1
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Huang W, Cano JC, Fénelon K. Deciphering the role of brainstem glycinergic neurons during startle and prepulse inhibition. Brain Res 2024; 1836:148938. [PMID: 38615924 DOI: 10.1016/j.brainres.2024.148938] [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: 12/22/2023] [Revised: 03/29/2024] [Accepted: 04/11/2024] [Indexed: 04/16/2024]
Abstract
Prepulse inhibition (PPI) of the auditory startle response, a key measure of sensorimotor gating, diminishes with age and is impaired in various neurological conditions. While PPI deficits are often associated with cognitive impairments, their reversal is routinely used in experimental systems for antipsychotic drug screening. Yet, the cellular and circuit-level mechanisms of PPI remain unclear, even under non-pathological conditions. We recently showed that brainstem neurons located in the caudal pontine reticular nucleus (PnC) expressing the glycine transporter type 2 (GlyT2±) receive inputs from the central nucleus of the amygdala (CeA) and contribute to PPI but via an uncharted pathway. Here, using tract-tracing, immunohistochemistry and in vitro optogenetic manipulations coupled to field electrophysiological recordings, we reveal the neuroanatomical distribution of GlyT2± PnC neurons and PnC-projecting CeA glutamatergic neurons and we provide mechanistic insights on how these glutamatergic inputs suppress auditory neurotransmission in PnC sections. Additionally, in vivo experiments using GlyT2-Cre mice confirm that optogenetic activation of GlyT2± PnC neurons enhances PPI and is sufficient to induce PPI in young mice, emphasizing their role. However, in older mice, PPI decline is not further influenced by inhibiting GlyT2± neurons. This study highlights the importance of GlyT2± PnC neurons in PPI and underscores their diminished activity in age-related PPI decline.
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Affiliation(s)
- Wanyun Huang
- Biology Department, University of Massachusetts Amherst, Life Science Laboratories, 240 Thatcher Road, Amherst, MA, 01002, USA
| | - Jose C Cano
- Department of Biological Sciences, University of Texas at El Paso, 500 West University Avenue, El Paso, TX, 79912, USA
| | - Karine Fénelon
- Biology Department, University of Massachusetts Amherst, Life Science Laboratories, 240 Thatcher Road, Amherst, MA, 01002, USA.
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2
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Gao J, Sterling E, Hankin R, Sikal A, Yao Y. Therapeutics Targeting Skeletal Muscle in Amyotrophic Lateral Sclerosis. Biomolecules 2024; 14:878. [PMID: 39062592 PMCID: PMC11275039 DOI: 10.3390/biom14070878] [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: 05/21/2024] [Revised: 07/11/2024] [Accepted: 07/16/2024] [Indexed: 07/28/2024] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a complex neuromuscular disease characterized by progressive motor neuron degeneration, neuromuscular junction dismantling, and muscle wasting. The pathological and therapeutic studies of ALS have long been neurocentric. However, recent insights have highlighted the significance of peripheral tissue, particularly skeletal muscle, in disease pathology and treatment. This is evidenced by restricted ALS-like muscle atrophy, which can retrogradely induce neuromuscular junction and motor neuron degeneration. Moreover, therapeutics targeting skeletal muscles can effectively decelerate disease progression by modulating muscle satellite cells for muscle repair, suppressing inflammation, and promoting the recovery or regeneration of the neuromuscular junction. This review summarizes and discusses therapeutic strategies targeting skeletal muscles for ALS treatment. It aims to provide a comprehensive reference for the development of novel therapeutics targeting skeletal muscles, potentially ameliorating the progression of ALS.
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Affiliation(s)
| | | | | | | | - Yao Yao
- Regenerative Bioscience Center, Department of Animal and Dairy Science, College of Agricultural and Environmental Science, University of Georgia, Athens, GA 30602, USA (E.S.)
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3
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Wang Q, Cui C, Zhang N, Lin W, Chai S, Chow SKH, Wong RMY, Hu Y, Law SW, Cheung WH. Effects of physical exercise on neuromuscular junction degeneration during ageing: A systematic review. J Orthop Translat 2024; 46:91-102. [PMID: 38817243 PMCID: PMC11137388 DOI: 10.1016/j.jot.2024.03.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 03/27/2024] [Accepted: 03/31/2024] [Indexed: 06/01/2024] Open
Abstract
The neuromuscular junction (NMJ) is a specialized chemical synapse that converts neural impulses into muscle action. Age-associated NMJ degeneration, which involves nerve terminal and postsynaptic decline, denervation, and loss of motor units, significantly contributes to muscle weakness and dysfunction. Although physical training has been shown to make substantial modifications in NMJ of both young and aged animals, the results are often influenced by methodological variables in existing studies. Moreover, there is still lack of strong consensus on the specific effects of exercise on improving the morphology and function of the ageing NMJ. Consequently, the purpose of this study was to conduct a systematic review to elucidate the effects of exercise training on NMJ compartments in the elderly. We conducted a systematic review using PubMed, Embase, and Web of Science databases, employing relevant keywords. Two independent reviewers selected studies that detailed NMJ changes during exercise in ageing, written in English, and available in full text. In total, 20 papers were included. We examined the altered adaptation of the NMJ to exercise, focusing on presynaptic and postsynaptic structures and myofibers in older animals or humans. Our findings indicated that aged NMJs exhibited different adaptive responses to physical exercise compared to younger counterparts. Endurance training, compared with resistance and voluntary exercise regimens, was found to have a more pronounced effect on NMJ structural remodeling, particularly in fast twitch muscle fibers. Physical exercise was observed to promote the formation and maintenance of acetylcholine receptor (AChR) clusters by increasing the recombinant docking protein 7 (Dok7) expression and stabilizing Agrin and lipoprotein receptor-related protein 4 (LRP4). These insights suggest that research on exercise-related therapies could potentially attenuate the progression of neuromuscular degeneration. Translational potential of this article: This systematic review provides a detailed overview of the effects of different types of physical exercise on improving NMJ in the elderly, providing scientific support for the timely intervention of muscle degeneration in the elderly by physical exercise, and providing help for the development of new therapeutic interventions in the future.
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Affiliation(s)
- Qianjin Wang
- Musculoskeletal Research Laboratory, Department of Orthopaedics and Traumatology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
- Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
| | - Can Cui
- Musculoskeletal Research Laboratory, Department of Orthopaedics and Traumatology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
- Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
| | - Ning Zhang
- Musculoskeletal Research Laboratory, Department of Orthopaedics and Traumatology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
- Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
| | - Wujian Lin
- Musculoskeletal Research Laboratory, Department of Orthopaedics and Traumatology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
- Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
| | - Senlin Chai
- Musculoskeletal Research Laboratory, Department of Orthopaedics and Traumatology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
- Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
| | - Simon Kwoon-Ho Chow
- Musculoskeletal Research Laboratory, Department of Orthopaedics and Traumatology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
- Department of Orthopaedic Surgery, Stanford University, Stanford, CA, USA
| | - Ronald Man Yeung Wong
- Musculoskeletal Research Laboratory, Department of Orthopaedics and Traumatology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
| | - Yong Hu
- Department of Orthopaedics and Traumatology, The University of Hong Kong, Hong Kong Special Administrative Region of China
| | - Sheung Wai Law
- Musculoskeletal Research Laboratory, Department of Orthopaedics and Traumatology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
| | - Wing-Hoi Cheung
- Musculoskeletal Research Laboratory, Department of Orthopaedics and Traumatology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
- Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
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4
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Kim S, Jang S, Lee O. Single fiber curvature for muscle impairment assessment: Phase contrast imaging of stroke-induced animals. Microsc Res Tech 2024; 87:705-715. [PMID: 37983687 DOI: 10.1002/jemt.24459] [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: 05/28/2023] [Revised: 10/15/2023] [Accepted: 11/05/2023] [Indexed: 11/22/2023]
Abstract
There are technical challenges in imaging studies that can three-dimensionally (3D) analyze a single fiber (SF) to observe the functionality of the entire muscle after stroke. This study proposes a 3D assessment technique that only segments the SF of the right stroke-induced soleus muscle of a gerbil using synchrotron radiation x-ray microcomputed tomography (SR-μCT), which is capable of muscle structure analysis. Curvature damage in the SF of the left soleus muscle (impaired) progressed at 7-day intervals after the stroke in the control; particularly on the 7 days (1 week) and 14 days (2 weeks), as observed through visualization analysis. At 2 weeks, the SF volume was significantly reduced in the control impaired group (p = .033), and was significantly less than that in the non-impaired group (p = .009). We expect that animal post-stroke studies will improve the basic field of rehabilitation therapy by diagnosing the degree of SF curvature. RESEARCH HIGHLIGHTS: Muscle evaluation after ischemic stroke using synchrotron radiation x-ray microcomputed tomography (SR-μCT). Curvature is measured by segmenting a single fiber (SF) in the muscle. Structural changes in the SF of impaired gerbils at 7-day intervals were assessed.
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Affiliation(s)
- Subok Kim
- Department of Software Convergence, Graduate School, Soonchunhyang University, Asan, Republic of Korea
| | - Sanghun Jang
- Department of Physical Therapy, College of Health and Life Sciences, Korea National University of Transportation, Jeungpyeong-gun, Republic of Korea
| | - Onseok Lee
- Department of Software Convergence, Graduate School, Soonchunhyang University, Asan, Republic of Korea
- Department of Medical IT Engineering, College of Medical Sciences, Soonchunhyang University, Asan, Republic of Korea
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5
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Eguchi T, Tezuka T, Watanabe Y, Inoue-Yamauchi A, Sagara H, Ozawa M, Yamanashi Y. Calcium-binding protein 7 expressed in muscle negatively regulates age-related degeneration of neuromuscular junctions in mice. iScience 2024; 27:108997. [PMID: 38327785 PMCID: PMC10847746 DOI: 10.1016/j.isci.2024.108997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 12/05/2023] [Accepted: 01/19/2024] [Indexed: 02/09/2024] Open
Abstract
The neuromuscular junction (NMJ) forms centrally in myotubes and, as the only synapse between motor neuron and myotube, are indispensable for motor activity. The midmuscle formation of NMJs, including midmuscle-restricted expression of NMJ-related genes, is governed by the muscle-specific kinase (MuSK). However, mechanisms underlying MuSK-mediated signaling are unclear. Here, we find that the Calcium-binding protein 7 (Cabp7) gene shows midmuscle-restricted expression, and muscle-specific depletion of Cabp7 in mice accelerated age-related NMJ degeneration, muscle weakness/atrophy, and motor dysfunction. Surprisingly, forced expression in muscle of CIP, an inhibitory peptide of the negative regulator of NMJ formation cyclin-dependent kinase 5 (Cdk5), restored NMJ integrity and muscle strength, and healed muscle atrophy in muscle-specific Cabp7-deficient mice, which showed increased muscle expression of the Cdk5 activator p25. These findings together demonstrate that MuSK-mediated signaling induces muscle expression of Cabp7, which suppresses age-related NMJ degeneration likely by attenuating p25 expression, providing insights into prophylactic/therapeutic intervention against age-related motor dysfunction.
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Affiliation(s)
- Takahiro Eguchi
- Division of Genetics, The Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan
| | - Tohru Tezuka
- Division of Genetics, The Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan
| | - Yuji Watanabe
- Medical Proteomics Laboratory, The Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan
| | - Akane Inoue-Yamauchi
- Division of Genetics, The Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan
| | - Hiroshi Sagara
- Medical Proteomics Laboratory, The Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan
| | - Manabu Ozawa
- Laboratory of Reproductive Systems Biology, The Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan
- Core Laboratory for Developing Advanced Animal Models, The Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan
| | - Yuji Yamanashi
- Division of Genetics, The Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan
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6
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Cossins J, Kozma I, Canzonetta C, Hawkins A, Beeson D, Sepulveda P, Dong Y. Dose escalation pre-clinical trial of novel DOK7-AAV in mouse model of DOK7 congenital myasthenia. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.09.579626. [PMID: 38405691 PMCID: PMC10888934 DOI: 10.1101/2024.02.09.579626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
Congenital myasthenic syndromes (CMS) are a group of inherited disorders characterised by defective neuromuscular transmission and fatigable muscle weakness. Mutations in DOK7 , a gene encoding a post-synaptic protein crucial in the formation and stabilisation of the neuromuscular junction (NMJ), rank among the leading three prevalent causes of CMS in diverse populations globally. The majority of DOK7 CMS patients experience varying degrees of disability despite receiving optimised treatment, necessitating the development of improved therapeutic approaches. Here we executed a dose escalation pre-clinical trial using a DOK7-CMS mouse model to assess the efficacy of Amp-101, an innovative AAV gene replacement therapy. Amp-101 is based on AAVrh74 and contains human DOK7 cDNA under the control of a muscle-restricted promoter. We show that at doses 6x10 13 vg/kg and 1x10 14 vg/kg, Amp-101 generated enlarged NMJs and rescued the very severe phenotype of the model. Treated mice became at least as strong as WT littermates and the diaphragm and tibialis anterior muscles displayed robust expression of DOK7. This data suggests that Amp-101 is a promising candidate to move forward to clinic trials.
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7
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Sugimoto T, Sakamaki C, Kimura T, Eguchi T, Miura S, Kamei Y. Peroxisome proliferator-activated receptor γ coactivator 1α regulates downstream of tyrosine kinase-7 (Dok-7) expression important for neuromuscular junction formation. Sci Rep 2024; 14:1780. [PMID: 38245592 PMCID: PMC10799880 DOI: 10.1038/s41598-024-52198-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Accepted: 01/15/2024] [Indexed: 01/22/2024] Open
Abstract
The neuromuscular junction (NMJ)-formed between a motor nerve terminal and skeletal muscle fiber-plays an important role in muscle contraction and other muscle functions. Aging and neurodegeneration worsen NMJ formation and impair muscle function. Downstream of tyrosine kinase-7 (Dok-7), expressed in skeletal muscle fibers, is essential for the formation of NMJ. Exercise increases the expression of the transcriptional coactivator peroxisome proliferator-activated receptor γ coactivator 1α (PGC1α) in skeletal muscles and restores NMJ formation. In this study, we used skeletal muscle-specific PGC1α knockout or overexpression mice to examine the role of PGC1α in regulating Dok-7 expression and NMJ formation. Our findings revealed that Dok-7 expression is regulated by PGC1α, and luciferase activity of the Dok-7 promoter is greatly increased by coexpressing PGC1α and estrogen receptor-related receptor α. Thus, we suggest PGC1α is involved in exercise-mediated restoration of NMJ formation.
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Affiliation(s)
- Takumi Sugimoto
- Laboratory of Molecular Nutrition, Graduate School of Environmental and Life Science, Kyoto Prefectural University, Kyoto, Japan
| | - Chihiro Sakamaki
- Laboratory of Molecular Nutrition, Graduate School of Environmental and Life Science, Kyoto Prefectural University, Kyoto, Japan
| | - Tokushi Kimura
- Laboratory of Molecular Nutrition, Graduate School of Environmental and Life Science, Kyoto Prefectural University, Kyoto, Japan
| | - Takahiro Eguchi
- Brain-Skeletal Muscle Connection in Aging Project Team, Geroscience Research Center, National Center for Geriatrics and Gerontology, Aichi, Japan
| | - Shinji Miura
- Laboratory of Nutritional Biochemistry, Graduate School of Nutritional and Environmental Sciences, University of Shizuoka, Shizuoka, Japan
| | - Yasutomi Kamei
- Laboratory of Molecular Nutrition, Graduate School of Environmental and Life Science, Kyoto Prefectural University, Kyoto, Japan.
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8
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Qaisar R. Targeting neuromuscular junction to treat neuromuscular disorders. Life Sci 2023; 333:122186. [PMID: 37858716 DOI: 10.1016/j.lfs.2023.122186] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Revised: 10/07/2023] [Accepted: 10/16/2023] [Indexed: 10/21/2023]
Abstract
The integrity and preservation of the neuromuscular junction (NMJ), the interface between the motor neuron and skeletal muscle, is critical for maintaining a healthy skeletal muscle. The structural and/or functional defects in the three cellular components of NMJ, namely the pre-synaptic terminal, synaptic cleft, and post-synaptic region, negatively affect skeletal muscle mass and/or strength. Therefore, NMJ repair appears to be an appropriate therapy for muscle disorders. Mouse models provide a detailed molecular characterization of various cellular components of NMJ with relevance to human diseases. This review discusses different molecular targets on the three cellular components of NMJ for treating muscle diseases. The potential effects of these therapies on NMJ morphology and motor performance, their therapeutic efficacy, and clinical relevance are discussed. Collectively, the available data supports targeting NMJ alone or as an adjunct therapy in treating muscle disorders. However, the potential impact of such interventions on human patients with muscle disorders requires further investigation.
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Affiliation(s)
- Rizwan Qaisar
- Basic Medical Sciences, College of Medicine, University of Sharjah, Sharjah, United Arab Emirates; Space Medicine Research Group, Sharjah Institute for Medical and Health Sciences, University of Sharjah, Sharjah 27272, United Arab Emirates; Cardiovascular Research Group, Sharjah Institute for Medical and Health Sciences, University of Sharjah, Sharjah 27272, United Arab Emirates.
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9
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Huang YT, Crick HR, Chaytow H, van der Hoorn D, Alhindi A, Jones RA, Hector RD, Cobb SR, Gillingwater TH. Long-term muscle-specific overexpression of DOK7 in mice using AAV9-tMCK-DOK7. MOLECULAR THERAPY. NUCLEIC ACIDS 2023; 33:617-628. [PMID: 37637210 PMCID: PMC10457688 DOI: 10.1016/j.omtn.2023.07.036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 07/31/2023] [Indexed: 08/29/2023]
Abstract
Neuromuscular junction (NMJ) dysfunction underlies several diseases, including congenital myasthenic syndromes (CMSs) and motor neuron disease (MND). Molecular pathways governing NMJ stability are therefore of interest from both biological and therapeutic perspectives. Muscle-specific kinase (MuSK) is necessary for the formation and maintenance of post-synaptic elements of the NMJ, and downstream of tyrosine kinases 7 (DOK7) is crucial for activation of the MuSK pathway. Overexpression of DOK7 using AAV9 has been shown to ameliorate neuromuscular pathology in pre-clinical disease models of CMS and MND. However, long-term consequences of DOK7 expression have been sparsely investigated and targeted overexpression of DOK7 in skeletal muscle yet to be established. Here, we developed and characterized a novel AAV9-DOK7 facilitating forced expression of DOK7 under a skeletal muscle-specific promoter. AAV9-tMCK-DOK7 was systemically delivered to newborn mice that were monitored over 6 months. DOK7 overexpression was restricted to skeletal muscles. Body weight, blood biochemistry, and histopathological assessments were unaffected by AAV9-tMCK-DOK7 treatment. In contrast, forced expression of DOK7 resulted in enlargement of both the pre- and post-synaptic components of the NMJ, without causing denervation. We conclude that muscle-specific DOK7 overexpression can be achieved in a safe manner, with the capacity to target NMJs in vivo.
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Affiliation(s)
- Yu-Ting Huang
- Edinburgh Medical School: Biomedical Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK
- Euan MacDonald Centre for Motor Neuron Disease Research, Edinburgh EH16 4SB, UK
| | - Hannah R. Crick
- Edinburgh Medical School: Biomedical Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK
- Euan MacDonald Centre for Motor Neuron Disease Research, Edinburgh EH16 4SB, UK
| | - Helena Chaytow
- Edinburgh Medical School: Biomedical Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK
- Euan MacDonald Centre for Motor Neuron Disease Research, Edinburgh EH16 4SB, UK
| | - Dinja van der Hoorn
- Edinburgh Medical School: Biomedical Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK
- Euan MacDonald Centre for Motor Neuron Disease Research, Edinburgh EH16 4SB, UK
| | - Abrar Alhindi
- Edinburgh Medical School: Biomedical Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK
- Euan MacDonald Centre for Motor Neuron Disease Research, Edinburgh EH16 4SB, UK
- Faculty of Medicine, Department of Anatomy, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Ross A. Jones
- Edinburgh Medical School: Biomedical Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK
- Euan MacDonald Centre for Motor Neuron Disease Research, Edinburgh EH16 4SB, UK
| | | | | | - Thomas H. Gillingwater
- Edinburgh Medical School: Biomedical Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK
- Euan MacDonald Centre for Motor Neuron Disease Research, Edinburgh EH16 4SB, UK
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10
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Saito A, Matsui S, Chino A, Sato S, Takeshita N. Discovery and pharmacological characterization of novel positive allosteric modulators acting on skeletal muscle-type nicotinic acetylcholine receptors. Biochem Biophys Res Commun 2023; 668:27-34. [PMID: 37235916 DOI: 10.1016/j.bbrc.2023.04.103] [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: 04/11/2023] [Revised: 04/21/2023] [Accepted: 04/27/2023] [Indexed: 05/28/2023]
Abstract
Skeletal muscle-type nicotinic acetylcholine receptors (m-nAChRs) are ligand-gated ion channels that open after activation by ACh and whose signals cause muscle contraction. Defects in neurotransmission are reported in disorders such as myasthenia gravis (MG) and congenital myasthenia syndromes (CMS). Although treatments for these disorders exist, therapies which significantly increase muscle strength have yet to be reported. Positive allosteric modulators (PAMs), which promote ACh signaling through AChRs, are expected to be promising therapeutic agents. In this study, we identified an m-nAChR PAM called AS3513678 by high-throughput screening using human myotube cells and modified it to obtain novel compounds (AS3566987 and AS3580239) that showed even stronger PAM activity. AS3580239 caused a leftward shift in the ACh concentration-response curve and was 14.0-fold potent at 10 μM compared with vehicle. Next, we examined the effect of AS3580239 on electrically-induced isometric contraction of the extensor digitorum longus (EDL) muscle in wild-type (WT) and MG model rats. AS3580239 enhanced EDL muscle contraction in both WT and MG model rats at 30 μM. These data suggest that AS3580239 improved neurotransmission and enhanced muscle strength. Thus, m-nAChR PAMs may be a useful treatment for neuromuscular diseases.
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Affiliation(s)
- Asako Saito
- Astellas Pharma Inc, 21, Miyukigaoka, Tsukuba, Ibaraki, 305-8585, Japan.
| | - Shigeo Matsui
- Astellas Pharma Inc, 21, Miyukigaoka, Tsukuba, Ibaraki, 305-8585, Japan
| | - Ayaka Chino
- Astellas Pharma Inc, 21, Miyukigaoka, Tsukuba, Ibaraki, 305-8585, Japan
| | - Shota Sato
- Astellas Pharma Inc, 21, Miyukigaoka, Tsukuba, Ibaraki, 305-8585, Japan
| | - Nobuaki Takeshita
- Astellas Pharma Inc, 21, Miyukigaoka, Tsukuba, Ibaraki, 305-8585, Japan
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11
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Li D, Johmura Y, Morimoto S, Doi M, Nakanishi K, Ozawa M, Tsunekawa Y, Inoue-Yamauchi A, Naruse H, Matsukawa T, Takeshita Y, Suzuki N, Aoki M, Nishiyama A, Zeng X, Konishi C, Suzuki N, Nishiyama A, Harris AS, Morita M, Yamaguchi K, Furukawa Y, Nakai K, Tsuji S, Yamazaki S, Yamanashi Y, Shimada S, Okada T, Okano H, Toda T, Nakanishi M. LONRF2 is a protein quality control ubiquitin ligase whose deficiency causes late-onset neurological deficits. NATURE AGING 2023; 3:1001-1019. [PMID: 37474791 DOI: 10.1038/s43587-023-00464-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 06/29/2023] [Indexed: 07/22/2023]
Abstract
Protein misfolding is a major factor of neurodegenerative diseases. Post-mitotic neurons are highly susceptible to protein aggregates that are not diluted by mitosis. Therefore, post-mitotic cells may have a specific protein quality control system. Here, we show that LONRF2 is a bona fide protein quality control ubiquitin ligase induced in post-mitotic senescent cells. Under unperturbed conditions, LONRF2 is predominantly expressed in neurons. LONRF2 binds and ubiquitylates abnormally structured TDP-43 and hnRNP M1 and artificially misfolded proteins. Lonrf2-/- mice exhibit age-dependent TDP-43-mediated motor neuron (MN) degeneration and cerebellar ataxia. Mouse induced pluripotent stem cell-derived MNs lacking LONRF2 showed reduced survival, shortening of neurites and accumulation of pTDP-43 and G3BP1 after long-term culture. The shortening of neurites in MNs from patients with amyotrophic lateral sclerosis is rescued by ectopic expression of LONRF2. Our findings reveal that LONRF2 is a protein quality control ligase whose loss may contribute to MN degeneration and motor deficits.
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Affiliation(s)
- Dan Li
- Division of Cancer Cell Biology, The University of Tokyo, Tokyo, Japan
| | - Yoshikazu Johmura
- Division of Cancer Cell Biology, The University of Tokyo, Tokyo, Japan.
- Division of Cancer and Senescence Biology, Cancer Research Institute, Institute for Frontier Science Initiative, Kanazawa University, Kanazawa, Japan.
| | - Satoru Morimoto
- Department of Physiology, Keio University School of Medicine, Tokyo, Japan
| | - Miyuki Doi
- Department of Neuroscience and Cell Biology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Keiko Nakanishi
- Department of Pediatrics, Central Hospital, and Department of Disease Model, Institute for Developmental Research, Aichi Developmental Disability Center, Kasugai, Japan
| | - Manabu Ozawa
- Laboratory of Reproductive Systems Biology, The University of Tokyo, Tokyo, Japan
| | - Yuji Tsunekawa
- Division of Molecular and Medical Genetics, Center for Gene and Cell Therapy, The University of Tokyo, Tokyo, Japan
| | | | - Hiroya Naruse
- Department of Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Takashi Matsukawa
- Department of Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Yukio Takeshita
- Department of Neurology and Clinical Neuroscience, Yamaguchi University Graduate School of Medicine, Yamaguchi, Japan
| | - Naoki Suzuki
- Department of Neurology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Masashi Aoki
- Department of Neurology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Ayumi Nishiyama
- Department of Neurology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Xin Zeng
- Laboratory of Functional Analysis in silico, Human Genome Center, The University of Tokyo, Tokyo, Japan
| | - Chieko Konishi
- Division of Cancer Cell Biology, The University of Tokyo, Tokyo, Japan
| | - Narumi Suzuki
- Division of Cancer Cell Biology, The University of Tokyo, Tokyo, Japan
| | - Atsuya Nishiyama
- Division of Cancer Cell Biology, The University of Tokyo, Tokyo, Japan
| | | | - Mariko Morita
- Division of Clinical Genome Research, The University of Tokyo, Tokyo, Japan
| | - Kiyoshi Yamaguchi
- Division of Clinical Genome Research, The University of Tokyo, Tokyo, Japan
| | - Yoichi Furukawa
- Division of Clinical Genome Research, The University of Tokyo, Tokyo, Japan
| | - Kenta Nakai
- Laboratory of Functional Analysis in silico, Human Genome Center, The University of Tokyo, Tokyo, Japan
| | - Shoji Tsuji
- Department of Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Satoshi Yamazaki
- Division of Stem Cell Biology, Center for Stem Cell Biology and Regenerative Medicine, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan
- Laboratory of Stem Cell Therapy, Faculty of Medicine, University of Tsukuba, Ibaraki, Japan
| | - Yuji Yamanashi
- Division of Genetics, The University of Tokyo, Tokyo, Japan
| | - Shoichi Shimada
- Department of Neuroscience and Cell Biology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Takashi Okada
- Division of Molecular and Medical Genetics, Center for Gene and Cell Therapy, The University of Tokyo, Tokyo, Japan
| | - Hideyuki Okano
- Department of Physiology, Keio University School of Medicine, Tokyo, Japan
| | - Tatsushi Toda
- Department of Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Makoto Nakanishi
- Division of Cancer Cell Biology, The University of Tokyo, Tokyo, Japan.
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12
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Hu Z, Luo Y, Liu Y, Luo Y, Wang L, Gou S, Peng Y, Wei R, Jia D, Wang Y, Gao S, Zhang Y. Partial inhibition of class III PI3K VPS-34 ameliorates motor aging and prolongs health span. PLoS Biol 2023; 21:e3002165. [PMID: 37432924 DOI: 10.1371/journal.pbio.3002165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Accepted: 05/13/2023] [Indexed: 07/13/2023] Open
Abstract
Global increase of life expectancy is rarely accompanied by increased health span, calling for a greater understanding of age-associated behavioral decline. Motor independence is strongly associated with the quality of life of elderly people, yet the regulators for motor aging have not been systematically explored. Here, we designed a fast and efficient genome-wide screening assay in Caenorhabditis elegans and identified 34 consistent genes as potential regulators of motor aging. Among the top hits, we found VPS-34, the class III phosphatidylinositol 3-kinase that phosphorylates phosphatidylinositol (PI) to phosphatidylinositol 3-phosphate (PI(3)P), regulates motor function in aged but not young worms. It primarily functions in aged motor neurons by inhibiting PI(3)P-PI-PI(4)P conversion to reduce neurotransmission at the neuromuscular junction (NMJ). Genetic and pharmacological inhibition of VPS-34 improve neurotransmission and muscle integrity, ameliorating motor aging in both worms and mice. Thus, our genome-wide screening revealed an evolutionarily conserved, actionable target to delay motor aging and prolong health span.
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Affiliation(s)
- Zhongliang Hu
- National Clinical Research Center for Geriatrics, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Yamei Luo
- National Clinical Research Center for Geriatrics, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Yuting Liu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Yaru Luo
- National Clinical Research Center for Geriatrics, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Liangce Wang
- National Clinical Research Center for Geriatrics, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Shengsong Gou
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Pediatrics, State Key Laboratory of Biotherapy, West China Second University Hospital, Sichuan University, Chengdu, China
| | - Yuling Peng
- National Clinical Research Center for Geriatrics, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Rui Wei
- National Clinical Research Center for Geriatrics, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Da Jia
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Pediatrics, State Key Laboratory of Biotherapy, West China Second University Hospital, Sichuan University, Chengdu, China
| | - Yuan Wang
- National Clinical Research Center for Geriatrics, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Shangbang Gao
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Yan Zhang
- National Clinical Research Center for Geriatrics, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan, China
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13
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Mori S, Suzuki S, Konishi T, Kawaguchi N, Kishi M, Kuwabara S, Ishizuchi K, Zhou H, Shibasaki F, Tsumoto H, Omura T, Miura Y, Mori S, Higashihara M, Murayama S, Shigemoto K. Proteolytic ectodomain shedding of muscle-specific tyrosine kinase in myasthenia gravis. Exp Neurol 2023; 361:114300. [PMID: 36525997 DOI: 10.1016/j.expneurol.2022.114300] [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: 07/12/2022] [Revised: 11/07/2022] [Accepted: 12/10/2022] [Indexed: 12/15/2022]
Abstract
Autoantibodies to muscle-specific tyrosine kinase (MuSK) proteins at the neuromuscular junction (NMJ) cause refractory generalized myasthenia gravis (MG) with dyspnea more frequently than other MG subtypes. However, the mechanisms via which MuSK, a membrane protein locally expressed on the NMJ of skeletal muscle, is supplied to the immune system as an autoantigen remains unknown. Here, we identified MuSK in both mouse and human serum, with the amount of MuSK dramatically increasing in mice with motor nerve denervation and in MG model mice. Peptide analysis by liquid chromatography-tandem-mass spectrometry (LC-MS/MS) confirmed the presence of MuSK in both human and mouse serum. Furthermore, some patients with MG have significantly higher amounts of MuSK in serum than healthy controls. Our results indicated that the secretion of MuSK proteins from muscles into the bloodstream was induced by ectodomain shedding triggered by neuromuscular junction failure. The results may explain why MuSK-MG is refractory to treatments and causes rapid muscle atrophy in some patients due to the denervation associated with Ab-induced disruption of neuromuscular transmission at the NMJ. Such discoveries pave the way for new MG treatments, and MuSK may be used as a biomarker for other neuromuscular diseases in preclinical studies, clinical diagnostics, therapeutics, and drug discovery.
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Affiliation(s)
- Shuuichi Mori
- Research Team for Geriatric Medicine, Tokyo Metropolitan Institute of Gerontology (TMIG), Tokyo, Japan
| | - Shigeaki Suzuki
- Department of Neurology, Keio University School of Medicine, Tokyo, Japan
| | | | - Naoki Kawaguchi
- Dowa Institute of Clinical Neuroscience, Neurology Clinic Chiba, Chiba, Japan
| | - Masahiko Kishi
- Department of Internal Medicine, Toho University Sakura Medical Center, Chiba, Japan
| | - Satoshi Kuwabara
- Department of Neurology, Chiba University School of Medicine, Chiba, Japan
| | - Kei Ishizuchi
- Department of Neurology, Keio University School of Medicine, Tokyo, Japan
| | - Heying Zhou
- Research Team for Geriatric Medicine, Tokyo Metropolitan Institute of Gerontology (TMIG), Tokyo, Japan
| | - Futoshi Shibasaki
- Department of Genome Medicine, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Hiroki Tsumoto
- Research Team for Mechanism of Aging, TMIG, Tokyo, Japan
| | - Takuya Omura
- Research Team for Geriatric Medicine, Tokyo Metropolitan Institute of Gerontology (TMIG), Tokyo, Japan
| | - Yuri Miura
- Research Team for Mechanism of Aging, TMIG, Tokyo, Japan
| | - Seijiro Mori
- Research Team for Geriatric Medicine, Tokyo Metropolitan Institute of Gerontology (TMIG), Tokyo, Japan
| | - Mana Higashihara
- Department of Neurology, Tokyo Metropolitan Geriatric Hospital, Tokyo (TMGHIG), Japan
| | | | - Kazuhiro Shigemoto
- Research Team for Geriatric Medicine, Tokyo Metropolitan Institute of Gerontology (TMIG), Tokyo, Japan.
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14
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DOK7 Promotes NMJ Regeneration After Nerve Injury. Mol Neurobiol 2023; 60:1453-1464. [PMID: 36464749 DOI: 10.1007/s12035-022-03143-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Accepted: 11/17/2022] [Indexed: 12/11/2022]
Abstract
Motor function recovery from injury requires the regeneration of not only muscle fibers, but also the neuromuscular junction-the synapse between motor nerve terminals and muscle fibers. However, unlike muscle regeneration which has been extensively studied, little is known about the molecular mechanisms of NMJ regeneration. Recognizing the critical role of agrin-LRP4-MuSK signaling in NMJ formation and maintenance, we investigated whether increasing MuSK activity promotes NMJ regeneration. To this end, we evaluated the effect of DOK7, a protein that stimulates MuSK, on NMJ regeneration. Reinnervation, AChR cluster density, and endplate area were improved, and fragmentation was reduced in the AAV9-DOK7-GFP-injected muscles compared with muscles injected with AAV9-GFP. These results demonstrated expedited NMJ regeneration associated with increased DOK7 expression and support the hypothesis that increasing agrin signaling benefits motor function recovery after injury. Our findings propose a potentially new therapeutic strategy for functional recovery after muscle and nerve injury, i.e., promoting NMJ regeneration by increasing agrin signaling.
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15
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Guan Y, Li M, Qiu Z, Xu J, Zhang Y, Hu N, Zhang X, Guo W, Yuan J, Shi Q, Wang W. Comprehensive analysis of DOK family genes expression, immune characteristics, and drug sensitivity in human tumors. J Adv Res 2022; 36:73-87. [PMID: 35127166 PMCID: PMC8799871 DOI: 10.1016/j.jare.2021.06.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 05/31/2021] [Accepted: 06/09/2021] [Indexed: 02/07/2023] Open
Abstract
The expression of DOK family genes is related to overall survival (OS), clinical stage, tumor mutation, methylation, CNV, and SNV. DOK family genes are significantly associated with poor prognosis of UVM. DOK1-DOK3 has obvious correlation with tumor immunity and tumor microenvironment. DOK family gene is significantly related to tumor stemness and drug sensitivity. The expression of DOK family genes is related to the activation of EMT and hormone ER pathways, and is related to the inhibition of DNA damage response, cell cycle, and hormone AR pathways. DOK1 and DOK3, DOK2 and DOK3 have the significant correlation.
Introduction Objectives Methods Results Conclusions
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16
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The Neuromuscular Junction: Roles in Aging and Neuromuscular Disease. Int J Mol Sci 2021; 22:ijms22158058. [PMID: 34360831 PMCID: PMC8347593 DOI: 10.3390/ijms22158058] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 07/20/2021] [Accepted: 07/22/2021] [Indexed: 02/07/2023] Open
Abstract
The neuromuscular junction (NMJ) is a specialized synapse that bridges the motor neuron and the skeletal muscle fiber and is crucial for conversion of electrical impulses originating in the motor neuron to action potentials in the muscle fiber. The consideration of contributing factors to skeletal muscle injury, muscular dystrophy and sarcopenia cannot be restricted only to processes intrinsic to the muscle, as data show that these conditions incur denervation-like findings, such as fragmented NMJ morphology and corresponding functional changes in neuromuscular transmission. Primary defects in the NMJ also influence functional loss in motor neuron disease, congenital myasthenic syndromes and myasthenia gravis, resulting in skeletal muscle weakness and heightened fatigue. Such findings underscore the role that the NMJ plays in neuromuscular performance. Regardless of cause or effect, functional denervation is now an accepted consequence of sarcopenia and muscle disease. In this short review, we provide an overview of the pathologic etiology, symptoms, and therapeutic strategies related to the NMJ. In particular, we examine the role of the NMJ as a disease modifier and a potential therapeutic target in neuromuscular injury and disease.
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17
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Sugita S, Tamura K, Yano M, Minegishi Y, Ota N. The Impact of Milk Fat Globule Membrane with Exercise on Age-Related Degeneration of Neuromuscular Junctions. Nutrients 2021; 13:nu13072310. [PMID: 34371820 PMCID: PMC8308682 DOI: 10.3390/nu13072310] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 06/28/2021] [Accepted: 06/30/2021] [Indexed: 12/19/2022] Open
Abstract
Morphological changes in neuromuscular junctions (NMJs), which are synapses formed between α-motor neurons and skeletal muscle fibers, are considered to be important in age-related motor dysfunction. We have previously shown that the intake of dietary milk fat globule membrane (MFGM) combined with exercise attenuates age-related NMJ alterations in the early phase of aging. However, it is unclear whether the effect of MFGM with exercise on age-related NMJ alterations persists into old age, and whether intervention from old age is still effective when age-related changes in NMJs have already occurred. In this study, 6- or 18-month-old mice were treated with a 1% MFGM diet and daily running wheel exercise until 23 or 24 months of age, respectively. MFGM treatment with exercise was effective in suppressing the progression of age-related NMJ alterations in old age, and even after age-related changes in NMJs had already occurred. Moreover, the effect of MFGM intake with exercise was not restricted to NMJs but extended to the structure and function of peripheral nerves. This study demonstrates that MFGM intake with exercise may be a novel approach for improving motor function in the elderly by suppressing age-related NMJ alterations.
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18
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Jang SH, Lee J, Lee O. Micro- and nano-tomography analysis of mouse soleus muscle using radiation. Microsc Res Tech 2021; 84:2685-2693. [PMID: 34021519 DOI: 10.1002/jemt.23819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2021] [Revised: 04/13/2021] [Accepted: 05/02/2021] [Indexed: 11/10/2022]
Abstract
In this study, we analyze radiation images of muscle structure of mice soleus muscles using radiation source-based microtomography and nanotomography. Soleus muscle samples were collected for analysis from 8-week-old male Institute of Cancer Research mice. First, phase-contrast X-ray microtomography was employed in these experiments. Then to obtain images with excellent contrast, imaging was performed using monochromatic light with excellent transmission power. To analyze additional muscle structures in higher magnification images than these images, nanotomography was performed, which facilitated obtaining high-magnification and high-resolution images. Muscle tissue microstructures were confirmed through three-dimensional images obtained from phase-contrast X-ray microtomography. Thus, the muscle tissue's overall shape at microscopic level can be captured. Additionally, a single muscle fiber was examined using hard X-ray nano-imaging, through which we could observe the alignment of countless myofibrils, that is, actin and myosin filaments in the muscle fibers. Thus, the methodology adopted here proved to be advantageous in analyzing the muscle tissue's overall structure with microtomography and in observing the myofibrils in detail using nanotomography.
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Affiliation(s)
- Sang-Hun Jang
- Department of Physical Therapy, College of Health and Life Science, Korea National University of Transportation, Jeungpyeong-eup, Chungbuk, Republic of Korea
| | - Jiwon Lee
- Department of Software Convergence, Graduate School, Soonchunhyang University, Asan City, Chungnam, Republic of Korea
| | - Onseok Lee
- Department of Software Convergence, Graduate School, Soonchunhyang University, Asan City, Chungnam, Republic of Korea.,Department of Medical IT Engineering, College of Medical Sciences, Soonchunhyang University, Asan City, Chungnam, Republic of Korea
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19
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Badawi Y, Nishimune H. Impairment Mechanisms and Intervention Approaches for Aged Human Neuromuscular Junctions. Front Mol Neurosci 2020; 13:568426. [PMID: 33328881 PMCID: PMC7717980 DOI: 10.3389/fnmol.2020.568426] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 10/16/2020] [Indexed: 12/19/2022] Open
Abstract
The neuromuscular junction (NMJ) is a chemical synapse formed between a presynaptic motor neuron and a postsynaptic muscle cell. NMJs in most vertebrate species share many essential features; however, some differences distinguish human NMJs from others. This review will describe the pre- and postsynaptic structures of human NMJs and compare them to NMJs of laboratory animals. We will focus on age-dependent declines in function and changes in the structure of human NMJs. Furthermore, we will describe insights into the aging process revealed from mouse models of accelerated aging. In addition, we will compare aging phenotypes to other human pathologies that cause impairments of pre- and postsynaptic structures at NMJs. Finally, we will discuss potential intervention approaches for attenuating age-related NMJ dysfunction and sarcopenia in humans.
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Affiliation(s)
- Yomna Badawi
- Department of Anatomy and Cell Biology, University of Kansas School of Medicine, Kansas City, KS, United States
| | - Hiroshi Nishimune
- Department of Anatomy and Cell Biology, University of Kansas School of Medicine, Kansas City, KS, United States.,Neurobiology of Aging, Tokyo Metropolitan Institute of Gerontology, Itabashi, Japan
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