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Shammas MK, Huang X, Wu BP, Fessler E, Song I, Randolph NP, Li Y, Bleck CK, Springer DA, Fratter C, Barbosa IA, Powers AF, Quirós PM, Lopez-Otin C, Jae LT, Poulton J, Narendra DP. OMA1 mediates local and global stress responses against protein misfolding in CHCHD10 mitochondrial myopathy. J Clin Invest 2022; 132:157504. [PMID: 35700042 PMCID: PMC9282932 DOI: 10.1172/jci157504] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 06/07/2022] [Indexed: 11/21/2022] Open
Abstract
Mitochondrial stress triggers a response in the cell’s mitochondria and nucleus, but how these stress responses are coordinated in vivo is poorly understood. Here, we characterize a family with myopathy caused by a dominant p.G58R mutation in the mitochondrial protein CHCHD10. To understand the disease etiology, we developed a knockin (KI) mouse model and found that mutant CHCHD10 aggregated in affected tissues, applying a toxic protein stress to the inner mitochondrial membrane. Unexpectedly, the survival of CHCHD10-KI mice depended on a protective stress response mediated by the mitochondrial metalloendopeptidase OMA1. The OMA1 stress response acted both locally within mitochondria, causing mitochondrial fragmentation, and signaled outside the mitochondria, activating the integrated stress response through cleavage of DAP3-binding cell death enhancer 1 (DELE1). We additionally identified an isoform switch in the terminal complex of the electron transport chain as a component of this response. Our results demonstrate that OMA1 was critical for neonatal survival conditionally in the setting of inner mitochondrial membrane stress, coordinating local and global stress responses to reshape the mitochondrial network and proteome.
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Affiliation(s)
- Mario K Shammas
- Inherited Movement Disorders Unit, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, Bethesda, United States of America
| | - Xiaoping Huang
- Inherited Movement Disorders Unit, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, Bethesda, United States of America
| | - Beverly P Wu
- Inherited Movement Disorders Unit, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, Bethesda, United States of America
| | - Evelyn Fessler
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Insung Song
- Inherited Movement Disorders Unit, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, Bethesda, United States of America
| | - Nicholas P Randolph
- Inherited Movement Disorders Unit, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, Bethesda, United States of America
| | - Yan Li
- Proteomics Core Facility, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, United States of America
| | - Christopher Ke Bleck
- Electron Microscopy Core Facility, National Heart, Lung, and Blood Institute, Bethesda, United States of America
| | - Danielle A Springer
- Mouse Phenotyping Core, National Heart, Lung, and Blood Institute, Bethesda, United States of America
| | - Carl Fratter
- Oxford Medical Genetics Laboratories, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
| | - Ines A Barbosa
- Department of Medical and Molecular Genetics, King's College London, London, United Kingdom
| | | | - Pedro M Quirós
- Departamento de Bioquímica y Biología Molecular, Universidad de Oviedo, Oviedo, Spain
| | - Carlos Lopez-Otin
- Departamento de Bioquímica y Biología Molecular, Universidad de Oviedo, Oviedo, Spain
| | - Lucas T Jae
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Joanna Poulton
- Nuffield Department of Women's and Reproductive Health, University of Oxford, Oxford, United Kingdom
| | - Derek P Narendra
- Inherited Movement Disorders Unit, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, Bethesda, United States of America
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2
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Wainwright L, Hargreaves IP, Georgian AR, Turner C, Dalton RN, Abbott NJ, Heales SJR, Preston JE. CoQ 10 Deficient Endothelial Cell Culture Model for the Investigation of CoQ 10 Blood-Brain Barrier Transport. J Clin Med 2020; 9:jcm9103236. [PMID: 33050406 PMCID: PMC7601674 DOI: 10.3390/jcm9103236] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 10/02/2020] [Accepted: 10/06/2020] [Indexed: 12/31/2022] Open
Abstract
Primary coenzyme Q10 (CoQ10) deficiency is unique among mitochondrial respiratory chain disorders in that it is potentially treatable if high-dose CoQ10 supplements are given in the early stages of the disease. While supplements improve peripheral abnormalities, neurological symptoms are only partially or temporarily ameliorated. The reasons for this refractory response to CoQ10 supplementation are unclear, however, a contributory factor may be the poor transfer of CoQ10 across the blood-brain barrier (BBB). The aim of this study was to investigate mechanisms of CoQ10 transport across the BBB, using normal and pathophysiological (CoQ10 deficient) cell culture models. The study identifies lipoprotein-associated CoQ10 transcytosis in both directions across the in vitro BBB. Uptake via SR-B1 (Scavenger Receptor) and RAGE (Receptor for Advanced Glycation Endproducts), is matched by efflux via LDLR (Low Density Lipoprotein Receptor) transporters, resulting in no "net" transport across the BBB. In the CoQ10 deficient model, BBB tight junctions were disrupted and CoQ10 "net" transport to the brain side increased. The addition of anti-oxidants did not improve CoQ10 uptake to the brain side. This study is the first to generate in vitro BBB endothelial cell models of CoQ10 deficiency, and the first to identify lipoprotein-associated uptake and efflux mechanisms regulating CoQ10 distribution across the BBB. The results imply that the uptake of exogenous CoQ10 into the brain might be improved by the administration of LDLR inhibitors, or by interventions to stimulate luminal activity of SR-B1 transporters.
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Affiliation(s)
- Luke Wainwright
- UCL Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK;
| | - Iain P. Hargreaves
- Neurometabolic Unit, National Hospital for Neurology and Neurosurgery, University College London Hospitals NHS Foundation Trust, London WC1N 3BG, UK;
- Department of Pharmacy and Biomolecular Science, Liverpool John Moores University, Liverpool L3 5UA, UK
| | - Ana R. Georgian
- School of Cancer and Pharmaceutical Sciences, King’s College London, London SE1 9NH, UK; (A.R.G.); (N.J.A.)
| | - Charles Turner
- Evelina London Children’s Hospital, Guy’s and St. Thomas’ NHS Foundation Trust, London SE1 7EH, UK; (C.T.); (R.N.D.)
| | - R. Neil Dalton
- Evelina London Children’s Hospital, Guy’s and St. Thomas’ NHS Foundation Trust, London SE1 7EH, UK; (C.T.); (R.N.D.)
| | - N. Joan Abbott
- School of Cancer and Pharmaceutical Sciences, King’s College London, London SE1 9NH, UK; (A.R.G.); (N.J.A.)
| | - Simon J. R. Heales
- Neurometabolic Unit, National Hospital for Neurology and Neurosurgery, University College London Hospitals NHS Foundation Trust, London WC1N 3BG, UK;
- UCL Great Ormond Street Institute of Child Health, University College London, London WC1E 6BT, UK;
| | - Jane E. Preston
- School of Cancer and Pharmaceutical Sciences, King’s College London, London SE1 9NH, UK; (A.R.G.); (N.J.A.)
- Correspondence: ; Tel.: +44-207-848-4881
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3
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Ghosh R, Wood-Kaczmar A, Dobson L, Smith EJ, Sirinathsinghji EC, Kriston-Vizi J, Hargreaves IP, Heaton R, Herrmann F, Abramov AY, Lam AJ, Heales SJ, Ketteler R, Bates GP, Andre R, Tabrizi SJ. Expression of mutant exon 1 huntingtin fragments in human neural stem cells and neurons causes inclusion formation and mitochondrial dysfunction. FASEB J 2020; 34:8139-8154. [PMID: 32329133 PMCID: PMC8432155 DOI: 10.1096/fj.201902277rr] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Revised: 03/27/2020] [Accepted: 04/02/2020] [Indexed: 11/11/2022]
Abstract
Robust cellular models are key in determining pathological mechanisms that lead to neurotoxicity in Huntington's disease (HD) and for high throughput pre‐clinical screening of potential therapeutic compounds. Such models exist but mostly comprise non‐human or non‐neuronal cells that may not recapitulate the correct biochemical milieu involved in pathology. We have developed a new human neuronal cell model of HD, using neural stem cells (ReNcell VM NSCs) stably transduced to express exon 1 huntingtin (HTT) fragments with variable length polyglutamine (polyQ) tracts. Using a system with matched expression levels of exon 1 HTT fragments, we investigated the effect of increasing polyQ repeat length on HTT inclusion formation, location, neuronal survival, and mitochondrial function with a view to creating an in vitro screening platform for therapeutic screening. We found that expression of exon 1 HTT fragments with longer polyQ tracts led to the formation of intra‐nuclear inclusions in a polyQ length‐dependent manner during neurogenesis. There was no overt effect on neuronal viability, but defects of mitochondrial function were found in the pathogenic lines. Thus, we have a human neuronal cell model of HD that may recapitulate some of the earliest stages of HD pathogenesis, namely inclusion formation and mitochondrial dysfunction.
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Affiliation(s)
- Rhia Ghosh
- Huntington's Disease Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Alison Wood-Kaczmar
- Huntington's Disease Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Lucianne Dobson
- Huntington's Disease Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Edward J Smith
- Huntington's Disease Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Eva C Sirinathsinghji
- Huntington's Disease Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Janos Kriston-Vizi
- MRC Laboratory for Molecular Cell Biology, University College London, London, UK
| | | | - Robert Heaton
- School of Pharmacy, Liverpool John Moores University, Liverpool, UK
| | | | - Andrey Y Abramov
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Amanda J Lam
- Neurometabolic Unit, National Hospital for Neurology and Neurosurgery, London, UK
| | - Simon J Heales
- Neurometabolic Unit, National Hospital for Neurology and Neurosurgery, London, UK
| | - Robin Ketteler
- MRC Laboratory for Molecular Cell Biology, University College London, London, UK
| | - Gillian P Bates
- Huntington's Disease Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Ralph Andre
- Huntington's Disease Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Sarah J Tabrizi
- Huntington's Disease Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, University College London, London, UK
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4
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Coenzyme Q 10 Assessment and the Establishment of a Neuronal Cell Model of CoQ 10 Deficiency. Methods Mol Biol 2020. [PMID: 32219756 DOI: 10.1007/978-1-0716-0471-7_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Coenzyme Q10 (CoQ10) plays a key role as an electron carrier in the mitochondrial respiratory chain and as a cellular antioxidant molecule. A deficit in CoQ10 status may contribute to disease pathophysiology by causing a failure mitochondrial energy metabolism as well as compromising cellular antioxidant capacity. This chapter outlines the analytical methods used for determining cellular CoQ10 status using high-pressure liquid chromatography with ultraviolet (HPLC-UV) detection. In addition, we present a pharmacological procedure for establishing a human neuronal cell model of CoQ10 deficiency, for use in research studies.
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5
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Coats CJ, Heywood WE, Virasami A, Ashrafi N, Syrris P, Dos Remedios C, Treibel TA, Moon JC, Lopes LR, McGregor CGA, Ashworth M, Sebire NJ, McKenna WJ, Mills K, Elliott PM. Proteomic Analysis of the Myocardium in Hypertrophic Obstructive Cardiomyopathy. CIRCULATION-GENOMIC AND PRECISION MEDICINE 2019; 11:e001974. [PMID: 30562113 DOI: 10.1161/circgen.117.001974] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Hypertrophic cardiomyopathy (HCM) is characterized by a complex phenotype that is only partly explained by the biological effects of individual genetic variants. The aim of this study was to use proteomic analysis of myocardial tissue to explore the postgenomic phenotype. METHODS Label-free proteomic analysis was used initially to compare protein profiles in myocardial samples from 11 patients with HCM undergoing surgical myectomy with control samples from 6 healthy unused donor hearts. Differentially expressed proteins of interest were validated in myocardial samples from 65 unrelated individuals (HCM [n=51], controls [n=7], and aortic stenosis [n=7]) by the development and use of targeted multiple reaction monitoring-based triple quadrupole mass spectrometry. RESULTS In this exploratory study, 1586 proteins were identified with 151 proteins differentially expressed in HCM samples compared with controls ( P<0.05). Protein expression profiling showed that many proteins identified in the initial discovery study were associated with metabolism, muscle contraction, calcium regulation, and oxidative stress. Proteins downregulated in HCM versus controls included creatine kinase M-type, fructose-bisphosphate aldolase A, and phosphoglycerate mutase ( P<0.001). Proteins upregulated in HCM included lumican, carbonic anhydrase 3, desmin, α-actin skeletal, and FHL1 (four and a half LIM domain protein 1; P<0.01). Myocardial lumican concentration correlated with the left atrial area (ρ=0.34, P=0.015), late gadolinium enhancement on cardiac magnetic resonance imaging ( P=0.03) and the presence of a pathogenic sarcomere mutation ( P=0.04). CONCLUSIONS The myocardial proteome of HCM provides supporting evidence for dysregulation of metabolic and structural proteins. The finding that lumican is raised in HCM hearts provides insight into the myocardial fibrosis that characterizes this disease.
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Affiliation(s)
- Caroline J Coats
- University College London Institute of Cardiovascular Science, London, United Kingdom (C.J.C., P.S., T.A.T., J.C.M., L.R.L., C.G.A.M., W.J.M., P.M.E.).,University College London Great Ormond Street Institute of Child Health, London, United Kingdom (C.J.C., W.E.H., N.A., K.M.)
| | - Wendy E Heywood
- University College London Great Ormond Street Institute of Child Health, London, United Kingdom (C.J.C., W.E.H., N.A., K.M.)
| | - Alex Virasami
- Histopathology Unit, Great Ormond Street Hospital for Children, London, United Kingdom (A.V., M.A., N.J.S.)
| | - Nadia Ashrafi
- University College London Great Ormond Street Institute of Child Health, London, United Kingdom (C.J.C., W.E.H., N.A., K.M.)
| | - Petros Syrris
- University College London Institute of Cardiovascular Science, London, United Kingdom (C.J.C., P.S., T.A.T., J.C.M., L.R.L., C.G.A.M., W.J.M., P.M.E.)
| | - Cris Dos Remedios
- Department of Anatomy and Histology, Bosch Institute, The University of Sydney, New South Wales, Australia (C.d.R.)
| | - Thomas A Treibel
- University College London Institute of Cardiovascular Science, London, United Kingdom (C.J.C., P.S., T.A.T., J.C.M., L.R.L., C.G.A.M., W.J.M., P.M.E.).,Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom (T.A.T., J.C.M., L.R.L., P.M.E.)
| | - James C Moon
- University College London Institute of Cardiovascular Science, London, United Kingdom (C.J.C., P.S., T.A.T., J.C.M., L.R.L., C.G.A.M., W.J.M., P.M.E.).,Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom (T.A.T., J.C.M., L.R.L., P.M.E.)
| | - Luis R Lopes
- University College London Institute of Cardiovascular Science, London, United Kingdom (C.J.C., P.S., T.A.T., J.C.M., L.R.L., C.G.A.M., W.J.M., P.M.E.).,Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom (T.A.T., J.C.M., L.R.L., P.M.E.)
| | - Christopher G A McGregor
- University College London Institute of Cardiovascular Science, London, United Kingdom (C.J.C., P.S., T.A.T., J.C.M., L.R.L., C.G.A.M., W.J.M., P.M.E.)
| | - Michael Ashworth
- Histopathology Unit, Great Ormond Street Hospital for Children, London, United Kingdom (A.V., M.A., N.J.S.)
| | - Neil J Sebire
- Histopathology Unit, Great Ormond Street Hospital for Children, London, United Kingdom (A.V., M.A., N.J.S.)
| | - William J McKenna
- University College London Institute of Cardiovascular Science, London, United Kingdom (C.J.C., P.S., T.A.T., J.C.M., L.R.L., C.G.A.M., W.J.M., P.M.E.)
| | - Kevin Mills
- University College London Great Ormond Street Institute of Child Health, London, United Kingdom (C.J.C., W.E.H., N.A., K.M.)
| | - Perry M Elliott
- University College London Institute of Cardiovascular Science, London, United Kingdom (C.J.C., P.S., T.A.T., J.C.M., L.R.L., C.G.A.M., W.J.M., P.M.E.).,Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom (T.A.T., J.C.M., L.R.L., P.M.E.)
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6
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Coats CJ, Heywood WE, Virasami A, Ashrafi N, Syrris P, dos Remedios C, Treibel TA, Moon JC, Lopes LR, McGregor CG, Ashworth M, Sebire NJ, McKenna WJ, Mills K, Elliott PM. Proteomic Analysis of the Myocardium in Hypertrophic Obstructive Cardiomyopathy. CIRCULATION-GENOMIC AND PRECISION MEDICINE 2018. [DOI: 10.1161/circgenetics.117.001974] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Caroline J. Coats
- University College London Institute of Cardiovascular Science, London, United Kingdom (C.J.C., P.S., T.A.T., J.C.M., L.R.L., C.G.A.M., W.J.M., P.M.E.)
- University College London Great Ormond Street Institute of Child Health, London, United Kingdom (C.J.C., W.E.H., N.A., K.M.)
| | - Wendy E. Heywood
- University College London Great Ormond Street Institute of Child Health, London, United Kingdom (C.J.C., W.E.H., N.A., K.M.)
| | - Alex Virasami
- Histopathology Unit, Great Ormond Street Hospital for Children, London, United Kingdom (A.V., M.A., N.J.S.)
| | - Nadia Ashrafi
- University College London Great Ormond Street Institute of Child Health, London, United Kingdom (C.J.C., W.E.H., N.A., K.M.)
| | - Petros Syrris
- University College London Institute of Cardiovascular Science, London, United Kingdom (C.J.C., P.S., T.A.T., J.C.M., L.R.L., C.G.A.M., W.J.M., P.M.E.)
| | - Cris dos Remedios
- Department of Anatomy and Histology, Bosch Institute, The University of Sydney, New South Wales, Australia (C.d.R.)
| | - Thomas A. Treibel
- University College London Institute of Cardiovascular Science, London, United Kingdom (C.J.C., P.S., T.A.T., J.C.M., L.R.L., C.G.A.M., W.J.M., P.M.E.)
- Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom (T.A.T., J.C.M., L.R.L., P.M.E.)
| | - James C. Moon
- University College London Institute of Cardiovascular Science, London, United Kingdom (C.J.C., P.S., T.A.T., J.C.M., L.R.L., C.G.A.M., W.J.M., P.M.E.)
- Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom (T.A.T., J.C.M., L.R.L., P.M.E.)
| | - Luis R. Lopes
- University College London Institute of Cardiovascular Science, London, United Kingdom (C.J.C., P.S., T.A.T., J.C.M., L.R.L., C.G.A.M., W.J.M., P.M.E.)
- Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom (T.A.T., J.C.M., L.R.L., P.M.E.)
| | - Christopher G.A. McGregor
- University College London Institute of Cardiovascular Science, London, United Kingdom (C.J.C., P.S., T.A.T., J.C.M., L.R.L., C.G.A.M., W.J.M., P.M.E.)
| | - Michael Ashworth
- Histopathology Unit, Great Ormond Street Hospital for Children, London, United Kingdom (A.V., M.A., N.J.S.)
| | - Neil J. Sebire
- Histopathology Unit, Great Ormond Street Hospital for Children, London, United Kingdom (A.V., M.A., N.J.S.)
| | - William J. McKenna
- University College London Institute of Cardiovascular Science, London, United Kingdom (C.J.C., P.S., T.A.T., J.C.M., L.R.L., C.G.A.M., W.J.M., P.M.E.)
| | - Kevin Mills
- University College London Great Ormond Street Institute of Child Health, London, United Kingdom (C.J.C., W.E.H., N.A., K.M.)
| | - Perry M. Elliott
- University College London Institute of Cardiovascular Science, London, United Kingdom (C.J.C., P.S., T.A.T., J.C.M., L.R.L., C.G.A.M., W.J.M., P.M.E.)
- Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom (T.A.T., J.C.M., L.R.L., P.M.E.)
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7
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Lear PV, González-Touceda D, Porteiro Couto B, Viaño P, Guymer V, Remzova E, Tunn R, Chalasani A, García-Caballero T, Hargreaves IP, Tynan PW, Christian HC, Nogueiras R, Parrington J, Diéguez C. Absence of intracellular ion channels TPC1 and TPC2 leads to mature-onset obesity in male mice, due to impaired lipid availability for thermogenesis in brown adipose tissue. Endocrinology 2015; 156:975-86. [PMID: 25545384 PMCID: PMC4330317 DOI: 10.1210/en.2014-1766] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Accepted: 12/23/2014] [Indexed: 12/11/2022]
Abstract
Intracellular calcium-permeable channels have been implicated in thermogenic function of murine brown and brite/beige adipocytes, respectively transient receptor potential melastin-8 and transient receptor potential vanilloid-4. Because the endo-lysosomal two-pore channels (TPCs) have also been ascribed with metabolic functionality, we studied the effect of simultaneously knocking out TPC1 and TPC2 on body composition and energy balance in male mice fed a chow diet. Compared with wild-type mice, TPC1 and TPC2 double knockout (Tpcn1/2(-/-)) animals had a higher respiratory quotient and became obese between 6 and 9 months of age. Although food intake was unaltered, interscapular brown adipose tissue (BAT) maximal temperature and lean-mass adjusted oxygen consumption were lower in Tpcn1/2(-/-) than in wild type mice. Phosphorylated hormone-sensitive lipase expression, lipid density and expression of β-adrenergic receptors were also lower in Tpcn1/2(-/-) BAT, whereas mitochondrial respiratory chain function and uncoupling protein-1 expression remained intact. We conclude that Tpcn1/2(-/-) mice show mature-onset obesity due to reduced lipid availability and use, and a defect in β-adrenergic receptor signaling, leading to impaired thermogenic activity, in BAT.
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Affiliation(s)
- Pamela V. Lear
- Department of Physiology (P.V.L., D.G.-T., B.P.C., R.N., C.D.), Centre for Research in Molecular Medicine and Chronic Diseases, University of Santiago de Compostela and Institute of Health Sciences, and Department of Morphological Sciences (P.V., T.G.-C.), School of Medicine and University Clinical Hospital, University of Santiago de Compostela, Santiago de Compostela 15782, Spain; Department of Pharmacology (P.V.L., R.T., P.W.T., J.P.), Oxford University, Oxford OX1 3QT, United Kingdom; Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición (D.G.-T., B.P.C., R.N., C.D.), 15706, Santiago de Compostela, Spain; Department of Physiology, Anatomy, and Genetics (V.G., H.C.C.), Oxford University, Oxford OX1 3QX, United Kingdom; and Neurometabolic Unit (E.R., A.C., I.P.H.), National Hospital for Neurology and Neurosurgery, University College London Hospitals, Queen Square, London WC1N 3BG, United Kingdom
| | | | | | - Patricia Viaño
- Department of Physiology (P.V.L., D.G.-T., B.P.C., R.N., C.D.), Centre for Research in Molecular Medicine and Chronic Diseases, University of Santiago de Compostela and Institute of Health Sciences, and Department of Morphological Sciences (P.V., T.G.-C.), School of Medicine and University Clinical Hospital, University of Santiago de Compostela, Santiago de Compostela 15782, Spain; Department of Pharmacology (P.V.L., R.T., P.W.T., J.P.), Oxford University, Oxford OX1 3QT, United Kingdom; Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición (D.G.-T., B.P.C., R.N., C.D.), 15706, Santiago de Compostela, Spain; Department of Physiology, Anatomy, and Genetics (V.G., H.C.C.), Oxford University, Oxford OX1 3QX, United Kingdom; and Neurometabolic Unit (E.R., A.C., I.P.H.), National Hospital for Neurology and Neurosurgery, University College London Hospitals, Queen Square, London WC1N 3BG, United Kingdom
| | - Vanessa Guymer
- Department of Physiology (P.V.L., D.G.-T., B.P.C., R.N., C.D.), Centre for Research in Molecular Medicine and Chronic Diseases, University of Santiago de Compostela and Institute of Health Sciences, and Department of Morphological Sciences (P.V., T.G.-C.), School of Medicine and University Clinical Hospital, University of Santiago de Compostela, Santiago de Compostela 15782, Spain; Department of Pharmacology (P.V.L., R.T., P.W.T., J.P.), Oxford University, Oxford OX1 3QT, United Kingdom; Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición (D.G.-T., B.P.C., R.N., C.D.), 15706, Santiago de Compostela, Spain; Department of Physiology, Anatomy, and Genetics (V.G., H.C.C.), Oxford University, Oxford OX1 3QX, United Kingdom; and Neurometabolic Unit (E.R., A.C., I.P.H.), National Hospital for Neurology and Neurosurgery, University College London Hospitals, Queen Square, London WC1N 3BG, United Kingdom
| | - Elena Remzova
- Department of Physiology (P.V.L., D.G.-T., B.P.C., R.N., C.D.), Centre for Research in Molecular Medicine and Chronic Diseases, University of Santiago de Compostela and Institute of Health Sciences, and Department of Morphological Sciences (P.V., T.G.-C.), School of Medicine and University Clinical Hospital, University of Santiago de Compostela, Santiago de Compostela 15782, Spain; Department of Pharmacology (P.V.L., R.T., P.W.T., J.P.), Oxford University, Oxford OX1 3QT, United Kingdom; Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición (D.G.-T., B.P.C., R.N., C.D.), 15706, Santiago de Compostela, Spain; Department of Physiology, Anatomy, and Genetics (V.G., H.C.C.), Oxford University, Oxford OX1 3QX, United Kingdom; and Neurometabolic Unit (E.R., A.C., I.P.H.), National Hospital for Neurology and Neurosurgery, University College London Hospitals, Queen Square, London WC1N 3BG, United Kingdom
| | - Ruth Tunn
- Department of Physiology (P.V.L., D.G.-T., B.P.C., R.N., C.D.), Centre for Research in Molecular Medicine and Chronic Diseases, University of Santiago de Compostela and Institute of Health Sciences, and Department of Morphological Sciences (P.V., T.G.-C.), School of Medicine and University Clinical Hospital, University of Santiago de Compostela, Santiago de Compostela 15782, Spain; Department of Pharmacology (P.V.L., R.T., P.W.T., J.P.), Oxford University, Oxford OX1 3QT, United Kingdom; Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición (D.G.-T., B.P.C., R.N., C.D.), 15706, Santiago de Compostela, Spain; Department of Physiology, Anatomy, and Genetics (V.G., H.C.C.), Oxford University, Oxford OX1 3QX, United Kingdom; and Neurometabolic Unit (E.R., A.C., I.P.H.), National Hospital for Neurology and Neurosurgery, University College London Hospitals, Queen Square, London WC1N 3BG, United Kingdom
| | - Annapurna Chalasani
- Department of Physiology (P.V.L., D.G.-T., B.P.C., R.N., C.D.), Centre for Research in Molecular Medicine and Chronic Diseases, University of Santiago de Compostela and Institute of Health Sciences, and Department of Morphological Sciences (P.V., T.G.-C.), School of Medicine and University Clinical Hospital, University of Santiago de Compostela, Santiago de Compostela 15782, Spain; Department of Pharmacology (P.V.L., R.T., P.W.T., J.P.), Oxford University, Oxford OX1 3QT, United Kingdom; Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición (D.G.-T., B.P.C., R.N., C.D.), 15706, Santiago de Compostela, Spain; Department of Physiology, Anatomy, and Genetics (V.G., H.C.C.), Oxford University, Oxford OX1 3QX, United Kingdom; and Neurometabolic Unit (E.R., A.C., I.P.H.), National Hospital for Neurology and Neurosurgery, University College London Hospitals, Queen Square, London WC1N 3BG, United Kingdom
| | - Tomás García-Caballero
- Department of Physiology (P.V.L., D.G.-T., B.P.C., R.N., C.D.), Centre for Research in Molecular Medicine and Chronic Diseases, University of Santiago de Compostela and Institute of Health Sciences, and Department of Morphological Sciences (P.V., T.G.-C.), School of Medicine and University Clinical Hospital, University of Santiago de Compostela, Santiago de Compostela 15782, Spain; Department of Pharmacology (P.V.L., R.T., P.W.T., J.P.), Oxford University, Oxford OX1 3QT, United Kingdom; Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición (D.G.-T., B.P.C., R.N., C.D.), 15706, Santiago de Compostela, Spain; Department of Physiology, Anatomy, and Genetics (V.G., H.C.C.), Oxford University, Oxford OX1 3QX, United Kingdom; and Neurometabolic Unit (E.R., A.C., I.P.H.), National Hospital for Neurology and Neurosurgery, University College London Hospitals, Queen Square, London WC1N 3BG, United Kingdom
| | - Iain P. Hargreaves
- Department of Physiology (P.V.L., D.G.-T., B.P.C., R.N., C.D.), Centre for Research in Molecular Medicine and Chronic Diseases, University of Santiago de Compostela and Institute of Health Sciences, and Department of Morphological Sciences (P.V., T.G.-C.), School of Medicine and University Clinical Hospital, University of Santiago de Compostela, Santiago de Compostela 15782, Spain; Department of Pharmacology (P.V.L., R.T., P.W.T., J.P.), Oxford University, Oxford OX1 3QT, United Kingdom; Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición (D.G.-T., B.P.C., R.N., C.D.), 15706, Santiago de Compostela, Spain; Department of Physiology, Anatomy, and Genetics (V.G., H.C.C.), Oxford University, Oxford OX1 3QX, United Kingdom; and Neurometabolic Unit (E.R., A.C., I.P.H.), National Hospital for Neurology and Neurosurgery, University College London Hospitals, Queen Square, London WC1N 3BG, United Kingdom
| | - Patricia W. Tynan
- Department of Physiology (P.V.L., D.G.-T., B.P.C., R.N., C.D.), Centre for Research in Molecular Medicine and Chronic Diseases, University of Santiago de Compostela and Institute of Health Sciences, and Department of Morphological Sciences (P.V., T.G.-C.), School of Medicine and University Clinical Hospital, University of Santiago de Compostela, Santiago de Compostela 15782, Spain; Department of Pharmacology (P.V.L., R.T., P.W.T., J.P.), Oxford University, Oxford OX1 3QT, United Kingdom; Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición (D.G.-T., B.P.C., R.N., C.D.), 15706, Santiago de Compostela, Spain; Department of Physiology, Anatomy, and Genetics (V.G., H.C.C.), Oxford University, Oxford OX1 3QX, United Kingdom; and Neurometabolic Unit (E.R., A.C., I.P.H.), National Hospital for Neurology and Neurosurgery, University College London Hospitals, Queen Square, London WC1N 3BG, United Kingdom
| | - Helen C. Christian
- Department of Physiology (P.V.L., D.G.-T., B.P.C., R.N., C.D.), Centre for Research in Molecular Medicine and Chronic Diseases, University of Santiago de Compostela and Institute of Health Sciences, and Department of Morphological Sciences (P.V., T.G.-C.), School of Medicine and University Clinical Hospital, University of Santiago de Compostela, Santiago de Compostela 15782, Spain; Department of Pharmacology (P.V.L., R.T., P.W.T., J.P.), Oxford University, Oxford OX1 3QT, United Kingdom; Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición (D.G.-T., B.P.C., R.N., C.D.), 15706, Santiago de Compostela, Spain; Department of Physiology, Anatomy, and Genetics (V.G., H.C.C.), Oxford University, Oxford OX1 3QX, United Kingdom; and Neurometabolic Unit (E.R., A.C., I.P.H.), National Hospital for Neurology and Neurosurgery, University College London Hospitals, Queen Square, London WC1N 3BG, United Kingdom
| | - Rubén Nogueiras
- Department of Physiology (P.V.L., D.G.-T., B.P.C., R.N., C.D.), Centre for Research in Molecular Medicine and Chronic Diseases, University of Santiago de Compostela and Institute of Health Sciences, and Department of Morphological Sciences (P.V., T.G.-C.), School of Medicine and University Clinical Hospital, University of Santiago de Compostela, Santiago de Compostela 15782, Spain; Department of Pharmacology (P.V.L., R.T., P.W.T., J.P.), Oxford University, Oxford OX1 3QT, United Kingdom; Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición (D.G.-T., B.P.C., R.N., C.D.), 15706, Santiago de Compostela, Spain; Department of Physiology, Anatomy, and Genetics (V.G., H.C.C.), Oxford University, Oxford OX1 3QX, United Kingdom; and Neurometabolic Unit (E.R., A.C., I.P.H.), National Hospital for Neurology and Neurosurgery, University College London Hospitals, Queen Square, London WC1N 3BG, United Kingdom
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8
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Baruteau J, Hargreaves I, Krywawych S, Chalasani A, Land JM, Davison JE, Kwok MK, Christov G, Karimova A, Ashworth M, Anderson G, Prunty H, Rahman S, Grünewald S. Successful reversal of propionic acidaemia associated cardiomyopathy: evidence for low myocardial coenzyme Q10 status and secondary mitochondrial dysfunction as an underlying pathophysiological mechanism. Mitochondrion 2014; 17:150-6. [PMID: 25010387 DOI: 10.1016/j.mito.2014.07.001] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Revised: 05/07/2014] [Accepted: 07/01/2014] [Indexed: 12/30/2022]
Abstract
Dilated cardiomyopathy is a rare complication in propionic acidaemia (PA). Underlying pathophysiological mechanisms are poorly understood. We present a child of Pakistani consanguineous parents, diagnosed with late-onset PA at 18months of age. He presented a mild phenotype, showed no severe further decompensations, normal growth and psychomotor development on a low protein diet and carnitine supplementation. At 15years, a mildly dilated left ventricle was noticed. At 17years he presented after a 2-3month history of lethargy and weight loss with severe decompensated dilated cardiomyopathy. He was stabilised on inotropic support and continuous haemofiltration; a Berlin Heart biventricular assist device was implanted. He received d,l-hydroxybutyrate 200mg/kg/day, riboflavin and thiamine 200mg/day each and coenzyme Q10 (CoQ10). Myocardial biopsy showed endocardial fibrosis, enlarged mitochondria, with atypical cristae and slightly low respiratory chain (RC) complex IV activity relative to citrate synthase (0.012, reference range 0.014-0.034). Myocardial CoQ10 was markedly decreased (224pmol/mg, reference range 942-2738), with a marginally decreased white blood cell level (34pmol/mg reference range 37-133). The dose of CoQ10 was increased from 1.5 to 25mg/kg/day. Cardiomyopathy slowly improved allowing removal of the external mechanical cardiac support after 67days. We demonstrate for the first time low myocardial CoQ10 in cardiomyopathy in PA, highlighting secondary mitochondrial impairment as a relevant causative mechanism. According to these findings, a high-dose CoQ10 supplementation could be a potential adjuvant therapeutic to be considered in PA-related cardiomyopathy.
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Affiliation(s)
- J Baruteau
- Metabolic Medicine Department, Great Ormond Street Hospital, London, UK.
| | - I Hargreaves
- Neurometabolic Laboratory, National Hospital for Neurology and Neurosurgery, London, UK
| | - S Krywawych
- Chemical Pathology, Great Ormond Street Hospital, London, UK
| | - A Chalasani
- Neurometabolic Laboratory, National Hospital for Neurology and Neurosurgery, London, UK
| | - J M Land
- Neurometabolic Laboratory, National Hospital for Neurology and Neurosurgery, London, UK
| | - J E Davison
- Metabolic Medicine Department, Great Ormond Street Hospital, London, UK
| | - M K Kwok
- Metabolic Medicine Department, Great Ormond Street Hospital, London, UK
| | - G Christov
- Cardiothoracic Unit, Great Ormond Street Hospital, London, UK
| | - A Karimova
- Cardiothoracic Unit, Great Ormond Street Hospital, London, UK
| | - M Ashworth
- Pathology Laboratory, Great Ormond Street Hospital, London, UK
| | - G Anderson
- Pathology Laboratory, Great Ormond Street Hospital, London, UK
| | - H Prunty
- Chemical Pathology, Great Ormond Street Hospital, London, UK
| | - S Rahman
- Metabolic Medicine Department, Great Ormond Street Hospital, London, UK; Clinical and Molecular Genetics Unit, UCL Institute of Child Health, London, UK
| | - S Grünewald
- Metabolic Medicine Department, Great Ormond Street Hospital, London, UK; Clinical and Molecular Genetics Unit, UCL Institute of Child Health, London, UK
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9
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Liu YT, Hersheson J, Plagnol V, Fawcett K, Duberley KEC, Preza E, Hargreaves IP, Chalasani A, Laurá M, Wood NW, Reilly MM, Houlden H. Autosomal-recessive cerebellar ataxia caused by a novel ADCK3 mutation that elongates the protein: clinical, genetic and biochemical characterisation. J Neurol Neurosurg Psychiatry 2014; 85:493-8. [PMID: 24218524 PMCID: PMC3995328 DOI: 10.1136/jnnp-2013-306483] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Revised: 10/07/2013] [Accepted: 10/14/2013] [Indexed: 12/03/2022]
Abstract
BACKGROUND The autosomal-recessive cerebellar ataxias (ARCA) are a clinically and genetically heterogeneous group of neurodegenerative disorders. The large number of ARCA genes leads to delay and difficulties obtaining an exact diagnosis in many patients and families. Ubiquinone (CoQ10) deficiency is one of the potentially treatable causes of ARCAs as some patients respond to CoQ10 supplementation. The AarF domain containing kinase 3 gene (ADCK3) is one of several genes associated with CoQ10 deficiency. ADCK3 encodes a mitochondrial protein which functions as an electron-transfer membrane protein complex in the mitochondrial respiratory chain (MRC). METHODS We report two siblings from a consanguineous Pakistani family who presented with cerebellar ataxia and severe myoclonus from adolescence. Whole exome sequencing and biochemical assessment of fibroblasts were performed in the index patient. RESULTS A novel homozygous frameshift mutation in ADCK3 (p.Ser616Leufs*114), was identified in both siblings. This frameshift mutation results in the loss of the stop codon, extending the coding protein by 81 amino acids. Significant CoQ10 deficiency and reduced MRC enzyme activities in the index patient's fibroblasts suggested that the mutant protein may reduce the efficiency of mitochondrial electron transfer. CoQ10 supplementation was initiated following these genetic and biochemical analyses. She gained substantial improvement in myoclonic movements, ataxic gait and dysarthric speech after treatment. CONCLUSION This study highlights the importance of diagnosing ADCK3 mutations and the potential benefit of treatment for patients. The identification of this new mutation broadens the phenotypic spectrum associated with ADCK3 mutations and provides further understanding of their pathogenic mechanism.
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Affiliation(s)
- Yo-Tsen Liu
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK
- Department of Molecular Neuroscience, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK
- Section of Epilepsy, Department of Neurology, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan
- National Yang-Ming University School of Medicine, Taipei, Taiwan
| | - Joshua Hersheson
- Department of Molecular Neuroscience, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK
| | | | - Katherine Fawcett
- Department of Molecular Neuroscience, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK
| | - Kate E C Duberley
- Department of Molecular Neuroscience, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK
| | - Elisavet Preza
- Department of Molecular Neuroscience, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK
| | - Iain P Hargreaves
- Neurometabolic Unit, National Hospital of Neurology and Neurosurgery, London, UK
| | - Annapurna Chalasani
- Neurometabolic Unit, National Hospital of Neurology and Neurosurgery, London, UK
| | - Matilde Laurá
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK
- Department of Molecular Neuroscience, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK
| | - Nick W Wood
- Department of Molecular Neuroscience, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK
| | - Mary M Reilly
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK
- Department of Molecular Neuroscience, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK
| | - Henry Houlden
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK
- Department of Molecular Neuroscience, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK
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10
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Holmström KM, Baird L, Zhang Y, Hargreaves I, Chalasani A, Land JM, Stanyer L, Yamamoto M, Dinkova-Kostova AT, Abramov AY. Nrf2 impacts cellular bioenergetics by controlling substrate availability for mitochondrial respiration. Biol Open 2013; 2:761-70. [PMID: 23951401 PMCID: PMC3744067 DOI: 10.1242/bio.20134853] [Citation(s) in RCA: 322] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Accepted: 05/30/2013] [Indexed: 12/19/2022] Open
Abstract
Transcription factor Nrf2 and its repressor Keap1 regulate a network of cytoprotective genes involving more than 1% of the genome, their best known targets being drug-metabolizing and antioxidant genes. Here we demonstrate a novel role for this pathway in directly regulating mitochondrial bioenergetics in murine neurons and embryonic fibroblasts. Loss of Nrf2 leads to mitochondrial depolarisation, decreased ATP levels and impaired respiration, whereas genetic activation of Nrf2 increases the mitochondrial membrane potential and ATP levels, the rate of respiration and the efficiency of oxidative phosphorylation. We further show that Nrf2-deficient cells have increased production of ATP in glycolysis, which is then used by the F1Fo-ATPase for maintenance of the mitochondrial membrane potential. While the levels and in vitro activities of the respiratory complexes are unaffected by Nrf2 deletion, their activities in isolated mitochondria and intact live cells are substantially impaired. In addition, the rate of regeneration of NADH after inhibition of respiration is much slower in Nrf2-knockout cells than in their wild-type counterparts. Taken together, these results show that Nrf2 directly regulates cellular energy metabolism through modulating the availability of substrates for mitochondrial respiration. Our findings highlight the importance of efficient energy metabolism in Nrf2-mediated cytoprotection.
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Affiliation(s)
- Kira M. Holmström
- Department of Molecular Neuroscience, UCL Institute of Neurology, London WC1N 3BG, UK
| | - Liam Baird
- Jacqui Wood Cancer Centre, Division of Cancer Research, Medical Research Institute, University of Dundee, Dundee DD1 9SY, UK
| | - Ying Zhang
- Jacqui Wood Cancer Centre, Division of Cancer Research, Medical Research Institute, University of Dundee, Dundee DD1 9SY, UK
| | - Iain Hargreaves
- Neurometabolic Unit, National Hospital, Queen Square, London WC1N 3BG, UK
| | | | - John M. Land
- Neurometabolic Unit, National Hospital, Queen Square, London WC1N 3BG, UK
| | - Lee Stanyer
- Department of Molecular Neuroscience, UCL Institute of Neurology, London WC1N 3BG, UK
| | - Masayuki Yamamoto
- Department of Medical Biochemistry, Tohoku University Graduate School of Medicine, 2-1 Seiryo-cho, Aoba-ku, Sendai 980-8575, Japan
| | - Albena T. Dinkova-Kostova
- Jacqui Wood Cancer Centre, Division of Cancer Research, Medical Research Institute, University of Dundee, Dundee DD1 9SY, UK
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Andrey Y. Abramov
- Department of Molecular Neuroscience, UCL Institute of Neurology, London WC1N 3BG, UK
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11
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Clinical, biochemical, cellular and molecular characterization of mitochondrial DNA depletion syndrome due to novel mutations in the MPV17 gene. Eur J Hum Genet 2013; 22:184-91. [PMID: 23714749 PMCID: PMC3895632 DOI: 10.1038/ejhg.2013.112] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Revised: 04/15/2013] [Accepted: 04/17/2013] [Indexed: 11/29/2022] Open
Abstract
Mitochondrial DNA (mtDNA) depletion syndromes (MDS) are severe autosomal recessive disorders associated with decreased mtDNA copy number in clinically affected tissues. The hepatocerebral form (mtDNA depletion in liver and brain) has been associated with mutations in the POLG, PEO1 (Twinkle), DGUOK and MPV17 genes, the latter encoding a mitochondrial inner membrane protein of unknown function. The aims of this study were to clarify further the clinical, biochemical, cellular and molecular genetic features associated with MDS due to MPV17 gene mutations. We identified 12 pathogenic mutations in the MPV17 gene, of which 11 are novel, in 17 patients from 12 families. All patients manifested liver disease. Poor feeding, hypoglycaemia, raised serum lactate, hypotonia and faltering growth were common presenting features. mtDNA depletion in liver was demonstrated in all seven cases where liver tissue was available. Mosaic mtDNA depletion was found in primary fibroblasts by PicoGreen staining. These results confirm that MPV17 mutations are an important cause of hepatocerebral mtDNA depletion syndrome, and provide the first demonstration of mosaic mtDNA depletion in human MPV17 mutant fibroblast cultures. We found that a severe clinical phenotype was associated with profound tissue-specific mtDNA depletion in liver, and, in some cases, mosaic mtDNA depletion in fibroblasts.
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12
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Duberley KEC, Abramov AY, Chalasani A, Heales SJ, Rahman S, Hargreaves IP. Human neuronal coenzyme Q10 deficiency results in global loss of mitochondrial respiratory chain activity, increased mitochondrial oxidative stress and reversal of ATP synthase activity: implications for pathogenesis and treatment. J Inherit Metab Dis 2013; 36:63-73. [PMID: 22767283 DOI: 10.1007/s10545-012-9511-0] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2012] [Revised: 06/11/2012] [Accepted: 06/14/2012] [Indexed: 01/13/2023]
Abstract
Disorders of coenzyme Q(10) (CoQ(10)) biosynthesis represent the most treatable subgroup of mitochondrial diseases. Neurological involvement is frequently observed in CoQ(10) deficiency, typically presenting as cerebellar ataxia and/or seizures. The aetiology of the neurological presentation of CoQ(10) deficiency has yet to be fully elucidated and therefore in order to investigate these phenomena we have established a neuronal cell model of CoQ(10) deficiency by treatment of neuronal SH-SY5Y cell line with para-aminobenzoic acid (PABA). PABA is a competitive inhibitor of the CoQ(10) biosynthetic pathway enzyme, COQ2. PABA treatment (1 mM) resulted in a 54 % decrease (46 % residual CoQ(10)) decrease in neuronal CoQ(10) status (p < 0.01). Reduction of neuronal CoQ(10) status was accompanied by a progressive decrease in mitochondrial respiratory chain enzyme activities, with a 67.5 % decrease in cellular ATP production at 46 % residual CoQ(10). Mitochondrial oxidative stress increased four-fold at 77 % and 46 % residual CoQ(10). A 40 % increase in mitochondrial membrane potential was detected at 46 % residual CoQ(10) with depolarisation following oligomycin treatment suggesting a reversal of complex V activity. This neuronal cell model provides insights into the effects of CoQ(10) deficiency on neuronal mitochondrial function and oxidative stress, and will be an important tool to evaluate candidate therapies for neurological conditions associated with CoQ(10) deficiency.
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Affiliation(s)
- Kate E C Duberley
- Department of Molecular Neuroscience, UCL Institute of Neurology and Neurometabolic Unit, National Hospital for Neurology, Queen Square, London WC1N 3BG, UK.
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13
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Vettor R, Milan G, Franzin C, Sanna M, De Coppi P, Rizzuto R, Federspil G. The origin of intermuscular adipose tissue and its pathophysiological implications. Am J Physiol Endocrinol Metab 2009; 297:E987-98. [PMID: 19738037 DOI: 10.1152/ajpendo.00229.2009] [Citation(s) in RCA: 194] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The intermuscular adipose tissue (IMAT) is a depot of adipocytes located between muscle bundles. Several investigations have recently been carried out to define the phenotype, the functional characteristics, and the origin of the adipocytes present in this depot. Among the different mechanisms that could be responsible for the accumulation of fat in this site, the dysdifferentiation of muscle-derived stem cells or other mesenchymal progenitors has been postulated, turning them into cells with an adipocyte phenotype. In particular, muscle satellite cells (SCs), a heterogeneous stem cell population characterized by plasticity and self-renewal that allow muscular growth and regeneration, can acquire features of adipocytes, including the abilities to express adipocyte-specific genes and accumulate lipids. Failure to express the transcription factors that direct mesenchymal precursors into fully differentiated functionally specialized cells may be responsible for their phenotypic switch into the adipogenic lineage. We proved that human SCs also possess a clear adipogenic potential that could explain the presence of mature adipocytes within skeletal muscle. This occurs under some pathological conditions (i.e., primary myodystrophies, obesity, hyperglycemia, high plasma free fatty acids, hypoxia, etc.) or as a consequence of thiazolidinedione treatment or simply because of a sedentary lifestyle or during aging. Several pathways and factors (PPARs, WNT growth factors, myokines, GEF-GAP-Rho, p66(shc), mitochondrial ROS production, PKCβ) could be implicated in the adipogenic conversion of SCs. The understanding of the molecular pathways that regulate muscle-to-fat conversion and SC behavior could explain the increase in IMAT depots that characterize many metabolic diseases and age-related sarcopenia.
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Affiliation(s)
- Roberto Vettor
- Dept. of Medical and Surgical Sciences, Univ. of Padua, via Ospedale, 105, 35128 Padua, Italy.
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14
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Pawlikowska P, Gajkowska B, Hocquette J, Orzechowski A. Not only insulin stimulates mitochondriogenesis in muscle cells, but mitochondria are also essential for insulin-mediated myogenesis. Cell Prolif 2006; 39:127-45. [PMID: 16542348 PMCID: PMC6495419 DOI: 10.1111/j.1365-2184.2006.00376.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Viability and myogenesis from C2C12 muscle cells and L6 rat myoblasts were dose-dependently stimulated by insulin. The metabolic inhibitors of phosphatidyl-inositol-3-kinase (PI-3K, LY294002) and of MAPKK/ERK kinase (MEK, PD98059) differently affected insulin-stimulated myogenesis of the cells. After LY294002 and PD98059 treatment, viability deteriorated and apparently an additive effect of both metabolic inhibitors was observed, irrespective of the method of measurement (neutral red or MTT assay). These inhibitors were antagonistic in myogenesis. Our results confirm that insulin regulates cell viability by at least two distinct pathways, namely by PI-3K- and MEK-dependent signalling cascades. Both pathways are agonistic in cell viability, whereas PI-3K rather than MEK supports insulin-mediated myogenicity. Accordingly, inhibition of insulin action by LY294002, but not PD98059, was accompanied with a reduced level of Ser473-phosphorylated Akt with additional loss of myogenin protein. Besides, repression of insulin signalling by either PI-3K or MEK inhibitor diminished expression of selected subunits of the mitochondrial oxidative phosphorylation enzymes (OXPHOS). In turn, insulin raised and accelerated protein expression of subunits I and IV of mitochondrial cytochrome-c oxidase (COX). In addition, the level of myogenin, the molecular marker of terminal and general muscle differentiation indices decreased if selected OXPHOS enzymes were individually blocked by rotenone, myxothiazol or oligomycin. Summing up, our results pointed to mitochondria as an essential organelle for insulin-dependent myogenesis. Insulin positively affects mitochondrial function by induction of OXPHOS enzymes, which provide energy indispensable for the anabolic effect of insulin.
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Affiliation(s)
- Patrycja Pawlikowska
- Department of Physiological Sciences, Faculty of Veterinary Medicine, Warsaw Agricultural University, Nowoursynowska 159, 02‐776 Warsaw, Poland
| | - Barbara Gajkowska
- Department of Cell Ultrastructure MRC, Polish Academy of Sciences, Warsaw, Poland
| | - Jean‐François Hocquette
- Unité de Recherches sur les Herbivores, Equipe Croissance et Métabolisme du Muscle, INRA, Theix, 63122 Saint‐Genès Champanelle, France
| | - Arkadiusz Orzechowski
- Department of Physiological Sciences, Faculty of Veterinary Medicine, Warsaw Agricultural University, Nowoursynowska 159, 02‐776 Warsaw, Poland
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15
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Stewart VC, Stone R, Gegg ME, Sharpe MA, Hurst RD, Clark JB, Heales SJR. Preservation of extracellular glutathione by an astrocyte derived factor with properties comparable to extracellular superoxide dismutase. J Neurochem 2002; 83:984-91. [PMID: 12421371 DOI: 10.1046/j.1471-4159.2002.01216.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Cultured rat and human astrocytes and rat neurones were shown to release reduced glutathione (GSH). In addition, GSH oxidation was retarded by the concomitant release of a factor from the cells. One possibility is that this factor is extracellular superoxide dismutase (SOD). In support of this, the factor was found to bind heparin, have a molecular mass estimated to be between 50 and 100 kDa, and CuZn-type SOD protein and cyanide sensitive enzyme activity were demonstrated in the cell-conditioned medium. In addition, supplementation of native medium with exogenous CuZn-type SOD suppressed GSH oxidation. We propose that preservation of released GSH is essential to allow for maximal up-regulation of GSH metabolism in neurones. Furthermore, cytokine stimulation of astrocytes increased release of the extracellular SOD, and enhanced stability of GSH. This may be a protective strategy occurring in vivo under conditions of oxidative stress, and suggests that SOD mimetics may be of therapeutic use.
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Affiliation(s)
- Victoria C Stewart
- Department of Molecular Pathogenesis, Division of Neurochemistry, UCL, Institute of Neurology, London, UK
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