1
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Lloyd EM, Pinniger GJ, Murphy RM, Grounds MD. Slow or fast: Implications of myofibre type and associated differences for manifestation of neuromuscular disorders. Acta Physiol (Oxf) 2023; 238:e14012. [PMID: 37306196 DOI: 10.1111/apha.14012] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 05/30/2023] [Accepted: 06/06/2023] [Indexed: 06/13/2023]
Abstract
Many neuromuscular disorders can have a differential impact on a specific myofibre type, forming the central premise of this review. The many different skeletal muscles in mammals contain a spectrum of slow- to fast-twitch myofibres with varying levels of protein isoforms that determine their distinctive contractile, metabolic, and other properties. The variations in functional properties across the range of classic 'slow' to 'fast' myofibres are outlined, combined with exemplars of the predominantly slow-twitch soleus and fast-twitch extensor digitorum longus muscles, species comparisons, and techniques used to study these properties. Other intrinsic and extrinsic differences are discussed in the context of slow and fast myofibres. These include inherent susceptibility to damage, myonecrosis, and regeneration, plus extrinsic nerves, extracellular matrix, and vasculature, examined in the context of growth, ageing, metabolic syndrome, and sexual dimorphism. These many differences emphasise the importance of carefully considering the influence of myofibre-type composition on manifestation of various neuromuscular disorders across the lifespan for both sexes. Equally, understanding the different responses of slow and fast myofibres due to intrinsic and extrinsic factors can provide deep insight into the precise molecular mechanisms that initiate and exacerbate various neuromuscular disorders. This focus on the influence of different myofibre types is of fundamental importance to enhance translation for clinical management and therapies for many skeletal muscle disorders.
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Affiliation(s)
- Erin M Lloyd
- Department of Anatomy, Physiology and Human Biology, School of Human Sciences, The University of Western Australia, Perth, Western Australia, Australia
- Curtin Health Innovation Research Institute, Curtin Medical School, Curtin University, Bentley, Western Australia, Australia
| | - Gavin J Pinniger
- Department of Anatomy, Physiology and Human Biology, School of Human Sciences, The University of Western Australia, Perth, Western Australia, Australia
| | - Robyn M Murphy
- Department of Biochemistry and Chemistry, School of Agriculture, Biomedicine and Environment, La Trobe University, Melbourne, Victoria, Australia
| | - Miranda D Grounds
- Department of Anatomy, Physiology and Human Biology, School of Human Sciences, The University of Western Australia, Perth, Western Australia, Australia
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2
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Henning F, Kohn TA. Preservation of shortening velocity and power output in single muscle fibres from patients with idiopathic inflammatory myopathies. J Muscle Res Cell Motil 2022; 44:1-10. [PMID: 36517707 DOI: 10.1007/s10974-022-09638-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2022] [Accepted: 12/05/2022] [Indexed: 12/23/2022]
Abstract
Idiopathic inflammatory myopathies (IIMs) are autoimmune disorders of skeletal muscle causing weakness and disability. Utilizing single fibre contractility studies, we have previously shown that contractility is affected in muscle fibres from individuals with IIMs. For the current study, we hypothesized that a compensatory increase in shortening velocity occurs in muscle fibres from individuals with IIMs in an effort to maintain power output. We performed in vitro single fibre contractility studies to assess force-velocity relationships and maximum shortening velocity (Vmax) of muscle fibres from individuals with IIMs (25 type I and 58 type IIA) and healthy controls (66 type I and 27 type IIA) and calculated maximum power output (Wmax) for each fibre. We found significantly higher Vmax (mean ± SEM) of fibres from individuals with IIMs, for both type I (1.40 ± 0.31 fibre lengths/s, n = vs. 0.63 ± 0.13 fibre lengths/s; p = 0.0019) and type IIA fibres (2.00 ± 0.17 fibre lengths/s vs 0.77 ± 0.10 fibre lengths/s; p < 0.0001). Furthermore, Wmax (mean ± SEM) was maintained compared to fibres from healthy controls, again for both type I and type IIA fibres (4.10 ± 1.00 kN/m2·fibre lengths/s vs. 2.00 ± 0.16 kN/m2·fibre lengths/s; p = ns and 9.00 ± 0.64 kN/m2·fibre lengths/s vs. 6.00 ± 0.67 kN/m2·fibre lengths/s; p = ns respectively). In addition, type I muscle fibres from individuals with IIMs was able to develop maximum power output at lower relative force. The findings of this study suggest that compensatory responses to maintain power output, including increased maximum shortening velocity and improved efficiency, may occur in muscle of individuals with IIMs. The mechanism underlying this response is unclear, and different hypotheses are discussed.
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Affiliation(s)
- Franclo Henning
- Division of Neurology, Department of Medicine, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa.
- Department of Human Biology, University of Cape Town, Anzio Road, Observatory, Cape Town, South Africa.
| | - Tertius Abraham Kohn
- Department of Human Biology, University of Cape Town, Anzio Road, Observatory, Cape Town, South Africa
- Department of Medical Bioscience, Faculty of Natural Sciences, University of the Western Cape, Cape Town, South Africa
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3
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Eraslan G, Drokhlyansky E, Anand S, Fiskin E, Subramanian A, Slyper M, Wang J, Van Wittenberghe N, Rouhana JM, Waldman J, Ashenberg O, Lek M, Dionne D, Win TS, Cuoco MS, Kuksenko O, Tsankov AM, Branton PA, Marshall JL, Greka A, Getz G, Segrè AV, Aguet F, Rozenblatt-Rosen O, Ardlie KG, Regev A. Single-nucleus cross-tissue molecular reference maps toward understanding disease gene function. Science 2022; 376:eabl4290. [PMID: 35549429 PMCID: PMC9383269 DOI: 10.1126/science.abl4290] [Citation(s) in RCA: 127] [Impact Index Per Article: 63.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Understanding gene function and regulation in homeostasis and disease requires knowledge of the cellular and tissue contexts in which genes are expressed. Here, we applied four single-nucleus RNA sequencing methods to eight diverse, archived, frozen tissue types from 16 donors and 25 samples, generating a cross-tissue atlas of 209,126 nuclei profiles, which we integrated across tissues, donors, and laboratory methods with a conditional variational autoencoder. Using the resulting cross-tissue atlas, we highlight shared and tissue-specific features of tissue-resident cell populations; identify cell types that might contribute to neuromuscular, metabolic, and immune components of monogenic diseases and the biological processes involved in their pathology; and determine cell types and gene modules that might underlie disease mechanisms for complex traits analyzed by genome-wide association studies.
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Affiliation(s)
- Gökcen Eraslan
- Klarman Cell Observatory, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Eugene Drokhlyansky
- Klarman Cell Observatory, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Shankara Anand
- The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Evgenij Fiskin
- Klarman Cell Observatory, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Ayshwarya Subramanian
- Klarman Cell Observatory, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Michal Slyper
- Klarman Cell Observatory, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Jiali Wang
- Department of Ophthalmology, Harvard Medical School, Boston, MA 02115, USA
- Ocular Genomics Institute, Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA 02114, USA
- Medical and Population Genetics Program, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | | | - John M. Rouhana
- Department of Ophthalmology, Harvard Medical School, Boston, MA 02115, USA
- Ocular Genomics Institute, Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA 02114, USA
- Medical and Population Genetics Program, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Julia Waldman
- Klarman Cell Observatory, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Orr Ashenberg
- Klarman Cell Observatory, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Monkol Lek
- Department of Genetics, Yale School of Medicine, New Haven, CT 06510, USA
| | - Danielle Dionne
- Klarman Cell Observatory, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Thet Su Win
- Department of Dermatology, Brigham and Women’s Hospital, Boston, MA 02115, USA
| | - Michael S. Cuoco
- Klarman Cell Observatory, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Olena Kuksenko
- Klarman Cell Observatory, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | | | - Philip A. Branton
- The Joint Pathology Center Gynecologic/Breast Pathology, Silver Spring, MD 20910, USA
| | | | - Anna Greka
- The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- Department of Medicine, Brigham and Women’s Hospital, Boston, MA 02115, USA
| | - Gad Getz
- The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- Center for Cancer Research and Department of Pathology, Massachusetts General Hospital, Boston, MA 02114, USA
- Harvard Medical School, Boston, MA 02115, USA
| | - Ayellet V. Segrè
- Department of Ophthalmology, Harvard Medical School, Boston, MA 02115, USA
- Ocular Genomics Institute, Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA 02114, USA
- Medical and Population Genetics Program, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - François Aguet
- The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Orit Rozenblatt-Rosen
- Klarman Cell Observatory, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | | | - Aviv Regev
- Klarman Cell Observatory, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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4
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Kalakoutis M, Di Giulio I, Douiri A, Ochala J, Harridge SDR, Woledge RC. Methodological considerations in measuring specific force in human single skinned muscle fibres. Acta Physiol (Oxf) 2021; 233:e13719. [PMID: 34286921 DOI: 10.1111/apha.13719] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 07/14/2021] [Accepted: 07/15/2021] [Indexed: 02/02/2023]
Abstract
Chemically skinned fibres allow the study of human muscle contractile function in vitro. A particularly important parameter is specific force (SF), that is, maximal isometric force divided by cross-sectional area, representing contractile quality. Although SF varies substantially between studies, the magnitude and cause of this variability remains puzzling. Here, we aimed to summarize and explore the cause of variability in SF between studies. A systematic search was conducted in Medline, Embase and Web of Science databases in June 2020, yielding 137 data sets from 61 publications which studied healthy, young adults. Five-fold differences in mean SF data were observed. Adjustments to the reported data for key methodological differences allowed between-study comparisons to be made. However, adjustment for fibre shape, swelling and sarcomere length failed to significantly reduce SF variance (I2 = 96%). Interestingly, grouping papers based on shared authorship did reveal consistency within research groups. In addition, lower SF was found to be associated with higher phosphocreatine concentrations in the fibre activating solution and with Triton X-100 being used as a skinning agent. Although the analysis showed variance across the literature, the ratio of SF in single fibres containing myosin heavy chain isoforms IIA or I was found to be consistent across research groups. In conclusion, whilst the skinned fibre technique is reliable for studying in vitro force generation of single fibres, the composition of the solution used to activate fibres, which differs between research groups, is likely to heavily influence SF values.
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Affiliation(s)
- Michaeljohn Kalakoutis
- Centre for Human and Applied Physiological Sciences Faculty of Life Sciences & Medicine King’s College London London UK
| | - Irene Di Giulio
- Centre for Human and Applied Physiological Sciences Faculty of Life Sciences & Medicine King’s College London London UK
| | - Abdel Douiri
- School of Population Health and Environmental Sciences King’s College London London UK
| | - Julien Ochala
- Centre for Human and Applied Physiological Sciences Faculty of Life Sciences & Medicine King’s College London London UK
- Department of Biomedical Sciences Faculty of Health and Medical Sciences University of Copenhagen Copenhagen Denmark
| | - Stephen D. R. Harridge
- Centre for Human and Applied Physiological Sciences Faculty of Life Sciences & Medicine King’s College London London UK
| | - Roger C. Woledge
- Centre for Human and Applied Physiological Sciences Faculty of Life Sciences & Medicine King’s College London London UK
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Steenkjaer CH, Mencagli RA, Vaeggemose M, Andersen H. Isokinetic strength and degeneration of lower extremity muscles in patients with myotonic dystrophy; an MRI study. Neuromuscul Disord 2021; 31:198-211. [PMID: 33568272 DOI: 10.1016/j.nmd.2020.12.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Revised: 12/21/2020] [Accepted: 12/22/2020] [Indexed: 01/10/2023]
Abstract
Our aim was to determine isokinetic strength and degeneration of lower extremity muscles in patients with Myotonic Dystrophy (DM1). In 19 patients with DM1 and 19 matched controls, strength measured by isokinetic dynamometry was expressed as percentage of expected strength (ePct), adjusted for age, height, weight and gender. MRI of the hip, thigh and calf muscles were obtained. Fat fraction (FF), mean contractile cross-sectional area (cCSA) and specific strength (Nm/cm2) were calculated. Patients' ankle plantar flexors, knee flexors and extensors had higher FF (Δ: 0.08 - 0.42) and lower cCSA (Δ: 3.2 -17.1 cm2) compared to controls (p ≤ 0.005). EPct (Δ: 19.5 - 41.6%) and specific strength (Δ: 0.27 - 0.96 Nm/cm2) were lower in the majority of patients muscle groups (p˂0.05). Close correlations were found for patients when relating ePct to; FF for plantar flexors (R2=0.742, p<0.001) and knee extensors (R2=0.732, p<0.001), cCSA for plantar flexors (R2=0.696, p<0.001) and knee extensors (R2=0.633, p<0.001), and specific strength for dorsal flexors (ρ=0.855, p = 0.008). In conclusion, patients had weaker lower extremity muscles with higher FF, lower cCSA and specific strength compared to controls. Muscle degeneration determined by quantitative MRI strongly correlated to strength supporting its feasibility to quantify muscle dysfunction in DM1.
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Affiliation(s)
- C H Steenkjaer
- Department of Neurology, Aarhus University Hospital, Aarhus, Denmark.
| | - R A Mencagli
- Department of Neurology, Aarhus University Hospital, Aarhus, Denmark
| | - M Vaeggemose
- Department of Neurology, Aarhus University Hospital, Aarhus, Denmark
| | - H Andersen
- Department of Neurology, Aarhus University Hospital, Aarhus, Denmark
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6
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Henning F, Kohn TA. An exploratory study of contractile force production in muscle fibers from patients with inflammatory myopathies. Muscle Nerve 2020; 62:284-288. [PMID: 32367547 DOI: 10.1002/mus.26904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 03/15/2020] [Accepted: 04/22/2020] [Indexed: 11/06/2022]
Abstract
INTRODUCTION The mechanism by which weakness develops in idiopathic inflammatory myopathies (IIMs) is still unclear. In this study we investigated the maximum force of single muscle fibers from patients with IIMs. METHODS Permeabilized single muscle fibers from patients with IIMs and healthy controls were subjected to contractility measurements. Maximum force and specific force production (maximum force normalized to fiber size) and fiber type were determined for each isolated fiber. RESULTS A total of 178 fibers were studied from five patients with IIMs and 95 fibers from four controls. Specific force production was significantly lower in the IIM group for all fiber types. DISCUSSION The findings from this exploratory study suggest that weakness in IIMs may, in part, be caused by dysfunction of the contractile apparatus. These findings provide a basis for further studies into the mechanisms underlying weakness in IIMs.
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Affiliation(s)
- Franclo Henning
- Division of Neurology, Department of Medicine, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town,, South Africa.,Division of Exercise Science and Sports Medicine, Department of Human Biology, University of Cape Town, Newlands, South Africa
| | - Tertius Abraham Kohn
- Division of Exercise Science and Sports Medicine, Department of Human Biology, University of Cape Town, Newlands, South Africa.,Department of Medical Bioscience, Faculty of Natural Sciences, University of the Western Cape, Cape Town, South Africa
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7
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Lassche S, Voermans NC, van der Pijl R, van den Berg M, Heerschap A, van Hees H, Kusters B, van der Maarel SM, Ottenheijm CAC, van Engelen BGM. Preserved single muscle fiber specific force in facioscapulohumeral muscular dystrophy. Neurology 2020; 94:e1157-e1170. [PMID: 31964688 DOI: 10.1212/wnl.0000000000008977] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2019] [Accepted: 09/20/2019] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To investigate single muscle fiber contractile performance in muscle biopsies from patients with facioscapulohumeral muscular dystrophy (FSHD), one of the most common hereditary muscle disorders. METHODS We collected 50 muscle biopsies (26 vastus lateralis, 24 tibialis anterior) from 14 patients with genetically confirmed FSHD and 12 healthy controls. Single muscle fibers (n = 547) were isolated for contractile measurements. Titin content and titin phosphorylation were examined in vastus lateralis muscle biopsies. RESULTS Single muscle fiber specific force was intact at saturating and physiologic calcium concentrations in all FSHD biopsies, with (FSHDFAT) and without (FSHDNORMAL) fatty infiltration, compared to healthy controls. Myofilament calcium sensitivity of force is increased in single muscle fibers obtained from FSHD muscle biopsies with increased fatty infiltration, but not in FSHD muscle biopsies without fatty infiltration (pCa50: 5.77-5.80 in healthy controls, 5.74-5.83 in FSHDNORMAL, and 5.86-5.90 in FSHDFAT single muscle fibers). Cross-bridge cycling kinetics at saturating calcium concentrations and myofilament cooperativity did not differ from healthy controls. Development of single muscle fiber passive tension was changed in all FSHD vastus lateralis and in FSHDFAT tibialis anterior, resulting in increased fiber stiffness. Titin content was increased in FSHD vastus lateralis biopsies; however, titin phosphorylation did not differ from healthy controls. CONCLUSION Muscle weakness in patients with FSHD is not caused by reduced specific force of individual muscle fibers, even in severely affected tissue with marked fatty infiltration of muscle tissue.
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Affiliation(s)
- Saskia Lassche
- From the Department of Neurology, Donders Institute for Brain, Cognition and Behaviour (S.L., N.C.V., B.G.M.v.E.), Department of Radiology (A.H.), and Department of Pulmonary Diseases (H.V.H.), Radboud University Medical Center, Nijmegen; Department of Physiology (S.L., R.v.d.P., M.v.d.B., C.A.C.O.) and Department of Pathology, Institute for Cardiovascular Research (B.K.), Amsterdam University Medical Center, the Netherlands; Department of Cellular and Molecular Medicine (R.v.d.P., C.A.C.O.), University of Arizona, Tucson; and Department of Human Genetics (S.M.v.d.M.), Leiden University Medical Centre, the Netherlands.
| | - Nicol C Voermans
- From the Department of Neurology, Donders Institute for Brain, Cognition and Behaviour (S.L., N.C.V., B.G.M.v.E.), Department of Radiology (A.H.), and Department of Pulmonary Diseases (H.V.H.), Radboud University Medical Center, Nijmegen; Department of Physiology (S.L., R.v.d.P., M.v.d.B., C.A.C.O.) and Department of Pathology, Institute for Cardiovascular Research (B.K.), Amsterdam University Medical Center, the Netherlands; Department of Cellular and Molecular Medicine (R.v.d.P., C.A.C.O.), University of Arizona, Tucson; and Department of Human Genetics (S.M.v.d.M.), Leiden University Medical Centre, the Netherlands
| | - Robbert van der Pijl
- From the Department of Neurology, Donders Institute for Brain, Cognition and Behaviour (S.L., N.C.V., B.G.M.v.E.), Department of Radiology (A.H.), and Department of Pulmonary Diseases (H.V.H.), Radboud University Medical Center, Nijmegen; Department of Physiology (S.L., R.v.d.P., M.v.d.B., C.A.C.O.) and Department of Pathology, Institute for Cardiovascular Research (B.K.), Amsterdam University Medical Center, the Netherlands; Department of Cellular and Molecular Medicine (R.v.d.P., C.A.C.O.), University of Arizona, Tucson; and Department of Human Genetics (S.M.v.d.M.), Leiden University Medical Centre, the Netherlands
| | - Marloes van den Berg
- From the Department of Neurology, Donders Institute for Brain, Cognition and Behaviour (S.L., N.C.V., B.G.M.v.E.), Department of Radiology (A.H.), and Department of Pulmonary Diseases (H.V.H.), Radboud University Medical Center, Nijmegen; Department of Physiology (S.L., R.v.d.P., M.v.d.B., C.A.C.O.) and Department of Pathology, Institute for Cardiovascular Research (B.K.), Amsterdam University Medical Center, the Netherlands; Department of Cellular and Molecular Medicine (R.v.d.P., C.A.C.O.), University of Arizona, Tucson; and Department of Human Genetics (S.M.v.d.M.), Leiden University Medical Centre, the Netherlands
| | - Arend Heerschap
- From the Department of Neurology, Donders Institute for Brain, Cognition and Behaviour (S.L., N.C.V., B.G.M.v.E.), Department of Radiology (A.H.), and Department of Pulmonary Diseases (H.V.H.), Radboud University Medical Center, Nijmegen; Department of Physiology (S.L., R.v.d.P., M.v.d.B., C.A.C.O.) and Department of Pathology, Institute for Cardiovascular Research (B.K.), Amsterdam University Medical Center, the Netherlands; Department of Cellular and Molecular Medicine (R.v.d.P., C.A.C.O.), University of Arizona, Tucson; and Department of Human Genetics (S.M.v.d.M.), Leiden University Medical Centre, the Netherlands
| | - Hieronymus van Hees
- From the Department of Neurology, Donders Institute for Brain, Cognition and Behaviour (S.L., N.C.V., B.G.M.v.E.), Department of Radiology (A.H.), and Department of Pulmonary Diseases (H.V.H.), Radboud University Medical Center, Nijmegen; Department of Physiology (S.L., R.v.d.P., M.v.d.B., C.A.C.O.) and Department of Pathology, Institute for Cardiovascular Research (B.K.), Amsterdam University Medical Center, the Netherlands; Department of Cellular and Molecular Medicine (R.v.d.P., C.A.C.O.), University of Arizona, Tucson; and Department of Human Genetics (S.M.v.d.M.), Leiden University Medical Centre, the Netherlands
| | - Benno Kusters
- From the Department of Neurology, Donders Institute for Brain, Cognition and Behaviour (S.L., N.C.V., B.G.M.v.E.), Department of Radiology (A.H.), and Department of Pulmonary Diseases (H.V.H.), Radboud University Medical Center, Nijmegen; Department of Physiology (S.L., R.v.d.P., M.v.d.B., C.A.C.O.) and Department of Pathology, Institute for Cardiovascular Research (B.K.), Amsterdam University Medical Center, the Netherlands; Department of Cellular and Molecular Medicine (R.v.d.P., C.A.C.O.), University of Arizona, Tucson; and Department of Human Genetics (S.M.v.d.M.), Leiden University Medical Centre, the Netherlands
| | - Silvère M van der Maarel
- From the Department of Neurology, Donders Institute for Brain, Cognition and Behaviour (S.L., N.C.V., B.G.M.v.E.), Department of Radiology (A.H.), and Department of Pulmonary Diseases (H.V.H.), Radboud University Medical Center, Nijmegen; Department of Physiology (S.L., R.v.d.P., M.v.d.B., C.A.C.O.) and Department of Pathology, Institute for Cardiovascular Research (B.K.), Amsterdam University Medical Center, the Netherlands; Department of Cellular and Molecular Medicine (R.v.d.P., C.A.C.O.), University of Arizona, Tucson; and Department of Human Genetics (S.M.v.d.M.), Leiden University Medical Centre, the Netherlands
| | - Coen A C Ottenheijm
- From the Department of Neurology, Donders Institute for Brain, Cognition and Behaviour (S.L., N.C.V., B.G.M.v.E.), Department of Radiology (A.H.), and Department of Pulmonary Diseases (H.V.H.), Radboud University Medical Center, Nijmegen; Department of Physiology (S.L., R.v.d.P., M.v.d.B., C.A.C.O.) and Department of Pathology, Institute for Cardiovascular Research (B.K.), Amsterdam University Medical Center, the Netherlands; Department of Cellular and Molecular Medicine (R.v.d.P., C.A.C.O.), University of Arizona, Tucson; and Department of Human Genetics (S.M.v.d.M.), Leiden University Medical Centre, the Netherlands
| | - Baziel G M van Engelen
- From the Department of Neurology, Donders Institute for Brain, Cognition and Behaviour (S.L., N.C.V., B.G.M.v.E.), Department of Radiology (A.H.), and Department of Pulmonary Diseases (H.V.H.), Radboud University Medical Center, Nijmegen; Department of Physiology (S.L., R.v.d.P., M.v.d.B., C.A.C.O.) and Department of Pathology, Institute for Cardiovascular Research (B.K.), Amsterdam University Medical Center, the Netherlands; Department of Cellular and Molecular Medicine (R.v.d.P., C.A.C.O.), University of Arizona, Tucson; and Department of Human Genetics (S.M.v.d.M.), Leiden University Medical Centre, the Netherlands
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8
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Lassche S, Rietveld A, Heerschap A, van Hees HW, Hopman MT, Voermans NC, Saris CG, van Engelen BG, Ottenheijm CA. Muscle fiber dysfunction contributes to weakness in inclusion body myositis. Neuromuscul Disord 2019; 29:468-476. [PMID: 31101463 DOI: 10.1016/j.nmd.2019.03.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 01/29/2019] [Accepted: 03/01/2019] [Indexed: 01/12/2023]
Abstract
Atrophy and fatty infiltration are important causes of muscle weakness in inclusion body myositis (IBM). Muscle weakness can also be caused by reduced specific force; i.e. the amount of force generated per unit of residual muscle tissue. This study investigates in vivo specific force of the quadriceps and ex vivo specific force of single muscle fibers in patients with IBM. We included 8 participants with IBM and 12 healthy controls, who all underwent quantitative muscle testing, quantitative MRI of the quadriceps and paired muscle biopsies of the quadriceps and tibialis anterior. Single muscle fibers were isolated to measure muscle fiber specific force and contractile properties. Both in vivo quadriceps specific force and ex vivo muscle fiber specific force were reduced. Muscle fiber dysfunction was accompanied by reduced active stiffness, which reflects a decrease in the number of attached actin-myosin cross-bridges during activation. Myosin concentration was reduced in IBM fibers. Because reduced specific force contributes to muscle weakness in patients with IBM, therapeutic strategies that augment muscle fiber strength may provide benefit to patients with IBM.
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Affiliation(s)
- Saskia Lassche
- Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, PO Box 9101, 6500 HB Nijmegen, The Netherlands; Department of Physiology, Institute for Cardiovascular Research, VU University Medical Center, O/2 Building 11W53, 1081 HZ Amsterdam, The Netherlands.
| | - Anke Rietveld
- Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, PO Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Arend Heerschap
- Department of Radiology, Radboud University Medical Center, PO Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Hieronymus W van Hees
- Department of Pulmonary Diseases, Radboud University Medical Center, PO Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Maria Te Hopman
- Department of Physiology, Radboud University Medical Center, PO Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Nicol C Voermans
- Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, PO Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Christiaan Gj Saris
- Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, PO Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Baziel Gm van Engelen
- Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, PO Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Coen Ac Ottenheijm
- Department of Physiology, Institute for Cardiovascular Research, VU University Medical Center, O/2 Building 11W53, 1081 HZ Amsterdam, The Netherlands
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Talbot J, Maves L. Skeletal muscle fiber type: using insights from muscle developmental biology to dissect targets for susceptibility and resistance to muscle disease. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2016; 5:518-34. [PMID: 27199166 DOI: 10.1002/wdev.230] [Citation(s) in RCA: 210] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Revised: 01/14/2016] [Accepted: 01/16/2016] [Indexed: 12/13/2022]
Abstract
Skeletal muscle fibers are classified into fiber types, in particular, slow twitch versus fast twitch. Muscle fiber types are generally defined by the particular myosin heavy chain isoforms that they express, but many other components contribute to a fiber's physiological characteristics. Skeletal muscle fiber type can have a profound impact on muscle diseases, including certain muscular dystrophies and sarcopenia, the aging-induced loss of muscle mass and strength. These findings suggest that some muscle diseases may be treated by shifting fiber type characteristics either from slow to fast, or fast to slow phenotypes, depending on the disease. Recent studies have begun to address which components of muscle fiber types mediate their susceptibility or resistance to muscle disease. However, for many diseases it remains largely unclear why certain fiber types are affected. A substantial body of work has revealed molecular pathways that regulate muscle fiber type plasticity and early developmental muscle fiber identity. For instance, recent studies have revealed many factors that regulate muscle fiber type through modulating the activity of the muscle regulatory transcription factor MYOD1. Future studies of muscle fiber type development in animal models will continue to enhance our understanding of factors and pathways that may provide therapeutic targets to treat muscle diseases. WIREs Dev Biol 2016, 5:518-534. doi: 10.1002/wdev.230 For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Jared Talbot
- Department of Molecular Genetics, The Ohio State University, Columbus, OH, USA
| | - Lisa Maves
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, WA, USA.,Department of Pediatrics, University of Washington, Seattle, WA, USA
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Magnetic Resonance Assessment of Hypertrophic and Pseudo-Hypertrophic Changes in Lower Leg Muscles of Boys with Duchenne Muscular Dystrophy and Their Relationship to Functional Measurements. PLoS One 2015; 10:e0128915. [PMID: 26103164 PMCID: PMC4477876 DOI: 10.1371/journal.pone.0128915] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Accepted: 05/01/2015] [Indexed: 11/19/2022] Open
Abstract
Introduction The primary objectives of this study were to evaluate contractile and non-contractile content of lower leg muscles of boys with Duchenne muscular dystrophy (DMD) and determine the relationships between non-contractile content and functional abilities. Methods Lower leg muscles of thirty-two boys with DMD and sixteen age matched unaffected controls were imaged. Non-contractile content, contractile cross sectional area and non-contractile cross sectional area of lower leg muscles (tibialis anterior, extensor digitorum longus, peroneal, medial gastrocnemius and soleus) were assessed by magnetic resonance imaging (MRI). Muscle strength, timed functional tests and the Brooke lower extremity score were also assessed. Results Non-contractile content of lower leg muscles (peroneal, medial gastrocnemius, and soleus) was significantly greater than control group (p<0.05). Non-contractile content of lower leg muscles correlated with Brooke score (rs = 0.64-0.84) and 30 feet walk (rs = 0.66-0.80). Dorsiflexor (DF) and plantarflexor (PF) specific torque was significantly different between the groups. Discussion Overall, non-contractile content of the lower leg muscles was greater in DMD than controls. Furthermore, there was an age dependent increase in contractile content in the medial gastrocnemius of boys with DMD. The findings of this study suggest that T1 weighted MR images can be used to monitor disease progression and provide a quantitative estimate of contractile and non-contractile content of tissue in children with DMD.
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Frontera WR, Ochala J. Skeletal muscle: a brief review of structure and function. Calcif Tissue Int 2015; 96:183-95. [PMID: 25294644 DOI: 10.1007/s00223-014-9915-y] [Citation(s) in RCA: 697] [Impact Index Per Article: 77.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Accepted: 09/16/2014] [Indexed: 01/23/2023]
Abstract
Skeletal muscle is one of the most dynamic and plastic tissues of the human body. In humans, skeletal muscle comprises approximately 40% of total body weight and contains 50-75% of all body proteins. In general, muscle mass depends on the balance between protein synthesis and degradation and both processes are sensitive to factors such as nutritional status, hormonal balance, physical activity/exercise, and injury or disease, among others. In this review, we discuss the various domains of muscle structure and function including its cytoskeletal architecture, excitation-contraction coupling, energy metabolism, and force and power generation. We will limit the discussion to human skeletal muscle and emphasize recent scientific literature on single muscle fibers.
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Affiliation(s)
- Walter R Frontera
- Department of Physical Medicine and Rehabilitation, Vanderbilt University School of Medicine, Suite 1318, 2201 Children's Way, Nashville, TN, 37212, USA,
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12
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Abstract
Muscle can be assessed by imaging techniques according to its size (as thickness, area, volume, or alternatively, as a mass) and architecture (fiber length and pennation angle), with values used as an anthropometric measure or a surrogate for force production. Similarly, the size of the bone (as area or volume) can be imaged using MRI or pQCT, although typically bone mineral mass is reported. Bone imaging measures of mineral density, size, and geometry can also be combined to calculate bone's structural strength-measures being highly predictive of bone's failure load ex vivo. Imaging of muscle-bone relationships can, hence, be accomplished through a number of approaches by adoption and comparison of these different muscle and bone parameters, dependent on the research question under investigation. These approaches have revealed evidence of direct, mechanical muscle-bone interactions independent of allometric associations. They have led to important information on bone mechanoadaptation and the influence of muscular action on bone, in addition to influences of age, gender, exercise, and disuse on muscle-bone relationships. Such analyses have also produced promising diagnostic tools for clinical use, such as identification of primary, disuse-induced, and secondary osteoporosis and estimation of bone safety factors. Standardization of muscle-bone imaging methods is required to permit more reliable comparisons between studies and differing imaging modes, and in particular to aid adoption of these methods into widespread clinical practice.
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Affiliation(s)
- Alex Ireland
- Cognitive Motor Function Research Group, Manchester Metropolitan University, Manchester, England
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Lassche S, Stienen GJM, Irving TC, van der Maarel SM, Voermans NC, Padberg GW, Granzier H, van Engelen BGM, Ottenheijm CAC. Sarcomeric dysfunction contributes to muscle weakness in facioscapulohumeral muscular dystrophy. Neurology 2013; 80:733-7. [PMID: 23365058 DOI: 10.1212/wnl.0b013e318282513b] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To investigate whether sarcomeric dysfunction contributes to muscle weakness in facioscapulohumeral muscular dystrophy (FSHD). METHODS Sarcomeric function was evaluated by contractile studies on demembranated single muscle fibers obtained from quadriceps muscle biopsies of 4 patients with FSHD and 4 healthy controls. The sarcomere length dependency of force was determined together with measurements of thin filament length using immunofluorescence confocal scanning laser microscopy. X-ray diffraction techniques were used to study myofilament lattice spacing. RESULTS FSHD muscle fibers produced only 70% of active force compared to healthy controls, a reduction which was exclusive to type II muscle fibers. Changes in force were not due to changes in thin filament length or sarcomere length. Passive force was increased 5- to 12-fold in both fiber types, with increased calcium sensitivity of force generation and decreased myofilament lattice spacing, indicating compensation by the sarcomeric protein titin. CONCLUSIONS We have demonstrated a reduction in sarcomeric force in type II FSHD muscle fibers, and suggest compensatory mechanisms through titin stiffening. Based on these findings, we propose that sarcomeric dysfunction plays a critical role in the development of muscle weakness in FSHD.
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Affiliation(s)
- Saskia Lassche
- Department of Neurology, Neuromuscular Centre Nijmegen, Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands.
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Akima H, Lott D, Senesac C, Deol J, Germain S, Arpan I, Bendixen R, Lee Sweeney H, Walter G, Vandenborne K. Relationships of thigh muscle contractile and non-contractile tissue with function, strength, and age in boys with Duchenne muscular dystrophy. Neuromuscul Disord 2011; 22:16-25. [PMID: 21807516 DOI: 10.1016/j.nmd.2011.06.750] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2011] [Revised: 05/16/2011] [Accepted: 06/27/2011] [Indexed: 10/17/2022]
Abstract
The purpose of this study was to assess the contractile and non-contractile content in thigh muscles of patients with Duchenne muscular dystrophy (DMD) and determine the relationship with functional abilities. Magnetic resonance images of the thigh were acquired in 28 boys with DMD and 10 unaffected boys. Muscle strength, timed functional tests, and the Brookes Lower Extremity scale were also assessed. Non-contractile content in the DMD group was significantly greater than in the control group for six muscles, including rectus femoris, biceps femoris-long head and adductor magnus. Non-contractile content in the total thigh musculature assessed by MRI correlated with the Brookes scale (r(s)=0.75) and supine-up test (r(s)=0.68), as well as other functional measures. An age-related specific torque increase was observed in the control group (r(s)=0.96), but not the DMD (r(s)=0.06). These findings demonstrate that MRI measures of contractile and non-contractile content can provide important information about disease progression in DMD.
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Affiliation(s)
- Hiroshi Akima
- Department of Physical Therapy, University of Florida, Gainesville, FL 32610, USA.
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15
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Krivickas LS, Dorer DJ, Ochala J, Frontera WR. Relationship between force and size in human single muscle fibres. Exp Physiol 2011; 96:539-47. [DOI: 10.1113/expphysiol.2010.055269] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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16
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Abstract
Major advances in the fields of medical science and physiology, molecular genetics, biomedical engineering, and computer science have provided individuals with muscular dystrophy (MD) with more functional equipment, allowing better strategies for improvement of quality of life. These advances have also allowed a significant number of these patients to live much longer. As progress continues to change management, it also changes patients' expectations. A comprehensive medical and rehabilitative approach to management of aging MD patients can often fulfill expectations and help them enjoy an enhanced quality of life.
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Canepari M, Pellegrino MA, D'Antona G, Bottinelli R. Skeletal muscle fibre diversity and the underlying mechanisms. Acta Physiol (Oxf) 2010; 199:465-76. [PMID: 20345415 DOI: 10.1111/j.1748-1716.2010.02118.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The review first briefly summarizes how myosin isoforms have been identified as the major determinant of the functional variability among skeletal muscle fibres. The latter feature is a major characteristic of muscle fibres and a major basis of skeletal muscle heterogeneity and plasticity in vivo. Then, evidence is reported, which indicates that the properties of muscle fibres can vary with no change in the myosin isoform they express. Moreover, the physiological and pathological conditions (ageing, disuse, exercise training, muscular dystrophy) in which such myosin isoform independent change in functional properties occurs and the possible underlying mechanisms are considered. Finally, the known molecular bases of the functional differences among slow and fast isoforms are briefly dealt with.
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Affiliation(s)
- M Canepari
- Department of Physiology and Interuniversity Institute of Myology, University of Pavia, Pavia, Italy
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Vanlinthout LEH, Booij LHDJ, Van Egmond J, Robertson EN. Comparison of mechanomyography and acceleromyography for the assessment of rocuronium induced neuromuscular block in myotonic dystrophy type 1. Anaesthesia 2010; 65:601-607. [DOI: 10.1111/j.1365-2044.2010.06342.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Kimura T, Lueck JD, Harvey PJ, Pace SM, Ikemoto N, Casarotto MG, Dirksen RT, Dulhunty AF. Alternative splicing of RyR1 alters the efficacy of skeletal EC coupling. Cell Calcium 2009; 45:264-74. [PMID: 19131108 DOI: 10.1016/j.ceca.2008.11.005] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2008] [Revised: 11/05/2008] [Accepted: 11/13/2008] [Indexed: 11/16/2022]
Abstract
Alternative splicing of ASI residues (Ala(3481)-Gln(3485)) in the skeletal muscle ryanodine receptor (RyR1) is developmentally regulated: the residues are present in adult ASI(+)RyR1, but absent in the juvenile ASI(-)RyR1 which is over-expressed in adult myotonic dystrophy type 1 (DM1). Although this splicing switch may influence RyR1 function in developing muscle and DM1, little is known about the properties of the splice variants. We examined excitation-contraction (EC) coupling and the structure and interactions of the ASI domain (Thr(3471)-Gly(3500)) in the splice variants. Depolarisation-dependent Ca(2+) release was enhanced by >50% in myotubes expressing ASI(-)RyR1 compared with ASI(+)RyR1, although DHPR L-type currents and SR Ca(2+) content were unaltered, while ASI(-)RyR1 channel function was actually depressed. The effect on EC coupling did not depend on changes in ASI domain secondary structure. Probing RyR1 function with peptides possessing the ASI domain sequence indicated that the domain contributes to an inhibitory module in RyR1. The action of the peptide depended on a sequence of basic residues and their alignment in an alpha-helix adjacent to the ASI splice site. This is the first evidence that the ASI residues contribute to an inhibitory module in RyR1 that influences EC coupling. Implications for development and DM1 are discussed.
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Affiliation(s)
- Takashi Kimura
- Hyogo College of Medicine, 1-1 Mukogawa-cho Nishinomiya, Hyogo 663-8501, Japan
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20
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Krivickas LS, Walsh R, Amato AA. Single muscle fiber contractile properties in adults with muscular dystrophy treated with MYO-029. Muscle Nerve 2009; 39:3-9. [DOI: 10.1002/mus.21200] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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21
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D'Antona G, Brocca L, Pansarasa O, Rinaldi C, Tupler R, Bottinelli R. Structural and functional alterations of muscle fibres in the novel mouse model of facioscapulohumeral muscular dystrophy. J Physiol 2007; 584:997-1009. [PMID: 17855756 PMCID: PMC2277004 DOI: 10.1113/jphysiol.2007.141481] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
We recently generated a mouse model of facioscapulohumeral muscular dystrophy (FSHD) by selectively overexpressing FRG1, a candidate gene for FSHD, in skeletal muscle. The muscles of the FRG-1 mice did not show any plasmamembrane defect suggesting a novel pathogenetic mechanism for FSHD. Here, we study structure and function of muscle fibres from three lines of mice overexpressing FRG1 at different levels: FRG1-low, FRG1-med, FRG1-high. Cross-sectional area (CSA), specific force (Po/CSA) and maximum shortening velocity (V(o)) of identified types of muscle fibres from FRG1-low and FRG1-med mice were analysed and found to be lower than in WT mice. Fast fibres and especially type 2B fibres (the fastest type) were preferentially involved in the dystrophic process showing a much larger force deficit than type 1 (slow) fibres. Consistent with the latter observation, the MHC isoform distribution of several muscles of the three FRG1 lines showed a shift towards slower MHC isoforms in comparison to WT muscle. Moreover, fast muscles showed a more evident histological deterioration, a larger atrophy and a higher percentage of centrally nucleated fibres than the soleus, the slowest muscle in mice. Interestingly, loss in CSA, Po/CSA and V(o) of single muscle fibres and MHC isoform shift towards a slower phenotype can be considered early signs of muscular dystrophy (MD). They were, in fact, found also in FRG1-low mice which did not show any impairment of function in vivo and of muscle size in vitro and in soleus muscles, which had a completely preserved morphology. This study provides a detailed characterization of structure and function of muscle fibres in a novel murine model of one of the main human MDs and suggests that fundamental features of the dystrophic process, common to most MDs, such as the intrinsic loss of contractile strength of muscle fibres, the preferential involvement of fast fibres and the shift towards a slow muscle phenotype can occur independently from obvious alterations of the plasma membrane.
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Affiliation(s)
- Giuseppe D'Antona
- Department of Experimental Medicine, Human Physiology Unit, University of Pavia, Via Forlanini 6, 27100, Pavia, Italy.
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Krivickas LS, Frontera WR. Single Muscle Fiber Physiology in Neuromuscular Disease. Phys Med Rehabil Clin N Am 2005; 16:951-65, ix. [PMID: 16214053 DOI: 10.1016/j.pmr.2005.08.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Lisa S Krivickas
- Harvard Medical School, Spaulding Rehabilitation Hospital, 125 Nashua Street, Boston, MA 02114, USA.
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Krivickas LS, Amato AA, Krishnan G, Murray AV, Frontera WR. Preservation of in vitro muscle fiber function in dermatomyositis and inclusion body myositis: a single fiber study. Neuromuscul Disord 2005; 15:349-54. [PMID: 15833427 DOI: 10.1016/j.nmd.2005.01.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2004] [Revised: 01/05/2005] [Accepted: 01/13/2005] [Indexed: 11/21/2022]
Abstract
Five patients with untreated dermatomyositis, five with inclusion body myositis, and 16 healthy elderly volunteer subjects (controls) underwent open (dermatomyositis and inclusion body myositis) or percutaneous (controls) muscle biopsy. Biopsied muscles included deltoid, biceps and vastus lateralis. Chemically skinned single muscle fibers were activated with Ca(+2); the slack test was performed to determine maximal unloaded shortening velocity (Vo). Parameters measured include single fiber cross sectional area, maximal force, specific force and Vo. 429 Type I and 94 Type IIA fibers were studied. Cross sectional area and maximal force were greater in inclusion body myositis than dermatomyositis or control for Type I and IIA fibers. Specific force of Type I fibers was similar in inclusion body myositis and dermatomyositis but greater than in controls. Vo was greater in Type I, but not IIA, fibers in dermatomyositis compared with inclusion body myositis and controls. The force and velocity generating capacity of single muscle fibers is preserved in patients with dermatomyositis and inclusion body myositis suggesting that dysfunction of the contractile proteins does not contribute to clinical muscle weakness.
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Affiliation(s)
- Lisa S Krivickas
- Department of Physical Medicine and Rehabilitation, Spaulding Rehabilitation Hospital and Harvard Medical School, 125 Nashua St., Boston, MA 02114, USA.
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Carroll CC, Carrithers JA, Trappe TA. Contractile protein concentrations in human single muscle fibers. J Muscle Res Cell Motil 2004; 25:55-9. [PMID: 15160488 DOI: 10.1023/b:jure.0000021362.55389.6b] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The intent of this investigation was twofold: (1) to develop a convenient method for analyzing skeletal muscle protein concentrations in a large number of individual human single fibers and (2) to compare the myosin heavy chain (MHC) and actin concentrations in fibers expressing pure MHC I or MHC IIa. Individual vastus lateralis fibers were dissected from five individuals (3 M, 2 F; 24 +/- 1 years) and used to determine single fiber total protein (TP) concentration and MHC distribution. Fibers expressing pure MHC I and MHC IIa were further analyzed for MHC (252 fibers; mean of 50/subject) and actin (160 fibers; mean of 32/subject) concentration relative to TP. Single fiber MHC concentration was 26 +/- 4% greater (P < 0.05) in MHC IIa (364 +/- 39 micrograms MHC/mg TP) vs. MHC I (266 +/- 29 micrograms MHC/mg TP) fibers. No differences (P > 0.05) were noted in single fiber actin concentration (MHC I: 171 +/- 17 micrograms actin/mg TP; MHC IIa: 165 +/- 17 micrograms actin/mg TP). These data indicate that within the TP fraction, skeletal muscle fibers contain differing amounts of MHC, and this appears to be fiber type specific. These data and methods have implications for the study of human muscle fiber type specific alterations in various protein concentrations in response to exercise, models of unloading, and aging.
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Affiliation(s)
- Chad C Carroll
- Nutrition, Metabolism and Exercise Laboratory, DWR Department of Geriatrics, University of Arkansas for Medical Sciences, Little Rock, AR, USA
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25
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Krivickas LS, Yang JI, Kim SK, Frontera WR. Skeletal muscle fiber function and rate of disease progression in amyotrophic lateral sclerosis. Muscle Nerve 2002; 26:636-43. [PMID: 12402285 DOI: 10.1002/mus.10257] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The contractile properties of single muscle fibers reflect the functional status of muscle at the cellular level and have not been described in amyotrophic lateral sclerosis (ALS). Chemically skinned single muscle fibers (n = 173), obtained by needle biopsy from six men with ALS, were activated with Ca(2+), allowing maximal force measurements and specific force (SF) estimates. Maximum unloaded shortening velocity (V(o)) was determined using the slack test. The results were compared with muscle from healthy controls. Markers of disease progression included rate of change of ALS functional rating scale score, rate of change of forced vital capacity, and disease duration. Compared with controls, ALS patients had decreased whole muscle SF (measured by a combination of computerized tomography and isokinetic testing) but normal single fiber SF. The V(o) was greater for type I fibers in ALS. Patients with slower disease progression had increased single fiber size and a high percentage of hybrid fibers (expressing multiple myosin heavy chain isoforms). A needle biopsy obtained at the time of ALS diagnosis may assist with predicting rate of disease progression.
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Affiliation(s)
- Lisa S Krivickas
- Department of Physical Medicine and Rehabilitation, Spaulding Rehabilitation Hospital and Harvard Medical School, 125 Nashua St., Boston, Massachusetts 02114, USA.
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Reddy S, Mistry DJ, Wang QC, Geddis LM, Kutchai HC, Moorman JR, Mounsey JP. Effects of age and gene dose on skeletal muscle sodium channel gating in mice deficient in myotonic dystrophy protein kinase. Muscle Nerve 2002; 25:850-7. [PMID: 12115974 DOI: 10.1002/mus.10127] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Myotonic muscular dystrophy (DM) is characterized by abnormal skeletal muscle Na channel gating and reduced levels of myotonic dystrophy protein kinase (DMPK). Electrophysiological measurements show that mice deficient in Dmpk have reduced Na currents in muscle. We now find that the Na channel expression level is normal in mouse muscle partially or completely deficient in Dmpk. Reduced current amplitudes are not changed by age or gene dose, and the reduction is not due to changes in macroscopic or microscopic gating kinetics. The mechanism of abnormal membrane excitability in DM may in part be silencing of muscle Na channels due to Dmpk deficiency.
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Affiliation(s)
- Sita Reddy
- Institute for Genetic Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
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