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Feng L, Chen Z, Bian H. Skeletal muscle: molecular structure, myogenesis, biological functions, and diseases. MedComm (Beijing) 2024; 5:e649. [PMID: 38988494 PMCID: PMC11234433 DOI: 10.1002/mco2.649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2023] [Revised: 06/13/2024] [Accepted: 06/17/2024] [Indexed: 07/12/2024] Open
Abstract
Skeletal muscle is an important motor organ with multinucleated myofibers as its smallest cellular units. Myofibers are formed after undergoing cell differentiation, cell-cell fusion, myonuclei migration, and myofibril crosslinking among other processes and undergo morphological and functional changes or lesions after being stimulated by internal or external factors. The above processes are collectively referred to as myogenesis. After myofibers mature, the function and behavior of skeletal muscle are closely related to the voluntary movement of the body. In this review, we systematically and comprehensively discuss the physiological and pathological processes associated with skeletal muscles from five perspectives: molecule basis, myogenesis, biological function, adaptive changes, and myopathy. In the molecular structure and myogenesis sections, we gave a brief overview, focusing on skeletal muscle-specific fusogens and nuclei-related behaviors including cell-cell fusion and myonuclei localization. Subsequently, we discussed the three biological functions of skeletal muscle (muscle contraction, thermogenesis, and myokines secretion) and its response to stimulation (atrophy, hypertrophy, and regeneration), and finally settled on myopathy. In general, the integration of these contents provides a holistic perspective, which helps to further elucidate the structure, characteristics, and functions of skeletal muscle.
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Affiliation(s)
- Lan‐Ting Feng
- Department of Cell Biology & National Translational Science Center for Molecular MedicineNational Key Laboratory of New Drug Discovery and Development for Major DiseasesFourth Military Medical UniversityXi'anChina
| | - Zhi‐Nan Chen
- Department of Cell Biology & National Translational Science Center for Molecular MedicineNational Key Laboratory of New Drug Discovery and Development for Major DiseasesFourth Military Medical UniversityXi'anChina
| | - Huijie Bian
- Department of Cell Biology & National Translational Science Center for Molecular MedicineNational Key Laboratory of New Drug Discovery and Development for Major DiseasesFourth Military Medical UniversityXi'anChina
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2
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de Albuquerque ALA, Chadanowicz JK, Giudicelli GC, Staub ALP, Weber AC, Silva JMDS, Becker MM, Kowalski TW, Siebert M, Saute JAM. Serum myostatin as a candidate disease severity and progression biomarker of spinal muscular atrophy. Brain Commun 2024; 6:fcae062. [PMID: 38487549 PMCID: PMC10939446 DOI: 10.1093/braincomms/fcae062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 01/18/2024] [Accepted: 02/27/2024] [Indexed: 03/17/2024] Open
Abstract
The identification of biomarkers for spinal muscular atrophy is crucial for predicting disease progression, severity, and response to new disease-modifying therapies. This study aimed to investigate the role of serum levels of myostatin and follistatin as biomarkers for spinal muscular atrophy, considering muscle atrophy secondary to denervation as the main clinical manifestation of the disease. The study evaluated the differential gene expression of myostatin and follistatin in a lesional model of gastrocnemius denervation in mice, as well as in a meta-analysis of three datasets in transgenic mice models of spinal muscular atrophy, and in two studies involving humans with spinal muscular atrophy. Subsequently, a case-control study involving 27 spinal muscular atrophy patients and 27 controls was conducted, followed by a 12-month cohort study with 25 spinal muscular atrophy cases. Serum levels of myostatin and follistatin were analysed using enzyme-linked immunosorbent assay at a single centre in southern Brazil. Skeletal muscle gene expression of myostatin decreased and of follistatin increased following lesional muscle denervation in mice, consistent with findings in the spinal muscular atrophy transgenic mice meta-analysis and in the iliopsoas muscle of five patients with spinal muscular atrophy type 1. Median serum myostatin levels were significantly lower in spinal muscular atrophy patients (98 pg/mL; 5-157) compared to controls (412 pg/mL; 299-730) (P < 0.001). Lower myostatin levels were associated with greater disease severity based on clinician-rated outcomes (Rho = 0.493-0.812; P < 0.05). After 12 months, there was a further reduction in myostatin levels among spinal muscular atrophy cases (P = 0.021). Follistatin levels did not differ between cases and controls, and no significant changes were observed over time. The follistatin:myostatin ratio was significantly increased in spinal muscular atrophy subjects and inversely correlated with motor severity. Serum myostatin levels show promise as a novel biomarker for evaluating the severity and progression of spinal muscular atrophy. The decrease in myostatin levels and the subsequent favourable environment for muscle growth may be attributed to denervation caused by motor neuron dysfunction.
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Affiliation(s)
- Ana Letícia Amorim de Albuquerque
- Graduate Program in Medicine, Medical Sciences, Federal University of Rio Grande do Sul, Porto Alegre 90035-003, Brazil
- Clinical Neurogenetics research group, Hospital de Clínicas de Porto Alegre, Porto Alegre 90035-007, Brazil
| | - Júlia Kersting Chadanowicz
- Clinical Neurogenetics research group, Hospital de Clínicas de Porto Alegre, Porto Alegre 90035-007, Brazil
| | - Giovanna Câmara Giudicelli
- Bioinformatics core, Hospital de Clínicas de Porto Alegre, Porto Alegre 90035-007, Brazil
- Graduate Program in Genetics and Molecular Biology, Federal University of Rio Grande do Sul, Porto Alegre 91501-970, Brazil
| | - Ana Lucia Portella Staub
- Clinical Neurogenetics research group, Hospital de Clínicas de Porto Alegre, Porto Alegre 90035-007, Brazil
| | - Arthur Carpeggiani Weber
- Clinical Neurogenetics research group, Hospital de Clínicas de Porto Alegre, Porto Alegre 90035-007, Brazil
| | | | | | - Thayne Woycinck Kowalski
- Bioinformatics core, Hospital de Clínicas de Porto Alegre, Porto Alegre 90035-007, Brazil
- Graduate Program in Genetics and Molecular Biology, Federal University of Rio Grande do Sul, Porto Alegre 91501-970, Brazil
- Medical Genetics Service, Hospital de Clínicas de Porto Alegre, Porto Alegre 90035-007, Brazil
| | - Marina Siebert
- Unit of Laboratorial Research, Experimental Research Center, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre 90035-007, Brazil
- Graduate Program in Gastroenterology and Hepatology, Federal University of Rio Grande do Sul, Porto Alegre 90035-003, Brazil
| | - Jonas Alex Morales Saute
- Graduate Program in Medicine, Medical Sciences, Federal University of Rio Grande do Sul, Porto Alegre 90035-003, Brazil
- Clinical Neurogenetics research group, Hospital de Clínicas de Porto Alegre, Porto Alegre 90035-007, Brazil
- Medical Genetics Service, Hospital de Clínicas de Porto Alegre, Porto Alegre 90035-007, Brazil
- Department of Internal Medicine, Federal University of Rio Grande do Sul, Porto Alegre 90035-003, Brazil
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3
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Bakooshli MA, Wang YX, Monti E, Su S, Kraft P, Nalbandian M, Alexandrova L, Wheeler JR, Vogel H, Blau HM. Regeneration of neuromuscular synapses after acute and chronic denervation by inhibiting the gerozyme 15-prostaglandin dehydrogenase. Sci Transl Med 2023; 15:eadg1485. [PMID: 37820010 PMCID: PMC10763629 DOI: 10.1126/scitranslmed.adg1485] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Accepted: 09/22/2023] [Indexed: 10/13/2023]
Abstract
To date, there are no approved treatments for the diminished strength and paralysis that result from the loss of peripheral nerve function due to trauma, heritable neuromuscular diseases, or aging. Here, we showed that denervation resulting from transection of the sciatic nerve triggered a marked increase in the prostaglandin-degrading enzyme 15-hydroxyprostaglandin dehydrogenase (15-PGDH) in skeletal muscle in mice, providing evidence that injury drives early expression of this aging-associated enzyme or gerozyme. Treating mice with a small-molecule inhibitor of 15-PGDH promoted regeneration of motor axons and formation of neuromuscular synapses leading to an acceleration in recovery of force after an acute nerve crush injury. In aged mice with chronic denervation of muscles, treatment with the 15-PGDH inhibitor increased motor neuron viability and restored neuromuscular junctions and function. These presynaptic changes synergized with previously reported muscle tissue remodeling to result in a marked increase in the strength of aged muscles. We further found that 15-PGDH aggregates defined the target fibers that are histopathologic hallmarks of human neurogenic myopathies, suggesting that the gerozyme may be involved in their etiology. Our data suggest that inhibition of 15-PGDH may constitute a therapeutic strategy to physiologically boost prostaglandin E2, restore neuromuscular connectivity, and promote recovery of strength after acute or chronic denervation due to injury, disease, or aging.
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Affiliation(s)
- Mohsen A. Bakooshli
- Baxter Laboratory for Stem Cell Biology, Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Yu Xin Wang
- Baxter Laboratory for Stem Cell Biology, Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
- Center for Genetic Disorders and Aging, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Elena Monti
- Baxter Laboratory for Stem Cell Biology, Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Shiqi Su
- Baxter Laboratory for Stem Cell Biology, Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Peggy Kraft
- Baxter Laboratory for Stem Cell Biology, Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Minas Nalbandian
- Baxter Laboratory for Stem Cell Biology, Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Ludmila Alexandrova
- Vincent Coates Foundation Mass Spectrometry Laboratory, Stanford University, Stanford, CA 94305, USA
| | - Joshua R. Wheeler
- Department of Pathology, Stanford University, Stanford, CA 94305, USA
- Department of Neuropathology, Stanford University, Stanford, CA 94305, USA
| | - Hannes Vogel
- Department of Pathology, Stanford University, Stanford, CA 94305, USA
- Department of Neuropathology, Stanford University, Stanford, CA 94305, USA
| | - Helen M. Blau
- Baxter Laboratory for Stem Cell Biology, Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
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4
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Jha NN, Kim JK, Her YR, Monani UR. Muscle: an independent contributor to the neuromuscular spinal muscular atrophy disease phenotype. JCI Insight 2023; 8:e171878. [PMID: 37737261 PMCID: PMC10561723 DOI: 10.1172/jci.insight.171878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/23/2023] Open
Abstract
Spinal muscular atrophy (SMA) is a pediatric-onset neuromuscular disorder caused by insufficient survival motor neuron (SMN) protein. SMN restorative therapies are now approved for the treatment of SMA; however, they are not curative, likely due to a combination of imperfect treatment timing, inadequate SMN augmentation, and failure to optimally target relevant organs. Here, we consider the implications of imperfect treatment administration, focusing specifically on outcomes for skeletal muscle. We examine the evidence that muscle plays a contributing role in driving neuromuscular dysfunction in SMA. Next, we discuss how SMN might regulate the health of myofibers and their progenitors. Finally, we speculate on therapeutic outcomes of failing to raise muscle SMN to healthful levels and present strategies to restore function to this tissue to ensure better treatment results.
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Affiliation(s)
- Narendra N. Jha
- Department of Neurology
- Center for Motor Neuron Biology and Disease, and
| | - Jeong-Ki Kim
- Department of Neurology
- Center for Motor Neuron Biology and Disease, and
| | - Yoon-Ra Her
- Department of Neurology
- Center for Motor Neuron Biology and Disease, and
| | - Umrao R. Monani
- Department of Neurology
- Center for Motor Neuron Biology and Disease, and
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, New York, USA
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5
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Maeno T, Arimatsu R, Ojima K, Yamaya Y, Imakyure H, Watanabe N, Komiya Y, Kobayashi K, Nakamura M, Nishimura T, Tatsumi R, Suzuki T. Netrin-4 synthesized in satellite cell-derived myoblasts stimulates autonomous fusion. Exp Cell Res 2023; 430:113698. [PMID: 37437770 DOI: 10.1016/j.yexcr.2023.113698] [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: 12/08/2022] [Revised: 06/20/2023] [Accepted: 06/23/2023] [Indexed: 07/14/2023]
Abstract
Satellite cells are indispensable for skeletal muscle regeneration and hypertrophy by forming nascent myofibers (myotubes). They synthesize multi-potent modulator netrins (secreted subtypes: netrin-1, -3, and -4), originally found as classical neural axon guidance molecules. While netrin-1 and -3 have key roles in myogenic differentiation, the physiological significance of netrin-4 is still unclear. This study examined whether netrin-4 regulates myofiber type commitment and myotube formation. Initially, the expression profiles indicated that satellite cells isolated from the extensor digitorum longus muscle (EDL muscle: fast-twitch myofiber-abundant) expressed slightly more netrin-4 than the soleus muscle (slow-type abundant) cells. As netrin-4 knockdown inhibited both slow- and fast-type myotube formation, netrin-4 may not directly regulate myofiber type commitment. However, netrin-4 knockdown in satellite cell-derived myoblasts reduced the myotube fusion index, while exogenous netrin-4 promoted myotube formation, even though netrin-4 expression level was maximum during the initiation stage of myogenic differentiation. Furthermore, netrin-4 knockdown also inhibited MyoD (a master transcriptional factor of myogenesis) and Myomixer (a myoblast fusogenic molecule) expression. These data suggest that satellite cells synthesize netrin-4 during myogenic differentiation initiation to promote their own fusion, stimulating the MyoD-Myomixer signaling axis.
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Affiliation(s)
- Takahiro Maeno
- Laboratory of Muscle and Meat Science, Department of Animal and Marine Bioresource Sciences, Research Faculty of Agriculture, Graduate School of Agriculture, Kyushu University, Fukuoka, Japan
| | - Rio Arimatsu
- Laboratory of Cell and Tissue Biology, Research Faculty of Agriculture, Graduate School of Agriculture, Hokkaido University, Sapporo, Japan
| | - Koichi Ojima
- Muscle Biology Research Unit, Division of Animal Products Research, Institute of Livestock and Grassland Science, NARO, Tsukuba, Japan
| | - Yuki Yamaya
- Laboratory of Cell and Tissue Biology, Research Faculty of Agriculture, Graduate School of Agriculture, Hokkaido University, Sapporo, Japan
| | - Hikaru Imakyure
- Laboratory of Muscle and Meat Science, Department of Animal and Marine Bioresource Sciences, Research Faculty of Agriculture, Graduate School of Agriculture, Kyushu University, Fukuoka, Japan
| | - Naruha Watanabe
- Laboratory of Muscle and Meat Science, Department of Animal and Marine Bioresource Sciences, Research Faculty of Agriculture, Graduate School of Agriculture, Kyushu University, Fukuoka, Japan
| | - Yusuke Komiya
- Department of Animal Science, School of Veterinary Medicine, Kitasato University, Towada, Japan
| | - Ken Kobayashi
- Laboratory of Cell and Tissue Biology, Research Faculty of Agriculture, Graduate School of Agriculture, Hokkaido University, Sapporo, Japan
| | - Mako Nakamura
- Laboratory of Muscle and Meat Science, Department of Animal and Marine Bioresource Sciences, Research Faculty of Agriculture, Graduate School of Agriculture, Kyushu University, Fukuoka, Japan
| | - Takanori Nishimura
- Laboratory of Cell and Tissue Biology, Research Faculty of Agriculture, Graduate School of Agriculture, Hokkaido University, Sapporo, Japan
| | - Ryuichi Tatsumi
- Laboratory of Muscle and Meat Science, Department of Animal and Marine Bioresource Sciences, Research Faculty of Agriculture, Graduate School of Agriculture, Kyushu University, Fukuoka, Japan
| | - Takahiro Suzuki
- Laboratory of Muscle and Meat Science, Department of Animal and Marine Bioresource Sciences, Research Faculty of Agriculture, Graduate School of Agriculture, Kyushu University, Fukuoka, Japan.
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6
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Kurosaka M, Hung YL, Machida S, Kohda K. IL-4 Signaling Promotes Myoblast Differentiation and Fusion by Enhancing the Expression of MyoD, Myogenin, and Myomerger. Cells 2023; 12:cells12091284. [PMID: 37174683 PMCID: PMC10177410 DOI: 10.3390/cells12091284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Revised: 04/20/2023] [Accepted: 04/27/2023] [Indexed: 05/15/2023] Open
Abstract
Myoblast fusion is essential for skeletal muscle development, growth, and regeneration. However, the molecular mechanisms underlying myoblast fusion and differentiation are not fully understood. Previously, we reported that interleukin-4 (IL-4) promotes myoblast fusion; therefore, we hypothesized that IL-4 signaling might regulate the expression of the molecules involved in myoblast fusion. In this study, we showed that in addition to fusion, IL-4 promoted the differentiation of C2C12 myoblast cells by inducing myoblast determination protein 1 (MyoD) and myogenin, both of which regulate the expression of myomerger and myomaker, the membrane proteins essential for myoblast fusion. Unexpectedly, IL-4 treatment increased the expression of myomerger, but not myomaker, in C2C12 cells. Knockdown of IL-4 receptor alpha (IL-4Rα) in C2C12 cells by small interfering RNA impaired myoblast fusion and differentiation. We also demonstrated a reduction in the expression of MyoD, myogenin, and myomerger by knockdown of IL-4Rα in C2C12 cells, while the expression level of myomaker remained unchanged. Finally, cell mixing assays and the restoration of myomerger expression partially rescued the impaired fusion in the IL-4Rα-knockdown C2C12 cells. Collectively, these results suggest that the IL-4/IL-4Rα axis promotes myoblast fusion and differentiation via the induction of myogenic regulatory factors, MyoD and myogenin, and myomerger.
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Affiliation(s)
- Mitsutoshi Kurosaka
- Department of Physiology, St. Marianna University School of Medicine, Kanagawa 216-8511, Japan
| | - Yung-Li Hung
- Institute of Health and Sports & Medicine, Juntendo University, Chiba 270-1695, Japan
| | - Shuichi Machida
- Institute of Health and Sports & Medicine, Juntendo University, Chiba 270-1695, Japan
- Graduate School of Health and Sports Science, Juntendo University, Chiba 270-1695, Japan
| | - Kazuhisa Kohda
- Department of Physiology, St. Marianna University School of Medicine, Kanagawa 216-8511, Japan
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7
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Khayrullina G, Alipio‐Gloria ZA, Deguise M, Gagnon S, Chehade L, Stinson M, Belous N, Bergman EM, Lischka FW, Rotty J, Dalgard CL, Kothary R, Johnson KA, Burnett BG. Survival motor neuron protein deficiency alters microglia reactivity. Glia 2022; 70:1337-1358. [PMID: 35373853 PMCID: PMC9081169 DOI: 10.1002/glia.24177] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 03/20/2022] [Accepted: 03/25/2022] [Indexed: 12/31/2022]
Abstract
Survival motor neuron (SMN) protein deficiency results in loss of alpha motor neurons and subsequent muscle atrophy in patients with spinal muscular atrophy (SMA). Reactive microglia have been reported in SMA mice and depleting microglia rescues the number of proprioceptive synapses, suggesting a role in SMA pathology. Here, we explore the contribution of lymphocytes on microglia reactivity in SMA mice and investigate how SMN deficiency alters the reactive profile of human induced pluripotent stem cell (iPSC)-derived microglia. We show that microglia adopt a reactive morphology in spinal cords of SMA mice. Ablating lymphocytes did not alter the reactive morphology of SMA microglia and did not improve the survival or motor function of SMA mice, indicating limited impact of peripheral immune cells on the SMA phenotype. We found iPSC-derived SMA microglia adopted an amoeboid morphology and displayed a reactive transcriptome profile, increased cell migration, and enhanced phagocytic activity. Importantly, cell morphology and electrophysiological properties of motor neurons were altered when they were incubated with conditioned media from SMA microglia. Together, these data reveal that SMN-deficient microglia adopt a reactive profile and exhibit an exaggerated inflammatory response with potential impact on SMA neuropathology.
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Affiliation(s)
- Guzal Khayrullina
- Department of Anatomy, Physiology, and GeneticsUniformed Services University of the Health Sciences, F. Edward Hebert School of MedicineBethesdaMarylandUSA
| | | | - Marc‐Olivier Deguise
- Regenerative Medicine ProgramOttawa Hospital Research InstituteOttawaOntarioCanada
- Department of Cellular and Molecular MedicineUniversity of OttawaOttawaOntarioCanada
- Centre for Neuromuscular DiseaseUniversity of OttawaOttawaOntarioCanada
- Department of PediatricsChildren's Hospital of Eastern OntarioOttawaOntarioCanada
| | - Sabrina Gagnon
- Regenerative Medicine ProgramOttawa Hospital Research InstituteOttawaOntarioCanada
| | - Lucia Chehade
- Regenerative Medicine ProgramOttawa Hospital Research InstituteOttawaOntarioCanada
- Department of Cellular and Molecular MedicineUniversity of OttawaOttawaOntarioCanada
- Centre for Neuromuscular DiseaseUniversity of OttawaOttawaOntarioCanada
| | - Matthew Stinson
- Department of BiochemistryUniformed Services University of the Health Sciences, F. Edward Hebert School of MedicineBethesdaMarylandUSA
| | - Natalya Belous
- Department of Anatomy, Physiology, and GeneticsUniformed Services University of the Health Sciences, F. Edward Hebert School of MedicineBethesdaMarylandUSA
| | - Elizabeth M. Bergman
- Department of Anatomy, Physiology, and GeneticsUniformed Services University of the Health Sciences, F. Edward Hebert School of MedicineBethesdaMarylandUSA
| | - Fritz W. Lischka
- Department of Anatomy, Physiology, and GeneticsUniformed Services University of the Health Sciences, F. Edward Hebert School of MedicineBethesdaMarylandUSA
| | - Jeremy Rotty
- Department of BiochemistryUniformed Services University of the Health Sciences, F. Edward Hebert School of MedicineBethesdaMarylandUSA
| | - Clifton L. Dalgard
- Department of Anatomy, Physiology, and GeneticsUniformed Services University of the Health Sciences, F. Edward Hebert School of MedicineBethesdaMarylandUSA
- The American Genome CenterUniformed Services University of the Health SciencesBethesdaMarylandUSA
| | - Rashmi Kothary
- Regenerative Medicine ProgramOttawa Hospital Research InstituteOttawaOntarioCanada
- Department of Cellular and Molecular MedicineUniversity of OttawaOttawaOntarioCanada
- Centre for Neuromuscular DiseaseUniversity of OttawaOttawaOntarioCanada
- Department of MedicineUniversity of OttawaOttawaOntarioCanada
| | | | - Barrington G. Burnett
- Department of Anatomy, Physiology, and GeneticsUniformed Services University of the Health Sciences, F. Edward Hebert School of MedicineBethesdaMarylandUSA
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Ganassi M, Zammit PS. Involvement of muscle satellite cell dysfunction in neuromuscular disorders: Expanding the portfolio of satellite cell-opathies. Eur J Transl Myol 2022; 32:10064. [PMID: 35302338 PMCID: PMC8992676 DOI: 10.4081/ejtm.2022.10064] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 02/11/2022] [Indexed: 12/03/2022] Open
Abstract
Neuromuscular disorders are a heterogeneous group of acquired or hereditary conditions that affect striated muscle function. The resulting decrease in muscle strength and motility irreversibly impacts quality of life. In addition to directly affecting skeletal muscle, pathogenesis can also arise from dysfunctional crosstalk between nerves and muscles, and may include cardiac impairment. Muscular weakness is often progressive and paralleled by continuous decline in the ability of skeletal muscle to functionally adapt and regenerate. Normally, the skeletal muscle resident stem cells, named satellite cells, ensure tissue homeostasis by providing myoblasts for growth, maintenance, repair and regeneration. We recently defined 'Satellite Cell-opathies' as those inherited neuromuscular conditions presenting satellite cell dysfunction in muscular dystrophies and myopathies (doi:10.1016/j.yexcr.2021.112906). Here, we expand the portfolio of Satellite Cell-opathies by evaluating the potential impairment of satellite cell function across all 16 categories of neuromuscular disorders, including those with mainly neurogenic and cardiac involvement. We explore the expression dynamics of myopathogenes, genes whose mutation leads to skeletal muscle pathogenesis, using transcriptomic analysis. This revealed that 45% of myopathogenes are differentially expressed during early satellite cell activation (0 - 5 hours). Of these 271 myopathogenes, 83 respond to Pax7, a master regulator of satellite cells. Our analysis suggests possible perturbation of satellite cell function in many neuromuscular disorders across all categories, including those where skeletal muscle pathology is not predominant. This characterisation further aids understanding of pathomechanisms and informs on development of prognostic and diagnostic tools, and ultimately, new therapeutics.
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Affiliation(s)
- Massimo Ganassi
- King's College London, Randall Centre for Cell and Molecular Biophysics, Guy's Campus, London.
| | - Peter S Zammit
- King's College London, Randall Centre for Cell and Molecular Biophysics, Guy's Campus, London.
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9
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Jablonka S, Hennlein L, Sendtner M. Therapy development for spinal muscular atrophy: perspectives for muscular dystrophies and neurodegenerative disorders. Neurol Res Pract 2022; 4:2. [PMID: 34983696 PMCID: PMC8725368 DOI: 10.1186/s42466-021-00162-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 10/21/2021] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Major efforts have been made in the last decade to develop and improve therapies for proximal spinal muscular atrophy (SMA). The introduction of Nusinersen/Spinraza™ as an antisense oligonucleotide therapy, Onasemnogene abeparvovec/Zolgensma™ as an AAV9-based gene therapy and Risdiplam/Evrysdi™ as a small molecule modifier of pre-mRNA splicing have set new standards for interference with neurodegeneration. MAIN BODY Therapies for SMA are designed to interfere with the cellular basis of the disease by modifying pre-mRNA splicing and enhancing expression of the Survival Motor Neuron (SMN) protein, which is only expressed at low levels in this disorder. The corresponding strategies also can be applied to other disease mechanisms caused by loss of function or toxic gain of function mutations. The development of therapies for SMA was based on the use of cell culture systems and mouse models, as well as innovative clinical trials that included readouts that had originally been introduced and optimized in preclinical studies. This is summarized in the first part of this review. The second part discusses current developments and perspectives for amyotrophic lateral sclerosis, muscular dystrophies, Parkinson's and Alzheimer's disease, as well as the obstacles that need to be overcome to introduce RNA-based therapies and gene therapies for these disorders. CONCLUSION RNA-based therapies offer chances for therapy development of complex neurodegenerative disorders such as amyotrophic lateral sclerosis, muscular dystrophies, Parkinson's and Alzheimer's disease. The experiences made with these new drugs for SMA, and also the experiences in AAV gene therapies could help to broaden the spectrum of current approaches to interfere with pathophysiological mechanisms in neurodegeneration.
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Affiliation(s)
- Sibylle Jablonka
- Institute of Clinical Neurobiology, University Hospital of Wuerzburg, Versbacher Str. 5, 97078, Wuerzburg, Germany.
| | - Luisa Hennlein
- Institute of Clinical Neurobiology, University Hospital of Wuerzburg, Versbacher Str. 5, 97078, Wuerzburg, Germany
| | - Michael Sendtner
- Institute of Clinical Neurobiology, University Hospital of Wuerzburg, Versbacher Str. 5, 97078, Wuerzburg, Germany.
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10
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Dumas SA, Villalón E, Bergman EM, Wilson KJ, Marugan JJ, Lorson CL, Burnett BG. OUP accepted manuscript. Hum Mol Genet 2022; 31:2989-3000. [PMID: 35419606 PMCID: PMC9433732 DOI: 10.1093/hmg/ddac068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 02/01/2022] [Accepted: 03/18/2022] [Indexed: 11/14/2022] Open
Abstract
Spinal muscular atrophy (SMA) is a neurodegenerative disease caused by reduced expression of the survival motor neuron (SMN) protein. Current disease-modifying therapies increase SMN levels and dramatically improve survival and motor function of SMA patients. Nevertheless, current treatments are not cures and autopsy data suggest that SMN induction is variable. Our group and others have shown that combinatorial approaches that target different modalities can improve outcomes in rodent models of SMA. Here we explore if slowing SMN protein degradation and correcting SMN splicing defects could synergistically increase SMN production and improve the SMA phenotype in model mice. We show that co-administering ML372, which inhibits SMN ubiquitination, with an SMN-modifying antisense oligonucleotide (ASO) increases SMN production in SMA cells and model mice. In addition, we observed improved spinal cord, neuromuscular junction and muscle pathology when ML372 and the ASO were administered in combination. Importantly, the combinatorial approach resulted in increased motor function and extended survival of SMA mice. Our results demonstrate that a combination of treatment modalities synergistically increases SMN levels and improves pathophysiology of SMA model mice over individual treatment.
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Affiliation(s)
| | | | - Elizabeth M Bergman
- Department of Anatomy, Physiology, and Genetics, Uniformed Services University of the Health Sciences, F. Edward Herbert School of Medicine, Bethesda, MD 20814, USA
| | - Kenneth J Wilson
- NIH Chemical Genomics Center, Discovery Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD 20892-2152, USA
| | - Juan J Marugan
- NIH Chemical Genomics Center, Discovery Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD 20892-2152, USA
| | - Christian L Lorson
- To whom correspondence should be addressed at: Barrington G. Burnett. Tel: +1 301-295-3506; ; Christian L. Lorson. Tel: +1 573-884-2219;
| | - Barrington G Burnett
- To whom correspondence should be addressed at: Barrington G. Burnett. Tel: +1 301-295-3506; ; Christian L. Lorson. Tel: +1 573-884-2219;
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Sansone VA. Risdiplam: new opportunities but more to be done. Lancet Neurol 2021; 21:23-24. [PMID: 34942130 DOI: 10.1016/s1474-4422(21)00428-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 11/13/2021] [Accepted: 11/23/2021] [Indexed: 11/26/2022]
Affiliation(s)
- Valeria A Sansone
- Neurorehabilitation Unit, University of Milan, Milan, Italy; NEMO Clinical Center, Milan 20162, Italy.
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McCormack NM, Villalón E, Viollet C, Soltis AR, Dalgard CL, Lorson CL, Burnett BG. Survival motor neuron deficiency slows myoblast fusion through reduced myomaker and myomixer expression. J Cachexia Sarcopenia Muscle 2021; 12:1098-1116. [PMID: 34115448 PMCID: PMC8350220 DOI: 10.1002/jcsm.12740] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 05/05/2021] [Accepted: 05/21/2021] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Spinal muscular atrophy is an inherited neurodegenerative disease caused by insufficient levels of the survival motor neuron (SMN) protein. Recently approved treatments aimed at increasing SMN protein levels have dramatically improved patient survival and have altered the disease landscape. While restoring SMN levels slows motor neuron loss, many patients continue to have smaller muscles and do not achieve normal motor milestones. While timing of treatment is important, it remains unclear why SMN restoration is insufficient to fully restore muscle size and function. We and others have shown that SMN-deficient muscle precursor cells fail to efficiently fuse into myotubes. However, the role of SMN in myoblast fusion is not known. METHODS In this study, we show that SMN-deficient myoblasts readily fuse with wild-type myoblasts, demonstrating fusion competency. Conditioned media from wild type differentiating myoblasts do not rescue the fusion deficit of SMN-deficient cells, suggesting that compromised fusion may primarily be a result of altered membrane dynamics at the cell surface. Transcriptome profiling of skeletal muscle from SMN-deficient mice revealed altered expression of cell surface fusion molecules. Finally, using cell and mouse models, we investigate if myoblast fusion can be rescued in SMN-deficient myoblast and improve the muscle pathology in SMA mice. RESULTS We found reduced expression of the muscle fusion proteins myomaker (P = 0.0060) and myomixer (P = 0.0051) in the muscle of SMA mice. Suppressing SMN expression in C2C12 myoblast cells reduces expression of myomaker (35% reduction; P < 0.0001) and myomixer, also known as myomerger and minion, (30% reduction; P < 0.0001) and restoring SMN levels only partially restores myomaker and myomixer expression. Ectopic expression of myomixer improves myofibre number (55% increase; P = 0.0006) and motor function (35% decrease in righting time; P = 0.0089) in SMA model mice and enhances motor function (82% decrease in righting time; P < 0.0001) and extends survival (28% increase; P < 0.01) when administered in combination with an antisense oligonucleotide that increases SMN protein levels. CONCLUSIONS Here, we identified reduced expression of muscle fusion proteins as a key factor in the fusion deficits of SMN-deficient myoblasts. This discovery provides a novel target to improve SMA muscle pathology and motor function, which in combination with SMN increasing therapy could enhance clinical outcomes for SMA patients.
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Affiliation(s)
- Nikki M McCormack
- Department of Anatomy, Physiology, and Genetics, Uniformed Services University of the Health Sciences, F. Edward Hébert School of Medicine, Bethesda, MD, USA
| | - Eric Villalón
- Bond Life Sciences Center, University of Missouri, Columbia, MO, USA.,Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO, USA
| | - Coralie Viollet
- Collaborative Health Initiative Research Program, Uniformed Services University of the Heath Sciences, Bethesda, MD, USA
| | - Anthony R Soltis
- Collaborative Health Initiative Research Program, Uniformed Services University of the Heath Sciences, Bethesda, MD, USA.,Henry M. Jackson Foundation, Bethesda, MD, USA
| | - Clifton L Dalgard
- Department of Anatomy, Physiology, and Genetics, Uniformed Services University of the Health Sciences, F. Edward Hébert School of Medicine, Bethesda, MD, USA.,Collaborative Health Initiative Research Program, Uniformed Services University of the Heath Sciences, Bethesda, MD, USA.,The American Genome Center, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Christian L Lorson
- Bond Life Sciences Center, University of Missouri, Columbia, MO, USA.,Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO, USA
| | - Barrington G Burnett
- Department of Anatomy, Physiology, and Genetics, Uniformed Services University of the Health Sciences, F. Edward Hébert School of Medicine, Bethesda, MD, USA
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