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Galli RA, Borsboom TC, Gineste C, Brocca L, Rossi M, Hwee DT, Malik FI, Bottinelli R, Gondin J, Pellegrino MA, de Winter JM, Ottenheijm CA. Tirasemtiv enhances submaximal muscle tension in an Acta1:p.Asp286Gly mouse model of nemaline myopathy. J Gen Physiol 2024; 156:e202313471. [PMID: 38376469 PMCID: PMC10876480 DOI: 10.1085/jgp.202313471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 12/01/2023] [Accepted: 01/30/2024] [Indexed: 02/21/2024] Open
Abstract
Nemaline myopathies are the most common form of congenital myopathies. Variants in ACTA1 (NEM3) comprise 15-25% of all nemaline myopathy cases. Patients harboring variants in ACTA1 present with a heterogeneous disease course characterized by stable or progressive muscle weakness and, in severe cases, respiratory failure and death. To date, no specific treatments are available. Since NEM3 is an actin-based thin filament disease, we tested the ability of tirasemtiv, a fast skeletal muscle troponin activator, to improve skeletal muscle function in a mouse model of NEM3, harboring the patient-based p.Asp286Gly variant in Acta1. Acute and long-term tirasemtiv treatment significantly increased muscle contractile capacity at submaximal stimulation frequencies in both fast-twitch extensor digitorum longus and gastrocnemius muscle, and intermediate-twitch diaphragm muscle in vitro and in vivo. Additionally, long-term tirasemtiv treatment in NEM3 mice resulted in a decreased respiratory rate with preserved minute volume, suggesting more efficient respiration. Altogether, our data support the therapeutic potential of fast skeletal muscle troponin activators in alleviating skeletal muscle weakness in a mouse model of NEM3 caused by the Acta1:p.Asp286Gly variant.
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Affiliation(s)
- Ricardo A. Galli
- Amsterdam UMC Location Vrije Universiteit Amsterdam, Physiology, Amsterdam, The Netherlands
- Amsterdam Movement Sciences, Musculoskeletal Health and Tissue Function and Regeneration, Amsterdam, The Netherlands
| | - Tamara C. Borsboom
- Amsterdam UMC Location Vrije Universiteit Amsterdam, Physiology, Amsterdam, The Netherlands
| | | | - Lorenza Brocca
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Maira Rossi
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Darren T. Hwee
- Research and Early Development, Cytokinetics Inc., South San Francisco, CA, USA
| | - Fady I. Malik
- Research and Early Development, Cytokinetics Inc., South San Francisco, CA, USA
| | - Roberto Bottinelli
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
- IRCCS Mondino Foundation, Pavia, Italy
| | - Julien Gondin
- Aix-Marseille University, CNRS, CRMBM, Marseille, France
- Institut NeuroMyoGène, Unité Physiopathologie et Génétique du Neurone et du Muscle, Université Claude Bernard Lyon 1, CNRS UMR 5261, INSERM U1315, Université Lyon, Lyon, France
| | | | - Josine M. de Winter
- Amsterdam UMC Location Vrije Universiteit Amsterdam, Physiology, Amsterdam, The Netherlands
- Amsterdam Movement Sciences, Musculoskeletal Health and Tissue Function and Regeneration, Amsterdam, The Netherlands
- Amsterdam Cardiovascular Sciences, Heart Failure and Arrhythmias, Amsterdam, The Netherlands
| | - Coen A.C. Ottenheijm
- Amsterdam UMC Location Vrije Universiteit Amsterdam, Physiology, Amsterdam, The Netherlands
- Amsterdam Cardiovascular Sciences, Pulmonary Hypertension and Atherosclerosis, Amsterdam, The Netherlands
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ, USA
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2
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Nguyen MT, Dash R, Jeong K, Lee W. Role of Actin-Binding Proteins in Skeletal Myogenesis. Cells 2023; 12:2523. [PMID: 37947600 PMCID: PMC10650911 DOI: 10.3390/cells12212523] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 10/22/2023] [Accepted: 10/23/2023] [Indexed: 11/12/2023] Open
Abstract
Maintenance of skeletal muscle quantity and quality is essential to ensure various vital functions of the body. Muscle homeostasis is regulated by multiple cytoskeletal proteins and myogenic transcriptional programs responding to endogenous and exogenous signals influencing cell structure and function. Since actin is an essential component in cytoskeleton dynamics, actin-binding proteins (ABPs) have been recognized as crucial players in skeletal muscle health and diseases. Hence, dysregulation of ABPs leads to muscle atrophy characterized by loss of mass, strength, quality, and capacity for regeneration. This comprehensive review summarizes the recent studies that have unveiled the role of ABPs in actin cytoskeletal dynamics, with a particular focus on skeletal myogenesis and diseases. This provides insight into the molecular mechanisms that regulate skeletal myogenesis via ABPs as well as research avenues to identify potential therapeutic targets. Moreover, this review explores the implications of non-coding RNAs (ncRNAs) targeting ABPs in skeletal myogenesis and disorders based on recent achievements in ncRNA research. The studies presented here will enhance our understanding of the functional significance of ABPs and mechanotransduction-derived myogenic regulatory mechanisms. Furthermore, revealing how ncRNAs regulate ABPs will allow diverse therapeutic approaches for skeletal muscle disorders to be developed.
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Affiliation(s)
- Mai Thi Nguyen
- Department of Biochemistry, Dongguk University College of Medicine, 123 Dongdae-ro, Gyeongju 38066, Republic of Korea; (M.T.N.); (K.J.)
| | - Raju Dash
- Department of Anatomy, Dongguk University College of Medicine, 123 Dongdae-ro, Gyeongju 38066, Republic of Korea;
- Department of New Biology, Daegu Gyeongbuk Institute of Science & Technology (DGIST), Daegu 42988, Republic of Korea
| | - Kyuho Jeong
- Department of Biochemistry, Dongguk University College of Medicine, 123 Dongdae-ro, Gyeongju 38066, Republic of Korea; (M.T.N.); (K.J.)
| | - Wan Lee
- Department of Biochemistry, Dongguk University College of Medicine, 123 Dongdae-ro, Gyeongju 38066, Republic of Korea; (M.T.N.); (K.J.)
- Channelopathy Research Center, Dongguk University College of Medicine, 32 Dongguk-ro, Ilsan Dong-gu, Goyang 10326, Republic of Korea
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3
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De La Vega FM, Chowdhury S, Moore B, Frise E, McCarthy J, Hernandez EJ, Wong T, James K, Guidugli L, Agrawal PB, Genetti CA, Brownstein CA, Beggs AH, Löscher BS, Franke A, Boone B, Levy SE, Õunap K, Pajusalu S, Huentelman M, Ramsey K, Naymik M, Narayanan V, Veeraraghavan N, Billings P, Reese MG, Yandell M, Kingsmore SF. Artificial intelligence enables comprehensive genome interpretation and nomination of candidate diagnoses for rare genetic diseases. Genome Med 2021; 13:153. [PMID: 34645491 PMCID: PMC8515723 DOI: 10.1186/s13073-021-00965-0] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 08/27/2021] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Clinical interpretation of genetic variants in the context of the patient's phenotype is becoming the largest component of cost and time expenditure for genome-based diagnosis of rare genetic diseases. Artificial intelligence (AI) holds promise to greatly simplify and speed genome interpretation by integrating predictive methods with the growing knowledge of genetic disease. Here we assess the diagnostic performance of Fabric GEM, a new, AI-based, clinical decision support tool for expediting genome interpretation. METHODS We benchmarked GEM in a retrospective cohort of 119 probands, mostly NICU infants, diagnosed with rare genetic diseases, who received whole-genome or whole-exome sequencing (WGS, WES). We replicated our analyses in a separate cohort of 60 cases collected from five academic medical centers. For comparison, we also analyzed these cases with current state-of-the-art variant prioritization tools. Included in the comparisons were trio, duo, and singleton cases. Variants underpinning diagnoses spanned diverse modes of inheritance and types, including structural variants (SVs). Patient phenotypes were extracted from clinical notes by two means: manually and using an automated clinical natural language processing (CNLP) tool. Finally, 14 previously unsolved cases were reanalyzed. RESULTS GEM ranked over 90% of the causal genes among the top or second candidate and prioritized for review a median of 3 candidate genes per case, using either manually curated or CNLP-derived phenotype descriptions. Ranking of trios and duos was unchanged when analyzed as singletons. In 17 of 20 cases with diagnostic SVs, GEM identified the causal SVs as the top candidate and in 19/20 within the top five, irrespective of whether SV calls were provided or inferred ab initio by GEM using its own internal SV detection algorithm. GEM showed similar performance in absence of parental genotypes. Analysis of 14 previously unsolved cases resulted in a novel finding for one case, candidates ultimately not advanced upon manual review for 3 cases, and no new findings for 10 cases. CONCLUSIONS GEM enabled diagnostic interpretation inclusive of all variant types through automated nomination of a very short list of candidate genes and disorders for final review and reporting. In combination with deep phenotyping by CNLP, GEM enables substantial automation of genetic disease diagnosis, potentially decreasing cost and expediting case review.
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Affiliation(s)
- Francisco M. De La Vega
- Fabric Genomics Inc., Oakland, CA USA
- Department of Biomedical Data Science, Stanford University School of Medicine, Stanford, CA USA
- Current Address: Tempus Labs Inc., Redwood City, CA 94065 USA
| | - Shimul Chowdhury
- Rady Children’s Institute for Genomic Medicine, San Diego, CA USA
| | - Barry Moore
- Department of Human Genetics, Utah Center for Genetic Discovery, University of Utah, Salt Lake City, UT USA
| | | | | | - Edgar Javier Hernandez
- Department of Human Genetics, Utah Center for Genetic Discovery, University of Utah, Salt Lake City, UT USA
| | - Terence Wong
- Rady Children’s Institute for Genomic Medicine, San Diego, CA USA
| | - Kiely James
- Rady Children’s Institute for Genomic Medicine, San Diego, CA USA
| | - Lucia Guidugli
- Rady Children’s Institute for Genomic Medicine, San Diego, CA USA
| | - Pankaj B. Agrawal
- Division of Genetics and Genomics, The Manton Center for Orphan Disease Research, Boston Children’s Hospital, Harvard Medical School, Boston, MA USA
- Division of Newborn Medicine, Boston Children’s Hospital, Boston, MA USA
| | - Casie A. Genetti
- Division of Genetics and Genomics, The Manton Center for Orphan Disease Research, Boston Children’s Hospital, Harvard Medical School, Boston, MA USA
| | - Catherine A. Brownstein
- Division of Genetics and Genomics, The Manton Center for Orphan Disease Research, Boston Children’s Hospital, Harvard Medical School, Boston, MA USA
| | - Alan H. Beggs
- Division of Genetics and Genomics, The Manton Center for Orphan Disease Research, Boston Children’s Hospital, Harvard Medical School, Boston, MA USA
| | - Britt-Sabina Löscher
- Institute of Clinical Molecular Biology, Christian-Albrechts-University of Kiel & University Hospital Schleswig-Holstein, Kiel, Germany
| | - Andre Franke
- Institute of Clinical Molecular Biology, Christian-Albrechts-University of Kiel & University Hospital Schleswig-Holstein, Kiel, Germany
| | - Braden Boone
- HudsonAlpha Institute for Biotechnology, Huntsville, AL USA
| | - Shawn E. Levy
- HudsonAlpha Institute for Biotechnology, Huntsville, AL USA
| | - Katrin Õunap
- Department of Clinical Genetics, United Laboratories, Tartu University Hospital, Tartu, Estonia
- Department of Clinical Genetics, Institute of Clinical Medicine, University of Tartu, Tartu, Estonia
| | - Sander Pajusalu
- Department of Clinical Genetics, United Laboratories, Tartu University Hospital, Tartu, Estonia
- Department of Clinical Genetics, Institute of Clinical Medicine, University of Tartu, Tartu, Estonia
| | - Matt Huentelman
- Center for Rare Childhood Disorders, Translational Genomics Research Institute, Phoenix, AZ USA
| | - Keri Ramsey
- Center for Rare Childhood Disorders, Translational Genomics Research Institute, Phoenix, AZ USA
| | - Marcus Naymik
- Center for Rare Childhood Disorders, Translational Genomics Research Institute, Phoenix, AZ USA
| | - Vinodh Narayanan
- Center for Rare Childhood Disorders, Translational Genomics Research Institute, Phoenix, AZ USA
| | | | | | | | - Mark Yandell
- Fabric Genomics Inc., Oakland, CA USA
- Department of Human Genetics, Utah Center for Genetic Discovery, University of Utah, Salt Lake City, UT USA
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4
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Laflamme N, Lace B, Thonta Setty S, Rioux N, Labrie Y, Droit A, Chrestian N, Rivest S. A Homozygous Deep Intronic Mutation Alters the Splicing of Nebulin Gene in a Patient With Nemaline Myopathy. Front Neurol 2021; 12:660113. [PMID: 34211429 PMCID: PMC8239344 DOI: 10.3389/fneur.2021.660113] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 05/11/2021] [Indexed: 11/19/2022] Open
Abstract
Nemaline myopathy is a rare disorder affecting the muscle sarcomere. Mutations in nebulin gene (NEB) are known to be responsible for about 50% of nemaline myopathy cases. Nebulin is a giant protein which is formed integrally with the sarcomeric thin filament. This complex gene is under extensive alternative splicing giving rise to multiple isoforms. In this study, we report a 6-year-old boy presenting with general muscular weaknesses. Identification of rod-shaped structures in the patient' biopsy raised doubt about the presence of a nemaline myopathy. Next-generation sequencing was used to identify a causative mutation for the patient syndrome. A homozygous deep intronic substitution was found in the intron 144 of the NEB. The variant was predicted by in silico tools to create a new donor splice site. Molecular analysis has shown that the mutation could alter splicing events of the nebulin gene leading to a significant decrease of isoforms level. This change in the expression level of nebulin could give rise to functional consequences in the sarcomere. These results are consistent with the phenotypes observed in the patient. Such a discovery of variants in this gene will allow a better understanding of the involvement of nebulin in neuromuscular diseases and help find new treatments for the nemaline myopathy.
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Affiliation(s)
- Nathalie Laflamme
- Centre de recherche CHU de Québec- Laval University, Quebec City, QC, Canada
| | - Baiba Lace
- Department of Medical Genetics, Centre Mère Enfant Soleil, Laval University, Quebec City, QC, Canada
| | | | - Nadie Rioux
- Centre de recherche CHU de Québec- Laval University, Quebec City, QC, Canada
| | - Yvan Labrie
- Centre de recherche CHU de Québec- Laval University, Quebec City, QC, Canada
| | - Arnaud Droit
- Centre de recherche CHU de Québec- Laval University, Quebec City, QC, Canada
| | - Nicolas Chrestian
- Department of Pediatric Neurology, Pediatric Neuromuscular Disorder, Centre Mère Enfant Soleil, Laval University, Quebec City, QC, Canada
| | - Serge Rivest
- Centre de recherche CHU de Québec- Laval University, Quebec City, QC, Canada
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5
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van de Locht M, Donkervoort S, de Winter JM, Conijn S, Begthel L, Kusters B, Mohassel P, Hu Y, Medne L, Quinn C, Moore SA, Foley AR, Seo G, Hwee DT, Malik FI, Irving T, Ma W, Granzier HL, Kamsteeg EJ, Immadisetty K, Kekenes-Huskey P, Pinto JR, Voermans N, Bönnemann CG, Ottenheijm CA. Pathogenic variants in TNNC2 cause congenital myopathy due to an impaired force response to calcium. J Clin Invest 2021; 131:145700. [PMID: 33755597 DOI: 10.1172/jci145700] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 03/18/2021] [Indexed: 12/11/2022] Open
Abstract
Troponin C (TnC) is a critical regulator of skeletal muscle contraction; it binds Ca2+ to activate muscle contraction. Surprisingly, the gene encoding fast skeletal TnC (TNNC2) has not yet been implicated in muscle disease. Here, we report 2 families with pathogenic variants in TNNC2. Patients present with a distinct, dominantly inherited congenital muscle disease. Molecular dynamics simulations suggested that the pathomechanisms by which the variants cause muscle disease include disruption of the binding sites for Ca2+ and for troponin I. In line with these findings, physiological studies in myofibers isolated from patients' biopsies revealed a markedly reduced force response of the sarcomeres to [Ca2+]. This pathomechanism was further confirmed in experiments in which contractile dysfunction was evoked by replacing TnC in myofibers from healthy control subjects with recombinant, mutant TnC. Conversely, the contractile dysfunction of myofibers from patients was repaired by replacing endogenous, mutant TnC with recombinant, wild-type TnC. Finally, we tested the therapeutic potential of the fast skeletal muscle troponin activator tirasemtiv in patients' myofibers and showed that the contractile dysfunction was repaired. Thus, our data reveal that pathogenic variants in TNNC2 cause congenital muscle disease, and they provide therapeutic angles to repair muscle contractility.
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Affiliation(s)
- Martijn van de Locht
- Deptartment of Physiology, Amsterdam UMC (location VUmc), Amsterdam, Netherlands
| | - Sandra Donkervoort
- Neuromuscular and Neurogenetic Disorders of Childhood Section, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland, USA
| | - Josine M de Winter
- Deptartment of Physiology, Amsterdam UMC (location VUmc), Amsterdam, Netherlands
| | - Stefan Conijn
- Deptartment of Physiology, Amsterdam UMC (location VUmc), Amsterdam, Netherlands
| | - Leon Begthel
- Deptartment of Physiology, Amsterdam UMC (location VUmc), Amsterdam, Netherlands
| | - Benno Kusters
- Department of Neurology and Human Genetics, Radboud University Medical Center, Nijmegen, Netherlands
| | - Payam Mohassel
- Neuromuscular and Neurogenetic Disorders of Childhood Section, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland, USA
| | - Ying Hu
- Neuromuscular and Neurogenetic Disorders of Childhood Section, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland, USA
| | - Livija Medne
- Division of Human Genetics, Department of Pediatrics, Individualized Medical Genetics Center, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Colin Quinn
- Department of Neurology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Steven A Moore
- Department of Pathology, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - A Reghan Foley
- Neuromuscular and Neurogenetic Disorders of Childhood Section, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland, USA
| | - Gwimoon Seo
- Protein Expression Facility, Institute of Molecular Biophysics, The Florida State University, Tallahassee, Florida, USA
| | - Darren T Hwee
- Research and Early Development, Cytokinetics Inc., South San Francisco, California, USA
| | - Fady I Malik
- Research and Early Development, Cytokinetics Inc., South San Francisco, California, USA
| | - Thomas Irving
- BioCAT, Illinois Institute of Technology, Chicago, Illinois, USA
| | - Weikang Ma
- BioCAT, Illinois Institute of Technology, Chicago, Illinois, USA
| | - Henk L Granzier
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, Arizona, USA
| | - Erik-Jan Kamsteeg
- Department of Neurology and Human Genetics, Radboud University Medical Center, Nijmegen, Netherlands
| | - Kalyan Immadisetty
- Department of Cell and Molecular Physiology, Loyola University, Chicago, Illinois, USA
| | - Peter Kekenes-Huskey
- Department of Cell and Molecular Physiology, Loyola University, Chicago, Illinois, USA
| | - José R Pinto
- Department of Biomedical Sciences, The Florida State University College of Medicine, Tallahassee, Florida, USA
| | - Nicol Voermans
- Department of Neurology and Human Genetics, Radboud University Medical Center, Nijmegen, Netherlands
| | - Carsten G Bönnemann
- Neuromuscular and Neurogenetic Disorders of Childhood Section, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland, USA
| | - Coen Ac Ottenheijm
- Deptartment of Physiology, Amsterdam UMC (location VUmc), Amsterdam, Netherlands.,Department of Cellular and Molecular Medicine, University of Arizona, Tucson, Arizona, USA
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6
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Bouman K, Küsters B, De Winter JM, Gillet C, Van Kleef ESB, Eshuis L, Brochier G, Madelaine A, Labasse C, Boulogne C, Van Engelen BGM, Ottenheijm CAC, Romero NB, Voermans NC, Malfatti E. NEM6, KBTBD13-Related Congenital Myopathy: Myopathological Analysis in 18 Dutch Patients Reveals Ring Rods Fibers, Cores, Nuclear Clumps, and Granulo-Filamentous Protein Material. J Neuropathol Exp Neurol 2021; 80:366-376. [PMID: 33693846 DOI: 10.1093/jnen/nlab012] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Nemaline myopathy type 6 (NEM6), KBTBD13-related congenital myopathy is caused by mutated KBTBD13 protein that interacts improperly with thin filaments/actin, provoking impaired muscle-relaxation kinetics. We describe muscle morphology in 18 Dutch NEM6 patients and correlate it with clinical phenotype and pathophysiological mechanisms. Rods were found in in 85% of biopsies by light microscopy, and 89% by electron microscopy. A peculiar ring disposition of rods resulting in ring-rods fiber was observed. Cores were found in 79% of NEM6 biopsies by light microscopy, and 83% by electron microscopy. Electron microscopy also disclosed granulofilamentous protein material in 9 biopsies. Fiber type 1 predominance and prominent nuclear internalization were found. Rods were immunoreactive for α-actinin and myotilin. Areas surrounding the rods showed titin overexpression suggesting derangement of the surrounding sarcomeres. NEM6 myopathology hallmarks are prominent cores, rods including ring-rods fibers, nuclear clumps, and granulofilamentous protein material. This material might represent the histopathologic epiphenomenon of altered interaction between mutated KBTBD13 protein and thin filaments. We claim to classify KBTBD13-related congenital myopathy as rod-core myopathy.
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Affiliation(s)
- Karlijn Bouman
- From the Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands.,U1179 UVSQ-INSERM Handicap Neuromusculaire: Physiologie, Biothérapie et Pharmacologie appliquées, UFR Simone Veil-Santé, Université Versailles-Saint-Quentin-en-Yvelines, Paris-Saclay, France
| | - Benno Küsters
- Department of Pathology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Josine M De Winter
- Department of Physiology, Amsterdam University Medical Center, VUmc, The Netherlands
| | - Cynthia Gillet
- Cytometry/Electronic Microscopy/Light Microscopy Facility, Imagerie-Gif, Institute for Integrative Biology of the Cell I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Esmee S B Van Kleef
- From the Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Lilian Eshuis
- Department of Pathology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Guy Brochier
- Unité de Morphologie Neuromusculaire, Institut de Myologie, Groupe Hospitalier Universitaire La Pitié-Salpêtrière, Paris, France
| | - Angeline Madelaine
- Unité de Morphologie Neuromusculaire, Institut de Myologie, Groupe Hospitalier Universitaire La Pitié-Salpêtrière, Paris, France
| | - Clémence Labasse
- Unité de Morphologie Neuromusculaire, Institut de Myologie, Groupe Hospitalier Universitaire La Pitié-Salpêtrière, Paris, France
| | - Claire Boulogne
- Cytometry/Electronic Microscopy/Light Microscopy Facility, Imagerie-Gif, Institute for Integrative Biology of the Cell I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Baziel G M Van Engelen
- From the Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Coen A C Ottenheijm
- Department of Physiology, Amsterdam University Medical Center, VUmc, The Netherlands
| | - Norma B Romero
- Unité de Morphologie Neuromusculaire, Institut de Myologie, Groupe Hospitalier Universitaire La Pitié-Salpêtrière, Paris, France.,Université Sorbonne, INSERM UMRS974, Center for Research in Myology, Centre de référence de Pathologie Neuromusculaire Paris-Est, GHU Pitié-Salpêtrière, Paris, France
| | - Nicol C Voermans
- From the Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Edoardo Malfatti
- U1179 UVSQ-INSERM Handicap Neuromusculaire: Physiologie, Biothérapie et Pharmacologie appliquées, UFR Simone Veil-Santé, Université Versailles-Saint-Quentin-en-Yvelines, Paris-Saclay, France.,APHP, Department of Neurology, Raymond Poincaré Hospital, Centre de Référence de Pathologie Neuromusculaire Nord-Est-Ile-de-France, Garches, France
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7
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Kiss B, Gohlke J, Tonino P, Hourani Z, Kolb J, Strom J, Alekhina O, Smith JE, Ottenheijm C, Gregorio C, Granzier H. Nebulin and Lmod2 are critical for specifying thin-filament length in skeletal muscle. SCIENCE ADVANCES 2020; 6:6/46/eabc1992. [PMID: 33177085 PMCID: PMC7673738 DOI: 10.1126/sciadv.abc1992] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Accepted: 09/23/2020] [Indexed: 06/07/2023]
Abstract
Regulating the thin-filament length in muscle is crucial for controlling the number of myosin motors that generate power. The giant protein nebulin forms a long slender filament that associates along the length of the thin filament in skeletal muscle with functions that remain largely obscure. Here nebulin's role in thin-filament length regulation was investigated by targeting entire super-repeats in the Neb gene; nebulin was either shortened or lengthened by 115 nm. Its effect on thin-filament length was studied using high-resolution structural and functional techniques. Results revealed that thin-filament length is strictly regulated by the length of nebulin in fast muscles. Nebulin's control is less tight in slow muscle types where a distal nebulin-free thin-filament segment exists, the length of which was found to be regulated by leiomodin-2 (Lmod2). We propose that strict length control by nebulin promotes high-speed shortening and that dual-regulation by nebulin/Lmod2 enhances contraction efficiency.
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Affiliation(s)
- Balázs Kiss
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ 85721, USA
| | - Jochen Gohlke
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ 85721, USA
| | - Paola Tonino
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ 85721, USA
| | - Zaynab Hourani
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ 85721, USA
| | - Justin Kolb
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ 85721, USA
| | - Joshua Strom
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ 85721, USA
| | - Olga Alekhina
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ 85721, USA
| | - John E Smith
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ 85721, USA
| | - Coen Ottenheijm
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ 85721, USA
| | - Carol Gregorio
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ 85721, USA
| | - Henk Granzier
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ 85721, USA.
- Allan and Alfie Endowed Chair for Heart Disease in Women Research, Sarver Molecular Cardiovascular Research Program, University of Arizona, Tucson, AZ 85721, USA
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8
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Papadimas GK, Xirou S, Kararizou E, Papadopoulos C. Update on Congenital Myopathies in Adulthood. Int J Mol Sci 2020; 21:ijms21103694. [PMID: 32456280 PMCID: PMC7279481 DOI: 10.3390/ijms21103694] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 05/17/2020] [Accepted: 05/19/2020] [Indexed: 12/11/2022] Open
Abstract
Congenital myopathies (CMs) constitute a group of heterogenous rare inherited muscle diseases with different incidences. They are traditionally grouped based on characteristic histopathological findings revealed on muscle biopsy. In recent decades, the ever-increasing application of modern genetic technologies has not just improved our understanding of their pathophysiology, but also expanded their phenotypic spectrum and contributed to a more genetically based approach for their classification. Later onset forms of CMs are increasingly recognised. They are often considered milder with slower progression, variable clinical presentations and different modes of inheritance. We reviewed the key features and genetic basis of late onset CMs with a special emphasis on those forms that may first manifest in adulthood.
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Li F, Kolb J, Crudele J, Tonino P, Hourani Z, Smith JE, Chamberlain JS, Granzier H. Expressing a Z-disk nebulin fragment in nebulin-deficient mouse muscle: effects on muscle structure and function. Skelet Muscle 2020; 10:2. [PMID: 31992366 PMCID: PMC6986074 DOI: 10.1186/s13395-019-0219-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 12/17/2019] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Nebulin is a critical thin filament-binding protein that spans from the Z-disk of the skeletal muscle sarcomere to near the pointed end of the thin filament. Its massive size and actin-binding property allows it to provide the thin filaments with structural and regulatory support. When this protein is lost, nemaline myopathy occurs. Nemaline myopathy causes severe muscle weakness as well as structural defects on a sarcomeric level. There is no known cure for this disease. METHODS We studied whether sarcomeric structure and function can be improved by introducing nebulin's Z-disk region into a nebulin-deficient mouse model (Neb cKO) through adeno-associated viral (AAV) vector therapy. Following this treatment, the structural and functional characteristics of both vehicle-treated and AAV-treated Neb cKO and control muscles were studied. RESULTS Intramuscular injection of this AAV construct resulted in a successful expression of the Z-disk fragment within the target muscles. This expression was significantly higher in Neb cKO mice than control mice. Analysis of protein expression revealed that the nebulin fragment was localized exclusively to the Z-disks and that Neb cKO expressed the nebulin fragment at levels comparable to the level of full-length nebulin in control mice. Additionally, the Z-disk fragment displaced full-length nebulin in control mice, resulting in nemaline rod body formation and a worsening of muscle function. Neb cKO mice experienced a slight functional benefit from the AAV treatment, with a small increase in force and fatigue resistance. Disease progression was also slowed as indicated by improved muscle structure and myosin isoform expression. CONCLUSIONS This study reveals that nebulin fragments are well-received by nebulin-deficient mouse muscles and that limited functional benefits are achievable.
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Affiliation(s)
- Frank Li
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ, 85721, USA
| | - Justin Kolb
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ, 85721, USA
| | - Julie Crudele
- Department of Neurology, University of Washington, Seattle, WA, 98109-8055, USA
| | - Paola Tonino
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ, 85721, USA
| | - Zaynab Hourani
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ, 85721, USA
| | - John E Smith
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ, 85721, USA
| | | | - Henk Granzier
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ, 85721, USA.
- Medical Research Building, RM 325, 1656 E Mabel St, Tucson, AZ, 85721, USA.
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10
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Mi-Mi L, Farman GP, Mayfield RM, Strom J, Chu M, Pappas CT, Gregorio CC. In vivo elongation of thin filaments results in heart failure. PLoS One 2020; 15:e0226138. [PMID: 31899774 PMCID: PMC6941805 DOI: 10.1371/journal.pone.0226138] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Accepted: 11/20/2019] [Indexed: 12/20/2022] Open
Abstract
A novel cardiac-specific transgenic mouse model was generated to identify the physiological consequences of elongated thin filaments during post-natal development in the heart. Remarkably, increasing the expression levels in vivo of just one sarcomeric protein, Lmod2, results in ~10% longer thin filaments (up to 26% longer in some individual sarcomeres) that produce up to 50% less contractile force. Increasing the levels of Lmod2 in vivo (Lmod2-TG) also allows us to probe the contribution of Lmod2 in the progression of cardiac myopathy because Lmod2-TG mice present with a unique cardiomyopathy involving enlarged atrial and ventricular lumens, increased heart mass, disorganized myofibrils and eventually, heart failure. Turning off of Lmod2 transgene expression at postnatal day 3 successfully prevents thin filament elongation, as well as gross morphological and functional disease progression. We show here that Lmod2 has an essential role in regulating cardiac contractile force and function.
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Affiliation(s)
- Lei Mi-Mi
- Department of Cellular and Molecular Medicine and Sarver Molecular Cardiovascular Research Program, The University of Arizona, Tucson, AZ, United States of America
| | - Gerrie P. Farman
- Department of Cellular and Molecular Medicine and Sarver Molecular Cardiovascular Research Program, The University of Arizona, Tucson, AZ, United States of America
| | - Rachel M. Mayfield
- Department of Cellular and Molecular Medicine and Sarver Molecular Cardiovascular Research Program, The University of Arizona, Tucson, AZ, United States of America
| | - Joshua Strom
- Department of Cellular and Molecular Medicine and Sarver Molecular Cardiovascular Research Program, The University of Arizona, Tucson, AZ, United States of America
| | - Miensheng Chu
- Department of Cellular and Molecular Medicine and Sarver Molecular Cardiovascular Research Program, The University of Arizona, Tucson, AZ, United States of America
| | - Christopher T. Pappas
- Department of Cellular and Molecular Medicine and Sarver Molecular Cardiovascular Research Program, The University of Arizona, Tucson, AZ, United States of America
| | - Carol C. Gregorio
- Department of Cellular and Molecular Medicine and Sarver Molecular Cardiovascular Research Program, The University of Arizona, Tucson, AZ, United States of America
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Tinklenberg JA, Siebers EM, Beatka MJ, Fickau BA, Ayres S, Meng H, Yang L, Simpson P, Granzier HL, Lawlor MW. Myostatin Inhibition Using ActRIIB-mFc Does Not Produce Weight Gain or Strength in the Nebulin Conditional KO Mouse. J Neuropathol Exp Neurol 2019; 78:130-139. [PMID: 30597051 DOI: 10.1093/jnen/nly120] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Mutations in at least 12 genes are responsible for a group of congenital skeletal muscle diseases known as nemaline myopathies (NMs). NMs are associated with a range of clinical symptoms and pathological changes often including the presence of cytoplasmic rod-like structures (nemaline bodies) and myofiber hypotrophy. Our recent work has identified a variable degree of behavioral benefit when treating 2 NM mouse models due to mutations in Acta1 with myostatin inhibition. This study is focused on the effects of delivering ActRIIB-mFc (Acceleron; a myostatin inhibitor) to the nebulin conditional knockout KO (Neb cKO) mouse model of NM. Treatment of Neb cKO mice with ActRIIB-mFc did not produce increases in weight gain, strength, myofiber size, or hypertrophic pathway signaling. Overall, our studies demonstrate a lack of response in Neb cKO mice to myostatin inhibition, which differs from the response observed when treating other NM models.
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Affiliation(s)
- Jennifer A Tinklenberg
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine.,Neuroscience Research Center Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Emily M Siebers
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine.,Neuroscience Research Center Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Margaret J Beatka
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine.,Neuroscience Research Center Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Brittany A Fickau
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine.,Neuroscience Research Center Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Samuel Ayres
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine.,Neuroscience Research Center Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Hui Meng
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine
| | - Lin Yang
- Department of Biomedical Engineering, University of Florida, Gainesville, Florida
| | - Pippa Simpson
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine
| | - Henk L Granzier
- Division of Quantitative Health Sciences, Department of Pediatrics Medical College of Wisconsin, Milwaukee, Wisconsin (PS); and College of Medicine, University of Arizona, Tucson, Arizona
| | - Michael W Lawlor
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine.,Neuroscience Research Center Medical College of Wisconsin, Milwaukee, Wisconsin
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12
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D'Amico A, Fattori F, Fiorillo C, Paglietti MG, Testa MBC, Verardo M, Catteruccia M, Bruno C, Bertini E. 'Amish Nemaline Myopathy' in 2 Italian siblings harbouring a novel homozygous mutation in Troponin-I gene. Neuromuscul Disord 2019; 29:766-770. [PMID: 31604653 DOI: 10.1016/j.nmd.2019.09.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 06/10/2019] [Accepted: 09/02/2019] [Indexed: 02/06/2023]
Abstract
Amish Nemaline Myopathy is a severe form of nemaline myopathy associated to mutation in TNNT1 gene, firstly reported among the Old Order Amish. Here we report two Italian siblings who manifested, by the age of 7 months, progressive and severe muscle weakness and wasting, respiratory insufficiency, pectus carinatum deformity and failure to thrive. Muscle biopsy was consistent with nemaline myopathy and novel homozygous missense mutation in TNNT1 was found. Our cases expand the mutational spectrum of TNNT1, confirm the invariable peculiar clinical phenotype also outside the Amish population, and suggest that TNNT1 should be considered for molecular analysis in NM patients with chest deformities and progressive contractures.
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Affiliation(s)
- Adele D'Amico
- Unit of Muscular and Neurodegenerative Disorders, Department of Neurosciences and Neurorehabilitation, Bambino Gesù Children's Hospital, Piazza S. Onofrio 4, 00165 Rome, Italy.
| | - Fabiana Fattori
- Unit of Muscular and Neurodegenerative Disorders, Department of Neurosciences and Neurorehabilitation, Bambino Gesù Children's Hospital, Piazza S. Onofrio 4, 00165 Rome, Italy
| | - Chiara Fiorillo
- Paediatric Neurology and Neuromuscular Disorders Unit, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Istituto Giannina Gaslini, Genoa, Italy
| | - Maria Giovanna Paglietti
- Respiratory Unit, Academic Department of Pediatrics, Bambino Gesù Children's Hospital, IRCCS, Piazza di Sant' Onofrio 4, 00165 Rome, Italy
| | - Maria Beatrice Chiarini Testa
- Respiratory Unit, Academic Department of Pediatrics, Bambino Gesù Children's Hospital, IRCCS, Piazza di Sant' Onofrio 4, 00165 Rome, Italy
| | - Margherita Verardo
- Unit of Muscular and Neurodegenerative Disorders, Department of Neurosciences and Neurorehabilitation, Bambino Gesù Children's Hospital, Piazza S. Onofrio 4, 00165 Rome, Italy
| | - Michela Catteruccia
- Unit of Muscular and Neurodegenerative Disorders, Department of Neurosciences and Neurorehabilitation, Bambino Gesù Children's Hospital, Piazza S. Onofrio 4, 00165 Rome, Italy
| | - Claudio Bruno
- Center of Translational and Experimental Myology, Istituto Giannina Gaslini, Genova, Italy
| | - Enrico Bertini
- Unit of Muscular and Neurodegenerative Disorders, Department of Neurosciences and Neurorehabilitation, Bambino Gesù Children's Hospital, Piazza S. Onofrio 4, 00165 Rome, Italy
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13
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Dominantly inherited distal nemaline/cap myopathy caused by a large deletion in the nebulin gene. Neuromuscul Disord 2018; 29:97-107. [PMID: 30679003 DOI: 10.1016/j.nmd.2018.12.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 11/29/2018] [Accepted: 12/16/2018] [Indexed: 11/20/2022]
Abstract
We report the first family with a dominantly inherited mutation of the nebulin gene (NEB). This ∼100 kb in-frame deletion encompasses NEB exons 14-89, causing distal nemaline/cap myopathy in a three-generation family. It is the largest deletion characterized in NEB hitherto. The mutated allele was shown to be expressed at the mRNA level and furthermore, for the first time, a deletion was shown to cause the production of a smaller mutant nebulin protein. Thus, we suggest that this novel mutant nebulin protein has a dominant-negative effect, explaining the first documented dominant inheritance of nebulin-caused myopathy. The index patient, a young man, was more severely affected than his mother and grandmother. His first symptom was foot drop at the age of three, followed by distal muscle atrophy, slight hypomimia, high-arched palate, and weakness of the neck and elbow flexors, hands, tibialis anterior and toe extensors. Muscle biopsies showed myopathic features with type 1 fibre predominance in the index patient and nemaline bodies and cap-like structures in biopsies from his mother and grandmother. The muscle biopsy findings constitute a further example of nemaline bodies and cap-like structures being part of the same spectrum of pathological changes.
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Huang K, Luo YE, Li QX, Duan HQ, Bi FF, Yang H, Luo YB. [Clinical, pathological and genetic studies of two cases of childhood-onset nemaline myopathy]. ZHONGGUO DANG DAI ER KE ZA ZHI = CHINESE JOURNAL OF CONTEMPORARY PEDIATRICS 2018; 20:804-808. [PMID: 30369353 PMCID: PMC7389041 DOI: 10.7499/j.issn.1008-8830.2018.10.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 04/22/2018] [Accepted: 08/15/2018] [Indexed: 06/08/2023]
Abstract
This article reports two cases of childhood-onset nemaline myopathy diagnosed by muscle pathology and genetic diagnosis. The two patients had onset in early childhood, with muscle weakness as the first manifestation, as well as long disease duration and slow progression. Gomori staining and hematoxylin-eosin staining showed red-stained rods in the sarcoplasmic cytoplasm and sarcolemma under a light microscope. Electron microscopy showed that the dense nemaline rods were located under the muscle fiber sarcolemma and parallel to the long axis of the muscle fibers, and some muscle fiber myofilaments were dissolved and necrotic. Gene testing found that one of the two patients had heterozygous mutation (c.1013A>C) in the ACTA1 gene, and the other had compound heterozygous mutation (c.18676C>T and c.9812C>A) in the NEB gene. The two mutations were more common in nemaline myopathy. Nemaline myopathy is a recessive or dominant inheritance myopathy, in which the nemaline rod in the cytoplasm of myocytes is a characteristic muscle pathological change. Pathological and genetic diagnosis is the gold standard for diagnosis of nemaline myopathy.
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Affiliation(s)
- Kun Huang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha 410008, China.
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15
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Jungbluth H. Myopathology in times of modern imaging. Neuropathol Appl Neurobiol 2018; 43:24-43. [PMID: 28111795 DOI: 10.1111/nan.12385] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2016] [Revised: 01/17/2017] [Accepted: 01/23/2017] [Indexed: 12/14/2022]
Abstract
Over the last two decades, muscle (magnetic resonance) imaging has become an important complementary tool in the diagnosis and differential diagnosis of inherited neuromuscular disorders, particularly in conditions where the pattern of selective muscle involvement is often more predictive of the underlying genetic background than associated clinical and histopathological features. Following an overview of different imaging modalities, the present review will give a concise introduction to systematic image analysis and interpretation in genetic neuromuscular disorders. The pattern of selective muscle involvement will be presented in detail in conditions such as the congenital or myofibrillar myopathies where muscle imaging is particularly useful to inform the (differential) diagnosis, and in disorders such as Duchenne or fascioscapulohumeral muscular dystrophy where the diagnosis is usually made on clinical grounds but where detailed knowledge of disease progression on the muscle imaging level may inform better understanding of the natural history. Utilizing the group of the congenital myopathies as an example, selected case studies will illustrate how muscle MRI can be used to inform the diagnostic process in the clinico-pathological context. Future developments, in particular, concerning the increasing use of whole-body MRI protocols and novel quantitative fat assessments techniques potentially relevant as an outcome measure, will be briefly outlined.
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Affiliation(s)
- H Jungbluth
- Department of Paediatric Neurology, Neuromuscular Service, Evelina's Children Hospital, Guy's & St. Thomas' Hospital NHS Foundation Trust, London, UK.,Randall Division of Cell and Molecular Biophysics, Muscle Signalling Section, London, UK.,Department of Clinical and Basic Neuroscience, IoPPN, King's College, London, UK
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16
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Fattori F, Fiorillo C, Rodolico C, Tasca G, Verardo M, Bellacchio E, Pizzi S, Ciolfi A, Fagiolari G, Lupica A, Broda P, Pedemonte M, Moggio M, Bruno C, Tartaglia M, Bertini E, D'Amico A. Expanding the histopathological spectrum of CFL2
-related myopathies. Clin Genet 2018; 93:1234-1239. [DOI: 10.1111/cge.13240] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 02/13/2018] [Accepted: 02/14/2018] [Indexed: 11/29/2022]
Affiliation(s)
- F. Fattori
- Unit of Neuromuscular and Neurodegenerative Disorders, Genetics and Rare Diseases Research Division; Bambino Gesù Children's Hospital; Rome Italy
| | - C. Fiorillo
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics; Maternal and Child Health, University of Genoa; Genoa Italy
| | - C. Rodolico
- Department of Clinical and Experimental Medicine; University of Messina; Messina Italy
| | - G. Tasca
- Istituto di Neurologia; Università Cattolica del Sacro Cuore, Fondazione Policlinico Universitario "A. Gemelli"; Rome Italy
| | - M. Verardo
- Unit of Neuromuscular and Neurodegenerative Disorders, Genetics and Rare Diseases Research Division; Bambino Gesù Children's Hospital; Rome Italy
| | - E. Bellacchio
- Molecular Genetics and Functional Genomics, Genetics and Rare Diseases Research Division; Bambino Gesù Children's Hospital; Rome Italy
| | - S. Pizzi
- Molecular Genetics and Functional Genomics, Genetics and Rare Diseases Research Division; Bambino Gesù Children's Hospital; Rome Italy
| | - A. Ciolfi
- Molecular Genetics and Functional Genomics, Genetics and Rare Diseases Research Division; Bambino Gesù Children's Hospital; Rome Italy
| | - G. Fagiolari
- Neuromuscular and Rare Disease Unit, Department of Neuroscience, IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico; University of Milan; Milan Italy
| | - A. Lupica
- Department of Clinical and Experimental Medicine; University of Messina; Messina Italy
| | - P. Broda
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics; Maternal and Child Health, University of Genoa; Genoa Italy
| | - M. Pedemonte
- Center of Myology and Neurodegenerative Disease; Istituto Giannina Gaslini; Genova Italy
| | - M. Moggio
- Neuromuscular and Rare Disease Unit, Department of Neuroscience, IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico; University of Milan; Milan Italy
| | - C. Bruno
- Center of Myology and Neurodegenerative Disease; Istituto Giannina Gaslini; Genova Italy
| | - M. Tartaglia
- Molecular Genetics and Functional Genomics, Genetics and Rare Diseases Research Division; Bambino Gesù Children's Hospital; Rome Italy
| | - E. Bertini
- Unit of Neuromuscular and Neurodegenerative Disorders, Genetics and Rare Diseases Research Division; Bambino Gesù Children's Hospital; Rome Italy
- Molecular Genetics and Functional Genomics, Genetics and Rare Diseases Research Division; Bambino Gesù Children's Hospital; Rome Italy
| | - A. D'Amico
- Unit of Neuromuscular and Neurodegenerative Disorders, Genetics and Rare Diseases Research Division; Bambino Gesù Children's Hospital; Rome Italy
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Moreno CDAM, Abath Neto O, Donkervoort S, Hu Y, Reed UC, Oliveira ASB, Bönnemann C, Zanoteli E. Clinical and Histologic Findings in ACTA1-Related Nemaline Myopathy: Case Series and Review of the Literature. Pediatr Neurol 2017; 75:11-16. [PMID: 28780987 DOI: 10.1016/j.pediatrneurol.2017.04.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 03/27/2017] [Accepted: 04/02/2017] [Indexed: 10/19/2022]
Abstract
BACKGROUND Nemaline myopathy is a rare congenital disease of skeletal muscle characterized by muscle weakness and hypotonia, as well as the diagnostic presence of nemaline rods in skeletal muscle fibers. Nemaline myopathy is genetically and phenotypically heterogeneous and, so far, mutations in 11 different genes have been associated with this disease. Dominant mutations in ACTA1 are the second most frequent genetic cause of nemaline myopathy and can lead to a variety of clinical and histologic phenotypes. PATIENTS AND METHODS We present a series of ACTA1-related cases from a Brazilian cohort of 23 patients with nemaline myopathy, diagnosed after Sanger sequencing the entire coding region of ACTA1, and review the literature on ACTA1-related nemaline myopathy. RESULTS The study confirmed ACTA1 mutations in four patients, including one with intranuclear rods, one with large intracytoplasmic aggregates, and two with nemaline intracytoplasmic rods. A repeat muscle biopsy in one patient did not show histological progression. CONCLUSION Despite the recognized phenotypic variability in ACTA1-related nemaline myopathy, clinical and histological presentations appear to correlate with the position of the mutation, which confirms emerging genotype/phenotype correlations and better predict the prognosis of affected patients.
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Affiliation(s)
| | - Osório Abath Neto
- Department of Neurology, Medical School of the University of São Paulo (FMUSP), São Paulo, Brazil; Neuromuscular and Neurogenetics Disorders of Childhood Section, Neurogenetics branch, National Institutes of Neurological Disorders and Stroke, NIH, Bethesda, Maryland
| | - Sandra Donkervoort
- Neuromuscular and Neurogenetics Disorders of Childhood Section, Neurogenetics branch, National Institutes of Neurological Disorders and Stroke, NIH, Bethesda, Maryland
| | - Ying Hu
- Neuromuscular and Neurogenetics Disorders of Childhood Section, Neurogenetics branch, National Institutes of Neurological Disorders and Stroke, NIH, Bethesda, Maryland
| | - Umbertina Conti Reed
- Department of Neurology, Medical School of the University of São Paulo (FMUSP), São Paulo, Brazil
| | | | - Carsten Bönnemann
- Neuromuscular and Neurogenetics Disorders of Childhood Section, Neurogenetics branch, National Institutes of Neurological Disorders and Stroke, NIH, Bethesda, Maryland
| | - Edmar Zanoteli
- Department of Neurology, Medical School of the University of São Paulo (FMUSP), São Paulo, Brazil.
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Colpan M, Ly T, Grover S, Tolkatchev D, Kostyukova AS. The cardiomyopathy-associated K15N mutation in tropomyosin alters actin filament pointed end dynamics. Arch Biochem Biophys 2017; 630:18-26. [PMID: 28732641 DOI: 10.1016/j.abb.2017.07.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Revised: 06/28/2017] [Accepted: 07/13/2017] [Indexed: 10/19/2022]
Abstract
Correct assembly of thin filaments composed of actin and actin-binding proteins is of crucial importance for properly functioning muscle cells. Tropomyosin (Tpm) mediates the binding of tropomodulin (Tmod) and leiomodin (Lmod) at the slow-growing, or pointed, ends of the thin filaments. Together these proteins regulate thin filament lengths and actin dynamics in cardiac muscle. The K15N mutation in the TPM1 gene is associated with familial dilated cardiomyopathy (DCM) but the effect of this mutation on Tpm's function is unknown. In this study, we introduced the K15N mutation in striated muscle α-Tpm (Tpm1.1) and investigated its interaction with actin, Tmod and Lmod. The mutation caused a ∼3-fold decrease in the affinity of Tpm1.1 for actin. The binding of Lmod and Tmod to Tpm1.1-covered actin filaments also decreased in the presence of the K15N mutation. Furthermore, the K15N mutation in Tpm1.1 disrupted the inhibition of actin polymerization and affected the competition between Tmod1 and Lmod2 for binding at the pointed ends. Our data demonstrate that the K15N mutation alters pointed end dynamics by affecting molecular interactions between Tpm1.1, Lmod2 and Tmod1.
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Affiliation(s)
- Mert Colpan
- Voiland School of Chemical Engineering & Bioengineering, Washington State University, Pullman, WA 99164-6515, United States; Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ 85721, United States.
| | - Thu Ly
- Voiland School of Chemical Engineering & Bioengineering, Washington State University, Pullman, WA 99164-6515, United States
| | - Samantha Grover
- Voiland School of Chemical Engineering & Bioengineering, Washington State University, Pullman, WA 99164-6515, United States
| | - Dmitri Tolkatchev
- Voiland School of Chemical Engineering & Bioengineering, Washington State University, Pullman, WA 99164-6515, United States
| | - Alla S Kostyukova
- Voiland School of Chemical Engineering & Bioengineering, Washington State University, Pullman, WA 99164-6515, United States.
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Mild clinical presentation in KLHL40-related nemaline myopathy (NEM 8). Neuromuscul Disord 2016; 26:712-716. [DOI: 10.1016/j.nmd.2016.07.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Revised: 07/01/2016] [Accepted: 07/25/2016] [Indexed: 11/22/2022]
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20
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Nemaline myopathies: State of the art. Rev Neurol (Paris) 2016; 172:614-619. [PMID: 27659899 DOI: 10.1016/j.neurol.2016.08.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Revised: 08/11/2016] [Accepted: 08/22/2016] [Indexed: 12/12/2022]
Abstract
Nemaline myopathy (NM) is one of the most common forms of congenital myopathy. The condition is defined by the histopathological finding of nemaline bodies (rods) on muscle biopsy and is associated with hypotonia and muscle weakness. The clinical spectrum encompasses lethal forms presenting in the neonatal period with profound weakness and less severe congenital diseases of later onset. NM is significantly heterogeneous from a genetic point of view, and its inheritance can be autosomal-dominant (AD), sporadic or autosomal-recessive (AR). To date, 11 genes encoding proteins of skeletal muscle thin filaments, Kelch domain-associated proteins and an unconventional myosin have been implicated in NM. The mechanisms leading to nemaline body formation and muscle weakness are still largely unclear. This report reviews the clinical, histopathological and genetic features of NM, with a focus on some of the recently discovered forms.
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21
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Jungbluth H, Ochala J, Treves S, Gautel M. Current and future therapeutic approaches to the congenital myopathies. Semin Cell Dev Biol 2016; 64:191-200. [PMID: 27515125 DOI: 10.1016/j.semcdb.2016.08.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 08/04/2016] [Accepted: 08/08/2016] [Indexed: 12/14/2022]
Abstract
The congenital myopathies - including Central Core Disease (CCD), Multi-minicore Disease (MmD), Centronuclear Myopathy (CNM), Nemaline Myopathy (NM) and Congenital Fibre Type Disproportion (CFTD) - are a genetically heterogeneous group of early-onset neuromuscular conditions characterized by distinct histopathological features, and associated with a substantial individual and societal disease burden. Appropriate supportive management has substantially improved patient morbidity and mortality but there is currently no cure. Recent years have seen an exponential increase in the genetic and molecular understanding of these conditions, leading to the identification of underlying defects in proteins involved in calcium homeostasis and excitation-contraction coupling, thick/thin filament assembly and function, redox regulation, membrane trafficking and/or autophagic pathways. Based on these findings, specific therapies are currently being developed, or are already approaching the clinical trial stage. Despite undeniable progress, therapy development faces considerable challenges, considering the rarity and diversity of specific conditions, and the size and complexity of some of the genes and proteins involved. The present review will summarize the key genetic, histopathological and clinical features of specific congenital myopathies, and outline therapies already available or currently being developed in the context of known pathogenic mechanisms. The relevance of newly discovered molecular mechanisms and novel gene editing strategies for future therapy development will be discussed.
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Affiliation(s)
- Heinz Jungbluth
- Department of Paediatric Neurology, Neuromuscular Service, Evelina's Children Hospital, Guy's & St. Thomas' Hospital NHS Foundation Trust, London, United Kingdom; Randall Division for Cell and Molecular Biophysics, Muscle Signalling Section Biophysics and Cardiovascular Division, King's College BHF Centre of Research Excellence, United Kingdom; Department of Basic and Clinical Neuroscience, IoPPN, King's College, London, United Kingdom.
| | - Julien Ochala
- Centre of Human and Aerospace Physiological Sciences, King's College London, United Kingdom
| | - Susan Treves
- Departments of Biomedicine and Anaesthesia, Basel University Hospital, 4031 Basel, Switzerland
| | - Mathias Gautel
- Randall Division for Cell and Molecular Biophysics, Muscle Signalling Section Biophysics and Cardiovascular Division, King's College BHF Centre of Research Excellence, United Kingdom
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22
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Ly T, Moroz N, Pappas CT, Novak SM, Tolkatchev D, Wooldridge D, Mayfield RM, Helms G, Gregorio CC, Kostyukova AS. The N-terminal tropomyosin- and actin-binding sites are important for leiomodin 2's function. Mol Biol Cell 2016; 27:2565-75. [PMID: 27307584 PMCID: PMC4985258 DOI: 10.1091/mbc.e16-03-0200] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 06/10/2016] [Indexed: 11/11/2022] Open
Abstract
Leiomodin is a potent actin nucleator related to tropomodulin, a capping protein localized at the pointed end of the thin filaments. Mutations in leiomodin-3 are associated with lethal nemaline myopathy in humans, and leiomodin-2-knockout mice present with dilated cardiomyopathy. The arrangement of the N-terminal actin- and tropomyosin-binding sites in leiomodin is contradictory and functionally not well understood. Using one-dimensional nuclear magnetic resonance and the pointed-end actin polymerization assay, we find that leiomodin-2, a major cardiac isoform, has an N-terminal actin-binding site located within residues 43-90. Moreover, for the first time, we obtain evidence that there are additional interactions with actin within residues 124-201. Here we establish that leiomodin interacts with only one tropomyosin molecule, and this is the only site of interaction between leiomodin and tropomyosin. Introduction of mutations in both actin- and tropomyosin-binding sites of leiomodin affected its localization at the pointed ends of the thin filaments in cardiomyocytes. On the basis of our new findings, we propose a model in which leiomodin regulates actin poly-merization dynamics in myocytes by acting as a leaky cap at thin filament pointed ends.
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Affiliation(s)
- Thu Ly
- Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA 99164-6515
| | - Natalia Moroz
- Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA 99164-6515
| | - Christopher T Pappas
- Department of Cellular and Molecular Medicine, Sarver Molecular Cardiovascular Research Program, University of Arizona, Tucson, AZ 85721
| | - Stefanie M Novak
- Department of Cellular and Molecular Medicine, Sarver Molecular Cardiovascular Research Program, University of Arizona, Tucson, AZ 85721
| | - Dmitri Tolkatchev
- Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA 99164-6515
| | - Dayton Wooldridge
- Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA 99164-6515
| | - Rachel M Mayfield
- Department of Cellular and Molecular Medicine, Sarver Molecular Cardiovascular Research Program, University of Arizona, Tucson, AZ 85721
| | - Gregory Helms
- Center for NMR Spectroscopy, Washington State University, Pullman, WA 99164-4630
| | - Carol C Gregorio
- Department of Cellular and Molecular Medicine, Sarver Molecular Cardiovascular Research Program, University of Arizona, Tucson, AZ 85721
| | - Alla S Kostyukova
- Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA 99164-6515
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23
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Lindqvist J, Levy Y, Pati-Alam A, Hardeman EC, Gregorevic P, Ochala J. Modulating myosin restores muscle function in a mouse model of nemaline myopathy. Ann Neurol 2016; 79:717-725. [PMID: 26891371 PMCID: PMC4950341 DOI: 10.1002/ana.24619] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Revised: 02/16/2016] [Accepted: 02/16/2016] [Indexed: 12/18/2022]
Abstract
OBJECTIVE Nemaline myopathy, one of the most common congenital myopathies, is associated with mutations in various genes including ACTA1. This disease is also characterized by various forms/degrees of muscle weakness, with most cases being severe and resulting in death in infancy. Recent findings have provided valuable insight into the underlying pathophysiological mechanisms. Mutations in ACTA1 directly disrupt binding interactions between actin and myosin, and consequently the intrinsic force-generating capacity of muscle fibers. ACTA1 mutations are also associated with variations in myofiber size, the mechanisms of which have been unclear. In the present study, we sought to test the hypotheses that the compromised functional and morphological attributes of skeletal muscles bearing ACTA1 mutations (1) would be directly due to the inefficient actomyosin complex and (2) could be restored by manipulating myosin expression. METHODS We used a knockin mouse model expressing the ACTA1 His40Tyr actin mutation found in human patients. We then performed in vivo intramuscular injections of recombinant adeno-associated viral vectors harboring a myosin transgene known to facilitate muscle contraction. RESULTS We observed that in the presence of the transgene, the intrinsic force-generating capacity was restored and myofiber size was normal. INTERPRETATION This demonstrates a direct link between disrupted attachment of myosin molecules to actin monomers and muscle fiber atrophy. These data also suggest that further therapeutic interventions should primarily target myosin dysfunction to alleviate the pathology of ACTA1-related nemaline myopathy. Ann Neurol 2016;79:717-725.
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Affiliation(s)
- Johan Lindqvist
- Department of Neuroscience, Uppsala University, Uppsala, Sweden
| | - Yotam Levy
- Centre of Human and Aerospace Physiological Sciences, Faculty of Life Sciences & Medicine, King's College London, London, United Kingdom
| | - Alisha Pati-Alam
- Centre of Human and Aerospace Physiological Sciences, Faculty of Life Sciences & Medicine, King's College London, London, United Kingdom
| | - Edna C Hardeman
- Neuromuscular and Regenerative Medicine Unit, School of Medical Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Paul Gregorevic
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
- Department of Biochemistry and Molecular Biology, Monash University, Melbourne, Victoria, Australia
- Department of Physiology, University of Melbourne, Melbourne, Victoria, Australia
- Department of Neurology, University of Washington School of Medicine, Seattle, WA
| | - Julien Ochala
- Centre of Human and Aerospace Physiological Sciences, Faculty of Life Sciences & Medicine, King's College London, London, United Kingdom
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