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Accessory Subunits of the Matrix Arm of Mitochondrial Complex I with a Focus on Subunit NDUFS4 and Its Role in Complex I Function and Assembly. Life (Basel) 2021; 11:life11050455. [PMID: 34069703 PMCID: PMC8161149 DOI: 10.3390/life11050455] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Revised: 05/13/2021] [Accepted: 05/14/2021] [Indexed: 12/19/2022] Open
Abstract
NADH:ubiquinone-oxidoreductase (complex I) is the largest membrane protein complex of the respiratory chain. Complex I couples electron transfer to vectorial proton translocation across the inner mitochondrial membrane. The L shaped structure of complex I is divided into a membrane arm and a matrix arm. Fourteen central subunits are conserved throughout species, while some 30 accessory subunits are typically found in eukaryotes. Complex I dysfunction is associated with mutations in the nuclear and mitochondrial genome, resulting in a broad spectrum of neuromuscular and neurodegenerative diseases. Accessory subunit NDUFS4 in the matrix arm is a hot spot for mutations causing Leigh or Leigh-like syndrome. In this review, we focus on accessory subunits of the matrix arm and discuss recent reports on the function of accessory subunit NDUFS4 and its interplay with NDUFS6, NDUFA12, and assembly factor NDUFAF2 in complex I assembly.
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Grange RMH, Sharma R, Shah H, Reinstadler B, Goldberger O, Cooper MK, Nakagawa A, Miyazaki Y, Hindle AG, Batten AJ, Wojtkiewicz GR, Schleifer G, Bagchi A, Marutani E, Malhotra R, Bloch DB, Ichinose F, Mootha VK, Zapol WM. Hypoxia ameliorates brain hyperoxia and NAD + deficiency in a murine model of Leigh syndrome. Mol Genet Metab 2021; 133:83-93. [PMID: 33752971 PMCID: PMC8489256 DOI: 10.1016/j.ymgme.2021.03.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 03/07/2021] [Accepted: 03/07/2021] [Indexed: 11/24/2022]
Abstract
Leigh syndrome is a severe mitochondrial neurodegenerative disease with no effective treatment. In the Ndufs4-/- mouse model of Leigh syndrome, continuously breathing 11% O2 (hypoxia) prevents neurodegeneration and leads to a dramatic extension (~5-fold) in lifespan. We investigated the effect of hypoxia on the brain metabolism of Ndufs4-/- mice by studying blood gas tensions and metabolite levels in simultaneously sampled arterial and cerebral internal jugular venous (IJV) blood. Relatively healthy Ndufs4-/- and wildtype (WT) mice breathing air until postnatal age ~38 d were compared to Ndufs4-/- and WT mice breathing air until ~38 days old followed by 4-weeks of breathing 11% O2. Compared to WT control mice, Ndufs4-/- mice breathing air have reduced brain O2 consumption as evidenced by an elevated partial pressure of O2 in IJV blood (PijvO2) despite a normal PO2 in arterial blood, and higher lactate/pyruvate (L/P) ratios in IJV plasma revealed by metabolic profiling. In Ndufs4-/- mice, hypoxia treatment normalized the cerebral venous PijvO2 and L/P ratios, and decreased levels of nicotinate in IJV plasma. Brain concentrations of nicotinamide adenine dinucleotide (NAD+) were lower in Ndufs4-/- mice breathing air than in WT mice, but preserved at WT levels with hypoxia treatment. Although mild hypoxia (17% O2) has been shown to be an ineffective therapy for Ndufs4-/- mice, we find that when combined with nicotinic acid supplementation it provides a modest improvement in neurodegeneration and lifespan. Therapies targeting both brain hyperoxia and NAD+ deficiency may hold promise for treating Leigh syndrome.
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Affiliation(s)
- Robert M H Grange
- Anesthesia Center for Critical Care Research, Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Rohit Sharma
- Howard Hughes Medical Institute and Department of Molecular Biology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Hardik Shah
- Howard Hughes Medical Institute and Department of Molecular Biology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Bryn Reinstadler
- Howard Hughes Medical Institute and Department of Molecular Biology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Olga Goldberger
- Howard Hughes Medical Institute and Department of Molecular Biology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Marissa K Cooper
- Anesthesia Center for Critical Care Research, Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Akito Nakagawa
- Anesthesia Center for Critical Care Research, Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Yusuke Miyazaki
- Anesthesia Center for Critical Care Research, Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Allyson G Hindle
- School of Life Sciences, University of Nevada Las Vegas, Las Vegas, NV, USA
| | - Annabelle J Batten
- Anesthesia Center for Critical Care Research, Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Gregory R Wojtkiewicz
- Center for Systems Biology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Grigorij Schleifer
- Anesthesia Center for Critical Care Research, Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Aranya Bagchi
- Anesthesia Center for Critical Care Research, Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Eizo Marutani
- Anesthesia Center for Critical Care Research, Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Rajeev Malhotra
- Cardiology Division and Cardiovascular Research Center, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Donald B Bloch
- Anesthesia Center for Critical Care Research, Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA; Division of Rheumatology, Allergy and Immunology, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Fumito Ichinose
- Anesthesia Center for Critical Care Research, Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Vamsi K Mootha
- Howard Hughes Medical Institute and Department of Molecular Biology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
| | - Warren M Zapol
- Anesthesia Center for Critical Care Research, Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
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53
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Bernardi P. Looking Back to the Future of Mitochondrial Research. Front Physiol 2021; 12:682467. [PMID: 33995132 PMCID: PMC8119648 DOI: 10.3389/fphys.2021.682467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 04/12/2021] [Indexed: 12/03/2022] Open
Affiliation(s)
- Paolo Bernardi
- Department of Biomedical Sciences, University of Padova, Padova, Italy
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54
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Inak G, Rybak-Wolf A, Lisowski P, Pentimalli TM, Jüttner R, Glažar P, Uppal K, Bottani E, Brunetti D, Secker C, Zink A, Meierhofer D, Henke MT, Dey M, Ciptasari U, Mlody B, Hahn T, Berruezo-Llacuna M, Karaiskos N, Di Virgilio M, Mayr JA, Wortmann SB, Priller J, Gotthardt M, Jones DP, Mayatepek E, Stenzel W, Diecke S, Kühn R, Wanker EE, Rajewsky N, Schuelke M, Prigione A. Defective metabolic programming impairs early neuronal morphogenesis in neural cultures and an organoid model of Leigh syndrome. Nat Commun 2021; 12:1929. [PMID: 33771987 PMCID: PMC7997884 DOI: 10.1038/s41467-021-22117-z] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 03/01/2021] [Indexed: 12/12/2022] Open
Abstract
Leigh syndrome (LS) is a severe manifestation of mitochondrial disease in children and is currently incurable. The lack of effective models hampers our understanding of the mechanisms underlying the neuronal pathology of LS. Using patient-derived induced pluripotent stem cells and CRISPR/Cas9 engineering, we developed a human model of LS caused by mutations in the complex IV assembly gene SURF1. Single-cell RNA-sequencing and multi-omics analysis revealed compromised neuronal morphogenesis in mutant neural cultures and brain organoids. The defects emerged at the level of neural progenitor cells (NPCs), which retained a glycolytic proliferative state that failed to instruct neuronal morphogenesis. LS NPCs carrying mutations in the complex I gene NDUFS4 recapitulated morphogenesis defects. SURF1 gene augmentation and PGC1A induction via bezafibrate treatment supported the metabolic programming of LS NPCs, leading to restored neuronal morphogenesis. Our findings provide mechanistic insights and suggest potential interventional strategies for a rare mitochondrial disease.
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Affiliation(s)
- Gizem Inak
- Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany
- Department of General Pediatrics, Neonatology and Pediatric Cardiology, Duesseldorf University Hospital, Medical Faculty, Heinrich Heine University, Duesseldorf, Germany
| | - Agnieszka Rybak-Wolf
- Berlin Institute for Medical Systems Biology (BIMSB), Max Delbrück Center for Molecular Medicine (MDC), Hannoversche Str 28, 10115, Berlin, Germany
| | - Pawel Lisowski
- Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany
- Department of General Pediatrics, Neonatology and Pediatric Cardiology, Duesseldorf University Hospital, Medical Faculty, Heinrich Heine University, Duesseldorf, Germany
- Institute of Genetics and Animal Biotechnology, Polish Academy of Sciences, Jastrzebiec, n/Warsaw, Magdalenka, Poland
| | - Tancredi M Pentimalli
- Berlin Institute for Medical Systems Biology (BIMSB), Max Delbrück Center for Molecular Medicine (MDC), Hannoversche Str 28, 10115, Berlin, Germany
| | - René Jüttner
- Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany
| | - Petar Glažar
- Berlin Institute for Medical Systems Biology (BIMSB), Max Delbrück Center for Molecular Medicine (MDC), Hannoversche Str 28, 10115, Berlin, Germany
| | | | - Emanuela Bottani
- Department of Diagnostics and Public Health, University of Verona, Verona, Italy
| | - Dario Brunetti
- Mitochondrial Medicine Laboratory, Department of Medical Biotechnology and Translational Medicine, University of Milan, Milan, Italy
- Unit of Medical Genetics and Neurogenetics Fondazione IRCCS Istituto Neurologico "Carlo Besta", Milan, Italy
| | - Christopher Secker
- Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany
- Charité - Universitätsmedizin Berlin, Department of Neurology, Berlin, Germany
| | - Annika Zink
- Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany
- Department of General Pediatrics, Neonatology and Pediatric Cardiology, Duesseldorf University Hospital, Medical Faculty, Heinrich Heine University, Duesseldorf, Germany
- Charité - Universitätsmedizin Berlin, Department of Neuropsychiatry, Berlin, Germany
| | | | - Marie-Thérèse Henke
- Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany
- Charité - Universitätsmedizin Berlin, Department of Neuropediatrics, Berlin, Germany
| | - Monishita Dey
- Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany
| | - Ummi Ciptasari
- Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany
| | - Barbara Mlody
- Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany
| | - Tobias Hahn
- Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany
| | | | - Nikos Karaiskos
- Berlin Institute for Medical Systems Biology (BIMSB), Max Delbrück Center for Molecular Medicine (MDC), Hannoversche Str 28, 10115, Berlin, Germany
| | | | - Johannes A Mayr
- University Children's Hospital, Paracelsus Medical University (PMU), Salzburg, Austria
| | - Saskia B Wortmann
- University Children's Hospital, Paracelsus Medical University (PMU), Salzburg, Austria
- Radboud Center for Mitochondrial Medicine, Department of Pediatrics, Amalia Children's Hospital, Radboudumc, Nijmegen, The Netherlands
| | - Josef Priller
- Charité - Universitätsmedizin Berlin, Department of Neuropsychiatry, Berlin, Germany
- University of Edinburgh and UK DRI, Edinburgh, UK
- Department of Psychiatry and Psychotherapy, Klinikum rechts der Isar, Technical University Munich, Munich, Germany
| | | | | | - Ertan Mayatepek
- Department of General Pediatrics, Neonatology and Pediatric Cardiology, Duesseldorf University Hospital, Medical Faculty, Heinrich Heine University, Duesseldorf, Germany
| | - Werner Stenzel
- Charité - Universitätsmedizin, Department of Neuropathology, Berlin, Germany
| | - Sebastian Diecke
- Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany
- Berlin Institute of Health (BIH), Berlin, Germany
| | - Ralf Kühn
- Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany
| | - Erich E Wanker
- Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany
| | - Nikolaus Rajewsky
- Berlin Institute for Medical Systems Biology (BIMSB), Max Delbrück Center for Molecular Medicine (MDC), Hannoversche Str 28, 10115, Berlin, Germany.
| | - Markus Schuelke
- Charité - Universitätsmedizin Berlin, Department of Neuropediatrics, Berlin, Germany.
- NeuroCure Clinical Research Center, Berlin, Germany.
| | - Alessandro Prigione
- Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany.
- Department of General Pediatrics, Neonatology and Pediatric Cardiology, Duesseldorf University Hospital, Medical Faculty, Heinrich Heine University, Duesseldorf, Germany.
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55
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Generation of Reactive Oxygen Species by Mitochondria. Antioxidants (Basel) 2021; 10:antiox10030415. [PMID: 33803273 PMCID: PMC8001687 DOI: 10.3390/antiox10030415] [Citation(s) in RCA: 141] [Impact Index Per Article: 47.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 02/28/2021] [Accepted: 03/01/2021] [Indexed: 12/15/2022] Open
Abstract
Reactive oxygen species (ROS) are series of chemical products originated from one or several electron reductions of oxygen. ROS are involved in physiology and disease and can also be both cause and consequence of many biological scenarios. Mitochondria are the main source of ROS in the cell and, particularly, the enzymes in the electron transport chain are the major contributors to this phenomenon. Here, we comprehensively review the modes by which ROS are produced by mitochondria at a molecular level of detail, discuss recent advances in the field involving signalling and disease, and the involvement of supercomplexes in these mechanisms. Given the importance of mitochondrial ROS, we also provide a schematic guide aimed to help in deciphering the mechanisms involved in their production in a variety of physiological and pathological settings.
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56
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Glancy B, Kane DA, Kavazis AN, Goodwin ML, Willis WT, Gladden LB. Mitochondrial lactate metabolism: history and implications for exercise and disease. J Physiol 2021; 599:863-888. [PMID: 32358865 PMCID: PMC8439166 DOI: 10.1113/jp278930] [Citation(s) in RCA: 89] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 03/25/2020] [Indexed: 12/31/2022] Open
Abstract
Mitochondrial structures were probably observed microscopically in the 1840s, but the idea of oxidative phosphorylation (OXPHOS) within mitochondria did not appear until the 1930s. The foundation for research into energetics arose from Meyerhof's experiments on oxidation of lactate in isolated muscles recovering from electrical contractions in an O2 atmosphere. Today, we know that mitochondria are actually reticula and that the energy released from electron pairs being passed along the electron transport chain from NADH to O2 generates a membrane potential and pH gradient of protons that can enter the molecular machine of ATP synthase to resynthesize ATP. Lactate stands at the crossroads of glycolytic and oxidative energy metabolism. Based on reported research and our own modelling in silico, we contend that lactate is not directly oxidized in the mitochondrial matrix. Instead, the interim glycolytic products (pyruvate and NADH) are held in cytosolic equilibrium with the products of the lactate dehydrogenase (LDH) reaction and the intermediates of the malate-aspartate and glycerol 3-phosphate shuttles. This equilibrium supplies the glycolytic products to the mitochondrial matrix for OXPHOS. LDH in the mitochondrial matrix is not compatible with the cytoplasmic/matrix redox gradient; its presence would drain matrix reducing power and substantially dissipate the proton motive force. OXPHOS requires O2 as the final electron acceptor, but O2 supply is sufficient in most situations, including exercise and often acute illness. Recent studies suggest that atmospheric normoxia may constitute a cellular hyperoxia in mitochondrial disease. As research proceeds appropriate oxygenation levels should be carefully considered.
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Affiliation(s)
- Brian Glancy
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
- National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Daniel A. Kane
- Department of Human Kinetics, St. Francis Xavier University, NS B2G 2W5, Antigonish, Canada
| | | | - Matthew L. Goodwin
- Department of Orthopaedic Surgery, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Wayne T. Willis
- College of Medicine, Department of Medicine, University of Arizona, Tucson, AZ 85724-5099, USA
| | - L. Bruce Gladden
- School of Kinesiology, Auburn University, Auburn, AL 36849-5323, USA
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57
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Miller HC, Louw R, Mereis M, Venter G, Boshoff JD, Mienie L, van Reenen M, Venter M, Lindeque JZ, Domínguez-Martínez A, Quintana A, van der Westhuizen FH. Metallothionein 1 Overexpression Does Not Protect Against Mitochondrial Disease Pathology in Ndufs4 Knockout Mice. Mol Neurobiol 2021; 58:243-262. [PMID: 32918239 DOI: 10.1007/s12035-020-02121-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 09/05/2020] [Indexed: 01/24/2023]
Abstract
Mitochondrial diseases (MD), such as Leigh syndrome (LS), present with severe neurological and muscular phenotypes in patients, but have no known cure and limited treatment options. Based on their neuroprotective effects against other neurodegenerative diseases in vivo and their positive impact as an antioxidant against complex I deficiency in vitro, we investigated the potential protective effect of metallothioneins (MTs) in an Ndufs4 knockout mouse model (with a very similar phenotype to LS) crossed with an Mt1 overexpressing mouse model (TgMt1). Despite subtle reductions in the expression of neuroinflammatory markers GFAP and IBA1 in the vestibular nucleus and hippocampus, we found no improvement in survival, growth, locomotor activity, balance, or motor coordination in the Mt1 overexpressing Ndufs4-/- mice. Furthermore, at a cellular level, no differences were detected in the metabolomics profile or gene expression of selected one-carbon metabolism and oxidative stress genes, performed in the brain and quadriceps, nor in the ROS levels of macrophages derived from these mice. Considering these outcomes, we conclude that MT1, in general, does not protect against the impaired motor activity or improve survival in these complex I-deficient mice. The unexpected absence of increased oxidative stress and metabolic redox imbalance in this MD model may explain these observations. However, tissue-specific observations such as the mildly reduced inflammation in the hippocampus and vestibular nucleus, as well as differential MT1 expression in these tissues, may yet reveal a tissue- or cell-specific role for MTs in these mice.
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Affiliation(s)
- Hayley Christy Miller
- Human Metabolomics, Faculty of Natural and Agricultural Sciences, North-West University (Potchefstroom Campus), Private Bag X6001, Potchefstroom, South Africa
| | - Roan Louw
- Human Metabolomics, Faculty of Natural and Agricultural Sciences, North-West University (Potchefstroom Campus), Private Bag X6001, Potchefstroom, South Africa
| | - Michelle Mereis
- Human Metabolomics, Faculty of Natural and Agricultural Sciences, North-West University (Potchefstroom Campus), Private Bag X6001, Potchefstroom, South Africa
| | - Gerda Venter
- Human Metabolomics, Faculty of Natural and Agricultural Sciences, North-West University (Potchefstroom Campus), Private Bag X6001, Potchefstroom, South Africa
| | - John-Drew Boshoff
- Human Metabolomics, Faculty of Natural and Agricultural Sciences, North-West University (Potchefstroom Campus), Private Bag X6001, Potchefstroom, South Africa
| | - Liesel Mienie
- Human Metabolomics, Faculty of Natural and Agricultural Sciences, North-West University (Potchefstroom Campus), Private Bag X6001, Potchefstroom, South Africa
| | - Mari van Reenen
- Human Metabolomics, Faculty of Natural and Agricultural Sciences, North-West University (Potchefstroom Campus), Private Bag X6001, Potchefstroom, South Africa
| | - Marianne Venter
- Human Metabolomics, Faculty of Natural and Agricultural Sciences, North-West University (Potchefstroom Campus), Private Bag X6001, Potchefstroom, South Africa
| | - Jeremie Zander Lindeque
- Human Metabolomics, Faculty of Natural and Agricultural Sciences, North-West University (Potchefstroom Campus), Private Bag X6001, Potchefstroom, South Africa
| | - Adán Domínguez-Martínez
- Institut de Neurociències i Departament de Biologia Cel·lular, Fisiologia i Immunologia, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Albert Quintana
- Institut de Neurociències i Departament de Biologia Cel·lular, Fisiologia i Immunologia, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Francois Hendrikus van der Westhuizen
- Human Metabolomics, Faculty of Natural and Agricultural Sciences, North-West University (Potchefstroom Campus), Private Bag X6001, Potchefstroom, South Africa.
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58
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Koňaříková E, Marković A, Korandová Z, Houštěk J, Mráček T. Current progress in the therapeutic options for mitochondrial disorders. Physiol Res 2020; 69:967-994. [PMID: 33129249 PMCID: PMC8549882 DOI: 10.33549/physiolres.934529] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Accepted: 10/02/2020] [Indexed: 12/20/2022] Open
Abstract
Mitochondrial disorders manifest enormous genetic and clinical heterogeneity - they can appear at any age, present with various phenotypes affecting any organ, and display any mode of inheritance. What mitochondrial diseases do have in common, is impairment of respiratory chain activity, which is responsible for more than 90% of energy production within cells. While diagnostics of mitochondrial disorders has been accelerated by introducing Next-Generation Sequencing techniques in recent years, the treatment options are still very limited. For many patients only a supportive or symptomatic therapy is available at the moment. However, decades of basic and preclinical research have uncovered potential target points and numerous compounds or interventions are now subjects of clinical trials. In this review, we focus on current and emerging therapeutic approaches towards the treatment of mitochondrial disorders. We focus on small compounds, metabolic interference, such as endurance training or ketogenic diet and also on genomic approaches.
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Affiliation(s)
- E Koňaříková
- Laboratory of Bioenergetics, Institute of Physiology Czech Acad. Sci., Prague, Czech Republic. ,
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59
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Du M, Wei X, Xu P, Xie A, Zhou X, Yang Y, Li D, Lyu J, Fang H. A novel mitochondrial m.14430A>G (MT-ND6, p.W82R) variant causes complex I deficiency and mitochondrial Leigh syndrome. Clin Chem Lab Med 2020; 58:1809-1817. [PMID: 32432562 DOI: 10.1515/cclm-2020-0150] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 04/25/2020] [Indexed: 11/15/2022]
Abstract
Objectives Leigh syndrome (LS) is one of the most common mitochondrial diseases and has variable clinical symptoms. However, the genetic variant spectrum of this disease is incomplete. Methods Next-generation sequencing (NGS) was used to identify the m.14430A > G (p.W82R) variant in a patient with LS. The pathogenesis of this novel complex I (CI) variant was verified by determining the mitochondrial respiration, assembly of CI, ATP, MMP and lactate production, and cell growth rate in cybrids with and without this variant. Results A novel m.14430A > G (p.W82R) variant in the NADH dehydrogenase 6 (ND6) gene was identified in the patient; the mutant loads of m.14430A > G (p.W82R) in the patient were much higher than those in his mother. Although the transmitochondrial cybrid-based study showed that mitochondrial CI assembly remains unaffected in cells with the m.14430G variant, control cells had significantly higher endogenous and CI-dependent mitochondrial respiration than mutant cells. Accordingly, mutant cells had a lower ATP, MMP and higher extracellular lactate production than control cells. Notably, mutant cells had impaired growth in a galactose-containing medium when compared to wild-type cells. Conclusions A novel m.14430A > G (p.W82R) variant in the ND6 gene was identified from a patient suspected to have LS, and this variant impaired mitochondrial respiration by decreasing the activity of mitochondrial CI.
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Affiliation(s)
- Miaomiao Du
- College of Laboratory Medicine, Hangzhou Medical College, Hangzhou, Zhejiang, P.R. China.,Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial, Key Laboratory of Medical Genetics, College of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Chashan, Wenzhou, Zhejiang, P.R. China
| | - Xiujuan Wei
- Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial, Key Laboratory of Medical Genetics, College of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Chashan, Wenzhou, Zhejiang, P.R. China
| | - Pu Xu
- Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial, Key Laboratory of Medical Genetics, College of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Chashan, Wenzhou, Zhejiang, P.R. China
| | - Anran Xie
- Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial, Key Laboratory of Medical Genetics, College of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Chashan, Wenzhou, Zhejiang, P.R. China
| | - Xiyue Zhou
- Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial, Key Laboratory of Medical Genetics, College of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Chashan, Wenzhou, Zhejiang, P.R. China
| | - Yanling Yang
- Department of Pediatrics, Peking University First Hospital, Beijing, P.R. China
| | - Dongxiao Li
- Henan Provincial Key Laboratory of Children's Genetics and Metabolic Diseases, Children's Hospital Affiliated to Zhengzhou University, Zhengzhou 450003, Henan, P.R. China
| | - Jianxin Lyu
- Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial, Key Laboratory of Medical Genetics, College of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Chashan, Wenzhou 325035, Zhejiang, P.R. China.,College of Laboratory Medicine, Hangzhou Medical College, Hangzhou 310053, Zhejiang, P.R. China
| | - Hezhi Fang
- Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial, Key Laboratory of Medical Genetics, College of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Chashan, Wenzhou 325035, Zhejiang, P.R. China
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Saldana-Caboverde A, Nissanka N, Garcia S, Lombès A, Diaz F. Hypoxia Promotes Mitochondrial Complex I Abundance via HIF-1α in Complex III and Complex IV Eficient Cells. Cells 2020; 9:cells9102197. [PMID: 33003371 PMCID: PMC7599499 DOI: 10.3390/cells9102197] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 09/18/2020] [Accepted: 09/21/2020] [Indexed: 11/16/2022] Open
Abstract
Murine fibroblasts deficient in mitochondria respiratory complexes III (CIII) and IV (CIV) produced by either the ablation of Uqcrfs1 (encoding for Rieske iron sulfur protein, RISP) or Cox10 (encoding for protoheme IX farnesyltransferase, COX10) genes, respectively, showed a pleiotropic effect in complex I (CI). Exposure to 1-5% oxygen increased the levels of CI in both RISP and COX10 KO fibroblasts. De novo assembly of the respiratory complexes occurred at a faster rate and to higher levels in 1% oxygen compared to normoxia in both RISP and COX10 KO fibroblasts. Hypoxia did not affect the levels of assembly of CIII in the COX10 KO fibroblasts nor abrogated the genetic defect impairing CIV assembly. Mitochondrial signaling involving reactive oxygen species (ROS) has been implicated as necessary for HIF-1α stabilization in hypoxia. We did not observe increased ROS production in hypoxia. Exposure to low oxygen levels stabilized HIF-1α and increased CI levels in RISP and COX10 KO fibroblasts. Knockdown of HIF-1α during hypoxic conditions abrogated the beneficial effect of hypoxia on the stability/assembly of CI. These findings demonstrate that oxygen and HIF-1α regulate the assembly of respiratory complexes.
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Affiliation(s)
- Amy Saldana-Caboverde
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL 33136, USA; (A.S.-C.); (N.N.); (S.G.)
| | - Nadee Nissanka
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL 33136, USA; (A.S.-C.); (N.N.); (S.G.)
| | - Sofia Garcia
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL 33136, USA; (A.S.-C.); (N.N.); (S.G.)
| | - Anne Lombès
- Institut Cochin, Unité U1016, INSERM, UMR 8104, CNRS, Université Paris 5, F-75014 Paris, France;
| | - Francisca Diaz
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL 33136, USA; (A.S.-C.); (N.N.); (S.G.)
- Correspondence: ; Tel.: +1-305-243-7489
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61
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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.
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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.
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Almannai M, El-Hattab AW, Ali M, Soler-Alfonso C, Scaglia F. Clinical trials in mitochondrial disorders, an update. Mol Genet Metab 2020; 131:1-13. [PMID: 33129691 PMCID: PMC7537630 DOI: 10.1016/j.ymgme.2020.10.002] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 10/02/2020] [Indexed: 12/11/2022]
Abstract
Mitochondrial disorders comprise a molecular and clinically diverse group of diseases that are associated with mitochondrial dysfunction leading to multi-organ disease. With recent advances in molecular technologies, the understanding of the pathomechanisms of a growing list of mitochondrial disorders has been greatly expanded. However, the therapeutic approaches for mitochondrial disorders have lagged behind with treatment options limited mainly to symptom specific therapies and supportive measures. There is an increasing number of clinical trials in mitochondrial disorders aiming for more specific and effective therapies. This review will cover different treatment modalities currently used in mitochondrial disorders, focusing on recent and ongoing clinical trials.
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Affiliation(s)
- Mohammed Almannai
- Section of Medical Genetics, Children's Hospital, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Ayman W El-Hattab
- Department of Clinical Sciences, College of Medicine, University of Sharjah, Sharjah, United Arab Emirates
| | - May Ali
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Claudia Soler-Alfonso
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA; Texas Children's Hospital, Houston, TX, USA
| | - Fernando Scaglia
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA; Texas Children's Hospital, Houston, TX, USA; Joint BCM-CUHK Center of Medical Genetics, Prince of Wales Hospital, Shatin, Hong Kong.
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63
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Mitochondrial dysfunction in GnRH neurons impaired GnRH production. Biochem Biophys Res Commun 2020; 530:329-335. [PMID: 32828307 DOI: 10.1016/j.bbrc.2020.07.090] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 07/18/2020] [Indexed: 12/25/2022]
Abstract
The onset establishment and maintenance of gonadotropin-releasing hormone (GnRH) secretion is an important phenomenon regulating pubertal development and reproduction. GnRH neurons as well as other neurons in the hypothalamus have high-energy demands and require a constant energy supply from their mitochondria machinery to maintain active functioning. However, the involvement of mitochondrial function in GnRH neurons is still unclear. In this study, we examined the role of NADH Dehydrogenase (Ubiquinone) Fe-S protein 4 (Ndufs4), a member of the mitochondrial complex 1, on GnRH neurons using Ndufs4-KO mice and Ndufs4-KO GT1-7 cells. Ndufs4 was highly expressed in GnRH neurons in the medial preoptic area (MPOA) and NPY/AgRP and POMC neurons in the arcuate (ARC) nucleus in WT mice. Conversely, there was a significant decrease in GnRH expression in MPOA and median eminence of Ndufs4-KO mice, followed by impaired peripheral endocrine system. In Ndufs4-KO GT1-7 cells, Gnrh1 expression was significantly decreased with or without stimulation with either kisspeptin or NGF, whereas, stimulation significantly increased Gnrh1 expression in control cells. In contrast, there was no difference in cell signaling activity including ERK and CREB as well as the expression of GPR54, TrkA and p75NTR, suggesting that Ndufs4 is involved in the transcriptional regulation system for GnRH production. These findings may be useful in understanding the mitochondrial function in GnRH neuron.
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64
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Mnatsakanyan N, Jonas EA. The new role of F 1F o ATP synthase in mitochondria-mediated neurodegeneration and neuroprotection. Exp Neurol 2020; 332:113400. [PMID: 32653453 DOI: 10.1016/j.expneurol.2020.113400] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 05/23/2020] [Accepted: 07/07/2020] [Indexed: 02/08/2023]
Abstract
The mitochondrial F1Fo ATP synthase is one of the most abundant proteins of the mitochondrial inner membrane, which catalyzes the final step of oxidative phosphorylation to synthesize ATP from ADP and Pi. ATP synthase uses the electrochemical gradient of protons (ΔμH+) across the mitochondrial inner membrane to synthesize ATP. Under certain pathophysiological conditions, ATP synthase can run in reverse to hydrolyze ATP and build the necessary ΔμH+ across the mitochondrial inner membrane. Tight coupling between these two processes, proton translocation and ATP synthesis, is achieved by the unique rotational mechanism of ATP synthase and is necessary for efficient cellular metabolism and cell survival. The uncoupling of these processes, dissipation of mitochondrial inner membrane potential, elevated levels of ROS, low matrix content of ATP in combination with other cellular malfunction trigger the opening of the mitochondrial permeability transition pore in the mitochondrial inner membrane. In this review we will discuss the new role of ATP synthase beyond oxidative phosphorylation. We will highlight its function as a unique regulator of cell life and death and as a key target in mitochondria-mediated neurodegeneration and neuroprotection.
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Affiliation(s)
- Nelli Mnatsakanyan
- Section of Endocrinology, Department of Internal Medicine, Yale University, New Haven, CT, USA.
| | - Elizabeth Ann Jonas
- Section of Endocrinology, Department of Internal Medicine, Yale University, New Haven, CT, USA
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65
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Baik AH, Jain IH. Turning the Oxygen Dial: Balancing the Highs and Lows. Trends Cell Biol 2020; 30:516-536. [PMID: 32386878 PMCID: PMC7391449 DOI: 10.1016/j.tcb.2020.04.005] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Revised: 04/02/2020] [Accepted: 04/08/2020] [Indexed: 02/06/2023]
Abstract
Oxygen is both vital and toxic to life. Molecular oxygen is the most used substrate in the human body and is required for several hundred diverse biochemical reactions. The discovery of the PHD-HIF-pVHL system revolutionized our fundamental understanding of oxygen sensing and cellular adaptations to hypoxia. It deepened our knowledge of the biochemical underpinnings of numerous diseases, ranging from anemia to cancer. Cellular dysfunction and tissue pathology can result from a mismatch of oxygen supply and demand. Recent work has shown that mitochondrial disease models display tissue hyperoxia and that disease pathology can be reversed by normalization of excess oxygen, suggesting that certain disease states can potentially be treated by modulating oxygen levels. In this review, we describe cellular and organismal mechanisms of oxygen sensing and adaptation. We provide a revitalized framework for understanding pathologies of too little or too much oxygen.
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Affiliation(s)
- Alan H Baik
- Department of Physiology, University of California, San Francisco, CA 94158, USA; Department of Medicine, Division of Cardiology, University of California, San Francisco, CA 94143, USA.
| | - Isha H Jain
- Department of Physiology, University of California, San Francisco, CA 94158, USA.
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66
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Viscomi C, Zeviani M. Strategies for fighting mitochondrial diseases. J Intern Med 2020; 287:665-684. [PMID: 32100338 DOI: 10.1111/joim.13046] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Revised: 11/10/2019] [Accepted: 01/24/2020] [Indexed: 12/19/2022]
Abstract
Mitochondrial diseases are extremely heterogeneous genetic conditions characterized by faulty oxidative phosphorylation (OXPHOS). OXPHOS deficiency can be the result of mutation in mtDNA genes, encoding either proteins (13 subunits of the mitochondrial complexes I, III, IV and V) or the tRNA and rRNA components of the in situ mtDNA translation. The remaining mitochondrial disease genes are in the nucleus, encoding proteins with a huge variety of functions, from structural subunits of the mitochondrial complexes, to factors involved in their formation and regulation, components of the mtDNA replication and expression machinery, biosynthetic enzymes for the biosynthesis or incorporation of prosthetic groups, components of the mitochondrial quality control and proteostasis, enzymes involved in the clearance of toxic compounds, factors involved in the formation of the lipid milieu, etc. These different functions represent potential targets for 'general' therapeutic interventions, as they may be adapted to a number of different mitochondrial conditions. This is in contrast with 'tailored', personalized therapeutic approaches, such as gene therapy, cell therapy and organ replacement, that can be useful only for individual conditions. This review will present the most recent concepts emerged from preclinical work and the attempts to translate them into the clinics. The common notion that mitochondrial disorders have no cure is currently challenged by a massive effort of scientists and clinicians, and we do expect that thanks to this intensive investigation work and tangible results for the development of strategies amenable to the treatment of patients with these tremendously difficult conditions are not so far away.
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Affiliation(s)
- C Viscomi
- From the, Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - M Zeviani
- Department of Neurosciences, University of Padova, Padova, Italy.,Venetian Institute of Molecular Medicine, Padova, Italy
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67
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Abstract
Mitochondrial disease presenting in childhood is characterized by clinical, biochemical and genetic complexity. Some children are affected by canonical syndromes, but the majority have nonclassical multisystemic disease presentations involving virtually any organ in the body. Each child has a unique constellation of clinical features and disease trajectory, leading to enormous challenges in diagnosis and management of these heterogeneous disorders. This review discusses the classical mitochondrial syndromes presenting most frequently in childhood and then presents an organ-based perspective including systems less frequently linked to mitochondrial disease, such as skin and hair abnormalities and immune dysfunction. An approach to diagnosis is then presented, encompassing clinical evaluation and biochemical, neuroimaging and genetic investigations, and emphasizing the problem of phenocopies. The impact of next-generation sequencing is discussed, together with the importance of functional validation of novel genetic variants never previously linked to mitochondrial disease. The review concludes with a brief discussion of currently available and emerging therapies. The field of mitochondrial medicine has made enormous strides in the last 30 years, with approaching 400 different genes across two genomes now linked to primary mitochondrial disease. However, many important questions remain unanswered, including the reasons for tissue specificity and variability of clinical presentation of individuals sharing identical gene defects, and a lack of disease-modifying therapies and biomarkers to monitor disease progression and/or response to treatment.
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Affiliation(s)
- S Rahman
- Mitochondrial Research Group, UCL Great Ormond Street Institute of Child Health, London, UK
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68
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Mick E, Titov DV, Skinner OS, Sharma R, Jourdain AA, Mootha VK. Distinct mitochondrial defects trigger the integrated stress response depending on the metabolic state of the cell. eLife 2020; 9:e49178. [PMID: 32463360 PMCID: PMC7255802 DOI: 10.7554/elife.49178] [Citation(s) in RCA: 130] [Impact Index Per Article: 32.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2019] [Accepted: 05/04/2020] [Indexed: 12/13/2022] Open
Abstract
Mitochondrial dysfunction is associated with activation of the integrated stress response (ISR) but the underlying triggers remain unclear. We systematically combined acute mitochondrial inhibitors with genetic tools for compartment-specific NADH oxidation to trace mechanisms linking different forms of mitochondrial dysfunction to the ISR in proliferating mouse myoblasts and in differentiated myotubes. In myoblasts, we find that impaired NADH oxidation upon electron transport chain (ETC) inhibition depletes asparagine, activating the ISR via the eIF2α kinase GCN2. In myotubes, however, impaired NADH oxidation following ETC inhibition neither depletes asparagine nor activates the ISR, reflecting an altered metabolic state. ATP synthase inhibition in myotubes triggers the ISR via a distinct mechanism related to mitochondrial inner-membrane hyperpolarization. Our work dispels the notion of a universal path linking mitochondrial dysfunction to the ISR, instead revealing multiple paths that depend both on the nature of the mitochondrial defect and on the metabolic state of the cell.
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Affiliation(s)
- Eran Mick
- Howard Hughes Medical Institute and Department of Molecular Biology, Massachusetts General HospitalBostonUnited States
- Broad InstituteCambridgeUnited States
- Department of Systems Biology, Harvard Medical SchoolBostonUnited States
| | - Denis V Titov
- Howard Hughes Medical Institute and Department of Molecular Biology, Massachusetts General HospitalBostonUnited States
- Broad InstituteCambridgeUnited States
- Department of Systems Biology, Harvard Medical SchoolBostonUnited States
| | - Owen S Skinner
- Howard Hughes Medical Institute and Department of Molecular Biology, Massachusetts General HospitalBostonUnited States
- Broad InstituteCambridgeUnited States
- Department of Systems Biology, Harvard Medical SchoolBostonUnited States
| | - Rohit Sharma
- Howard Hughes Medical Institute and Department of Molecular Biology, Massachusetts General HospitalBostonUnited States
- Broad InstituteCambridgeUnited States
- Department of Systems Biology, Harvard Medical SchoolBostonUnited States
| | - Alexis A Jourdain
- Howard Hughes Medical Institute and Department of Molecular Biology, Massachusetts General HospitalBostonUnited States
- Broad InstituteCambridgeUnited States
- Department of Systems Biology, Harvard Medical SchoolBostonUnited States
| | - Vamsi K Mootha
- Howard Hughes Medical Institute and Department of Molecular Biology, Massachusetts General HospitalBostonUnited States
- Broad InstituteCambridgeUnited States
- Department of Systems Biology, Harvard Medical SchoolBostonUnited States
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69
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Lee P, Chandel NS, Simon MC. Cellular adaptation to hypoxia through hypoxia inducible factors and beyond. Nat Rev Mol Cell Biol 2020; 21:268-283. [PMID: 32144406 PMCID: PMC7222024 DOI: 10.1038/s41580-020-0227-y] [Citation(s) in RCA: 606] [Impact Index Per Article: 151.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/12/2020] [Indexed: 02/06/2023]
Abstract
Molecular oxygen (O2) sustains intracellular bioenergetics and is consumed by numerous biochemical reactions, making it essential for most species on Earth. Accordingly, decreased oxygen concentration (hypoxia) is a major stressor that generally subverts life of aerobic species and is a prominent feature of pathological states encountered in bacterial infection, inflammation, wounds, cardiovascular defects and cancer. Therefore, key adaptive mechanisms to cope with hypoxia have evolved in mammals. Systemically, these adaptations include increased ventilation, cardiac output, blood vessel growth and circulating red blood cell numbers. On a cellular level, ATP-consuming reactions are suppressed, and metabolism is altered until oxygen homeostasis is restored. A critical question is how mammalian cells sense oxygen levels to coordinate diverse biological outputs during hypoxia. The best-studied mechanism of response to hypoxia involves hypoxia inducible factors (HIFs), which are stabilized by low oxygen availability and control the expression of a multitude of genes, including those involved in cell survival, angiogenesis, glycolysis and invasion/metastasis. Importantly, changes in oxygen can also be sensed via other stress pathways as well as changes in metabolite levels and the generation of reactive oxygen species by mitochondria. Collectively, this leads to cellular adaptations of protein synthesis, energy metabolism, mitochondrial respiration, lipid and carbon metabolism as well as nutrient acquisition. These mechanisms are integral inputs into fine-tuning the responses to hypoxic stress.
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Affiliation(s)
- Pearl Lee
- Abramson Family Cancer Research Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
| | - Navdeep S Chandel
- Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
- Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
| | - M Celeste Simon
- Abramson Family Cancer Research Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
- Department of Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
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70
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Jain IH, Calvo SE, Markhard AL, Skinner OS, To TL, Ast T, Mootha VK. Genetic Screen for Cell Fitness in High or Low Oxygen Highlights Mitochondrial and Lipid Metabolism. Cell 2020; 181:716-727.e11. [PMID: 32259488 PMCID: PMC7293541 DOI: 10.1016/j.cell.2020.03.029] [Citation(s) in RCA: 118] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 02/13/2020] [Accepted: 03/11/2020] [Indexed: 01/04/2023]
Abstract
Human cells are able to sense and adapt to variations in oxygen levels. Historically, much research in this field has focused on hypoxia-inducible factor (HIF) signaling and reactive oxygen species (ROS). Here, we perform genome-wide CRISPR growth screens at 21%, 5%, and 1% oxygen to systematically identify gene knockouts with relative fitness defects in high oxygen (213 genes) or low oxygen (109 genes), most without known connection to HIF or ROS. Knockouts of many mitochondrial pathways thought to be essential, including complex I and enzymes in Fe-S biosynthesis, grow relatively well at low oxygen and thus are buffered by hypoxia. In contrast, in certain cell types, knockout of lipid biosynthetic and peroxisomal genes causes fitness defects only in low oxygen. Our resource nominates genetic diseases whose severity may be modulated by oxygen and links hundreds of genes to oxygen homeostasis.
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Affiliation(s)
- Isha H Jain
- Howard Hughes Medical Institute, Department of Molecular Biology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA; Broad Institute, Cambridge, MA 02142, USA
| | - Sarah E Calvo
- Howard Hughes Medical Institute, Department of Molecular Biology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA; Broad Institute, Cambridge, MA 02142, USA
| | - Andrew L Markhard
- Howard Hughes Medical Institute, Department of Molecular Biology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA; Broad Institute, Cambridge, MA 02142, USA
| | - Owen S Skinner
- Howard Hughes Medical Institute, Department of Molecular Biology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA; Broad Institute, Cambridge, MA 02142, USA
| | - Tsz-Leung To
- Howard Hughes Medical Institute, Department of Molecular Biology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA; Broad Institute, Cambridge, MA 02142, USA
| | - Tslil Ast
- Howard Hughes Medical Institute, Department of Molecular Biology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA; Broad Institute, Cambridge, MA 02142, USA
| | - Vamsi K Mootha
- Howard Hughes Medical Institute, Department of Molecular Biology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA; Broad Institute, Cambridge, MA 02142, USA.
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71
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Yang L, Garcia Canaveras JC, Chen Z, Wang L, Liang L, Jang C, Mayr JA, Zhang Z, Ghergurovich JM, Zhan L, Joshi S, Hu Z, McReynolds MR, Su X, White E, Morscher RJ, Rabinowitz JD. Serine Catabolism Feeds NADH when Respiration Is Impaired. Cell Metab 2020; 31:809-821.e6. [PMID: 32187526 PMCID: PMC7397714 DOI: 10.1016/j.cmet.2020.02.017] [Citation(s) in RCA: 108] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 12/09/2019] [Accepted: 02/26/2020] [Indexed: 01/18/2023]
Abstract
NADH provides electrons for aerobic ATP production. In cells deprived of oxygen or with impaired electron transport chain activity, NADH accumulation can be toxic. To minimize such toxicity, elevated NADH inhibits the classical NADH-producing pathways: glucose, glutamine, and fat oxidation. Here, through deuterium-tracing studies in cultured cells and mice, we show that folate-dependent serine catabolism also produces substantial NADH. Strikingly, when respiration is impaired, serine catabolism through methylene tetrahydrofolate dehydrogenase (MTHFD2) becomes a major NADH source. In cells whose respiration is slowed by hypoxia, metformin, or genetic lesions, mitochondrial serine catabolism inhibition partially normalizes NADH levels and facilitates cell growth. In mice with engineered mitochondrial complex I deficiency (NDUSF4-/-), serine's contribution to NADH is elevated, and progression of spasticity is modestly slowed by pharmacological blockade of serine degradation. Thus, when respiration is impaired, serine catabolism contributes to toxic NADH accumulation.
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Affiliation(s)
- Lifeng Yang
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA; Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | - Juan Carlos Garcia Canaveras
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA; Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | - Zihong Chen
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA; Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | - Lin Wang
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA; Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | - Lingfan Liang
- School of Pharmaceutical Sciences, Tsinghua University, Beijing 100084, China
| | - Cholsoon Jang
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA; Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | - Johannes A Mayr
- Department of Pediatrics, Salzburger Landeskliniken and Paracelsus Medical University, Salzburg 5020, Austria
| | - Zhaoyue Zhang
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA; Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | - Jonathan M Ghergurovich
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA; Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Le Zhan
- Rutgers Cancer Institute of New Jersey, New Brunswick, NJ 08903, USA
| | - Shilpy Joshi
- Rutgers Cancer Institute of New Jersey, New Brunswick, NJ 08903, USA
| | - Zhixian Hu
- Rutgers Cancer Institute of New Jersey, New Brunswick, NJ 08903, USA
| | - Melanie R McReynolds
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA; Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | - Xiaoyang Su
- Rutgers Cancer Institute of New Jersey, New Brunswick, NJ 08903, USA; Department of Medicine, Robert Wood Johnson Medical School, Rutgers University, New Brunswick, NJ 08901, USA
| | - Eileen White
- Rutgers Cancer Institute of New Jersey, New Brunswick, NJ 08903, USA; Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, NJ 08854, USA
| | | | - Joshua D Rabinowitz
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA; Department of Chemistry, Princeton University, Princeton, NJ 08544, USA; Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA.
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72
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Abnormalities of hydrogen sulfide and glutathione pathways in mitochondrial dysfunction. J Adv Res 2020; 27:79-84. [PMID: 33318868 PMCID: PMC7728579 DOI: 10.1016/j.jare.2020.04.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 03/31/2020] [Accepted: 04/01/2020] [Indexed: 12/17/2022] Open
Abstract
Background Mitochondrial disorders are genetic diseases for which therapy remains woefully inadequate. Therapy of these disorders is particularly challenging partially due to the heterogeneity and tissue-specificity of pathomechanisms involved in these disorders. Abnormalities in hydrogen sulfide (H2S) metabolism are emerging as novel mechanism in mitochondrial dysfunction. However, further studies are necessary to understand the effects, protective or detrimental, of these abnormalities, and their relevance, in mitochondrial diseases. Aim of Review To review the recent evidences of derangement of the metabolism of H2S, at biosynthesis or oxidation levels, in mitochondrial dysfunction, focusing specifically on the alterations of H2S oxidation caused by primary Coenzyme Q (CoQ) deficiency. Key Scientific Concepts of Review Mitochondria play a key role in the regulation of H2S and GSH metabolism pathways. However, further studies are needed to understand the consequences of abnormalities of H2S and GSH synthesis on the oxidation pathway, and vice versa; and on the levels of H2S and GSH, their tissue-specific detrimental effects, and their role the role in mitochondrial diseases. Beside the known H2S pathways, additional, tissue-specific, enzymatic systems, involved in H2S production and elimination, might exist.
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73
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Mitochondrial Diseases: Hope for the Future. Cell 2020; 181:168-188. [PMID: 32220313 DOI: 10.1016/j.cell.2020.02.051] [Citation(s) in RCA: 226] [Impact Index Per Article: 56.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 02/21/2020] [Accepted: 02/24/2020] [Indexed: 01/15/2023]
Abstract
Mitochondrial diseases are clinically heterogeneous disorders caused by a wide spectrum of mutations in genes encoded by either the nuclear or the mitochondrial genome. Treatments for mitochondrial diseases are currently focused on symptomatic management rather than improving the biochemical defect caused by a particular mutation. This review focuses on the latest advances in the development of treatments for mitochondrial disease, both small molecules and gene therapies, as well as methods to prevent transmission of mitochondrial disease through the germline.
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Stepanova A, Galkin A. Measurement of mitochondrial H 2O 2 production under varying O 2 tensions. Methods Cell Biol 2020; 155:273-293. [PMID: 32183962 PMCID: PMC9897472 DOI: 10.1016/bs.mcb.2019.12.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Mitochondria-derived reactive oxygen species (ROS) play an important role in the development of several pathologies and are also involved in physiological signaling. Molecular oxygen is the direct substrate of complex IV of the respiratory chain, and at the same time, its partial reduction in mitochondria results in the formation of ROS, mainly H2O2. The accurate knowledge of the dependence of H2O2 production on oxygen concentration is vital for the studies of tissue ischemia/reperfusion, where the relationship between oxygen availability, respiration, and ROS production is critical. In this chapter, we describe a straightforward and reliable protocol for the assessment of H2O2 release by mitochondria at varying oxygen concentrations. This method can be used for any ROS-generating system where the effect of oxygen level on H2O2 production needs to be assessed.
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Abstract
Epilepsy is frequently a severe and sinister symptom in primary mitochondrial diseases, a group of more than 350 different genetic disorders characterized by mitochondrial dysfunction and extreme clinical and biochemical heterogeneity. Mitochondrial epilepsy is notoriously difficult to manage, principally because the vast majority of primary mitochondrial diseases currently lack effective therapies. Treating the underlying mitochondrial disorder is likely to be a more effective strategy than using traditional antiepileptic drugs. This review, initially presented at the 7th London-Innsbruck Colloquium on Status Epilepticus and Acute Seizures at the Francis Crick Institute in London, summarizes the currently available and emerging therapies for mitochondrial epilepsy. Potentially treatable mitochondrial diseases include disorders of coenzyme Q10 biosynthesis and a group of mitochondrial respiratory chain complex I subunit and assembly factor defects that respond to riboflavin (vitamin B2). Approaches that have been adopted in actively recruiting clinical trials include redox modulation, harnessing mitochondrial biogenesis, using rapamycin to target mitophagy, nucleoside supplementation, and gene and cell therapies. Most of the clinical trials are at an early stage (Phase 1 or 2) and none of the currently active trials is specifically targeting mitochondrial epilepsy. This article is part of the Special Issue "Proceedings of the 7th London-Innsbruck Colloquium on Status Epilepticus and Acute Seizures".
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Abstract
Dysfunctions of the mitochondrial electron transport chain cause severe, currently untreatable, diseases in humans. A new study by Jain et al. (2019) reports increased oxygen levels in the brain of complex-I-deficient mice. Reducing the O2 levels by hypoxia, carbon monoxide, or anemia, improved the clinical phenotype and prolonged the lifespan of the mouse model.
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Affiliation(s)
- Carlo Viscomi
- MRC-Mitochondrial Biology Unit, Cambridge CB2 0XY, UK
| | - Massimo Zeviani
- MRC-Mitochondrial Biology Unit, Cambridge CB2 0XY, UK; Department of Neurosciences, University of Padova, Padova, Italy.
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