1
|
Piga D, Rimoldi M, Magri F, Zanotti S, Napoli L, Ripolone M, Pagliarani S, Ciscato P, Velardo D, D’Amico A, Bertini E, Comi GP, Ronchi D, Corti S. Case report: A novel ACTA1 variant in a patient with nemaline rods and increased glycogen deposition. Front Neurol 2024; 15:1340693. [PMID: 38500810 PMCID: PMC10944937 DOI: 10.3389/fneur.2024.1340693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2023] [Accepted: 02/22/2024] [Indexed: 03/20/2024] Open
Abstract
Background Congenital myopathies are a group of heterogeneous inherited disorders, mainly characterized by early-onset hypotonia and muscle weakness. The spectrum of clinical phenotype can be highly variable, going from very mild to severe presentations. The course also varies broadly resulting in a fatal outcome in the most severe cases but can either be benign or lead to an amelioration even in severe presentations. Muscle biopsy analysis is crucial for the identification of pathognomonic morphological features, such as core areas, nemaline bodies or rods, nuclear centralizations and congenital type 1 fibers disproportion. However, multiple abnormalities in the same muscle can be observed, making more complex the myopathological scenario. Case presentation Here, we describe an Italian newborn presenting with severe hypotonia, respiratory insufficiency, inability to suck and swallow, requiring mechanical ventilation and gastrostomy feeding. Muscle biopsy analyzed by light microscopy showed the presence of vacuoles filled with glycogen, suggesting a metabolic myopathy, but also fuchsinophilic inclusions. Ultrastructural studies confirmed the presence of normally structured glycogen, and the presence of minirods, directing the diagnostic hypothesis toward a nemaline myopathy. An expanded Next Generation Sequencing analysis targeting congenital myopathies genes revealed the presence of a novel heterozygous c.965 T > A p. (Leu322Gln) variant in the ACTA1 gene, which encodes the skeletal muscle alpha-actin. Conclusion Our case expands the repertoire of molecular and pathological features observed in actinopathies. We highlight the value of ultrastructural examination to investigate the abnormalities detected at the histological level. We also emphasized the use of expanded gene panels in the molecular analysis of neuromuscular patients, especially for those ones presenting multiple bioptic alterations.
Collapse
Affiliation(s)
- Daniela Piga
- IRCCS Fondazione Cà Granda Ospedale Maggiore Policlinico, Neurology Unit, Milan, Italy
| | - Martina Rimoldi
- IRCCS Fondazione Cà Granda Ospedale Maggiore Policlinico, Neuromuscular and Rare Disease Unit, Milan, Italy
- IRCCS Fondazione Cà Granda Ospedale Maggiore Policlinico, Medical Genetics Unit, Milan, Italy
| | - Francesca Magri
- IRCCS Fondazione Cà Granda Ospedale Maggiore Policlinico, Neurology Unit, Milan, Italy
| | - Simona Zanotti
- IRCCS Fondazione Cà Granda Ospedale Maggiore Policlinico, Neuromuscular and Rare Disease Unit, Milan, Italy
| | - Laura Napoli
- IRCCS Fondazione Cà Granda Ospedale Maggiore Policlinico, Neuromuscular and Rare Disease Unit, Milan, Italy
| | - Michela Ripolone
- IRCCS Fondazione Cà Granda Ospedale Maggiore Policlinico, Neuromuscular and Rare Disease Unit, Milan, Italy
| | - Serena Pagliarani
- IRCCS Fondazione Cà Granda Ospedale Maggiore Policlinico, Neurology Unit, Milan, Italy
| | - Patrizia Ciscato
- IRCCS Fondazione Cà Granda Ospedale Maggiore Policlinico, Neuromuscular and Rare Disease Unit, Milan, Italy
| | - Daniele Velardo
- IRCCS Fondazione Cà Granda Ospedale Maggiore Policlinico, Neuromuscular and Rare Disease Unit, Milan, Italy
| | - Adele D’Amico
- Unit of Neuromuscular and Neurodegenerative Disorders, Bambino Gesu’ Children’s Research Hospital, IRCCS, Rome, Italy
| | - Enrico Bertini
- Unit of Neuromuscular and Neurodegenerative Disorders, Bambino Gesu’ Children’s Research Hospital, IRCCS, Rome, Italy
| | - Giacomo Pietro Comi
- IRCCS Fondazione Cà Granda Ospedale Maggiore Policlinico, Neurology Unit, Milan, Italy
- Department of Pathophysiology and Transplantation, Dino Ferrari Center, University of Milan, Milan, Italy
| | - Dario Ronchi
- IRCCS Fondazione Cà Granda Ospedale Maggiore Policlinico, Neurology Unit, Milan, Italy
- Department of Pathophysiology and Transplantation, Dino Ferrari Center, University of Milan, Milan, Italy
| | - Stefania Corti
- IRCCS Fondazione Cà Granda Ospedale Maggiore Policlinico, Neuromuscular and Rare Disease Unit, Milan, Italy
- Department of Pathophysiology and Transplantation, Dino Ferrari Center, University of Milan, Milan, Italy
| |
Collapse
|
2
|
Chong JX, Childers MC, Marvin CT, Marcello AJ, Gonorazky H, Hazrati LN, Dowling JJ, Al Amrani F, Alanay Y, Nieto Y, Gabriel MÁM, Aylsworth AS, Buckingham KJ, Shively KM, Sommers O, Anderson K, Regnier M, Bamshad MJ. Variants in ACTC1 underlie distal arthrogryposis accompanied by congenital heart defects. HGG ADVANCES 2023; 4:100213. [PMID: 37457373 PMCID: PMC10345160 DOI: 10.1016/j.xhgg.2023.100213] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 06/12/2023] [Indexed: 07/18/2023] Open
Abstract
Contraction of the human sarcomere is the result of interactions between myosin cross-bridges and actin filaments. Pathogenic variants in genes such as MYH7, TPM1, and TNNI3 that encode parts of the cardiac sarcomere cause muscle diseases that affect the heart, such as dilated cardiomyopathy and hypertrophic cardiomyopathy. In contrast, pathogenic variants in homologous genes such as MYH2, TPM2, and TNNI2 that encode parts of the skeletal muscle sarcomere cause muscle diseases affecting skeletal muscle, such as distal arthrogryposis (DA) syndromes and skeletal myopathies. To date, there have been few reports of genes (e.g., MYH7) encoding sarcomeric proteins in which the same pathogenic variant affects skeletal and cardiac muscle. Moreover, none of the known genes underlying DA have been found to contain pathogenic variants that also cause cardiac abnormalities. We report five families with DA because of heterozygous missense variants in the gene actin, alpha, cardiac muscle 1 (ACTC1). ACTC1 encodes a highly conserved actin that binds to myosin in cardiac and skeletal muscle. Pathogenic variants in ACTC1 have been found previously to underlie atrial septal defect, dilated cardiomyopathy, hypertrophic cardiomyopathy, and left ventricular noncompaction. Our discovery delineates a new DA condition because of variants in ACTC1 and suggests that some functions of ACTC1 are shared in cardiac and skeletal muscle.
Collapse
Affiliation(s)
- Jessica X. Chong
- Division of Genetic Medicine, Department of Pediatrics, University of Washington, Seattle, WA 98195, USA
- Brotman-Baty Institute, Seattle, WA 98195, USA
| | - Matthew Carter Childers
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA
- University of Washington Center for Translational Muscle Research, Seattle, WA 98195, USA
| | - Colby T. Marvin
- Division of Genetic Medicine, Department of Pediatrics, University of Washington, Seattle, WA 98195, USA
| | - Anthony J. Marcello
- Division of Genetic Medicine, Department of Pediatrics, University of Washington, Seattle, WA 98195, USA
| | - Hernan Gonorazky
- Division of Neurology, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada
| | - Lili-Naz Hazrati
- Department of Paediatric Laboratory Medicine, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada
| | - James J. Dowling
- Division of Neurology, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada
- Departments of Paediatrics and Molecular Genetics, University of Toronto, Toronto, ON M5G 0A4, Canada
| | - Fatema Al Amrani
- Division of Neurology, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada
- Division of Neurology, Department of Pediatrics, Sultan Qaboos University Hospital, Sultan Qaboos University, Muscat, Sultanate of Oman
| | - Yasemin Alanay
- Division of Pediatric Genetics, Department of Pediatrics, School of Medicine, Acibadem Mehmet Ali Aydinlar University, 34752 Istanbul, Turkey
| | - Yolanda Nieto
- Department of Basic Bio-Medical Sciences, European University of Madrid, Madrid, Spain
| | - Miguel Á Marín Gabriel
- Department of Pediatrics, Puerta de Hierro-Majadahonda University Hospital, 28221 Madrid, Spain
| | - Arthur S. Aylsworth
- Departments of Pediatrics and Genetics, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Kati J. Buckingham
- Division of Genetic Medicine, Department of Pediatrics, University of Washington, Seattle, WA 98195, USA
| | - Kathryn M. Shively
- Division of Genetic Medicine, Department of Pediatrics, University of Washington, Seattle, WA 98195, USA
| | - Olivia Sommers
- Division of Genetic Medicine, Department of Pediatrics, University of Washington, Seattle, WA 98195, USA
| | - Kailyn Anderson
- Division of Genetic Medicine, Department of Pediatrics, University of Washington, Seattle, WA 98195, USA
| | - University of Washington Center for Mendelian Genomics
- Division of Genetic Medicine, Department of Pediatrics, University of Washington, Seattle, WA 98195, USA
- Brotman-Baty Institute, Seattle, WA 98195, USA
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA
- University of Washington Center for Translational Muscle Research, Seattle, WA 98195, USA
- Division of Neurology, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada
- Department of Paediatric Laboratory Medicine, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada
- Departments of Paediatrics and Molecular Genetics, University of Toronto, Toronto, ON M5G 0A4, Canada
- Division of Neurology, Department of Pediatrics, Sultan Qaboos University Hospital, Sultan Qaboos University, Muscat, Sultanate of Oman
- Division of Pediatric Genetics, Department of Pediatrics, School of Medicine, Acibadem Mehmet Ali Aydinlar University, 34752 Istanbul, Turkey
- Department of Basic Bio-Medical Sciences, European University of Madrid, Madrid, Spain
- Department of Pediatrics, Puerta de Hierro-Majadahonda University Hospital, 28221 Madrid, Spain
- Departments of Pediatrics and Genetics, University of North Carolina, Chapel Hill, NC 27599, USA
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
- Seattle Children’s Hospital, Seattle, WA 98105, USA
| | - University of Washington Center for Rare Disease Research
- Division of Genetic Medicine, Department of Pediatrics, University of Washington, Seattle, WA 98195, USA
- Brotman-Baty Institute, Seattle, WA 98195, USA
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA
- University of Washington Center for Translational Muscle Research, Seattle, WA 98195, USA
- Division of Neurology, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada
- Department of Paediatric Laboratory Medicine, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada
- Departments of Paediatrics and Molecular Genetics, University of Toronto, Toronto, ON M5G 0A4, Canada
- Division of Neurology, Department of Pediatrics, Sultan Qaboos University Hospital, Sultan Qaboos University, Muscat, Sultanate of Oman
- Division of Pediatric Genetics, Department of Pediatrics, School of Medicine, Acibadem Mehmet Ali Aydinlar University, 34752 Istanbul, Turkey
- Department of Basic Bio-Medical Sciences, European University of Madrid, Madrid, Spain
- Department of Pediatrics, Puerta de Hierro-Majadahonda University Hospital, 28221 Madrid, Spain
- Departments of Pediatrics and Genetics, University of North Carolina, Chapel Hill, NC 27599, USA
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
- Seattle Children’s Hospital, Seattle, WA 98105, USA
| | - Michael Regnier
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA
- University of Washington Center for Translational Muscle Research, Seattle, WA 98195, USA
| | - Michael J. Bamshad
- Division of Genetic Medicine, Department of Pediatrics, University of Washington, Seattle, WA 98195, USA
- Brotman-Baty Institute, Seattle, WA 98195, USA
- University of Washington Center for Translational Muscle Research, Seattle, WA 98195, USA
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
- Seattle Children’s Hospital, Seattle, WA 98105, USA
| |
Collapse
|
3
|
Chong JX, Childers MC, Marvin CT, Marcello AJ, Gonorazky H, Hazrati LN, Dowling JJ, Amrani FA, Alanay Y, Nieto Y, Marín Gabriel MÁ, Aylsworth AS, Buckingham KJ, Shively KM, Sommers O, Anderson K, Regnier M, Bamshad MJ. Variants in ACTC1 underlie distal arthrogryposis accompanied by congenital heart defects. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023. [PMID: 36945405 PMCID: PMC10029015 DOI: 10.1101/2023.03.07.23286862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/11/2023]
Abstract
Contraction of the human sarcomere is the result of interactions between myosin cross-bridges and actin filaments. Pathogenic variants in genes such as MYH7 , TPM1 , and TNNI3 that encode parts of the cardiac sarcomere cause muscle diseases that affect the heart, such as dilated cardiomyopathy and hypertrophic cardiomyopathy. In contrast, pathogenic variants in homologous genes MYH2 , TPM2 , and TNNI2 , that encode parts of the skeletal muscle sarcomere, cause muscle diseases affecting skeletal muscle, such as the distal arthrogryposis (DA) syndromes and skeletal myopathies. To date, there have been few reports of genes (e.g., MYH7 ) encoding sarcomeric proteins in which the same pathogenic variant affects both skeletal and cardiac muscle. Moreover, none of the known genes underlying DA have been found to contain mutations that also cause cardiac abnormalities. We report five families with DA due to heterozygous missense variants in the gene actin, alpha, cardiac muscle 1 ( ACTC1 ). ACTC1 encodes a highly conserved actin that binds to myosin in both cardiac and skeletal muscle. Mutations in ACTC1 have previously been found to underlie atrial septal defect, dilated cardiomyopathy, hypertrophic cardiomyopathy, and left ventricular noncompaction. Our discovery delineates a new DA condition due to mutations in ACTC1 and suggests that some functions of actin, alpha, cardiac muscle 1 are shared in cardiac and skeletal muscle.
Collapse
|
4
|
Díaz Expósito A, Robles Mezcua A, Pérez Cabeza AI, García Pinilla JM. A new mutation in the ACTA1 gene possibly associated with dilated cardiomyopathy without concomitant myopathy. REVISTA ESPANOLA DE CARDIOLOGIA (ENGLISH ED.) 2022; 75:850-852. [PMID: 35597757 DOI: 10.1016/j.rec.2022.03.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Accepted: 03/22/2022] [Indexed: 06/15/2023]
Affiliation(s)
- Arancha Díaz Expósito
- Unidad de Insuficiencia Cardiaca y Cardiopatías Familiares, Hospital Universitario Virgen de la Victoria, Instituto de Investigación Biomédica de Málaga (IBIMA), Málaga, Spain.
| | - Ainhoa Robles Mezcua
- Unidad de Insuficiencia Cardiaca y Cardiopatías Familiares, Hospital Universitario Virgen de la Victoria, Instituto de Investigación Biomédica de Málaga (IBIMA), Málaga, Spain
| | - Alejandro I Pérez Cabeza
- Unidad de Insuficiencia Cardiaca y Cardiopatías Familiares, Hospital Universitario Virgen de la Victoria, Instituto de Investigación Biomédica de Málaga (IBIMA), Málaga, Spain; Centro de Investigación en Red de Enfermedades Cardiovasculares (CIBERCV), Spain
| | - José Manuel García Pinilla
- Unidad de Insuficiencia Cardiaca y Cardiopatías Familiares, Hospital Universitario Virgen de la Victoria, Instituto de Investigación Biomédica de Málaga (IBIMA), Málaga, Spain; Centro de Investigación en Red de Enfermedades Cardiovasculares (CIBERCV), Spain
| |
Collapse
|
5
|
Matsumoto A, Tsuda H, Furui S, Kawada-Nagashima M, Anzai T, Seki M, Watanabe K, Muramatsu K, Osaka H, Iwamoto S, Nishino I, Yamagata T. A case of congenital fiber-type disproportion syndrome presenting dilated cardiomyopathy with ACTA1 mutation. Mol Genet Genomic Med 2022; 10:e2008. [PMID: 35757965 PMCID: PMC9482392 DOI: 10.1002/mgg3.2008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 05/03/2022] [Accepted: 06/08/2022] [Indexed: 01/06/2023] Open
Abstract
Background Actin, alpha, skeletal muscle 1 (ACTA1) is one of the causative genes of nemaline myopathy (NM) and congenital fiber‐type disproportion (CFTD). CFTD is characterized by type 1 fiber atrophy and distinguished from NM in the absence of rods. Eight patients with CFTD, including one patient with dilated cardiomyopathy (DCM), have previously been reported. Herein, we report the case of a 10‐year‐old boy presenting with CFTD and DCM. Methods We performed exome sequencing and analyzed the effect of Met327Lys mutations on cultured C2C12 muscle cells compared with that seen in the wild type (WT, ACTA1) and previously identified Asp294Val mutations associated with a severe phenotype of CFTD without cardiomyopathy. Results Exome sequencing revealed a de novo mutation, c.980 T > A, p.(Met327Lys), in ACTA1 (NM_001100.4). C2C12 cells transfected with the WT plasmid expressed ACTA1 in the nucleus and cytoplasm. Cells with the Asp294Val mutant showed needle‐like structures in the cytoplasm, whereas the expression of the Met327Lys mutant resulted in few aggregations but many apoptotic cells. Conclusion Apoptosis induced in Met327Lys‐transfected muscle cells supports the pathogenicity of the mutation and can be implicated as one of the histopathological features associated with CFTD, as in NM.
Collapse
Affiliation(s)
- Ayumi Matsumoto
- Department of Pediatrics, Jichi Medical University, Tochigi, Japan.,Division of Human Genetics, Center for Molecular Medicine, Jichi Medical University, Tochigi, Japan
| | - Hidetoshi Tsuda
- Division of Human Genetics, Center for Molecular Medicine, Jichi Medical University, Tochigi, Japan
| | - Sadahiro Furui
- Department of Pediatrics, Jichi Medical University, Tochigi, Japan
| | | | - Tatsuya Anzai
- Department of Pediatrics, Jichi Medical University, Tochigi, Japan
| | - Mitsuru Seki
- Department of Pediatrics, Jichi Medical University, Tochigi, Japan
| | - Kazuhisa Watanabe
- Division of Human Genetics, Center for Molecular Medicine, Jichi Medical University, Tochigi, Japan
| | | | - Hitoshi Osaka
- Department of Pediatrics, Jichi Medical University, Tochigi, Japan
| | - Sadahiko Iwamoto
- Division of Human Genetics, Center for Molecular Medicine, Jichi Medical University, Tochigi, Japan
| | - Ichizo Nishino
- Department of Neuromuscular Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), Tokyo, Japan
| | | |
Collapse
|
6
|
Díaz Expósito A, Robles Mezcua A, Pérez Cabeza AI, García Pinilla JM. Una nueva mutación en el gen ACTA1, posiblemente asociada con miocardiopatía dilatada sin miopatía concomitante. Rev Esp Cardiol 2022. [DOI: 10.1016/j.recesp.2022.03.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
7
|
Christophers B, Lopez MA, Gupta VA, Vogel H, Baylies M. Pediatric Nemaline Myopathy: A Systematic Review Using Individual Patient Data. J Child Neurol 2022; 37:652-663. [PMID: 36960434 PMCID: PMC10032635 DOI: 10.1177/08830738221096316] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Nemaline myopathy is a skeletal muscle disease that affects 1 in 50 000 live births. The objective of this study was to develop a narrative synthesis of the findings of a systematic review of the latest case descriptions of patients with NM. A systematic search of MEDLINE, Embase, CINAHL, Web of Science, and Scopus was performed using Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines using the keywords pediatric, child, NM, nemaline rod, and rod myopathy. Case studies focused on pediatric NM and published in English between January 1, 2010, and December 31, 2020, in order to represent the most recent findings. Information was collected about the age of first signs, earliest presenting neuromuscular signs and symptoms, systems affected, progression, death, pathologic description, and genetic changes. Of a total of 385 records, 55 case reports or series were reviewed, covering 101 pediatric patients from 23 countries. We review varying presentations in children ranging in severity despite being caused by the same mutation, in addition to current and future clinical considerations relevant to the care of patients with NM. This review synthesizes genetic, histopathologic, and disease presentation findings from pediatric NM case reports. These data strengthen our understanding of the wide spectrum of disease seen in NM. Future studies are needed to identify the underlying molecular mechanism of pathology, to improve diagnostics, and to develop better methods to improve the quality of life for these patients.
Collapse
Affiliation(s)
- Briana Christophers
- Weill Cornell/Rockefeller/Sloan Kettering Tri-Institutional MD-PhD Program, New York, NY, USA
| | | | - Vandana A. Gupta
- Brigham and Women’s Hospital and Harvard Medical School, Boston, MA, USA
| | | | - Mary Baylies
- Weill Cornell/Rockefeller/Sloan Kettering Tri-Institutional MD-PhD Program, New York, NY, USA
- Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| |
Collapse
|
8
|
Critical Evaluation of Current Hypotheses for the Pathogenesis of Hypertrophic Cardiomyopathy. Int J Mol Sci 2022; 23:ijms23042195. [PMID: 35216312 PMCID: PMC8880276 DOI: 10.3390/ijms23042195] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 02/07/2022] [Accepted: 02/14/2022] [Indexed: 02/04/2023] Open
Abstract
Hereditary hypertrophic cardiomyopathy (HCM), due to mutations in sarcomere proteins, occurs in more than 1/500 individuals and is the leading cause of sudden cardiac death in young people. The clinical course exhibits appreciable variability. However, typically, heart morphology and function are normal at birth, with pathological remodeling developing over years to decades, leading to a phenotype characterized by asymmetric ventricular hypertrophy, scattered fibrosis and myofibrillar/cellular disarray with ultimate mechanical heart failure and/or severe arrhythmias. The identity of the primary mutation-induced changes in sarcomere function and how they trigger debilitating remodeling are poorly understood. Support for the importance of mutation-induced hypercontractility, e.g., increased calcium sensitivity and/or increased power output, has been strengthened in recent years. However, other ideas that mutation-induced hypocontractility or non-uniformities with contractile instabilities, instead, constitute primary triggers cannot yet be discarded. Here, we review evidence for and criticism against the mentioned hypotheses. In this process, we find support for previous ideas that inefficient energy usage and a blunted Frank–Starling mechanism have central roles in pathogenesis, although presumably representing effects secondary to the primary mutation-induced changes. While first trying to reconcile apparently diverging evidence for the different hypotheses in one unified model, we also identify key remaining questions and suggest how experimental systems that are built around isolated primarily expressed proteins could be useful.
Collapse
|
9
|
Cardiac Complications of Neuromuscular Disorders. Neuromuscul Disord 2022. [DOI: 10.1016/b978-0-323-71317-7.00003-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
10
|
Laitila J, Wallgren-Pettersson C. Recent advances in nemaline myopathy. Neuromuscul Disord 2021; 31:955-967. [PMID: 34561123 DOI: 10.1016/j.nmd.2021.07.012] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2021] [Revised: 07/14/2021] [Accepted: 07/16/2021] [Indexed: 11/18/2022]
Abstract
The nemaline myopathies constitute a large proportion of the congenital or structural myopathies. Common to all patients is muscle weakness and the presence in the muscle biopsy of nemaline rods. The causative genes are at least twelve, encoding structural or regulatory proteins of the thin filament, and the clinical picture as well as the histological appearance on muscle biopsy vary widely. Here, we suggest a renewed clinical classification to replace the original one, summarise what is known about the pathogenesis from mutations in each causative gene to the forms of nemaline myopathy described to date, and provide perspectives on pathogenetic mechanisms possibly open to therapeutic modalities.
Collapse
Affiliation(s)
- Jenni Laitila
- The Folkhälsan Institute of Genetics, Folkhälsan Research Center, Helsinki, Finland; Department of Medical Genetics, Medicum, University of Helsinki, Finland; Department of Biomedical Sciences, University of Copenhagen, Denmark.
| | - Carina Wallgren-Pettersson
- The Folkhälsan Institute of Genetics, Folkhälsan Research Center, Helsinki, Finland; Department of Medical Genetics, Medicum, University of Helsinki, Finland
| |
Collapse
|
11
|
Lornage X, Quijano-Roy S, Amthor H, Carlier RY, Monnier N, Deleuze JF, Romero NB, Laporte J, Böhm J. Asymmetric muscle weakness due to ACTA1 mosaic mutations. Neurology 2020; 95:e3406-e3411. [DOI: 10.1212/wnl.0000000000010947] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 08/06/2020] [Indexed: 11/15/2022] Open
Abstract
ObjectiveTo characterize 2 unrelated patients with either asymmetric or unilateral muscle weakness at the clinical, genetic, histologic, and ultrastructural level.MethodsThe patients underwent thorough clinical examination, whole-body MRI, and exome sequencing. Muscle morphology was assessed by histology and electron microscopy.ResultsBoth patients presented with early-onset hypotonia, delayed motor milestones, scoliosis, and reduced pulmonary function. Patient P1 manifested unilateral muscle weakness exclusively affecting the left side of the body; the asymmetry was less pronounced in patient P2. Muscle biopsies from both patients showed nemaline rods as the main histopathologic hallmark, and MRI revealed major fatty infiltrations in selective head, proximal, and distal muscles, correlating with the degree of muscle weakness asymmetry. Exome sequencing on blood DNA from both patients identified de novo ACTA1 missense mutations in a small number of reads, suggesting mutation mosaicism. Subsequent Sanger sequencing confirmed the presence of the mutations on muscle DNA, while they were barely detectable on blood DNA.ConclusionsDe novo mutations can occur anytime during embryonic development and may result in a mosaic pattern of affected cells and tissues and lead to the development of an asymmetric clinical picture. The present study points out that mosaic mutations might not be easily detectable on leukocyte DNA and thereby escape routine genetic analysis, and possibly account for a significant number of molecularly undiagnosed patients.
Collapse
|
12
|
Besser RR, Bowles AC, Alassaf A, Carbonero D, Maciel R, Saporta M, Agarwal A. A Chemically Defined Common Medium for Culture of C2C12 Skeletal Muscle and Human Induced Pluripotent Stem Cell Derived Spinal Spheroids. Cell Mol Bioeng 2020; 13:605-619. [PMID: 33281990 DOI: 10.1007/s12195-020-00624-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 06/03/2020] [Indexed: 01/14/2023] Open
Abstract
Introduction Multicellular platforms and linked multi organ on chip devices are powerful tools for drug discovery, and basic mechanistic studies. Often, a critical constraint is defining a culture medium optimal for all cells present in the system. In this study, we focused on the key cells of the neuromuscular junction i.e., skeletal muscle and motor neurons. Methods Formulation of a chemically defined medium for the co-culture of C2C12 skeletal muscle cells and human induced pluripotent stem cell (hiPSC) derived spinal spheroids (SpS) was optimized. C2C12 cells in 10 experimental media conditions and 2 topographies were evaluated over a 14-day maturation period to determine the ideal medium formulation for skeletal muscle tissue development. Results During early maturation, overexpression of genes for myogenesis and myopathy was observed for several media conditions, corresponding to muscle delamination and death. Together, we identified 3 media formulations that allowed for more controlled differentiation, healthier muscle tissue, and long-term culture duration. This evidence was then used to select media formulations to culture SpS and subsequently assessed axonal growth. As axonal growth in SpS cultures was comparable in all selected media conditions, our data suggest that the neuronal basal medium with no added supplements is the ideal medium formulation for both cell types. Conclusions Optimization using both topographical cues and culture media formulations provides a comprehensive analyses of culture conditions that are vital to future applications for in vitro NMJ models.
Collapse
Affiliation(s)
- Rachel R Besser
- Department of Biomedical Engineering, DJTMF Biomedical Nanotechnology Institute, University of Miami, 1251 Memorial Dr, MEA 203, Coral Gables, FL 33146 USA
| | - Annie C Bowles
- Department of Biomedical Engineering, DJTMF Biomedical Nanotechnology Institute, University of Miami, 1251 Memorial Dr, MEA 203, Coral Gables, FL 33146 USA
| | - Ahmad Alassaf
- Department of Biomedical Engineering, DJTMF Biomedical Nanotechnology Institute, University of Miami, 1251 Memorial Dr, MEA 203, Coral Gables, FL 33146 USA.,Department of Medical Equipment Technology, College of Applied Medical Sciences, Majmaah University, Al-Majmaah, 11952 Saudi Arabia
| | - Daniel Carbonero
- Department of Biomedical Engineering, DJTMF Biomedical Nanotechnology Institute, University of Miami, 1251 Memorial Dr, MEA 203, Coral Gables, FL 33146 USA
| | - Renata Maciel
- Department of Neurology, University of Miami Miller School of Medicine, 1120 NW 14th St, Suite 1310, Miami, FL 33136 USA
| | - Mario Saporta
- Department of Neurology, University of Miami Miller School of Medicine, 1120 NW 14th St, Suite 1310, Miami, FL 33136 USA
| | - Ashutosh Agarwal
- Department of Biomedical Engineering, DJTMF Biomedical Nanotechnology Institute, University of Miami, 1251 Memorial Dr, MEA 203, Coral Gables, FL 33146 USA
| |
Collapse
|
13
|
Pott A, Rottbauer W, Just S. Streamlining drug discovery assays for cardiovascular disease using zebrafish. Expert Opin Drug Discov 2019; 15:27-37. [PMID: 31570020 DOI: 10.1080/17460441.2020.1671351] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Introduction: In the last decade, our armamentarium of cardiovascular drug therapy has expanded significantly. Using innovative functional genomics strategies such as genome editing by CRISPR/Cas9 as well as high-throughput assays to identify bioactive small chemical compounds has significantly facilitated elaboration of the underlying pathomechanism in various cardiovascular diseases. However, despite scientific progress approvals for cardiovascular drugs has stagnated significantly compared to other fields of drug discovery and therapy during the past years.Areas covered: In this review, the authors discuss the aspects and pitfalls during the early phase of cardiovascular drug discovery and describe the advantages of zebrafish as an in vivo organism to model human cardiovascular diseases (CVD) as well as an in vivo platform for high-throughput chemical compound screening. They also highlight the emerging, promising techniques of automated read-out systems during high-throughput screening (HTS) for the evaluation of important cardiac functional parameters in zebrafish with the potential to streamline CVD drug discovery.Expert opinion: The successful identification of novel drugs to treat CVD is a major challenge in modern biomedical and clinical research. In this context, the definition of the etiologic fundamentals of human cardiovascular diseases is the prerequisite for an efficient and straightforward drug discovery.
Collapse
Affiliation(s)
- Alexander Pott
- Internal Medicine II, Ulm University Medical Center, Ulm, Germany.,Molecular Cardiology, Internal Medicine II, Ulm University Medical Center, Ulm, Germany
| | | | - Steffen Just
- Molecular Cardiology, Internal Medicine II, Ulm University Medical Center, Ulm, Germany
| |
Collapse
|
14
|
Sewry CA, Laitila JM, Wallgren-Pettersson C. Nemaline myopathies: a current view. J Muscle Res Cell Motil 2019; 40:111-126. [PMID: 31228046 PMCID: PMC6726674 DOI: 10.1007/s10974-019-09519-9] [Citation(s) in RCA: 108] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 05/29/2019] [Indexed: 12/13/2022]
Abstract
Nemaline myopathies are a heterogenous group of congenital myopathies caused by de novo, dominantly or recessively inherited mutations in at least twelve genes. The genes encoding skeletal α-actin (ACTA1) and nebulin (NEB) are the commonest genetic cause. Most patients have congenital onset characterized by muscle weakness and hypotonia, but the spectrum of clinical phenotypes is broad, ranging from severe neonatal presentations to onset of a milder disorder in childhood. Most patients with adult onset have an autoimmune-related myopathy with a progressive course. The wide application of massively parallel sequencing methods is increasing the number of known causative genes and broadening the range of clinical phenotypes. Nemaline myopathies are identified by the presence of structures that are rod-like or ovoid in shape with electron microscopy, and with light microscopy stain red with the modified Gömöri trichrome technique. These rods or nemaline bodies are derived from Z lines (also known as Z discs or Z disks) and have a similar lattice structure and protein content. Their shape in patients with mutations in KLHL40 and LMOD3 is distinctive and can be useful for diagnosis. The number and distribution of nemaline bodies varies between fibres and different muscles but does not correlate with severity or prognosis. Additional pathological features such as caps, cores and fibre type disproportion are associated with the same genes as those known to cause the presence of rods. Animal models are advancing the understanding of the effects of various mutations in different genes and paving the way for the development of therapies, which at present only manage symptoms and are aimed at maintaining muscle strength, joint mobility, ambulation, respiration and independence in the activities of daily living.
Collapse
Affiliation(s)
- Caroline A Sewry
- Dubowitz Neuromuscular Centre, UCL Institute of Child Health and Great Ormond Street Hospital, 30 Guilford Street, London, WC1N 1EH, UK. .,Wolfson Centre of Inherited Neuromuscular Disorders, RJAH Orthopaedic Hospital, Oswestry, SY10 7AG, UK.
| | - Jenni M Laitila
- Folkhälsan Institute of Genetics, Folkhälsan Research Center, Helsinki, Finland.,Department of Medical and Clinical Genetics, Medicum, University of Helsinki, Helsinki, Finland
| | - Carina Wallgren-Pettersson
- Folkhälsan Institute of Genetics, Folkhälsan Research Center, Helsinki, Finland.,Department of Medical and Clinical Genetics, Medicum, University of Helsinki, Helsinki, Finland
| |
Collapse
|
15
|
Umeki N, Shibata K, Noguchi TQP, Hirose K, Sako Y, Uyeda TQP. K336I mutant actin alters the structure of neighbouring protomers in filaments and reduces affinity for actin-binding proteins. Sci Rep 2019; 9:5353. [PMID: 30926871 PMCID: PMC6441083 DOI: 10.1038/s41598-019-41795-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 03/18/2019] [Indexed: 12/16/2022] Open
Abstract
Mutation of the Lys-336 residue of actin to Ile (K336I) or Asp (K336E) causes congenital myopathy. To understand the effect of this mutation on the function of actin filaments and gain insight into the mechanism of disease onset, we prepared and biochemically characterised K336I mutant actin from Dictyostelium discoideum. Subtilisin cleavage assays revealed that the structure of the DNase-I binding loop (D-loop) of monomeric K336I actin, which would face the adjacent actin-protomer in filaments, differed from that of wild type (WT) actin. Although K336I actin underwent normal salt-dependent reversible polymerisation and formed apparently normal filaments, interactions of K336I filaments with alpha-actinin, myosin II, and cofilin were disrupted. Furthermore, co-filaments of K336I and WT actins also exhibited abnormal interactions with cofilin, implying that K336I actin altered the structure of the neighbouring WT actin protomers such that interaction between cofilin and the WT actin protomers was prevented. We speculate that disruption of the interactions between co-filaments and actin-binding proteins is the primary reason why the K336I mutation induces muscle disease in a dominant fashion.
Collapse
Affiliation(s)
- Nobuhisa Umeki
- Cellular Informatics Lab., RIKEN, Wako, Saitama, 351-0198, Japan. .,Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, 305-8562, Japan.
| | - Keitaro Shibata
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, 305-8562, Japan.,Advanced ICT Research Institute, National Institute of Information and Communications Technology (NICT), Kobe, Hyogo, 651-2492, Japan
| | - Taro Q P Noguchi
- National Institute of Technology, Miyakonojo College, Miyakonojo, Miyazaki, 885-8567, Japan
| | - Keiko Hirose
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, 305-8562, Japan
| | - Yasushi Sako
- Cellular Informatics Lab., RIKEN, Wako, Saitama, 351-0198, Japan
| | - Taro Q P Uyeda
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, 305-8562, Japan.,Department of Physics, Waseda University, Shinjuku, Tokyo, 169-8555, Japan
| |
Collapse
|
16
|
Petri H, Wahbi K, Witting N, Køber L, Bundgaard H, Kamoun E, Vellieux G, Stojkovic T, Béhin A, Laforet P, Vissing J. Congenital myopathies are mainly associated with a mild cardiac phenotype. J Neurol 2019; 266:1367-1375. [PMID: 30874888 DOI: 10.1007/s00415-019-09267-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 02/27/2019] [Accepted: 03/04/2019] [Indexed: 12/17/2022]
Abstract
BACKGROUND To evaluate the prevalence of cardiac involvement in patients with congenital myopathies and the association to specific genotypes. METHODS We evaluated patients with physical examination, electrocardiogram, echocardiography, and 48-h Holter monitoring. Follow-up was performed for major events. RESULTS We included 130 patients, 55 men (42%), with a mean age of 34 ± 17 years. A genetic diagnosis was established in 97 patients (75%). Right bundle branch block was observed in three patients: 2/34 patients with a ryanodine receptor 1 (RYR1) and 1/6 with a tropomyosin two gene (TPM2) gene mutation. Echocardiography showed left-ventricular hypertrophy in five patients: 2/17 and 3/34 patients with a Dynamin 2 (DNM2) and a RYR1 mutation, respectively. One patient with a myosin heavy-chain (MYH7) mutation had dilated cardiomyopathy and heart failure. On Holter monitoring, frequent ventricular premature contractions were observed in one patient with a DNM2 mutation. Two patients with a TPM2 and a RYR1 mutation, respectively, had a single short run of non-sustained ventricular tachycardia. Atrioventricular nodal re-entry tachycardia was observed in a 20-year-old man with an actin 1 gene mutation. During follow-up (median 8.4 years), four patients died, all of non-cardiac causes. CONCLUSION Congenital myopathies are generally associated with a mild cardiac phenotype. Our findings substantiate the literature and indicate that, except for patients with specific genotypes, such as MYH7 and TTN mutations, repeated cardiac assessments can be minimized, given a normal initial cardiac screening at time of diagnosis.
Collapse
Affiliation(s)
- Helle Petri
- Department of Cardiology, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark.
| | - Karim Wahbi
- APHP, Cochin Hospital, Cardiology Department, Centre de Référence de Pathologie, Neuromusculaire Nord/Est/Ile de France, Paris-Descartes, Sorbonne Paris Cité University, 75006, Paris, France
| | - Nanna Witting
- Department of Neurology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Lars Køber
- Department of Cardiology, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Henning Bundgaard
- Department of Cardiology, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Emna Kamoun
- Myology Institute, Nord/Est/Ile de France Neuromuscular Center, Pitié-Salpêtière hospital, APHP, Paris, France
| | - Geoffroy Vellieux
- Myology Institute, Nord/Est/Ile de France Neuromuscular Center, Pitié-Salpêtière hospital, APHP, Paris, France
| | - Tanya Stojkovic
- Myology Institute, Nord/Est/Ile de France Neuromuscular Center, Pitié-Salpêtière hospital, APHP, Paris, France
| | - Anthony Béhin
- Myology Institute, Nord/Est/Ile de France Neuromuscular Center, Pitié-Salpêtière hospital, APHP, Paris, France
| | - Pascal Laforet
- Neurology Department, Nord/Est/Ile de France Neuromuscular Center, Raymond Poincaré Teaching Hospital, APHP, 92380, Garches, France.,END-ICAP, INSERM U1179, Université Versailles Saint-Quentin-en-Yvelines, Montigny-le-Bretonneux, France
| | - John Vissing
- Department of Neurology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| |
Collapse
|
17
|
Tadokoro K, Ohta Y, Sasaki R, Takahashi Y, Sato K, Shang J, Takemoto M, Hishikawa N, Yamashita T, Nakamura K, Nishino I, Abe K. Congenital myopathy with fiber-type disproportion accompanied by dilated cardiomyopathy in a patient with a novel p.G48A ACTA1 mutation. J Neurol Sci 2018; 393:142-144. [DOI: 10.1016/j.jns.2018.08.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 08/02/2018] [Accepted: 08/16/2018] [Indexed: 10/28/2022]
|
18
|
Chatzifrangkeskou M, Yadin D, Marais T, Chardonnet S, Cohen-Tannoudji M, Mougenot N, Schmitt A, Crasto S, Di Pasquale E, Macquart C, Tanguy Y, Jebeniani I, Pucéat M, Morales Rodriguez B, Goldmann WH, Dal Ferro M, Biferi MG, Knaus P, Bonne G, Worman HJ, Muchir A. Cofilin-1 phosphorylation catalyzed by ERK1/2 alters cardiac actin dynamics in dilated cardiomyopathy caused by lamin A/C gene mutation. Hum Mol Genet 2018; 27:3060-3078. [PMID: 29878125 PMCID: PMC6097156 DOI: 10.1093/hmg/ddy215] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Revised: 05/30/2018] [Accepted: 05/30/2018] [Indexed: 01/01/2023] Open
Abstract
Hyper-activation of extracellular signal-regulated kinase (ERK) 1/2 contributes to heart dysfunction in cardiomyopathy caused by mutations in the lamin A/C gene (LMNA cardiomyopathy). The mechanism of how this affects cardiac function is unknown. We show that active phosphorylated ERK1/2 directly binds to and catalyzes the phosphorylation of the actin depolymerizing factor cofilin-1 on Thr25. Cofilin-1 becomes active and disassembles actin filaments in a large array of cellular and animal models of LMNA cardiomyopathy. In vivo expression of cofilin-1, phosphorylated on Thr25 by endogenous ERK1/2 signaling, leads to alterations in left ventricular function and cardiac actin. These results demonstrate a novel role for cofilin-1 on actin dynamics in cardiac muscle and provide a rationale on how increased ERK1/2 signaling leads to LMNA cardiomyopathy.
Collapse
Affiliation(s)
- Maria Chatzifrangkeskou
- Sorbonne Université, UPMC Paris 06, INSERM UMRS974, Center of Research in Myology, F-75013 Paris, France
| | - David Yadin
- Institute for Chemistry and Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany
| | - Thibaut Marais
- Sorbonne Université, UPMC Paris 06, INSERM UMRS974, Center of Research in Myology, F-75013 Paris, France
| | - Solenne Chardonnet
- Sorbonne Université, UPMC Paris 06, INSERM, UMS29 Omique, F-75013 Paris, France
| | - Mathilde Cohen-Tannoudji
- Sorbonne Université, UPMC Paris 06, INSERM UMRS974, Center of Research in Myology, F-75013 Paris, France
| | - Nathalie Mougenot
- Sorbonne Université, UPMC Paris 06, INSERM, UMS28 Phénotypage du Petit Animal, Paris F-75013, France
| | - Alain Schmitt
- Institut Cochin, INSERM U1016-CNRS UMR 8104, Université Paris Descartes-Sorbonne Paris Cité, Paris F-75014, France
| | - Silvia Crasto
- Istituto Clinico Humanitas IRCCS, Milan, Italy
- Istituto Ricerca Genetica e Biomedica, National Research Council of Italy, Milan 20089, Italy
| | - Elisa Di Pasquale
- Istituto Clinico Humanitas IRCCS, Milan, Italy
- Istituto Ricerca Genetica e Biomedica, National Research Council of Italy, Milan 20089, Italy
| | - Coline Macquart
- Sorbonne Université, UPMC Paris 06, INSERM UMRS974, Center of Research in Myology, F-75013 Paris, France
| | - Yannick Tanguy
- Sorbonne Université, UPMC Paris 06, INSERM UMRS974, Center of Research in Myology, F-75013 Paris, France
| | - Imen Jebeniani
- Faculté de Médecine La Timone, Université Aix-Marseille, INSERM UMR910, Marseille 13005, France
| | - Michel Pucéat
- Faculté de Médecine La Timone, Université Aix-Marseille, INSERM UMR910, Marseille 13005, France
| | - Blanca Morales Rodriguez
- Sorbonne Université, UPMC Paris 06, INSERM UMRS974, Center of Research in Myology, F-75013 Paris, France
| | - Wolfgang H Goldmann
- Department of Physics, Friedrich-Alexander-University of Erlangen-Nuremberg, 91054 Erlangen, Germany
| | - Matteo Dal Ferro
- Cardiovascular Department, Ospedali Riuniti and University of Trieste, Trieste, Italy
| | - Maria-Grazia Biferi
- Sorbonne Université, UPMC Paris 06, INSERM UMRS974, Center of Research in Myology, F-75013 Paris, France
| | - Petra Knaus
- Institute for Chemistry and Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany
| | - Gisèle Bonne
- Sorbonne Université, UPMC Paris 06, INSERM UMRS974, Center of Research in Myology, F-75013 Paris, France
| | - Howard J Worman
- Department of Medicine
- Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Antoine Muchir
- Sorbonne Université, UPMC Paris 06, INSERM UMRS974, Center of Research in Myology, F-75013 Paris, France
| |
Collapse
|
19
|
Gonorazky HD, Bönnemann CG, Dowling JJ. The genetics of congenital myopathies. HANDBOOK OF CLINICAL NEUROLOGY 2018; 148:549-564. [PMID: 29478600 DOI: 10.1016/b978-0-444-64076-5.00036-3] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Congenital myopathies are a clinically and genetically heterogeneous group of conditions that most commonly present at or around the time of birth with hypotonia, muscle weakness, and (often) respiratory distress. Historically, this group of disorders has been subclassified based on muscle histopathologic characteristics. There has been an explosion of gene discovery, and there are now at least 32 different genetic causes of disease. With this increased understanding of the genetic basis of disease has come the knowledge that the mutations in congenital myopathy genes can present with a wide variety of clinical phenotypes and can result in a broad spectrum of histopathologic findings on muscle biopsy. In addition, mutations in several genes can share the same histopathologic features. The identification of new genes and interpretation of different pathomechanisms at a molecular level have helped us to understand the clinical and histopathologic similarities that this group of disorders share. In this review, we highlight the genetic understanding for each subtype, its pathogenesis, and the future key issues in congenital myopathies.
Collapse
Affiliation(s)
- Hernan D Gonorazky
- Division of Neurology and Program of Genetics and Genome Biology, Hospital for Sick Children, Toronto, ON, Canada
| | - Carsten G Bönnemann
- Neuromuscular and Neurogenetic Disorders of Childhood Section, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, United States
| | - James J Dowling
- Division of Neurology and Program of Genetics and Genome Biology, Hospital for Sick Children, Toronto, ON, Canada.
| |
Collapse
|
20
|
The Molecular Mechanisms of Mutations in Actin and Myosin that Cause Inherited Myopathy. Int J Mol Sci 2018; 19:ijms19072020. [PMID: 29997361 PMCID: PMC6073311 DOI: 10.3390/ijms19072020] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2018] [Revised: 07/06/2018] [Accepted: 07/08/2018] [Indexed: 12/23/2022] Open
Abstract
The discovery that mutations in myosin and actin genes, together with mutations in the other components of the muscle sarcomere, are responsible for a range of inherited muscle diseases (myopathies) has revolutionized the study of muscle, converting it from a subject of basic science to a relevant subject for clinical study and has been responsible for a great increase of interest in muscle studies. Myopathies are linked to mutations in five of the myosin heavy chain genes, three of the myosin light chain genes, and three of the actin genes. This review aims to determine to what extent we can explain disease phenotype from the mutant genotype. To optimise our chances of finding the right mechanism we must study a myopathy where there are a large number of different mutations that cause a common phenotype and so are likely to have a common mechanism: a corollary to this criterion is that if any mutation causes the disease phenotype but does not correspond to the proposed mechanism, then the whole mechanism is suspect. Using these criteria, we consider two cases where plausible genotype-phenotype mechanisms have been proposed: the actin “A-triad” and the myosin “mesa/IHD” models.
Collapse
|
21
|
Sewry CA, Wallgren-Pettersson C. Myopathology in congenital myopathies. Neuropathol Appl Neurobiol 2018; 43:5-23. [PMID: 27976420 DOI: 10.1111/nan.12369] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 12/03/2016] [Indexed: 12/18/2022]
Abstract
Congenital myopathies are clinically and genetically a heterogeneous group of early onset neuromuscular disorders, characterized by hypotonia and muscle weakness. Clinical severity and age of onset are variable. Many patients are severely affected at birth while others have a milder, moderately progressive or nonprogressive phenotype. Respiratory weakness is a major clinical aspect that requires regular monitoring. Causative mutations in several genes have been identified that are inherited in a dominant, recessive or X-linked manner, or arise de novo. Muscle biopsies show characteristic pathological features such as nemaline rods/bodies, cores, central nuclei or caps. Small type 1 fibres expressing slow myosin are a common feature and may sometimes be the only abnormality. Small cores (minicores) devoid of mitochondria and areas showing variable myofibrillar disruption occur in several neuromuscular disorders including several forms of congenital myopathy. Muscle biopsies can also show more than one structural defect. There is considerable clinical, pathological and genetic overlap with mutations in one gene resulting in more than one pathological feature, and the same pathological feature being associated with defects in more than one gene. Increasing application of whole exome sequencing is broadening the clinical and pathological spectra in congenital myopathies, but pathology still has a role in clarifying the pathogenicity of gene variants as well as directing molecular analysis.
Collapse
Affiliation(s)
- C A Sewry
- Dubowitz Neuromuscular Centre, UCL Institute of Child Health and Great Ormond Street Hospital for Children, London, UK.,Wolfson Centre for Inherited Neuromuscular Diseases, RJAH Orthopaedic Hospital, Oswestry, UK
| | - C Wallgren-Pettersson
- The Folkhälsan Institute of Genetics and the Department of Medical and Clinical Genetics, University of Helsinki, Helsinki, Finland
| |
Collapse
|
22
|
Tikhomirova TS, Ievlev RS, Suvorina MY, Bobyleva LG, Vikhlyantsev IM, Surin AK, Galzitskaya OV. Search for Functionally Significant Motifs and Amino Acid Residues of Actin. Mol Biol 2018. [DOI: 10.1134/s0026893318010193] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
23
|
Mizuno Y, Mori-Yoshimura M, Oya Y, Nishikawa A, Nishino I, Takahashi Y. [Two cases of nemaline myopathy presenting with hypertrophy of distal limbs with prominent asymmetry]. Rinsho Shinkeigaku 2017; 57:691-697. [PMID: 29070751 DOI: 10.5692/clinicalneurol.cn-001024] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Nemaline myopathy commonly presents with symmetrical proximal weakness. Here we report two cases of nemaline myopathy presenting with distal dominant involvement with prominent asymmetry. Case 1 was a 37-year-old man who recalled frequently falling down and had right calf atrophy since he was 3-years-old. He had right calf muscle atrophy and weakness and steppage gait; his cardiopulmonary function was normal. Case 2 was a 35-year-old man with right calf muscle atrophy and weakness since childhood. He had right dominant distal leg weakness and atrophy together with respiratory failure and started noninvasive positive pressure ventilation. He also developed cardiomyopathy and died from acute respiratory failure due to pneumonia at age 39. Both cases harbored compound heterozygous nebulin (NEB) mutations with c.20131 C>T:p.Arg6711Trp and a nonsense mutation. Nemaline myopathy associated with NEB mutations can present as distal dominant myopathy with prominent asymmetry.
Collapse
Affiliation(s)
- Yukio Mizuno
- Department of Neurology, National Center Hospital, National Center of Neurology and Psychiatry.,Department of Neurology, Yokohama Asahi Chuo General Hospital
| | - Madoka Mori-Yoshimura
- Department of Neurology, National Center Hospital, National Center of Neurology and Psychiatry
| | - Yasushi Oya
- Department of Neurology, National Center Hospital, National Center of Neurology and Psychiatry
| | - Atsuko Nishikawa
- Department of Neuromuscular Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry
| | - Ichizo Nishino
- Department of Neuromuscular Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry.,Department of Genome Medicine Development, Medical Genome Center, National Center of Neurology and Psychiatry
| | - Yuji Takahashi
- Department of Neurology, National Center Hospital, National Center of Neurology and Psychiatry
| |
Collapse
|
24
|
Autosomal dominant distal myopathy due to a novel ACTA1 mutation. Neuromuscul Disord 2017; 27:742-746. [PMID: 28606400 DOI: 10.1016/j.nmd.2017.05.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Revised: 03/06/2017] [Accepted: 05/02/2017] [Indexed: 11/22/2022]
Abstract
Mutations in skeletal muscle α-actin 1-encoding gene (ACTA1) cause autosomal dominant or recessive myopathies with marked clinical and pathological heterogeneity. Patients typically develop generalized or limb-girdle pattern of weakness, but recently a family with scapuloperoneal myopathy was reported. We describe a father and 2 children with childhood-to-juvenile onset distal myopathy, carrying a novel dominant ACTA1 variant, c.757G>C (p.Gly253Arg). Father had delayed motor development and developed significant proximal weakness later in life; he was initially misdiagnosed as having spinal muscular atrophy based on electromyographic findings. His children had predominant anterior distal leg and finger extensor involvement. Nemaline rods were abundant on the daughter's biopsy, absent on the father's initial biopsy, and extremely rare on the father's subsequent biopsy a decade later. The father's second biopsy also showed myofibrillar pathology and rare fibers with actin filament aggregates. The present family expands the spectrum of actinopathy to include a distal myopathy.
Collapse
|
25
|
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.
Collapse
|
26
|
Abstract
OBJECTIVES Little is known about the type, frequency, severity, treatment, and outcome of cardiac disease in nemaline myopathy. This review summarizes and discusses findings concerning the type, prevalence, diagnosis, treatment, and outcome of cardiac involvement in nemaline myopathy. METHODS Review of publications about nemaline myopathy and cardiac disease. RESULTS Altogether, 35 patients with nemaline myopathy with cardiac disease were identified. Age at presentation ranged from 0 to 62 years. In 30 individuals whose gender was described, 22 were male and eight were female. Onset was congenital in 16 patients, infantile in five, and adult in four. Nine patients presented with dilated cardiomyopathy, six with hypertrophic cardiomyopathy, and one with nonspecific cardiomyopathy. Among those with cardiomyopathy, four developed heart failure. One patient experienced sudden cardiac death. A ventricular septal defect was described in two patients. Cardiac treatment included drugs for heart failure (eight patients), implantable cardioverter-defibrillator implantation (one patient), and heart transplant (three patients). Four patients received noninvasive positive-pressure ventilation and two continuous positive-pressure ventilation. The outcome was fatal in 11 patients. CONCLUSIONS Cardiac disease in nemaline myopathy manifests as cardiomyopathy leading to heart failure. If respiratory muscles are affected, the right side of the heart may be secondarily involved. Early detection of cardiac involvement is essential since effective treatment for cardiac disease in nemaline myopathy may be available.
Collapse
|
27
|
Finsterer J, Frank M. Potential causes of sudden cardiac death in nemaline myopathy. Ital J Pediatr 2015; 41:67. [PMID: 26416716 PMCID: PMC4587851 DOI: 10.1186/s13052-015-0175-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 09/21/2015] [Indexed: 11/23/2022] Open
|
28
|
Malfatti E, Böhm J, Lacène E, Beuvin M, Romero NB, Laporte J. A Premature Stop Codon in MYO18B is Associated with Severe Nemaline Myopathy with Cardiomyopathy. J Neuromuscul Dis 2015; 2:219-227. [PMID: 27858739 PMCID: PMC5240573 DOI: 10.3233/jnd-150085] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Background: Nemaline myopathies (NM) are rare and severe muscle diseases characterized by the presence of nemaline bodies (rods) in muscle fibers. Although ten genes have been implicated in the etiology of NM, an important number of patients remain without a molecular diagnosis. Objective: Here we describe the clinical and histopathological features of a sporadic case presenting with severe NM and cardiomyopathy. Using exome sequencing, we aimed to identify the causative gene. Results: We identified a homozygous nonsense mutation in the last exon of MYO18B, leading to a truncated protein lacking the most C-terminal part. MYO18B codes for an unconventional myosin protein and it is mainly expressed in skeletal and cardiac muscles, two tissues severely affected in the patient. We showed that the mutation does not impact on mRNA stability. Immunostaining and Western blot confirmed the absence of the full-length protein. Conclusion: We propose MYO18B as a novel gene associated with nemaline myopathy and cardiomyopathy.
Collapse
Affiliation(s)
- Edoardo Malfatti
- Sorbonne Universités, UPMC Univ Paris 06, INSERM UMRS974, CNRS FRE3617, Center for Research in Myology, GH Pitié-Salpêtrière, 47 Boulevard de l'hôpital, 75013 Paris, France.,Unité de Morphologie Neuromusculaire, Institut de Myologie, Groupe Hospitalier Universitaire La Pitié-Salpêtrière; Paris, France
| | - Johann Böhm
- Department of Translational Medecine, IGBMC, Illkirch, France.,INSERM U964, Illkirch, France.,CNRS, UMR7104, Illkirch, France.,Strasbourg University, Illkirch, France
| | - Emmanuelle Lacène
- Sorbonne Universités, UPMC Univ Paris 06, INSERM UMRS974, CNRS FRE3617, Center for Research in Myology, GH Pitié-Salpêtrière, 47 Boulevard de l'hôpital, 75013 Paris, France.,Unité de Morphologie Neuromusculaire, Institut de Myologie, Groupe Hospitalier Universitaire La Pitié-Salpêtrière; Paris, France.,Centre de référence de Pathologie Neuromusculaire Paris-Est, Institut de Myologie, GHU La Pitié-Salpêtrière, Assistance Publique-Hôpitaux de Paris; Paris, France
| | - Maud Beuvin
- Sorbonne Universités, UPMC Univ Paris 06, INSERM UMRS974, CNRS FRE3617, Center for Research in Myology, GH Pitié-Salpêtrière, 47 Boulevard de l'hôpital, 75013 Paris, France.,Unité de Morphologie Neuromusculaire, Institut de Myologie, Groupe Hospitalier Universitaire La Pitié-Salpêtrière; Paris, France
| | - Norma B Romero
- Sorbonne Universités, UPMC Univ Paris 06, INSERM UMRS974, CNRS FRE3617, Center for Research in Myology, GH Pitié-Salpêtrière, 47 Boulevard de l'hôpital, 75013 Paris, France.,Unité de Morphologie Neuromusculaire, Institut de Myologie, Groupe Hospitalier Universitaire La Pitié-Salpêtrière; Paris, France.,Centre de référence de Pathologie Neuromusculaire Paris-Est, Institut de Myologie, GHU La Pitié-Salpêtrière, Assistance Publique-Hôpitaux de Paris; Paris, France
| | - Jocelyn Laporte
- Department of Translational Medecine, IGBMC, Illkirch, France.,INSERM U964, Illkirch, France.,CNRS, UMR7104, Illkirch, France.,Strasbourg University, Illkirch, France
| |
Collapse
|
29
|
Marseglia L, D'Angelo G, Manti S, Salpietro V, Arrigo T, Cavallari V, Gitto E. Sudden cardiac arrest in a child with nemaline myopathy. Ital J Pediatr 2015; 41:20. [PMID: 25888334 PMCID: PMC4374407 DOI: 10.1186/s13052-015-0124-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Accepted: 03/06/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Nemaline myopathy is a rare, non progressive congenital skeletal muscle disorder defined by the presence of inclusions known as nemaline rods in muscle fibers. Several clinical subtypes have been described, according to degree of muscle weakness, severity and age at onset. The course of nemaline myopathy is very slowly progressive, and death is usually due to respiratory failure. Cardiac involvement is rare and generally considered to be the result of ACTA1 mutations. PATIENT We report the case of a 6 year old boy with typical congenital nemaline myopathy. Nemaline myopathy was confirmed at 3 years of age by muscle biopsy. No mutation of ACTA1, TPM2 and TNNT1 genes was detected. The child died suddenly of cardiac arrest and associated hypoxic-ischemic brain injury, in absence of acute respiratory failure or swallowing difficulties. RESULTS Nemaline cardiomyopathy was suspected, but post mortem cardiac biopsy did not show findings consistent with nemaline myopathy. CONCLUSIONS Congenital typical nemaline myopathy is not necessarily a static or very slowly progressive disorder and acute cardiac deterioration can lead to early death.
Collapse
Affiliation(s)
- Lucia Marseglia
- Neonatal and Pediatric Intensive Care Unit, Department of Pediatrics, University of Messina, Italy, Via Consolare Valeria 1, 98125, Messina, Italy.
| | - Gabriella D'Angelo
- Neonatal and Pediatric Intensive Care Unit, Department of Pediatrics, University of Messina, Italy, Via Consolare Valeria 1, 98125, Messina, Italy.
| | - Sara Manti
- Unit of Paediatric Genetics and Immunology, Department of Paediatrics, University of Messina, Messina, Italy.
| | - Vincenzo Salpietro
- Unit of Paediatric Genetics and Immunology, Department of Paediatrics, University of Messina, Messina, Italy.
| | - Teresa Arrigo
- Unit of Paediatric Genetics and Immunology, Department of Paediatrics, University of Messina, Messina, Italy.
| | | | - Eloisa Gitto
- Neonatal and Pediatric Intensive Care Unit, Department of Pediatrics, University of Messina, Italy, Via Consolare Valeria 1, 98125, Messina, Italy.
| |
Collapse
|
30
|
Nowak KJ, Davis MR, Wallgren-Pettersson C, Lamont PJ, Laing NG. Clinical utility gene card for: Nemaline myopathy - update 2015. Eur J Hum Genet 2015; 23:ejhg201512. [PMID: 25712079 DOI: 10.1038/ejhg.2015.12] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Revised: 12/16/2014] [Accepted: 01/13/2015] [Indexed: 11/09/2022] Open
Affiliation(s)
- Kristen J Nowak
- Centre for Medical Research, The University of Western Australia and the Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, Western Australia, Australia
| | - Mark R Davis
- Department of Diagnostic Genomics, Neurogenetics Laboratory, QEII Medical Centre, Nedlands, Western Australia, Australia
| | - Carina Wallgren-Pettersson
- Department of Medical Genetics, The Folkhälsan Institute of Genetics, Haartman Institute, University of Helsinki, Helsinki, Finland
| | - Phillipa J Lamont
- Department of Diagnostic Genomics, Neurogenetics Laboratory, QEII Medical Centre, Nedlands, Western Australia, Australia
| | - Nigel G Laing
- Centre for Medical Research, The University of Western Australia and the Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, Western Australia, Australia
| |
Collapse
|
31
|
Structure of the F-actin-tropomyosin complex. Nature 2014; 519:114-7. [PMID: 25470062 DOI: 10.1038/nature14033] [Citation(s) in RCA: 283] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Accepted: 11/07/2014] [Indexed: 12/11/2022]
Abstract
Filamentous actin (F-actin) is the major protein of muscle thin filaments, and actin microfilaments are the main component of the eukaryotic cytoskeleton. Mutations in different actin isoforms lead to early-onset autosomal dominant non-syndromic hearing loss, familial thoracic aortic aneurysms and dissections, and multiple variations of myopathies. In striated muscle fibres, the binding of myosin motors to actin filaments is mainly regulated by tropomyosin and troponin. Tropomyosin also binds to F-actin in smooth muscle and in non-muscle cells and stabilizes and regulates the filaments there in the absence of troponin. Although crystal structures for monomeric actin (G-actin) are available, a high-resolution structure of F-actin is still missing, hampering our understanding of how disease-causing mutations affect the function of thin muscle filaments and microfilaments. Here we report the three-dimensional structure of F-actin at a resolution of 3.7 Å in complex with tropomyosin at a resolution of 6.5 Å, determined by electron cryomicroscopy. The structure reveals that the D-loop is ordered and acts as a central region for hydrophobic and electrostatic interactions that stabilize the F-actin filament. We clearly identify map density corresponding to ADP and Mg(2+) and explain the possible effect of prominent disease-causing mutants. A comparison of F-actin with G-actin reveals the conformational changes during filament formation and identifies the D-loop as their key mediator. We also confirm that negatively charged tropomyosin interacts with a positively charged groove on F-actin. Comparison of the position of tropomyosin in F-actin-tropomyosin with its position in our previously determined F-actin-tropomyosin-myosin structure reveals a myosin-induced transition of tropomyosin. Our results allow us to understand the role of individual mutations in the genesis of actin- and tropomyosin-related diseases and will serve as a strong foundation for the targeted development of drugs.
Collapse
|
32
|
Transcriptional response to cardiac injury in the zebrafish: systematic identification of genes with highly concordant activity across in vivo models. BMC Genomics 2014; 15:852. [PMID: 25280539 PMCID: PMC4197235 DOI: 10.1186/1471-2164-15-852] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Accepted: 09/25/2014] [Indexed: 12/26/2022] Open
Abstract
Background Zebrafish is a clinically-relevant model of heart regeneration. Unlike mammals, it has a remarkable heart repair capacity after injury, and promises novel translational applications. Amputation and cryoinjury models are key research tools for understanding injury response and regeneration in vivo. An understanding of the transcriptional responses following injury is needed to identify key players of heart tissue repair, as well as potential targets for boosting this property in humans. Results We investigated amputation and cryoinjury in vivo models of heart damage in the zebrafish through unbiased, integrative analyses of independent molecular datasets. To detect genes with potential biological roles, we derived computational prediction models with microarray data from heart amputation experiments. We focused on a top-ranked set of genes highly activated in the early post-injury stage, whose activity was further verified in independent microarray datasets. Next, we performed independent validations of expression responses with qPCR in a cryoinjury model. Across in vivo models, the top candidates showed highly concordant responses at 1 and 3 days post-injury, which highlights the predictive power of our analysis strategies and the possible biological relevance of these genes. Top candidates are significantly involved in cell fate specification and differentiation, and include heart failure markers such as periostin, as well as potential new targets for heart regeneration. For example, ptgis and ca2 were overexpressed, while usp2a, a regulator of the p53 pathway, was down-regulated in our in vivo models. Interestingly, a high activity of ptgis and ca2 has been previously observed in failing hearts from rats and humans. Conclusions We identified genes with potential critical roles in the response to cardiac damage in the zebrafish. Their transcriptional activities are reproducible in different in vivo models of cardiac injury. Electronic supplementary material The online version of this article (doi:10.1186/1471-2164-15-852) contains supplementary material, which is available to authorized users.
Collapse
|
33
|
North KN, Wang CH, Clarke N, Jungbluth H, Vainzof M, Dowling JJ, Amburgey K, Quijano-Roy S, Beggs AH, Sewry C, Laing NG, Bönnemann CG. Approach to the diagnosis of congenital myopathies. Neuromuscul Disord 2014; 24:97-116. [PMID: 24456932 PMCID: PMC5257342 DOI: 10.1016/j.nmd.2013.11.003] [Citation(s) in RCA: 176] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Revised: 11/06/2013] [Accepted: 11/08/2013] [Indexed: 10/26/2022]
Abstract
Over the past decade there have been major advances in defining the genetic basis of the majority of congenital myopathy subtypes. However the relationship between each congenital myopathy, defined on histological grounds, and the genetic cause is complex. Many of the congenital myopathies are due to mutations in more than one gene, and mutations in the same gene can cause different muscle pathologies. The International Standard of Care Committee for Congenital Myopathies performed a literature review and consulted a group of experts in the field to develop a summary of (1) the key features common to all forms of congenital myopathy and (2) the specific features that help to discriminate between the different genetic subtypes. The consensus statement was refined by two rounds of on-line survey, and a three-day workshop. This consensus statement provides guidelines to the physician assessing the infant or child with hypotonia and weakness. We summarise the clinical features that are most suggestive of a congenital myopathy, the major differential diagnoses and the features on clinical examination, investigations, muscle pathology and muscle imaging that are suggestive of a specific genetic diagnosis to assist in prioritisation of genetic testing of known genes. As next generation sequencing becomes increasingly used as a diagnostic tool in clinical practise, these guidelines will assist in determining which sequence variations are likely to be pathogenic.
Collapse
Affiliation(s)
- Kathryn N North
- Murdoch Childrens Research Institute, Royal Children's Hospital, Flemington Road, Parkville, Melbourne, Victoria 3052, Australia; Institute for Neuroscience and Muscle Research, The Children's Hospital at Westmead, University of Sydney, Sydney, Australia.
| | - Ching H Wang
- Driscoll Children's Hospital, Corpus Christi, TX, United States
| | - Nigel Clarke
- Institute for Neuroscience and Muscle Research, The Children's Hospital at Westmead, University of Sydney, Sydney, Australia
| | - Heinz Jungbluth
- Evelina Children's Hospital, Department of Paediatric Neurology, London, United Kingdom; Randall Division for Cell and Molecular Biophysics, Muscle Signalling Section, King's College, London, United Kingdom; Clinical Neuroscience Division, IoP, London, United Kingdom
| | - Mariz Vainzof
- Human Genome Research Center, University of Sao Paulo, Sao Paulo, Brazil
| | - James J Dowling
- Division of Neurology, Department of Paediatrics, Hospital for Sick Children, Toronto, ON, Canada
| | - Kimberly Amburgey
- Division of Neurology, Department of Paediatrics, Hospital for Sick Children, Toronto, ON, Canada
| | - Susana Quijano-Roy
- Department of Pediatrics, Garches Neuromuscular Reference Center (GNMH), APHP Raymond Poincare University Hospital (UVSQ), Garches, France
| | - Alan H Beggs
- Children's Hospital Boston, Boston, MA, United States
| | - Caroline Sewry
- Dubowitz Neuromuscular Centre, London, United Kingdom; Wolfson Centre of Inherited Neuromuscular Diseases, RJAH Orthopaedic Hospital, Oswestry, United Kingdom
| | - Nigel G Laing
- Centre for Medical Research, University of Western Australia and Harry Perkins Institute of Medical Research, QQ Building, QEII Medical Centre, Nedlands, Western Australia 6009, Australia
| | - Carsten G Bönnemann
- Neuromuscular and Neurogenetic Disorders of Childhood Section, National Institute of Neurological Disorders and Stroke, Bethesda, MD, United States
| |
Collapse
|
34
|
Marston S, Memo M, Messer A, Papadaki M, Nowak K, McNamara E, Ong R, El-Mezgueldi M, Li X, Lehman W. Mutations in repeating structural motifs of tropomyosin cause gain of function in skeletal muscle myopathy patients. Hum Mol Genet 2013; 22:4978-87. [PMID: 23886664 DOI: 10.1093/hmg/ddt345] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The congenital myopathies include a wide spectrum of clinically, histologically and genetically variable neuromuscular disorders many of which are caused by mutations in genes for sarcomeric proteins. Some congenital myopathy patients have a hypercontractile phenotype. Recent functional studies demonstrated that ACTA1 K326N and TPM2 ΔK7 mutations were associated with hypercontractility that could be explained by increased myofibrillar Ca(2+) sensitivity. A recent structure of the complex of actin and tropomyosin in the relaxed state showed that both these mutations are located in the actin-tropomyosin interface. Tropomyosin is an elongated molecule with a 7-fold repeated motif of around 40 amino acids corresponding to the 7 actin monomers it interacts with. Actin binds to tropomyosin electrostatically at two points, through Asp25 and through a cluster of amino acids that includes Lys326, mutated in the gain-of-function mutation. Asp25 interacts with tropomyosin K6, next to K7 that was mutated in the other gain-of-function mutation. We identified four tropomyosin motifs interacting with Asp25 (K6-K7, K48-K49, R90-R91 and R167-K168) and three E-E/D-K/R motifs interacting with Lys326 (E139, E181 and E218), and we predicted that the known skeletal myopathy mutations ΔK7, ΔK49, R91G, ΔE139, K168E and E181K would cause a gain of function. Tests by an in vitro motility assay confirmed that these mutations increased Ca(2+) sensitivity, while mutations not in these motifs (R167H, R244G) decreased Ca(2+) sensitivity. The work reported here explains the molecular mechanism for 6 out of 49 known disease-causing mutations in the TPM2 and TPM3 genes, derived from structural data of the actin-tropomyosin interface.
Collapse
|
35
|
Ravenscroft G, McNamara E, Griffiths LM, Papadimitriou JM, Hardeman EC, Bakker AJ, Davies KE, Laing NG, Nowak KJ. Cardiac α-actin over-expression therapy in dominant ACTA1 disease. Hum Mol Genet 2013; 22:3987-97. [PMID: 23736297 DOI: 10.1093/hmg/ddt252] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
More than 200 mutations in the skeletal muscle α-actin gene (ACTA1) cause either dominant or recessive skeletal muscle disease. Currently, there are no specific therapies. Cardiac α-actin is 99% identical to skeletal muscle α-actin and the predominant actin isoform in fetal muscle. We previously showed cardiac α-actin can substitute for skeletal muscle α-actin, preventing the early postnatal death of Acta1 knock-out mice, which model recessive ACTA1 disease. Dominant ACTA1 disease is caused by the presence of 'poison' mutant actin protein. Experimental and anecdotal evidence nevertheless indicates that the severity of dominant ACTA1 disease is modulated by the relative amount of mutant skeletal muscle α-actin protein present. Thus, we investigated whether transgenic over-expression of cardiac α-actin in postnatal skeletal muscle could ameliorate the phenotype of mouse models of severe dominant ACTA1 disease. In one model, lethality of ACTA1(D286G). Acta1(+/-) mice was reduced from ∼59% before 30 days of age to ∼12%. In the other model, Acta1(H40Y), in which ∼80% of male mice die by 5 months of age, the cardiac α-actin transgene did not significantly improve survival. Hence cardiac α-actin over-expression is likely to be therapeutic for at least some dominant ACTA1 mutations. The reason cardiac α-actin was not effective in the Acta1(H40Y) mice is uncertain. We showed that the Acta1(H40Y) mice had endogenously elevated levels of cardiac α-actin in skeletal muscles, a finding not reported in dominant ACTA1 patients.
Collapse
|
36
|
Gatayama R, Ueno K, Nakamura H, Yanagi S, Ueda H, Yamagishi H, Yasui S. Nemaline myopathy with dilated cardiomyopathy in childhood. Pediatrics 2013; 131:e1986-90. [PMID: 23650303 DOI: 10.1542/peds.2012-1139] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
We present a case of a 9-year-old boy with nemaline myopathy and dilated cardiomyopathy. The combination of nemaline myopathy and cardiomyopathy is rare, and this is the first reported case of dilated cardiomyopathy associated with childhood-onset nemaline myopathy. A novel mutation, p.W358C, in ACTA1 was detected in this patient. An unusual feature of this case was that the patient's cardiac failure developed during early childhood with no delay of gross motor milestones. The use of a β-blocker did not improve his clinical course, and the patient died 6 months after diagnosis of dilated cardiomyopathy. Congenital nonprogressive nemaline myopathy is not necessarily a benign disorder: deterioration can occur early in the course of dilated cardiomyopathy with neuromuscular disease, and careful clinical evaluation is therefore necessary.
Collapse
Affiliation(s)
- Ryohei Gatayama
- Department of Cardiology, Kanagawa Children's Medical Center, Kanagawa, Kanagawa, Japan.
| | | | | | | | | | | | | |
Collapse
|
37
|
Cardiomyopathy in neurological disorders. Cardiovasc Pathol 2013; 22:389-400. [PMID: 23433859 DOI: 10.1016/j.carpath.2012.12.008] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2012] [Revised: 12/26/2012] [Accepted: 12/30/2012] [Indexed: 12/13/2022] Open
Abstract
According to the American Heart Association, cardiomyopathies are classified as primary (solely or predominantly confined to heart muscle), secondary (those showing pathological myocardial involvement as part of a neuromuscular disorder) and those in which cardiomyopathy is the first/predominant manifestation of a neuromuscular disorder. Cardiomyopathies may be further classified as hypertrophic cardiomyopathy, dilated cardiomyopathy, restrictive cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, or unclassified cardiomyopathy (noncompaction, Takotsubo-cardiomyopathy). This review focuses on secondary cardiomyopathies and those in which cardiomyopathy is the predominant manifestation of a myopathy. Any of them may cause neurological disease, and any of them may be a manifestation of a neurological disorder. Neurological disease most frequently caused by cardiomyopathies is ischemic stroke, followed by transitory ischemic attack, syncope, or vertigo. Neurological disease, which most frequently manifests with cardiomyopathies are the neuromuscular disorders. Most commonly associated with cardiomyopathies are muscular dystrophies, myofibrillar myopathies, congenital myopathies and metabolic myopathies. Management of neurological disease caused by cardiomyopathies is not at variance from the same neurological disorders due to other causes. Management of secondary cardiomyopathies is not different from that of cardiomyopathies due to other causes either. Patients with neuromuscular disorders require early cardiologic investigations and close follow-ups, patients with cardiomyopathies require neurological investigation and avoidance of muscle toxic medication if a neuromuscular disorder is diagnosed. Which patients with cardiomyopathy profit most from primary stroke prevention is unsolved and requires further investigations.
Collapse
|
38
|
Skeletal muscle α-actin diseases (actinopathies): pathology and mechanisms. Acta Neuropathol 2013; 125:19-32. [PMID: 22825594 DOI: 10.1007/s00401-012-1019-z] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Accepted: 07/12/2012] [Indexed: 01/18/2023]
Abstract
Mutations in the skeletal muscle α-actin gene (ACTA1) cause a range of congenital myopathies characterised by muscle weakness and specific skeletal muscle structural lesions. Actin accumulations, nemaline and intranuclear bodies, fibre-type disproportion, cores, caps, dystrophic features and zebra bodies have all been seen in biopsies from patients with ACTA1 disease, with patients frequently presenting with multiple pathologies. Therefore increasingly it is considered that these entities may represent a continuum of structural abnormalities arising due to ACTA1 mutations. Recently an ACTA1 mutation has also been associated with a hypertonic clinical presentation with nemaline bodies. Whilst multiple genes are known to cause many of the pathologies associated with ACTA1 mutations, to date actin aggregates, intranuclear rods and zebra bodies have solely been attributed to ACTA1 mutations. Approximately 200 different ACTA1 mutations have been identified, with 90 % resulting in dominant disease and 10 % resulting in recessive disease. Despite extensive research into normal actin function and the functional consequences of ACTA1 mutations in cell culture, animal models and patient tissue, the mechanisms underlying muscle weakness and the formation of structural lesions remains largely unknown. Whilst precise mechanisms are being grappled with, headway is being made in terms of developing therapeutics for ACTA1 disease, with gene therapy (specifically reducing the proportion of mutant skeletal muscle α-actin protein) and pharmacological agents showing promising results in animal models and patient muscle. The use of small molecules to sensitise the contractile apparatus to Ca(2+) is a promising therapeutic for patients with various neuromuscular disorders, including ACTA1 disease.
Collapse
|
39
|
Myopathies associated with β-tropomyosin mutations. Neuromuscul Disord 2012; 22:923-33. [DOI: 10.1016/j.nmd.2012.05.018] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2012] [Revised: 05/09/2012] [Accepted: 05/31/2012] [Indexed: 12/29/2022]
|
40
|
Sharma S, Liu J, Wei J, Yuan H, Zhang T, Bishopric NH. Repression of miR-142 by p300 and MAPK is required for survival signalling via gp130 during adaptive hypertrophy. EMBO Mol Med 2012; 4:617-32. [PMID: 22367739 PMCID: PMC3407949 DOI: 10.1002/emmm.201200234] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2011] [Revised: 02/16/2012] [Accepted: 02/20/2012] [Indexed: 11/22/2022] Open
Abstract
An increase in cardiac workload, ultimately resulting in hypertrophy, generates oxidative stress and therefore requires the activation of both survival and growth signal pathways. Here, we wanted to characterize the regulators, targets and mechanistic roles of miR-142, a microRNA (miRNA) negatively regulated during hypertrophy. We show that both miRNA-142-3p and -5p are repressed by serum-derived growth factors in cultured cardiac myocytes, in models of cardiac hypertrophy in vivo and in human cardiomyopathic hearts. Levels of miR-142 are inversely related to levels of acetyltransferase p300 and MAPK activity. When present, miR-142 inhibits both survival and growth pathways by directly targeting nodal regulators p300 and gp130. MiR-142 also potently represses multiple components of the NF-κB pathway, preventing cytokine-mediated NO production and blocks translation of α-actinin. Forced expression of miR-142 during hypertrophic growth induced extensive apoptosis and cardiac dysfunction; conversely, loss of miR-142 fully rescued cardiac function in a murine heart failure model. Downregulation of miR-142 is required to enable cytokine-mediated survival signalling during cardiac growth in response to haemodynamic stress and is a critical element of adaptive hypertrophy.
Collapse
Affiliation(s)
- Salil Sharma
- Department of Molecular and Cellular Pharmacology, University of Miami Leonard M. Miller School of Medicine, Miami, FL, USA
| | | | | | | | | | | |
Collapse
|
41
|
Wang CH, Dowling JJ, North K, Schroth MK, Sejersen T, Shapiro F, Bellini J, Weiss H, Guillet M, Amburgey K, Apkon S, Bertini E, Bonnemann C, Clarke N, Connolly AM, Estournet-Mathiaud B, Fitzgerald D, Florence JM, Gee R, Gurgel-Giannetti J, Glanzman AM, Hofmeister B, Jungbluth H, Koumbourlis AC, Laing NG, Main M, Morrison LA, Munns C, Rose K, Schuler PM, Sewry C, Storhaug K, Vainzof M, Yuan N. Consensus statement on standard of care for congenital myopathies. J Child Neurol 2012; 27:363-82. [PMID: 22431881 PMCID: PMC5234865 DOI: 10.1177/0883073812436605] [Citation(s) in RCA: 116] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Recent progress in scientific research has facilitated accurate genetic and neuropathological diagnosis of congenital myopathies. However, given their relatively low incidence, congenital myopathies remain unfamiliar to the majority of care providers, and the levels of patient care are extremely variable. This consensus statement aims to provide care guidelines for congenital myopathies. The International Standard of Care Committee for Congenital Myopathies worked through frequent e-mail correspondences, periodic conference calls, 2 rounds of online surveys, and a 3-day workshop to achieve a consensus for diagnostic and clinical care recommendations. The committee includes 59 members from 10 medical disciplines. They are organized into 5 working groups: genetics/diagnosis, neurology, pulmonology, gastroenterology/nutrition/speech/oral care, and orthopedics/rehabilitation. In each care area the authors summarize the committee's recommendations for symptom assessments and therapeutic interventions. It is the committee's goal that through these recommendations, patients with congenital myopathies will receive optimal care and improve their disease outcome.
Collapse
Affiliation(s)
- Ching H. Wang
- Stanford University School of Medicine, Stanford, CA, USA
| | | | | | - Mary K. Schroth
- University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | | | | | | | - Hali Weiss
- Stanford University School of Medicine, Stanford, CA, USA
| | - Marc Guillet
- A Foundation Building Strength, Palo Alto, CA, USA
| | | | - Susan Apkon
- Seattle Children’s Hospital, Seattle, WA, USA
| | | | | | | | | | | | | | | | - Richard Gee
- Stanford University School of Medicine, Stanford, CA, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | - Kari Storhaug
- National Resource Centre for Oral Health in Rare Medical Conditions, Oslo Norway
| | | | - Nanci Yuan
- Stanford University School of Medicine, Stanford, CA, USA
| |
Collapse
|
42
|
Mir A, Lemler M, Ramaciotti C, Blalock S, Ikemba C. Hypertrophic Cardiomyopathy in a Neonate Associated with Nemaline Myopathy. CONGENIT HEART DIS 2011; 7:E37-41. [DOI: 10.1111/j.1747-0803.2011.00588.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
43
|
Oxford EM, Danko CG, Kornreich BG, Maass K, Hemsley SA, Raskolnikov D, Fox PR, Delmar M, Moïse NS. Ultrastructural changes in cardiac myocytes from Boxer dogs with arrhythmogenic right ventricular cardiomyopathy. J Vet Cardiol 2011; 13:101-13. [PMID: 21636338 PMCID: PMC3142699 DOI: 10.1016/j.jvc.2011.03.002] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2010] [Revised: 02/25/2011] [Accepted: 03/24/2011] [Indexed: 01/22/2023]
Abstract
OBJECTIVES We sought to quantify the number and length of desmosomes, gap junctions, and adherens junctions in arrhythmogenic right ventricular cardiomyopathy (ARVC) and non-ARVC dogs, and to determine if ultrastructural changes existed. ANIMALS Hearts from 8 Boxer dogs afflicted with histopathologically confirmed ARVC and 6 dogs without ARVC were studied. METHODS Quantitative transmission electron microscopy (TEM) and Western blot semi-quantification of α-actinin were used to study the intercalated disc and sarcomere of the right and left ventricles. RESULTS When ARVC dogs were compared to non-ARVC dogs reductions in the number of desmosomes (P = 0.04), adherens junctions (P = 0.04) and gap junctions (P = 0.02) were found. The number of gap junctions (P = 0.04) and adherens junctions (P = 0.04) also were reduced in the left ventricle, while the number of desmosomes was not (P = 0.88). A decrease in the length of desmosomal complexes within LV samples (P = 0.04) was found. These findings suggested disruption of proteins providing attachment of the cytoskeleton to the intercalated disc. Immunoblotting did not demonstrate a quantitative reduction in the amount of α-actinin in ARVC afflicted samples. All Boxers with ARVC demonstrated the presence of electron dense material originating from the Z band and extending into the sarcomere, apparently at the expense of the cytoskeletal structure. CONCLUSIONS These results emphasize the importance of structural integrity of the intercalated disc in the pathogenesis of ARVC. In addition, observed abnormalities in sarcomeric structure suggest a novel link between ARVC and the actin-myosin contractile apparatus.
Collapse
Affiliation(s)
- Eva M. Oxford
- College of Veterinary Medicine, Cornell University, Department of Clinical Sciences, Section of Cardiology, Ithaca, NY 14853, USA
| | - Charles G. Danko
- Cornell University, Department of Biological Statistics and Computational Biology, Ithaca, NY 14853, USA
| | - Bruce G. Kornreich
- College of Veterinary Medicine, Cornell University, Department of Clinical Sciences, Section of Cardiology, Ithaca, NY 14853, USA
| | - Karen Maass
- Leon H. Charney Division of Cardiology, New York University School of Medicine, New York, NY 10016, USA
| | - Shari A. Hemsley
- College of Veterinary Medicine, Cornell University, Department of Clinical Sciences, Section of Cardiology, Ithaca, NY 14853, USA
| | - Dima Raskolnikov
- College of Veterinary Medicine, Cornell University, Department of Clinical Sciences, Section of Cardiology, Ithaca, NY 14853, USA
| | - Philip R. Fox
- Caspary Institute, The Animal Medical Center, New York, NY 10065, USA
| | - Mario Delmar
- Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI 48109, USA
| | - N. Sydney Moïse
- College of Veterinary Medicine, Cornell University, Department of Clinical Sciences, Section of Cardiology, Ithaca, NY 14853, USA
| |
Collapse
|
44
|
Nemaline myopathy and non-fatal hypertrophic cardiomyopathy caused by a novel ACTA1 E239K mutation. J Neurol Sci 2011; 307:171-3. [PMID: 21570694 DOI: 10.1016/j.jns.2011.04.022] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2010] [Revised: 04/13/2011] [Accepted: 04/22/2011] [Indexed: 11/22/2022]
Abstract
A twenty-year old male presented with diffuse limb muscle weakness and exertional dyspnea since childhood. The diagnosis of nemaline myopathy was given based on the muscle pathology findings that revealed nemaline rods on light and electron microscopy and discovery of a novel mutation, E239K, in ACTA1. Incidentally, the patient had hypertrophic cardiomyopathy (HCM) as shown by echocardiography. In nemaline myopathy, a few cases of HCM have been reported, albeit rarely and always fatal, but only one patient had ACTA1 mutation. This present report describes an infantile onset of nemaline myopathy with a milder clinical course and non-fatal HCM as compared with previous cases, showing clinical diversity in skeletal and cardiac manifestations of conditions associated with ACTA1 mutations.
Collapse
|
45
|
Nagata R, Kamimura D, Suzuki Y, Saito T, Toyama H, Dejima T, Inada H, Miwa Y, Uchino K, Umemura S, Shimizu M. A Case of Nemaline Myopathy With Associated Dilated Cardiomyopathy and Respiratory Failure. Int Heart J 2011; 52:401-5. [DOI: 10.1536/ihj.52.401] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
| | - Daisuke Kamimura
- Department of Cardiology, Yaizu City Hospital
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine
| | - Yoji Suzuki
- Department of Neurology, Yaizu City Hospital
| | | | | | - Tohru Dejima
- Department of Cardiology, Yaizu City Hospital
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine
| | | | | | - Kazuaki Uchino
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine
| | - Satoshi Umemura
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine
| | | |
Collapse
|
46
|
Song W, Dyer E, Stuckey D, Leung MC, Memo M, Mansfield C, Ferenczi M, Liu K, Redwood C, Nowak K, Harding S, Clarke K, Wells D, Marston S. Investigation of a transgenic mouse model of familial dilated cardiomyopathy. J Mol Cell Cardiol 2010; 49:380-9. [DOI: 10.1016/j.yjmcc.2010.05.009] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2009] [Revised: 05/17/2010] [Accepted: 05/18/2010] [Indexed: 11/25/2022]
|
47
|
Xu Q, Dewey S, Nguyen S, Gomes AV. Malignant and benign mutations in familial cardiomyopathies: Insights into mutations linked to complex cardiovascular phenotypes. J Mol Cell Cardiol 2010; 48:899-909. [DOI: 10.1016/j.yjmcc.2010.03.005] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2009] [Revised: 03/01/2010] [Accepted: 03/06/2010] [Indexed: 12/17/2022]
|
48
|
Laing NG, Dye DE, Wallgren-Pettersson C, Richard G, Monnier N, Lillis S, Winder TL, Lochmüller H, Graziano C, Mitrani-Rosenbaum S, Twomey D, Sparrow JC, Beggs AH, Nowak KJ. Mutations and polymorphisms of the skeletal muscle alpha-actin gene (ACTA1). Hum Mutat 2009; 30:1267-77. [PMID: 19562689 PMCID: PMC2784950 DOI: 10.1002/humu.21059] [Citation(s) in RCA: 172] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The ACTA1 gene encodes skeletal muscle alpha-actin, which is the predominant actin isoform in the sarcomeric thin filaments of adult skeletal muscle, and essential, along with myosin, for muscle contraction. ACTA1 disease-causing mutations were first described in 1999, when a total of 15 mutations were known. In this article we describe 177 different disease-causing ACTA1 mutations, including 85 that have not been described before. ACTA1 mutations result in five overlapping congenital myopathies: nemaline myopathy; intranuclear rod myopathy; actin filament aggregate myopathy; congenital fiber type disproportion; and myopathy with core-like areas. Mixtures of these histopathological phenotypes may be seen in a single biopsy from one patient. Irrespective of the histopathology, the disease is frequently clinically severe, with many patients dying within the first year of life. Most mutations are dominant and most patients have de novo mutations not present in the peripheral blood DNA of either parent. Only 10% of mutations are recessive and they are genetic or functional null mutations. To aid molecular diagnosis and establishing genotype-phenotype correlations, we have developed a locus-specific database for ACTA1 variations (http://waimr.uwa.edu.au).
Collapse
Affiliation(s)
- Nigel G Laing
- Centre for Medical Research, University of Western Australia, Western Australian Institute for Medical Research, QEII Medical Centre, Western Australia, Australia.
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
49
|
Laing NG, Wallgren-Pettersson C. 161st ENMC International Workshop on nemaline myopathy and related disorders, Newcastle upon Tyne, 2008. Neuromuscul Disord 2009; 19:300-5. [DOI: 10.1016/j.nmd.2009.02.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2009] [Accepted: 02/02/2009] [Indexed: 12/20/2022]
|
50
|
Abstract
Thin filament integrity is important for the ordered structure and function of skeletal muscles. Mutations within genes that encode thin filament and thin filament-associated proteins can cause muscle disruption, fiber atrophy and alter fiber type composition, leading to muscle weakness. Analyses of patient biopsy samples and tissue culture systems provide rapid methods for studying disease-causing mutations. However, there are limitations to these techniques. Although time consuming, many laboratories are generating and utilizing animal models, in particular the mouse, to study the disease process of various myopathies. This chapter reviews the use of mouse models for thin filament diseases of skeletal muscle and in particular, concentrates on what has been achieved through the generation and characterization of transgenic and knock-in mouse models for the congenital thin filament disease nemaline myopathy. We will review potential therapies that have been trialled on the nemaline models, providing indications for future directions for the treatment of nemaline myopathy patients and muscle weakness in general.
Collapse
|