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Lambert MR, Gussoni E. Tropomyosin 3 (TPM3) function in skeletal muscle and in myopathy. Skelet Muscle 2023; 13:18. [PMID: 37936227 PMCID: PMC10629095 DOI: 10.1186/s13395-023-00327-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Accepted: 10/10/2023] [Indexed: 11/09/2023] Open
Abstract
The tropomyosin genes (TPM1-4) contribute to the functional diversity of skeletal muscle fibers. Since its discovery in 1988, the TPM3 gene has been recognized as an indispensable regulator of muscle contraction in slow muscle fibers. Recent advances suggest that TPM3 isoforms hold more extensive functions during skeletal muscle development and in postnatal muscle. Additionally, mutations in the TPM3 gene have been associated with the features of congenital myopathies. The use of different in vitro and in vivo model systems has leveraged the discovery of several disease mechanisms associated with TPM3-related myopathy. Yet, the precise mechanisms by which TPM3 mutations lead to muscle dysfunction remain unclear. This review consolidates over three decades of research about the role of TPM3 in skeletal muscle. Overall, the progress made has led to a better understanding of the phenotypic spectrum in patients affected by mutations in this gene. The comprehensive body of work generated over these decades has also laid robust groundwork for capturing the multiple functions this protein plays in muscle fibers.
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Affiliation(s)
- Matthias R Lambert
- Division of Genetics and Genomics, Boston Children's Hospital, 300 Longwood Ave., Boston, MA, 02115, USA.
- Department of Pediatrics, Harvard Medical School, Boston, MA, 02115, USA.
| | - Emanuela Gussoni
- Division of Genetics and Genomics, Boston Children's Hospital, 300 Longwood Ave., Boston, MA, 02115, USA
- Department of Pediatrics, Harvard Medical School, Boston, MA, 02115, USA
- The Stem Cell Program, Boston Children's Hospital, Boston, MA, 02115, USA
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2
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Slick RA, Tinklenberg JA, Sutton J, Zhang L, Meng H, Beatka MJ, Vanden Avond M, Prom MJ, Ott E, Montanaro F, Heisner J, Toro R, Granzier H, Geurts AM, Stowe DF, Hill RB, Lawlor MW. Aberrations in Energetic Metabolism and Stress-Related Pathways Contribute to Pathophysiology in the Neb Conditional Knockout Mouse Model of Nemaline Myopathy. THE AMERICAN JOURNAL OF PATHOLOGY 2023; 193:1528-1547. [PMID: 37422147 PMCID: PMC10548278 DOI: 10.1016/j.ajpath.2023.06.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 05/08/2023] [Accepted: 06/08/2023] [Indexed: 07/10/2023]
Abstract
Nemaline myopathy (NM) is a genetically and clinically heterogeneous disease that is diagnosed on the basis of the presence of nemaline rods on skeletal muscle biopsy. Although NM has typically been classified by causative genes, disease severity or prognosis cannot be predicted. The common pathologic end point of nemaline rods (despite diverse genetic causes) and an unexplained range of muscle weakness suggest that shared secondary processes contribute to the pathogenesis of NM. We speculated that these processes could be identified through a proteome-wide interrogation using a mouse model of severe NM in combination with pathway validation and structural/functional analyses. A proteomic analysis was performed using skeletal muscle tissue from the Neb conditional knockout mouse model compared with its wild-type counterpart to identify pathophysiologically relevant biological processes that might impact disease severity or provide new treatment targets. A differential expression analysis and Ingenuity Pathway Core Analysis predicted perturbations in several cellular processes, including mitochondrial dysfunction and changes in energetic metabolism and stress-related pathways. Subsequent structural and functional studies demonstrated abnormal mitochondrial distribution, decreased mitochondrial respiratory function, an increase in mitochondrial transmembrane potential, and extremely low ATP content in Neb conditional knockout muscles relative to wild type. Overall, the findings of these studies support a role for severe mitochondrial dysfunction as a novel contributor to muscle weakness in NM.
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Affiliation(s)
- Rebecca A Slick
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine and Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin; Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin; Clinical and Translational Science Institute, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Jennifer A Tinklenberg
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine and Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin; Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin; Clinical and Translational Science Institute, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Jessica Sutton
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine and Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Liwen Zhang
- Mass Spectrometry and Proteomics Facility, Campus Chemical Instrument Center, The Ohio State University, Columbus, Ohio
| | - Hui Meng
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine and Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Margaret J Beatka
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine and Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Mark Vanden Avond
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine and Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin; Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Mariah J Prom
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine and Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Emily Ott
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine and Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Federica Montanaro
- Dubowitz Neuromuscular Centre, Molecular Neurosciences Section, Developmental Neuroscience Research and Teaching Department, UCL Great Ormond Street Institute of Child Health, London, United Kingdom the NIHR Great Ormond Street Hospital Biomedical Research Centre, London, United Kingdom; NIHR Great Ormond Street Hospital Biomedical Research Centre, London, United Kingdom
| | - James Heisner
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin; Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Rafael Toro
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Henk Granzier
- College of Medicine, University of Arizona, Tucson, Arizona
| | - Aron M Geurts
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin; Mellowes Center for Genomic Sciences and Precision Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - David F Stowe
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin; Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, Wisconsin; Joint Department of Biomedical Engineering, Medical College of Wisconsin and Marquette University, Milwaukee, Wisconsin
| | - R Blake Hill
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Michael W Lawlor
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine and Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin; Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin.
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3
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Gorza L, Sorge M, Seclì L, Brancaccio M. Master Regulators of Muscle Atrophy: Role of Costamere Components. Cells 2021; 10:cells10010061. [PMID: 33401549 PMCID: PMC7823551 DOI: 10.3390/cells10010061] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Revised: 12/28/2020] [Accepted: 12/29/2020] [Indexed: 12/11/2022] Open
Abstract
The loss of muscle mass and force characterizes muscle atrophy in several different conditions, which share the expression of atrogenes and the activation of their transcriptional regulators. However, attempts to antagonize muscle atrophy development in different experimental contexts by targeting contributors to the atrogene pathway showed partial effects in most cases. Other master regulators might independently contribute to muscle atrophy, as suggested by our recent evidence about the co-requirement of the muscle-specific chaperone protein melusin to inhibit unloading muscle atrophy development. Furthermore, melusin and other muscle mass regulators, such as nNOS, belong to costameres, the macromolecular complexes that connect sarcolemma to myofibrils and to the extracellular matrix, in correspondence with specific sarcomeric sites. Costameres sense a mechanical load and transduce it both as lateral force and biochemical signals. Recent evidence further broadens this classic view, by revealing the crucial participation of costameres in a sarcolemmal “signaling hub” integrating mechanical and humoral stimuli, where mechanical signals are coupled with insulin and/or insulin-like growth factor stimulation to regulate muscle mass. Therefore, this review aims to enucleate available evidence concerning the early involvement of costamere components and additional putative master regulators in the development of major types of muscle atrophy.
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Affiliation(s)
- Luisa Gorza
- Department of Biomedical Sciences, University of Padova, 35121 Padova, Italy
- Correspondence:
| | - Matteo Sorge
- Department of Molecular Biotechnology and Health Sciences, University of Torino, 10126 Torino, Italy; (M.S.); (L.S.); (M.B.)
| | - Laura Seclì
- Department of Molecular Biotechnology and Health Sciences, University of Torino, 10126 Torino, Italy; (M.S.); (L.S.); (M.B.)
| | - Mara Brancaccio
- Department of Molecular Biotechnology and Health Sciences, University of Torino, 10126 Torino, Italy; (M.S.); (L.S.); (M.B.)
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4
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Levin E, Leibinger M, Gobrecht P, Hilla A, Andreadaki A, Fischer D. Muscle LIM Protein Is Expressed in the Injured Adult CNS and Promotes Axon Regeneration. Cell Rep 2020; 26:1021-1032.e6. [PMID: 30673598 DOI: 10.1016/j.celrep.2018.12.026] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 09/05/2018] [Accepted: 12/05/2018] [Indexed: 01/01/2023] Open
Abstract
Muscle LIM protein (MLP) has long been regarded as a muscle-specific protein. Here, we report that MLP expression is induced in adult rat retinal ganglion cells (RGCs) upon axotomy, and its expression is correlated with their ability to regenerate injured axons. Specific knockdown of MLP in RGCs compromises axon regeneration, while overexpression in vivo facilitates optic nerve regeneration and regrowth of sensory neurons without affecting neuronal survival. MLP accumulates in the cell body, the nucleus, and in axonal growth cones, which are significantly enlarged by its overexpression. Only the MLP fraction in growth cones is relevant for promoting axon extension. Additional data suggest that MLP acts as an actin cross-linker, thereby facilitating filopodia formation and increasing growth cone motility. Thus, MLP-mediated effects on actin could become a therapeutic strategy for promoting nerve repair.
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Affiliation(s)
- Evgeny Levin
- Division of Experimental Neurology, Medical Faculty, Heinrich Heine University, Merowingerplatz 1a, 40225 Düsseldorf, Germany
| | - Marco Leibinger
- Department of Cell Physiology, Ruhr University of Bochum, Universitätsstraße 150, 44780 Bochum, Germany; Division of Experimental Neurology, Medical Faculty, Heinrich Heine University, Merowingerplatz 1a, 40225 Düsseldorf, Germany
| | - Philipp Gobrecht
- Department of Cell Physiology, Ruhr University of Bochum, Universitätsstraße 150, 44780 Bochum, Germany; Division of Experimental Neurology, Medical Faculty, Heinrich Heine University, Merowingerplatz 1a, 40225 Düsseldorf, Germany
| | - Alexander Hilla
- Department of Cell Physiology, Ruhr University of Bochum, Universitätsstraße 150, 44780 Bochum, Germany; Division of Experimental Neurology, Medical Faculty, Heinrich Heine University, Merowingerplatz 1a, 40225 Düsseldorf, Germany
| | - Anastasia Andreadaki
- Department of Cell Physiology, Ruhr University of Bochum, Universitätsstraße 150, 44780 Bochum, Germany; Division of Experimental Neurology, Medical Faculty, Heinrich Heine University, Merowingerplatz 1a, 40225 Düsseldorf, Germany
| | - Dietmar Fischer
- Department of Cell Physiology, Ruhr University of Bochum, Universitätsstraße 150, 44780 Bochum, Germany; Division of Experimental Neurology, Medical Faculty, Heinrich Heine University, Merowingerplatz 1a, 40225 Düsseldorf, Germany.
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5
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Cui C, Han S, Tang S, He H, Shen X, Zhao J, Chen Y, Wei Y, Wang Y, Zhu Q, Li D, Yin H. The Autophagy Regulatory Molecule CSRP3 Interacts with LC3 and Protects Against Muscular Dystrophy. Int J Mol Sci 2020; 21:ijms21030749. [PMID: 31979369 PMCID: PMC7037376 DOI: 10.3390/ijms21030749] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Revised: 01/17/2020] [Accepted: 01/20/2020] [Indexed: 12/22/2022] Open
Abstract
CSRP3/MLP (cysteine-rich protein 3/muscle Lim protein), a member of the cysteine-rich protein family, is a muscle-specific LIM-only factor specifically expressed in skeletal muscle. CSRP3 is critical in maintaining the structure and function of normal muscle. To investigate the mechanism of disease in CSRP3 myopathy, we performed siRNA-mediated CSRP3 knockdown in chicken primary myoblasts. CSRP3 silencing resulted in the down-regulation of the expression of myogenic genes and the up-regulation of atrophy-related gene expressions. We found that CSRP3 interacted with LC3 protein to promote the formation of autophagosomes during autophagy. CSRP3-silencing impaired myoblast autophagy, as evidenced by inhibited autophagy-related ATG5 and ATG7 mRNA expression levels, and inhibited LC3II and Beclin-1 protein accumulation. In addition, impaired autophagy in CSRP3-silenced cells resulted in increased sensitivity to apoptosis cell death. CSRP3-silenced cells also showed increased caspase-3 and caspase-9 cleavage. Moreover, apoptosis induced by CSRP3 silencing was alleviated after autophagy activation. Together, these results indicate that CSRP3 promotes the correct formation of autophagosomes through its interaction with LC3 protein, which has an important role in skeletal muscle remodeling and maintenance.
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6
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Kalozoumi G, Kel-Margoulis O, Vafiadaki E, Greenberg D, Bernard H, Soreq H, Depaulis A, Sanoudou D. Glial responses during epileptogenesis in Mus musculus point to potential therapeutic targets. PLoS One 2018; 13:e0201742. [PMID: 30114263 PMCID: PMC6095496 DOI: 10.1371/journal.pone.0201742] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 07/21/2018] [Indexed: 01/21/2023] Open
Abstract
The Mesio-Temporal Lobe Epilepsy syndrome is the most common form of intractable epilepsy. It is characterized by recurrence of focal seizures and is often associated with hippocampal sclerosis and drug resistance. We aimed to characterize the molecular changes occurring during the initial stages of epileptogenesis in search of new therapeutic targets for Mesio-Temporal Lobe Epilepsy. We used a mouse model obtained by intra-hippocampal microinjection of kainate and performed hippocampal whole genome expression analysis at 6h, 12h and 24h post-injection, followed by multilevel bioinformatics analysis. We report significant changes in immune and inflammatory responses, neuronal network reorganization processes and glial functions, predominantly initiated during status epilepticus at 12h and persistent after the end of status epilepticus at 24h post-kainate. Upstream regulator analysis highlighted Cyba, Cybb and Vim as central regulators of multiple overexpressed genes implicated in glial responses at 24h. In silico microRNA analysis indicated that miR-9, miR-19b, miR-129, and miR-223 may regulate the expression of glial-associated genes at 24h. Our data support the hypothesis that glial-mediated inflammatory response holds a key role during epileptogenesis, and that microglial cells may participate in the initial process of epileptogenesis through increased ROS production via the NOX complex.
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Affiliation(s)
- Georgia Kalozoumi
- Clinical Genomics and Pharmacogenomics Unit, 4 Department of Internal Medicine, Attikon Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | | | - Elizabeth Vafiadaki
- Molecular Biology Division, Biomedical Research Foundation of the Academy of Athens, Athens, Greece
| | - David Greenberg
- The Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | | | - Hermona Soreq
- The Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Antoine Depaulis
- INSERM, Grenoble, France
- Univ. Grenoble Alpes, Grenoble Institut des Neurosciences, Grenoble, France
- CHU de Grenoble, Hôpital Michallon, Grenoble, France
| | - Despina Sanoudou
- Clinical Genomics and Pharmacogenomics Unit, 4 Department of Internal Medicine, Attikon Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
- Molecular Biology Division, Biomedical Research Foundation of the Academy of Athens, Athens, Greece
- * E-mail:
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7
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Muscle Lim Protein and myosin binding protein C form a complex regulating muscle differentiation. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2017; 1864:2308-2321. [DOI: 10.1016/j.bbamcr.2017.08.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 08/09/2017] [Accepted: 08/30/2017] [Indexed: 01/10/2023]
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8
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Madan A, Thimmaiya D, Franco-Cea A, Aiyaz M, Kumar P, Sparrow JC, Nongthomba U. Transcriptome analysis of IFM-specific actin and myosin nulls in Drosophila melanogaster unravels lesion-specific expression blueprints across muscle mutations. Gene 2017; 631:16-28. [PMID: 28739398 DOI: 10.1016/j.gene.2017.07.061] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 06/20/2017] [Accepted: 07/20/2017] [Indexed: 12/13/2022]
Abstract
Muscle contraction is a highly fine-tuned process that requires the precise and timely construction of large protein sub-assemblies to form sarcomeres. Mutations in many genes encoding constituent proteins of this macromolecular machine result in defective functioning of the muscle tissue. However, the pathways underlying muscle degeneration, and manifestation of myopathy phenotypes are not well understood. In this study, we explored transcriptional alterations that ensue from the absence of the two major muscle proteins - myosin and actin - using the Drosophila indirect flight muscles. Our aim was to understand how the muscle tissue responds as a whole to the absence of either of the major scaffold proteins, whether the responses are generic to the tissue; or unique to the thick versus thin filament systems. Our results indicated that muscles respond by altering gene transcriptional levels in multiple systems active in muscle remodelling, protein degradation and heat shock responses. However, there were some responses that were filament-specific signatures of muscle degeneration, like immune responses, metabolic alterations and alterations in expression of muscle structural genes and mitochondrial ribosomal genes. These general and filament-specific changes in gene expression may be of relevance to human myopathies.
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Affiliation(s)
- Aditi Madan
- Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore 560 012, India.
| | - Divesh Thimmaiya
- Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore 560 012, India
| | - Ari Franco-Cea
- Department of Biology, University of York, York YO10 5DD, United Kingdom.
| | - Mohammed Aiyaz
- Genotypic Technology Pvt. Ltd., Bangalore 560 094, India.
| | - Prabodh Kumar
- Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore 560 012, India.
| | - John C Sparrow
- Department of Biology, University of York, York YO10 5DD, United Kingdom.
| | - Upendra Nongthomba
- Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore 560 012, India.
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9
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Abstract
Cardiac and skeletal striated muscles are intricately designed machines responsible for muscle contraction. Coordination of the basic contractile unit, the sarcomere, and the complex cytoskeletal networks are critical for contractile activity. The sarcomere is comprised of precisely organized individual filament systems that include thin (actin), thick (myosin), titin, and nebulin. Connecting the sarcomere to other organelles (e.g., mitochondria and nucleus) and serving as the scaffold to maintain cellular integrity are the intermediate filaments. The costamere, on the other hand, tethers the sarcomere to the cell membrane. Unique structures like the intercalated disc in cardiac muscle and the myotendinous junction in skeletal muscle help synchronize and transmit force. Intense investigation has been done on many of the proteins that make up these cytoskeletal assemblies. Yet the details of their function and how they interconnect have just started to be elucidated. A vast number of human myopathies are contributed to mutations in muscle proteins; thus understanding their basic function provides a mechanistic understanding of muscle disorders. In this review, we highlight the components of striated muscle with respect to their interactions, signaling pathways, functions, and connections to disease. © 2017 American Physiological Society. Compr Physiol 7:891-944, 2017.
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Affiliation(s)
- Christine A Henderson
- Department of Cellular and Molecular Medicine, The University of Arizona, Tucson, Arizona, USA.,Sarver Molecular Cardiovascular Research Program, The University of Arizona, Tucson, Arizona, USA
| | - Christopher G Gomez
- Department of Cellular and Molecular Medicine, The University of Arizona, Tucson, Arizona, USA.,Sarver Molecular Cardiovascular Research Program, The University of Arizona, Tucson, Arizona, USA
| | - Stefanie M Novak
- Department of Cellular and Molecular Medicine, The University of Arizona, Tucson, Arizona, USA.,Sarver Molecular Cardiovascular Research Program, The University of Arizona, Tucson, Arizona, USA
| | - Lei Mi-Mi
- Department of Cellular and Molecular Medicine, The University of Arizona, Tucson, Arizona, USA.,Sarver Molecular Cardiovascular Research Program, The University of Arizona, Tucson, Arizona, USA
| | - Carol C Gregorio
- Department of Cellular and Molecular Medicine, The University of Arizona, Tucson, Arizona, USA.,Sarver Molecular Cardiovascular Research Program, The University of Arizona, Tucson, Arizona, USA
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10
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Jungbluth H, Ochala J, Treves S, Gautel M. Current and future therapeutic approaches to the congenital myopathies. Semin Cell Dev Biol 2016; 64:191-200. [PMID: 27515125 DOI: 10.1016/j.semcdb.2016.08.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 08/04/2016] [Accepted: 08/08/2016] [Indexed: 12/14/2022]
Abstract
The congenital myopathies - including Central Core Disease (CCD), Multi-minicore Disease (MmD), Centronuclear Myopathy (CNM), Nemaline Myopathy (NM) and Congenital Fibre Type Disproportion (CFTD) - are a genetically heterogeneous group of early-onset neuromuscular conditions characterized by distinct histopathological features, and associated with a substantial individual and societal disease burden. Appropriate supportive management has substantially improved patient morbidity and mortality but there is currently no cure. Recent years have seen an exponential increase in the genetic and molecular understanding of these conditions, leading to the identification of underlying defects in proteins involved in calcium homeostasis and excitation-contraction coupling, thick/thin filament assembly and function, redox regulation, membrane trafficking and/or autophagic pathways. Based on these findings, specific therapies are currently being developed, or are already approaching the clinical trial stage. Despite undeniable progress, therapy development faces considerable challenges, considering the rarity and diversity of specific conditions, and the size and complexity of some of the genes and proteins involved. The present review will summarize the key genetic, histopathological and clinical features of specific congenital myopathies, and outline therapies already available or currently being developed in the context of known pathogenic mechanisms. The relevance of newly discovered molecular mechanisms and novel gene editing strategies for future therapy development will be discussed.
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Affiliation(s)
- Heinz Jungbluth
- Department of Paediatric Neurology, Neuromuscular Service, Evelina's Children Hospital, Guy's & St. Thomas' Hospital NHS Foundation Trust, London, United Kingdom; Randall Division for Cell and Molecular Biophysics, Muscle Signalling Section Biophysics and Cardiovascular Division, King's College BHF Centre of Research Excellence, United Kingdom; Department of Basic and Clinical Neuroscience, IoPPN, King's College, London, United Kingdom.
| | - Julien Ochala
- Centre of Human and Aerospace Physiological Sciences, King's College London, United Kingdom
| | - Susan Treves
- Departments of Biomedicine and Anaesthesia, Basel University Hospital, 4031 Basel, Switzerland
| | - Mathias Gautel
- Randall Division for Cell and Molecular Biophysics, Muscle Signalling Section Biophysics and Cardiovascular Division, King's College BHF Centre of Research Excellence, United Kingdom
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11
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Quintana MT, Parry TL, He J, Yates CC, Sidorova TN, Murray KT, Bain JR, Newgard CB, Muehlbauer MJ, Eaton SC, Hishiya A, Takayama S, Willis MS. Cardiomyocyte-Specific Human Bcl2-Associated Anthanogene 3 P209L Expression Induces Mitochondrial Fragmentation, Bcl2-Associated Anthanogene 3 Haploinsufficiency, and Activates p38 Signaling. THE AMERICAN JOURNAL OF PATHOLOGY 2016; 186:1989-2007. [PMID: 27321750 DOI: 10.1016/j.ajpath.2016.03.017] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Revised: 02/20/2016] [Accepted: 03/17/2016] [Indexed: 12/24/2022]
Abstract
The Bcl2-associated anthanogene (BAG) 3 protein is a member of the BAG family of cochaperones, which supports multiple critical cellular processes, including critical structural roles supporting desmin and interactions with heat shock proteins and ubiquitin ligases intimately involved in protein quality control. The missense mutation P209L in exon 3 results in a primarily cardiac phenotype leading to skeletal muscle and cardiac complications. At least 10 other Bag3 mutations have been reported, nine resulting in a dilated cardiomyopathy for which no specific therapy is available. We generated αMHC-human Bag3 P209L transgenic mice and characterized the progressive cardiac phenotype in vivo to investigate its utility in modeling human disease, understand the underlying molecular mechanisms, and identify potential therapeutic targets. We identified a progressive heart failure by echocardiography and Doppler analysis and the presence of pre-amyloid oligomers at 1 year. Paralleling the pathogenesis of neurodegenerative diseases (eg, Parkinson disease), pre-amyloid oligomers-associated alterations in cardiac mitochondrial dynamics, haploinsufficiency of wild-type BAG3, and activation of p38 signaling were identified. Unexpectedly, increased numbers of activated cardiac fibroblasts were identified in Bag3 P209L Tg+ hearts without increased fibrosis. Together, these findings point to a previously undescribed therapeutic target that may have application to mutation-induced myofibrillar myopathies as well as other common causes of heart failure that commonly harbor misfolded proteins.
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Affiliation(s)
- Megan T Quintana
- Department of Surgery, University of North Carolina, Chapel Hill, North Carolina
| | - Traci L Parry
- McAllister Heart Institute, University of North Carolina, Chapel Hill, North Carolina
| | - Jun He
- General Hospital of Ningxia Medical University, Yinchuan, Ningxia, People's Republic of China
| | - Cecelia C Yates
- Department of Health Promotions and Development, School of Nursing, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Tatiana N Sidorova
- Departments of Medicine and Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Katherine T Murray
- Departments of Medicine and Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - James R Bain
- Sarah W. Stedman Nutrition and Metabolism Center, Duke Molecular Physiology Institute, Duke University Medical Center, Durham, North Carolina; Division of Endocrinology, Metabolism, and Nutrition, Department of Medicine, Duke University Medical Center, Durham, North Carolina
| | - Christopher B Newgard
- Sarah W. Stedman Nutrition and Metabolism Center, Duke Molecular Physiology Institute, Duke University Medical Center, Durham, North Carolina; Division of Endocrinology, Metabolism, and Nutrition, Department of Medicine, Duke University Medical Center, Durham, North Carolina
| | - Michael J Muehlbauer
- Sarah W. Stedman Nutrition and Metabolism Center, Duke Molecular Physiology Institute, Duke University Medical Center, Durham, North Carolina
| | - Samuel C Eaton
- Department of Pharmacology, University of North Carolina, Chapel Hill, North Carolina
| | | | - Shin Takayama
- Department of Pathology, Boston University, Boston, Massachusetts
| | - Monte S Willis
- McAllister Heart Institute, University of North Carolina, Chapel Hill, North Carolina; Department of Pharmacology, University of North Carolina, Chapel Hill, North Carolina; Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, North Carolina.
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12
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Molecular cloning, characterization and tissue specificity of the expression of the ovine CSRP2 and CSRP3 genes from Small-tail Han sheep (Ovis aries). Gene 2016; 580:47-57. [DOI: 10.1016/j.gene.2016.01.021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Revised: 12/22/2015] [Accepted: 01/04/2016] [Indexed: 11/19/2022]
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13
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Rashid MM, Runci A, Russo MA, Tafani M. Muscle Lim Protein (MLP)/CSRP3 at the crossroad between mechanotransduction and autophagy. Cell Death Dis 2015; 6:e1940. [PMID: 26492373 PMCID: PMC4632324 DOI: 10.1038/cddis.2015.308] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- M M Rashid
- Department of Experimental Medicine, University of Rome, Sapienza, Rome, Italy
| | - A Runci
- Department of Experimental Medicine, University of Rome, Sapienza, Rome, Italy
| | - M A Russo
- Department of Cellular and Molecular Pathology, IRCCS San Raffaele, Rome, Italy
| | - M Tafani
- Department of Experimental Medicine, University of Rome, Sapienza, Rome, Italy
- Department of Cellular and Molecular Pathology, IRCCS San Raffaele, Rome, Italy
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14
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Vafiadaki E, Arvanitis DA, Sanoudou D. Muscle LIM Protein: Master regulator of cardiac and skeletal muscle functions. Gene 2015; 566:1-7. [PMID: 25936993 PMCID: PMC6660132 DOI: 10.1016/j.gene.2015.04.077] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Revised: 04/21/2015] [Accepted: 04/27/2015] [Indexed: 12/17/2022]
Abstract
Muscle LIM Protein (MLP) has emerged as a key regulator of striated muscle physiology and pathophysiology. Mutations in cysteine and glycine-rich protein 3 (CSRP3), the gene encoding MLP, are causative of human cardiomyopathies, whereas altered expression patterns are observed in human failing heart and skeletal myopathies. In vitro and in vivo evidences reveal a complex and diverse functional role of MLP in striated muscle, which is determined by its multiple interacting partners and subcellular distribution. Experimental evidence suggests that MLP is implicated in both myogenic differentiation and myocyte cytoarchitecture, although the full spectrum of its intracellular roles still unfolds.
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Affiliation(s)
- Elizabeth Vafiadaki
- Molecular Biology Division, Biomedical Research Foundation of the Academy of Athens, Greece
| | - Demetrios A Arvanitis
- Molecular Biology Division, Biomedical Research Foundation of the Academy of Athens, Greece
| | - Despina Sanoudou
- Molecular Biology Division, Biomedical Research Foundation of the Academy of Athens, Greece; 4th Department of Internal Medicine, Attikon University Hospital, Medical School, National and Kapodistrian University of Athens, Greece.
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15
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Ravenscroft G, Laing NG, Bönnemann CG. Pathophysiological concepts in the congenital myopathies: blurring the boundaries, sharpening the focus. ACTA ACUST UNITED AC 2014; 138:246-68. [PMID: 25552303 DOI: 10.1093/brain/awu368] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The congenital myopathies are a diverse group of genetic skeletal muscle diseases, which typically present at birth or in early infancy. There are multiple modes of inheritance and degrees of severity (ranging from foetal akinesia, through lethality in the newborn period to milder early and later onset cases). Classically, the congenital myopathies are defined by skeletal muscle dysfunction and a non-dystrophic muscle biopsy with the presence of one or more characteristic histological features. However, mutations in multiple different genes can cause the same pathology and mutations in the same gene can cause multiple different pathologies. This is becoming ever more apparent now that, with the increasing use of next generation sequencing, a genetic diagnosis is achieved for a greater number of patients. Thus, considerable genetic and pathological overlap is emerging, blurring the classically established boundaries. At the same time, some of the pathophysiological concepts underlying the congenital myopathies are moving into sharper focus. Here we explore whether our emerging understanding of disease pathogenesis and underlying pathophysiological mechanisms, rather than a strictly gene-centric approach, will provide grounds for a different and perhaps complementary grouping of the congenital myopathies, that at the same time could help instil the development of shared potential therapeutic approaches. Stemming from recent advances in the congenital myopathy field, five key pathophysiology themes have emerged: defects in (i) sarcolemmal and intracellular membrane remodelling and excitation-contraction coupling; (ii) mitochondrial distribution and function; (iii) myofibrillar force generation; (iv) atrophy; and (v) autophagy. Based on numerous emerging lines of evidence from recent studies in cell lines and patient tissues, mouse models and zebrafish highlighting these unifying pathophysiological themes, here we review the congenital myopathies in relation to these emerging pathophysiological concepts, highlighting both areas of overlap between established entities, as well as areas of distinction within single gene disorders.
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Affiliation(s)
- Gianina Ravenscroft
- 1 Harry Perkins Institute of Medical Research, Centre for Medical Research, University of Western Australia, Nedlands, Western Australia, Australia
| | - Nigel G Laing
- 1 Harry Perkins Institute of Medical Research, Centre for Medical Research, University of Western Australia, Nedlands, Western Australia, Australia
| | - Carsten G Bönnemann
- 2 National Institute of Neurological Disorders and Stroke/NIH, Porter Neuroscience Research Centre, Bethesda, MD, USA
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16
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Alterations at the cross-bridge level are associated with a paradoxical gain of muscle function in vivo in a mouse model of nemaline myopathy. PLoS One 2014; 9:e109066. [PMID: 25268244 PMCID: PMC4182639 DOI: 10.1371/journal.pone.0109066] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Accepted: 09/09/2014] [Indexed: 11/29/2022] Open
Abstract
Nemaline myopathy is the most common disease entity among non-dystrophic skeletal muscle congenital diseases. The first disease causing mutation (Met9Arg) was identified in the gene encoding α-tropomyosinslow gene (TPM3). Considering the conflicting findings of the previous studies on the transgenic (Tg) mice carrying the TPM3Met9Arg mutation, we investigated carefully the effect of the Met9Arg mutation in 8–9 month-old Tg(TPM3)Met9Arg mice on muscle function using a multiscale methodological approach including skinned muscle fibers analysis and invivo investigations by magnetic resonance imaging and 31-phosphorus magnetic resonance spectroscopy. While invitro maximal force production was reduced in Tg(TPM3)Met9Arg mice as compared to controls, invivo measurements revealed an improved mechanical performance in the transgenic mice as compared to the former. The reduced invitro muscle force might be related to alterations occuring at the cross-bridges level with muscle-specific underlying mechanisms. In vivo muscle improvement was not associated with any changes in either muscle volume or energy metabolism. Our findings indicate that TPM3(Met9Arg) mutation leads to a mild muscle weakness invitro related to an alteration at the cross-bridges level and a paradoxical gain of muscle function invivo. These results clearly point out that invitro alterations are muscle-dependent and do not necessarily translate into similar changes invivo.
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17
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Vafiadaki E, Arvanitis DA, Papalouka V, Terzis G, Roumeliotis TI, Spengos K, Garbis SD, Manta P, Kranias EG, Sanoudou D. Muscle lim protein isoform negatively regulates striated muscle actin dynamics and differentiation. FEBS J 2014; 281:3261-79. [PMID: 24860983 DOI: 10.1111/febs.12859] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Revised: 05/14/2014] [Accepted: 05/22/2014] [Indexed: 11/28/2022]
Abstract
Muscle lim protein (MLP) has emerged as a critical regulator of striated muscle physiology and pathophysiology. Mutations in cysteine and glycine-rich protein 3 (CSRP3), the gene encoding MLP, have been directly associated with human cardiomyopathies, whereas aberrant expression patterns are reported in human cardiac and skeletal muscle diseases. Increasing evidence suggests that MLP has an important role in both myogenic differentiation and myocyte cytoarchitecture, although the full spectrum of its intracellular roles has not been delineated. We report the discovery of an alternative splice variant of MLP, designated as MLP-b, showing distinct expression in neuromuscular disease and direct roles in actin dynamics and muscle differentiation. This novel isoform originates by alternative splicing of exons 3 and 4. At the protein level, it contains the N-terminus first half LIM domain of MLP and a unique sequence of 22 amino acids. Physiologically, it is expressed during early differentiation, whereas its overexpression reduces C2C12 differentiation and myotube formation. This may be mediated through its inhibition of MLP/cofilin-2-mediated F-actin dynamics. In differentiated striated muscles, MLP-b localizes to the sarcomeres and binds directly to Z-disc components, including α-actinin, T-cap and MLP. The findings of the present study unveil a novel player in muscle physiology and pathophysiology that is implicated in myogenesis as a negative regulator of myotube formation, as well as in differentiated striated muscles as a contributor to sarcomeric integrity.
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Affiliation(s)
- Elizabeth Vafiadaki
- Molecular Biology Division, Biomedical Research Foundation of the Academy of Athens, Greece
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18
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Distinct underlying mechanisms of limb and respiratory muscle fiber weaknesses in nemaline myopathy. J Neuropathol Exp Neurol 2013; 72:472-81. [PMID: 23656990 DOI: 10.1097/nen.0b013e318293b1cc] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Nemaline myopathy is the most common congenital myopathy and is caused by mutations in various genes such as ACTA1 (encoding skeletal α-actin). It is associated with limb and respiratory muscle weakness. Despite increasing clinical and scientific interest, the molecular and cellular events leading to such weakness remain unknown, which prevents the development of specific therapeutic interventions. To unravel the potential mechanisms involved, we dissected lower limb and diaphragm muscles from a knock-in mouse model of severe nemaline myopathy expressing the ACTA1 His40Tyr actin mutation found in human patients. We then studied a broad range of structural and functional characteristics assessing single-myofiber contraction, protein expression, and electron microscopy. One of the major findings in the diaphragm was the presence of numerous noncontractile areas (including disrupted sarcomeric structures and nemaline bodies). This greatly reduced the number of functional sarcomeres, decreased the force generation capacity at the muscle fiber level, and likely would contribute to respiratory weakness. In limb muscle, by contrast, there were fewer noncontractile areas and they did not seem to have a major role in the pathogenesis of weakness. These divergent muscle-specific results provide new important insights into the pathophysiology of severe nemaline myopathy and crucial information for future development of therapeutic strategies.
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Clark KA, Kadrmas JL. Drosophila melanogaster muscle LIM protein and alpha-actinin function together to stabilize muscle cytoarchitecture: a potential role for Mlp84B in actin-crosslinking. Cytoskeleton (Hoboken) 2013; 70:304-16. [PMID: 23606669 PMCID: PMC3716849 DOI: 10.1002/cm.21106] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Revised: 03/04/2013] [Accepted: 03/06/2013] [Indexed: 02/06/2023]
Abstract
Stabilization of tissue architecture during development and growth is essential to maintain structural integrity. Because of its contractile nature, muscle is especially susceptible to physiological stresses, and has multiple mechanisms to maintain structural integrity. The Drosophila melanogaster Muscle LIM Protein (MLP), Mlp84B, participates in muscle maintenance, yet its precise mechanism of action is still controversial. Through a candidate approach, we identified α-actinin as a protein that functions with Mlp84B to ensure muscle integrity. α-actinin RNAi animals die primarily as pupae, and Mlp84B RNAi animals are adult viable. RNAi knockdown of Mlp84B and α-actinin together produces synergistic early larval lethality and destabilization of Z-line structures. We recapitulated these phenotypes using combinations of traditional loss-of-function alleles and single-gene RNAi. We observe that Mlp84B induces the formation of actin loops in muscle cell nuclei in the absence of nuclear α-actinin, suggesting Mlp84B has intrinsic actin cross-linking activity, which may complement α-actinin cross-linking activity at sites of actin filament anchorage. These results reveal a molecular mechanism for MLP stabilization of muscle and implicate reduced actin crosslinking as the primary destabilizing defect in MLP-associated cardiomyopathies. Our data support a model in which α-actinin and Mlp84B have important and overlapping functions at sites of actin filament anchorage to preserve muscle structure and function.
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Affiliation(s)
- Kathleen A. Clark
- Huntsman Cancer Institute, University of Utah, Salt Lake City, UT 84112
- Department of Biology, University of Utah, Salt Lake City, UT 84112
- Department of Oncological Sciences, University of Utah, Salt Lake City, UT 84112
| | - Julie L. Kadrmas
- Huntsman Cancer Institute, University of Utah, Salt Lake City, UT 84112
- Department of Oncological Sciences, University of Utah, Salt Lake City, UT 84112
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20
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Gineste C, De Winter JM, Kohl C, Witt CC, Giannesini B, Brohm K, Le Fur Y, Gretz N, Vilmen C, Pecchi E, Jubeau M, Cozzone PJ, Stienen GJM, Granzier H, Labeit S, Ottenheijm CAC, Bendahan D, Gondin J. In vivo and in vitro investigations of heterozygous nebulin knock-out mice disclose a mild skeletal muscle phenotype. Neuromuscul Disord 2013; 23:357-69. [PMID: 23375831 DOI: 10.1016/j.nmd.2012.12.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Revised: 12/07/2012] [Accepted: 12/29/2012] [Indexed: 01/30/2023]
Abstract
Nemaline myopathy is the most common congenital skeletal muscle disease, and mutations in the nebulin gene account for 50% of all cases. Recent studies suggest that the disease severity might be related to the nebulin expression levels. Considering that mutations in the nebulin gene are typically recessive, one would expect that a single functional nebulin allele would maintain nebulin protein expression which would result in preserved skeletal muscle function. We investigated skeletal muscle function of heterozygous nebulin knock-out (i.e., nebulin(+/-)) mice using a multidisciplinary approach including protein and gene expression analysis and combined in vivo and in vitro force measurements. Skeletal muscle anatomy and energy metabolism were studied strictly non-invasively using magnetic resonance imaging and 31P-magnetic resonance spectroscopy. Maximal force production was reduced by around 16% in isolated muscle of nebulin(+/-) mice while in vivo force generating capacity was preserved. Muscle weakness was associated with a shift toward a slower proteomic phenotype, but was not related to nebulin protein deficiency or to an impaired energy metabolism. Further studies would be warranted in order to determine the mechanisms leading to a mild skeletal muscle phenotype resulting from the expression of a single nebulin allele.
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Affiliation(s)
- C Gineste
- Aix-Marseille Université, CRMBM, 13005 Marseille, France
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21
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In vitro culture and induced differentiation of sheep skeletal muscle satellite cells. Cell Biol Int 2012; 36:579-87. [PMID: 22233500 DOI: 10.1042/cbi20110487] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Skeletal muscle satellite cells are adult muscle-derived stem cells receiving increasing attention. Sheep satellite cells have a greater similarity to human satellite cells with regard to metabolism, life span, proliferation and differentiation, than satellite cells of the rat and mouse. We have used 2-step enzymatic digestion and differential adhesion methods to isolate and purify sheep skeletal muscle satellite cells, identified the cells and induced differentiation to examine their pluripotency. The most efficient method for the isolation of sheep skeletal muscle satellite cells was the type I collagenase and trypsin 2-step digestion method, with the best conditions for in vitro culture being in medium containing 20% FBS+10% horse serum. Immunofluorescence staining showed that satellite cells expressed Desmin, α-Sarcomeric Actinin, MyoD1, Myf5 and PAX7. After myogenic induction, multinucleated myotubes formed, as indicated by the expression of MyoG and fast muscle myosin. After osteogenic induction, cells expressed Osteocalcin, with Alizarin Red and ALP (alkaline phosphatase) staining results both being positive. After adipogenic induction, cells expressed PPARγ2 (peroxisome-proliferator-activated receptor γ2) and clear lipid droplets were present around the cells, with Oil Red-O staining giving a positive result. In summary, a successful system has been established for the isolation, purification and identification of sheep skeletal muscle satellite cells.
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22
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Nguyen MAT, Joya JE, Kee AJ, Domazetovska A, Yang N, Hook JW, Lemckert FA, Kettle E, Valova VA, Robinson PJ, North KN, Gunning PW, Mitchell CA, Hardeman EC. Hypertrophy and dietary tyrosine ameliorate the phenotypes of a mouse model of severe nemaline myopathy. ACTA ACUST UNITED AC 2011; 134:3516-29. [PMID: 22067542 DOI: 10.1093/brain/awr274] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Nemaline myopathy, the most common congenital myopathy, is caused by mutations in genes encoding thin filament and thin filament-associated proteins in skeletal muscles. Severely affected patients fail to survive beyond the first year of life due to severe muscle weakness. There are no specific therapies to combat this muscle weakness. We have generated the first knock-in mouse model for severe nemaline myopathy by replacing a normal allele of the α-skeletal actin gene with a mutated form (H40Y), which causes severe nemaline myopathy in humans. The Acta1(H40Y) mouse has severe muscle weakness manifested as shortened lifespan, significant forearm and isolated muscle weakness and decreased mobility. Muscle pathologies present in the human patients (e.g. nemaline rods, fibre atrophy and increase in slow fibres) were detected in the Acta1(H40Y) mouse, indicating that it is an excellent model for severe nemaline myopathy. Mating of the Acta1(H40Y) mouse with hypertrophic four and a half LIM domains protein 1 and insulin-like growth factor-1 transgenic mice models increased forearm strength and mobility, and decreased nemaline pathologies. Dietary L-tyrosine supplements also alleviated the mobility deficit and decreased the chronic repair and nemaline rod pathologies. These results suggest that L-tyrosine may be an effective treatment for muscle weakness and immobility in nemaline myopathy.
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Affiliation(s)
- Mai-Anh T Nguyen
- Neuromuscular and Regenerative Medicine Unit, School of Medical Sciences, University of New South Wales, Kensington, NSW 2052, Australia
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23
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Lennerz JK, Hurov JB, White LS, Lewandowski KT, Prior JL, Planer GJ, Gereau RW, Piwnica-Worms D, Schmidt RE, Piwnica-Worms H. Loss of Par-1a/MARK3/C-TAK1 kinase leads to reduced adiposity, resistance to hepatic steatosis, and defective gluconeogenesis. Mol Cell Biol 2010; 30:5043-56. [PMID: 20733003 PMCID: PMC2953066 DOI: 10.1128/mcb.01472-09] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2009] [Revised: 12/22/2009] [Accepted: 07/29/2010] [Indexed: 12/11/2022] Open
Abstract
Par-1 is an evolutionarily conserved protein kinase required for polarity in worms, flies, frogs, and mammals. The mammalian Par-1 family consists of four members. Knockout studies of mice implicate Par-1b/MARK2/EMK in regulating fertility, immune homeostasis, learning, and memory as well as adiposity, insulin hypersensitivity, and glucose metabolism. Here, we report phenotypes of mice null for a second family member (Par-1a/MARK3/C-TAK1) that exhibit increased energy expenditure, reduced adiposity with unaltered glucose handling, and normal insulin sensitivity. Knockout mice were protected against high-fat diet-induced obesity and displayed attenuated weight gain, complete resistance to hepatic steatosis, and improved glucose handling with decreased insulin secretion. Overnight starvation led to complete hepatic glycogen depletion, associated hypoketotic hypoglycemia, increased hepatocellular autophagy, and increased glycogen synthase levels in Par-1a(-/-) but not in control or Par-1b(-/-) mice. The intercrossing of Par-1a(-/-) with Par-1b(-/-) mice revealed that at least one of the four alleles is necessary for embryonic survival. The severity of phenotypes followed a rank order, whereby the loss of one Par-1b allele in Par-1a(-/-) mice conveyed milder phenotypes than the loss of one Par-1a allele in Par-1b(-/-) mice. Thus, although Par-1a and Par-1b can compensate for one another during embryogenesis, their individual disruption gives rise to distinct metabolic phenotypes in adult mice.
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Affiliation(s)
- Jochen K. Lennerz
- Department of Pathology and Immunology, Department of Cell Biology and Physiology, Molecular Imaging Center, Mallinckrodt Institute of Radiology, Department of Neurology, Neuromuscular Laboratory, Washington University Pain Center and Department of Anesthesiology, Department of Developmental Biology, Department of Internal Medicine, BRIGHT Institute, Washington University School of Medicine, St. Louis, Missouri 63110, Howard Hughes Medical Institute, Chevy Chase, Maryland 20815
| | - Jonathan B. Hurov
- Department of Pathology and Immunology, Department of Cell Biology and Physiology, Molecular Imaging Center, Mallinckrodt Institute of Radiology, Department of Neurology, Neuromuscular Laboratory, Washington University Pain Center and Department of Anesthesiology, Department of Developmental Biology, Department of Internal Medicine, BRIGHT Institute, Washington University School of Medicine, St. Louis, Missouri 63110, Howard Hughes Medical Institute, Chevy Chase, Maryland 20815
| | - Lynn S. White
- Department of Pathology and Immunology, Department of Cell Biology and Physiology, Molecular Imaging Center, Mallinckrodt Institute of Radiology, Department of Neurology, Neuromuscular Laboratory, Washington University Pain Center and Department of Anesthesiology, Department of Developmental Biology, Department of Internal Medicine, BRIGHT Institute, Washington University School of Medicine, St. Louis, Missouri 63110, Howard Hughes Medical Institute, Chevy Chase, Maryland 20815
| | - Katherine T. Lewandowski
- Department of Pathology and Immunology, Department of Cell Biology and Physiology, Molecular Imaging Center, Mallinckrodt Institute of Radiology, Department of Neurology, Neuromuscular Laboratory, Washington University Pain Center and Department of Anesthesiology, Department of Developmental Biology, Department of Internal Medicine, BRIGHT Institute, Washington University School of Medicine, St. Louis, Missouri 63110, Howard Hughes Medical Institute, Chevy Chase, Maryland 20815
| | - Julie L. Prior
- Department of Pathology and Immunology, Department of Cell Biology and Physiology, Molecular Imaging Center, Mallinckrodt Institute of Radiology, Department of Neurology, Neuromuscular Laboratory, Washington University Pain Center and Department of Anesthesiology, Department of Developmental Biology, Department of Internal Medicine, BRIGHT Institute, Washington University School of Medicine, St. Louis, Missouri 63110, Howard Hughes Medical Institute, Chevy Chase, Maryland 20815
| | - G. James Planer
- Department of Pathology and Immunology, Department of Cell Biology and Physiology, Molecular Imaging Center, Mallinckrodt Institute of Radiology, Department of Neurology, Neuromuscular Laboratory, Washington University Pain Center and Department of Anesthesiology, Department of Developmental Biology, Department of Internal Medicine, BRIGHT Institute, Washington University School of Medicine, St. Louis, Missouri 63110, Howard Hughes Medical Institute, Chevy Chase, Maryland 20815
| | - Robert W. Gereau
- Department of Pathology and Immunology, Department of Cell Biology and Physiology, Molecular Imaging Center, Mallinckrodt Institute of Radiology, Department of Neurology, Neuromuscular Laboratory, Washington University Pain Center and Department of Anesthesiology, Department of Developmental Biology, Department of Internal Medicine, BRIGHT Institute, Washington University School of Medicine, St. Louis, Missouri 63110, Howard Hughes Medical Institute, Chevy Chase, Maryland 20815
| | - David Piwnica-Worms
- Department of Pathology and Immunology, Department of Cell Biology and Physiology, Molecular Imaging Center, Mallinckrodt Institute of Radiology, Department of Neurology, Neuromuscular Laboratory, Washington University Pain Center and Department of Anesthesiology, Department of Developmental Biology, Department of Internal Medicine, BRIGHT Institute, Washington University School of Medicine, St. Louis, Missouri 63110, Howard Hughes Medical Institute, Chevy Chase, Maryland 20815
| | - Robert E. Schmidt
- Department of Pathology and Immunology, Department of Cell Biology and Physiology, Molecular Imaging Center, Mallinckrodt Institute of Radiology, Department of Neurology, Neuromuscular Laboratory, Washington University Pain Center and Department of Anesthesiology, Department of Developmental Biology, Department of Internal Medicine, BRIGHT Institute, Washington University School of Medicine, St. Louis, Missouri 63110, Howard Hughes Medical Institute, Chevy Chase, Maryland 20815
| | - Helen Piwnica-Worms
- Department of Pathology and Immunology, Department of Cell Biology and Physiology, Molecular Imaging Center, Mallinckrodt Institute of Radiology, Department of Neurology, Neuromuscular Laboratory, Washington University Pain Center and Department of Anesthesiology, Department of Developmental Biology, Department of Internal Medicine, BRIGHT Institute, Washington University School of Medicine, St. Louis, Missouri 63110, Howard Hughes Medical Institute, Chevy Chase, Maryland 20815
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Hishiya A, Kitazawa T, Takayama S. BAG3 and Hsc70 interact with actin capping protein CapZ to maintain myofibrillar integrity under mechanical stress. Circ Res 2010; 107:1220-31. [PMID: 20884878 DOI: 10.1161/circresaha.110.225649] [Citation(s) in RCA: 117] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
RATIONALE A homozygous disruption or genetic mutation of the bag3 gene, a member of the Bcl-2-associated athanogene (BAG) family proteins, causes cardiomyopathy and myofibrillar myopathy that is characterized by myofibril and Z-disc disruption. However, the detailed disease mechanism is not yet fully understood. OBJECTIVE bag3(-/-) mice exhibit differences in the extent of muscle degeneration between muscle groups with muscles experiencing the most usage degenerating at an accelerated rate. Usage-dependent muscle degeneration suggests a role for BAG3 in supporting cytoskeletal connections between the Z-disc and myofibrils under mechanical stress. The mechanism by which myofibrillar structure is maintained under mechanical stress remains unclear. The purpose of the study is to clarify the detailed molecular mechanism of BAG3-mediated muscle maintenance under mechanical stress. METHODS AND RESULTS To address the question of whether bag3 gene knockdown induces myofibrillar disorganization caused by mechanical stress, in vitro mechanical stretch experiments using rat neonatal cardiomyocytes and a short hairpin RNA-mediated gene knockdown system of the bag3 gene were performed. As expected, mechanical stretch rapidly disrupts myofibril structures in bag3 knockdown cardiomyocytes. BAG3 regulates the structural stability of F-actin through the actin capping protein, CapZβ1, by promoting association between Hsc70 and CapZβ1. BAG3 facilitates the distribution of CapZβ1 to the proper location, and dysfunction of BAG3 induces CapZ ubiquitin-proteasome-mediated degradation. Inhibition of CapZβ1 function by overexpressing CapZβ2 increased myofibril vulnerability and fragmentation under mechanical stress. On the other hand, overexpression of CapZβ1 inhibits myofibrillar disruption in bag3 knockdown cells under mechanical stress. As a result, heart muscle isolated from bag3(-/-) mice exhibited myofibrillar degeneration and lost contractile activity after caffeine contraction. CONCLUSIONS These results suggest novel roles for BAG3 and Hsc70 in stabilizing myofibril structure and inhibiting myofibrillar degeneration in response to mechanical stress. These proteins are possible targets for further research to identify therapies for myofibrillar myopathy or other degenerative diseases.
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Affiliation(s)
- Akinori Hishiya
- Boston Biomedical Research Institute, Watertown, MA 02472, USA
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25
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van Lunteren E, Spiegler S, Moyer M. Differential expression of lipid and carbohydrate metabolism genes in upper airway versus diaphragm muscle. Sleep 2010; 33:363-70. [PMID: 20337195 DOI: 10.1093/sleep/33.3.363] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
STUDY OBJECTIVES Contractile properties of upper airway muscles influence upper airway patency, an issue of particular importance for subjects with obstructive sleep apnea. Expression of genes related to cellular energetics is, in turn, critical for the maintenance of contractile integrity over time during repetitive activation. We tested the hypothesis that sternohyoid has lower expression of genes related to lipid and carbohydrate energetic pathways than the diaphragm. METHODS Sternohyoid and diaphragm from normal adult rats were examined with gene expression arrays. Analysis focused on genes belonging to Gene Ontology (GO) groups carbohydrate metabolism and lipid metabolism. RESULTS There were 433 genes with at least +/- 2-fold significant differential expression between sternohyoid and diaphragm, of which 192 had sternohyoid > diaphragm and 241 had diaphragm > sternohyoid expression. Among genes with higher sternohyoid expression, there was over-representation of the GO group carbohydrate metabolism (P = 0.0053, n = 13 genes, range of differential expression 2.1- to 6.2-fold) but not lipid metabolism (P = 0.44). Conversely, among genes with higher diaphragm expression, there was over-representation of the GO group lipid metabolism (P = 0.0000065, n = 32 genes, range of differential expression 2.0- to 37.9-fold) but not carbohydrate metabolism (P = 0.23). Nineteen genes with diaphragm > sternohyoid expression were related to fatty acid metabolism (P = 0.000000058), in particular fatty acid beta oxidation and biosynthesis in the mitochondria. CONCLUSIONS Sternohyoid has much lower gene expression than diaphragm for mitochondrial enzymes that participate in fatty acid oxidation and biosynthesis. This likely contributes to the lower fatigue resistance of pharyngeal upper airway muscles compared with the diaphragm.
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Affiliation(s)
- Erik van Lunteren
- Pulmonary, Critical Care and Sleep Division, Department of Medicine, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH 44106, USA.
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26
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Tondeleir D, Vandamme D, Vandekerckhove J, Ampe C, Lambrechts A. Actin isoform expression patterns during mammalian development and in pathology: insights from mouse models. ACTA ACUST UNITED AC 2009; 66:798-815. [PMID: 19296487 DOI: 10.1002/cm.20350] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The dynamic actin cytoskeleton, consisting of six actin isoforms in mammals and a variety of actin binding proteins is essential for all developmental processes and for the viability of the adult organism. Actin isoform specific functions have been proposed for muscle contraction, cell migration, endo- and exocytosis and maintaining cell shape. However, these specific functions for each of the actin isoforms during development are not well understood. Based on transgenic mouse models, we will discuss the expression patterns of the six conventional actin isoforms in mammals during development and adult life. Ablation of actin genes usually leads to lethality and affects expression of other actin isoforms at the cell or tissue level. A good knowledge of their expression and functions will contribute to fully understand severe phenotypes or diseases caused by mutations in actin isoforms.
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Affiliation(s)
- Davina Tondeleir
- Department of Medical Protein Research, Flanders Interuniversity Institute for Biotechnology (VIB), Albert Baertsoenkaai 3, Ghent, Belgium
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Muscle LIM protein interacts with cofilin 2 and regulates F-actin dynamics in cardiac and skeletal muscle. Mol Cell Biol 2009; 29:6046-58. [PMID: 19752190 DOI: 10.1128/mcb.00654-09] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The muscle LIM protein (MLP) and cofilin 2 (CFL2) are important regulators of striated myocyte function. Mutations in the corresponding genes have been directly associated with severe human cardiac and skeletal myopathies, and aberrant expression patterns have often been observed in affected muscles. Herein, we have investigated whether MLP and CFL2 are involved in common molecular mechanisms, which would promote our understanding of disease pathogenesis. We have shown for the first time, using a range of biochemical and immunohistochemical methods, that MLP binds directly to CFL2 in human cardiac and skeletal muscles. The interaction involves the inter-LIM domain, amino acids 94 to 105, of MLP and the amino-terminal domain, amino acids 1 to 105, of CFL2, which includes part of the actin depolymerization domain. The MLP/CFL2 complex is stronger in moderately acidic (pH 6.8) environments and upon CFL2 phosphorylation, while it is independent of Ca(2+) levels. This interaction has direct implications in actin cytoskeleton dynamics in regulating CFL2-dependent F-actin depolymerization, with maximal depolymerization enhancement at an MLP/CFL2 molecular ratio of 2:1. Deregulation of this interaction by intracellular pH variations, CFL2 phosphorylation, MLP or CFL2 gene mutations, or expression changes, as observed in a range of cardiac and skeletal myopathies, could impair F-actin depolymerization, leading to sarcomere dysfunction and disease.
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Vandamme D, Lambert E, Waterschoot D, Cognard C, Vandekerckhove J, Ampe C, Constantin B, Rommelaere H. alpha-Skeletal muscle actin nemaline myopathy mutants cause cell death in cultured muscle cells. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2009; 1793:1259-71. [PMID: 19393268 DOI: 10.1016/j.bbamcr.2009.04.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2008] [Revised: 03/24/2009] [Accepted: 04/14/2009] [Indexed: 11/24/2022]
Abstract
Nemaline myopathy is a neuromuscular disorder, characterized by muscle weakness and hypotonia and is, in 20% of the cases, caused by mutations in the gene encoding alpha-skeletal muscle actin, ACTA1. It is a heterogeneous disease with various clinical phenotypes and severities. In patients the ultrastructure of muscle cells is often disturbed by nemaline rods and it is thought this is the cause for muscle weakness. To search for possible defects during muscle cell differentiation we expressed alpha-actin mutants in myoblasts and allowed these cells to differentiate into myotubes. Surprisingly, we observed two striking new phenotypes in differentiating myoblasts: rounding up of cells and bleb formation, two features reminiscent of apoptosis. Indeed expression of these mutants induced cell death with apoptotic features in muscle cell culture, using AIF and endonuclease G, in a caspase-independent but calpain-dependent pathway. This is the first report on a common cellular defect induced by NM causing actin mutants, independent of their biochemical phenotypes or rod and aggregate formation capacity. These data suggest that lack of type II fibers or atrophy observed in nemaline myopathy patients may be also due to an increased number of dying muscle cells.
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Affiliation(s)
- Drieke Vandamme
- Department of Biochemistry, Ghent University, A. Baertsoenkaai 3, B-9000, Gent, Belgium
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Phenotypes induced by NM causing alpha-skeletal muscle actin mutants in fibroblasts, Sol 8 myoblasts and myotubes. BMC Res Notes 2009; 2:40. [PMID: 19284548 PMCID: PMC2657152 DOI: 10.1186/1756-0500-2-40] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2009] [Accepted: 03/10/2009] [Indexed: 11/15/2022] Open
Abstract
Background Nemaline myopathy is a neuromuscular disorder characterized by the presence of nemaline bodies in patient muscles. 20% of the cases are associated with α-skeletal muscle actin mutations. We previously showed that actin mutations can cause four different biochemical phenotypes and that expression of NM associated actin mutants in fibroblasts, myoblasts and myotubes induces a range of cellular defects. Findings We conducted the same biochemical experiments for twelve new actin mutants associated with nemaline myopathy. We observed folding and polymerization defects. Immunostainings of these and eight other mutants in transfected cells revealed typical cellular defects such as nemaline rods or aggregates, decreased incorporation in F-actin structures, membrane blebbing, the formation of thickened actin fibres and cell membrane blebbing in myotubes. Conclusion Our results confirm that NM associated α-actin mutations induce a range of defects at the biochemical level as well as in cultured fibroblasts and muscle cells.
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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.
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Garvey SM, Liu Y, Miller SE, Hauser MA. Myotilin overexpression enhances myopathology in the LGMD1A mouse model. Muscle Nerve 2008; 37:663-7. [PMID: 18335471 DOI: 10.1002/mus.20994] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Missense mutations in the myotilin gene cause limb-girdle muscular dystrophy type 1A (LGMD1A). We set out to examine the effect of overexpression of wild-type myotilin in an LGMD1A mouse model by crossing wild-type and mutant transgenic mice. Compared to single-transgenic mutant mice, double-transgenic mice overexpressing myotilin showed more severe muscle degeneration, enhanced myofibrillar aggregation, and earlier onset of aggregation. These data suggest that strategies aimed at lowering total myotilin levels in LGMD1A patients may be an effective therapeutic approach.
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Affiliation(s)
- Sean M Garvey
- Center for Human Genetics, Duke University Medical Center, P. O. Box 3445, Durham, North Carolina 27710, USA
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Miller BM, Trybus KM. Functional effects of nemaline myopathy mutations on human skeletal alpha-actin. J Biol Chem 2008; 283:19379-88. [PMID: 18477565 DOI: 10.1074/jbc.m801963200] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mutations in human alpha-skeletal actin have been implicated in causing congenital nemaline myopathy, a disease characterized histopathologically by nemaline bodies in skeletal muscle and manifested in the patient as skeletal muscle weakness. Here we investigate the functional effects of three severe nemaline myopathy mutations (V43F, A138P, and R183G) in human alpha-skeletal actin. Wild-type and mutant actins were expressed and purified from the baculovirus/insect cell expression system. The mutations are located in different subdomains of actin; Val-43 is located in a flexible loop of subdomain 2, Ala-138 is near a hydrophobic cleft in the "hinge" region between subdomains 1 and 3, and Arg-183 is near the nucleotide-binding site. None of the three mutations affected the folding of the actin monomer, the velocity at which skeletal myosin moves actin in an in vitro motility assay, or the relative average isometric force supported by F-actin. Defects in fundamental actomyosin interactions are, therefore, unlikely to account for the muscle weakness observed in affected patients. There were, however, significant changes observed in the polymerization kinetics of V43F and A138P and in the rate of nucleotide release for V43F. No detectable defect was found for R183G. If these subtle changes in polymerization observed in vitro are amplified in the context of the sarcomere, it could in principle be one of the primary insults that triggers the development of nemaline myopathy.
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Affiliation(s)
- Becky M Miller
- Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, Vermont 05405, USA
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Tropomyosins in skeletal muscle diseases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2008; 644:143-57. [PMID: 19209820 DOI: 10.1007/978-0-387-85766-4_12] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
A number of congenital muscle diseases and disorders are caused by mutations in genes that encode the proteins present in or associated with the thin filaments of the muscle sarcomere. These genes include alpha-skeletal actin (ACTA1), beta-tropomyosin (TPM2), alpha-tropomyosin slow (TPM3), nebulin (NEB), troponin I fast (TNNI2), troponin T slow (TNNT1), troponin T fast (TNNT3) and cofilin (CFL2). Mutations in two of the four tropomyosin (Tm) genes, TPM2 and TPM3, result in at least three different skeletal muscle diseases and one disorder as distinguished by the presence of specific clinical features and/or structural abnormalities--nemaline myopathy (TPM2 and TPM3), distal arthrogryposis (TPM2), cap disease (TPM2) and congenital fiber type disproportion (TPM3). These diseases have overlapping clinical features and pathologies and there are cases of family members who have the same mutation, but different diseases (Table 1). The relatively recent discovery of nonmuscle or cytoskeletal Tms in skeletal muscle adds to this complexity since it is now possible that a disease-causing mutation could be in a striated isoform and a cytoskeletal isoform both present in muscle.
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Abstract
PURPOSE OF REVIEW The aim of this review is to provide an up-to-date personal analysis of current congenital myopathy research. RECENT FINDINGS In the past year novel congenital myopathies have been suggested, genes have been discovered for some of the congenital myopathies for the first time (beta-tropomyosin in cap disease and perhaps skeletal muscle alpha-actin in Zebra body myopathy), further genes have been identified for congenital myopathies where other genes had already been found (cofilin in nemaline myopathy, selenoprotein N in congenital fibre type disproportion) and recessive myosin storage myopathy was associated with homozygous mutation of slow-skeletal/beta-cardiac myosin which was already known to be mutated in dominant myosin storage myopathy. There has been further clarification of the pathobiology of the congenital myopathies, including determination of the basis of epigenetic effects: silencing of the normal allele in recessive central core disease and persistence of cardiac (fetal) alpha-actin in nemaline myopathy patients with no skeletal actin. SUMMARY The increased understanding of the genes and pathobiology of the congenital myopathies that is developing should ultimately lead to effective treatments.
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Affiliation(s)
- Nigel G Laing
- Centre for Medical Research, University of Western Australia and Western Australian Institute for Medical Research, Nedlands, Western Australia, Australia.
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Bibliography. Current world literature. Neuro-muscular diseases: nerve. Curr Opin Neurol 2007; 20:600-4. [PMID: 17885452 DOI: 10.1097/wco.0b013e3282efeb3b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Vlahovich N, Schevzov G, Nair-Shaliker V, Ilkovski B, Artap ST, Joya JE, Kee AJ, North KN, Gunning PW, Hardeman EC. Tropomyosin 4 defines novel filaments in skeletal muscle associated with muscle remodelling/regeneration in normal and diseased muscle. ACTA ACUST UNITED AC 2007; 65:73-85. [PMID: 17968984 DOI: 10.1002/cm.20245] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Nicole Vlahovich
- Muscle Development Unit, Children's Medical Research Institute, Locked Bag 23, Wentworthville, New South Wales 2145, Australia
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van Lunteren E, Leahy P. Gene expression microarrays and respiratory muscles. Respir Physiol Neurobiol 2006; 156:103-15. [PMID: 17185048 DOI: 10.1016/j.resp.2006.11.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2006] [Revised: 11/09/2006] [Accepted: 11/13/2006] [Indexed: 01/12/2023]
Abstract
The routine measurement of the expression of tens of thousands of gene transcripts, simultaneously, is a defining advance of the last decade which has been made possible by microarray technology. Using this very powerful approach, a pattern has emerged from a number of studies that suggest a molecular niche for the diaphragm which is quite different from that occupied by limb muscle. All indications are that this is true not only in regard to differential gene transcription patterns in healthy muscles but also in the changes in transcription occurring in association with different diseases. Furthermore, respiratory muscle mounts a rich gene expression response to a number of disturbances, be they primary genetic defects (e.g. various types of muscular dystrophies) or non-genetic perturbations (e.g. controlled mechanical ventilation). Large numbers of genes undergo altered levels of transcription, ranging from tens to hundreds (typical) to thousands. These genes are involved in diverse cellular processes, such as contraction, intermediate metabolism, oxidative stress, apoptosis and cellular adhesion. Functional groups of genes identified as having changed expression differ in many respects from one disease to another. Previously identified pathways of muscle injury and repair are often perturbed to greater extents than previously anticipated, and processes not previously suspected of having important roles in the pathophysiology of specific disorders have been identified. Elucidation of these under-appreciated molecular events may lead to novel therapeutic interventions based on disrupting the downstream adverse consequences of the primary event or facilitating events which ameliorate the injury and/or promote muscle healing.
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Affiliation(s)
- Erik van Lunteren
- Division of Pulmonary, Critical Care and Sleep Medicine, Cleveland VA Medical Center and Case Western Reserve University, Cleveland, OH 44106, United States.
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