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Dugdale HF, Levy Y, Jungbluth H, Oldfors A, Ochala J. Aberrant myonuclear domains and impaired myofiber contractility despite marked hypertrophy in MYMK-related, Carey-Fineman-Ziter Syndrome. Acta Neuropathol Commun 2024; 12:80. [PMID: 38790073 PMCID: PMC11127446 DOI: 10.1186/s40478-024-01783-2] [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: 02/09/2024] [Accepted: 04/10/2024] [Indexed: 05/26/2024] Open
Abstract
Carey Fineman Ziter Syndrome (CFZS) is a rare autosomal recessive disease caused by mutations in the MYMK locus which encodes the protein, myomaker. Myomaker is essential for fusion and concurrent myonuclei donation of muscle progenitors during growth and development. Strikingly, in humans, MYMK mutations appear to prompt myofiber hypertrophy but paradoxically, induce generalised muscle weakness. As the underlying cellular mechanisms remain unexplored, the present study aimed to gain insights by combining myofiber deep-phenotyping and proteomic profiling. Hence, we isolated individual muscle fibers from CFZS patients and performed mechanical, 3D morphological and proteomic analyses. Myofibers from CFZS patients were ~ 4x larger than controls and possessed ~ 2x more myonuclei than those from healthy subjects, leading to disproportionally larger myonuclear domain volumes. These greater myonuclear domain sizes were accompanied by smaller intrinsic cellular force generating-capacities in myofibers from CFZS patients than in control muscle cells. Our complementary proteomic analyses indicated remodelling in 233 proteins particularly those associated with cellular respiration. Overall, our findings suggest that myomaker is somewhat functional in CFZS patients, but the associated nuclear accretion may ultimately lead to non-functional hypertrophy and altered energy-related mechanisms in CFZS patients. All of these are likely contributors of the muscle weakness experienced by CFZS patients.
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Affiliation(s)
- Hannah F Dugdale
- School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
- Centre for Human and Applied Physiological Sciences, School of Basic and Medical Biosciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Yotam Levy
- Centre for Human and Applied Physiological Sciences, School of Basic and Medical Biosciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Heinz Jungbluth
- Randall Centre for Cell and Molecular Biophysics, Muscle Signalling Section, Faculty of Life Sciences and Medicine (FoLSM), King's College London, London, UK
- Department of Paediatric Neurology, Neuromuscular Service, Evelina Children's Hospital, Guy's and St Thomas' Hospital NHS Foundation Trust, London, UK
| | - Anders Oldfors
- Department of Laboratory Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Julien Ochala
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
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2
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Battey E, Levy Y, Pollock RD, Pugh JN, Close GL, Kalakoutis M, Lazarus NR, Harridge SDR, Ochala J, Stroud MJ. Muscle fibre size and myonuclear positioning in trained and aged humans. Exp Physiol 2024; 109:549-561. [PMID: 38461483 PMCID: PMC10988734 DOI: 10.1113/ep091567] [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: 10/04/2023] [Accepted: 02/05/2024] [Indexed: 03/12/2024]
Abstract
Changes in myonuclear architecture and positioning are associated with exercise adaptations and ageing. However, data on the positioning and number of myonuclei following exercise are inconsistent. Additionally, whether myonuclear domains (MNDs; i.e., the theoretical volume of cytoplasm within which a myonucleus is responsible for transcribing DNA) and myonuclear positioning are altered with age remains unclear. The aim of this investigation was to investigate relationships between age and activity status and myonuclear domains and positioning. Vastus lateralis muscle biopsies from younger endurance-trained (YT) and older endurance-trained (OT) individuals were compared with age-matched untrained counterparts (YU and OU; OU samples were acquired during surgical operation). Serial, optical z-slices were acquired throughout isolated muscle fibres and analysed to give three-dimensional coordinates for myonuclei and muscle fibre dimensions. The mean cross-sectional area (CSA) of muscle fibres from OU individuals was 33%-53% smaller compared with the other groups. The number of nuclei relative to fibre CSA was 90% greater in OU compared with YU muscle fibres. Additionally, scaling of MND volume with fibre size was altered in older untrained individuals. The myonuclear arrangement, in contrast, was similar across groups. Fibre CSA and most myonuclear parameters were significantly associated with age in untrained individuals, but not in trained individuals. These data indicate that regular endurance exercise throughout the lifespan might better preserve the size of muscle fibres in older age and maintain the relationship between fibre size and MND volumes. Inactivity, however, might result in reduced muscle fibre size and altered myonuclear parameters.
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Affiliation(s)
- Edmund Battey
- Centre for Human & Applied Physiological Sciences, Faculty of Life Sciences & MedicineKing's College LondonLondonUK
- British Heart Foundation Centre of Research Excellence, School of Cardiovascular Medicine and SciencesKing's College LondonLondonUK
- Department of Biomedical Sciences, Faculty of Medical and Health SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Yotam Levy
- Centre for Human & Applied Physiological Sciences, Faculty of Life Sciences & MedicineKing's College LondonLondonUK
| | - Ross D. Pollock
- Centre for Human & Applied Physiological Sciences, Faculty of Life Sciences & MedicineKing's College LondonLondonUK
| | - Jamie N. Pugh
- School of Sport and Exercise Sciences, Tom Reilly Building, Byrom StreetLiverpool John Moores UniversityLiverpoolUK
| | - Graeme L. Close
- School of Sport and Exercise Sciences, Tom Reilly Building, Byrom StreetLiverpool John Moores UniversityLiverpoolUK
| | - Michaeljohn Kalakoutis
- Centre for Human & Applied Physiological Sciences, Faculty of Life Sciences & MedicineKing's College LondonLondonUK
- Randall Centre for Cell and Molecular Biophysics, Faculty of Life Sciences & MedicineKing's College LondonLondonUK
| | - Norman R. Lazarus
- Centre for Human & Applied Physiological Sciences, Faculty of Life Sciences & MedicineKing's College LondonLondonUK
| | - Stephen D. R. Harridge
- Centre for Human & Applied Physiological Sciences, Faculty of Life Sciences & MedicineKing's College LondonLondonUK
| | - Julien Ochala
- Centre for Human & Applied Physiological Sciences, Faculty of Life Sciences & MedicineKing's College LondonLondonUK
- Department of Biomedical Sciences, Faculty of Medical and Health SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Matthew J. Stroud
- British Heart Foundation Centre of Research Excellence, School of Cardiovascular Medicine and SciencesKing's College LondonLondonUK
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3
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Cisterna B, Malatesta M. Molecular and Structural Alterations of Skeletal Muscle Tissue Nuclei during Aging. Int J Mol Sci 2024; 25:1833. [PMID: 38339110 PMCID: PMC10855217 DOI: 10.3390/ijms25031833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Revised: 01/30/2024] [Accepted: 01/31/2024] [Indexed: 02/12/2024] Open
Abstract
Aging is accompanied by a progressive loss of skeletal muscle mass and strength. The mechanisms underlying this phenomenon are certainly multifactorial and still remain to be fully elucidated. Changes in the cell nucleus structure and function have been considered among the possible contributing causes. This review offers an overview of the current knowledge on skeletal muscle nuclei in aging, focusing on the impairment of nuclear pathways potentially involved in age-related muscle decline. In skeletal muscle two types of cells are present: fiber cells, constituting the contractile muscle mass and containing hundreds of myonuclei, and the satellite cells, i.e., the myogenic mononuclear stem cells occurring at the periphery of the fibers and responsible for muscle growth and repair. Research conducted on different experimental models and with different methodological approaches demonstrated that both the myonuclei and satellite cell nuclei of aged skeletal muscles undergo several structural and molecular alterations, affecting chromatin organization, gene expression, and transcriptional and post-transcriptional activities. These alterations play a key role in the impairment of muscle fiber homeostasis and regeneration, thus contributing to the age-related decrease in skeletal muscle mass and function.
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Affiliation(s)
| | - Manuela Malatesta
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Strada Le Grazie 8, 37134 Verona, Italy;
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4
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Bagley JR, Denes LT, McCarthy JJ, Wang ET, Murach KA. The myonuclear domain in adult skeletal muscle fibres: past, present and future. J Physiol 2023; 601:723-741. [PMID: 36629254 PMCID: PMC9931674 DOI: 10.1113/jp283658] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 01/06/2023] [Indexed: 01/12/2023] Open
Abstract
Most cells in the body are mononuclear whereas skeletal muscle fibres are uniquely multinuclear. The nuclei of muscle fibres (myonuclei) are usually situated peripherally which complicates the equitable distribution of gene products. Myonuclear abundance can also change under conditions such as hypertrophy and atrophy. Specialised zones in muscle fibres have different functions and thus distinct synthetic demands from myonuclei. The complex structure and regulatory requirements of multinuclear muscle cells understandably led to the hypothesis that myonuclei govern defined 'domains' to maintain homeostasis and facilitate adaptation. The purpose of this review is to provide historical context for the myonuclear domain and evaluate its veracity with respect to mRNA and protein distribution resulting from myonuclear transcription. We synthesise insights from past and current in vitro and in vivo genetically modified models for studying the myonuclear domain under dynamic conditions. We also cover the most contemporary knowledge on mRNA and protein transport in muscle cells. Insights from emerging technologies such as single myonuclear RNA-sequencing further inform our discussion of the myonuclear domain. We broadly conclude: (1) the myonuclear domain can be flexible during muscle fibre growth and atrophy, (2) the mechanisms and role of myonuclear loss and motility deserve further consideration, (3) mRNA in muscle is actively transported via microtubules and locally restricted, but proteins may travel far from a myonucleus of origin and (4) myonuclear transcriptional specialisation extends beyond the classic neuromuscular and myotendinous populations. A deeper understanding of the myonuclear domain in muscle may promote effective therapies for ageing and disease.
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Affiliation(s)
- James R. Bagley
- Muscle Physiology Laboratory, Department of Kinesiology, San Francisco State University, San Francisco, California
| | | | - John J. McCarthy
- The Center for Muscle Biology, University of Kentucky, Lexington, Kentucky
- Department of Physiology, College of Medicine, University of Kentucky
| | - Eric T. Wang
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics, University of Florida, Gainesville, Florida
- Myology Institute, University of Florida
- Genetics Institute, University of Florida
| | - Kevin A. Murach
- Exercise Science Research Center, Department of Health, Human Performance, and Recreation, University of Arkansas, Fayetteville, Arkansas
- Cell and Molecular Biology Graduate Program, University of Arkansas
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5
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Battey E, Ross JA, Hoang A, Wilson DGS, Han Y, Levy Y, Pollock RD, Kalakoutis M, Pugh JN, Close GL, Ellison-Hughes GM, Lazarus NR, Iskratsch T, Harridge SDR, Ochala J, Stroud MJ. Myonuclear alterations associated with exercise are independent of age in humans. J Physiol 2023. [PMID: 36597809 DOI: 10.1113/jp284128] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 12/19/2022] [Indexed: 01/05/2023] Open
Abstract
Age-related decline in skeletal muscle structure and function can be mitigated by regular exercise. However, the precise mechanisms that govern this are not fully understood. The nucleus plays an active role in translating forces into biochemical signals (mechanotransduction), with the nuclear lamina protein lamin A regulating nuclear shape, nuclear mechanics and ultimately gene expression. Defective lamin A expression causes muscle pathologies and premature ageing syndromes, but the roles of nuclear structure and function in physiological ageing and in exercise adaptations remain obscure. Here, we isolated single muscle fibres and carried out detailed morphological and functional analyses on myonuclei from young and older exercise-trained individuals. Strikingly, myonuclei from trained individuals were more spherical, less deformable, and contained a thicker nuclear lamina than those from untrained individuals. Complementary to this, exercise resulted in increased levels of lamin A and increased myonuclear stiffness in mice. We conclude that exercise is associated with myonuclear remodelling, independently of age, which may contribute to the preservative effects of exercise on muscle function throughout the lifespan. KEY POINTS: The nucleus plays an active role in translating forces into biochemical signals. Myonuclear aberrations in a group of muscular dystrophies called laminopathies suggest that the shape and mechanical properties of myonuclei are important for maintaining muscle function. Here, striking differences are presented in myonuclear shape and mechanics associated with exercise, in both young and old humans. Myonuclei from trained individuals were more spherical, less deformable and contained a thicker nuclear lamina than untrained individuals. It is concluded that exercise is associated with age-independent myonuclear remodelling, which may help to maintain muscle function throughout the lifespan.
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Affiliation(s)
- E Battey
- Centre for Human & Applied Physiological Sciences, Faculty of Life Sciences & Medicine, King's College London, London, UK
- British Heart Foundation Centre of Research Excellence, School of Cardiovascular Medicine and Sciences, King's College London, London, UK
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - J A Ross
- British Heart Foundation Centre of Research Excellence, School of Cardiovascular Medicine and Sciences, King's College London, London, UK
| | - A Hoang
- British Heart Foundation Centre of Research Excellence, School of Cardiovascular Medicine and Sciences, King's College London, London, UK
| | - D G S Wilson
- School of Engineering and Materials Science, Queen Mary University of London, London, UK
| | - Y Han
- Centre for Human & Applied Physiological Sciences, Faculty of Life Sciences & Medicine, King's College London, London, UK
| | - Y Levy
- Centre for Human & Applied Physiological Sciences, Faculty of Life Sciences & Medicine, King's College London, London, UK
| | - R D Pollock
- Centre for Human & Applied Physiological Sciences, Faculty of Life Sciences & Medicine, King's College London, London, UK
| | - M Kalakoutis
- Centre for Human & Applied Physiological Sciences, Faculty of Life Sciences & Medicine, King's College London, London, UK
- Randall Centre for Cell and Molecular Biophysics, Faculty of Life Sciences & Medicine, King's College London, London, UK
| | - J N Pugh
- School of Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK
| | - G L Close
- School of Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK
| | - G M Ellison-Hughes
- Centre for Human & Applied Physiological Sciences, Faculty of Life Sciences & Medicine, King's College London, London, UK
| | - N R Lazarus
- Centre for Human & Applied Physiological Sciences, Faculty of Life Sciences & Medicine, King's College London, London, UK
| | - T Iskratsch
- School of Engineering and Materials Science, Queen Mary University of London, London, UK
- Randall Centre for Cell and Molecular Biophysics, Faculty of Life Sciences & Medicine, King's College London, London, UK
| | - S D R Harridge
- Centre for Human & Applied Physiological Sciences, Faculty of Life Sciences & Medicine, King's College London, London, UK
| | - J Ochala
- Centre for Human & 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
| | - M J Stroud
- British Heart Foundation Centre of Research Excellence, School of Cardiovascular Medicine and Sciences, King's College London, London, UK
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6
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Brayson D, Shanahan CM. Lamin A precursor localizes to the Z-disc of sarcomeres in the heart and is dynamically regulated in muscle cell differentiation. Philos Trans R Soc Lond B Biol Sci 2022; 377:20210490. [PMID: 36189817 DOI: 10.1098/rstb.2021.0490] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The lamin A precursor, prelamin A, requires extensive processing to yield mature lamin A and effect its primary function as a structural filament of the nucleoskeleton. When processing is perturbed, nuclear accumulation of prelamin A is toxic and causes laminopathic diseases such as Hutchinson-Gilford progeria syndrome and cardiomyopathy. However, the physiological role of prelamin A is largely unknown and we sought to identify novel insights about this. Using rodent heart tissue, primary cells and the C2C12 model of myofibrillogenesis, we investigated the expression and localization patterns of prelamin A in heart and skeletal muscle cells. We found that endogenous prelamin A was detectable in mouse heart localized to the sarcomere in both adult mouse heart and isolated neonatal rat cardiomyocytes. We investigated the regulation of prelamin A in C2C12 myofibrillogenesis and found it was dynamically regulated and organized into striations upon myofibril formation, colocalizing with the Z-disc protein α-actinin. These data provide evidence that prelamin A is a component of the sarcomere, underpinning a physiological purpose for unprocessed prelamin A. This article is part of the theme issue 'The cardiomyocyte: new revelations on the interplay between architecture and function in growth, health, and disease'.
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Affiliation(s)
- Daniel Brayson
- Dubowitz Neuromuscular Centre, UCL Great Ormond Street Institute of Child Health, London, UK.,School of Cardiovascular Medicine and Sciences, King's College London BHF Centre for Research Excellence, London, UK
| | - Catherine M Shanahan
- School of Cardiovascular Medicine and Sciences, King's College London BHF Centre for Research Excellence, London, UK
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7
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Xiang Y, You Z, Huang X, Dai J, Zhang J, Nie S, Xu L, Jiang J, Xu J. Oxidative stress-induced premature senescence and aggravated denervated skeletal muscular atrophy by regulating progerin-p53 interaction. Skelet Muscle 2022; 12:19. [PMID: 35906707 PMCID: PMC9335985 DOI: 10.1186/s13395-022-00302-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 07/21/2022] [Indexed: 11/17/2022] Open
Abstract
Background Progerin elevates atrophic gene expression and helps modify the nuclear membrane to cause severe muscle pathology, which is similar to muscle weakness in the elderly, to alter the development and function of the skeletal muscles. Stress-induced premature senescence (SIPS), a state of cell growth arrest owing to such stimuli as oxidation, can be caused by progerin. However, evidence for whether SIPS-induced progerin accumulation is connected to denervation-induced muscle atrophy is not sufficient. Methods Flow cytometry and a reactive oxygen species (ROS) as well as inducible nitric oxide synthase (iNOS) inhibitors were used to assess the effect of oxidation on protein (p53), progerin, and nuclear progerin–p53 interaction in the denervated muscles of models of mice suffering from sciatic injury. Loss-of-function approach with the targeted deletion of p53 was used to assess connection among SIPS, denervated muscle atrophy, and fibrogenesis. Results The augmentation of ROS and iNOS-derived NO in the denervated muscles of models of mice suffering from sciatic injury upregulates p53 and progerin. The abnormal accumulation of progerin in the nuclear membrane as well as the activation of nuclear progerin–p53 interaction triggered premature senescence in the denervated muscle cells of mice. The p53-dependent SIPS in denervated muscles contributes to their atrophy and fibrogenesis. Conclusion Oxidative stress-triggered premature senescence via nuclear progerin–p53 interaction that promotes denervated skeletal muscular atrophy and fibrogenesis. Supplementary Information The online version contains supplementary material available at 10.1186/s13395-022-00302-y.
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Affiliation(s)
- Yaoxian Xiang
- Department of Hand Surgery, Huashan Hospital, Fudan University, Shanghai, People's Republic of China.,NHC Key Laboratory of Hand Reconstruction, (Fudan University), Shanghai, People's Republic of China.,Shanghai Key Laboratory of Peripheral Nerve and Microsurgery, Shanghai, People's Republic of China
| | - Zongqi You
- Department of Hand Surgery, Huashan Hospital, Fudan University, Shanghai, People's Republic of China.,NHC Key Laboratory of Hand Reconstruction, (Fudan University), Shanghai, People's Republic of China.,Shanghai Key Laboratory of Peripheral Nerve and Microsurgery, Shanghai, People's Republic of China
| | - Xinying Huang
- Department of Hand Surgery, Huashan Hospital, Fudan University, Shanghai, People's Republic of China.,NHC Key Laboratory of Hand Reconstruction, (Fudan University), Shanghai, People's Republic of China.,Shanghai Key Laboratory of Peripheral Nerve and Microsurgery, Shanghai, People's Republic of China.,Shanghai Medical College of Fudan University, Shanghai, People's Republic of China
| | - Junxi Dai
- Department of Hand Surgery, Huashan Hospital, Fudan University, Shanghai, People's Republic of China.,NHC Key Laboratory of Hand Reconstruction, (Fudan University), Shanghai, People's Republic of China.,Shanghai Key Laboratory of Peripheral Nerve and Microsurgery, Shanghai, People's Republic of China
| | - Junpeng Zhang
- School of Rehabilitation Science, Shanghai University of Traditional Chinese Medicine, Shanghai, People's Republic of China
| | - Shuqi Nie
- Shanghai Medical College of Fudan University, Shanghai, People's Republic of China
| | - Lei Xu
- Department of Hand Surgery, Huashan Hospital, Fudan University, Shanghai, People's Republic of China.,NHC Key Laboratory of Hand Reconstruction, (Fudan University), Shanghai, People's Republic of China.,Shanghai Key Laboratory of Peripheral Nerve and Microsurgery, Shanghai, People's Republic of China
| | - Junjian Jiang
- Department of Hand Surgery, Huashan Hospital, Fudan University, Shanghai, People's Republic of China. .,NHC Key Laboratory of Hand Reconstruction, (Fudan University), Shanghai, People's Republic of China. .,Shanghai Key Laboratory of Peripheral Nerve and Microsurgery, Shanghai, People's Republic of China.
| | - Jianguang Xu
- Department of Hand Surgery, Huashan Hospital, Fudan University, Shanghai, People's Republic of China. .,NHC Key Laboratory of Hand Reconstruction, (Fudan University), Shanghai, People's Republic of China. .,Shanghai Key Laboratory of Peripheral Nerve and Microsurgery, Shanghai, People's Republic of China. .,School of Rehabilitation Science, Shanghai University of Traditional Chinese Medicine, Shanghai, People's Republic of China.
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8
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Myofibre Hyper-Contractility in Horses Expressing the Myosin Heavy Chain Myopathy Mutation, MYH1E321G. Cells 2021; 10:cells10123428. [PMID: 34943936 PMCID: PMC8699922 DOI: 10.3390/cells10123428] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 11/30/2021] [Accepted: 12/02/2021] [Indexed: 11/17/2022] Open
Abstract
Myosinopathies are defined as a group of muscle disorders characterized by mutations in genes encoding myosin heavy chains. Their exact molecular and cellular mechanisms remain unclear. In the present study, we have focused our attention on a MYH1-related E321G amino acid substitution within the head region of the type IIx skeletal myosin heavy chain, associated with clinical signs of atrophy, inflammation and/or profound rhabdomyolysis, known as equine myosin heavy chain myopathy. We performed Mant-ATP chase experiments together with force measurements on isolated IIx myofibres from control horses (MYH1E321G−/−) and Quarter Horses homozygous (MYH1E321G+/+) or heterozygous (MYH1E321G+/−) for the E321G mutation. The single residue replacement did not affect the relaxed conformations of myosin molecules. Nevertheless, it significantly increased its active behaviour as proven by the higher maximal force production and Ca2+ sensitivity for MYH1E321G+/+ in comparison with MYH1E321G+/− and MYH1E321G−/− horses. Altogether, these findings indicate that, in the presence of the E321G mutation, a molecular and cellular hyper-contractile phenotype occurs which could contribute to the development of the myosin heavy chain myopathy.
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9
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Ghasemizadeh A, Christin E, Guiraud A, Couturier N, Abitbol M, Risson V, Girard E, Jagla C, Soler C, Laddada L, Sanchez C, Jaque-Fernandez FI, Jacquemond V, Thomas JL, Lanfranchi M, Courchet J, Gondin J, Schaeffer L, Gache V. MACF1 controls skeletal muscle function through the microtubule-dependent localization of extra-synaptic myonuclei and mitochondria biogenesis. eLife 2021; 10:e70490. [PMID: 34448452 PMCID: PMC8500715 DOI: 10.7554/elife.70490] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 08/10/2021] [Indexed: 01/02/2023] Open
Abstract
Skeletal muscles are composed of hundreds of multinucleated muscle fibers (myofibers) whose myonuclei are regularly positioned all along the myofiber's periphery except the few ones clustered underneath the neuromuscular junction (NMJ) at the synaptic zone. This precise myonuclei organization is altered in different types of muscle disease, including centronuclear myopathies (CNMs). However, the molecular machinery regulating myonuclei position and organization in mature myofibers remains largely unknown. Conversely, it is also unclear how peripheral myonuclei positioning is lost in the related muscle diseases. Here, we describe the microtubule-associated protein, MACF1, as an essential and evolutionary conserved regulator of myonuclei positioning and maintenance, in cultured mammalian myotubes, in Drosophila muscle, and in adult mammalian muscle using a conditional muscle-specific knockout mouse model. In vitro, we show that MACF1 controls microtubules dynamics and contributes to microtubule stabilization during myofiber's maturation. In addition, we demonstrate that MACF1 regulates the microtubules density specifically around myonuclei, and, as a consequence, governs myonuclei motion. Our in vivo studies show that MACF1 deficiency is associated with alteration of extra-synaptic myonuclei positioning and microtubules network organization, both preceding NMJ fragmentation. Accordingly, MACF1 deficiency results in reduced muscle excitability and disorganized triads, leaving voltage-activated sarcoplasmic reticulum Ca2+ release and maximal muscle force unchanged. Finally, adult MACF1-KO mice present an improved resistance to fatigue correlated with a strong increase in mitochondria biogenesis.
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Affiliation(s)
- Alireza Ghasemizadeh
- Institut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon ILyon CedexFrance
| | - Emilie Christin
- Institut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon ILyon CedexFrance
| | - Alexandre Guiraud
- Institut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon ILyon CedexFrance
| | - Nathalie Couturier
- Institut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon ILyon CedexFrance
| | - Marie Abitbol
- Institut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon ILyon CedexFrance
- Université Marcy l’Etoile, VetAgro SupLyonFrance
| | - Valerie Risson
- Institut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon ILyon CedexFrance
| | - Emmanuelle Girard
- Institut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon ILyon CedexFrance
| | - Christophe Jagla
- GReD Laboratory, Clermont-Auvergne University, INSERM U1103, CNRSClermont-FerrandFrance
| | - Cedric Soler
- GReD Laboratory, Clermont-Auvergne University, INSERM U1103, CNRSClermont-FerrandFrance
| | - Lilia Laddada
- GReD Laboratory, Clermont-Auvergne University, INSERM U1103, CNRSClermont-FerrandFrance
| | - Colline Sanchez
- Institut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon ILyon CedexFrance
| | - Francisco-Ignacio Jaque-Fernandez
- Institut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon ILyon CedexFrance
| | - Vincent Jacquemond
- Institut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon ILyon CedexFrance
| | - Jean-Luc Thomas
- Institut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon ILyon CedexFrance
| | - Marine Lanfranchi
- Institut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon ILyon CedexFrance
| | - Julien Courchet
- Institut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon ILyon CedexFrance
| | - Julien Gondin
- Institut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon ILyon CedexFrance
| | - Laurent Schaeffer
- Institut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon ILyon CedexFrance
| | - Vincent Gache
- Institut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon ILyon CedexFrance
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10
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Battey E, Furrer R, Ross J, Handschin C, Ochala J, Stroud MJ. PGC-1α regulates myonuclear accretion after moderate endurance training. J Cell Physiol 2021; 237:696-705. [PMID: 34322871 DOI: 10.1002/jcp.30539] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 07/09/2021] [Accepted: 07/19/2021] [Indexed: 12/27/2022]
Abstract
The transcriptional demands of skeletal muscle fibres are high and require hundreds of nuclei (myonuclei) to produce specialised contractile machinery and multiple mitochondria along their length. Each myonucleus spatially regulates gene expression in a finite volume of cytoplasm, termed the myonuclear domain (MND), which positively correlates with fibre cross-sectional area (CSA). Endurance training triggers adaptive responses in skeletal muscle, including myonuclear accretion, decreased MND sizes and increased expression of the transcription co-activator peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α). Previous work has shown that overexpression of PGC-1α in skeletal muscle regulates mitochondrial biogenesis, myonuclear accretion and MND volume. However, whether PGC-1α is critical for these processes in adaptation to endurance training remained unclear. To test this, we evaluated myonuclear distribution and organisation in endurance-trained wild-type mice and mice lacking PGC-1α in skeletal muscle (PGC-1α mKO). Here, we show a differential myonuclear accretion response to endurance training that is governed by PGC-1α and is dependent on muscle fibre size. The positive relationship of MND size and muscle fibre CSA trended towards a stronger correlation in PGC-1a mKO versus control after endurance training, suggesting that myonuclear accretion was slightly affected with increasing fibre CSA in PGC-1α mKO. However, in larger fibres, the relationship between MND and CSA was significantly altered in trained versus sedentary PGC-1α mKO, suggesting that PGC-1α is critical for myonuclear accretion in these fibres. Accordingly, there was a negative correlation between the nuclear number and CSA, suggesting that in larger fibres myonuclear numbers fail to scale with CSA. Our findings suggest that PGC-1α is an important contributor to myonuclear accretion following moderate-intensity endurance training. This may contribute to the adaptive response to endurance training by enabling a sufficient rate of transcription of genes required for mitochondrial biogenesis.
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Affiliation(s)
- Edmund Battey
- Centre of Human and Applied Physiological Sciences, School of Basic and Medical Biosciences, Faculty of Life Sciences & Medicine, King's College London, London, UK.,British Heart Foundation Centre of Research Excellence, School of Cardiovascular Medicine and Sciences, Faculty of Life Sciences & Medicine, King's College London, London, UK
| | | | - Jacob Ross
- British Heart Foundation Centre of Research Excellence, School of Cardiovascular Medicine and Sciences, Faculty of Life Sciences & Medicine, King's College London, London, UK
| | | | - Julien Ochala
- Centre of Human and Applied Physiological Sciences, School of Basic and Medical Biosciences, Faculty of Life Sciences & Medicine, King's College London, London, UK.,Randall Centre for Cell and Molecular Biophysics, School of Basic & Medical Biosciences, Faculty of Life Sciences & Medicine, Guy's Campus, King's College London, London, UK.,Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Matthew J Stroud
- British Heart Foundation Centre of Research Excellence, School of Cardiovascular Medicine and Sciences, Faculty of Life Sciences & Medicine, King's College London, London, UK
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11
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Squarzoni S, Schena E, Sabatelli P, Mattioli E, Capanni C, Cenni V, D'Apice MR, Andrenacci D, Sarli G, Pellegrino V, Festa A, Baruffaldi F, Storci G, Bonafè M, Barboni C, Sanapo M, Zaghini A, Lattanzi G. Interleukin-6 neutralization ameliorates symptoms in prematurely aged mice. Aging Cell 2021; 20:e13285. [PMID: 33393189 PMCID: PMC7811841 DOI: 10.1111/acel.13285] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 10/23/2020] [Accepted: 11/14/2020] [Indexed: 12/17/2022] Open
Abstract
Hutchinson-Gilford progeria syndrome (HGPS) causes premature aging in children, with adipose tissue, skin and bone deterioration, and cardiovascular impairment. In HGPS cells and mouse models, high levels of interleukin-6, an inflammatory cytokine linked to aging processes, have been detected. Here, we show that inhibition of interleukin-6 activity by tocilizumab, a neutralizing antibody raised against interleukin-6 receptors, counteracts progeroid features in both HGPS fibroblasts and LmnaG609G / G609G progeroid mice. Tocilizumab treatment limits the accumulation of progerin, the toxic protein produced in HGPS cells, rescues nuclear envelope and chromatin abnormalities, and attenuates the hyperactivated DNA damage response. In vivo administration of tocilizumab reduces aortic lesions and adipose tissue dystrophy, delays the onset of lipodystrophy and kyphosis, avoids motor impairment, and preserves a good quality of life in progeroid mice. This work identifies tocilizumab as a valuable tool in HGPS therapy and, speculatively, in the treatment of a variety of aging-related disorders.
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Affiliation(s)
- Stefano Squarzoni
- CNR Institute of Molecular Genetics “Luigi Luca Cavalli‐Sforza” Unit of Bologna Bologna Italy
- IRCCS Istituto Ortopedico Rizzoli Bologna Italy
| | - Elisa Schena
- CNR Institute of Molecular Genetics “Luigi Luca Cavalli‐Sforza” Unit of Bologna Bologna Italy
- IRCCS Istituto Ortopedico Rizzoli Bologna Italy
| | - Patrizia Sabatelli
- CNR Institute of Molecular Genetics “Luigi Luca Cavalli‐Sforza” Unit of Bologna Bologna Italy
- IRCCS Istituto Ortopedico Rizzoli Bologna Italy
| | - Elisabetta Mattioli
- CNR Institute of Molecular Genetics “Luigi Luca Cavalli‐Sforza” Unit of Bologna Bologna Italy
- IRCCS Istituto Ortopedico Rizzoli Bologna Italy
| | - Cristina Capanni
- CNR Institute of Molecular Genetics “Luigi Luca Cavalli‐Sforza” Unit of Bologna Bologna Italy
- IRCCS Istituto Ortopedico Rizzoli Bologna Italy
| | - Vittoria Cenni
- CNR Institute of Molecular Genetics “Luigi Luca Cavalli‐Sforza” Unit of Bologna Bologna Italy
- IRCCS Istituto Ortopedico Rizzoli Bologna Italy
| | | | - Davide Andrenacci
- CNR Institute of Molecular Genetics “Luigi Luca Cavalli‐Sforza” Unit of Bologna Bologna Italy
- IRCCS Istituto Ortopedico Rizzoli Bologna Italy
| | - Giuseppe Sarli
- Department of Veterinary Medical Sciences University of Bologna Bologna Italy
| | - Valeria Pellegrino
- Department of Veterinary Medical Sciences University of Bologna Bologna Italy
| | - Anna Festa
- Laboratory of Medical Technology IRCCS Istituto Ortopedico Rizzoli Bologna Italy
| | - Fabio Baruffaldi
- Laboratory of Medical Technology IRCCS Istituto Ortopedico Rizzoli Bologna Italy
| | - Gianluca Storci
- Department of Experimental, Diagnostic and Specialty Medicine University of Bologna Bologna Italy
| | - Massimiliano Bonafè
- Department of Experimental, Diagnostic and Specialty Medicine University of Bologna Bologna Italy
| | - Catia Barboni
- Department of Veterinary Medical Sciences University of Bologna Bologna Italy
| | - Mara Sanapo
- Department of Veterinary Medical Sciences University of Bologna Bologna Italy
| | - Anna Zaghini
- Department of Veterinary Medical Sciences University of Bologna Bologna Italy
| | - Giovanna Lattanzi
- CNR Institute of Molecular Genetics “Luigi Luca Cavalli‐Sforza” Unit of Bologna Bologna Italy
- IRCCS Istituto Ortopedico Rizzoli Bologna Italy
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12
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Using nuclear envelope mutations to explore age-related skeletal muscle weakness. Clin Sci (Lond) 2020; 134:2177-2187. [PMID: 32844998 PMCID: PMC7450176 DOI: 10.1042/cs20190066] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 08/04/2020] [Accepted: 08/17/2020] [Indexed: 12/19/2022]
Abstract
Skeletal muscle weakness is an important determinant of age-related declines in independence and quality of life but its causes remain unclear. Accelerated ageing syndromes such as Hutchinson-Gilford Progerin Syndrome, caused by mutations in genes encoding nuclear envelope proteins, have been extensively studied to aid our understanding of the normal biological ageing process. Like several other pathologies associated with genetic defects to nuclear envelope proteins including Emery-Dreifuss muscular dystrophy, Limb-Girdle muscular dystrophy and congenital muscular dystrophy, these disorders can lead to severe muscle dysfunction. Here, we first describe the structure and function of nuclear envelope proteins, and then review the mechanisms by which mutations in genes encoding nuclear envelope proteins induce premature ageing diseases and muscle pathologies. In doing so, we highlight the potential importance of such genes in processes leading to skeletal muscle weakness in old age.
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13
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Cramer AAW, Prasad V, Eftestøl E, Song T, Hansson KA, Dugdale HF, Sadayappan S, Ochala J, Gundersen K, Millay DP. Nuclear numbers in syncytial muscle fibers promote size but limit the development of larger myonuclear domains. Nat Commun 2020; 11:6287. [PMID: 33293533 PMCID: PMC7722938 DOI: 10.1038/s41467-020-20058-7] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Accepted: 10/30/2020] [Indexed: 12/11/2022] Open
Abstract
Mammalian cells exhibit remarkable diversity in cell size, but the factors that regulate establishment and maintenance of these sizes remain poorly understood. This is especially true for skeletal muscle, comprised of syncytial myofibers that each accrue hundreds of nuclei during development. Here, we directly explore the assumed causal relationship between multinucleation and establishment of normal size through titration of myonuclear numbers during mouse neonatal development. Three independent mouse models, where myonuclear numbers were reduced by 75, 55, or 25%, led to the discovery that myonuclei possess a reserve capacity to support larger functional cytoplasmic volumes in developing myofibers. Surprisingly, the results revealed an inverse relationship between nuclei numbers and reserve capacity. We propose that as myonuclear numbers increase, the range of transcriptional return on a per nuclear basis in myofibers diminishes, which accounts for both the absolute reliance developing myofibers have on nuclear accrual to establish size, and the limits of adaptability in adult skeletal muscle.
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Affiliation(s)
- Alyssa A W Cramer
- Division of Molecular Cardiovascular Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA
| | - Vikram Prasad
- Division of Molecular Cardiovascular Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA
| | - Einar Eftestøl
- Division of Molecular Cardiovascular Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA
- Department of Biosciences, University of Oslo, Oslo, Norway
| | - Taejeong Song
- Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati College of Medicine, Cincinnati, OH, 45229, USA
| | - Kenth-Arne Hansson
- Department of Biosciences, University of Oslo, Oslo, Norway
- Center for Integrative Neuroplasticity (CINPLA), Department of Biosciences, University of Oslo, Oslo, Norway
| | - Hannah F Dugdale
- Center of Human and Applied Physiological Sciences, School of Basic and Medical Biosciences, Faculty of Life Sciences & Medicine, King's College London, London, UK
| | - Sakthivel Sadayappan
- Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati College of Medicine, Cincinnati, OH, 45229, USA
| | - Julien Ochala
- Center of Human and Applied Physiological Sciences, School of Basic and Medical Biosciences, Faculty of Life Sciences & Medicine, King's College London, London, UK
- Randall Center for Cell and Molecular Biophysics, School of Basic & Medical Biosciences, Faculty of Life Sciences & Medicine, Guy's Campus, King's College London, London, UK
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Douglas P Millay
- Division of Molecular Cardiovascular Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA.
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, 45229, USA.
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14
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Ross JA, Tasfaout H, Levy Y, Morgan J, Cowling BS, Laporte J, Zanoteli E, Romero NB, Lowe DA, Jungbluth H, Lawlor MW, Mack DL, Ochala J. rAAV-related therapy fully rescues myonuclear and myofilament function in X-linked myotubular myopathy. Acta Neuropathol Commun 2020; 8:167. [PMID: 33076971 PMCID: PMC7574461 DOI: 10.1186/s40478-020-01048-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 10/02/2020] [Indexed: 01/17/2023] Open
Abstract
X-linked myotubular myopathy (XLMTM) is a life-threatening skeletal muscle disease caused by mutations in the MTM1 gene. XLMTM fibres display a population of nuclei mispositioned in the centre. In the present study, we aimed to explore whether positioning and overall distribution of nuclei affects cellular organization and contractile function, thereby contributing to muscle weakness in this disease. We also assessed whether gene therapy alters nuclear arrangement and function. We used tissue from human patients and animal models, including XLMTM dogs that had received increasing doses of recombinant AAV8 vector restoring MTM1 expression (rAAV8-cMTM1). We then used single isolated muscle fibres to analyze nuclear organization and contractile function. In addition to the expected mislocalization of nuclei in the centre of muscle fibres, a novel form of nuclear mispositioning was observed: irregular spacing between those located at the fibre periphery, and an overall increased number of nuclei, leading to dramatically smaller and inconsistent myonuclear domains. Nuclear mislocalization was associated with decreases in global nuclear synthetic activity, contractile protein content and intrinsic myofilament force production. A contractile deficit originating at the myofilaments, rather than mechanical interference by centrally positioned nuclei, was supported by experiments in regenerated mouse muscle. Systemic administration of rAAV8-cMTM1 at doses higher than 2.5 × 1013 vg kg−1 allowed a full rescue of all these cellular defects in XLMTM dogs. Altogether, these findings identify previously unrecognized pathological mechanisms in human and animal XLMTM, associated with myonuclear defects and contractile filament function. These defects can be reversed by gene therapy restoring MTM1 expression in dogs with XLMTM.
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15
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Bae JH, Hong M, Jeong HJ, Kim H, Lee SJ, Ryu D, Bae GU, Cho SC, Lee YS, Krauss RS, Kang JS. Satellite cell-specific ablation of Cdon impairs integrin activation, FGF signalling, and muscle regeneration. J Cachexia Sarcopenia Muscle 2020; 11:1089-1103. [PMID: 32103583 PMCID: PMC7432598 DOI: 10.1002/jcsm.12563] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Revised: 12/04/2019] [Accepted: 02/09/2020] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Perturbation in cell adhesion and growth factor signalling in satellite cells results in decreased muscle regenerative capacity. Cdon (also called Cdo) is a component of cell adhesion complexes implicated in myogenic differentiation, but its role in muscle regeneration remains to be determined. METHODS We generated inducible satellite cell-specific Cdon ablation in mice by utilizing a conditional Cdon allele and Pax7 CreERT2 . To induce Cdon ablation, mice were intraperitoneally injected with tamoxifen (tmx). Using cardiotoxin-induced muscle injury, the effect of Cdon depletion on satellite cell function was examined by histochemistry, immunostaining, and 5-ethynyl-2'-deoxyuridine (EdU) incorporation assay. Isolated myofibers or myoblasts were utilized to determine stem cell function and senescence. To determine pathways related to Cdon deletion, injured muscles were subjected to RNA sequencing analysis. RESULTS Satellite cell-specific Cdon ablation causes impaired muscle regeneration with fibrosis, likely attributable to decreased proliferation, and senescence, of satellite cells. Cultured Cdon-depleted myofibers exhibited 32 ± 9.6% of EdU-positive satellite cells compared with 58 ± 4.4% satellite cells in control myofibers (P < 0.05). About 32.5 ± 3.7% Cdon-ablated myoblasts were positive for senescence-associated β-galactosidase (SA-β-gal) while only 3.6 ± 0.5% of control satellite cells were positive (P < 0.001). Transcriptome analysis of muscles at post-injury Day 4 revealed alterations in genes related to mitogen-activated protein kinase signalling (P < 8.29 e-5 ) and extracellular matrix (P < 2.65 e-24 ). Consistent with this, Cdon-depleted tibialis anterior muscles had reduced phosphorylated extracellular signal-regulated kinase (p-ERK) protein levels and expression of ERK targets, such as Fos (0.23-fold) and Egr1 (0.31-fold), relative to mock-treated control muscles (P < 0.001). Cdon-depleted myoblasts exhibited impaired ERK activation in response to basic fibroblast growth factor. Cdon ablation resulted in decreased and/or mislocalized integrin β1 activation in satellite cells (weak or mislocalized integrin1 in tmx = 38.7 ± 1.9%, mock = 21.5 ± 6%, P < 0.05), previously linked with reduced fibroblast growth factor (FGF) responsiveness in aged satellite cells. In mechanistic studies, Cdon interacted with and regulated cell surface localization of FGFR1 and FGFR4, likely contributing to FGF responsiveness of satellite cells. Satellite cells from a progeria model, Zmpste24-/- myofibers, showed decreased Cdon levels (Cdon-positive cells in Zmpste24-/- = 63.3 ± 11%, wild type = 90 ± 7.7%, P < 0.05) and integrin β1 activation (weak or mislocalized integrin β1 in Zmpste24-/- = 64 ± 6.9%, wild type = 17.4 ± 5.9%, P < 0.01). CONCLUSIONS Cdon deficiency in satellite cells causes impaired proliferation of satellite cells and muscle regeneration via aberrant integrin and FGFR signalling.
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Affiliation(s)
- Ju-Hyeon Bae
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea.,Single Cell Network Research Center, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea
| | - Mingi Hong
- Department of Cell, Developmental, and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Hyeon-Ju Jeong
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea.,Single Cell Network Research Center, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea
| | - Hyebeen Kim
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea.,Single Cell Network Research Center, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea
| | - Sang-Jin Lee
- Research Institute of Pharmaceutical Science, College of Pharmacy, Sookmyung Women's University, Seoul, Republic of Korea
| | - Dongryeol Ryu
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea.,Samsung Biomedical Research Institute, Samsung Medical Center, Seoul, Republic of Korea
| | - Gyu-Un Bae
- Research Institute of Pharmaceutical Science, College of Pharmacy, Sookmyung Women's University, Seoul, Republic of Korea
| | - Sung Chun Cho
- Well Aging Research Center, DGIST, Daegu, Republic of Korea
| | - Young-Sam Lee
- Well Aging Research Center, DGIST, Daegu, Republic of Korea.,Department of New Biology, DGIST, Daegu, Republic of Korea
| | - Robert S Krauss
- Department of Cell, Developmental, and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Jong-Sun Kang
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea.,Single Cell Network Research Center, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea.,Samsung Biomedical Research Institute, Samsung Medical Center, Seoul, Republic of Korea
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16
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Beedour R, Ross JA, Levy Y, Ochala J. Effect of PGC1-beta ablation on myonuclear organisation. J Muscle Res Cell Motil 2019; 40:335-341. [PMID: 31485877 PMCID: PMC6831542 DOI: 10.1007/s10974-019-09549-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Skeletal muscle fibres are large, elongated multinucleated cells. Each nucleus within a myofibre is responsible for generating gene products for a finite volume of cytoplasm-the myonuclear domain (MND). Variation in MND sizes during atrophy, hypertrophy and disease states, are common. The factors that contribute to definitive MND sizes are not yet fully understood. Previous work has shown that peroxisome proliferator-activated receptor gamma coactivator 1α (PGC1-α) modulates MND volume, presumably to support increased biogenesis of mitochondria. The transcriptional co-regulator peroxisome proliferator-activated receptor gamma coactivator 1β (PGC1-β) is a homologue of PGC1-α with overlapping functions. To investigate the role of this protein in MND size regulation, we studied a mouse skeletal muscle specific knockout (cKO). Myofibres were isolated from the fast twitch extensor digitorum longus (EDL) muscle, membrane-permeabilised and analysed in 3 dimensions using confocal microscopy. PGC1-β ablation resulted in no significant difference in MND size between cKO and wild type (WT) mice, however, subtle differences in nuclear morphology were observed. To determine whether these nuclear shape changes were associated with alterations in global transcriptional activity, acetyl histone H3 immunostaining was carried out. We found there was no significant difference in nuclear fluorescence intensity between the two genotypes. Overall, the results suggest that PGC-1α and PGC-1β play different roles in regulating nuclear organisation in skeletal muscle; however, further work is required to pinpoint their exact functions.
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Affiliation(s)
- Ryan Beedour
- Faculty of Life Sciences & Medicine, School of Basic and Medical Biosciences, Centre of Human and Applied Physiological Sciences, King's College London, London, UK
| | - Jacob A Ross
- Faculty of Life Sciences & Medicine, School of Basic and Medical Biosciences, Centre of Human and Applied Physiological Sciences, King's College London, London, UK
| | - Yotam Levy
- Faculty of Life Sciences & Medicine, School of Basic and Medical Biosciences, Centre of Human and Applied Physiological Sciences, King's College London, London, UK
| | - Julien Ochala
- Faculty of Life Sciences & Medicine, School of Basic and Medical Biosciences, Centre of Human and Applied Physiological Sciences, King's College London, London, UK.
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17
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Ross JA, Levy Y, Ripolone M, Kolb JS, Turmaine M, Holt M, Lindqvist J, Claeys KG, Weis J, Monforte M, Tasca G, Moggio M, Figeac N, Zammit PS, Jungbluth H, Fiorillo C, Vissing J, Witting N, Granzier H, Zanoteli E, Hardeman EC, Wallgren-Pettersson C, Ochala J. Impairments in contractility and cytoskeletal organisation cause nuclear defects in nemaline myopathy. Acta Neuropathol 2019; 138:477-495. [PMID: 31218456 PMCID: PMC6689292 DOI: 10.1007/s00401-019-02034-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 05/28/2019] [Accepted: 06/05/2019] [Indexed: 02/07/2023]
Abstract
Nemaline myopathy (NM) is a skeletal muscle disorder caused by mutations in genes that are generally involved in muscle contraction, in particular those related to the structure and/or regulation of the thin filament. Many pathogenic aspects of this disease remain largely unclear. Here, we report novel pathological defects in skeletal muscle fibres of mouse models and patients with NM: irregular spacing and morphology of nuclei; disrupted nuclear envelope; altered chromatin arrangement; and disorganisation of the cortical cytoskeleton. Impairments in contractility are the primary cause of these nuclear defects. We also establish the role of microtubule organisation in determining nuclear morphology, a phenomenon which is likely to contribute to nuclear alterations in this disease. Our results overlap with findings in diseases caused directly by mutations in nuclear envelope or cytoskeletal proteins. Given the important role of nuclear shape and envelope in regulating gene expression, and the cytoskeleton in maintaining muscle fibre integrity, our findings are likely to explain some of the hallmarks of NM, including contractile filament disarray, altered mechanical properties and broad transcriptional alterations.
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