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van der Ven AT, Cabrera-Orefice A, Wente I, Feichtinger RG, Tsiakas K, Weiss D, Bierhals T, Scholle L, Prokisch H, Kopajtich R, Santer R, Mayr JA, Hempel M, Wittig I. Expanding the phenotypic and biochemical spectrum of NDUFAF3-related mitochondrial disease. Mol Genet Metab 2023; 140:107675. [PMID: 37572574 DOI: 10.1016/j.ymgme.2023.107675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 07/27/2023] [Accepted: 07/30/2023] [Indexed: 08/14/2023]
Abstract
Recessive variants in NDUFAF3 are a known cause of complex I (CI)-related mitochondrial disorders (MDs). The seven patients reported to date exhibited severe neurologic symptoms and lactic acidosis, followed by a fatal course and death during infancy in most cases. We present a 10-year-old patient with a neurodevelopmental disorder, progressive exercise intolerance, dystonia, basal ganglia abnormalities, and elevated lactate concentration in blood. Trio-exome sequencing revealed compound-heterozygosity for a pathogenic splice-site and a likely pathogenic missense variant in NDUFAF3. Spectrophotometric analysis of fibroblast-derived mitochondria demonstrated a relatively mild reduction of CI activity. Complexome analyses revealed severely reduced NDUFAF3 as well as CI in patient fibroblasts. Accumulation of early sub-assemblies of the membrane arm of CI associated with mitochondrial complex I intermediate assembly (MCIA) complex was observed. The most striking additional findings were both the unusual occurrence of free monomeric CI holding MCIA and other assembly factors. Here we discuss our patient in context of genotype, phenotype and metabolite data from previously reported NDUFAF3 cases. With the atypical presentation of our patient, we provide further insight into the phenotypic spectrum of NDUFAF3-related MDs. Complexome analysis in our patient confirms the previously defined role of NDUFAF3 within CI biogenesis, yet adds new aspects regarding the correct timing of both the association of soluble and membrane arm modules and CI-maturation as well as respiratory supercomplex formation.
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Affiliation(s)
- Amelie T van der Ven
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
| | - Alfredo Cabrera-Orefice
- Functional Proteomics, Institute of Cardiovascular Physiology, Goethe University, Frankfurt am Main, Germany
| | - Isabell Wente
- Functional Proteomics, Institute of Cardiovascular Physiology, Goethe University, Frankfurt am Main, Germany
| | - René G Feichtinger
- University Children's Hospital, Salzburger Landeskliniken (SALK) and Paracelsus Medical University (PMU), Salzburg, Austria
| | - Konstantinos Tsiakas
- Department of Pediatrics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Deike Weiss
- Department of Pediatrics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Tatjana Bierhals
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Leila Scholle
- Department of Neurology, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany
| | - Holger Prokisch
- Institute of Human Genetics, Klinikum Rechts der Isar, TUM, Munich, Germany.; Institute of Neurogenomics, Helmholtz Center Munich, Neuherberg, Germany
| | - Robert Kopajtich
- Institute of Human Genetics, Klinikum Rechts der Isar, TUM, Munich, Germany.; Institute of Neurogenomics, Helmholtz Center Munich, Neuherberg, Germany
| | - René Santer
- Department of Pediatrics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Johannes A Mayr
- University Children's Hospital, Salzburger Landeskliniken (SALK) and Paracelsus Medical University (PMU), Salzburg, Austria
| | - Maja Hempel
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; Institute of Human Genetics, University Hospital Heidelberg, Heidelberg, Germany
| | - Ilka Wittig
- Functional Proteomics, Institute of Cardiovascular Physiology, Goethe University, Frankfurt am Main, Germany
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Čunátová K, Reguera DP, Vrbacký M, Fernández-Vizarra E, Ding S, Fearnley IM, Zeviani M, Houštěk J, Mráček T, Pecina P. Loss of COX4I1 Leads to Combined Respiratory Chain Deficiency and Impaired Mitochondrial Protein Synthesis. Cells 2021; 10:369. [PMID: 33578848 PMCID: PMC7916595 DOI: 10.3390/cells10020369] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 02/02/2021] [Accepted: 02/04/2021] [Indexed: 01/07/2023] Open
Abstract
The oxidative phosphorylation (OXPHOS) system localized in the inner mitochondrial membrane secures production of the majority of ATP in mammalian organisms. Individual OXPHOS complexes form supramolecular assemblies termed supercomplexes. The complexes are linked not only by their function but also by interdependency of individual complex biogenesis or maintenance. For instance, cytochrome c oxidase (cIV) or cytochrome bc1 complex (cIII) deficiencies affect the level of fully assembled NADH dehydrogenase (cI) in monomeric as well as supercomplex forms. It was hypothesized that cI is affected at the level of enzyme assembly as well as at the level of cI stability and maintenance. However, the true nature of interdependency between cI and cIV is not fully understood yet. We used a HEK293 cellular model where the COX4 subunit was completely knocked out, serving as an ideal system to study interdependency of cI and cIV, as early phases of cIV assembly process were disrupted. Total absence of cIV was accompanied by profound deficiency of cI, documented by decrease in the levels of cI subunits and significantly reduced amount of assembled cI. Supercomplexes assembled from cI, cIII, and cIV were missing in COX4I1 knock-out (KO) due to loss of cIV and decrease in cI amount. Pulse-chase metabolic labeling of mitochondrial DNA (mtDNA)-encoded proteins uncovered a decrease in the translation of cIV and cI subunits. Moreover, partial impairment of mitochondrial protein synthesis correlated with decreased content of mitochondrial ribosomal proteins. In addition, complexome profiling revealed accumulation of cI assembly intermediates, indicating that cI biogenesis, rather than stability, was affected. We propose that attenuation of mitochondrial protein synthesis caused by cIV deficiency represents one of the mechanisms, which may impair biogenesis of cI.
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Affiliation(s)
- Kristýna Čunátová
- Laboratory of Bioenergetics, Institute of Physiology, Czech Academy of Sciences, 142 00 Prague, Czech Republic; (K.Č.); (D.P.R.); (M.V.); (J.H.)
- Department of Cell Biology, Faculty of Science, Charles University, 128 00 Prague, Czech Republic
| | - David Pajuelo Reguera
- Laboratory of Bioenergetics, Institute of Physiology, Czech Academy of Sciences, 142 00 Prague, Czech Republic; (K.Č.); (D.P.R.); (M.V.); (J.H.)
| | - Marek Vrbacký
- Laboratory of Bioenergetics, Institute of Physiology, Czech Academy of Sciences, 142 00 Prague, Czech Republic; (K.Č.); (D.P.R.); (M.V.); (J.H.)
| | - Erika Fernández-Vizarra
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, CB2 0XY, UK; (E.F.-V.); (S.D.); (I.M.F.); (M.Z.)
| | - Shujing Ding
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, CB2 0XY, UK; (E.F.-V.); (S.D.); (I.M.F.); (M.Z.)
| | - Ian M. Fearnley
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, CB2 0XY, UK; (E.F.-V.); (S.D.); (I.M.F.); (M.Z.)
| | - Massimo Zeviani
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, CB2 0XY, UK; (E.F.-V.); (S.D.); (I.M.F.); (M.Z.)
| | - Josef Houštěk
- Laboratory of Bioenergetics, Institute of Physiology, Czech Academy of Sciences, 142 00 Prague, Czech Republic; (K.Č.); (D.P.R.); (M.V.); (J.H.)
| | - Tomáš Mráček
- Laboratory of Bioenergetics, Institute of Physiology, Czech Academy of Sciences, 142 00 Prague, Czech Republic; (K.Č.); (D.P.R.); (M.V.); (J.H.)
| | - Petr Pecina
- Laboratory of Bioenergetics, Institute of Physiology, Czech Academy of Sciences, 142 00 Prague, Czech Republic; (K.Č.); (D.P.R.); (M.V.); (J.H.)
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Aminzadeh-Gohari S, Weber DD, Catalano L, Feichtinger RG, Kofler B, Lang R. Targeting Mitochondria in Melanoma. Biomolecules 2020; 10:biom10101395. [PMID: 33007949 PMCID: PMC7599575 DOI: 10.3390/biom10101395] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 09/23/2020] [Accepted: 09/28/2020] [Indexed: 12/13/2022] Open
Abstract
Drastically elevated glycolytic activity is a prominent metabolic feature of cancer cells. Until recently it was thought that tumor cells shift their entire energy production from oxidative phosphorylation (OXPHOS) to glycolysis. However, new evidence indicates that many cancer cells still have functional OXPHOS, despite their increased reliance on glycolysis. Growing pre-clinical and clinical evidence suggests that targeting mitochondrial metabolism has anti-cancer effects. Here, we analyzed mitochondrial respiration and the amount and activity of OXPHOS complexes in four melanoma cell lines and normal human dermal fibroblasts (HDFs) by Seahorse real-time cell metabolic analysis, immunoblotting, and spectrophotometry. We also tested three clinically approved antibiotics, one anti-parasitic drug (pyrvinium pamoate), and a novel anti-cancer agent (ONC212) for effects on mitochondrial respiration and proliferation of melanoma cells and HDFs. We found that three of the four melanoma cell lines have elevated glycolysis as well as OXPHOS, but contain dysfunctional mitochondria. The antibiotics produced different effects on the melanoma cells and HDFs. The anti-parasitic drug strongly inhibited respiration and proliferation of both the melanoma cells and HDFs. ONC212 reduced respiration in melanoma cells and HDFs, and inhibited the proliferation of melanoma cells. Our findings highlight ONC212 as a promising drug for targeting mitochondrial respiration in cancer.
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Affiliation(s)
- Sepideh Aminzadeh-Gohari
- Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, University Hospital of the Paracelsus Medical University, 5020 Salzburg, Austria; (S.A.-G.); (D.D.W.); (L.C.); (R.G.F.)
| | - Daniela D. Weber
- Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, University Hospital of the Paracelsus Medical University, 5020 Salzburg, Austria; (S.A.-G.); (D.D.W.); (L.C.); (R.G.F.)
| | - Luca Catalano
- Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, University Hospital of the Paracelsus Medical University, 5020 Salzburg, Austria; (S.A.-G.); (D.D.W.); (L.C.); (R.G.F.)
| | - René G. Feichtinger
- Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, University Hospital of the Paracelsus Medical University, 5020 Salzburg, Austria; (S.A.-G.); (D.D.W.); (L.C.); (R.G.F.)
| | - Barbara Kofler
- Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, University Hospital of the Paracelsus Medical University, 5020 Salzburg, Austria; (S.A.-G.); (D.D.W.); (L.C.); (R.G.F.)
- Correspondence: (B.K.); (R.L.); Tel.: +43-57255-26274 (B.K.); +43-57255-58200 (R.L.)
| | - Roland Lang
- Department of Dermatology and Allergology, University Hospital of the Paracelsus Medical University, 5020 Salzburg, Austria
- Correspondence: (B.K.); (R.L.); Tel.: +43-57255-26274 (B.K.); +43-57255-58200 (R.L.)
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Pecinová A, Alán L, Brázdová A, Vrbacký M, Pecina P, Drahota Z, Houštěk J, Mráček T. Role of Mitochondrial Glycerol-3-Phosphate Dehydrogenase in Metabolic Adaptations of Prostate Cancer. Cells 2020; 9:cells9081764. [PMID: 32717855 PMCID: PMC7464303 DOI: 10.3390/cells9081764] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 07/14/2020] [Accepted: 07/22/2020] [Indexed: 12/26/2022] Open
Abstract
Prostate cancer is one of the most prominent cancers diagnosed in males. Contrasting with other cancer types, glucose utilization is not increased in prostate carcinoma cells as they employ different metabolic adaptations involving mitochondria as a source of energy and intermediates required for rapid cell growth. In this regard, prostate cancer cells were associated with higher activity of mitochondrial glycerol-3-phosphate dehydrogenase (mGPDH), the key rate limiting component of the glycerophosphate shuttle, which connects mitochondrial and cytosolic processes and plays significant role in cellular bioenergetics. Our research focused on the role of mGPDH biogenesis and regulation in prostate cancer compared to healthy cells. We show that the 42 amino acid presequence is cleaved from N-terminus during mGPDH biogenesis. Only the processed form is part of the mGPDH dimer that is the prominent functional enzyme entity. We demonstrate that mGPDH overexpression enhances the wound healing ability in prostate cancer cells. As mGPDH is at the crossroad of glycolysis, lipogenesis and oxidative metabolism, regulation of its activity by intramitochondrial processing might represent rapid means of cellular metabolic adaptations.
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Pajuelo Reguera D, Čunátová K, Vrbacký M, Pecinová A, Houštěk J, Mráček T, Pecina P. Cytochrome c Oxidase Subunit 4 Isoform Exchange Results in Modulation of Oxygen Affinity. Cells 2020; 9:cells9020443. [PMID: 32075102 PMCID: PMC7072730 DOI: 10.3390/cells9020443] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 02/11/2020] [Accepted: 02/11/2020] [Indexed: 01/05/2023] Open
Abstract
Cytochrome c oxidase (COX) is regulated through tissue-, development- or environment-controlled expression of subunit isoforms. The COX4 subunit is thought to optimize respiratory chain function according to oxygen-controlled expression of its isoforms COX4i1 and COX4i2. However, biochemical mechanisms of regulation by the two variants are only partly understood. We created an HEK293-based knock-out cellular model devoid of both isoforms (COX4i1/2 KO). Subsequent knock-in of COX4i1 or COX4i2 generated cells with exclusive expression of respective isoform. Both isoforms complemented the respiratory defect of COX4i1/2 KO. The content, composition, and incorporation of COX into supercomplexes were comparable in COX4i1- and COX4i2-expressing cells. Also, COX activity, cytochrome c affinity, and respiratory rates were undistinguishable in cells expressing either isoform. Analysis of energy metabolism and the redox state in intact cells uncovered modestly increased preference for mitochondrial ATP production, consistent with the increased NADH pool oxidation and lower ROS in COX4i2-expressing cells in normoxia. Most remarkable changes were uncovered in COX oxygen kinetics. The p50 (partial pressure of oxygen at half-maximal respiration) was increased twofold in COX4i2 versus COX4i1 cells, indicating decreased oxygen affinity of the COX4i2-containing enzyme. Our finding supports the key role of the COX4i2-containing enzyme in hypoxia-sensing pathways of energy metabolism.
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Affiliation(s)
- David Pajuelo Reguera
- Department of Bioenergetics, Institute of Physiology, Czech Academy of Sciences, 14220 Prague 4, Czech Republic; (D.P.R.); (K.Č.); (M.V.); (A.P.); (J.H.)
| | - Kristýna Čunátová
- Department of Bioenergetics, Institute of Physiology, Czech Academy of Sciences, 14220 Prague 4, Czech Republic; (D.P.R.); (K.Č.); (M.V.); (A.P.); (J.H.)
- Department of Cell Biology, Faculty of Science, Charles University, 12000 Prague 2, Czech Republic
| | - Marek Vrbacký
- Department of Bioenergetics, Institute of Physiology, Czech Academy of Sciences, 14220 Prague 4, Czech Republic; (D.P.R.); (K.Č.); (M.V.); (A.P.); (J.H.)
| | - Alena Pecinová
- Department of Bioenergetics, Institute of Physiology, Czech Academy of Sciences, 14220 Prague 4, Czech Republic; (D.P.R.); (K.Č.); (M.V.); (A.P.); (J.H.)
| | - Josef Houštěk
- Department of Bioenergetics, Institute of Physiology, Czech Academy of Sciences, 14220 Prague 4, Czech Republic; (D.P.R.); (K.Č.); (M.V.); (A.P.); (J.H.)
| | - Tomáš Mráček
- Department of Bioenergetics, Institute of Physiology, Czech Academy of Sciences, 14220 Prague 4, Czech Republic; (D.P.R.); (K.Č.); (M.V.); (A.P.); (J.H.)
- Correspondence: (T.M.); (P.P.)
| | - Petr Pecina
- Department of Bioenergetics, Institute of Physiology, Czech Academy of Sciences, 14220 Prague 4, Czech Republic; (D.P.R.); (K.Č.); (M.V.); (A.P.); (J.H.)
- Correspondence: (T.M.); (P.P.)
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Kennedy H, Haack T, Hartill V, Mataković L, Baumgartner E, Potter H, Mackay R, Alston C, O’Sullivan S, McFarland R, Connolly G, Gannon C, King R, Mead S, Crozier I, Chan W, Florkowski C, Sage M, Höfken T, Alhaddad B, Kremer L, Kopajtich R, Feichtinger R, Sperl W, Rodenburg R, Minet J, Dobbie A, Strom T, Meitinger T, George P, Johnson C, Taylor R, Prokisch H, Doudney K, Mayr J. Sudden Cardiac Death Due to Deficiency of the Mitochondrial Inorganic Pyrophosphatase PPA2. Am J Hum Genet 2016; 99:674-682. [PMID: 27523597 PMCID: PMC5011043 DOI: 10.1016/j.ajhg.2016.06.027] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 06/27/2016] [Indexed: 11/28/2022] Open
Abstract
We have used whole-exome sequencing in ten individuals from four unrelated pedigrees to identify biallelic missense mutations in the nuclear-encoded mitochondrial inorganic pyrophosphatase (PPA2) that are associated with mitochondrial disease. These individuals show a range of severity, indicating that PPA2 mutations may cause a spectrum of mitochondrial disease phenotypes. Severe symptoms include seizures, lactic acidosis, cardiac arrhythmia, and death within days of birth. In the index family, presentation was milder and manifested as cardiac fibrosis and an exquisite sensitivity to alcohol, leading to sudden arrhythmic cardiac death in the second decade of life. Comparison of normal and mutant PPA2-containing mitochondria from fibroblasts showed that the activity of inorganic pyrophosphatase was significantly reduced in affected individuals. Recombinant PPA2 enzymes modeling hypomorphic missense mutations had decreased activity that correlated with disease severity. These findings confirm the pathogenicity of PPA2 mutations and suggest that PPA2 is a cardiomyopathy-associated protein, which has a greater physiological importance in mitochondrial function than previously recognized.
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Hartmannová H, Piherová L, Tauchmannová K, Kidd K, Acott PD, Crocker JFS, Oussedik Y, Mallet M, Hodaňová K, Stránecký V, Přistoupilová A, Barešová V, Jedličková I, Živná M, Sovová J, Hůlková H, Robins V, Vrbacký M, Pecina P, Kaplanová V, Houštěk J, Mráček T, Thibeault Y, Bleyer AJ, Kmoch S. Acadian variant of Fanconi syndrome is caused by mitochondrial respiratory chain complex I deficiency due to a non-coding mutation in complex I assembly factor NDUFAF6. Hum Mol Genet 2016; 25:4062-4079. [DOI: 10.1093/hmg/ddw245] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 07/11/2016] [Accepted: 07/11/2016] [Indexed: 12/12/2022] Open
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Kovářová N, Pecina P, Nůsková H, Vrbacký M, Zeviani M, Mráček T, Viscomi C, Houštěk J. Data on cytochrome c oxidase assembly in mice and human fibroblasts or tissues induced by SURF1 defect. Data Brief 2016; 7:1004-9. [PMID: 27408912 PMCID: PMC4927972 DOI: 10.1016/j.dib.2016.03.065] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Revised: 03/03/2016] [Accepted: 03/18/2016] [Indexed: 11/13/2022] Open
Abstract
This paper describes data related to a research article entitled “Tissue- and species-specific differences in cytochrome c oxidase assembly induced by SURF1 defects” [1]. This paper includes data of the quantitative analysis of individual forms of respiratory chain complexes I, III and IV present in SURF1 knockout (SURF1−/−) and control (SURF1+/+) mouse fibroblasts and tissues and in fibroblasts of human control and patients with SURF1 gene mutation. Also it includes data demonstrating response of complex IV, cytochrome c oxidase (COX), to reversible inhibition of mitochondrial translation in SURF1−/− mouse and SURF1 patient fibroblast cell lines.
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Affiliation(s)
- Nikola Kovářová
- Institute of Physiology of the Czech Academy of Sciences, Vídeňská 1083, Prague, Czech Republic
| | - Petr Pecina
- Institute of Physiology of the Czech Academy of Sciences, Vídeňská 1083, Prague, Czech Republic
| | - Hana Nůsková
- Institute of Physiology of the Czech Academy of Sciences, Vídeňská 1083, Prague, Czech Republic
| | - Marek Vrbacký
- Institute of Physiology of the Czech Academy of Sciences, Vídeňská 1083, Prague, Czech Republic
| | - Massimo Zeviani
- Molecular Neurogenetics Unit, Instituto Neurologico "C. Besta", via Temolo 4, 20126 Milan, Italy; MRC-Mitochondrial Biology Unit, Wellcome Trust MRC Bldg, Addenbrookes Hospital Hills Rd, Cambridge CB2 0XY, UK
| | - Tomáš Mráček
- Institute of Physiology of the Czech Academy of Sciences, Vídeňská 1083, Prague, Czech Republic
| | - Carlo Viscomi
- MRC-Mitochondrial Biology Unit, Wellcome Trust MRC Bldg, Addenbrookes Hospital Hills Rd, Cambridge CB2 0XY, UK
| | - Josef Houštěk
- Institute of Physiology of the Czech Academy of Sciences, Vídeňská 1083, Prague, Czech Republic
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Kovářová N, Pecina P, Nůsková H, Vrbacký M, Zeviani M, Mráček T, Viscomi C, Houštěk J. Tissue- and species-specific differences in cytochrome c oxidase assembly induced by SURF1 defects. Biochim Biophys Acta Mol Basis Dis 2016; 1862:705-715. [PMID: 26804654 PMCID: PMC4793088 DOI: 10.1016/j.bbadis.2016.01.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 12/08/2015] [Accepted: 01/08/2016] [Indexed: 12/17/2022]
Abstract
Mitochondrial protein SURF1 is a specific assembly factor of cytochrome c oxidase (COX), but its function is poorly understood. SURF1 gene mutations cause a severe COX deficiency manifesting as the Leigh syndrome in humans, whereas in mice SURF1−/− knockout leads only to a mild COX defect. We used SURF1−/− mouse model for detailed analysis of disturbed COX assembly and COX ability to incorporate into respiratory supercomplexes (SCs) in different tissues and fibroblasts. Furthermore, we compared fibroblasts from SURF1−/− mouse and SURF1 patients to reveal interspecies differences in kinetics of COX biogenesis using 2D electrophoresis, immunodetection, arrest of mitochondrial proteosynthesis and pulse-chase metabolic labeling. The crucial differences observed are an accumulation of abundant COX1 assembly intermediates, low content of COX monomer and preferential recruitment of COX into I–III2–IVn SCs in SURF1 patient fibroblasts, whereas SURF1−/− mouse fibroblasts were characterized by low content of COX1 assembly intermediates and milder decrease in COX monomer, which appeared more stable. This pattern was even less pronounced in SURF1−/− mouse liver and brain. Both the control and SURF1−/− mice revealed only negligible formation of the I–III2–IVn SCs and marked tissue differences in the contents of COX dimer and III2–IV SCs, also less noticeable in liver and brain than in heart and muscle. Our studies support the view that COX assembly is much more dependent on SURF1 in humans than in mice. We also demonstrate markedly lower ability of mouse COX to form I–III2–IVn supercomplexes, pointing to tissue-specific and species-specific differences in COX biogenesis. In SURF1 −/− mouse the decrease of COX amount and activity was tissue/cell specific. Assembly kinetics proceeded to the level of stable COX monomer in SURF1 −/− mouse. COX assembly intermediates were faster degraded/depleted in time in SURF1 −/− mouse. COX was preferentially recruited in supercomplex I–III2–IV1 in SURF1 patient cells. Newly synthesized COX monomer was unstable and rapidly degraded in SURF1 patient.
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Affiliation(s)
- Nikola Kovářová
- Institute of Physiology of the Czech Academy of Sciences, Vídeňská 1083, Prague, Czech Republic
| | - Petr Pecina
- Institute of Physiology of the Czech Academy of Sciences, Vídeňská 1083, Prague, Czech Republic
| | - Hana Nůsková
- Institute of Physiology of the Czech Academy of Sciences, Vídeňská 1083, Prague, Czech Republic
| | - Marek Vrbacký
- Institute of Physiology of the Czech Academy of Sciences, Vídeňská 1083, Prague, Czech Republic
| | - Massimo Zeviani
- Molecular Neurogenetics Unit, Instituto Neurologico "C. Besta", via Temolo 4, 20126 Milan, Italy; MRC-Mitochondrial Biology Unit, Wellcome Trust MRC Bldg, Addenbrookes Hospital Hills Rd, Cambridge CB2 0XY, UK
| | - Tomáš Mráček
- Institute of Physiology of the Czech Academy of Sciences, Vídeňská 1083, Prague, Czech Republic
| | - Carlo Viscomi
- MRC-Mitochondrial Biology Unit, Wellcome Trust MRC Bldg, Addenbrookes Hospital Hills Rd, Cambridge CB2 0XY, UK
| | - Josef Houštěk
- Institute of Physiology of the Czech Academy of Sciences, Vídeňská 1083, Prague, Czech Republic.
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Alteration of structure and function of ATP synthase and cytochrome c oxidase by lack of Fo-a and Cox3 subunits caused by mitochondrial DNA 9205delTA mutation. Biochem J 2015; 466:601-11. [PMID: 25588698 DOI: 10.1042/bj20141462] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Mutations in the MT-ATP6 gene are frequent causes of severe mitochondrial disorders. Typically, these are missense mutations, but another type is represented by the 9205delTA microdeletion, which removes the stop codon of the MT-ATP6 gene and affects the cleavage site in the MT-ATP8/MT-ATP6/MT-CO3 polycistronic transcript. This interferes with the processing of mRNAs for the Atp6 (Fo-a) subunit of ATP synthase and the Cox3 subunit of cytochrome c oxidase (COX). Two cases described so far presented with strikingly different clinical phenotypes-mild transient lactic acidosis or fatal encephalopathy. To gain more insight into the pathogenic mechanism, we prepared 9205delTA cybrids with mutation load ranging between 52 and 99% and investigated changes in the structure and function of ATP synthase and the COX. We found that 9205delTA mutation strongly reduces the levels of both Fo-a and Cox3 proteins. Lack of Fo-a alters the structure but not the content of ATP synthase, which assembles into a labile, ∼60 kDa smaller, complex retaining ATP hydrolytic activity but which is unable to synthesize ATP. In contrast, lack of Cox3 limits the biosynthesis of COX but does not alter the structure of the enzyme. Consequently, the diminished mitochondrial content of COX and non-functional ATP synthase prevent most mitochondrial ATP production. The biochemical effects caused by the 9205delTA microdeletion displayed a pronounced threshold effect above ∼90% mutation heteroplasmy. We observed a linear relationship between the decrease in subunit Fo-a or Cox3 content and the functional presentation of the defect. Therefore we conclude that the threshold effect originated from a gene-protein level.
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Kratochvílová H, Hejzlarová K, Vrbacký M, Mráček T, Karbanová V, Tesařová M, Gombitová A, Cmarko D, Wittig I, Zeman J, Houštěk J. Mitochondrial membrane assembly of TMEM70 protein. Mitochondrion 2014; 15:1-9. [DOI: 10.1016/j.mito.2014.02.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Revised: 02/04/2014] [Accepted: 02/18/2014] [Indexed: 01/09/2023]
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12
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High molecular weight forms of mammalian respiratory chain complex II. PLoS One 2013; 8:e71869. [PMID: 23967256 PMCID: PMC3742469 DOI: 10.1371/journal.pone.0071869] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Accepted: 07/10/2013] [Indexed: 12/17/2022] Open
Abstract
Mitochondrial respiratory chain is organised into supramolecular structures that can be preserved in mild detergent solubilisates and resolved by native electrophoretic systems. Supercomplexes of respiratory complexes I, III and IV as well as multimeric forms of ATP synthase are well established. However, the involvement of complex II, linking respiratory chain with tricarboxylic acid cycle, in mitochondrial supercomplexes is questionable. Here we show that digitonin-solubilised complex II quantitatively forms high molecular weight structures (CIIhmw) that can be resolved by clear native electrophoresis. CIIhmw structures are enzymatically active and differ in electrophoretic mobility between tissues (500 – over 1000 kDa) and cultured cells (400–670 kDa). While their formation is unaffected by isolated defects in other respiratory chain complexes, they are destabilised in mtDNA-depleted, rho0 cells. Molecular interactions responsible for the assembly of CIIhmw are rather weak with the complexes being more stable in tissues than in cultured cells. While electrophoretic studies and immunoprecipitation experiments of CIIhmw do not indicate specific interactions with the respiratory chain complexes I, III or IV or enzymes of the tricarboxylic acid cycle, they point out to a specific interaction between CII and ATP synthase.
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13
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Mueller EE, Brunner SM, Mayr JA, Stanger O, Sperl W, Kofler B. Functional differences between mitochondrial haplogroup T and haplogroup H in HEK293 cybrid cells. PLoS One 2012; 7:e52367. [PMID: 23300652 PMCID: PMC3530588 DOI: 10.1371/journal.pone.0052367] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Accepted: 11/15/2012] [Indexed: 12/20/2022] Open
Abstract
Background Epidemiological case-control studies have revealed associations between mitochondrial haplogroups and the onset and/or progression of various multifactorial diseases. For instance, mitochondrial haplogroup T was previously shown to be associated with vascular diseases, including coronary artery disease and diabetic retinopathy. In contrast, haplogroup H, the most frequent haplogroup in Europe, is often found to be more prevalent in healthy control subjects than in patient study groups. However, justifications for the assumption that haplogroups are functionally distinct are rare. Therefore, we attempted to compare differences in mitochondrial function between haplogroup H and T cybrids. Methodology/Principal Findings Mitochondrial haplogroup H and T cybrids were generated by fusion of HEK293 cells devoid of mitochondrial DNA with isolated thrombocytes of individuals with the respective haplogroups. These cybrid cells were analyzed for oxidative phosphorylation (OXPHOS) enzyme activities, mitochondrial DNA (mtDNA) copy number, growth rate and susceptibility to reactive oxygen species (ROS). We observed that haplogroup T cybrids have higher survival rate when challenged with hydrogen peroxide, indicating a higher capability to cope with oxidative stress. Conclusions/Significance The results of this study show that functional differences exist between HEK293 cybrid cells which differ in mitochondrial genomic background.
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Affiliation(s)
- Edith E. Mueller
- Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, Paracelsus Medical University, Salzburg, Austria
| | - Susanne M. Brunner
- Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, Paracelsus Medical University, Salzburg, Austria
| | - Johannes A. Mayr
- Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, Paracelsus Medical University, Salzburg, Austria
| | - Olaf Stanger
- Department of Cardiac Surgery, Paracelsus Medical University, Salzburg, Austria
| | - Wolfgang Sperl
- Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, Paracelsus Medical University, Salzburg, Austria
| | - Barbara Kofler
- Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, Paracelsus Medical University, Salzburg, Austria
- * E-mail:
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14
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Koene S, Rodenburg RJ, van der Knaap MS, Willemsen MAAP, Sperl W, Laugel V, Ostergaard E, Tarnopolsky M, Martin MA, Nesbitt V, Fletcher J, Edvardson S, Procaccio V, Slama A, van den Heuvel LPWJ, Smeitink JAM. Natural disease course and genotype-phenotype correlations in Complex I deficiency caused by nuclear gene defects: what we learned from 130 cases. J Inherit Metab Dis 2012; 35:737-47. [PMID: 22644603 PMCID: PMC3432203 DOI: 10.1007/s10545-012-9492-z] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Revised: 04/13/2012] [Accepted: 04/16/2012] [Indexed: 11/29/2022]
Abstract
Mitochondrial complex I is the largest multi-protein enzyme complex of the oxidative phosphorylation system. Seven subunits of this complex are encoded by the mitochondrial and the remainder by the nuclear genome. We review the natural disease course and signs and symptoms of 130 patients (four new cases and 126 from literature) with mutations in nuclear genes encoding structural complex I proteins or those involved in its assembly. Complex I deficiency caused by a nuclear gene defect is usually a non-dysmorphic syndrome, characterized by severe multi-system organ involvement and a poor prognosis. Age at presentation may vary, but is generally within the first year of life. The most prevalent symptoms include hypotonia, nystagmus, respiratory abnormalities, pyramidal signs, dystonia, psychomotor retardation or regression, failure to thrive, and feeding problems. Characteristic symptoms include brainstem involvement, optic atrophy and Leigh syndrome on MRI, either or not in combination with internal organ involvement and lactic acidemia. Virtually all children ultimately develop Leigh syndrome or leukoencephalopathy. Twenty-five percent of the patients died before the age of six months, more than half before the age of two and 75 % before the age of ten years. Some patients showed recovery of certain skills or are still alive in their thirties . No clinical, biochemical, or genetic parameters indicating longer survival were found. No clear genotype-phenotype correlations were observed, however defects in some genes seem to be associated with a better or poorer prognosis, cardiomyopathy, Leigh syndrome or brainstem lesions.
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Affiliation(s)
- S Koene
- Nijmegen Centre for Mitochondrial Disorders, Institute for Genetic and Metabolic Disease, Radboud University Nijmegen Medical Centre, Geert Grooteplein 10, 6500 HB PO BOX 9101, Nijmegen, The Netherlands.
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15
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Compensatory upregulation of respiratory chain complexes III and IV in isolated deficiency of ATP synthase due to TMEM70 mutation. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2012; 1817:1037-43. [DOI: 10.1016/j.bbabio.2012.03.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2011] [Revised: 03/04/2012] [Accepted: 03/05/2012] [Indexed: 11/15/2022]
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16
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Adaptation of respiratory chain biogenesis to cytochrome c oxidase deficiency caused by SURF1 gene mutations. Biochim Biophys Acta Mol Basis Dis 2012; 1822:1114-24. [PMID: 22465034 DOI: 10.1016/j.bbadis.2012.03.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2011] [Revised: 03/09/2012] [Accepted: 03/12/2012] [Indexed: 01/26/2023]
Abstract
The loss of Surf1 protein leads to a severe COX deficiency manifested as a fatal neurodegenerative disorder, the Leigh syndrome (LS(COX)). Surf1 appears to be involved in the early step of COX assembly but its function remains unknown. The aim of the study was to find out how SURF1 gene mutations influence expression of OXPHOS and other pro-mitochondrial genes and to further characterize the altered COX assembly. Analysis of fibroblast cell lines from 9 patients with SURF1 mutations revealed a 70% decrease of the COX complex content to be associated with 32-54% upregulation of respiratory chain complexes I, III and V and accumulation of Cox5a subunit. Whole genome expression profiling showed a general decrease of transcriptional activity in LS(COX) cells and indicated that the adaptive changes in OXPHOS complexes are due to a posttranscriptional compensatory mechanism. Electrophoretic and WB analysis showed that in mitochondria of LS(COX) cells compared to controls, the assembled COX is present entirely in a supercomplex form, as I-III₂-IV supercomplex but not as larger supercomplexes. The lack of COX also caused an accumulation of I-III₂ supercomplex. The accumulated Cox5a was mainly present as a free subunit. We have found out that the major COX assembly subcomplexes accumulated due to SURF1 mutations range in size between approximately 85-140kDa. In addition to the originally proposed S2 intermediate they might also represent Cox1-containing complexes lacking other COX subunits. Unlike the assembled COX, subcomplexes are unable to associate with complexes I and III.
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17
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Mueller EE, Mayr JA, Zimmermann FA, Feichtinger RG, Stanger O, Sperl W, Kofler B. Reduction of nuclear encoded enzymes of mitochondrial energy metabolism in cells devoid of mitochondrial DNA. Biochem Biophys Res Commun 2011; 417:1052-7. [PMID: 22222373 DOI: 10.1016/j.bbrc.2011.12.093] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2011] [Accepted: 12/19/2011] [Indexed: 11/29/2022]
Abstract
Mitochondrial DNA (mtDNA) depletion syndromes are generally associated with reduced activities of oxidative phosphorylation (OXPHOS) enzymes that contain subunits encoded by mtDNA. Conversely, entirely nuclear encoded mitochondrial enzymes in these syndromes, such as the tricarboxylic acid cycle enzyme citrate synthase (CS) and OXPHOS complex II, usually exhibit normal or compensatory enhanced activities. Here we report that a human cell line devoid of mtDNA (HEK293 ρ(0) cells) has diminished activities of both complex II and CS. This finding indicates the existence of a feedback mechanism in ρ(0) cells that downregulates the expression of entirely nuclear encoded components of mitochondrial energy metabolism.
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Affiliation(s)
- Edith E Mueller
- Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, Salzburg, Austria.
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18
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Mayr JA, Bodamer O, Haack TB, Zimmermann FA, Madignier F, Prokisch H, Rauscher C, Koch J, Sperl W. Heterozygous mutation in the X chromosomal NDUFA1 gene in a girl with complex I deficiency. Mol Genet Metab 2011; 103:358-61. [PMID: 21596602 DOI: 10.1016/j.ymgme.2011.04.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2011] [Revised: 04/22/2011] [Accepted: 04/22/2011] [Indexed: 10/18/2022]
Abstract
Respiratory chain enzymes consist of multiple subunits encoded either by the mitochondrial or by the nuclear genome. Recently the first X-chromosomal mutations in complex I deficient males have been described. Heterozygous female carriers did not seem to be affected. Here, we describe a girl initially presenting with mild muscular hypotonia, a moderate lactic acidosis and an increased beta-hydroxybutyrate/acetoacetate ratio. Biochemical investigations of a muscle biopsy revealed a deficiency in the amount and activity of complex I. Mutation screening of all structural subunits of complex I identified a heterozygous mutation c.94G>C, p.Gly32Arg in the X-chromosomal NDUFA1 gene. Analysis of the cDNA showed that 72% of the expressed mRNA was mutated in the muscle biopsy sample. Investigation of the X-inactivation pattern demonstrated that 74% of the paternally inherited allele was active in the muscle. This is the first report of an X-chromosomally inherited respiratory chain defect in a heterozygous female.
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Affiliation(s)
- Johannes A Mayr
- Department of Pediatrics, Paracelsus Medical University, Salzburg, Austria.
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19
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Expression and processing of the TMEM70 protein. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2011; 1807:144-9. [DOI: 10.1016/j.bbabio.2010.10.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2010] [Revised: 09/30/2010] [Accepted: 10/05/2010] [Indexed: 11/18/2022]
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20
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Mayr JA, Havlícková V, Zimmermann F, Magler I, Kaplanová V, Jesina P, Pecinová A, Nusková H, Koch J, Sperl W, Houstek J. Mitochondrial ATP synthase deficiency due to a mutation in the ATP5E gene for the F1 epsilon subunit. Hum Mol Genet 2010; 19:3430-9. [PMID: 20566710 DOI: 10.1093/hmg/ddq254] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2023] Open
Abstract
F1Fo-ATP synthase is a key enzyme of mitochondrial energy provision producing most of cellular ATP. So far, mitochondrial diseases caused by isolated disorders of the ATP synthase have been shown to result from mutations in mtDNA genes for the subunits ATP6 and ATP8 or in nuclear genes encoding the biogenesis factors TMEM70 and ATPAF2. Here, we describe a patient with a homozygous p.Tyr12Cys mutation in the epsilon subunit encoded by the nuclear gene ATP5E. The 22-year-old woman presented with neonatal onset, lactic acidosis, 3-methylglutaconic aciduria, mild mental retardation and developed peripheral neuropathy. Patient fibroblasts showed 60-70% decrease in both oligomycin-sensitive ATPase activity and mitochondrial ATP synthesis. The mitochondrial content of the ATP synthase complex was equally reduced, but its size was normal and it contained the mutated epsilon subunit. A similar reduction was found in all investigated F1 and Fo subunits with the exception of Fo subunit c, which was found to accumulate in a detergent-insoluble form. This is the first case of a mitochondrial disease due to a mutation in a nuclear encoded structural subunit of the ATP synthase. Our results indicate an essential role of the epsilon subunit in the biosynthesis and assembly of the F1 part of the ATP synthase. Furthermore, the epsilon subunit seems to be involved in the incorporation of subunit c to the rotor structure of the mammalian enzyme.
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Affiliation(s)
- Johannes A Mayr
- Department of Pediatrics, Paracelsus Medical University, Salzburg A5020, Austria
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21
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Havlícková V, Kaplanová V, Nůsková H, Drahota Z, Houstek J. Knockdown of F1 epsilon subunit decreases mitochondrial content of ATP synthase and leads to accumulation of subunit c. BIOCHIMICA ET BIOPHYSICA ACTA 2010; 1797:1124-9. [PMID: 20026007 DOI: 10.1016/j.bbabio.2009.12.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2009] [Revised: 12/11/2009] [Accepted: 12/13/2009] [Indexed: 10/20/2022]
Abstract
The subunit epsilon of mitochondrial ATP synthase is the only F1 subunit without a homolog in bacteria and chloroplasts and represents the least characterized F1 subunit of the mammalian enzyme. Silencing of the ATP5E gene in HEK293 cells resulted in downregulation of the activity and content of the mitochondrial ATP synthase complex and of ADP-stimulated respiration to approximately 40% of the control. The decreased content of the epsilon subunit was paralleled by a decrease in the F1 subunits alpha and beta and in the Fo subunits a and d while the content of the subunit c was not affected. The subunit c was present in the full-size ATP synthase complex and in subcomplexes of 200-400 kDa that neither contained the F1 subunits, nor the Fo subunits. The results indicate that the epsilon subunit is essential for the assembly of F1 and plays an important role in the incorporation of the hydrophobic subunit c into the F1-c oligomer rotor of the mitochondrial ATP synthase complex.
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Affiliation(s)
- Vendula Havlícková
- Department of Bioenergetics, Institute of Physiology and Centre for Applied Genomics, Academy of Sciences of the Czech Republic, 142 20 Prague
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22
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Gómez LA, Monette JS, Chavez JD, Maier CS, Hagen TM. Supercomplexes of the mitochondrial electron transport chain decline in the aging rat heart. Arch Biochem Biophys 2009; 490:30-5. [PMID: 19679098 DOI: 10.1016/j.abb.2009.08.002] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2009] [Revised: 08/03/2009] [Accepted: 08/04/2009] [Indexed: 01/06/2023]
Abstract
Accumulation of mitochondrial electron transport chain (ETC) defects is a recognized hallmark of the age-associated decline in cardiac bioenergetics; however, the molecular events involved are only poorly understood. In the present work, we hypothesized that age-related ETC deterioration stemmed partly from disassociation of large solid-state macromolecular assemblies termed "supercomplexes". Mitochondrial proteins from young and old rat hearts were separated by blue native-PAGE, protein bands analyzed by LC-MALDI-MS/MS, and protein levels quantified by densitometry. Results showed that supercomplexes comprised of various stoichiometries of complexes I, III and IV were observed, and declined significantly (p<0.05, n=4) with age. Supercomplexes displaying the highest molecular masses were the most severely affected. Considering that certain diseases (e.g. Barth Syndrome) display similar supercomplex destabilization as our results for aging, the deterioration in ETC supercomplexes may be an important underlying factor for both impaired mitochondrial function and loss of cardiac bioenergetics with age.
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Affiliation(s)
- Luis A Gómez
- Linus Pauling Institute and Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331, USA
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23
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Wilmer MJ, van den Heuvel LP, Rodenburg RJ, Vogel RO, Nijtmans LG, Monnens LA, Levtchenko EN. Mitochondrial complex V expression and activity in cystinotic fibroblasts. Pediatr Res 2008; 64:495-7. [PMID: 18596576 DOI: 10.1203/pdr.0b013e318183fd67] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Alterations in ATP metabolism have been proposed to be involved in the pathogenesis of cystinosis, the most common form of inherited Fanconi syndrome. A recent study showed normal activity of respiratory chain complexes I-IV with decreased ATP levels in cystinotic fibroblasts. Here, we show normal complex V expression and activity in mitochondria of cystinotic fibroblasts. This indicates that alterations in mitochondrial oxidative phosphorylation enzymes are not responsible for ATP decrease in cystinotic fibroblasts.
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Affiliation(s)
- Martijn J Wilmer
- Laboratory of Pediatrics and Neurology, Radboud University Nijmegen Medical Centre, Nijmegen, 6500 HB, The Netherlands.
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24
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Wittig I, Schägger H. Features and applications of blue-native and clear-native electrophoresis. Proteomics 2008; 8:3974-90. [DOI: 10.1002/pmic.200800017] [Citation(s) in RCA: 136] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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25
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Janssen AJM, Schuelke M, Smeitink JAM, Trijbels FJM, Sengers RCA, Lucke B, Wintjes LTM, Morava E, van Engelen BGM, Smits BW, Hol FA, Siers MH, Ter Laak H, van der Knaap MS, Van Spronsen FJ, Rodenburg RJT, van den Heuvel LP. Muscle 3243A-->G mutation load and capacity of the mitochondrial energy-generating system. Ann Neurol 2008; 63:473-81. [PMID: 18306232 DOI: 10.1002/ana.21328] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVE The mitochondrial energy-generating system (MEGS) encompasses the mitochondrial enzymatic reactions from oxidation of pyruvate to the export of adenosine triphosphate. It is investigated in intact muscle mitochondria by measuring the pyruvate oxidation and adenosine triphosphate production rates, which we refer to as the "MEGS capacity." Currently, little is known about MEGS pathology in patients with mutations in the mitochondrial DNA. Because MEGS capacity is an indicator for the overall mitochondrial function related to energy production, we searched for a correlation between MEGS capacity and 3243A-->G mutation load in muscle of patients with the MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes) syndrome. METHODS In muscle tissue of 24 patients with the 3243A-->G mutation, we investigated the MEGS capacity, the respiratory chain enzymatic activities, and the 3243A-->G mutation load. To exclude coinciding mutations, we sequenced all 22 mitochondrial transfer RNA genes in the patients, if possible. RESULTS We found highly significant differences between patients and control subjects with respect to the MEGS capacity and complex I, III, and IV activities. MEGS-related measurements correlated considerably better with the mutation load than respiratory chain enzyme activities. We found no additional mutations in the mitochondrial transfer RNA genes of the patients. INTERPRETATION The results show that MEGS capacity has a greater sensitivity than respiratory chain enzymatic activities for detection of subtle mitochondrial dysfunction. This is important in the workup of patients with rare or new mitochondrial DNA mutations, and with low mutation loads. In these cases we suggest to determine the MEGS capacity.
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Affiliation(s)
- Antoon J M Janssen
- Department of Pediatrics and Laboratory of Pediatrics and Neurology, Nijmegen Centre for Mitochondrial Disorders, Radboud University Medical Centre, Nijmegen, The Netherlands
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26
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Wijnhoven HJH, Ennen L, Rodenburg RJT, Dekhuijzen PNR. Mitochondrial function in diaphragm of emphysematous hamsters after treatment with nandrolone. Int J Chron Obstruct Pulmon Dis 2007; 1:83-9. [PMID: 18046906 PMCID: PMC2706598 DOI: 10.2147/copd.2006.1.1.83] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Respiratory failure in patients with COPD may be caused by insufficient force production or insufficient endurance capacity of the respiratory muscles. Anabolic steroids may improve respiratory muscle function in COPD. The effect of anabolic steroids on mitochondrial function in the diaphragm in emphysema is unknown. In an emphysematous male hamster model, we investigated whether administration of the anabolic steroid nandrolone decanoate (ND) altered the activity of mitochondrial respiratory chain complexes in the diaphragm. The bodyweight of hamsters treated with ND was decreased after treatment compared with initial values, and serum testosterone levels were significantly lower in hamsters treated with ND than in control hamsters. No difference in the activity of mitochondrial respiratory chain complexes in the diaphragm between normal and emphysematous hamsters was observed. Treatment with ND did not change the activity of mitochondrial respiratory chain complexes in the diaphragm of both normal and emphysematous hamsters. In emphysematous hamsters, administration of ND decreased the activity of succinate:cytochrome c oxidoreductase compared with ND treatment in normal hamsters. We conclude that anabolic steroids have negative effects on the activity of succinate:cytochrome c oxidoreductase and anabolic status in this emphysematous hamster model.
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Affiliation(s)
- Hanneke J H Wijnhoven
- Department of Pulmonary Diseases, Institute for Fundamental and Clinical Human Movement Sciences, Radboud University, Nijmegen Medical Centre, Nijmegen, The Netherlands
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27
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Ruiter EM, Siers MH, van den Elzen C, van Engelen BG, Smeitink JAM, Rodenburg RJ, Hol FA. The mitochondrial 13513G > A mutation is most frequent in Leigh syndrome combined with reduced complex I activity, optic atrophy and/or Wolff-Parkinson-White. Eur J Hum Genet 2006; 15:155-61. [PMID: 17106447 DOI: 10.1038/sj.ejhg.5201735] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The m.13513G > A transition in the mitochondrial gene encoding the ND5 subunit of respiratory chain complex I, can cause mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS) and has been reported to be a frequent cause of Leigh syndrome (LS). We determined the frequency of the mutation in a cohort of 123 patients with reduced complex I activity in muscle (n = 113) or fibroblast (n = 10) tissue. We describe a Pyrosequencing assay for rapid detection and quantification of the m.13513G > A mutation. Two patients with the mutation were identified; both had LS, optical atrophy and a Wolff-Parkinson-White Syndrome (WPWS)-like cardiac conduction defect. The clinical presentation of the m.13513G > A mutation is discussed. We conclude that the m.13513G > A mutation seems not as frequent as previously suggested and is most likely to be present in patients with Leigh (-like) syndrome combined with a complex I deficiency, optic atrophy and/ or WPWS. In addition, we confirmed that the adjacent m.13514A > G mutation is a rare cause of LS or MELAS since no cases with this transition were found.
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Affiliation(s)
- E Mariken Ruiter
- Radboud University Nijmegen Medical Centre, Department of Human Genetics, Nijmegen, The Netherlands.
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28
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Coenen MJH, Smeitink JAM, Pots JM, van Kaauwen E, Trijbels FJM, Hol FA, van den Heuvel LP. Sequence analysis of the structural nuclear encoded subunits and assembly genes of cytochrome c oxidase in a cohort of 10 isolated complex IV-deficient patients revealed five mutations. J Child Neurol 2006; 21:508-11. [PMID: 16948936 DOI: 10.1177/08830738060210062501] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The mitochondrial oxidative phosphorylation system is composed of five multiprotein complexes. The fourth complex of this system, cytochrome c oxidase (complex IV), consists of 13 subunits: 3 encoded by mitochondrial DNA and 10 encoded by the nuclear genome. Patients with an isolated complex IV deficiency frequently harbor mutations in nuclear genes encoding for proteins necessary for the assembly of the complex. Strikingly, until now, no mutations have been detected in the nuclear encoded structural subunits of complex IV in these patients. We report the results of a mutational analysis study in patients with isolated complex IV deficiency screened for mutations in all structural genes as well as assembly genes known to cause complex IV deficiency. Four patients carried mutations in the complex IV assembly gene SURF1. One patient harbored a mutation in the COX10 gene involved in heme A synthesis. Mutations in the 10 nuclear encoded structural genes were not present.
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Affiliation(s)
- Marieke J H Coenen
- Department of Paediatrics, Nijmegen Centre for Mitochondrial Disorders, Radboud University Nijmegen Medical Centre, 6500 HB Nijmegen, the Netherlands
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29
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Morava E, Rodenburg R, Hol F, De Meirleir L, Seneca S, Busch R, van den Heuvel L, Smeitink J. Mitochondrial dysfunction in Brooks-Wisniewski-Brown syndrome. Am J Med Genet A 2006; 140:752-6. [PMID: 16477654 DOI: 10.1002/ajmg.a.31117] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Brooks, Wisniewski, and Brown described a familial presentation of severe developmental retardation, speech delay, static encephalopathy with atrophic hydrocephalus, microcephaly, progressive spastic diplegia, a characteristic facial appearance, optic atrophy, and growth retardation associated with hypoplastic corpus callosum in one of the patients. The authors postulated a distinct X-linked mental retardation syndrome. Later on a similar phenotype was observed in three male siblings with an early lethal outcome. Here we describe three patients with several overlapping features and a progressive neurological picture presenting with a significantly compromised mitochondrial oxidative phosphorylation measured in a fresh muscle biopsy. Neurological deterioration is a commonly observed feature in mitochondrial disorders. Based on the unique combination of the clinical symptoms, we suggest that our patients have the Brooks-Wisniewski-Brown syndrome.
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Affiliation(s)
- Eva Morava
- Department of Pediatrics, Radboud University Nijmegen Medical Centre, Nijmegen Centre for Mitochondrial Disorders, Nijmegen, The Netherlands.
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30
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Levtchenko EN, Wilmer MJG, Janssen AJM, Koenderink JB, Visch HJ, Willems PHGM, de Graaf-Hess A, Blom HJ, van den Heuvel LP, Monnens LA. Decreased intracellular ATP content and intact mitochondrial energy generating capacity in human cystinotic fibroblasts. Pediatr Res 2006; 59:287-92. [PMID: 16439594 DOI: 10.1203/01.pdr.0000196334.46940.54] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Cystinosis is an autosomal recessive lysosomal storage disorder caused by a defect in the lysosomal cystine carrier cystinosin. Cystinosis is the most common cause of inherited Fanconi syndrome leading to renal failure, in which the pathogenesis is still enigmatic. Based on studies of proximal tubules loaded with cystine dimethyl ester (CDME), altered mitochondrial adenosine triphosphate (ATP) production was proposed to be an underlying pathologic mechanism. Thus far, however, experimental evidence supporting this hypothesis in humans is lacking. In this study, energy metabolism was extensively investigated in primary fibroblasts derived from eight healthy subjects and eight patients with cystinosis. Patient's fibroblasts accumulated marked amounts of cystine and displayed a significant decrease in intracellular ATP content. Remarkably, overall energy-generating capacity, activity of respiratory chain complexes, ouabain-dependent rubidium uptake reflecting Na,K-ATPase activity, and bradykinin-stimulated mitochondrial ATP production were all normal in these cells. In conclusion, the data presented demonstrate that mitochondrial energy-generating capacity and Na,K-ATPase activity are intact in cultured cystinotic fibroblasts, thus questioning the idea of altered mitochondrial ATP synthesis as a keystone for the pathogenesis of cystinosis.
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Affiliation(s)
- Elena N Levtchenko
- Department of Pediatrics, Radboud University Nijmegen Medical Center, The Netherlands.
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31
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Wijnhoven JH, Janssen AJM, van Kuppevelt TH, Rodenburg RJT, Dekhuijzen PNR. Metabolic capacity of the diaphragm in patients with COPD. Respir Med 2005; 100:1064-71. [PMID: 16257195 DOI: 10.1016/j.rmed.2005.09.029] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2005] [Revised: 09/23/2005] [Accepted: 09/26/2005] [Indexed: 11/26/2022]
Abstract
Chronic obstructive pulmonary disease (COPD) is associated with an increased load on the diaphragm. Chronic loading on skeletal muscles results in metabolic changes and fiber-type shifts. Therefore, we investigated whether the load on the human diaphragm imposed by COPD altered oxidative enzyme activity, glycogenolytic enzyme activity and mitochondrial energy generating capacity and efficiency. Biopsies of the diaphragm from COPD patients and control subjects were obtained and activities of L(+)3-hydroxyacylCoA-dehydrogenase (HADH, marker for beta-oxidation capacity) and phosphorylase (marker for glycogenolytic capacity) were measured spectrophotometrically. Mitochondrial energy generating capacity was measured by spectrophotometrical and radiochemical methods. Fiber-type distribution was determined electrophoretically. We found that HADH activity was increased with increasing severity of COPD (P=0.05). No change in glycogenolytic enzyme activity was observed. The activity of the mitochondrial respiratory chain complexes III and IV and oxidation of pyruvate was increased with increasing airflow obstruction. These results suggest that in COPD the diaphragm adapts to a higher workload by increasing the oxidative capacity and mitochondrial function.
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Affiliation(s)
- J H Wijnhoven
- Department of Pulmonary Diseases and Institute for Fundamental and Clinical Human Movement Sciences, Radboud University Nijmegen Medical Centre, PO Box 9101, 6500 HB Nijmegen, The Netherlands
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32
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Ješina P, Tesařová M, Fornůsková D, Vojtíšková A, Pecina P, Kaplanová V, Hansíková H, Zeman J, Houštěk J. Diminished synthesis of subunit a (ATP6) and altered function of ATP synthase and cytochrome c oxidase due to the mtDNA 2 bp microdeletion of TA at positions 9205 and 9206. Biochem J 2005; 383:561-71. [PMID: 15265003 PMCID: PMC1133750 DOI: 10.1042/bj20040407] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Dysfunction of mitochondrial ATPase (F1F(o)-ATP synthase) due to missense mutations in ATP6 [mtDNA (mitochondrial DNA)-encoded subunit a] is a frequent cause of severe mitochondrial encephalomyopathies. We have investigated a rare mtDNA mutation, i.e. a 2 bp deletion of TA at positions 9205 and 9206 (9205DeltaTA), which affects the STOP codon of the ATP6 gene and the cleavage site between the RNAs for ATP6 and COX3 (cytochrome c oxidase 3). The mutation was present at increasing load in a three-generation family (in blood: 16%/82%/>98%). In the affected boy with severe encephalopathy, a homoplasmic mutation was present in blood, fibroblasts and muscle. The fibroblasts from the patient showed normal aurovertin-sensitive ATPase hydrolytic activity, a 70% decrease in ATP synthesis and an 85% decrease in COX activity. ADP-stimulated respiration and the ADP-induced decrease in the mitochondrial membrane potential at state 4 were decreased by 50%. The content of subunit a was decreased 10-fold compared with other ATPase subunits, and [35S]-methionine labelling showed a 9-fold decrease in subunit a biosynthesis. The content of COX subunits 1, 4 and 6c was decreased by 30-60%. Northern Blot and quantitative real-time reverse transcription-PCR analysis further demonstrated that the primary ATP6--COX3 transcript is cleaved to the ATP6 and COX3 mRNAs 2-3-fold less efficiently. Structural studies by Blue-Native and two-dimensional electrophoresis revealed an altered pattern of COX assembly and instability of the ATPase complex, which dissociated into subcomplexes. The results indicate that the 9205DeltaTA mutation prevents the synthesis of ATPase subunit a, and causes the formation of incomplete ATPase complexes that are capable of ATP hydrolysis but not ATP synthesis. The mutation also affects the biogenesis of COX, which is present in a decreased amount in cells from affected individuals.
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Affiliation(s)
- Pavel Ješina
- *Department of Bioenergetics, Institute of Physiology and Centre for Integrated Genomics, Academy of Sciences of the Czech Republic, Vídeňská 1083, 142 20 Prague, Czech Republic
| | - Markéta Tesařová
- †Department of Pediatrics and Institute for Inherited Metabolic Disorders, 1st Faculty of Medicine, Charles University, 120 00 Prague, Czech Republic
| | - Daniela Fornůsková
- †Department of Pediatrics and Institute for Inherited Metabolic Disorders, 1st Faculty of Medicine, Charles University, 120 00 Prague, Czech Republic
| | - Alena Vojtíšková
- *Department of Bioenergetics, Institute of Physiology and Centre for Integrated Genomics, Academy of Sciences of the Czech Republic, Vídeňská 1083, 142 20 Prague, Czech Republic
| | - Petr Pecina
- *Department of Bioenergetics, Institute of Physiology and Centre for Integrated Genomics, Academy of Sciences of the Czech Republic, Vídeňská 1083, 142 20 Prague, Czech Republic
| | - Vilma Kaplanová
- *Department of Bioenergetics, Institute of Physiology and Centre for Integrated Genomics, Academy of Sciences of the Czech Republic, Vídeňská 1083, 142 20 Prague, Czech Republic
| | - Hana Hansíková
- †Department of Pediatrics and Institute for Inherited Metabolic Disorders, 1st Faculty of Medicine, Charles University, 120 00 Prague, Czech Republic
| | - Jiří Zeman
- †Department of Pediatrics and Institute for Inherited Metabolic Disorders, 1st Faculty of Medicine, Charles University, 120 00 Prague, Czech Republic
| | - Josef Houštěk
- *Department of Bioenergetics, Institute of Physiology and Centre for Integrated Genomics, Academy of Sciences of the Czech Republic, Vídeňská 1083, 142 20 Prague, Czech Republic
- To whom correspondence should be addressed (email )
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Thorburn DR, Sugiana C, Salemi R, Kirby DM, Worgan L, Ohtake A, Ryan MT. Biochemical and molecular diagnosis of mitochondrial respiratory chain disorders. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2005; 1659:121-8. [PMID: 15576043 DOI: 10.1016/j.bbabio.2004.08.006] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2004] [Revised: 08/16/2004] [Accepted: 08/16/2004] [Indexed: 12/25/2022]
Abstract
Biochemical diagnosis of mitochondrial respiratory chain disorders requires caution to avoid misdiagnosis of secondary enzyme defects, and can be improved by the use of conservative diagnostic criteria. Pathogenic mutations causing mitochondrial disorders have now been identified in more than 30 mitochondrial DNA (mtDNA) genes encoding respiratory chain subunits, ribosomal- and t-RNAs. mtDNA mutations appear to be responsible for most adult patients with mitochondrial disease and approximately a quarter of paediatric patients. A family history suggesting maternal inheritance is the exception rather than the norm for children with mtDNA mutations, many of whom have de novo mutations. Prenatal diagnosis and pre-implantation genetic diagnosis can be offered to some women at risk of transmitting a mtDNA mutation, particularly those at lower recurrence risk. Mutations in more than 30 nuclear genes, including those encoding for respiratory chain subunits and assembly factors, have now been shown to cause mitochondrial disorders, creating difficulties in prioritising which genes should be studied by mutation analysis in individual patients. A number of approaches offer promise to guide the choice of candidate genes, including Blue Native-PAGE immunoblotting and microarray expression analysis.
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Affiliation(s)
- David R Thorburn
- Murdoch Children's Research Institute, Royal Children's Hospital, Melbourne, Victoria 3052 Australia.
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34
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Coenen MJH, Smeitink JAM, Smeets R, Trijbels FJM, van den Heuvel LP. Mutation detection in four candidate genes (OXA1L, MRS2L, YME1L and MIPEP) for combined deficiencies in the oxidative phosphorylation system. J Inherit Metab Dis 2005; 28:1091-7. [PMID: 16435202 DOI: 10.1007/s10545-005-4483-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2005] [Accepted: 11/08/2005] [Indexed: 10/25/2022]
Abstract
Mitochondria are the main energy-producing organelles of the cell. Five complexes embedded in the mitochondrial inner membrane, together constituting the oxidative phosphorylation (OXPHOS) system, comprise the final steps in cellular energy production. Many patients with a mitochondrial defect suffer from a so-called combined deficiency, meaning that the enzymatic activities of two or more complexes of the OXPHOS system are decreased. Numerous mutations have been described in nuclear genes that are involved in the functioning of a single complex of the OXPHOS system. However, little attention has been paid to patients with a deficiency of more than one complex of this particular system. In this study we have investigated four nuclear genes (OXA1L, MRS2L, YME1L and MIPEP) that might be involved in the pathology of combined enzymatic deficiencies of the OXPHOS system. Based on the results of yeast knockouts of these four proteins, we have sequenced the open reading frame of OXA1L in eight patients with an enzymatic deficiency of complexes I and IV. MRS2L, YME1L and MIPEP have been sequenced in three patients with a combined defect of complexes III and IV. No mutations were detected in these patients, showing that at least in these patients the OXPHOS system deficiency cannot be explained by a mutation in these four genes.
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Affiliation(s)
- M J H Coenen
- Nijmegen Centre for Mitochondrial Disorders, Department of Paediatrics, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
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35
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Mayr JA, Paul J, Pecina P, Kurnik P, Förster H, Fötschl U, Sperl W, Houstek J. Reduced respiratory control with ADP and changed pattern of respiratory chain enzymes as a result of selective deficiency of the mitochondrial ATP synthase. Pediatr Res 2004; 55:988-94. [PMID: 15155867 DOI: 10.1203/01.pdr.0000127016.67809.6b] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The F(o)F(1)-ATPase, a multisubunit protein complex of the inner mitochondrial membrane, produces most of the ATP in mammalian cells. Mitochondrial diseases as a result of a dysfunction of ATPase can be caused by mutations in mitochondrial DNA-encoded ATPase subunit a or rarely by an ATPase defect of nuclear origin. Here we present a detailed functional and immunochemical analysis of a new case of selective and generalized ATPase deficiency found in an Austrian patient. The defect manifested with developmental delay, muscle hypotonia, failure to thrive, ptosis, and varying lactic acidemia (up to 12 mmol/L) beginning from the neonatal period. A low-degree dilated cardiomyopathy of the left ventricle developed between the age of 1 and 2 y. A >90% decrease in oligomycin-sensitive ATPase activity and an 86% decrease in the content of the ATPase complex was found in muscle mitochondria. It was associated with a significant decrease of ADP-stimulated respiration of succinate (1.5-fold) and respiratory control with ADP (1.7-fold) in permeabilized muscle fibers, and with a slight decrease of the respiratory chain complex I and compensatory increase in the content of complexes III and IV. The same ATPase deficiency without an increase in respiratory chain complexes was found in fibroblasts, suggesting a generalized defect with tissue-specific manifestation. Absence of any mutations in mitochondrial ATP6 and ATP8 genes indicates a nuclear origin of the defect.
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Affiliation(s)
- Johannes A Mayr
- Department of Pediatrics, General Hospital Salzburg, Austria
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36
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Dubot A, Godinot C, Dumur V, Sablonnière B, Stojkovic T, Cuisset JM, Vojtiskova A, Pecina P, Jesina P, Houstek J. GUG is an efficient initiation codon to translate the human mitochondrial ATP6 gene. Biochem Biophys Res Commun 2004; 313:687-93. [PMID: 14697245 DOI: 10.1016/j.bbrc.2003.12.013] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
A maternally inherited and practically homoplasmic mitochondrial (mtDNA) mutation, 8527A>G, changing the initiation codon AUG into GUG, normally coding for a valine, was observed in the ATP6 gene encoding the ATPase subunit a. No alternate Met codon could replace the normal translational initiator. The patient harboring this mutation exhibited clinical symptoms suggesting a mitochondrial disease but his mother who carried the same mtDNA mutation was healthy. The mutation was absent from 100 controls and occurred once amongst 44 patients suspected of Leber Hereditary Optic Neuropathy (LHON) but devoid of typical LHON mutations. In patient fibroblasts, no effect of 8527A>G mutation could be demonstrated on the biosynthesis of mtDNA-encoded proteins, on size and the content of ATPase subunit a, on ATP hydrolysis and on mitochondrial membrane potential. In addition, ATP synthesis was barely decreased. Therefore, GUG is a functional initiation codon for the human ATP6 gene.
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Affiliation(s)
- A Dubot
- Centre National de la Recherche Scientifique, Université Claude Bernard de Lyon I, 69622 Villeurbanne France
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37
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Niers L, van den Heuvel L, Trijbels F, Sengers R, Smeitink J. Prerequisites and strategies for prenatal diagnosis of respiratory chain deficiency in chorionic villi. J Inherit Metab Dis 2003; 26:647-58. [PMID: 14707513 DOI: 10.1023/b:boli.0000005605.57420.b4] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Prenatal diagnosis for respiratory chain deficiencies is a complex procedure that requires a thorough diagnostic work-up of the index patient. This includes confirmation of the clinical and metabolic evaluations through histological and enzymatic examinations of tissue biopsies. Prenatal diagnosis currently relies on biochemical assays of respiratory chain complexes in chorionic villi or amniocytes and is possible by mutation analysis of nuclear genes in a limited but increasing proportion of cases. Based on a recent survey of prenatal diagnosis in families with complex I and complex IV deficiencies, performed at Nijmegen Centre for Mitochondrial Disorders (NCMD), prerequisites and strategies for performing prenatal diagnosis have been developed to increase reliability. Biochemical investigations in chorionic villi can be done reliably if the respiratory chain enzyme deficiency is expressed in both skeletal muscle and skin fibroblasts to rule out tissue specificity. No mitochondrial DNA defects must be suspected or established. The NCMD does not offer prenatal diagnosis until all the prerequisites have been confirmed. We expect prenatal diagnosis at the molecular level to become more feasible in time as the mutational spectrum broadens with advances in medical research.
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Affiliation(s)
- L Niers
- Department of Paediatrics, Nijmegen Centre for Mitochondrial Disorders, The Netherlands
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38
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Grafakou O, Hol FA, Otfried Schwab K, Siers MH, ter Laak H, Trijbels F, Ensenauer R, Boelen C, Smeitink J. Exercise intolerance, muscle pain and lactic acidaemia associated with a 7497G>A mutation in the tRNASer(UCN) gene. J Inherit Metab Dis 2003; 26:593-600. [PMID: 14605505 DOI: 10.1023/a:1025960300710] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
A 13-year-old girl with non-familial exercise intolerance, muscle pain and lactic acidaemia underwent a muscle biopsy for suspected mitochondrial disease. Muscle morphology showed 25% ragged-red fibres and 80% COX-negative staining. Enzymatic activities of mitochondrially co-encoded respiratory chain enzymes (complexes I, III, and IV) were decreased in muscle but normal in cultured skin fibroblasts. mtDNA analysis revealed the presence of the 7497G>A mutation in the tRNASer(UCN) gene, homoplasmic in skeletal muscle and 90% in leukocytes. Analysis of the mother's mtDNA showed 10% heteroplasmy in blood. It may be concluded that the 7497G>A mutation is associated with a muscle-only disease presentation for which high levels of mutated mtDNA are required. Exercise intolerance and muscle pain in otherwise normal children warrants further mitochondrial evaluation.
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Affiliation(s)
- O Grafakou
- Department of Pediatrics, Nijmegen Center for Mitochondrial Disorders, University Medical Center Nijmegen, The Netherlands
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39
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Schuelke M, Detjen A, van den Heuvel L, Korenke C, Janssen A, Smits A, Trijbels F, Smeitink J. New Nuclear Encoded Mitochondrial Mutation Illustrates Pitfalls in Prenatal Diagnosis by Biochemical Methods. Clin Chem 2002. [DOI: 10.1093/clinchem/48.5.772] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- Markus Schuelke
- Department of Neuropediatrics, Charité Virchow University Hospital, Augustenburger Platz 1, D-13353 Berlin, Germany
| | - Anne Detjen
- Department of Neuropediatrics, Charité Virchow University Hospital, Augustenburger Platz 1, D-13353 Berlin, Germany
| | - Lambert van den Heuvel
- Department of Pediatrics, Nijmegen Center for Mitochondrial Disorders, University Medical Center Nijmegen, PO Box 9101, NL-6500 HB Nijmegen, The Netherlands
| | - Christoph Korenke
- Department of Neuropediatrics, Children’s Hospital, Georg-August-Universität, Robert-Koch Strasse 40, D-37075 Göttingen, Germany
| | - Antoon Janssen
- Department of Pediatrics, Nijmegen Center for Mitochondrial Disorders, University Medical Center Nijmegen, PO Box 9101, NL-6500 HB Nijmegen, The Netherlands
| | - Arie Smits
- Department of Human Genetics, University Medical Center, PO Box 9101, NL-6500 HB Nijmegen, The Netherlands
| | - Frans Trijbels
- Department of Pediatrics, Nijmegen Center for Mitochondrial Disorders, University Medical Center Nijmegen, PO Box 9101, NL-6500 HB Nijmegen, The Netherlands
| | - Jan Smeitink
- Department of Pediatrics, Nijmegen Center for Mitochondrial Disorders, University Medical Center Nijmegen, PO Box 9101, NL-6500 HB Nijmegen, The Netherlands
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40
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Schuelke M, Krude H, Finckh B, Mayatepek E, Janssen A, Schmelz M, Trefz F, Trijbels F, Smeitink J. Septo-optic dysplasia associated with a new mitochondrial cytochrome b mutation. Ann Neurol 2002; 51:388-92. [PMID: 11891837 DOI: 10.1002/ana.10151] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We report on a 25-year-old patient with isolated mitochondrial complex III deficiency and a new heteroplasmic mutation (T14849C) in the cytochrome b gene. He suffered from septo-optic dysplasia, retinitis pigmentosa, exercise intolerance, hypertrophic cardiomyopathy, and rhabdomyolysis. A HESX1 mutation was excluded as a cause of his septo-optic dysplasia. Low alpha-tocopherol concentrations in his muscles and an elevated urinary leukotriene E(4) excretion indicate increased production of reactive oxygen species.
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Affiliation(s)
- Markus Schuelke
- Department Neuropediatrics, Charité University Hospital, Berlin, Germany.
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41
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Loeffen J, Elpeleg O, Smeitink J, Smeets R, Stöckler-Ipsiroglu S, Mandel H, Sengers R, Trijbels F, van den Heuvel L. Mutations in the complex I NDUFS2 gene of patients with cardiomyopathy and encephalomyopathy. Ann Neurol 2001; 49:195-201. [PMID: 11220739 DOI: 10.1002/1531-8249(20010201)49:2<195::aid-ana39>3.0.co;2-m] [Citation(s) in RCA: 149] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Human complex I is built up and regulated by genes encoded by the mitochondrial DNA (mtDNA) as well as the nuclear DNA (nDNA). In recent years, attention mainly focused on the relation between complex I deficiency and mtDNA mutations. However, a high percentage of consanguinity and an autosomal-recessive mode of inheritance observed within our patient group as well as the absence of common mtDNA mutations make a nuclear genetic cause likely. The NDUFS2 protein is part of complex I of many pro- and eukaryotes. The nuclear gene coding for this protein is therefore an important candidate for mutational detection studies in enzymatic complex I deficient patients. Screening of patient NDUFS2 cDNA by reverse transcriptase-polymerase chain reaction (RT-PCR) in combination with direct DNA sequencing revealed three missense mutations resulting in the substitution of conserved amino acids in three families.
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Affiliation(s)
- J Loeffen
- Nijmegen Center for Mitochondrial Disorders, Department of Pediatrics, The Netherlands
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42
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Budde SM, van den Heuvel LP, Janssen AJ, Smeets RJ, Buskens CA, DeMeirleir L, Van Coster R, Baethmann M, Voit T, Trijbels JM, Smeitink JA. Combined enzymatic complex I and III deficiency associated with mutations in the nuclear encoded NDUFS4 gene. Biochem Biophys Res Commun 2000; 275:63-8. [PMID: 10944442 DOI: 10.1006/bbrc.2000.3257] [Citation(s) in RCA: 148] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Combined OXPHOS-system enzyme deficiencies are observed in approximately 25% of all OXPHOS-system disturbances. Of these, combined complex I and III deficiency is relatively scarce. So far, only mtDNA and thymidine phosphorylase (TP) mutations have been associated with combined OXPHOS-system disturbances. In this report we show, for the first time, that a nuclear gene mutation in a structural, nuclear encoded complex I gene is associated with combined complex I and III deficiency. After our initial report we describe mutations in the NDUFS4 gene of complex I in two additional patients. The first mutation is a deletion of G at position 289 or 290. Amino acid 96 changes from a tryptophan to a stop codon. The mutation was found homozygous in the patient; both parents are heterozygous for the mutation. The second mutation is a transition from C to T at cDNA position 316. Codon is changed from CGA (arginine) to TGA (stop). The patient is homozygous for the mutation; both parents are heterozygous. Both mutations in the NDUFS4 gene led to a premature stop in Leigh-like patients with an early lethal phenotype. We hypothesise that the structural integrity of the OXPHOS system, in mammal supermolecular structures, may be responsible for the observed biochemical features.
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Affiliation(s)
- S M Budde
- Nijmegen Centre for Mitochondrial Disorders, University Medical Centre Nijmegen, Nijmegen, The Netherlands
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43
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Loeffen JL, Smeitink JA, Trijbels JM, Janssen AJ, Triepels RH, Sengers RC, van den Heuvel LP. Isolated complex I deficiency in children: clinical, biochemical and genetic aspects. Hum Mutat 2000; 15:123-34. [PMID: 10649489 DOI: 10.1002/(sici)1098-1004(200002)15:2<123::aid-humu1>3.0.co;2-p] [Citation(s) in RCA: 204] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
We retrospectively examined clinical and biochemical characteristics of 27 patients with isolated enzymatic complex I deficiency (established in cultured skin fibroblasts) in whom common pathogenic mtDNA point mutations and major rearrangements were absent. Clinical phenotypes present in this group are Leigh syndrome (n = 7), Leigh-like syndrome (n = 6), fatal infantile lactic acidosis (n = 3), neonatal cardiomyopathy with lactic acidosis (n = 3), macrocephaly with progressive leukodystrophy (n = 2), and a residual group of unspecified encephalomyopathy (n = 6) subdivided into progressive (n = 4) and stable (n = 2) variants. Isolated complex I deficiency is one of the most frequently observed disturbance of the OXPHOS system. Respiratory chain enzyme assays performed in cultured fibroblasts and skeletal muscle tissue in general reveal similar results, but for complete diagnostics we recommend enzyme measurements performed in at least two different tissues to minimize the possibility of overlooking the enzymatic diagnosis. Lactate levels in blood and CSF and cerebral CT/MRI studies are highly informative, although normal findings do not exclude complex I deficiency. With the discovery of mutations in nuclear encoded complex I subunits, adequate pre- and postnatal counseling becomes available. Finally, considering information currently available, isolated complex I deficiency in children seems to be caused in the majority by mutations in nuclear DNA.
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Affiliation(s)
- J L Loeffen
- Nijmegen Center for Mitochondrial Disorders (NCMD), Department of Pediatrics, University Hospital Nijmegen, Nijmegen, The Netherlands
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44
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Coenen MJ, van den Heuvel LP, Nijtmans LG, Morava E, Marquardt I, Girschick HJ, Trijbels FJ, Grivell LA, Smeitink JA. SURFEIT-1 gene analysis and two-dimensional blue native gel electrophoresis in cytochrome c oxidase deficiency. Biochem Biophys Res Commun 1999; 265:339-44. [PMID: 10558868 DOI: 10.1006/bbrc.1999.1662] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Leigh syndrome, a progressive, often fatal, neurodegenerative disorder, is frequently associated with a deficiency in the activity of cytochrome c oxidase (COX), the last enzyme of the mitochondrial respiratory chain. In contrast to NADH:ubiquinone oxidoreductase and succinate dehydrogenase deficiencies, no mutations in nuclear genes encoding COX subunits have been identified thus far. Very recently, however, a Leigh syndrome complementation group has been identified which showed mutations in the SURFEIT-1 (SURF-1) gene. The results of a mutational detection study in 16 new randomly selected COX-deficient patients revealed a new mutation (C688T) in 2 patients and the earlier reported 845delCT mutation in 2 additional patients. In addition, we evaluated the diagnostic value of two-dimensional blue native gel electrophoresis. We show that this technique reveals distinct patterns of both fully and partially assembled COX complexes and is thereby capable of discrimination between COX-deficient SURF-1 and non-SURF-1-mutated patients.
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Affiliation(s)
- M J Coenen
- Department of Paediatrics, Nijmegen Centre for Mitochondrial Disorders, University Hospital St. Radboud, Nijmegen, 6500 HB, The Netherlands
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Procaccio V, Mousson B, Beugnot R, Duborjal H, Feillet F, Putet G, Pignot-Paintrand I, Lombès A, De Coo R, Smeets H, Lunardi J, Issartel JP. Nuclear DNA origin of mitochondrial complex I deficiency in fatal infantile lactic acidosis evidenced by transnuclear complementation of cultured fibroblasts. J Clin Invest 1999; 104:83-92. [PMID: 10393702 PMCID: PMC408404 DOI: 10.1172/jci6184] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
We have studied complex I (NADH-ubiquinone reductase) defects of the mitochondrial respiratory chain in 2 infants who died in the neonatal period from 2 different neurological forms of severe neonatal lactic acidosis. Specific and marked decrease in complex I activity was documented in muscle, liver, and cultured skin fibroblasts. Biochemical characterization and study of the genetic origin of this defect were performed using cultured fibroblasts. Immunodetection of 6 nuclear DNA-encoded (20, 23, 24, 30, 49, and 51 kDa) and 1 mitochondrial DNA-encoded (ND1) complex I subunits in fibroblast mitochondria revealed 2 distinct patterns. In 1 patient, complex I contained reduced amounts of the 24- and 51-kDa subunits and normal amounts of all the other investigated subunits. In the second patient, amounts of all the investigated subunits were severely decreased. The data suggest partial or extensive impairment of complex I assembly in both patients. Cell fusion experiments between 143B206 rho degrees cells, fully depleted of mitochondrial DNA, and fibroblasts from both patients led to phenotypic complementation of the complex I defects in mitochondria of the resulting cybrid cells. These results indicate that the complex I defects in the 2 reported cases are due to nuclear gene mutations.
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Affiliation(s)
- V Procaccio
- Laboratoire de Bioénergétique Cellulaire et Pathologique, EA2411 UJF/LRA6V CEA, DBMS, CEA Grenoble, 38054 Grenoble, France
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Triepels RH, van den Heuvel LP, Loeffen JL, Buskens CA, Smeets RJ, Rubio Gozalbo ME, Budde SM, Mariman EC, Wijburg FA, Barth PG, Trijbels JM, Smeitink JA. Leigh syndrome associated with a mutation in the NDUFS7 (PSST) nuclear encoded subunit of complex I. Ann Neurol 1999; 45:787-90. [PMID: 10360771 DOI: 10.1002/1531-8249(199906)45:6<787::aid-ana13>3.0.co;2-6] [Citation(s) in RCA: 136] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Leigh syndrome is the phenotypical expression of a genetically heterogeneous cluster of disorders, with pyruvate dehydrogenase complex deficiency and respiratory chain disorders as the main biochemical causes. We report the first missense mutation within the nuclear encoded complex I subunit, NDUFS7, in 2 siblings with neuropathologically proven complex I-deficient Leigh syndrome.
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Affiliation(s)
- R H Triepels
- Nijmegen Center for Mitochondrial Disorders, Department of Pediatrics, University Children's Hospital, The Netherlands
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Triepels R, Smeitink J, Loeffen J, Smeets R, Buskens C, Trijbels F, van den Heuvel L. The human nuclear-encoded acyl carrier subunit (NDUFAB1) of the mitochondrial complex I in human pathology. J Inherit Metab Dis 1999; 22:163-73. [PMID: 10234612 DOI: 10.1023/a:1005402020569] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
We present the cDNA sequence of the human mitochondrial acyl carrier protein NDUFAB1, a nuclear-encoded subunit of complex I of the mitochondrial respiratory chain. We obtained the NDUFAB1 cDNA using the cDNA sequence of the bovine mitochondrial acyl carrier protein. The human cDNA contains two putative translation initiation codons. The human NDUFAB1 protein contains a phosphopantetheine attachment site (DLGLDSLDQVEIIMAM), unique for acyl carrier proteins, and an EF-hand calcium binding domain (DIDAEKLMCPQEI). Transcripts of this gene are found in a wide range of human tissues. The highests expression levels were observed, in descending order, in adult heart, skeletal muscle and fetal heart. We subjected NDUFAB1 fibroblast cDNA of 20 patients with an isolated enzymatic complex I deficiency to mutational detection. No mutations in the NDUFAB1 open reading frame were observed. Future studies will answer whether mutations in the NDUFAB1 promoter or transcription elements are responsible for the observed complex I deficiency.
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Affiliation(s)
- R Triepels
- Nijmegen Center for Mitochondrial Disorders, University Children's Hospital, Department of Pediatrics, The Netherlands
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Loeffen J, Smeets R, Smeitink J, Triepels R, Sengers R, Trijbels F, van den Heuvel L. The human NADH: ubiquinone oxidoreductase NDUFS5 (15 kDa) subunit: cDNA cloning, chromosomal localization, tissue distribution and the absence of mutations in isolated complex I-deficient patients. J Inherit Metab Dis 1999; 22:19-28. [PMID: 10070614 DOI: 10.1023/a:1005434912463] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
We have cloned the cDNA of the NDUFS5 subunit (15 kDa) of the human mitochondrial respiratory chain complex NADH: ubiquinone oxidoreductase (complex I). The open reading frame consists of 321 base-pairs, coding for 106 amino acids, with a calculated molecular mass of 12.5 kDa. There is an 81.0% identity with the bovine equivalent on cDNA level and 74.5% identity on amino acid basis. PCR analysis of rodent-human somatic cell hybrids revealed that the human NDUFS5 gene maps to chromosome 1. The NDUFS5 mRNA is expressed ubiquitously in human tissues, with a relative higher expression in human heart, skeletal muscle, liver, kidney and fetal heart. A mutation detection study of twenty isolated enzymatic complex I-deficient patients revealed no mutations, nor polymorphisms.
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Affiliation(s)
- J Loeffen
- Nijmegen Center for Mitochondrial Disorders, University Children's Hospital, The Netherlands
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49
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Loeffen J, Smeitink J, Triepels R, Smeets R, Schuelke M, Sengers R, Trijbels F, Hamel B, Mullaart R, van den Heuvel L. The first nuclear-encoded complex I mutation in a patient with Leigh syndrome. Am J Hum Genet 1998; 63:1598-608. [PMID: 9837812 PMCID: PMC1377631 DOI: 10.1086/302154] [Citation(s) in RCA: 194] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Nicotinamide adenine dinucleotide (NADH):ubiquinone oxidoreductase (complex I) is the largest multiprotein enzyme complex of the respiratory chain. The nuclear-encoded NDUFS8 (TYKY) subunit of complex I is highly conserved among eukaryotes and prokaryotes and contains two 4Fe4S ferredoxin consensus patterns, which have long been thought to provide the binding site for the iron-sulfur cluster N-2. The NDUFS8 cDNA contains an open reading frame of 633 bp, coding for 210 amino acids. Cycle sequencing of amplified NDUFS8 cDNA of 20 patients with isolated enzymatic complex I deficiency revealed two compound heterozygous transitions in a patient with neuropathologically proven Leigh syndrome. The first mutation was a C236T (P79L), and the second mutation was a G305A (R102H). Both mutations were absent in 70 control alleles and cosegregated within the family. A progressive clinical phenotype proceeding to death in the first months of life was expressed in the patient. In the 19 other patients with enzymatic complex I deficiency, no mutations were found in the NDUFS8 cDNA. This article describes the first molecular genetic link between a nuclear-encoded subunit of complex I and Leigh syndrome.
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Affiliation(s)
- J Loeffen
- Department of Pediatrics, Nijmegen Center for Mitochondrial Disorders, The Netherlands
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Loeffen J, Smeets R, Smeitink J, Ruitenbeek W, Janssen A, Mariman E, Sengers R, Trijbels F, van den Heuvel L. The X-chromosomal NDUFA1 gene of complex I in mitochondrial encephalomyopathies: tissue expression and mutation detection. J Inherit Metab Dis 1998; 21:210-5. [PMID: 9686359 DOI: 10.1023/a:1005339332062] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- J Loeffen
- University Hospital Nijmegen, Department of Paediatrics, The Netherlands
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