that capture mitochondrial (dys)function. Mitochondria have their own genome, the mitochondrial DNA (mtDNA). It has been proposed that the number of mtDNA copies per cell (mtDNA copy number; mtDNAcn) reflects mitochondrial health. The common availability of stored DNA material or existing DNA sequencing data, especially from blood and other easy-to-collect samples, has made its quantification a popular approach in clinical and epidemiological studies. However, the interpretation of mtDNAcn is not univocal, and either a reduction or elevation in mtDNAcn can indicate dysfunction. The major determinants of blood-derived mtDNAcn are the heterogeneous cell type composition of leukocytes and platelet abundance, which can change with time of day, aging, and with disease. Hematopoiesis is a likely driver of blood mtDNAcn. Here we discuss the rationale and available methods to quantify mtDNAcn, the influence of blood cell type variations, and consider important gaps in knowledge that need to be resolved to maximize the scientific value around the investigation of blood mtDNAcn.
Collapse
Affiliation(s)
- Martin Picard
- Department of Psychiatry, Division of Behavioral Medicine, Columbia University Irving Medical Center, New York, NY, USA; Department of Neurology, Merritt Center, Columbia Translational Neuroscience Initiative, Columbia University Irving Medical Center, New York, NY, USA; New York State Psychiatric Institute, New York, NY, USA.
| |
Collapse
|
33
|
Maremanda KP, Sundar IK, Rahman I. Role of inner mitochondrial protein OPA1 in mitochondrial dysfunction by tobacco smoking and in the pathogenesis of COPD. Redox Biol 2021; 45:102055. [PMID: 34214709 PMCID: PMC8258692 DOI: 10.1016/j.redox.2021.102055] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 06/19/2021] [Accepted: 06/20/2021] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Chronic lung diseases, such as chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis (IPF) are linked to several mitochondrial alterations. Cigarette smoke (CS) alters the structure and function of mitochondria. OPA1 is the main inner mitochondrial GTPase responsible for the fusion events. OPA1 undergoes proteolytic cleavage from long to short forms during acute stress and mitophagy. However, the exact role of OPA1 isoforms and related proteins during CS-induced mitophagy and COPD is not clear. METHODS Lung tissues from non-smokers, smokers, COPD and IPF were used to determine the relative expression of OPA1 and related proteins. Additionally, we used mouse lungs from chronic (6 months) CS exposure to evaluate the status of OPA1. Primary lung fibroblasts from normal and COPD patients and naked mole rat (NMR) lung fibroblasts, human fetal lung fibroblast (HFL1), mouse embryonic fibroblast from wild type (WT), OPA1-/-, MFN1 and MFN2-/- were used to determine the effect of CS on OPA1 isoforms. Various mitochondrial fusion promoters/activators (BGP-15, leflunomide, M1) and fission inhibitor (DRP1) were used to determine their effect on OPA1 status and cigarette smoke extract (CSE)-induced lung epithelial (BEAS2B) cell damage, respectively. Seahorse flux analyzer was used to determine the effect of these compounds in BEAS2B cells with and without CSE exposure. FINDINGS Short OPA1 isoforms were predominantly detected and significantly increased in COPD subjects. Acute CSE treatment in various cell lines except NMR was found to increase the conversion of long to short OPA1 isoforms. CSE treatment significantly increased mitochondrial stress-related protein SLP2 in all the cells used. OPA1 interacting partners like prohibitins (PHB1 and 2) were also altered depending on the CS exposure. Finally, BGP-15 and leflunomide treatment were able to preserve the long OPA1 isoform in cells treated with CSE. INTERPRETATION/CONCLUSION The long OPA1 isoform along with SLP2 and prohibitins play a crucial role in CS-induced lung damage, causing mitophagy/mitochondrial dysfunction in COPD, which may be used as a novel therapeutic target in COPD.
Collapse
Affiliation(s)
| | - Isaac Kirubakaran Sundar
- Division of Pulmonary Critical Care and Sleep Medicine, Department of Internal Medicine, University of Kansas Medical Center, Kansas City, KS, USA
| | - Irfan Rahman
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, NY, USA.
| |
Collapse
|
34
|
Sundaramurthy S, SelvaKumar A, Ching J, Dharani V, Sarangapani S, Yu-Wai-Man P. Leber hereditary optic neuropathy-new insights and old challenges. Graefes Arch Clin Exp Ophthalmol 2021; 259:2461-2472. [PMID: 33185731 DOI: 10.1007/s00417-020-04993-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 09/16/2020] [Accepted: 10/23/2020] [Indexed: 12/20/2022] Open
Abstract
Leber hereditary optic neuropathy (LHON) is the most common primary mitochondrial DNA (mtDNA) disorder with the majority of patients harboring one of three primary mtDNA point mutations, namely, m.3460G>A (MTND1), m.11778G>A (MTND4), and m.14484T>C (MTND6). LHON is characterized by bilateral subacute loss of vision due to the preferential loss of retinal ganglion cells (RGCs) within the inner retina, resulting in optic nerve degeneration. This review describes the clinical features associated with mtDNA LHON mutations and recent insights gained into the disease mechanisms contributing to RGC loss in this mitochondrial disorder. Although treatment options remain limited, LHON research has now entered an active translational phase with ongoing clinical trials, including gene therapy to correct the underlying pathogenic mtDNA mutation.
Collapse
Affiliation(s)
- Srilekha Sundaramurthy
- 1SN Oil and Natural Gas Corporation (ONGC) Department of Genetics & Molecular Biology, Vision Research Foundation, Chennai, India.
| | - Ambika SelvaKumar
- Department of Neuro-Ophthalmology, Medical Research Foundation, Chennai, India
| | - Jared Ching
- Cambridge Eye Unit, Addenbrooke's Hospital, Cambridge University Hospitals, Cambridge, UK
- John Van Geest Centre for Brain Repair and MRC Mitochondrial Biology Unit, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Vidhya Dharani
- Department of Neuro-Ophthalmology, Medical Research Foundation, Chennai, India
| | - Sripriya Sarangapani
- 1SN Oil and Natural Gas Corporation (ONGC) Department of Genetics & Molecular Biology, Vision Research Foundation, Chennai, India
| | - Patrick Yu-Wai-Man
- Cambridge Eye Unit, Addenbrooke's Hospital, Cambridge University Hospitals, Cambridge, UK
- John Van Geest Centre for Brain Repair and MRC Mitochondrial Biology Unit, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
- NIHR Biomedical Research Centre, Moorfields Eye Hospital and UCL Institute of Ophthalmology, London, UK
| |
Collapse
|
35
|
Mohana Devi S, Abishek Kumar B, Mahalaxmi I, Balachandar V. Leber's hereditary optic neuropathy: Current approaches and future perspectives on Mesenchymal stem cell-mediated rescue. Mitochondrion 2021; 60:201-218. [PMID: 34454075 DOI: 10.1016/j.mito.2021.08.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 08/03/2021] [Accepted: 08/23/2021] [Indexed: 12/19/2022]
Abstract
Leber's Hereditary Optic Neuropathy (LHON) is an inherited optic nerve disorder. It is a mitochondrially inherited disease due to point mutation in the MT-ND1, MT-ND4, and MT-ND6 genes of mitochondrial DNA (mtDNA) coding for complex I subunit proteins. These mutations affect the assembly of the mitochondrial complex I and hence the electron transport chain leading to mitochondrial dysfunction and oxidative damage. Optic nerve cells like retinal ganglion cells (RGCs) are more sensitive to mitochondrial loss and oxidative damage which results in the progressive degeneration of RGCs at the axonal region of the optic nerve leading to bilateral vision loss. Currently, gene therapy using Adeno-associated viral vector (AAV) is widely studied for the therapeutics application in LHON. Our review highlights the application of cell-based therapy for LHON. Mesenchymal stem cells (MSCs) are known to rescue cells from the pre-apoptotic stage by transferring healthy mitochondria through tunneling nanotubes (TNT) for cellular oxidative function. Empowering the transfer of healthy mitochondria using MSCs may replace the mitochondria with pathogenic mutation and possibly benefit the cells from progressive damage. This review discusses the ongoing research in LHON and mitochondrial transfer mechanisms to explore its scope in inherited optic neuropathy.
Collapse
Affiliation(s)
- Subramaniam Mohana Devi
- SN ONGC Department of Genetics and Molecular Biology, Vision Research Foundation, Sankara Nethralaya, Chennai, India.
| | - B Abishek Kumar
- SN ONGC Department of Genetics and Molecular Biology, Vision Research Foundation, Sankara Nethralaya, Chennai, India
| | - Iyer Mahalaxmi
- Livestock Farming and Bioresource Technology, Tamil Nadu, India
| | - Vellingiri Balachandar
- Department of Human Genetics and Molecular Biology, Bharathiar University, Coimbatore, India
| |
Collapse
|
36
|
Yang TC, Yarmishyn AA, Yang YP, Lu PC, Chou SJ, Wang ML, Lin TC, Hwang DK, Chou YB, Chen SJ, Yu WK, Wang AG, Hsu CC, Chiou SH. Mitochondrial transport mediates survival of retinal ganglion cells in affected LHON patients. Hum Mol Genet 2021; 29:1454-1464. [PMID: 32277753 DOI: 10.1093/hmg/ddaa063] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 03/02/2020] [Accepted: 03/30/2020] [Indexed: 01/17/2023] Open
Abstract
The mutations in the genes encoding the subunits of complex I of the mitochondrial electron transport chain are the most common cause of Leber's hereditary optic neuropathy (LHON), a maternal hereditary disease characterized by retinal ganglion cell (RGC) degeneration. The characteristics of incomplete penetrance indicate that nuclear genetic and environmental factors also determine phenotypic expression of LHON. Therefore, further understanding of the role of mutant mitochondrial nicotinamide adenine dinucleotide dehydrogenase subunit proteins and nuclear genetic factors/environmental effects in the etiology of LHON is needed. In this study, we generated human-induced pluripotent stem cells (hiPSCs) from healthy control, unaffected LHON mutation carrier, and affected LHON patient. hiPSC-derived RGCs were used to study the differences between affected and unaffected carriers of mitochondrial DNA point mutation m.11778G > A in the MT-ND4 gene. We found that both mutated cell lines were characterized by increase in reactive oxygen species production, however, only affected cell line had increased levels of apoptotic cells. We found a significant increase in retrograde mitochondria and a decrease in stationary mitochondria in the affected RGC axons. In addition, the messenger RNA and protein levels of KIF5A in the LHON-affected RGCs were significantly reduced. Antioxidant N-acetyl-L-cysteine could restore the expression of KIF5A and the normal pattern of mitochondrial movement in the affected RGCs. To conclude, we found essential differences in the mutually dependent processes of oxidative stress, mitochondrial transport and apoptosis between two LHON-specific mutation carrier RGC cell lines, asymptomatic carrier and disease-affected, and identified KIF5A as a central modulator of these differences.
Collapse
Affiliation(s)
- Tien-Chun Yang
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | | | - Yi-Ping Yang
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan.,School of Pharmaceutical Sciences, National Yang-Ming University, Taipei 11221, Taiwan.,School of Medicine, National Yang-Ming University, Taipei 11221, Taiwan
| | - Pin-Chen Lu
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | - Shih-Jie Chou
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan.,Institute of Pharmacology, National Yang-Ming University, Taipei 11221, Taiwan
| | - Mong-Lien Wang
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan.,School of Pharmaceutical Sciences, National Yang-Ming University, Taipei 11221, Taiwan.,School of Medicine, National Yang-Ming University, Taipei 11221, Taiwan.,Institute of Pharmacology, National Yang-Ming University, Taipei 11221, Taiwan
| | - Tai-Chi Lin
- School of Medicine, National Yang-Ming University, Taipei 11221, Taiwan.,Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | - De-Kuang Hwang
- School of Medicine, National Yang-Ming University, Taipei 11221, Taiwan.,Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | - Yu-Bai Chou
- School of Medicine, National Yang-Ming University, Taipei 11221, Taiwan.,Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | - Shih-Jen Chen
- School of Medicine, National Yang-Ming University, Taipei 11221, Taiwan.,Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | - Wei-Kuang Yu
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | - An-Guor Wang
- School of Medicine, National Yang-Ming University, Taipei 11221, Taiwan.,Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | - Chih-Chien Hsu
- School of Medicine, National Yang-Ming University, Taipei 11221, Taiwan.,Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | - Shih-Hwa Chiou
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan.,School of Pharmaceutical Sciences, National Yang-Ming University, Taipei 11221, Taiwan.,Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| |
Collapse
|
37
|
Maresca A, Carelli V. Molecular Mechanisms behind Inherited Neurodegeneration of the Optic Nerve. Biomolecules 2021; 11:496. [PMID: 33806088 PMCID: PMC8064499 DOI: 10.3390/biom11040496] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 03/22/2021] [Accepted: 03/23/2021] [Indexed: 01/01/2023] Open
Abstract
Inherited neurodegeneration of the optic nerve is a paradigm in neurology, as many forms of isolated or syndromic optic atrophy are encountered in clinical practice. The retinal ganglion cells originate the axons that form the optic nerve. They are particularly vulnerable to mitochondrial dysfunction, as they present a peculiar cellular architecture, with axons that are not myelinated for a long intra-retinal segment, thus, very energy dependent. The genetic landscape of causative mutations and genes greatly enlarged in the last decade, pointing to common pathways. These mostly imply mitochondrial dysfunction, which leads to a similar outcome in terms of neurodegeneration. We here critically review these pathways, which include (1) complex I-related oxidative phosphorylation (OXPHOS) dysfunction, (2) mitochondrial dynamics, and (3) endoplasmic reticulum-mitochondrial inter-organellar crosstalk. These major pathogenic mechanisms are in turn interconnected and represent the target for therapeutic strategies. Thus, their deep understanding is the basis to set and test new effective therapies, an urgent unmet need for these patients. New tools are now available to capture all interlinked mechanistic intricacies for the pathogenesis of optic nerve neurodegeneration, casting hope for innovative therapies to be rapidly transferred into the clinic and effectively cure inherited optic neuropathies.
Collapse
Affiliation(s)
- Alessandra Maresca
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Programma di Neurogenetica, 40139 Bologna, Italy;
| | - Valerio Carelli
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Programma di Neurogenetica, 40139 Bologna, Italy;
- Department of Biomedical and Neuromotor Sciences, University of Bologna, 40139 Bologna, Italy
| |
Collapse
|
38
|
Wiggs JL. DNAJC30 biallelic mutations extend mitochondrial complex I-deficient phenotypes to include recessive Leber's hereditary optic neuropathy. J Clin Invest 2021; 131:147734. [PMID: 33720041 DOI: 10.1172/jci147734] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Leber's hereditary optic neuropathy (LHON) is the most common mitochondrial disease and in most cases is caused by mutations in mitochondrial DNA-encoded (mtDNA-encoded) respiratory complex I subunit ND1, ND4, or ND6. In this issue of the JCI, Stenton et al. describe biallelic mutations in a nuclear DNA-encoded gene, DNAJC30, establishing recessively inherited LHON (arLHON). Functional studies suggest that DNAJC30 is a protein chaperone required for exchange of damaged complex I subunits. Hallmark mtDNA LHON features were also found in arLHON, including incomplete penetrance, male predominance, and positive response to idebenone therapy. These results extend complex I-deficient phenotypes to include recessively inherited optic neuropathy, with important clinical implications for genetic counseling and therapeutic considerations.
Collapse
|
39
|
Reinert MC, Pacheu-Grau D, Catarino CB, Klopstock T, Ohlenbusch A, Schittkowski M, Wilichowski E, Rehling P, Brockmann K. Sulthiame impairs mitochondrial function in vitro and may trigger onset of visual loss in Leber hereditary optic neuropathy. Orphanet J Rare Dis 2021; 16:64. [PMID: 33541401 PMCID: PMC7860214 DOI: 10.1186/s13023-021-01690-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 01/15/2021] [Indexed: 01/06/2023] Open
Abstract
Background Leber hereditary optic neuropathy (LHON) is the most common mitochondrial disorder and characterized by acute or subacute painless visual loss. Environmental factors reported to trigger visual loss in LHON mutation carriers include smoking, heavy intake of alcohol, raised intraocular pressure, and some drugs, including several carbonic anhydrase inhibitors. The antiepileptic drug sulthiame (STM) is effective especially in focal seizures, particularly in benign epilepsy of childhood with centrotemporal spikes, and widely used in pediatric epileptology. STM is a sulfonamide derivate and an inhibitor of mammalian carbonic anhydrase isoforms I–XIV. Results We describe two unrelated patients, an 8-year-old girl and an 11-year-old boy, with cryptogenic focal epilepsy, who suffered binocular (subject #1) or monocular (subject #2) visual loss in close temporal connection with starting antiepileptic pharmacotherapy with STM. In both subjects, visual loss was due to LHON. We used real-time respirometry in fibroblasts derived from LHON patients carrying the same mitochondrial mutations as our two subjects to investigate the effect of STM on oxidative phosphorylation. Oxygen consumption rate in fibroblasts from a healthy control was not impaired by STM compared with a vehicle control. In contrast, fibroblasts carrying the m.14484T>C or the m.3460G>A LHON mutation displayed a drastic reduction of the respiration rate when treated with STM compared to vehicle control. Conclusions Our observations point to a causal relationship between STM treatment and onset or worsening of visual failure in two subjects with LHON rather than pure coincidence. We conclude that antiepileptic medication with STM may pose a risk for visual loss in LHON mutation carriers and should be avoided in these patients.
Collapse
Affiliation(s)
- Marie-Christine Reinert
- Division of Pediatric Neurology, Department of Pediatrics and Adolescent Medicine, University Medical Center Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany.
| | - David Pacheu-Grau
- Department of Cellular Biochemistry, University Medical Center Göttingen, Göttingen, Germany
| | - Claudia B Catarino
- Department of Neurology, Friedrich-Baur-Institute, University Hospital, LMU Munich, Munich, Germany
| | - Thomas Klopstock
- Department of Neurology, Friedrich-Baur-Institute, University Hospital, LMU Munich, Munich, Germany.,German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Andreas Ohlenbusch
- Division of Pediatric Neurology, Department of Pediatrics and Adolescent Medicine, University Medical Center Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany
| | - Michael Schittkowski
- Department of Ophthalmology, Section for Strabismus, Neuroophthalmology and Oculoplastics, University Medical Center Göttingen, Göttingen, Germany
| | - Ekkehard Wilichowski
- Division of Pediatric Neurology, Department of Pediatrics and Adolescent Medicine, University Medical Center Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany
| | - Peter Rehling
- Department of Cellular Biochemistry, University Medical Center Göttingen, Göttingen, Germany.,Cluster of Excellence "Multiscale Bioimaging: From Molecular Machines To Networks of Excitable Cells" (MBExC), University of Göttingen, Göttingen, Germany.,Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Knut Brockmann
- Interdisciplinary Pediatric Center for Children With Developmental Disabilities and Severe Chronic Disorders, University Medical Center Göttingen, Göttingen, Germany
| |
Collapse
|
40
|
Botelho GIS, Salomão SR, Tengan CH, Karanjia R, Moura FV, Rocha DM, da Silva PBE, Fernandes AG, Watanabe SES, Sacai PY, Belfort R, Carelli V, Sadun AA, Berezovsky A. Impaired Ganglion Cell Function Objectively Assessed by the Photopic Negative Response in Affected and Asymptomatic Members From Brazilian Families With Leber's Hereditary Optic Neuropathy. Front Neurol 2021; 11:628014. [PMID: 33584522 PMCID: PMC7874135 DOI: 10.3389/fneur.2020.628014] [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: 11/10/2020] [Accepted: 12/21/2020] [Indexed: 01/13/2023] Open
Abstract
Purpose: The photopic negative response (PhNR) is an electrophysiological method that provides retinal ganglion cell function assessment using full-field stimulation that does not require clear optics or refractive correction. The purpose of this study was to assess ganglion cell function by PhNR in affected and asymptomatic carriers from Brazilian families with LHON. Methods: Individuals either under suspicion or previously diagnosed with LHON and their family members were invited to participate in this cross-sectional study. Screening for the most frequent LHON mtDNA mutations was performed. Visual acuity, color discrimination, visual fields, pattern-reversal visual evoked potentials (PRVEP), full-field electroretinography and PhNR were tested. A control group of healthy subjects was included. Full-field ERG PhNR were recorded using red (640 nm) flashes at 1 cd.s/m2, on blue (470 nm) rod saturating background. PhNR amplitude (μV) was measured using baseline-to-trough (BT). Optical coherence tomography scans of both the retinal nerve fiber layer (RNFL) and ganglion cell complex (GCC) were measured. PhNR amplitudes among affected, carriers and controls were compared by Kruskal-Wallis test followed by post-hoc Dunn test. The associations between PhNR amplitude and OCT parameters were analyzed by Spearman rank correlation. Results: Participants were 24 LHON affected patients (23 males, mean age=30.5 ± 11.4 yrs) from 19 families with the following genotype: m.11778G>A [N = 15 (62%), 14 males]; m.14484T>C [N = 5 (21%), all males] and m.3460G>A [N = 4 (17%), all males] and 14 carriers [13 females, mean age: 43.2 ± 13.3 yrs; m.11778G>A (N = 11); m.3460G>A (N = 2) and m.14484T>C (N = 1)]. Controls were eight females and seven males (mean age: 32.6 ± 11.5 yrs). PhNR amplitudes were significantly reduced (p = 0.0001) in LHON affected (-5.96 ± 3.37 μV) compared to carriers (-16.53 ± 3.40 μV) and controls (-23.91 ± 4.83; p < 0.0001) and in carriers compared to controls (p = 0.01). A significant negative correlation was found between PhNR amplitude and total macular ganglion cell thickness (r = -0.62, p < 0.05). Severe abnormalities in color discrimination, visual fields and PRVEPs were found in affected and subclinical abnormalities in carriers. Conclusions: In this cohort of Brazilian families with LHON the photopic negative response was severely reduced in affected patients and mildly reduced in asymptomatic carriers suggesting possible subclinical abnormalities in the latter. These findings were similar among pathogenic mutations.
Collapse
Affiliation(s)
- Gabriel Izan Santos Botelho
- Departamento de Oftalmologia e Ciências Visuais, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Solange Rios Salomão
- Departamento de Oftalmologia e Ciências Visuais, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Célia Harumi Tengan
- Departamento de Neurologia e Neurocirurgia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Rustum Karanjia
- Doheny Eye Institute, University of California Los Angeles, Los Angeles, CA, United States.,Department of Ophthalmology, Doheny Eye Center, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States.,Ottawa Eye Institute, University of Ottawa, Ottawa, ON, Canada.,Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Felipo Victor Moura
- Departamento de Neurologia e Neurocirurgia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Daniel Martins Rocha
- Departamento de Oftalmologia e Ciências Visuais, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Paula Baptista Eliseo da Silva
- Departamento de Oftalmologia e Ciências Visuais, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Arthur Gustavo Fernandes
- Departamento de Oftalmologia e Ciências Visuais, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Sung Eun Song Watanabe
- Departamento de Oftalmologia e Ciências Visuais, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Paula Yuri Sacai
- Departamento de Oftalmologia e Ciências Visuais, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Rubens Belfort
- Departamento de Oftalmologia e Ciências Visuais, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil.,Instituto da Visão-IPEPO, São Paulo, Brazil
| | - Valerio Carelli
- Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna School of Medicine, Bologna, Italy
| | - Alfredo Arrigo Sadun
- Doheny Eye Institute, University of California Los Angeles, Los Angeles, CA, United States.,Department of Ophthalmology, Doheny Eye Center, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States
| | - Adriana Berezovsky
- Departamento de Oftalmologia e Ciências Visuais, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| |
Collapse
|
41
|
Kim HD. Reply to the letter titled "More likely than through head trauma, is LHON triggered by mitochondrion-toxic drugs or oxidative stress". Doc Ophthalmol 2021; 142:397-398. [PMID: 33427992 DOI: 10.1007/s10633-020-09816-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Accepted: 12/28/2020] [Indexed: 10/22/2022]
Affiliation(s)
- Hoon Dong Kim
- Department of Ophthalmology, College of Medicine, Soonchunhyang University, Cheonan, Korea.
| |
Collapse
|
42
|
Amore G, Romagnoli M, Carbonelli M, Barboni P, Carelli V, La Morgia C. Therapeutic Options in Hereditary Optic Neuropathies. Drugs 2021; 81:57-86. [PMID: 33159657 PMCID: PMC7843467 DOI: 10.1007/s40265-020-01428-3] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Options for the effective treatment of hereditary optic neuropathies have been a long time coming. The successful launch of the antioxidant idebenone for Leber's Hereditary Optic Neuropathy (LHON), followed by its introduction into clinical practice across Europe, was an important step forward. Nevertheless, other options, especially for a variety of mitochondrial optic neuropathies such as dominant optic atrophy (DOA), are needed, and a number of pharmaceutical agents, acting on different molecular pathways, are currently under development. These include gene therapy, which has reached Phase III development for LHON, but is expected to be developed also for DOA, whilst most of the other agents (other antioxidants, anti-apoptotic drugs, activators of mitobiogenesis, etc.) are almost all at Phase II or at preclinical stage of research. Here, we review proposed target mechanisms, preclinical evidence, available clinical trials with primary endpoints and results, of a wide range of tested molecules, to give an overview of the field, also providing the landscape of future scenarios, including gene therapy, gene editing, and reproductive options to prevent transmission of mitochondrial DNA mutations.
Collapse
Affiliation(s)
- Giulia Amore
- Dipartimento di Scienze Biomediche e Neuromotorie, Università di Bologna, Bologna, Italy
| | - Martina Romagnoli
- IRCCS Istituto delle Scienze Neurologiche di Bologna, UOC Clinica Neurologica, Bologna, Via Altura 3, 40139, Bologna, Italy
| | - Michele Carbonelli
- IRCCS Istituto delle Scienze Neurologiche di Bologna, UOC Clinica Neurologica, Bologna, Via Altura 3, 40139, Bologna, Italy
| | | | - Valerio Carelli
- Dipartimento di Scienze Biomediche e Neuromotorie, Università di Bologna, Bologna, Italy
- IRCCS Istituto delle Scienze Neurologiche di Bologna, UOC Clinica Neurologica, Bologna, Via Altura 3, 40139, Bologna, Italy
| | - Chiara La Morgia
- IRCCS Istituto delle Scienze Neurologiche di Bologna, UOC Clinica Neurologica, Bologna, Via Altura 3, 40139, Bologna, Italy.
| |
Collapse
|
43
|
Toxische Retinopathien. Ophthalmologe 2020; 117:1247-1266. [DOI: 10.1007/s00347-020-01260-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
44
|
Cocco MP, White E, Xiao S, Hu D, Mak A, Sleiman P, Yang M, Bobbitt KR, Gui H, Levin AM, Hochstadt S, Whitehouse K, Rynkowski D, Barczak AJ, Abecasis G, Blackwell TW, Kang HM, Nickerson DA, Germer S, Ding J, Lanfear DE, Gilliland F, Gauderman WJ, Kumar R, Erle DJ, Martinez F, Hakonarson H, Burchard EG, Williams LK. Asthma and its relationship to mitochondrial copy number: Results from the Asthma Translational Genomics Collaborative (ATGC) of the Trans-Omics for Precision Medicine (TOPMed) program. PLoS One 2020; 15:e0242364. [PMID: 33237978 PMCID: PMC7688161 DOI: 10.1371/journal.pone.0242364] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 10/30/2020] [Indexed: 02/07/2023] Open
Abstract
Background Mitochondria support critical cellular functions, such as energy production through oxidative phosphorylation, regulation of reactive oxygen species, apoptosis, and calcium homeostasis. Objective Given the heightened level of cellular activity in patients with asthma, we sought to determine whether mitochondrial DNA (mtDNA) copy number measured in peripheral blood differed between individuals with and without asthma. Methods Whole genome sequence data was generated as part of the Trans-Omics for Precision Medicine (TOPMed) Program on participants from the Study of Asthma Phenotypes and Pharmacogenomic Interactions by Race-ethnicity (SAPPHIRE) and the Study of African Americans, Asthma, Genes, & Environment II (SAGE II). We restricted our analysis to individuals who self-identified as African American (3,651 asthma cases and 1,344 controls). Mitochondrial copy number was estimated using the sequencing read depth ratio for the mitochondrial and nuclear genomes. Respiratory complex expression was assessed using RNA-sequencing. Results Average mitochondrial copy number was significantly higher among individuals with asthma when compared with controls (SAPPHIRE: 218.60 vs. 200.47, P<0.001; SAGE II: 235.99 vs. 223.07, P<0.001). Asthma status was significantly associated with mitochondrial copy number after accounting for potential explanatory variables, such as participant age, sex, leukocyte counts, and mitochondrial haplogroup. Despite the consistent relationship between asthma status and mitochondrial copy number, the latter was not associated with time-to-exacerbation or patient-reported asthma control. Mitochondrial respiratory complex gene expression was disproportionately lower in individuals with asthma when compared with individuals without asthma and other protein-encoding genes. Conclusions We observed a robust association between asthma and higher mitochondrial copy number. Asthma having an effect on mitochondria function was also supported by lower respiratory complex gene expression in this group.
Collapse
Affiliation(s)
- Maxwell P. Cocco
- Center for Individualized and Genomic Medicine Research (CIGMA), Department of Internal Medicine, Henry Ford Health System, Detroit, Michigan, United States of America
| | - Evan White
- Center for Individualized and Genomic Medicine Research (CIGMA), Department of Internal Medicine, Henry Ford Health System, Detroit, Michigan, United States of America
| | - Shujie Xiao
- Center for Individualized and Genomic Medicine Research (CIGMA), Department of Internal Medicine, Henry Ford Health System, Detroit, Michigan, United States of America
| | - Donglei Hu
- Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
| | - Angel Mak
- Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
| | - Patrick Sleiman
- Center for Applied Genomics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Mao Yang
- Center for Individualized and Genomic Medicine Research (CIGMA), Department of Internal Medicine, Henry Ford Health System, Detroit, Michigan, United States of America
| | - Kevin R. Bobbitt
- Department of Public Health Sciences, Henry Ford Health System, Detroit, Michigan, United States of America
| | - Hongsheng Gui
- Center for Individualized and Genomic Medicine Research (CIGMA), Department of Internal Medicine, Henry Ford Health System, Detroit, Michigan, United States of America
| | - Albert M. Levin
- Department of Public Health Sciences, Henry Ford Health System, Detroit, Michigan, United States of America
| | - Samantha Hochstadt
- Center for Individualized and Genomic Medicine Research (CIGMA), Department of Internal Medicine, Henry Ford Health System, Detroit, Michigan, United States of America
| | - Kyle Whitehouse
- Center for Individualized and Genomic Medicine Research (CIGMA), Department of Internal Medicine, Henry Ford Health System, Detroit, Michigan, United States of America
| | - Dean Rynkowski
- Center for Individualized and Genomic Medicine Research (CIGMA), Department of Internal Medicine, Henry Ford Health System, Detroit, Michigan, United States of America
| | - Andrea J. Barczak
- Lung Biology Center and UCSF CoLabs, University of California San Francisco, San Francisco, California, United States of America
| | - Gonçalo Abecasis
- Center for Statistical Genetics, University of Michigan, Ann Arbor, Michigan, United States of America
- Regeneron Pharmaceuticals, Inc., Tarrytown, New York, United States of America
| | - Thomas W. Blackwell
- Center for Statistical Genetics, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Hyun Min Kang
- Center for Statistical Genetics, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Deborah A. Nickerson
- Department of Genome Sciences, University of Washington, Seattle, Washington, United States of America
- Northwest Genomics Center, Seattle, Washington, United States of America
- Brotman Baty Institute, Seattle, Washington, United States of America
| | - Soren Germer
- New York Genome Center, New York, New York, United States of America
| | - Jun Ding
- Human Statistical Genetics Unit, Laboratory of Genetics and Genomics, National Institute on Aging, National Institutes of Health, Bethesda, Maryland, United States of America
| | - David E. Lanfear
- Center for Individualized and Genomic Medicine Research (CIGMA), Department of Internal Medicine, Henry Ford Health System, Detroit, Michigan, United States of America
| | - Frank Gilliland
- Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - W. James Gauderman
- Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Rajesh Kumar
- Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States of America
| | - David J. Erle
- Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
- Lung Biology Center and UCSF CoLabs, University of California San Francisco, San Francisco, California, United States of America
| | - Fernando Martinez
- Arizona Respiratory Center and Department of Pediatrics, University of Arizona, Tucson, Arizona, United States of America
| | - Hakon Hakonarson
- Center for Applied Genomics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Esteban G. Burchard
- Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
- Department of Bioengineering & Therapeutic Sciences, University of California San Francisco, San Francisco, California, United States of America
| | - L. Keoki Williams
- Center for Individualized and Genomic Medicine Research (CIGMA), Department of Internal Medicine, Henry Ford Health System, Detroit, Michigan, United States of America
- * E-mail:
| |
Collapse
|
45
|
Rovcanin B, Jancic J, Pajic J, Rovcanin M, Samardzic J, Djuric V, Nikolic B, Ivancevic N, Novakovic I, Kostic V. Oxidative Stress Profile in Genetically Confirmed Cases of Leber's Hereditary Optic Neuropathy. J Mol Neurosci 2020; 71:1070-1081. [PMID: 33095398 DOI: 10.1007/s12031-020-01729-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Accepted: 10/06/2020] [Indexed: 10/23/2022]
Abstract
The mechanisms of the complex pathophysiology of Leber's hereditary optic neuropathy (LHON) are still insufficiently clarified. The role of oxidative stress as an etiological factor has been proposed and demonstrated in vitro, but without conclusive data that rely on clinical samples. The aim of the study was to evaluate and characterize the existence of oxidative stress in the plasma of LHON patients and healthy individuals. Whole mitochondrial genome sequencing has been performed in order to identify primary LHON mutations. For the assessment of oxidative stress, the following biomarkers were determined in plasma: total oxidant status (TOS), total antioxidant status (TAS), and oxidative stress index (OSI), while oxidative damage of cellular proteins was estimated by quantifying advanced oxidation protein products (AOPP). All three primary LHON mutations (m.3460G > A, m.11778G > A and m.14484 T > C) were identified as a genetic cause of the disease, where the most prevalent one was m.11778G > A. LHON patients have a highly significant increase of TOS and a marked decrease of TAS levels, which suggests the existence of substantial oxidative stress. OSI is high in LHON patients, which definitely implies the presence of redox imbalance. Elevated level of AOPP in LHON patients refers to the significant deleterious effects of oxidative stress on cellular proteins. Oxidative stress parameters do not significantly differ between LHON individuals with different primary mutations. Both symptomatic and asymptomatic LHON patients have an augmented level of oxidative stress which suggests that primary mutations exhibit a pro-oxidative phenotype. Gender and smoking habit significantly influence examined biochemical parameters when LHON patients are compared with the control group. Different mitochondrial haplogroups are characterized by altered levels of OSI in LHON group. The absence of physiological correlations between redox parameters reflects the deregulation of homeostatic oxidative/antioxidative balance in LHON patients. This is the greatest series of LHON patients that were evaluated for oxidative stress and the first case-controlled study that evaluated TOS, TAS, OSI, and AOPP and their influence on disease phenotype. It is evident that the presence of oxidative stress represents an important pathophysiological event in LHON and that it could potentially serve as a circulatory biomarker for a therapy efficacy understanding.
Collapse
Affiliation(s)
- Branislav Rovcanin
- Center for Endocrine Surgery, Clinical Center of Serbia, Faculty of Medicine, University of Belgrade, Koste Todorovica 8, 11000, Belgrade, Serbia. .,Center for Endocrine Surgery, Clinical Center of Serbia, Faculty of Medicine, University of Belgrade, Koste Todorovica 8, 11000, Belgrade, Serbia.
| | - Jasna Jancic
- Center for Endocrine Surgery, Clinical Center of Serbia, Faculty of Medicine, University of Belgrade, Koste Todorovica 8, 11000, Belgrade, Serbia.,Center for Endocrine Surgery, Clinical Center of Serbia, Faculty of Medicine, University of Belgrade, Koste Todorovica 8, 11000, Belgrade, Serbia.,Clinic of Neurology and Psychiatry for Children and Youth, Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Jelena Pajic
- Radiation Protection Department, Radiation Protection Center, Serbian Institute of Occupational Health Dr Dragomir Karajovic, Belgrade, Serbia
| | - Marija Rovcanin
- The Obstetrics and Gynecology Clinic Narodni Front, Belgrade, Serbia
| | - Janko Samardzic
- Institute of Pharmacology, Clinical Pharmacology and Toxicology, Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Vesna Djuric
- Clinic of Neurology and Psychiatry for Children and Youth, Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Blazo Nikolic
- Clinic of Neurology and Psychiatry for Children and Youth, Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Nikola Ivancevic
- Clinic of Neurology and Psychiatry for Children and Youth, Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Ivana Novakovic
- Faculty of Medicine, Institute for Human Genetics, University of Belgrade, Belgrade, Serbia
| | - Vladimir Kostic
- Clinic of Neurology, Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| |
Collapse
|
46
|
Gamulescu MA. [Gender medicine in ophthalmology : The "small difference" between women and men]. Ophthalmologe 2020; 117:831-842. [PMID: 32699941 DOI: 10.1007/s00347-020-01174-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Gender-specific or sex-specific medicine is part of "personalized" medicine. After differences in heart diseases between women and men were first identified and increasingly published in the field of cardiology since the 1980s, differences between the sexes have also become the focus of interest in other disciplines. Immunological and hormonal aspects indicate significant differences, e.g. in the severity of the disease or the response to treatment. Even in ophthalmology epidemiological differences in some diseases are known but so far these do not lead to a different approach in the practical treatment of patients. This CME article aims to raise awareness of gender medicine also in the field of ophthalmology and at the same time to promote understanding of these differences by presenting the fundamental differences between the sexes.
Collapse
Affiliation(s)
- M-A Gamulescu
- Klinik und Poliklinik für Augenheilkunde, Universitätsklinikum Regensburg, Franz-Josef-Strauss Allee 11, 93053, Regensburg, Deutschland.
| |
Collapse
|
47
|
Uittenbogaard M, Chiaramello A. Maternally inherited mitochondrial respiratory disorders: from pathogenetic principles to therapeutic implications. Mol Genet Metab 2020; 131:38-52. [PMID: 32624334 PMCID: PMC7749081 DOI: 10.1016/j.ymgme.2020.06.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 06/22/2020] [Accepted: 06/23/2020] [Indexed: 01/19/2023]
Abstract
Maternally inherited mitochondrial respiratory disorders are rare, progressive, and multi-systemic diseases that remain intractable, with no effective therapeutic interventions. Patients share a defective oxidative phosphorylation pathway responsible for mitochondrial ATP synthesis, in most cases due to pathogenic mitochondrial variants transmitted from mother to child or to a rare de novo mutation or large-scale deletion of the mitochondrial genome. The clinical diagnosis of these mitochondrial diseases is difficult due to exceptionally high clinical variability, while their genetic diagnosis has improved with the advent of next-generation sequencing. The mechanisms regulating the penetrance of the mitochondrial variants remain unresolved with the patient's nuclear background, epigenomic regulation, heteroplasmy, mitochondrial haplogroups, and environmental factors thought to act as rheostats. The lack of animal models mimicking the phenotypic manifestations of these disorders has hampered efforts toward curative therapies. Patient-derived cellular paradigms provide alternative models for elucidating the pathogenic mechanisms and screening pharmacological small molecules to enhance mitochondrial function. Recent progress has been made in designing promising approaches to curtail the negative impact of dysfunctional mitochondria and alleviate clinical symptoms: 1) boosting mitochondrial biogenesis; 2) shifting heteroplasmy; 3) reprogramming metabolism; and 4) administering hypoxia-based treatment. Here, we discuss their varying efficacies and limitations and provide an outlook on their therapeutic potential and clinical application.
Collapse
Affiliation(s)
- Martine Uittenbogaard
- George Washington University School of Medicine and Health Sciences, Department of Anatomy and Cell Biology, 2300 I Street N.W., Washington, DC 20037, USA
| | - Anne Chiaramello
- George Washington University School of Medicine and Health Sciences, Department of Anatomy and Cell Biology, 2300 I Street N.W., Washington, DC 20037, USA.
| |
Collapse
|
48
|
Rozen TD. Can the effects of the mitochondrial DNA mutations found in Leber’s hereditary optic neuropathy be protective against the development of cluster headache in smokers? CEPHALALGIA REPORTS 2020. [DOI: 10.1177/2515816320939571] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Is it possible that some mitochondrial DNA (mtDNA) mutations enhance the risk of developing a headache disorder while other mutations actually confer a protective effect? Mitochondrial disorders have been linked to migraine but very rarely to cluster headache (CH). The true pathogenesis of CH is unknown but a linkage to cigarette smoking is irrefutable. Leber’s hereditary optic neuropathy is a syndrome of bilateral vision loss that typically manifests in a patient’s 20s and 30s, is male predominant, and its sufferers are heavy smokers and heavy drinkers. Tobacco exposure is so linked to the condition that only smokers appear to develop vision loss while nonsmokers remain unaffected carriers of their mutations. In essence, the Leber’s hereditary optic neuropathy population is the CH population but at present there have been no reported cases of CH in this mitochondrial subgroup. Thus, could the effects of the mtDNA mutations found in Leber’s hereditary optic neuropathy, which involve complex I of the electron transport chain, actually confer a protective effect against the development of CH? This article will delve into this theory.
Collapse
Affiliation(s)
- Todd D Rozen
- Department of Neurology, Mayo Clinic Florida, Jacksonville, FL, USA
| |
Collapse
|
49
|
OXPHOS bioenergetic compensation does not explain disease penetrance in Leber hereditary optic neuropathy. Mitochondrion 2020; 54:113-121. [PMID: 32687992 DOI: 10.1016/j.mito.2020.07.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 04/24/2020] [Accepted: 07/14/2020] [Indexed: 11/23/2022]
Abstract
Leber hereditary optic neuropathy (LHON) is one of the most common primary mitochondrial diseases. It is caused by point mutations in mitochondrial DNA (mtDNA) genes and in some cases, it can result in irreversible vision loss, primarily in young men. It is currently unknown why LHON mutations affect only some carriers and whether bioenergetic compensation enables unaffected carriers to overcome mitochondrial impairment and preserve cellular function. Here, we conducted bioenergetic metabolic assays and RNA sequencing to address this question using male-only, age-matched, m.11778G > A lymphoblasts and primary fibroblasts from both unaffected carriers and affected individuals. Our work indicates that OXPHOS bioenergetic compensation in LHON peripheral cells does not explain disease phenotype. We show that complex I impairment is similar in cells from unaffected carrier and affected patients, despite a transcriptional downregulation of metabolic pathways including glycolysis in affected cells relative to carriers detected by RNA sequencing. Although we did not detect OXPHOS bioenergetic compensation in carrier cells under basal conditions, our results indicate that cells from affected patients suffer a growth impairment under metabolic challenge compared to carrier cells, which were unaffected by metabolic challenge. If recapitulated in retinal ganglion cells, decreased susceptibility to metabolic challenge in unaffected carriers may help preserve metabolic homeostasis in the face of the mitochondrial complex I bioenergetic defect.
Collapse
|
50
|
La Morgia C, Maresca A, Caporali L, Valentino ML, Carelli V. Mitochondrial diseases in adults. J Intern Med 2020; 287:592-608. [PMID: 32463135 DOI: 10.1111/joim.13064] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 02/07/2020] [Accepted: 02/21/2020] [Indexed: 02/07/2023]
Abstract
Mitochondrial medicine is a field that expanded exponentially in the last 30 years. Individually rare, mitochondrial diseases as a whole are probably the most frequent genetic disorder in adults. The complexity of their genotype-phenotype correlation, in terms of penetrance and clinical expressivity, natural history and diagnostic algorithm derives from the dual genetic determination. In fact, in addition to the about 1.500 genes encoding mitochondrial proteins that reside in the nuclear genome (nDNA), we have the 13 proteins encoded by the mitochondrial genome (mtDNA), for which 22 specific tRNAs and 2 rRNAs are also needed. Thus, besides Mendelian genetics, we need to consider all peculiarities of how mtDNA is inherited, maintained and expressed to fully understand the pathogenic mechanisms of these disorders. Yet, from the initial restriction to the narrow field of oxidative phosphorylation dysfunction, the landscape of mitochondrial functions impinging on cellular homeostasis, driving life and death, is impressively enlarged. Finally, from the clinical standpoint, starting from the neuromuscular field, where brain and skeletal muscle were the primary targets of mitochondrial dysfunction as energy-dependent tissues, after three decades virtually any subspecialty of medicine is now involved. We will summarize the key clinical pictures and pathogenic mechanisms of mitochondrial diseases in adults.
Collapse
Affiliation(s)
- C La Morgia
- From the, Dipartimento di Scienze Biomediche e Neuromotorie, Università di Bologna, Bologna, Italy.,IRCCS Istituto delle Scienze Neurologiche di Bologna, UOC Clinica Neurologica, Bologna, Italy
| | - A Maresca
- IRCCS Istituto delle Scienze Neurologiche di Bologna, UOC Clinica Neurologica, Bologna, Italy
| | - L Caporali
- IRCCS Istituto delle Scienze Neurologiche di Bologna, UOC Clinica Neurologica, Bologna, Italy
| | - M L Valentino
- From the, Dipartimento di Scienze Biomediche e Neuromotorie, Università di Bologna, Bologna, Italy.,IRCCS Istituto delle Scienze Neurologiche di Bologna, UOC Clinica Neurologica, Bologna, Italy
| | - V Carelli
- From the, Dipartimento di Scienze Biomediche e Neuromotorie, Università di Bologna, Bologna, Italy.,IRCCS Istituto delle Scienze Neurologiche di Bologna, UOC Clinica Neurologica, Bologna, Italy
| |
Collapse
|