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Yazdani M. Cellular and Molecular Responses to Mitochondrial DNA Deletions in Kearns-Sayre Syndrome: Some Underlying Mechanisms. Mol Neurobiol 2024; 61:5665-5679. [PMID: 38224444 DOI: 10.1007/s12035-024-03938-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2024]
Abstract
Kearns-Sayre syndrome (KSS) is a rare multisystem mitochondrial disorder. It is caused by mitochondrial DNA (mtDNA) rearrangements, mostly large-scale deletions of 1.1-10 kb. These deletions primarily affect energy supply through impaired oxidative phosphorylation and reduced ATP production. This impairment gives rise to dysfunction of several tissues, in particular those with high energy demand like brain and muscles. Over the past decades, changes in respiratory chain complexes and energy metabolism have been emphasized, whereas little attention has been paid to other reports on ROS overproduction, protein synthesis inhibition, myelin vacuolation, demyelination, autophagy, apoptosis, and involvement of lipid raft and oligodendrocytes in KSS. Therefore, this paper draws attention towards these relatively underemphasized findings that might further clarify the pathologic cascades following deletions in the mtDNA.
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Affiliation(s)
- Mazyar Yazdani
- Department of Medical Biochemistry, Oslo University Hospital, Rikshospitalet, Oslo, 0027, Norway.
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2
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Kawalec M, Wojtyniak P, Bielska E, Lewczuk A, Boratyńska-Jasińska A, Beręsewicz-Haller M, Frontczak-Baniewicz M, Gewartowska M, Zabłocka B. Mitochondrial dynamics, elimination and biogenesis during post-ischemic recovery in ischemia-resistant and ischemia-vulnerable gerbil hippocampal regions. Biochim Biophys Acta Mol Basis Dis 2023; 1869:166633. [PMID: 36566873 DOI: 10.1016/j.bbadis.2022.166633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 12/14/2022] [Accepted: 12/16/2022] [Indexed: 12/24/2022]
Abstract
Transient ischemic attacks (TIA) result from a temporary blockage in blood circulation in the brain. As TIAs cause disabilities and often precede full-scale strokes, the effects of TIA are investigated to develop neuroprotective therapies. We analyzed changes in mitochondrial network dynamics, mitophagy and biogenesis in sections of gerbil hippocampus characterized by a different neuronal survival rate after 5-minute ischemia-reperfusion (I/R) insult. Our research revealed a significantly greater mtDNA/nDNA ratio in CA2-3, DG hippocampal regions (5.8 ± 1.4 vs 3.6 ± 0.8 in CA1) that corresponded to a neuronal resistance to I/R. During reperfusion, an increase of pro-fission (phospho-Ser616-Drp1/Drp1) and pro-fusion proteins (1.6 ± 0.5 and 1.4 ± 0.3 for Mfn2 and Opa1, respectively) was observed in CA2-3, DG. Selective autophagy markers, PINK1 and SQSTM1/p62, were elevated 24-96 h after I/R and accompanied by significant elevation of transcription factors proteins PGC-1α and Nrf1 (1.2 ± 0.4, 1.78 ± 0.6, respectively) and increased respiratory chain proteins (e.g., 1.5 ± 0.3 for complex IV at I/R 96 h). Contrastingly, decreased enzymatic activity of citrate synthase, reduced Hsp60 protein level and electron transport chain subunits (0.88 ± 0.03, 0.74 ± 0.1 and 0.71 ± 0.1 for complex IV at I/R 96 h, respectively) were observed in I/R-vulnerable CA1. The phospho-Ser616-Drp1/Drp1 was increased while Mfn2 and total Opa1 reduced to 0.88 ± 0.1 and 0.77 ± 0.17, respectively. General autophagy, measured as LC3-II/I ratio, was activated 3 h after reperfusion reaching 2.37 ± 0.9 of control. This study demonstrated that enhanced mitochondrial fusion, followed by late and selective mitophagy and mitochondrial biogenesis might together contribute to reduced susceptibility to TIA.
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Affiliation(s)
- Maria Kawalec
- Molecular Biology Unit, Mossakowski Medical Research Institute, Polish Academy of Sciences, Warsaw, Poland.
| | - Piotr Wojtyniak
- Molecular Biology Unit, Mossakowski Medical Research Institute, Polish Academy of Sciences, Warsaw, Poland
| | - Ewelina Bielska
- Molecular Biology Unit, Mossakowski Medical Research Institute, Polish Academy of Sciences, Warsaw, Poland
| | - Anita Lewczuk
- Molecular Biology Unit, Mossakowski Medical Research Institute, Polish Academy of Sciences, Warsaw, Poland
| | - Anna Boratyńska-Jasińska
- Molecular Biology Unit, Mossakowski Medical Research Institute, Polish Academy of Sciences, Warsaw, Poland
| | | | | | - Magdalena Gewartowska
- Electron Microscopy Research Unit, Mossakowski Medical Research Institute, Polish Academy of Sciences, Warsaw, Poland
| | - Barbara Zabłocka
- Molecular Biology Unit, Mossakowski Medical Research Institute, Polish Academy of Sciences, Warsaw, Poland
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Noor RAM, Shah NSM, Zin AAM, Sulaiman WAW, Halim AS. Disoriented Collagen Fibers and Disorganized, Fibrotic Orbicularis Oris Muscle Fiber with Mitochondrial Myopathy in Non-Syndromic Cleft Lip. Arch Oral Biol 2022; 140:105448. [DOI: 10.1016/j.archoralbio.2022.105448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 04/25/2022] [Accepted: 04/26/2022] [Indexed: 11/02/2022]
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Machiraju P, Degtiarev V, Patel D, Hazari H, Lowry RB, Bedard T, Sinasac D, Brundler MA, Greenway SC, Khan A. Phenotype and pathology of the dilated cardiomyopathy with ataxia syndrome in children. J Inherit Metab Dis 2022; 45:366-376. [PMID: 34580891 DOI: 10.1002/jimd.12441] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 09/26/2021] [Accepted: 09/27/2021] [Indexed: 11/06/2022]
Abstract
The dilated cardiomyopathy with ataxia syndrome (DCMA) is an autosomal recessive mitochondrial disease caused by mutations in the DnaJ heat shock protein family (Hsp40) member C19 (DNAJC19) gene. DCMA or 3-methylglutaconic aciduria type V is globally rare, but the largest number of patients in the world is found in the Hutterite population of southern Alberta in Canada. We provide an update on phenotypic findings, natural history, pathological findings, and our clinical experience. We analyzed all available records for 43 patients diagnosed with DCMA between 2005 and 2015 at the Alberta Children's Hospital. All patients studied were Hutterite and homozygous for the causative DNAJC19 variant (c.130-1G>C, IVS3-1G>C) and had elevated levels of 3-methyglutaconic acid. We calculated a birth prevalence of 1.54 cases per 1000 total births in the Hutterite community. Children were small for gestational age at birth and frequently required supplemental nutrition (63%) or surgical placement of a gastrostomy tube (35%). Early mortality in this cohort was high (40%) at a median age of 13 months (range 4-294 months). Congenital anomalies were common as was dilated cardiomyopathy (50%), QT interval prolongation (83%), and developmental delay (95%). Tissue pathology was analyzed in a limited number of patients and demonstrated subendocardial fibrosis in the heart, macrovesicular steatosis and fibrosis in the liver, and structural abnormalities in mitochondria. This report provides clinical details for a cohort of children with DCMA and the first presentation of tissue pathology for this disorder. Despite sharing common genetic etiology and environment, the disease is highly heterogeneous for reasons that are not understood. DCMA is a clinically heterogeneous systemic mitochondrial disease with significant morbidity and mortality that is common in the Hutterite population of southern Alberta.
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Affiliation(s)
- Pranav Machiraju
- Department of Pediatrics, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Department of Cardiac Sciences and Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Vlad Degtiarev
- Department of Pediatrics, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Department of Cardiac Sciences and Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Dhwani Patel
- Department of Pediatrics, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Hassan Hazari
- Department of Pediatrics, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - R Brian Lowry
- Department of Pediatrics, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Alberta Congenital Anomalies Surveillance System, Calgary, Alberta, Canada
| | - Tanya Bedard
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Alberta Congenital Anomalies Surveillance System, Calgary, Alberta, Canada
| | - David Sinasac
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Alberta Precision Laboratories, Calgary, Alberta, Canada
| | - Marie-Anne Brundler
- Department of Pediatrics, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Alberta Precision Laboratories, Calgary, Alberta, Canada
- Department of Pathology & Laboratory Medicine, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Steven C Greenway
- Department of Pediatrics, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Department of Cardiac Sciences and Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Department of Biochemistry & Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Aneal Khan
- Department of Pediatrics, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Metabolics and Genetics in Calgary (M.A.G.I.C.) Clinic Ltd., Calgary, Alberta, Canada
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Gayathri N, Deepha S, Sharma S. Diagnosis of primary mitochondrial disorders -Emphasis on myopathological aspects. Mitochondrion 2021; 61:69-84. [PMID: 34592422 DOI: 10.1016/j.mito.2021.09.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 09/03/2021] [Accepted: 09/22/2021] [Indexed: 12/29/2022]
Abstract
Mitochondrial disorders are one of the most common neurometabolic disorders affecting all age groups. The phenotype-genotype heterogeneity in these disorders can be attributed to the dual genetic control on mitochondrial functions, posing a challenge for diagnosis. Though the advancement in the high-throughput sequencing and other omics platforms resulted in a "genetics-first" approach, the muscle biopsy remains the benchmark in most of the mitochondrial disorders. This review focuses on the myopathological aspects of primary mitochondrial disorders. The utility of muscle biopsy is not limited to analyse the structural abnormalities; rather it also proves to be a potential tool to understand the deranged sub-cellular functions.
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Affiliation(s)
- Narayanappa Gayathri
- Department of Neuropathology, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore 560 029, India.
| | - Sekar Deepha
- Department of Neuropathology, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore 560 029, India
| | - Shivani Sharma
- Department of Neuropathology, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore 560 029, India
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Lu JQ, Tarnopolsky MA. Mitochondrial neuropathy and neurogenic features in mitochondrial myopathy. Mitochondrion 2020; 56:52-61. [PMID: 33220502 DOI: 10.1016/j.mito.2020.11.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 10/25/2020] [Accepted: 11/02/2020] [Indexed: 01/21/2023]
Abstract
Mitochondrial diseases (MIDs) involve multiple organs including peripheral nerves and skeletal muscle. Mitochondrial neuropathy (MN) and mitochondrial myopathy (MM) are commonly associated and linked at the neuromuscular junction (NMJ). Herein we review MN in connection with neurogenic features of MM, and pathological evidence for the involvement of the peripheral nerve and NMJ in MID patients traditionally assumed to have predominantly MM. MN is not uncommon, but still likely under-reported, and muscle biopsies of MM commonly exhibit neurogenic features. Pathological examination remains the gold standard to assess the nerve and muscle changes in patients with MIDs. Ultrastructural studies by electron microscopy are often necessary to fully characterize the pathology of mitochondrial cytopathy in MN and MM.
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Affiliation(s)
- Jian-Qiang Lu
- Department of Pathology and Molecular Medicine/Neuropathology, McMaster University, Hamilton, Ontario, Canada.
| | - Mark A Tarnopolsky
- Department of Medicine/Neurology, McMaster University, Hamilton, Ontario, Canada; Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada
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Kerr M, Hume S, Omar F, Koo D, Barnes H, Khan M, Aman S, Wei XC, Alfuhaid H, McDonald R, McDonald L, Newell C, Sparkes R, Hittel D, Khan A. MITO-FIND: A study in 390 patients to determine a diagnostic strategy for mitochondrial disease. Mol Genet Metab 2020; 131:66-82. [PMID: 32980267 DOI: 10.1016/j.ymgme.2020.08.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 08/29/2020] [Accepted: 08/30/2020] [Indexed: 12/14/2022]
Abstract
Mitochondrial diseases, due to nuclear or mitochondrial genome mutations causing mitochondrial dysfunction, have a wide range of clinical features involving neurologic, muscular, cardiac, hepatic, visual, and auditory symptoms. Making a diagnosis of a mitochondrial disease is often challenging since there is no gold standard and traditional testing methods have required tissue biopsy which presents technical challenges and most patients prefer a non-invasive approach. Since a diagnosis invariably involves finding a disease-causing DNA variant, new approaches such as next generation sequencing (NGS) have the potential to make it easier to make a diagnosis. We evaluated the ability of our traditional diagnostic pathway (metabolite analysis, tissue neuropathology and respiratory chain enzyme activity) in 390 patients. The traditional diagnostic pathway provided a diagnosis of mitochondrial disease in 115 patients (29.50%). Analysis of mtDNA, tissue neuropathology, skin electron microscopy, respiratory chain enzyme analysis using inhibitor assays, blue native polyacrylamide gel electrophoresis were all statistically significant in distinguishing patients between a mitochondrial and non-mitochondrial diagnosis. From these 390 patients who underwent traditional analysis, we recruited 116 patients for the NGS part of the study (36 patients who had a mitochondrial diagnosis (MITO) and 80 patients who had no diagnosis (No-Dx)). In the group of 36 MITO patients, nuclear whole exome sequencing (nWES) provided a second diagnosis in 2 cases who already had a pathogenic variant in mtDNA, and a revised diagnosis (GLUL) in one case that had abnormal pathology but no pathogenic mtDNA variant. In the 80 NO-Dx patients, nWES found non-mitochondrial diagnosis in 26 patients and a mitochondrial diagnosis in 1 patient. A genetic diagnosis was obtained in 53/116 (45.70%) cases that were recruited for NGS, but not in 11/116 (9.48%) of cases with abnormal mitochondrial neuropathology. Our results show that a non-invasive, bigenomic sequencing (BGS) approach (using both a nWES and optimized mtDNA analysis to include large deletions) should be the first step in investigating for mitochondrial diseases. There may still be a role for tissue biopsy in unsolved cases or when the diagnosis is still not clear after NGS studies.
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Affiliation(s)
- Marina Kerr
- Departments of Medical Genetics and Pediatrics, University of Calgary Cumming School of Medicine, Alberta Children's Hospital Research Institute, Calgary, Alberta, Canada
| | - Stacey Hume
- Department of Medical Genetics, University of Alberta, Edmonton, Canada
| | - Fadya Omar
- Departments of Medical Genetics and Pediatrics, University of Calgary Cumming School of Medicine, Alberta Children's Hospital Research Institute, Calgary, Alberta, Canada
| | - Desmond Koo
- Departments of Medical Genetics and Pediatrics, University of Calgary Cumming School of Medicine, Alberta Children's Hospital Research Institute, Calgary, Alberta, Canada
| | - Heather Barnes
- Departments of Medical Genetics and Pediatrics, University of Calgary Cumming School of Medicine, Alberta Children's Hospital Research Institute, Calgary, Alberta, Canada
| | - Maida Khan
- Departments of Medical Genetics and Pediatrics, University of Calgary Cumming School of Medicine, Alberta Children's Hospital Research Institute, Calgary, Alberta, Canada
| | - Suhaib Aman
- Departments of Medical Genetics and Pediatrics, University of Calgary Cumming School of Medicine, Alberta Children's Hospital Research Institute, Calgary, Alberta, Canada
| | - Xing-Chang Wei
- Department of Radiology, Alberta Children's Hospital, University of Calgary Cumming School of Medicine, Calgary, Alberta, Canada
| | - Hanen Alfuhaid
- Departments of Medical Genetics and Pediatrics, University of Calgary Cumming School of Medicine, Alberta Children's Hospital Research Institute, Calgary, Alberta, Canada
| | - Roman McDonald
- Departments of Medical Genetics and Pediatrics, University of Calgary Cumming School of Medicine, Alberta Children's Hospital Research Institute, Calgary, Alberta, Canada
| | - Liam McDonald
- Departments of Medical Genetics and Pediatrics, University of Calgary Cumming School of Medicine, Alberta Children's Hospital Research Institute, Calgary, Alberta, Canada
| | - Christopher Newell
- Departments of Medical Genetics and Pediatrics, University of Calgary Cumming School of Medicine, Alberta Children's Hospital Research Institute, Calgary, Alberta, Canada
| | - Rebecca Sparkes
- Departments of Medical Genetics and Pediatrics, University of Calgary Cumming School of Medicine, Alberta Children's Hospital Research Institute, Calgary, Alberta, Canada
| | - Dustin Hittel
- Department of Biochemistry & Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Aneal Khan
- Departments of Medical Genetics and Pediatrics, University of Calgary Cumming School of Medicine, Alberta Children's Hospital Research Institute, Calgary, Alberta, Canada.
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Newell C, Khan A, Sinasac D, Shoffner J, Friederich MW, Van Hove JLK, Hume S, Shearer J, Sosova I. Hybrid gel electrophoresis using skin fibroblasts to aid in diagnosing mitochondrial disease. NEUROLOGY-GENETICS 2019; 5:e336. [PMID: 31192304 PMCID: PMC6515941 DOI: 10.1212/nxg.0000000000000336] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 02/08/2019] [Accepted: 03/01/2019] [Indexed: 12/26/2022]
Abstract
Objective We developed a novel, hybrid method combining both blue-native (BN-PAGE) and clear-native (CN-PAGE) polyacrylamide gel electrophoresis, termed BCN-PAGE, to perform in-gel activity stains on the mitochondrial electron transport chain (ETC) complexes in skin fibroblasts. Methods Four patients aged 46–65 years were seen in the Metabolic Clinic at Alberta Children's Hospital and investigated for mitochondrial disease and had BN-PAGE or CN-PAGE on skeletal muscle that showed incomplete assembly of complex V (CV) in each patient. Long-range PCR performed on muscle-extracted DNA identified 4 unique mitochondrial DNA (mtDNA) deletions spanning the ATP6 gene of CV. We developed a BCN-PAGE method in skin fibroblasts taken from the patients at the same time and compared the findings with those in skeletal muscle. Results In all 4 cases, BCN-PAGE in skin fibroblasts confirmed the abnormal CV activity found from muscle biopsy, suggesting that the mtDNA deletions involving ATP6 were most likely germline mutations that are associated with a clinical phenotype of mitochondrial disease. Conclusions The BCN-PAGE method in skin fibroblasts has a potential to be a less-invasive tool compared with muscle biopsy to screen patients for abnormalities in CV and other mitochondrial ETC complexes.
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Affiliation(s)
- Christopher Newell
- Department of Medical Genetics (C.N., A.K., D.S.) and Department of Pediatrics (A.K.), Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Canada; Atlanta (J. Shoffner), GA; Departments of Pediatrics (M.W.F., J.L.K.V.H.), Section of Clinical Genetics and Metabolism, University of Colorado; Department of Medical Genetics (S.H.), University of Alberta, Canada; Faculty of Kinesiology (J. Shearer), University of Calgary, Alberta, Canada; and Departments of Laboratory Medicine and Pathology (I.S.), University of Alberta, Edmonton, Canada
| | - Aneal Khan
- Department of Medical Genetics (C.N., A.K., D.S.) and Department of Pediatrics (A.K.), Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Canada; Atlanta (J. Shoffner), GA; Departments of Pediatrics (M.W.F., J.L.K.V.H.), Section of Clinical Genetics and Metabolism, University of Colorado; Department of Medical Genetics (S.H.), University of Alberta, Canada; Faculty of Kinesiology (J. Shearer), University of Calgary, Alberta, Canada; and Departments of Laboratory Medicine and Pathology (I.S.), University of Alberta, Edmonton, Canada
| | - David Sinasac
- Department of Medical Genetics (C.N., A.K., D.S.) and Department of Pediatrics (A.K.), Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Canada; Atlanta (J. Shoffner), GA; Departments of Pediatrics (M.W.F., J.L.K.V.H.), Section of Clinical Genetics and Metabolism, University of Colorado; Department of Medical Genetics (S.H.), University of Alberta, Canada; Faculty of Kinesiology (J. Shearer), University of Calgary, Alberta, Canada; and Departments of Laboratory Medicine and Pathology (I.S.), University of Alberta, Edmonton, Canada
| | - John Shoffner
- Department of Medical Genetics (C.N., A.K., D.S.) and Department of Pediatrics (A.K.), Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Canada; Atlanta (J. Shoffner), GA; Departments of Pediatrics (M.W.F., J.L.K.V.H.), Section of Clinical Genetics and Metabolism, University of Colorado; Department of Medical Genetics (S.H.), University of Alberta, Canada; Faculty of Kinesiology (J. Shearer), University of Calgary, Alberta, Canada; and Departments of Laboratory Medicine and Pathology (I.S.), University of Alberta, Edmonton, Canada
| | - Marisa W Friederich
- Department of Medical Genetics (C.N., A.K., D.S.) and Department of Pediatrics (A.K.), Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Canada; Atlanta (J. Shoffner), GA; Departments of Pediatrics (M.W.F., J.L.K.V.H.), Section of Clinical Genetics and Metabolism, University of Colorado; Department of Medical Genetics (S.H.), University of Alberta, Canada; Faculty of Kinesiology (J. Shearer), University of Calgary, Alberta, Canada; and Departments of Laboratory Medicine and Pathology (I.S.), University of Alberta, Edmonton, Canada
| | - Johan L K Van Hove
- Department of Medical Genetics (C.N., A.K., D.S.) and Department of Pediatrics (A.K.), Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Canada; Atlanta (J. Shoffner), GA; Departments of Pediatrics (M.W.F., J.L.K.V.H.), Section of Clinical Genetics and Metabolism, University of Colorado; Department of Medical Genetics (S.H.), University of Alberta, Canada; Faculty of Kinesiology (J. Shearer), University of Calgary, Alberta, Canada; and Departments of Laboratory Medicine and Pathology (I.S.), University of Alberta, Edmonton, Canada
| | - Stacey Hume
- Department of Medical Genetics (C.N., A.K., D.S.) and Department of Pediatrics (A.K.), Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Canada; Atlanta (J. Shoffner), GA; Departments of Pediatrics (M.W.F., J.L.K.V.H.), Section of Clinical Genetics and Metabolism, University of Colorado; Department of Medical Genetics (S.H.), University of Alberta, Canada; Faculty of Kinesiology (J. Shearer), University of Calgary, Alberta, Canada; and Departments of Laboratory Medicine and Pathology (I.S.), University of Alberta, Edmonton, Canada
| | - Jane Shearer
- Department of Medical Genetics (C.N., A.K., D.S.) and Department of Pediatrics (A.K.), Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Canada; Atlanta (J. Shoffner), GA; Departments of Pediatrics (M.W.F., J.L.K.V.H.), Section of Clinical Genetics and Metabolism, University of Colorado; Department of Medical Genetics (S.H.), University of Alberta, Canada; Faculty of Kinesiology (J. Shearer), University of Calgary, Alberta, Canada; and Departments of Laboratory Medicine and Pathology (I.S.), University of Alberta, Edmonton, Canada
| | - Iveta Sosova
- Department of Medical Genetics (C.N., A.K., D.S.) and Department of Pediatrics (A.K.), Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Canada; Atlanta (J. Shoffner), GA; Departments of Pediatrics (M.W.F., J.L.K.V.H.), Section of Clinical Genetics and Metabolism, University of Colorado; Department of Medical Genetics (S.H.), University of Alberta, Canada; Faculty of Kinesiology (J. Shearer), University of Calgary, Alberta, Canada; and Departments of Laboratory Medicine and Pathology (I.S.), University of Alberta, Edmonton, Canada
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Kozak I, Oystreck DT, Abu-Amero KK, Nowilaty SR, Alkhalidi H, Elkhamary SM, Mohamed S, Hamad MHA, Salih MA, Blakely EL, Taylor RW, Bosley TM. NEW OBSERVATIONS REGARDING THE RETINOPATHY OF GENETICALLY CONFIRMED KEARNS-SAYRE SYNDROME. Retin Cases Brief Rep 2018; 12:349-358. [PMID: 28296806 DOI: 10.1097/icb.0000000000000503] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
PURPOSE To report novel retinal findings in Kearns-Sayre syndrome and correlate degree of retinopathy with other clinical findings. METHODS Observational case series of patients from Saudi Arabia with retinal and neuroophthalmologic examinations, medical chart review, and mitochondrial genetic evaluation. RESULTS The three unrelated patients had progressive external ophthalmoplegia and pigmentary retinopathy bilaterally. Muscle biopsy in two of the cases revealed mitochondrial myopathy. All three had abnormal findings on neuroimaging and modestly reduced visual acuity in both eyes with a variable pigmentary retinopathy. One of the patients had bilateral subretinal fibrosis with a full-thickness macular hole in the right eye. All three patients had single, large-scale mitochondrial DNA (mtDNA) deletions (5.0-7.6 kb in size) with blood mtDNA heteroplasmy levels ranging from below 20% to 57%. Severity of pigmentary retinopathy did not correlate with severity of progressive external ophthalmoplegia, but did correspond grossly with electroretinographic abnormalities, just as the degree of ocular motility restriction and ptosis in each patient correlated with the size of their extraocular muscles on neuroimaging. In addition, the size of the single, large-scale mtDNA deletion and level of mtDNA heteroplasmy corresponded with degree of ocular motility restriction but not with severity of retinopathy. CONCLUSION Subretinal fibrosis and macular hole are novel retinal observations which expand clinical profile in Kearns-Sayre syndrome. Genetic testing for mtDNA deletions and heteroplasmy in blood, muscle biopsy, careful ocular and retinal examination including electroretinography, and imaging are indispensable tests for this condition.
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Affiliation(s)
- Igor Kozak
- King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia
| | - Darren T Oystreck
- Department of Ophthalmology, College of Medicine, King Saud University, Riyadh, Saudi Arabia
- The Division of Ophthalmology, Faculty of Health Sciences, University of Stellenbosch, Tygerberg, South Africa
| | - Khaled K Abu-Amero
- Department of Ophthalmology, College of Medicine, King Saud University, Riyadh, Saudi Arabia
- Department of Ophthalmology, College of Medicine, University of Florida, Jacksonville, Florida
| | | | | | | | - Sarar Mohamed
- Pediatrics, College of Medicine, King Saud University Riyadh, Saudi Arabia
| | | | - Mustafa A Salih
- Pediatrics, College of Medicine, King Saud University Riyadh, Saudi Arabia
| | - Emma L Blakely
- The Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Robert W Taylor
- The Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Thomas M Bosley
- Department of Ophthalmology, College of Medicine, King Saud University, Riyadh, Saudi Arabia
- The Wilmer Eye Institute, Johns Hopkins University, Baltimore, Maryland
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Masyeni S, Sintya E, Megawati D, Sukmawati NMH, Budiyasa DG, Aryastuti SA, Khairunisa SQ, Arijana I, Nasronudin N. Evaluation of antiretroviral effect on mitochondrial DNA depletion among HIV-infected patients in Bali. HIV AIDS-RESEARCH AND PALLIATIVE CARE 2018; 10:145-150. [PMID: 30104903 PMCID: PMC6072679 DOI: 10.2147/hiv.s166245] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Background Nucleoside reverse transcriptase inhibitors (NRTIs) are the cornerstone of highly active antiretroviral therapy combination regimens for HIV infection. Unfortunately, NRTIs have been noticeably associated with many adverse effects related to mitochondrial toxicity leading to mitochondrial deoxyribonucleic acid (mtDNA) depletion. However, similar mitochondrial dysfunction has recently been found even in antiretroviral therapy-naïve patients, suggesting HIV itself could contribute to this abnormality. In this study, we determine whether mtDNA depletion was present in either antiretroviral therapy-naïve or NRTI-treated patients at Sanjiwani Hospital, Bali, Indonesia. Patients and methods A cross-sectional study was conducted from the peripheral blood mononuclear cells of HIV patients. Specifically, the relative content of mtDNA (mtRNR1 gene) to nuclear DNA (ASPOLG gene) was determined by real-time polymerase chain reaction. Data were analyzed with SPSS 16.0 software and GraphPad Prism 7.02. Results A total of 84 samples (67 on NRTIs and 17 HIV-naïve) were suitable for analysis. We identified 21.4% of the samples (18/84) with mtDNA:nDNA ratio <1. Although it was not significant (P=0.121), the median mtDNA:nDNA ratio of HIV-naïve group was slightly higher (median 1.8; interquartile range [IQR]: 1.1-2.1) than NRTI-treated patients (median 1.5; IQR: 1.3-2.85). Tenofovir-based NRTI was more frequently used (73.13%) than zidovudine-based NRTI (26.86%). The period for which NRTI was used probably contributed to the ratio of mtDNA:nDNA. The median ratio of mtDNA:nDNA zidovudine-treated patients was slightly lower (median 1.2; IQR: 1.08-1.98) when compared to tenofovir-based NRTI (median 1.6; IQR: 1.05-2.10), with the median period of former treatment being significantly longer (P<0.001). Although these data overall indicate that NRTI treatment had no effect on mtDNA:nDNA ratios, patients who undergo more than 12 months of NRTIs treatment show a decrease in the ratio; however, further study is required. Conclusion Almost one-fourth of the samples showed a lower mtDNA:nDNA ratio. The decreasing of the ratio mtDNA:nDNA was most likely present after 12 months of NRTI treatment.
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Affiliation(s)
- Sri Masyeni
- Faculty of Medicine and Health Sciences, University of Warmadewa, Denpasar, Bali, Indonesia,
| | - Erly Sintya
- Faculty of Medicine and Health Sciences, University of Warmadewa, Denpasar, Bali, Indonesia,
| | - Dewi Megawati
- Faculty of Medicine and Health Sciences, University of Warmadewa, Denpasar, Bali, Indonesia,
| | | | - Dewa Ga Budiyasa
- Internal Medicine Department, Sanjiwani Hospital, Gianyar, Bali, Indonesia
| | - Sri Agung Aryastuti
- Faculty of Medicine and Health Sciences, University of Warmadewa, Denpasar, Bali, Indonesia,
| | - Siti Qamariyah Khairunisa
- Indonesia-Japan Collaborative Research Center for Emerging and Reemerging Infectious Diseases, Institute of Tropical Disease, Airlangga University, Surabaya, Indonesia
| | - Igkn Arijana
- Histology Department of Faculty of Medicine, Udayana University, Denpasar, Bali, Indonesia
| | - N Nasronudin
- Indonesia-Japan Collaborative Research Center for Emerging and Reemerging Infectious Diseases, Institute of Tropical Disease, Airlangga University, Surabaya, Indonesia
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11
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McAfee JL, Warren CB, Prayson RA. Ultrastructural examination of skin biopsies may assist in diagnosing mitochondrial cytopathy when muscle biopsies yield negative results. Ann Diagn Pathol 2017; 29:41-45. [PMID: 28807341 DOI: 10.1016/j.anndiagpath.2017.02.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 02/17/2017] [Indexed: 11/16/2022]
Abstract
Ultrastructural evaluation of skin biopsies has been utilized for diagnosis of mitochondrial disease. This study investigates how frequently skin biopsies reveal mitochondrial abnormalities, correlates skin and muscle biopsy findings, and describes clinical diagnoses rendered following the evaluation. A retrospective review of surgical pathology reports from 1990 to 2015 identified skin biopsies examined by electron microscopy for suspected metabolic disease. A total of 630 biopsies were included from 615 patients. Of these patients, 178 also underwent a muscle biopsy. Of the 630 skin biopsies, 75 (12%) showed ultrastructural abnormalities and 34 (5%) specifically showed mitochondrial abnormalities including increased size (n=27), reduced or abnormal cristae (n=23), dense matrices (n=20), and increased number (n=8). Additional findings included lysosomal abnormalities (n=13), lipid accumulation (n=2) or glycogen accumulation (n=1). Of the 34 patients with mitochondrial abnormalities on skin biopsy, 20 also had muscle biopsies performed and nine showed abnormalities suggestive of a mitochondrial disorder including absent cytochrome oxidase staining (n=2), increased subsarcolemmal NADH, SDH, or cytochrome oxidase staining (n=1), or ultrastructural findings including large mitochondrial size (n=5), abnormal mitochondrial structure (n=5), and increased mitochondrial number (n=4). The most common presenting symptoms were intellectual disability (n=13), seizures (n=12), encephalopathy (n=9), and gastrointestinal disturbances (n=9). At last known follow-up, 12 patients had a definitive diagnosis of a mitochondrial disorder. One patient each had Complex I deficiency, Complex III deficiency, Charcot-Marie-Tooth disease, pyruvate dehydrogenase deficiency, and Phelan-McDermid syndrome. Our results suggest that skin biopsy sometimes yields diagnostic clues suggestive of a mitochondrial cytopathy in cases with a negative muscle biopsy.
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Affiliation(s)
- John L McAfee
- Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH, USA
| | | | - Richard A Prayson
- Department of Anatomic Pathology, Cleveland Clinic, Cleveland, OH, USA.
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12
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Niu FN, Meng HL, Chang LL, Wu HY, Li WP, Liu RY, Wang HT, Zhang B, Xu Y. Mitochondrial dysfunction and cerebral metabolic abnormalities in patients with mitochondrial encephalomyopathy subtypes: Evidence from proton MR spectroscopy and muscle biopsy. CNS Neurosci Ther 2017; 23:686-697. [PMID: 28695670 DOI: 10.1111/cns.12714] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2017] [Revised: 06/01/2017] [Accepted: 06/06/2017] [Indexed: 11/27/2022] Open
Abstract
AIMS Accumulated evidence indicates that cerebral metabolic features, evaluated by proton magnetic resonance spectroscopy (1 H-MRS), are sensitive to early mitochondrion dysfunction associated with mitochondrial encephalomyopathy (ME). The metabolite ratios of lactate (lac)/Cr, N-acetyl aspartate (NAA)/creatine (Cr), total choline (tCho)/Cr, and myoinositol (mI)/Cr are measured in the infarct-like lesions by 1 H-MRS and may reveal metabolic changes associated with ME. However, the application of this molecular imaging technique in the investigation of the pathology of ME subtypes is unknown. METHODS In this study, cerebral metabolic features of pathologically diagnosed ME cases, that is, 19 mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS); nine chronic progressive external ophthalmoplegia (CPEO); and 23 healthy controls, were investigated using 1 H-MRS. Receiver operating characteristics (ROC) analysis was used to evaluate the diagnostic power of the cerebral metabolites. Histochemical evaluation was carried out on muscle tissues derived from biopsy to assess the abnormal mitochondrial proliferation. The association between cerebral metabolic and mitochondrial cytopathy was examined by correlation analysis. RESULTS Patients with MELAS or CPEO exhibited a significantly higher Lac/Cr ratio and a lower NAA/Cr ratio compared with controls. The ROC curve of Lac/Cr ratio indicated prominent discrimination between MELAS or CPEO and healthy control subjects, whereas the NAA/Cr ratio may present diagnostic power in the distinction of MELAS from CPEO. Lower NAA/Cr ratio was associated with higher Lac/Cr in MELAS, but not in CPEO. Furthermore, higher ragged-red fibers (RRFs) percentages were associated with elevated Lac/Cr and reduced NAA/Cr ratios, notably in MELAS. This association was not noted in the case of mI/Cr ratio. CONCLUSIONS Mitochondrial cytopathy (lactic acidosis and RRFs on muscle biopsy) was associated with neuronal viability but not glial proliferation, notably in MELAS. Mitochondrial neuronopathy and neuronal vulnerability are considered significant causes in the pathogenesis of MELAS, particularly with regard to stroke-like episodes.
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Affiliation(s)
- Feng-Nan Niu
- Department of Pathology, Drum Tower Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, China
| | - Hai-Lan Meng
- Department of Neurology, Drum Tower Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, China
| | - Lei-Lei Chang
- Department of Neurology, Drum Tower Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, China
| | - Hong-Yan Wu
- Department of Pathology, Drum Tower Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, China
| | - Wei-Ping Li
- Department of Radiology, Drum Tower Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, China
| | - Ren-Yuan Liu
- Department of Neurology, Drum Tower Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, China
| | - Hui-Ting Wang
- Department of Radiology, Drum Tower Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, China
| | - Bing Zhang
- Department of Radiology, Drum Tower Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, China
| | - Yun Xu
- Department of Neurology, Drum Tower Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, China
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13
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Phadke R. Myopathology of Adult and Paediatric Mitochondrial Diseases. J Clin Med 2017; 6:jcm6070064. [PMID: 28677615 PMCID: PMC5532572 DOI: 10.3390/jcm6070064] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 06/21/2017] [Accepted: 06/28/2017] [Indexed: 01/09/2023] Open
Abstract
Mitochondria are dynamic organelles ubiquitously present in nucleated eukaryotic cells, subserving multiple metabolic functions, including cellular ATP generation by oxidative phosphorylation (OXPHOS). The OXPHOS machinery comprises five transmembrane respiratory chain enzyme complexes (RC). Defective OXPHOS gives rise to mitochondrial diseases (mtD). The incredible phenotypic and genetic diversity of mtD can be attributed at least in part to the RC dual genetic control (nuclear DNA (nDNA) and mitochondrial DNA (mtDNA)) and the complex interaction between the two genomes. Despite the increasing use of next-generation-sequencing (NGS) and various omics platforms in unravelling novel mtD genes and pathomechanisms, current clinical practice for investigating mtD essentially involves a multipronged approach including clinical assessment, metabolic screening, imaging, pathological, biochemical and functional testing to guide molecular genetic analysis. This review addresses the broad muscle pathology landscape including genotype–phenotype correlations in adult and paediatric mtD, the role of immunodiagnostics in understanding some of the pathomechanisms underpinning the canonical features of mtD, and recent diagnostic advances in the field.
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Affiliation(s)
- Rahul Phadke
- Division of Neuropathology, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, UCLH NHS Foundation Trust, London WC1N 3BG, UK.
- Dubowitz Neuromuscular Centre, Great Ormond Street Hospital for Children NHS Foundation Trust, London WC1N 3JH, UK.
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14
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Wang Y, Smith C, Parboosingh JS, Khan A, Innes M, Hekimi S. Pathogenicity of two COQ7 mutations and responses to 2,4-dihydroxybenzoate bypass treatment. J Cell Mol Med 2017; 21:2329-2343. [PMID: 28409910 PMCID: PMC5618687 DOI: 10.1111/jcmm.13154] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Accepted: 02/10/2017] [Indexed: 01/22/2023] Open
Abstract
Primary ubiquinone (co‐enzyme Q) deficiency results in a wide range of clinical features due to mitochondrial dysfunction. Here, we analyse and characterize two mutations in the ubiquinone biosynthetic gene COQ7. One mutation from the only previously identified patient (V141E), and one (L111P) from a 6‐year‐old girl who presents with spasticity and bilateral sensorineural hearing loss. We used patient fibroblast cell lines and a heterologous expression system to show that both mutations lead to loss of protein stability and decreased levels of ubiquinone that correlate with the severity of mitochondrial dysfunction. The severity of L111P is enhanced by the particular COQ7 polymorphism (T103M) that the patient carries, but not by a mitochondrial DNA mutation (A1555G) that is also present in the patient and that has been linked to aminoglycoside‐dependent hearing loss. We analysed treatment with the unnatural biosynthesis precursor 2,4‐dihydroxybenzoate (DHB), which can restore ubiquinone synthesis in cells completely lacking the enzymatic activity of COQ7. We find that the treatment is not beneficial for every COQ7 mutation and its outcome depends on the extent of enzyme activity loss.
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Affiliation(s)
- Ying Wang
- Department of Biology, McGill University, Montréal, Quebec, Canada
| | - Christopher Smith
- Department of Medical Genetics, Alberta Children's Hospital, University of Calgary, Calgary, Alberta, Canada
| | - Jillian S Parboosingh
- Department of Medical Genetics, Alberta Children's Hospital, University of Calgary, Calgary, Alberta, Canada.,Alberta Children's Hospital, Research Institute for Child and Maternal Health, University of Calgary, Calgary, Alberta, Canada
| | - Aneal Khan
- Metabolic Diseases Clinic, Alberta Children's Hospital, University of Calgary, Calgary, Alberta, Canada
| | - Micheil Innes
- Department of Medical Genetics, Alberta Children's Hospital, University of Calgary, Calgary, Alberta, Canada.,Alberta Children's Hospital, Research Institute for Child and Maternal Health, University of Calgary, Calgary, Alberta, Canada
| | - Siegfried Hekimi
- Department of Biology, McGill University, Montréal, Quebec, Canada
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15
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Cruz S, Taipa R, Nogueira C, Pereira C, Almeida LS, Neiva R, Geraldes T, Guimarães A, Melo‐Pires M, Vilarinho L. Clinical, biochemical, molecular, and histological features of 65 Portuguese patients with mitochondrial disorders. Muscle Nerve 2017; 56:868-872. [DOI: 10.1002/mus.25593] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/23/2017] [Indexed: 11/12/2022]
Affiliation(s)
- Simão Cruz
- Neurology DepartmentHospital Prof. Doutor Fernando FonsecaIC 19, 2720‐276, Amadora Portugal
| | - Ricardo Taipa
- Neuropathology UnitHospital Santo António / Centro Hospitalar do PortoPorto Portugal
| | - Célia Nogueira
- Newborn screening, Metabolism and Genetics Unit, Human Genetics DepartmentDr. Ricardo Jorge National Health InstitutePorto Portugal
| | - Cristina Pereira
- Newborn screening, Metabolism and Genetics Unit, Human Genetics DepartmentDr. Ricardo Jorge National Health InstitutePorto Portugal
| | - Lígia S. Almeida
- Newborn screening, Metabolism and Genetics Unit, Human Genetics DepartmentDr. Ricardo Jorge National Health InstitutePorto Portugal
| | - Raquel Neiva
- Newborn screening, Metabolism and Genetics Unit, Human Genetics DepartmentDr. Ricardo Jorge National Health InstitutePorto Portugal
| | - Tiago Geraldes
- Neurology DepartmentHospital Garcia de OrtaAlmada Portugal
| | - António Guimarães
- Neuropathology UnitHospital Santo António / Centro Hospitalar do PortoPorto Portugal
| | - Manuel Melo‐Pires
- Neuropathology UnitHospital Santo António / Centro Hospitalar do PortoPorto Portugal
| | - Laura Vilarinho
- Newborn screening, Metabolism and Genetics Unit, Human Genetics DepartmentDr. Ricardo Jorge National Health InstitutePorto Portugal
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16
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Abstract
In this chapter we review the optimal imaging modalities for subacute and chronic stroke. We discuss the utility of computed tomography (CT) and multimodal CT imaging. Further, we analyze the importance of specific magnetic resonance imaging sequences, such as diffusion-weighted imaging for acute ischemic stroke, T2/fluid-attenuated inversion recovery for subacute and chronic stroke, and susceptibility imaging for detection of intracranial hemorrhages. Different ischemic stroke mechanisms are reviewed, and how these imaging modalities may aid in the determination of such. Further, we analyze how topographic patterns in ischemic stroke may provide important clues to the diagnosis, in addition to the temporal evolution of the stroke. Lastly, specific cerebrovascular occlusive diseases are reviewed, with emphasis on the optimal imaging modalities and their findings in each condition.
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17
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Abstract
BACKGROUND the maternally inherited MTTL1 A3243G mutation in the mitochondrial genome causes MelaS (Mitochondrial encephalopathy lactic acidosis with Stroke-like episodes), a condition that is multisystemic but affects primarily the nervous system. Significant intra-familial variation in phenotype and severity of disease is well recognized. METHODS retrospective and ongoing study of an extended family carrying the MTTL1 A3243G mutation with multiple symptomatic individuals. tissue heteroplasmy is reviewed based on the clinical presentations, imaging studies, laboratory findings in affected individuals and pathological material obtained at autopsy in two of the family members. RESULTS there were seven affected individuals out of thirteen members in this three generation family who each carried the MTTL1 A3243G mutation. the clinical presentations were varied with symptoms ranging from hearing loss, migraines, dementia, seizures, diabetes, visual manifestations, and stroke like episodes. three of the family members are deceased from MelaS or to complications related to MelaS. CONCLUSIONS the results of the clinical, pathological and radiological findings in this family provide strong support to the current concepts of maternal inheritance, tissue heteroplasmy and molecular pathogenesis in MelaS. neurologists (both adult and paediatric) are the most likely to encounter patients with MelaS in their practice. genetic counselling is complex in view of maternal inheritance and heteroplasmy. newer therapeutic options such as arginine are being used for acute and preventative management of stroke like episodes.
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18
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Pompe Disease: Diagnosis and Management. Evidence-Based Guidelines from a Canadian Expert Panel. Can J Neurol Sci 2016; 43:472-85. [DOI: 10.1017/cjn.2016.37] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
AbstractPompe disease is a lysosomal storage disorder caused by a deficiency of the enzyme acid alpha-glucosidase. Patients have skeletal muscle and respiratory weakness with or without cardiomyopathy. The objective of our review was to systematically evaluate the quality of evidence from the literature to formulate evidence-based guidelines for the diagnosis and management of patients with Pompe disease. The literature review was conducted using published literature, clinical trials, cohort studies and systematic reviews. Cardinal treatment decisions produced seven management guidelines and were assigned a GRADE classification based on the quality of evidence in the published literature. In addition, six recommendations were made based on best clinical practices but with insufficient data to form a guideline. Studying outcomes in rare diseases is challenging due to the small number of patients, but this is in particular the reason why we believe that informed treatment decisions need to consider the quality of the evidence.
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19
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Zhang Y, Ma Y, Bu D, Liu H, Xia C, Zhang Y, Zhu S, Pan H, Pei P, Zheng X, Wang S, Xu Y, Qi Y. Deletion of a 4977-bp Fragment in the Mitochondrial Genome Is Associated with Mitochondrial Disease Severity. PLoS One 2015; 10:e0128624. [PMID: 26024530 PMCID: PMC4449107 DOI: 10.1371/journal.pone.0128624] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Accepted: 04/30/2015] [Indexed: 12/22/2022] Open
Abstract
Large deletions in mitochondrial DNA (mtDNA) may be involved in the pathogenesis of mitochondrial disease. In this study, we investigated the relationship between a 4,977-bp deletion in the mitochondrial genome (ΔmtDNA4977) and the severity of clinical symptoms in patients with mitochondrial disease lacking known point mutations. A total of 160 patients with mitochondrial disease and 101 healthy controls were recruited for this study. The copy numbers of ΔmtDNA4977 and wild-type mtDNA were determined by real-time quantitative PCR and analyzed using Spearman’s bivariate correlation analysis, t-tests, or one-way ANOVA. The overall ΔmtDNA4977 copy number per cell and the proportion of mtDNA4977 relative to the total wild-type mtDNA, increased with patient age and symptom severity. Surprisingly, the total mtDNA copy number decreased with increasing symptom severity. Our analyses revealed that increases in the proportion and total copy number of ΔmtDNA4977 in the blood may be associated with disease severity in patients with mitochondrial dysfunction.
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Affiliation(s)
- Yanchun Zhang
- Department of Central Laboratory, Peking University First Hospital, No. 8, West District, Beijing, 100034, China
| | - Yinan Ma
- Department of Central Laboratory, Peking University First Hospital, No. 8, West District, Beijing, 100034, China
- * E-mail: (YM); (YQ)
| | - Dingfang Bu
- Department of Central Laboratory, Peking University First Hospital, No. 8, West District, Beijing, 100034, China
| | - Hui Liu
- Department of Respiratory, Beijing Children’s Hospital, Beijing, 100045, China
| | - Changyu Xia
- Department of Clinical Laboratory, Peking University First Hospital, No. 8, West District, Beijing, 100034, China
| | - Ying Zhang
- Department of Central Laboratory, Peking University First Hospital, No. 8, West District, Beijing, 100034, China
| | - Sainan Zhu
- Department of Biostatistics, Peking University First Hospital, No. 8, West District, Beijing, 100034, China
| | - Hong Pan
- Department of Central Laboratory, Peking University First Hospital, No. 8, West District, Beijing, 100034, China
| | - Pei Pei
- Department of Central Laboratory, Peking University First Hospital, No. 8, West District, Beijing, 100034, China
| | - Xuefei Zheng
- Department of Central Laboratory, Peking University First Hospital, No. 8, West District, Beijing, 100034, China
| | - Songtao Wang
- Department of Central Laboratory, Peking University First Hospital, No. 8, West District, Beijing, 100034, China
| | - Yufeng Xu
- Department of Central Laboratory, Peking University First Hospital, No. 8, West District, Beijing, 100034, China
| | - Yu Qi
- Department of Central Laboratory, Peking University First Hospital, No. 8, West District, Beijing, 100034, China
- * E-mail: (YM); (YQ)
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20
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Nozuma S, Okamoto Y, Higuchi I, Yuan J, Hashiguchi A, Sakiyama Y, Yoshimura A, Higuchi Y, Takashima H. Clinical and Electron Microscopic Findings in Two Patients with Mitochondrial Myopathy Associated with Episodic Hyper-creatine Kinase-emia. Intern Med 2015; 54:3209-14. [PMID: 26666615 DOI: 10.2169/internalmedicine.54.5444] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mitochondrial myopathy with episodic hyper-creatine kinase (CK)-emia (MIMECK) is a new disease entity characterized by episodic or persistent muscle weakness and elevated CK levels. We herein report two cases of MIMECK with the findings of histopathological studies. Histopathological examinations revealed strongly succinate dehydrogenase-reactive vessels. Electron microscopy showed abnormal mitochondria in the vessels and proliferating and vacuolated mitochondria under the sarcolemma. Both patients exhibited recurrent severe myalgia, weakness and increased CK levels. L-arginine treatment significantly ameliorated their muscle symptoms. These findings indicate that mitochondrial angiopathy plays an important role in the pathophysiology of MIMECK. L-arginine may be a potential therapeutic agent for this disorder.
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Affiliation(s)
- Satoshi Nozuma
- Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences, Japan
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21
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D'Erchia AM, Atlante A, Gadaleta G, Pavesi G, Chiara M, De Virgilio C, Manzari C, Mastropasqua F, Prazzoli GM, Picardi E, Gissi C, Horner D, Reyes A, Sbisà E, Tullo A, Pesole G. Tissue-specific mtDNA abundance from exome data and its correlation with mitochondrial transcription, mass and respiratory activity. Mitochondrion 2014; 20:13-21. [PMID: 25446395 DOI: 10.1016/j.mito.2014.10.005] [Citation(s) in RCA: 121] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Revised: 09/23/2014] [Accepted: 10/29/2014] [Indexed: 01/12/2023]
Abstract
Eukaryotic cells contain a population of mitochondria, variable in number and shape, which in turn contain multiple copies of a tiny compact genome (mtDNA) whose expression and function is strictly coordinated with the nuclear one. mtDNA copy number varies between different cell or tissues types, both in response to overall metabolic and bioenergetics demands and as a consequence or cause of specific pathological conditions. Here we present a novel and reliable methodology to assess the effective mtDNA copy number per diploid genome by investigating off-target reads obtained by whole-exome sequencing (WES) experiments. We also investigate whether and how mtDNA copy number correlates with mitochondrial mass, respiratory activity and expression levels. Analyzing six different tissues from three age- and sex-matched human individuals, we found a highly significant linear correlation between mtDNA copy number estimated by qPCR and the frequency of mtDNA off target WES reads. Furthermore, mtDNA copy number showed highly significant correlation with mitochondrial gene expression levels as measured by RNA-Seq as well as with mitochondrial mass and respiratory activity. Our methodology makes thus feasible, at a large scale, the investigation of mtDNA copy number in diverse cell-types, tissues and pathological conditions or in response to specific treatments.
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Affiliation(s)
- Anna Maria D'Erchia
- Dipartimento di Bioscienze, Biotecnologie e Biofarmaceutica, Università degli Studi di Bari Aldo Moro, Via Orabona 4, Bari 70126, Italy
| | - Anna Atlante
- Istituto di Biomembrane e Bioenergetica, CNR, via Amendola 165/A, Bari 70126, Italy
| | - Gemma Gadaleta
- Dipartimento di Bioscienze, Biotecnologie e Biofarmaceutica, Università degli Studi di Bari Aldo Moro, Via Orabona 4, Bari 70126, Italy
| | - Giulio Pavesi
- Dipartimento di Bioscienze, Università degli Studi di Milano, Via Celoria 26, Milano 20133, Italy
| | - Matteo Chiara
- Dipartimento di Bioscienze, Università degli Studi di Milano, Via Celoria 26, Milano 20133, Italy
| | - Caterina De Virgilio
- Dipartimento di Bioscienze, Biotecnologie e Biofarmaceutica, Università degli Studi di Bari Aldo Moro, Via Orabona 4, Bari 70126, Italy
| | - Caterina Manzari
- Istituto di Biomembrane e Bioenergetica, CNR, via Amendola 165/A, Bari 70126, Italy
| | - Francesca Mastropasqua
- Dipartimento di Bioscienze, Biotecnologie e Biofarmaceutica, Università degli Studi di Bari Aldo Moro, Via Orabona 4, Bari 70126, Italy
| | - Gian Marco Prazzoli
- Dipartimento di Bioscienze, Università degli Studi di Milano, Via Celoria 26, Milano 20133, Italy
| | - Ernesto Picardi
- Dipartimento di Bioscienze, Biotecnologie e Biofarmaceutica, Università degli Studi di Bari Aldo Moro, Via Orabona 4, Bari 70126, Italy
| | - Carmela Gissi
- Dipartimento di Bioscienze, Università degli Studi di Milano, Via Celoria 26, Milano 20133, Italy
| | - David Horner
- Dipartimento di Bioscienze, Università degli Studi di Milano, Via Celoria 26, Milano 20133, Italy
| | - Aurelio Reyes
- Mitochondrial Biology Unit, Medical Research Council, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 0XY, United Kingdom
| | - Elisabetta Sbisà
- Istituto di Tecnologie Biomediche- Sede di Bari, CNR, Via Amendola 122/D, Bari 70126, Italy
| | - Apollonia Tullo
- Istituto di Tecnologie Biomediche- Sede di Bari, CNR, Via Amendola 122/D, Bari 70126, Italy
| | - Graziano Pesole
- Dipartimento di Bioscienze, Biotecnologie e Biofarmaceutica, Università degli Studi di Bari Aldo Moro, Via Orabona 4, Bari 70126, Italy; Istituto di Biomembrane e Bioenergetica, CNR, via Amendola 165/A, Bari 70126, Italy.
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22
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Khambatta S, Nguyen DL, Beckman TJ, Wittich CM. Kearns-Sayre syndrome: a case series of 35 adults and children. Int J Gen Med 2014; 7:325-32. [PMID: 25061332 PMCID: PMC4086664 DOI: 10.2147/ijgm.s65560] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Background Kearns–Sayre syndrome (KSS) is a rare mitochondrial cytopathy, first described at Mayo Clinic in 1958. Aims We aimed to define patient and disease characteristics in a large group of adult and pediatric patients with KSS. Methods We retrospectively searched the Mayo Clinic medical index patient database for the records of patients with KSS between 1976 and 2009. The 35 patients identified with KSS were analyzed in terms of demographic characteristics, presenting signs and symptoms, diagnostic features, clinical evolution, and associations between disease features and the development of disability. Results The mean (standard [SD]) age at KSS presentation was 17 (10) years, but the mean age at diagnosis was 26 (15) years. Ophthalmologic symptoms developed in all patients, and neurologic and cardiac involvement was common. Only four patients (11%) in the series died, but all deaths were from sudden cardiac events. The development of physical disability was significantly associated with cognitive decline (P=0.004) but not with other clinical features, such as sex or sudden cardiac death. Conclusion We report the largest case series to date of patients with KSS from a single institution. In addition to the conduction system abnormalities identified in previous series, our cohort included patients with syncope and sudden cardiac death. This underscores the need to consider formal electrophysiologic studies and prophylactic defibrillators in patients with KSS.
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Affiliation(s)
| | - Douglas L Nguyen
- Division of General Internal Medicine, Mayo Clinic, Rochester, MN, USA
| | - Thomas J Beckman
- Division of General Internal Medicine, Mayo Clinic, Rochester, MN, USA
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Ghaoui R, Clarke N, Hollingworth P, Needham M. Muscle disorders: the latest investigations. Intern Med J 2014; 43:970-8. [PMID: 24004391 DOI: 10.1111/imj.12234] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Accepted: 06/22/2013] [Indexed: 12/14/2022]
Abstract
Patients with muscle disorders can present a diagnostic challenge to physicians because of the different ways they can present and the large number of different underlying causes. Recognition of the 'myopathic phenotype' coupled with investigations usually including electrodiagnostic and histological investigations have been essential for diagnosing the underlying cause of a myopathy. Despite these standard investigations, some patients can remain undiagnosed. New tests including more specific antibody tests for immune-mediated myopathies and the introduction of next-generation sequencing promise to revolutionise diagnostic approaches for immune and inherited myopathies, but clinical expertise remains essential to choose the most appropriate tests and interpret the results. The aim of this review is to provide an overview of the different presentations to the neuromuscular clinic and the latest investigations that can be helpful in the diagnosis of muscle disorders.
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Affiliation(s)
- R Ghaoui
- Department of Neurology, Royal North Shore Hospital, Sydney, New South Wales, Australia.
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Liu AH, Niu FN, Chang LL, Zhang B, Liu Z, Chen JY, Zhou Q, Wu HY, Xu Y. High cytochrome c oxidase expression links to severe skeletal energy failure by (31)P-MRS spectroscopy in mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes. CNS Neurosci Ther 2014; 20:509-14. [PMID: 24674659 DOI: 10.1111/cns.12257] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Revised: 02/25/2014] [Accepted: 02/26/2014] [Indexed: 11/26/2022] Open
Abstract
AIMS The purpose of this study was to evaluate the energy metabolism and mitochondrial function in skeletal muscle from patients with Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) or chronic progressive external ophthalmoplegia (CPEO) using phosphorus magnetic resonance spectroscopy ((31)P-MRS), to determine whether abnormally increasing cytochrome c oxidase (COX), as detected in muscle biopsy, could be a cause for MELAS. METHODS (31)P-MRS was performed on the quadriceps femoris muscle of 12 healthy volunteers and 11 patients diagnosed as MELAS or CPEO by muscle biopsy and genetic analysis. All subjects experienced a state of rest, 5-min exercise, and 5-min recovery protocol in a supine position. RESULTS Compared to CPEO, MELAS patients typically exhibited COX-positive ragged-red fibers (RRFs) as well as strongly SDH-positive blood vessels (SSVs). However, based on (31)P-MRS results, MELAS showed a higher inorganic phosphate (Pi)/phosphocreatine (PCr) ratio and lower ATP/PCr ratio during exercise and delayed Pi/PCr and ATP/PCr recovery to normal. CONCLUSIONS This study suggests that high COX expression contributes to severe skeletal energy failure by (31)P-MRS spectroscopy in MELAS.
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Affiliation(s)
- Ai-Hua Liu
- Department of Neurology, Drum Tower Hospital of Nanjing Medical University, Nanjing, China
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Finsterer J, Höftberger R, Rolinski B, Stöllberger C, Wöhrer A, Winkler WB. Presumed mitochondrial disease manifesting with recurrent syncopes. J Cardiovasc Med (Hagerstown) 2014; 15:167-9. [PMID: 24522085 DOI: 10.2459/jcm.0b013e328365c0e0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
OBJECTIVES Loss of consciousness may be due to neurological or cardiac involvement in mitochondrial disease, and is often difficult to attribute to either cause, as in the following case. CASE REPORT A 67-year-old man with hypertension, diabetes, elevated serum creatine kinase, glaucoma, optic atrophy, and vertigo had experienced recurrent losses of consciousness since 63 years of age. Diagnostic work-up revealed paroxysmal supraventricular arrhythmias, hyperlipidemia, steatosis hepatis, renal insufficiency, polyneuropathy, first-degree atrio-ventricular block, orthostasis, and cataract. From the age of 66 years, he developed tonic-clonic seizures. Electrocardiography loop recording showed some losses of consciousness as associated with supraventricular tachycardias and others with epileptic activity or arterial hypotension. Neurological investigations and muscle biopsy were indicative of mitochondrial disease with multisystem involvement. Losses of consciousness disappeared after catheter ablation and treatment with levetiracetam. CONCLUSION Recurrent loss of consciousness in mitochondrial disease may not only be due to arrhythmias but also seizure activity, or autonomic neuropathy. Arrhythmias, seizures, and polyneuropathy may have a common underlying cause affecting various tissues.
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Affiliation(s)
- Josef Finsterer
- aKrankenanstalt Rudolfstiftung bClinical Institute of Neurology, Medical University Vienna cInstitute of Clinical Chemistry, Academic Hospital München-Schwabing, Germany dMedical Department, Krankenanstalt Rudolfstiftung, Vienna, Austria
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Tenney JR, Prada CE, Hopkin RJ, Hallinan BE. Early spinal cord and brainstem involvement in infantile Leigh syndrome possibly caused by a novel variant. J Child Neurol 2013; 28:1681-5. [PMID: 23143729 DOI: 10.1177/0883073812464273] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Leigh syndrome, due to a dysfunction of mitochondrial energy metabolism, is a genetically heterogeneous and progressive neurologic disorder that usually occurs in infancy and childhood. Its clinical presentation and neuroimaging findings can be variable, especially early in the course of the disease. This report presents a patient with infantile Leigh syndrome who had atypical radiologic findings on serial neuroimaging studies with early and severe involvement of the cervical spinal cord and brainstem and injury to the thalami and basal ganglia occurring only late in the clinical course. Postmortem microscopic examination supported this timing of injury within the central nervous system. In addition, mitochondrial deoxyribonucleic acid sequencing showed a novel homoplasmic variant that could be responsible for this unique lethal form of Leigh syndrome.
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Affiliation(s)
- Jeffrey R Tenney
- 1Department of Pediatrics, Division of Neurology, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH, USA
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Liang C, Ahmad K, Sue CM. The broadening spectrum of mitochondrial disease: shifts in the diagnostic paradigm. Biochim Biophys Acta Gen Subj 2013; 1840:1360-7. [PMID: 24239706 DOI: 10.1016/j.bbagen.2013.10.040] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2013] [Revised: 10/21/2013] [Accepted: 10/26/2013] [Indexed: 01/08/2023]
Abstract
BACKGROUND The diagnosis of mitochondrial disease requires a complex synthesis of clinical, biochemical, histological, and genetic investigations. An expanding number of mitochondrial diseases are being recognized, despite their phenotypic diversity, largely due to improvements in methods to detect mutations in affected individuals and the discovery of genes contributing to mitochondrial function. Improved understanding of the investigational pitfalls and the development of new laboratory methodologies that lead to a molecular diagnosis have necessitated the field to rapidly adopt changes to its diagnostic approach. SCOPE OF REVIEW We review the clinical, investigational and genetic challenges that have resulted in shifts to the way we define and diagnose mitochondrial disease. Incorporation of changes, including the use of fibroblast growth factor 21 (FGF-21) and next generation sequencing techniques, may allow affected patients access to earlier molecular diagnosis and management. MAJOR CONCLUSIONS There have been important shifts in the diagnostic paradigm for mitochondrial disease. Diagnosis of mitochondrial disease is no longer reliant on muscle biopsy alone, but should include clinical assessment accompanied by the use of serological biomarkers and genetic analysis. Because affected patients will be defined on a molecular basis, oligosymptomatic mutation carriers should be included in the spectrum of mitochondrial disease. Use of new techniques such as the measurement of serum FGF-21 levels and next-generation-sequencing protocols should simplify the diagnosis of mitochondrial disease. GENERAL SIGNIFICANCE Improvements in the diagnostic pathway for mitochondrial disease will result in earlier, cheaper and more accurate methods to identify patients with mitochondrial disease. This article is part of a Special Issue entitled Frontiers of Mitochondrial Research.
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Affiliation(s)
- Christina Liang
- Department of Neurology, Royal North Shore Hospital, St. Leonards, New South Wales 2065, Australia
| | - Kate Ahmad
- Department of Neurology, Royal North Shore Hospital, St. Leonards, New South Wales 2065, Australia
| | - Carolyn M Sue
- Department of Neurology, Royal North Shore Hospital, St. Leonards, New South Wales 2065, Australia; Department of Neurogenetics, Kolling Institute of Medical Research, Royal North Shore Hospital and the University of Sydney, St. Leonards, New South Wales 2065, Australia.
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Augmenter of liver regeneration, a protective factor against ROS-induced oxidative damage in muscle tissue of mitochondrial myopathy affected patients. Int J Biochem Cell Biol 2013; 45:2410-9. [DOI: 10.1016/j.biocel.2013.07.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2013] [Revised: 06/24/2013] [Accepted: 07/09/2013] [Indexed: 01/21/2023]
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Mitchell JA, Waclawik AJ. Muscle Biopsy in Diagnosis of Neuromuscular Disorders: The Technical Aspects, Clinical Utility, and Recent Advances. J Histotechnol 2013. [DOI: 10.1179/his.2007.30.4.257] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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Abstract
Mitochondrial disorders are a heterogeneous group of disorders resulting from primary dysfunction of the respiratory chain. Muscle tissue is highly metabolically active, and therefore myopathy is a common element of the clinical presentation of these disorders, although this may be overshadowed by central neurological features. This review is aimed at a general medical and neurologist readership and provides a clinical approach to the recognition, investigation, and treatment of mitochondrial myopathies. Emphasis is placed on practical management considerations while including some recent updates in the field.
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Affiliation(s)
- Gerald Pfeffer
- Institute of Genetic Medicine, Newcastle University, Newcastle NE13BZ, United Kingdom
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Wagner TA, Lin CH, Tobin NH, Côté HCF, Sloan DD, Jerome KR, Frenkel LM. Quantification of mitochondrial toxicity in HIV-infected individuals by quantitative PCR compared to flow cytometry. CYTOMETRY PART B-CLINICAL CYTOMETRY 2012; 84:55-8. [PMID: 23044657 DOI: 10.1002/cyto.b.21045] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Revised: 07/25/2012] [Accepted: 08/28/2012] [Indexed: 11/09/2022]
Abstract
BACKGROUND Non-invasive diagnostic assays to evaluate mitochondrial toxicity could have significant clinical utility for HIV-infected individuals on antiretroviral therapy (ART). METHODS This study compared the ratio of mitochondrial to nuclear DNA determined by quantitative polymerase chain reaction (qPCR) to the ratio of mitochondrial to nuclear-encoded proteins by flow cytometry, in peripheral blood mononuclear cells from 73 HIV-infected individuals with and without risk factors for mitochondrial toxicity. RESULTS PCR detected similar mitochondrial/nuclear DNA in HIV-infected individuals without a history of ART, and those receiving ART with lipodystrophy, lipoatrophy, or a history of suspected lactic acidosis. However, the ratio was significantly greater in ART-untreated compared to those receiving either stavudine or didanosine. In contrast, flow cytometry did not detect any differences in mitochondrial/nuclear protein (Lin et al., Cytometry B 2009;76B:181-190). There was no correlation between the assays (rho = -0.05, P = 0.65). CONCLUSIONS Assessment of the mitochondrial/nuclear DNA ratio by qPCR performed better than the mitochondrial/nuclear-encoded protein ratio by flow cytometry to detect adverse effects of nucleoside analogs on mitochondria.
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Affiliation(s)
- Thor A Wagner
- Seattle Children's Research Institute, Seattle, Washington 98101, USA.
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Bhuvaneswar CG, Goetz JL, Stern TA. Multiple neurologic, psychiatric, and endocrine complaints in a young woman: a case discussion and review of the clinical features and management of mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke. PRIMARY CARE COMPANION TO THE JOURNAL OF CLINICAL PSYCHIATRY 2012; 10:237-44. [PMID: 18615168 DOI: 10.4088/pcc.v10n0309] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Khan A, Trevenen C, Wei XC, Sarnat HB, Payne E, Kirton A. Alpers syndrome: the natural history of a case highlighting neuroimaging, neuropathology, and fat metabolism. J Child Neurol 2012; 27:636-40. [PMID: 22114215 DOI: 10.1177/0883073811423973] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Mitochondrial diseases are increasingly being recognized as causes of encephalopathy and intractable epilepsy. There is no gold-standard test for diagnosing mitochondrial disease, and the current diagnosis relies on establishing a consistent pattern of evidence from clinical data, neuroimaging, tissue biopsy, and biochemical, genetic, and other investigations. Experience in the diagnosis and treatment of patients with certain forms of mitochondrial disease, such as Alpers syndrome, is largely gained from case reports or small case series. The authors describe a case of Alpers syndrome due to POLG1 mutations, including serial neuroimaging and pathological investigations, to illustrate two main points: (1) Unique characteristics evident on serial diffusion-weighted imaging can be a valuable indicator of Alpers syndrome; and (2) abnormal lipid metabolism can be present in Alpers syndrome, which may need to be considered when using a ketogenic diet.
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Affiliation(s)
- Aneal Khan
- Departments of Pediatrics and Medical Genetics, University of Calgary, and Alberta Children's Hospital, Calgary, Alberta, Canada.
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Sarnat HB, Flores-Sarnat L, Casey R, Scott P, Khan A. Endothelial ultrastructural alterations of intramuscular capillaries in infantile mitochondrial cytopathies: "mitochondrial angiopathy". Neuropathology 2012; 32:617-27. [PMID: 23174091 DOI: 10.1111/j.1440-1789.2012.01308.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Electron microscopy (EM) is a reliable method for diagnosing mitochondrial diseases in striated muscle biopsy in infancy. Ultrastructural alterations in mitochondria of myofibers are well documented, but there are few studies of endothelial involvement in intramuscular capillaries. Quadriceps femoris biopsies of five representative infants and toddlers, ages neonate to 3.5 years, were performed because of clinical and laboratory data consistent with mitochondrial disease without mitochondrial DNA (mtDNA) mutations and likely with nuclear DNA mutations. Pathological studies included histochemistry, EM, respiratory chain enzymatic assay and mtDNA sequencing and deletion/duplication analysis. EM demonstrated frequent and severe alterations of mitochondria in capillary endothelium. The most constant changes included: either too few or fragmented cristae; stacked and whorled cristae; paracrystallin structures that often were large and spheroid with stress fractures; closely apposed membranes of granular endoplasmic reticulum surrounding mitochondria with loss of the normal intervening layer of cytoplasm; long narrow, thin looped microvilli extending into the lumen; and thick microvilli containing large, abnormal mitochondria. We conclude that mitochondrial cytopathies in early life exhibit more severe ultrastructural alterations in the endothelium than in myofibers and that paracrystallin body structure differs, perhaps due to less rigid surrounding structures. This distribution may explain the frequent lack of prominent histochemical and biochemical abnormalities in muscle biopsies of young patients. Endothelial changes do not distinguish the genetic defects. Vascular involvement in brain contributes to cerebral lesions and neuronal death by impairment of molecular and nutrient transport and ischemia; endothelium in muscle may reflect similar changes.
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Affiliation(s)
- Harvey B Sarnat
- Department of Paediatrics, University of Calgary Faculty of Medicine and Alberta Children's Hospital, University of Alberta, Edmonton, Alberta, Canada.
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Mice deleted for heart-type cytochrome c oxidase subunit 7a1 develop dilated cardiomyopathy. Mitochondrion 2011; 12:294-304. [PMID: 22119795 DOI: 10.1016/j.mito.2011.11.002] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Revised: 11/07/2011] [Accepted: 11/11/2011] [Indexed: 12/26/2022]
Abstract
Subunit 7a of mouse cytochrome c oxidase (Cox) displays a contractile muscle-specific isoform, Cox7a1, that is the major cardiac form. To gain insight into the role of this isoform, we have produced a new knockout mouse line that lacks Cox7a1. We show that homozygous and heterozygous Cox7a1 knockout mice, although viable, have reduced Cox activity and develop a dilated cardiomyopathy at 6 weeks of age. Surprisingly, the cardiomyopathy improves and stabilizes by 6 months of age. Cox7a1 knockout mice incorporate more of the "liver-type" isoform Cox7a2 into the cardiac Cox holoenzyme and, also surprisingly, have higher tissue ATP levels.
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Sundaram C, Meena AK, Uppin MS, Govindaraj P, Vanniarajan A, Thangaraj K, Kaul S, Kekunnaya R, Murthy JMK. Contribution of muscle biopsy and genetics to the diagnosis of chronic progressive external opthalmoplegia of mitochondrial origin. J Clin Neurosci 2011; 18:535-8. [PMID: 21277779 DOI: 10.1016/j.jocn.2010.06.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2010] [Revised: 06/07/2010] [Accepted: 06/14/2010] [Indexed: 11/18/2022]
Abstract
Chronic progressive external opthalmoplegia (CPEO) is the most common phenotypic syndrome of the mitochondrial myopathies. Muscle biopsy, which provides important morphological clues for the diagnosis of mitochondrial disorders, is normal in approximately 25% of patients with CPEO, thus necessitating molecular genetic analysis for more accurate diagnosis. We aimed to study the utility of various histochemical stains in the diagnosis of CPEO on muscle biopsy and to correlate these results with genetic studies. Between May 2005 and November 2007 all 45 patients diagnosed with CPEO were included in the study (23 males; mean age at presentation, 35 years). Thirty-nine patients had CPEO only and six had CPEO plus; two had a positive family history but the remaining 39 patients had sporadic CPEO. Muscle biopsy samples were stained with hematoxylin and eosin, modified Gomori's trichrome stain, succinic dehydrogenase (SDH), cytochrome C oxidase (COX) and combined COX-SDH. Ragged red fibers were seen in 27 biopsies; seven showed characteristics of neurogenic atrophy only, and 11 were normal. The abnormal fibers were best identified on COX-SDH stain. A complete mitochondrial genome was amplified in muscle and blood samples of all patients. Mutations were found in transfer RNA, ribosomal RNA, ND, CYTB, COX I, II and III genes. Mitochondrial gene mutations were found in ten of the 11 patients with a normal muscle biopsy. The genetic mutations were classified according to their significance. The observed muscle biopsy findings were correlated with genetic mutations noted. Histological studies should be combined with genetic studies for the definitive diagnosis of CPEO syndrome.
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Affiliation(s)
- Challa Sundaram
- Department of Pathology, Nizam's Institute Medical Sciences, Punjagutta, Hyderabad 500082, Andhra Pradesh, India.
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Successful left hemihepatectomy and perioperative management of a patient with biliary cystadenocarcinoma, complicated with MELAS syndrome: report of a case. Surg Today 2010; 40:878-82. [PMID: 20740354 DOI: 10.1007/s00595-009-4145-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2009] [Accepted: 07/01/2009] [Indexed: 10/19/2022]
Abstract
Mitochondrial Myopathy, Encephalopathy, Lactic Acidosis, and Stroke-like syndrome (MELAS) is a rare, fetal disease caused by a mutation in mitochondrial DNA that leads to impaired oxidative metabolism in skeletal muscle, the central nervous system, and liver function. This report presents the case of a 50-year-old woman with biliary cystadenocarcinoma complicated by MELAS who underwent a successful left hemihepatectomy. In this case, the diagnostic key for the malignant tumor was an (18)F-fluorodeoxyglucose positron emission tomography study, which was useful even in a patient with MELAS, which causes abnormal glucose metabolism. The perioperative management of such patients includes special precautions to prevent lactic acidosis and deterioration of the reserved liver function after a hepatectomy, since the mitochondrial function in MELAS patients is abnormal. The patient in this report has remained free of liver dysfunctions and cancer recurrence for 2 years following the hepatectomy. This is the first report of a successful major hepatectomy for a patient with MELAS.
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Malik SG, Irwanto KA, Ostrow JD, Tiribelli C. Effect of bilirubin on cytochrome c oxidase activity of mitochondria from mouse brain and liver. BMC Res Notes 2010; 3:162. [PMID: 20534120 PMCID: PMC2901210 DOI: 10.1186/1756-0500-3-162] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2010] [Accepted: 06/09/2010] [Indexed: 12/04/2022] Open
Abstract
Background The unbound, free concentration (Bf) of unconjugated bilirubin (UCB), and not the total UCB level, has been shown to correlate with bilirubin cytotoxicity, but the key molecular mechanisms accounting for the toxic effects of UCB are largely unknown. Findings Mouse liver mitochondria increase unbound UCB oxidation, consequently increasing the apparent rate constant for unbound UCB oxidation by HRP (Kp), higher than in control and mouse brain mitochondria, emphasizing the importance of determining Kp in complete systems containing the organelles being studied. The in vitro effects of UCB on cytochrome c oxidase activity in mitochondria isolated from mouse brain and liver were studied at Bf ranging from 22 to 150 nM. The results show that UCB at Bf up to 60 nM did not alter mitochondrial cytochrome c oxidase activity, while the higher concentrations significantly inhibited the enzyme activity by 20% in both liver and brain mitochondria. Conclusions We conclude that it is essential to include the organelles being studied in the medium used in measuring both Kp and Bf. A moderately elevated, pathophysiologically-relevant Bf impaired the cytochrome c oxidase activity modestly in mitochondria from mouse brain and liver.
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Affiliation(s)
- Safarina G Malik
- Eijkman Institute for Molecular Biology, Jl, Diponegoro 69, Jakarta 10430, Indonesia.
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Gao J, Shen M, Guo X, Li X, Li J. Proteomic Mechanism of Myocardial Angiogenesis Augmented by Remote Ischemic Training of Skeletal Muscle in Rabbit. Cardiovasc Ther 2010; 29:199-210. [DOI: 10.1111/j.1755-5922.2009.00097.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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Venkatesh S, Ramachandran A, Zachariah A, Oommen A. Mitochondrial ATP synthase inhibition and nitric oxide are involved in muscle weakness that occurs in acute exposure of rats to monocrotophos. Toxicol Mech Methods 2010; 19:239-45. [PMID: 19730754 PMCID: PMC2736536 DOI: 10.1080/15376510802455354] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Organophosphate poisoning in the context of self-harm is a common medical emergency in Asia. Prolonged muscle weakness is an important but poorly understood cause of morbidity and mortality of the poisoning. This study examined mitochondrial function and its modulation by nitric oxide in muscle weakness of rats exposed to an acute, oral (0.8LD(50)) dose of monocrotophos. Muscle mitochondrial ATP synthase activity was inhibited in the rat in acute exposure to monocrotophos while respiration per se was not affected. This was accompanied by decreased mitochondrial uptake of calcium and increased levels of nitric oxide. Reactive cysteine groups of ATP synthase subunits were reduced in number, which may contribute to decreased enzyme activity. The decrease in ATP synthase activity and reactive cysteine groups of ATP synthase subunits was prevented by treatment of animals with the nitric oxide synthase inhibitor, L-N(G) Nitroarginine methyl ester, at 12 mg/kg body weight for 9 days in drinking water, prior to monocrotophos exposure. This indicated a role for nitric oxide in the process. The alterations in mitochondrial calcium uptake may influence cytosolic calcium levels and contribute to muscle weakness of acute organophosphate exposure.
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Affiliation(s)
- S Venkatesh
- Department of Neurological Sciences, Christian Medical College, Vellore, India
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Abstract
PURPOSE OF REVIEW The purpose of this review is to discuss the role of muscle biopsy in the current age of genetic testing. RECENT FINDINGS The diagnostic approach to patients with suspected genetically determined myopathies has been altered by recent advances in molecular diagnostic technologies and by the increased number of conditions for which the genetic alterations have been identified. Myopathological aspects can narrow down the differential diagnosis when the clinical phenotype is not informative enough and can help guide the molecular investigation. SUMMARY Here, we review genetic and myopathological aspects of selected genetically determined myopathies.
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Prasad AN, Malinger G, Lerman-Sagie T. Primary disorders of metabolism and disturbed fetal brain development. Clin Perinatol 2009; 36:621-38. [PMID: 19732617 DOI: 10.1016/j.clp.2009.06.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
There exists a link between the in utero metabolic environment and the development of the fetal nervous system. Prenatal neurosonography offers a unique, noninvasive tool in the detection of developmental brain malformations and the ability to monitor changes over time. This article explores the association of malformations of cerebral development reported in association with inborn errors of metabolism, and speculates on potential mechanisms by which such malformations arise. The detection of cerebral malformations prenatally should lead to a search for both genetic etiologies and inborn errors of metabolism in the fetus. Improving the changes of an early diagnosis provides for timely therapeutic interventions and it is hoped a brighter future for affected children and their families.
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Affiliation(s)
- Asuri N Prasad
- Section of Clinical Neurosciences, Department of Pediatrics and Child Health, Children's Hospital of Western Ontario, London Health Sciences Centre, University of Western Ontario, B-509, 800 Commissioners Road East, London, Ontario, N6C4G5, Canada
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Finsterer J. Manifestations of the mitochondrial A3243G mutation. Int J Cardiol 2009; 137:60-2. [DOI: 10.1016/j.ijcard.2008.04.089] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2008] [Accepted: 04/26/2008] [Indexed: 11/27/2022]
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Yuri T, Kondo Y, Kohno K, Lei YC, Kanematsu S, Kuwata M, Iwasaka T, Tsubura A. An autopsy case of chronic progressive external ophthalmoplegia with renal insufficiency. Med Mol Morphol 2008; 41:233-7. [PMID: 19107614 DOI: 10.1007/s00795-008-0420-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2008] [Accepted: 09/17/2008] [Indexed: 01/08/2023]
Abstract
An autopsy of a 44-year-old Japanese woman with mitochondrial cytopathy confirmed the presence of chronic progressive external ophthalmoplegia (CPEO). Immunohistochemistry using antimitochondrial antibody was performed to observe the ultrastructure of the skeletal muscle and renal tissues. The patient was born of consanguineous parents, developed normally, and was of average intelligence. At 22 years of age, the patient noticed hearing loss, and subsequently, over time, developed a progressive generalized muscle weakness, which included limitation of eye movement and ptosis. At age 41, a muscle biopsy was performed using the modified Gomori trichrome method and demonstrated the presence of ragged red fibers. After the evaluation of her results in conjunction with her clinical course, she was diagnosed with CPEO. Renal insufficiency was discovered at age 30, and the patient died at the age of 44 of respiratory failure caused by respiratory muscle weakness and pneumonia. The autopsy revealed fiber size variation within the skeletal muscle, and an antimitochondrial antibody analysis demonstrated the accumulation of mitochondria between the bundles of myofibrils, as well as in subsarcolemmal locations. Ultrastructurally, abnormal mitochondria with disoriented cristae and paracrystalline inclusions were seen. Although no remarkable histological changes were noted in the kidneys, tubular epithelial cells exhibited accumulated abnormal mitochondria, similar to those seen in the skeletal muscle. Because mitochondrial diseases can affect other energy-dependent organs in addition to the skeletal muscle, immunohistochemical examinations employing an antimitochondrial antibody are useful for obtaining further ultrastructural observations that can assist in making a distinct diagnosis of this systemic disorder.
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Affiliation(s)
- Takashi Yuri
- Department of Pathology II, Kansai Medical University, Moriguchi, Osaka, 570-8506, Japan.
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Serial protein labeling with infrared maleimide dyes to identify cysteine modifications. J Proteomics 2008; 71:222-30. [DOI: 10.1016/j.jprot.2008.04.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2008] [Revised: 04/17/2008] [Accepted: 04/25/2008] [Indexed: 12/16/2022]
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Prasad AN, Bunzeluk K, Prasad C, Chodirker BN, Magnus KG, Greenberg CR. Agenesis of the corpus callosum and cerebral anomalies in inborn errors of metabolism. Congenit Anom (Kyoto) 2007; 47:125-35. [PMID: 17988254 DOI: 10.1111/j.1741-4520.2007.00160.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Dysgenesis of the corpus callosum has been recognized as a marker for aberrant development of the central nervous system. It has been suggested that developmental defects of the corpus callosum may be more frequently encountered in patients with inborn errors of metabolism. The objectives of the present study were to determine the prevalence of developmental defects of the corpus callosum in patients attending a genetics-metabolic disorders clinic, to describe the spectrum of abnormalities in brain development in patients with confirmed inborn errors of metabolism and abnormalities of the corpus callosum as ascertained by neuroimaging and/or postmortem studies. Nineteen patients (10 males, 9 females) with confirmed metabolic diagnoses were identified by systematic search of the genetics clinic database. All 19 (100%) expressed variable degrees of hypoplasia, complete or partial agenesis (ACC). Abnormalities of head size were noted in 17/19 (89.5%). The majority 12/17 (70.5%) were associated with microcephaly, while macrocrania was noted in 5/17 (29.5%). Associated central nervous system (CNS) anomalies included abnormalities in ventricular morphology in 18/19 (94.7%), ventriculomegaly in 11/19 (63.1%), increased extraxial cerebrospinal fluid space in 11/19 (57.9%), changes in the gray matter (neuronal migration defects, porencephaly) in 9/19 (47.3%), white matter changes in 12/19 (63.1%) and abnormalities of the posterior fossa and hindbrain in 12/19 (63.1%). In patients with inborn errors of metabolism, dysgenesis of the corpus callosum serves as a marker for other developmental defects within the nervous system. We discuss here potential mechanisms by which metabolic defects affect diverse biochemical pathways, altering key neurobiological processes (e.g. defective cell membrane formation, cellular bioenergetics and cell-to-cell signaling), that eventually lead to structural abnormalities in the developing nervous system.
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Affiliation(s)
- Asuri N Prasad
- Section of Clinical Neurosciences, Department of Pediatrics and Child Health, Unviersity of Western Ontario, London, ON, Canada.
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Diomedi-Camassei F, Di Giandomenico S, Santorelli FM, Caridi G, Piemonte F, Montini G, Ghiggeri GM, Murer L, Barisoni L, Pastore A, Muda AO, Valente ML, Bertini E, Emma F. COQ2 nephropathy: a newly described inherited mitochondriopathy with primary renal involvement. J Am Soc Nephrol 2007; 18:2773-80. [PMID: 17855635 DOI: 10.1681/asn.2006080833] [Citation(s) in RCA: 248] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Primary coenzyme Q(10) (CoQ(10)) deficiency includes a group of rare autosomal recessive disorders primarily characterized by neurological and muscular symptoms. Rarely, glomerular involvement has been reported. The COQ2 gene encodes the para-hydroxybenzoate-polyprenyl-transferase enzyme of the CoQ(10) synthesis pathway. We identified two patients with early-onset glomerular lesions that harbored mutations in the COQ2 gene. The first patient presented with steroid-resistant nephrotic syndrome at the age of 18 months as a result of collapsing glomerulopathy, with no extrarenal symptoms. The second patient presented at five days of life with oliguria, had severe extracapillary proliferation on renal biopsy, rapidly developed end-stage renal disease, and died at the age of 6 months after a course complicated by progressive epileptic encephalopathy. Ultrastructural examination of renal specimens from these cases, as well as from two previously reported patients, showed an increased number of dysmorphic mitochondria in glomerular cells. Biochemical analyses demonstrated decreased activities of respiratory chain complexes [II+III] and decreased CoQ(10) concentrations in skeletal muscle and renal cortex. In conclusion, we suggest that inherited COQ2 mutations cause a primary glomerular disease with renal lesions that vary in severity and are not necessarily associated with neurological signs. COQ2 nephropathy should be suspected when electron microscopy shows an increased number of abnormal mitochondria in podocytes and other glomerular cells.
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Affiliation(s)
- Francesca Diomedi-Camassei
- Divisions of Pathology , Department of Laboratory Medicine, Bambino Gesù Children's Hospital and Research Institute, Rome, Italy
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Filosto M, Tomelleri G, Tonin P, Scarpelli M, Vattemi G, Rizzuto N, Padovani A, Simonati A. Neuropathology of mitochondrial diseases. Biosci Rep 2007; 27:23-30. [PMID: 17541738 DOI: 10.1007/s10540-007-9034-3] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
The term "mitochondrial diseases" (MD) refers to a group of disorders related to respiratory chain dysfunction. Clinical features are usually extremely heterogeneous because MD may involve several tissues with different degrees of severity. Muscle and brain are mostly affected, probably because of their high dependence on oxidative metabolism. Muscle can be the only affected tissue or involved as a part of a multi-system disease; ragged red fibers, accumulation of structurally altered mitochondria and cytochrome-c-oxidase (COX) negative fibers are the main pathological features. In mitochondrial encephalopathies, central nervous system (CNS) structures are affected according to different patterns of distribution and severity. Characteristic lesions are neuronal loss, vasculo-necrotic changes, gliosis, demyelination and spongy degeneration. In accordance with either grey matter or white matter involvement two main groups of diseases may be distinguished. Neuronal loss and vasculo-necrotic multifocal lesions are the common features of grey matter involvement; demyelination and spongy degeneration occur when white matter is affected, often associated with less severe lesions of the grey structures. Grey matter lesions are prevalent in MERRF, MELAS, Alpers and Leigh syndromes. White matter involvement is always seen in Kearns-Sayre syndrome and was recently described in mtDNA depletion syndrome linked to dGK mutations and in the rare conditions associated with complex I and II deficiency. In this review we describe the main histopathological features of muscle and CNS lesions in mitochondrial diseases.
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Affiliation(s)
- Massimiliano Filosto
- Clinical Neurology, Section for Neuromuscular Diseases and Neuropathies, University Hospital Spedali Civili, P.le Spedali Civili 1, 25100, Brescia, Italy.
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