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Rink-Notzon S, Reuscher J, Wollny L, Sarikcioglu L, Bilmen S, Manthou M, Gordon T, Angelov DN. Appropriate dosage, timing, and site of intramuscular injections of brain-derived neurotrophic factor (BDNF) promote motor recovery after facial nerve injury in rats. Muscle Nerve 2024; 69:490-497. [PMID: 38328996 DOI: 10.1002/mus.28051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 01/18/2024] [Accepted: 01/21/2024] [Indexed: 02/09/2024]
Abstract
INTRODUCTION/AIMS Daily intramuscular injections of fibroblast growth factor 2 (FGF2) but not of brain-derived neurotrophic factor (BDNF) significantly improve whisking behavior and mono-innervation of the rat levator labii superioris (LLS) muscle 56 days after buccal nerve transection and suture (buccal-buccal anastomosis, BBA). We explored the dose-response of BDNF, FGF2, and insulin growth factor 2 (IGF2) on the same parameters, asking whether higher doses of BDNF would promote recovery. METHODS After BBA, growth factors were injected (30 μL volume) daily into the LLS muscle over 14, 28, or 56 days. At 56 days, video-based motion analysis of vibrissal whisking was performed and the extent of mono- and poly-reinnervation of the reinnervated neuromuscular junctions (NMJs) of the muscle determined with immunostaining of the nerve with β-tubulin and histochemical staining of the endplates with Alexa Fluor 488-conjugated α-bungarotoxin. RESULTS The dose-response curve demonstrated significantly higher whisking amplitudes and corresponding increased mono-innervation of the NMJ in the reinnervated LLS muscle at concentrations of 20-30 μg/mL BDNF administered daily for 14-28 days after BBA surgery. In contrast, high doses of IGF2 and FGF2, or doses of 20 and 40 μg/mL of BDNF administered for 14-56 days had no effect on either whisking behavior or in reducing poly-reinnervation of endplates in the muscle. DISCUSSION These data suggest that the re-establishment of mono-innervation of whiskerpad muscles and the improved motor function by injections of BDNF into the paralyzed vibrissal musculature after facial nerve injury have translation potential and promote clinical application.
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Affiliation(s)
- Svenja Rink-Notzon
- Department of Prosthetic Dentistry, School of Dental and Oral Medicine, University of Cologne, Cologne, Germany
| | - Jannika Reuscher
- Department of Anatomy II, University of Cologne, Cologne, Germany
| | - Laura Wollny
- Department of Anatomy II, University of Cologne, Cologne, Germany
| | | | - Süreyya Bilmen
- Vocational School of Health Services, Akdeniz University, Antalya, Turkey
| | - Marilena Manthou
- Department of Histology and Embryology, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Tessa Gordon
- Department of Surgery, The Hospital for Sick Children, Toronto, Ontario, Canada
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Qiao J, Gu JY, Li B. Differences in neuromuscular junctions between intrinsic muscles of the forepaw and biceps muscles in rats. Histol Histopathol 2024; 39:525-531. [PMID: 37902551 DOI: 10.14670/hh-18-667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2023]
Abstract
Motor endplates of the interossei muscles become destabilized, whereas those of the biceps muscles remain stable in a rat model of obstetric brachial plexus palsy. However, it is unclear whether the morphology of the motor endplates of the interossei muscles is different from that of the biceps muscles in normal rat. We hypothesized that the motor endplates in the interossei muscles have specific characteristics different from those in the biceps muscles. The motor endplates were labeled with α-bungarotoxin and synaptophysin. The cross-sectional areas of the muscle fibers, the morphologies of the motor endplates, and the absolute and normalized areas (corrected by muscle fiber diameter) of the motor endplates of the interossei muscles and the biceps muscles were compared in rats at 1, 3, and 5 weeks after birth. The cross-sectional area of the interossei muscles and biceps muscle fibers were found to have increased gradually at 1, 3, and 5 weeks, but that of the biceps muscles was larger than that of the interossei muscles. The motor endplates of the interossei muscles and the biceps muscles gradually develop from crescent to pretzel shape after birth, and those of the interossei muscles have a smaller area. At 1, 3, and 5 weeks postnatally, the area of postnatal normalized motor endplates of the interossei muscles was much smaller than that of the biceps muscles. A better understanding of the morphological differences of the motor endplates between the interossei muscles and the biceps muscles may help to understand their physiological and pathological changes.
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Affiliation(s)
- Jing Qiao
- Department of Plastic Surgery, Huashan Hospital Affiliated to Fudan University, Shanghai, China
| | - Jing-Yu Gu
- Department of Neurology,Seventh People's Hospital of Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Bo Li
- Department of Orthopedic Surgery, Yangpu Hospital, School of Medicine, Tongji University, Shanghai, China.
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Skov M, Ruijs TQ, Grønnebæk TS, Skals M, Riisager A, Winther JB, Dybdahl KLT, Findsen A, Morgen JJ, Huus N, Broch-Lips M, Nielsen OB, de Cuba CMKE, Heuberger JAAC, de Kam ML, Tannemaat M, Verschuuren JJGM, Knutsen LJS, Kelly NM, Jensen KG, Arnold WD, Burghes AH, Olesen C, Bold J, Petersen TK, Quiroz JA, Hutchison J, Chin ER, Groeneveld GJ, Pedersen TH. The ClC-1 chloride channel inhibitor NMD670 improves skeletal muscle function in rat models and patients with myasthenia gravis. Sci Transl Med 2024; 16:eadk9109. [PMID: 38507469 DOI: 10.1126/scitranslmed.adk9109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Accepted: 02/23/2024] [Indexed: 03/22/2024]
Abstract
Myasthenia gravis (MG) is a neuromuscular disease that results in compromised transmission of electrical signals at the neuromuscular junction (NMJ) from motor neurons to skeletal muscle fibers. As a result, patients with MG have reduced skeletal muscle function and present with symptoms of severe muscle weakness and fatigue. ClC-1 is a skeletal muscle specific chloride (Cl-) ion channel that plays important roles in regulating neuromuscular transmission and muscle fiber excitability during intense exercise. Here, we show that partial inhibition of ClC-1 with an orally bioavailable small molecule (NMD670) can restore muscle function in rat models of MG and in patients with MG. In severely affected MG rats, ClC-1 inhibition enhanced neuromuscular transmission, restored muscle function, and improved mobility after both single and prolonged administrations of NMD670. On this basis, NMD670 was progressed through nonclinical safety pharmacology and toxicology studies, leading to approval for testing in clinical studies. After successfully completing phase 1 single ascending dose in healthy volunteers, NMD670 was tested in patients with MG in a randomized, placebo-controlled, single-dose, three-way crossover clinical trial. The clinical trial evaluated safety, pharmacokinetics, and pharmacodynamics of NMD670 in 12 patients with mild MG. NMD670 had a favorable safety profile and led to clinically relevant improvements in the quantitative myasthenia gravis (QMG) total score. This translational study spanning from single muscle fiber recordings to patients provides proof of mechanism for ClC-1 inhibition as a potential therapeutic approach in MG and supports further development of NMD670.
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Affiliation(s)
- Martin Skov
- NMD Pharma A/S, Palle Juul-Jensens Boulevard 82, 8200 Aarhus N, Denmark
| | - Titia Q Ruijs
- Centre for Human Drug Research, 2333 CL Leiden, Netherlands
- Leiden University Medical Centre, 2333 ZA Leiden, Netherlands
| | | | - Marianne Skals
- NMD Pharma A/S, Palle Juul-Jensens Boulevard 82, 8200 Aarhus N, Denmark
| | - Anders Riisager
- NMD Pharma A/S, Palle Juul-Jensens Boulevard 82, 8200 Aarhus N, Denmark
| | | | | | - Anders Findsen
- NMD Pharma A/S, Palle Juul-Jensens Boulevard 82, 8200 Aarhus N, Denmark
| | - Jeanette J Morgen
- NMD Pharma A/S, Palle Juul-Jensens Boulevard 82, 8200 Aarhus N, Denmark
| | - Nete Huus
- NMD Pharma A/S, Palle Juul-Jensens Boulevard 82, 8200 Aarhus N, Denmark
| | - Martin Broch-Lips
- NMD Pharma A/S, Palle Juul-Jensens Boulevard 82, 8200 Aarhus N, Denmark
| | - Ole B Nielsen
- NMD Pharma A/S, Palle Juul-Jensens Boulevard 82, 8200 Aarhus N, Denmark
- Department of Biomedicine, Aarhus University, Ole Worms Alle 4, 8000 Aarhus C, Denmark
| | - Catherine M K E de Cuba
- Centre for Human Drug Research, 2333 CL Leiden, Netherlands
- Leiden University Medical Centre, 2333 ZA Leiden, Netherlands
| | | | | | | | | | - Lars J S Knutsen
- NMD Pharma A/S, Palle Juul-Jensens Boulevard 82, 8200 Aarhus N, Denmark
| | - Nicholas M Kelly
- NMD Pharma A/S, Palle Juul-Jensens Boulevard 82, 8200 Aarhus N, Denmark
| | - Klaus G Jensen
- NMD Pharma A/S, Palle Juul-Jensens Boulevard 82, 8200 Aarhus N, Denmark
| | - William D Arnold
- NextGen Precision Health, University of Missouri, 1030 Hitt St, Columbia, MO 65212, USA
| | - Arthur H Burghes
- Department of Biological Chemistry and Pharmacology, Ohio State University Wexner Medical Center, 1060 Carmack Road, Columbus, OH 43210, USA
- Department of Neurology, Neuromuscular Division, Ohio State University Wexner Medical Center, 395 W. 12(th) Ave, Columbus, OH 43210, USA
| | - Claus Olesen
- NMD Pharma A/S, Palle Juul-Jensens Boulevard 82, 8200 Aarhus N, Denmark
- Department of Biomedicine, Aarhus University, Ole Worms Alle 4, 8000 Aarhus C, Denmark
| | - Jane Bold
- NMD Pharma A/S, Palle Juul-Jensens Boulevard 82, 8200 Aarhus N, Denmark
| | - Thomas K Petersen
- NMD Pharma A/S, Palle Juul-Jensens Boulevard 82, 8200 Aarhus N, Denmark
| | - Jorge A Quiroz
- NMD Pharma A/S, Palle Juul-Jensens Boulevard 82, 8200 Aarhus N, Denmark
| | - John Hutchison
- NMD Pharma A/S, Palle Juul-Jensens Boulevard 82, 8200 Aarhus N, Denmark
| | - Eva R Chin
- NMD Pharma A/S, Palle Juul-Jensens Boulevard 82, 8200 Aarhus N, Denmark
| | - Geert J Groeneveld
- Centre for Human Drug Research, 2333 CL Leiden, Netherlands
- Leiden University Medical Centre, 2333 ZA Leiden, Netherlands
| | - Thomas H Pedersen
- NMD Pharma A/S, Palle Juul-Jensens Boulevard 82, 8200 Aarhus N, Denmark
- Department of Biomedicine, Aarhus University, Ole Worms Alle 4, 8000 Aarhus C, Denmark
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Winther JB, Morgen JJ, Skov M, Broch-Lips MG, Nielsen OB, Overgaard K, Pedersen TH. Role of recovery of acetylcholine release in compromised neuromuscular junction function. Neuromuscul Disord 2024; 36:48-59. [PMID: 38359767 DOI: 10.1016/j.nmd.2024.01.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 12/17/2023] [Accepted: 01/22/2024] [Indexed: 02/17/2024]
Abstract
Everyday physical activities, such as walking, are enabled by repeated skeletal muscle contractions and require a well-functioning neuromuscular transmission. In myasthenic disorders, activities of daily living are debilitated by a compromised neuromuscular transmission leading to muscle weakness and fatiguability in patients. To enable physical activity, acetylcholine (ACh) is released repeatedly from the motor nerve, however, the role of the nerve terminals' capacity to sustain ACh release to support repetitive contractions under compromised neuromuscular transmission remains unclear. To explore this, we studied synaptic and contractile function during repeated contractions in healthy rat skeletal muscles under conditions of pharmacological induced compromised neuromuscular transmission. Using recordings of endplate potentials, compound muscle action potential (CMAP) and force production in isolated skeletal muscles and living, anesthetized animals, we found that force and CMAP were markedly reduced by even very light activity performed up to 5 s prior to contraction showing that recovery of ACh release was insufficient to maintain synaptic transmission strength. Our results suggest that the timing of depletion and restoration of ACh release may impact clinical signs of weakness and fatigability in patients with impaired neuromuscular transmission and affect the sensitivity of electromyographic recordings in the clinic.
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Affiliation(s)
| | | | - Martin Skov
- NMD Pharma A/S, Palle Juul-Jensens Blvd. 82, 8200 Aarhus N, Denmark
| | | | - Ole Bækgaard Nielsen
- Department of Public Health, Aarhus University, Bartholins Allé 2, 8000 Aarhus C, Denmark
| | - Kristian Overgaard
- Department of Public Health, Aarhus University, Bartholins Allé 2, 8000 Aarhus C, Denmark
| | - Thomas Holm Pedersen
- NMD Pharma A/S, Palle Juul-Jensens Blvd. 82, 8200 Aarhus N, Denmark; Department of Biomedicine, Aarhus University, Ole Worms Allé 4, 8000 Aarhus C, Denmark.
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Al Jabry T, Al-Hashmi N, Abdelhadi B, Al-Maawali A. LRP4 site-specific variants in the third β-propeller domain causes congenital myasthenic syndrome type 17. Eur J Med Genet 2024; 67:104903. [PMID: 38101565 DOI: 10.1016/j.ejmg.2023.104903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 10/23/2023] [Accepted: 12/12/2023] [Indexed: 12/17/2023]
Abstract
LRP4 is expressed in many organs. It mediates SOST-dependent inhibition of bone formation and acts as an inhibitor of WNT signaling. It is also a postsynaptic end plate cell surface receptor at the neuromuscular junction and is central to its development, maintenance, and function. Pathogenic variants of LRP4 that specifically affect the canonical WNT signaling pathway are known to be associated with Cenani-Lenz syndactyly syndrome or the overlapping condition sclerosteosis. However, site-specific pathogenic variants of LRP4 have been associated with the congenital myasthenic syndrome (CMS) type 17 with no abnormal bone phenotype. Only two studies reported biallelic variants of LRP4 associated with CMS17 that presented during childhood. All three reported variants (NM_002334.4: p.Glu1233Ala, p.Glu1233Lys, or p.Arg1277His) are located within the 3'-edge of the third β-propeller domain of LRP4. We report on a patient with a biallelic variant of the LRP4 gene presenting with a severe and neonatal lethal phenotype; we also provide a literature review of the previously reported patients. A female neonate, born to healthy consanguineous parents, presented with severe hypotonia, congenital diaphragmatic hernia, pulmonary hypertension, and progressive hypoxemia. Two of her siblings presented with a similar condition in the past, and all three died shortly after birth. Clinical exome sequencing revealed homozygosity for the pathogenic variant NM_002334.4:c.3698A > C (p.[Glu1233Ala]).
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Affiliation(s)
- Tariq Al Jabry
- Department of Genetics, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat, Oman
| | - Nadia Al-Hashmi
- National Genetic Center, and Department of Pediatrics, Royal Hospital, Muscat, Oman
| | - Basem Abdelhadi
- National Genetic Center, and Department of Pediatrics, Royal Hospital, Muscat, Oman
| | - Almundher Al-Maawali
- Department of Genetics, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat, Oman; Department of Genetics, Sultan Qaboos University Hospital, Muscat, Oman.
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Qaisar R, Karim A, Muhammad T, Ahmad F. Butyrate supplementation reduces sarcopenia by repairing neuromuscular junction in patients with chronic obstructive pulmonary disease. Respir Med 2024; 222:107510. [PMID: 38135194 DOI: 10.1016/j.rmed.2023.107510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 12/14/2023] [Accepted: 12/20/2023] [Indexed: 12/24/2023]
Abstract
INTRODUCTION Chronic obstructive pulmonary disease (COPD) is associated with an intestinal leak and neuromuscular junction (NMJ) degradation, which contributes to physical compromise and accelerated age-related muscle loss, called sarcopenia. However, the relevant interventions partly remain ineffective. We investigated the effects of exogenous butyrate on sarcopenia and physical capacity with relevance to intestinal permeability and NMJ integrity in COPD patients. METHODS COPD patients were randomized into placebo (n = 67) and butyrate (n = 64) groups in a double-blind manner. The patients in the butyrate group received one 300 mg capsule a day for 12 weeks. We measured circulating markers of intestinal leak (zonulin), systemic bacterial load (LBP), and NMJ loss (CAF22), along with handgrip strength (HGS), and short physical performance battery (SPPB) at baseline and 12 weeks. RESULTS Butyrate supplementation improved HGS and gait speed in COPD patients. Among SPPB indices, butyrate improved the ability to maintain postural balance and walking and prevented a decline in the ability to rise from a chair. Butyrate also reduced the plasma levels of zonulin, LBP, and CAF22 levels in COPD patients (all p < 0.05). Regression analysis revealed significant associations of plasma zonulin and CAF22 with HGS, gait speed, and cumulative SPPB scores in butyrate group. These changes were associated with reduced markers of inflammation and muscle damage. CONCLUSION Butyrate may provide a therapeutic approach to sarcopenia and physical dependency in COPD by repairing intestinal leak and NMJ loss.
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Affiliation(s)
- Rizwan Qaisar
- Basic Medical Sciences, College of Medicine, University of Sharjah, Sharjah, 27272, United Arab Emirates; Space Medicine Research Group, Research Institute of Medical and Health Sciences, University of Sharjah, Sharjah, 27272, United Arab Emirates; Cardiovascular Research Group, Research Institute of Medical and Health Sciences, University of Sharjah, Sharjah, 27272, United Arab Emirates.
| | - Asima Karim
- Basic Medical Sciences, College of Medicine, University of Sharjah, Sharjah, 27272, United Arab Emirates
| | - Tahir Muhammad
- Department of Biochemistry, Gomal Medical College, Gomal University, Dera Ismail Khan, 30130, Pakistan
| | - Firdos Ahmad
- Basic Medical Sciences, College of Medicine, University of Sharjah, Sharjah, 27272, United Arab Emirates; Space Medicine Research Group, Research Institute of Medical and Health Sciences, University of Sharjah, Sharjah, 27272, United Arab Emirates; Cardiovascular Research Group, Research Institute of Medical and Health Sciences, University of Sharjah, Sharjah, 27272, United Arab Emirates
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Panda PK, Sharawat IK. Myasthenia gravis and economic burden: Exploring the impact of family dynamics on financial strain. J Clin Neurosci 2024; 120:92-93. [PMID: 38237492 DOI: 10.1016/j.jocn.2024.01.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Accepted: 01/10/2024] [Indexed: 02/12/2024]
Affiliation(s)
- Prateek Kumar Panda
- Pediatric Neurology Division, Department of Pediatrics, All India Institute of Medical Sciences, Rishikesh, Uttarakhand 249203, India
| | - Indar Kumar Sharawat
- Pediatric Neurology Division, Department of Pediatrics, All India Institute of Medical Sciences, Rishikesh, Uttarakhand 249203, India.
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Shi J, Yi M, Xie S, Wang Z, Zhang X, Tan X, Tao D, Liu Y, Yang Y. Mendelian randomization study revealed a gut microbiota- neuromuscular junction axis in myasthenia gravis. Sci Rep 2024; 14:2473. [PMID: 38291090 PMCID: PMC10827739 DOI: 10.1038/s41598-024-52469-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 01/18/2024] [Indexed: 02/01/2024] Open
Abstract
A growing number of studies have implicated that gut microbiota abundance is associated with myasthenia gravis (MG). However, the causal relationship underlying the associations is still unclear. Here, we aim to investigate the causal effect of gut microbiota on MG using Mendelian randomization (MR) method. Publicly available Genome-wide association study (GWAS) summary-level data for gut microbiota and for MG were extracted. Inverse variance weighted was used as the main method to analyze causality. The robustness of the results was validated with sensitivity analyses. Our results indicated that genetically predicted increased phylum Lentisphaerae (OR = 1.319, p = 0.026), class Lentisphaerae (OR = 1.306, p = 0.044), order Victivallales (OR = 1.306, p = 0.044), order Mollicutes (OR = 1.424, p = 0.041), and genus Faecalibacterium (OR = 1.763, p = 0.002) were potentially associated with a higher risk of MG; while phylum Actinobacteria (OR = 0.602, p = 0.0124), class Gammaproteobacteria (OR = 0.587, p = 0.036), family Defluviitaleaceae (OR = 0.695, p = 0.047), family Peptococcaceae (OR = 0.698, p = 0.029), and family Family XIII (OR = 0.614, p = 0.017) were related to a lower risk of MG. The present study provides genetic evidence for the causal associations between gut microbiota and MG, thus suggesting novel insights into the gut microbiota-neuromuscular junction axis in the pathogenesis of MG.
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Affiliation(s)
- Jiaying Shi
- Department of Medical Genetics, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Ming Yi
- Department of Medical Genetics, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Shengyu Xie
- Department of Medical Genetics, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Zhaokun Wang
- Department of Medical Genetics, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Xinyue Zhang
- Department of Medical Genetics, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Xiaolan Tan
- Department of Medical Genetics, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Dachang Tao
- Department of Medical Genetics, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Yunqiang Liu
- Department of Medical Genetics, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Yuan Yang
- Department of Medical Genetics, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China.
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Behun MN, Kulkarni M, Nolfi AL, France CT, Skillen CD, Mahan MA, Soletti L, Brown BN. Porcine Acellular Nerve-Derived Hydrogel Improves Outcomes of Direct Muscle Neurotization in Rats. Tissue Eng Part A 2024; 30:84-93. [PMID: 37917102 DOI: 10.1089/ten.tea.2023.0191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2023] Open
Abstract
Background: The ability to reinnervate a muscle in the absence of a viable nerve stump is a challenging clinical scenario. Direct muscle neurotization (DMN) is an approach to overcome this obstacle; however, success depends on the formation of new muscle endplates, a process, which is often limited due to lack of appropriate axonal pathfinding cues. Objective: This study explored the use of a porcine nerve extracellular matrix hydrogel as a neuroinductive interface between nerve and muscle in a rat DMN model. The goal of the study was to establish whether such hydrogel can be used to improve neuromuscular function in this model. Materials and Methods: A common peroneal nerve-to-gastrocnemius model of DMN was developed. Animals were survived for 2 or 8 weeks following DMN with or without the addition of the hydrogel at the site of neurotization. Longitudinal postural thrust, terminal electrophysiology, and muscle weight assessments were performed to qualify and quantify neuromuscular function. Histological assessments were made to qualify the host response at the DMN site, and to quantify neuromuscular junctions (NMJs) and muscle fiber diameter. Results: The hydrogel-treated group showed a 132% increase in postural thrust at 8 weeks compared with that of the DMN alone group. This was accompanied by an 80% increase in the number of NMJs at 2 weeks, and 26% increase in mean muscle fiber diameter at 8 weeks. Conclusions: These results suggest that a nerve-derived hydrogel may improve the neuromuscular outcome following DNM.
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Affiliation(s)
- Marissa N Behun
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Mangesh Kulkarni
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Alexis L Nolfi
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Cambell T France
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Clint D Skillen
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Mark A Mahan
- Department of Neurosurgery, Clinical Neurosciences Center, University of Utah, Salt Lake City, Utah, USA
| | | | - Bryan N Brown
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Renerva, LLC, Pittsburgh, Pennsylvania, USA
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Wagle Shukla A. Basis of movement control in dystonia and why botulinum toxin should influence it? Toxicon 2024; 237:107251. [PMID: 37574115 DOI: 10.1016/j.toxicon.2023.107251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 07/31/2023] [Accepted: 08/10/2023] [Indexed: 08/15/2023]
Abstract
Dystonia is a network disorder involving multiple brain regions, such as the motor cortex, sensory cortex, basal ganglia, and cerebellum. Botulinum toxin (BoNT) is the first-line therapy for treating focal dystonia and is a potent molecule that blocks the release of acetylcholine at the peripheral neuromuscular junction. However, the clinical benefits of BoNT are not solely related to peripheral muscle relaxation or modulation of afferent input from the muscle spindle. An increasing body of evidence, albeit in smaller cohorts, has shown that BoNT leads to distant modulation of the pathological brain substrates implicated in dystonia. A single treatment session of BoNT has been observed to reduce excessive motor excitability and improve sensory processing. Furthermore, owing to plasticity effects that are induced by botulinum, neural reorganization of pathological networks occurs, presumably leading to defective motor programs of dystonia replaced with normal movement patterns. However, longitudinal studies investigating the effects of multiple treatment sessions in large, well-characterized homogenous cohorts of dystonia will provide further compelling evidence supporting central botulinum mechanisms.
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Affiliation(s)
- Aparna Wagle Shukla
- Department of Neurology, Fixel Institute for Neurological Diseases, University of Florida, 3009 Williston Road, Gainesville, 32608, Florida, United States.
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Inoue-Yamauchi A, Yamanashi Y. [Molecular Mechanisms Underlying the Formation and Maintenance of Neuromuscular Junctions and Development of NMJ-targeted Therapeutics]. Brain Nerve 2024; 76:61-67. [PMID: 38191141 DOI: 10.11477/mf.1416202559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/10/2024]
Abstract
Skeletal muscle is an essential organ for the motor functions and its defects are associated with functional impairments of other organs including brain. Muscle contraction is the fundamental skeletal muscle function and is strictly controlled by motor neuron, which requires neuromuscular junction (NMJ), a chemical synapse between motor nerve terminal and myotube (myofiber). Defects in NMJ cause various functional abnormalities of skeletal muscle including muscle weakness. This review presents an overview of the current understanding of signaling in NMJ formation and maintenance in skeletal muscle and the development of NMJ-targeted therapeutics.
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Affiliation(s)
- Akane Inoue-Yamauchi
- Division of Genetics, Department of Cancer Biology, The Institute of Medical Science, The University of Tokyo
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Durbin R, Renden R. Basal lamina: A novel pH regulator at the neuromuscular junction. Sci Prog 2024; 107:368504231225066. [PMID: 38196184 PMCID: PMC10777786 DOI: 10.1177/00368504231225066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2024]
Abstract
Proton concentration can change within the cleft during synaptic activity due to vesicular release and Ca2+ extrusion from cellular compartments. These changes within the synaptic cleft can impact neural activity by proton-dependent modulation of ion channel function. The pH transient differs in magnitude and direction between synapses, requiring different synapse types to be measured to generate a complete understanding of this mechanism and its impacts on physiology. With a focus on the mouse neuromuscular junction (NMJ), the recently published "Postsynaptic Calcium Extrusion at the Mouse Neuromuscular Junction Alkalinizes the Synaptic Cleft" measured synaptic cleft pH at a cholinergic synapse and found a biphasic pH transient. The study demonstrated that the changes in proton concentration found were due to postsynaptic signaling when measuring pH at the muscle membrane, despite the expectation of a presynaptic contribution. This result suggests a diffusional barrier within the NMJ isolates pH transients to presynaptic versus postsynaptic compartments. Generating a Donnan equilibrium that impacts protons, evidence suggests the basal lamina may be a key regulator of pH at the NMJ. Exploring synaptic pH, proton regulating factors, and downstream pH transient effects at presynaptic versus postsynaptic membranes may lead to new insight for a variety of diseases.
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Affiliation(s)
- Ryan Durbin
- Department of Physiology and Cell Biology, University of Nevada, Reno, School of Medicine, Reno, NV, USA
| | - Robert Renden
- Department of Physiology and Cell Biology, University of Nevada, Reno, School of Medicine, Reno, NV, USA
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13
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Mrestani A, Dannhäuser S, Pauli M, Kollmannsberger P, Hübsch M, Morris L, Langenhan T, Heckmann M, Paul MM. Nanoscaled RIM clustering at presynaptic active zones revealed by endogenous tagging. Life Sci Alliance 2023; 6:e202302021. [PMID: 37696575 PMCID: PMC10494931 DOI: 10.26508/lsa.202302021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 08/27/2023] [Accepted: 08/28/2023] [Indexed: 09/13/2023] Open
Abstract
Chemical synaptic transmission involves neurotransmitter release from presynaptic active zones (AZs). The AZ protein Rab-3-interacting molecule (RIM) is important for normal Ca2+-triggered release. However, its precise localization within AZs of the glutamatergic neuromuscular junctions of Drosophila melanogaster remains elusive. We used CRISPR/Cas9-assisted genome engineering of the rim locus to incorporate small epitope tags for targeted super-resolution imaging. A V5-tag, derived from simian virus 5, and an HA-tag, derived from human influenza virus, were N-terminally fused to the RIM Zinc finger. Whereas both variants are expressed in co-localization with the core AZ scaffold Bruchpilot, electrophysiological characterization reveals that AP-evoked synaptic release is disturbed in rimV5-Znf but not in rimHA-Znf In addition, rimHA-Znf synapses show intact presynaptic homeostatic potentiation. Combining super-resolution localization microscopy and hierarchical clustering, we detect ∼10 RIMHA-Znf subclusters with ∼13 nm diameter per AZ that are compacted and increased in numbers in presynaptic homeostatic potentiation.
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Affiliation(s)
- Achmed Mrestani
- https://ror.org/00fbnyb24 Department of Neurophysiology, Institute of Physiology, University of Würzburg, Würzburg, Germany
- Department of Neurology, Leipzig University Medical Center, Leipzig, Germany
- Division of General Biochemistry, Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, Leipzig University, Leipzig, Germany
| | - Sven Dannhäuser
- https://ror.org/00fbnyb24 Department of Neurophysiology, Institute of Physiology, University of Würzburg, Würzburg, Germany
| | - Martin Pauli
- https://ror.org/00fbnyb24 Department of Neurophysiology, Institute of Physiology, University of Würzburg, Würzburg, Germany
| | | | - Martha Hübsch
- https://ror.org/00fbnyb24 Department of Neurophysiology, Institute of Physiology, University of Würzburg, Würzburg, Germany
| | - Lydia Morris
- Division of General Biochemistry, Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, Leipzig University, Leipzig, Germany
| | - Tobias Langenhan
- Division of General Biochemistry, Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, Leipzig University, Leipzig, Germany
| | - Manfred Heckmann
- https://ror.org/00fbnyb24 Department of Neurophysiology, Institute of Physiology, University of Würzburg, Würzburg, Germany
| | - Mila M Paul
- https://ror.org/00fbnyb24 Department of Neurophysiology, Institute of Physiology, University of Würzburg, Würzburg, Germany
- https://ror.org/03pvr2g57 Department of Orthopedic Trauma, Hand, Plastic and Reconstructive Surgery, University Hospital of Würzburg, Würzburg, Germany
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Lacomis D. What Is in the Neuromuscular Junction Literature? J Clin Neuromuscul Dis 2023; 25:107-114. [PMID: 37962198 DOI: 10.1097/cnd.0000000000000456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
ABSTRACT This update covers several articles on diagnosis and misdiagnosis of myasthenia gravis (MG), the role of complement in MG, and then an impressive number of recent treatment trials. There is a negative study on any corticosteroid-sparing effect of intravenous immunoglobulin. A number of positive studies are reviewed. Open-label extension studies of phase 3 trials showed benefit regarding quality of life with efgartigimod and in functional measures with ravulizumab. The phase 3 RAISE trial of zilucoplan, a self-administered complement C5 inhibitor, is covered as well as the MyCarinG trial of rozanolixizumab. The notion of using fast-acting therapies early in the course of MG is addressed. The last sections center on MG and Lambert-Eaton myasthenic syndrome as a consequence of immune checkpoint inhibitor therapy.
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Affiliation(s)
- David Lacomis
- Departments of Neurology; and
- Pathology (Neuropathology), University of Pittsburgh School of Medicine, Pittsburgh, PA
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Luo J, Sun A, Yu Y, Pei Y, Zuo Y, Hu Z. Periplocoside P affects synaptic transmission at the neuromuscular junction and reduces synaptic excitability in Drosophila melanogaster by inhibiting V-ATPase. Pest Manag Sci 2023; 79:5044-5052. [PMID: 37556562 DOI: 10.1002/ps.7705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 08/02/2023] [Accepted: 08/04/2023] [Indexed: 08/11/2023]
Abstract
BACKGROUND Periplocoside P (PSP) is a major component of Periploca sepium Bunge known for its potent insecticidal activity. V-Type adenosine triphosphatase (V-ATPase), which is widely distributed in the cytoplasmic membranes and organelles of eukaryotic cells, plays a crucial role in synaptic excitability conduction. Previous research has shown that PSP targets the apical membrane of goblet cells in the insect midgut. However, the effects of PSP on synaptic transmission at the neuromuscular junction are often overlooked. RESULTS The bioassay revealed that Drosophila adults with different genetic backgrounds showed varying levels of susceptibility to PSP in the order: parats1 > parats1 ;DSC1-/- ≈ w1118 > DSC1-/- . Intracellular electrode recording demonstrated that PSP, similar to bafilomycin A1, had an impact on the amplitude of the excitatory junction potential (EJP) and accelerated excitability decay. Furthermore, the alteration in EJP amplitude is concentration-dependent. Another surprising discovery was that the knockout DSC1 channel showed insensitivity to PSP. CONCLUSION Our findings confirm that PSP can influence synaptic transmission at the neuromuscular junction of Drosophila larvae by targeting V-ATPase. These results provide a basis for investigating the mechanism of action of PSP and its potential application in designing novel insecticides. © 2023 Society of Chemical Industry.
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Affiliation(s)
- Jiaojiao Luo
- Institute of Pesticide Science, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
- Key Laboratory for Botanical Pesticide R&D of Shaanxi Province, Northwest A&F University, Yangling, Shaanxi, China
| | - Anqi Sun
- Institute of Pesticide Science, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
- Key Laboratory for Botanical Pesticide R&D of Shaanxi Province, Northwest A&F University, Yangling, Shaanxi, China
| | - Yang Yu
- Institute of Pesticide Science, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
- Key Laboratory for Botanical Pesticide R&D of Shaanxi Province, Northwest A&F University, Yangling, Shaanxi, China
| | - Yakun Pei
- Institute of Pesticide Science, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
- Key Laboratory for Botanical Pesticide R&D of Shaanxi Province, Northwest A&F University, Yangling, Shaanxi, China
| | - Yayun Zuo
- Institute of Pesticide Science, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
- Key Laboratory for Botanical Pesticide R&D of Shaanxi Province, Northwest A&F University, Yangling, Shaanxi, China
- Key Laboratory of Plant Protection Resources and Pest Management of Ministry of Education, Northwest A&F Univeristy, Yangling, Shaanxi, China
| | - Zhaonong Hu
- Institute of Pesticide Science, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
- Key Laboratory for Botanical Pesticide R&D of Shaanxi Province, Northwest A&F University, Yangling, Shaanxi, China
- Key Laboratory of Plant Protection Resources and Pest Management of Ministry of Education, Northwest A&F Univeristy, Yangling, Shaanxi, China
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Kouyoumdjian JA, Estephan EDP. Electrophysiological evaluation of the neuromuscular junction: a brief review. Arq Neuropsiquiatr 2023; 81:1040-1052. [PMID: 38157872 PMCID: PMC10756823 DOI: 10.1055/s-0043-1777749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 11/17/2023] [Indexed: 01/03/2024]
Abstract
The nerve terminal and muscle membrane compose the neuromuscular junction. After opening the voltage-gated calcium channels, action potentials from the motor axons provoke a cascade for the acetylcholine release from synaptic vesicles to the synaptic cleft, where it binds to its receptor at the muscle membrane for depolarization. Low amplitude compound muscle action potential typically presents in presynaptic disorders, increasing by more than 100% after a 10-second effort in the Lambert-Eaton myasthenic syndrome and less in botulism. Needle electromyography may show myopathic motor unit action potentials and morphological instability ("jiggle") due to impulse blocking. Low-frequency repetitive nerve stimulation (RNS) is helpful in postsynaptic disorders, such as myasthenia gravis and most congenital myasthenic syndromes, where the number of functioning acetylcholine receptors is reduced. Low-frequency RNS with a decrement >10% is abnormal when comparing the 4th to the first compound muscle action potential amplitude. High-frequency RNS is helpful in presynaptic disorders like Lambert-Eaton myasthenic syndrome, botulism, and some rare congenital myasthenic syndromes. The high-frequency RNS releases more calcium, increasing the acetylcholine with a compound muscle action potential increment. Concentric needle records apparent single-fiber action potentials (spikes). A voluntary activation measures the jitter between spikes from two endplates. An electrical activation measures the jitter of one spike (one endplate). The jitter is the most sensitive test for detecting a neuromuscular junction dysfunction. Most neuromuscular junction disorders are responsive to treatment.
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Affiliation(s)
- João Aris Kouyoumdjian
- Faculdade de Medicina de São José do Rio Preto, Departamento de Ciências Neurológicas, Psiquiatria e Psicologia Médica, São José do Rio Preto SP, Brazil.
| | - Eduardo de Paula Estephan
- Faculdade de Medicina de São José do Rio Preto, Departamento de Ciências Neurológicas, Psiquiatria e Psicologia Médica, São José do Rio Preto SP, Brazil.
- Universidade de São Paulo, Departamento de Neurologia, São Paulo SP, Brazil.
- Faculdade de Medicina Santa Marcelina, São Paulo SP, Brazil.
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Kim H, Kim GS, Hyun SH, Kim E. Advancements in 2D and 3D In Vitro Models for Studying Neuromuscular Diseases. Int J Mol Sci 2023; 24:17006. [PMID: 38069329 PMCID: PMC10707046 DOI: 10.3390/ijms242317006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2023] [Revised: 11/28/2023] [Accepted: 11/29/2023] [Indexed: 12/18/2023] Open
Abstract
Neuromuscular diseases (NMDs) are a genetically or clinically heterogeneous group of diseases that involve injury or dysfunction of neuromuscular tissue components, including peripheral motor neurons, skeletal muscles, and neuromuscular junctions. To study NMDs and develop potential therapies, remarkable progress has been made in generating in vitro neuromuscular models using engineering approaches to recapitulate the complex physical and biochemical microenvironments of 3D human neuromuscular tissues. In this review, we discuss recent studies focusing on the development of in vitro co-culture models of human motor neurons and skeletal muscles, with the pros and cons of each approach. Furthermore, we explain how neuromuscular in vitro models recapitulate certain aspects of specific NMDs, including amyotrophic lateral sclerosis and muscular dystrophy. Research on neuromuscular organoids (NMO) will continue to co-develop to better mimic tissues in vivo and will provide a better understanding of the development of the neuromuscular tissue, mechanisms of NMD action, and tools applicable to preclinical studies, including drug screening and toxicity tests.
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Affiliation(s)
- Haneul Kim
- Laboratory of Molecular Diagnostics and Cell Biology, College of Veterinary Medicine, Gyeongsang National University, Jinju 52828, Republic of Korea;
| | - Gon Sup Kim
- Research Institute of Life Science, College of Veterinary Medicine, Gyeongsang National University, Jinju 52828, Republic of Korea;
| | - Sang-Hwan Hyun
- Laboratory of Veterinary Embryology and Biotechnology, Veterinary Medical Center and College of Veterinary Medicine, Chungbuk National University, Cheongju 28644, Republic of Korea;
- Institute for Stem Cell & Regenerative Medicine, Chungbuk National University, Chengju 28644, Republic of Korea
- Graduate School of Veterinary Biosecurity and Protection, Chungbuk National University, Cheongju 28644, Republic of Korea
| | - Eunhye Kim
- Laboratory of Molecular Diagnostics and Cell Biology, College of Veterinary Medicine, Gyeongsang National University, Jinju 52828, Republic of Korea;
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Zeng WX, Liu H, Hao Y, Qian KY, Tian FM, Li L, Yu B, Zeng XT, Gao S, Hu Z, Tong XJ. CaMKII mediates sexually dimorphic synaptic transmission at neuromuscular junctions in C. elegans. J Cell Biol 2023; 222:e202301117. [PMID: 37624117 PMCID: PMC10457463 DOI: 10.1083/jcb.202301117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 06/20/2023] [Accepted: 08/14/2023] [Indexed: 08/26/2023] Open
Abstract
Sexually dimorphic behaviors are ubiquitous throughout the animal kingdom. Although both sex-specific and sex-shared neurons have been functionally implicated in these diverse behaviors, less is known about the roles of sex-shared neurons. Here, we discovered sexually dimorphic cholinergic synaptic transmission in C. elegans occurring at neuromuscular junctions (NMJs), with males exhibiting increased release frequencies, which result in sexually dimorphic locomotion behaviors. Scanning electron microscopy revealed that males have significantly more synaptic vesicles (SVs) at their cholinergic synapses than hermaphrodites. Analysis of previously published transcriptome identified the male-enriched transcripts and focused our attention on UNC-43/CaMKII. We ultimately show that differential accumulation of UNC-43 at cholinergic neurons controls axonal SV abundance and synaptic transmission. Finally, we demonstrate that sex reversal of all neurons in hermaphrodites generates male-like cholinergic transmission and locomotion behaviors. Thus, beyond demonstrating UNC-43/CaMKII as an essential mediator of sex-specific synaptic transmission, our study provides molecular and cellular insights into how sex-shared neurons can generate sexually dimorphic locomotion behaviors.
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Affiliation(s)
- Wan-Xin Zeng
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
- Institute of Neuroscience, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Haowen Liu
- Queensland Brain Institute, Clem Jones Centre for Ageing Dementia Research (CJCADR), The University of Queensland, Brisbane, Australia
| | - Yue Hao
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
- Institute of Neuroscience, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Kang-Ying Qian
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
- Institute of Neuroscience, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Fu-Min Tian
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Lei Li
- Queensland Brain Institute, Clem Jones Centre for Ageing Dementia Research (CJCADR), The University of Queensland, Brisbane, Australia
| | - Bin Yu
- College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Xian-Ting Zeng
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Shangbang Gao
- College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Zhitao Hu
- Queensland Brain Institute, Clem Jones Centre for Ageing Dementia Research (CJCADR), The University of Queensland, Brisbane, Australia
- Department of Neuroscience, City University of Hong Kong, Kowloon, China
| | - Xia-Jing Tong
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
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Hastings RL, Avila MF, Suneby E, Juros D, O'Young A, Peres da Silva J, Valdez G. Cellular and molecular evidence that synaptic Schwann cells contribute to aging of mouse neuromuscular junctions. Aging Cell 2023; 22:e13981. [PMID: 37771191 PMCID: PMC10652323 DOI: 10.1111/acel.13981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 08/17/2023] [Accepted: 08/18/2023] [Indexed: 09/30/2023] Open
Abstract
Age-induced degeneration of the neuromuscular junction (NMJ) is associated with motor dysfunction and muscle atrophy. While the impact of aging on the NMJ presynapse and postsynapse is well-documented, little is known about the changes perisynaptic Schwann cells (PSCs), the synaptic glia of the NMJ, undergo during aging. Here, we examined PSCs in young, middle-aged, and old mice in three muscles with different susceptibility to aging. Using light and electron microscopy, we found that PSCs acquire age-associated cellular features either prior to or at the same time as the onset of NMJ degeneration. Notably, we found that aged PSCs fail to completely cap the NMJ even though they are more abundant in old compared with young mice. We also found that aging PSCs form processes that either intrude into the synaptic cleft or guide axonal sprouts to innervate other NMJs. We next profiled the transcriptome of PSCs and other Schwann cells (SCs) to identify mechanisms altered in aged PSCs. This analysis revealed that aged PSCs acquire a transcriptional pattern previously shown to promote phagocytosis that is absent in other SCs. It also showed that aged PSCs upregulate unique pro-inflammatory molecules compared to other aged SCs. Interestingly, neither synaptogenesis genes nor genes that are typically upregulated by repair SCs were induced in aged PSCs or other SCs. These findings provide insights into cellular and molecular mechanisms that could be targeted in PSCs to stave off the deleterious effects of aging on NMJs.
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Affiliation(s)
- Robert Louis Hastings
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, Rhode Island, USA
| | | | - Emma Suneby
- Molecular Biology, Cell Biology, & Biochemistry Graduate Program, Brown University, Providence, Rhode Island, USA
| | - Devin Juros
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, Rhode Island, USA
| | - Anson O'Young
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, Rhode Island, USA
| | - Jason Peres da Silva
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, Rhode Island, USA
| | - Gregorio Valdez
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, Rhode Island, USA
- Center for Translational Neuroscience, Robert J. and Nancy D. Carney Institute for Brain Science, and Center on the Biology of Aging, Brown University, Providence, Rhode Island, USA
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20
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He Y, Wang HP, Pan FY, Xu SH, Gao YF. Plasticity changes in neuromuscular junction morphology and related regulatory proteins in the hibernating ground squirrel. J Appl Physiol (1985) 2023; 135:1082-1091. [PMID: 37795532 DOI: 10.1152/japplphysiol.00334.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 09/28/2023] [Accepted: 10/03/2023] [Indexed: 10/06/2023] Open
Abstract
Skeletal muscle disuse atrophy can cause degenerative changes in neuromuscular junction morphology. Although Daurian ground squirrels (Spermophilus dauricus) are a natural anti-disuse animal model for studying muscle atrophy during hibernation, little is known about the morphological and regulatory mechanisms of their neuromuscular junctions. Here, we found that morphological indices of the soleus muscle were significantly lower during hibernation (torpor and interbout arousal) compared with pre-hibernation but recovered during post-hibernation. In the extensor digitorum longus muscle, neuromuscular junction morphology did not change significantly during hibernation. Agrin-Lrp4-MuSK is a key pathway for the formation and maintenance of the neuromuscular junction. Our results showed that low-density lipoprotein receptor-associated protein 4 (Lrp4) expression in the soleus (slow muscle) decreased by 46.2% in the interbout arousal group compared with the pre-hibernation group (P = 0.019), with recovery in the post-hibernation group. Compared with the pre-hibernation group, agrin expression in the extensor digitorum longus (fast muscle) increased by 67.0% in the interbout arousal group (P = 0.016). In conclusion, periodic up-regulation in agrin expression during interbout arousal may be involved in the maintenance of neuromuscular junction morphology in the extensor digitorum longus muscle during hibernation. The degenerative changes in neuromuscular junction morphology and the periodic decrease in Lrp4 protein expression in the soleus during hibernation, these changes recovered to the pre-hibernation levels in the post-hibernation group, exhibiting significant plasticity. This plasticity may be one of the important mechanisms for resisting disuse atrophy in hibernating animals.NEW & NOTEWORTHY This study is the first to explore the neuromuscular junction morphology of slow- and fast-twitch muscles in Daurian ground squirrels during different periods of hibernation. Results showed that the neuromuscular junction maintained stable morphology in the extensor digitorum longus muscle. The degenerative changes in neuromuscular junction morphology and the periodic decrease in Lrp4 protein expression in the soleus muscle during hibernation recovered in post-hibernation, exhibiting significant plasticity.
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Affiliation(s)
- Yue He
- Shaanxi Key Laboratory for Animal Conservation, College of Life Sciences, Northwest University, Xi'an, People's Republic of China
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi'an, People's Republic of China
| | - Hui-Ping Wang
- Shaanxi Key Laboratory for Animal Conservation, College of Life Sciences, Northwest University, Xi'an, People's Republic of China
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi'an, People's Republic of China
| | - Fang-Yang Pan
- Shaanxi Key Laboratory for Animal Conservation, College of Life Sciences, Northwest University, Xi'an, People's Republic of China
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi'an, People's Republic of China
| | - Shen-Hui Xu
- Shaanxi Key Laboratory for Animal Conservation, College of Life Sciences, Northwest University, Xi'an, People's Republic of China
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi'an, People's Republic of China
- Department of Digestive Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, People's Republic of China
- State Key Laboratory of Cancer Biology, Department of Pathology, Xijing Hospital and School of Basic Medicine, Fourth Military Medical University, Xi'an, People's Republic of China
| | - Yun-Fang Gao
- Shaanxi Key Laboratory for Animal Conservation, College of Life Sciences, Northwest University, Xi'an, People's Republic of China
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi'an, People's Republic of China
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Arkhipov AY, Fedorov NS, Nurullin LF, Khabibrakhmanov AN, Mukhamedyarov MA, Samigullin DV, Malomouzh AI. Activation of TRPV1 Channels Inhibits the Release of Acetylcholine and Improves Muscle Contractility in Mice. Cell Mol Neurobiol 2023; 43:4157-4172. [PMID: 37689594 DOI: 10.1007/s10571-023-01403-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 08/22/2023] [Indexed: 09/11/2023]
Abstract
TRPV1 represents a non-selective transient receptor potential cation channel found not only in sensory neurons, but also in motor nerve endings and in skeletal muscle fibers. However, the role of TRPV1 in the functioning of the neuromuscular junction has not yet been fully established. In this study, the Levator Auris Longus muscle preparations were used to assess the effect of pharmacological activation of TRPV1 channels on neuromuscular transmission. The presence of TRPV1 channels in the nerve terminal and in the muscle fiber was confirmed by immunohistochemistry. It was verified by electrophysiology that the TRPV1 channel agonist capsaicin inhibits the acetylcholine release, and this effect was completely absent after preliminary application of the TRPV1 channel blocker SB 366791. Nerve stimulation revealed an increase of amplitude of isometric tetanic contractions upon application of capsaicin which was also eliminated after preliminary application of SB 366791. Similar data were obtained during direct muscle stimulation. Thus, pharmacological activation of TRPV1 channels affects the functioning of both the pre- and postsynaptic compartment of the neuromuscular junction. A moderate decrease in the amount of acetylcholine released from the motor nerve allows to maintain a reserve pool of the mediator to ensure a longer signal transmission process, and an increase in the force of muscle contraction, in its turn, also implies more effective physiological muscle activity in response to prolonged stimulation. This assumption is supported by the fact that when muscle was indirect stimulated with a fatigue protocol, muscle fatigue was attenuated in the presence of capsaicin.
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Affiliation(s)
- Arsenii Y Arkhipov
- Laboratory of Biophysics of Synaptic Processes, Kazan Institute of Biochemistry and Biophysics, Federal Research Center, Kazan Scientific Center of Russian Academy of Sciences, 2/31 Lobachevsky Street, Box 261, Kazan, Russia, 420111
| | - Nikita S Fedorov
- Laboratory of Biophysics of Synaptic Processes, Kazan Institute of Biochemistry and Biophysics, Federal Research Center, Kazan Scientific Center of Russian Academy of Sciences, 2/31 Lobachevsky Street, Box 261, Kazan, Russia, 420111
- Kazan Federal University, 18 Kremlyovskaya Street, Kazan, Russia, 420008
| | - Leniz F Nurullin
- Laboratory of Biophysics of Synaptic Processes, Kazan Institute of Biochemistry and Biophysics, Federal Research Center, Kazan Scientific Center of Russian Academy of Sciences, 2/31 Lobachevsky Street, Box 261, Kazan, Russia, 420111
- Kazan State Medical University, 49 Butlerova Street, Kazan, Russia, 420012
| | | | | | - Dmitry V Samigullin
- Laboratory of Biophysics of Synaptic Processes, Kazan Institute of Biochemistry and Biophysics, Federal Research Center, Kazan Scientific Center of Russian Academy of Sciences, 2/31 Lobachevsky Street, Box 261, Kazan, Russia, 420111
- A.N. Tupolev Kazan National Research Technical University, 10, K. Marx Street, Kazan, Russia, 420111
| | - Artem I Malomouzh
- Laboratory of Biophysics of Synaptic Processes, Kazan Institute of Biochemistry and Biophysics, Federal Research Center, Kazan Scientific Center of Russian Academy of Sciences, 2/31 Lobachevsky Street, Box 261, Kazan, Russia, 420111.
- A.N. Tupolev Kazan National Research Technical University, 10, K. Marx Street, Kazan, Russia, 420111.
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22
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Tibúrcio FC, Leite APS, Muller KS, Pinto CG, Valentino E, Castro PATDS, Matsumura CY, de Carvalho SF, Matheus SMM. Effects of Nandrolone Decanoate on Skeletal Muscle and Neuromuscular Junction of Sedentary and Exercised Rats. Medicina (Kaunas) 2023; 59:1940. [PMID: 38003989 PMCID: PMC10673219 DOI: 10.3390/medicina59111940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 10/03/2023] [Accepted: 10/23/2023] [Indexed: 11/26/2023]
Abstract
Background and Objectives: Nandrolone decanoate (ND) is the most widely used among the anabolic androgenic steroids (AAS), synthetic substances derived from testosterone, to improve muscular and health gains associated with exercises. The AAS leads to physical performance enhancement and presents anti-aging properties, but its abuse is associated with several adverse effects. Supraphysiological doses of AAS with or without physical exercise can cause morphological and functional alterations in neuromuscular interactions. This study aims to investigate the effects of ND supraphysiological doses in neuromuscular interactions, focusing on the soleus muscle and its neuromuscular junctions (NMJs) in rats, associated or not with physical exercise. Materials and Methods: Forty male Sprague Dawley rats were divided into four groups: sedentary and exercised groups, with or without ND at the dose of 10 mg/kg/week. The animals were treated for eight weeks, with intramuscular injections, and the soleus muscle was collected for morphological analyses. Results: The supraphysiological doses of ND in the sedentary group caused muscle degeneration, evidenced by splitting fibers, clusters of small fibers, irregular myofibrils, altered sarcomeres, an increase in collagen deposition and in the number of type I muscle fibers (slow-twitch) and central nuclei, as well as a decrease in fibers with peripheral nuclei. On the other hand, in the ND exercise group, there was an increase in the NMJs diameter with scattering of its acetylcholine receptors, although no major morphological changes were found in the skeletal muscle. Thus, the alterations caused by ND in sedentary rats were partially reversed by physical exercise. Conclusions: The supraphysiological ND exposure in the sedentary rats promoted an increase in muscle oxidative pattern and adverse morphological alterations in skeletal muscle, resulting from damage or post-injury regeneration. In the ND-exercised rats, no major morphological changes were found. Thus, the physical exercise partially reversed the alterations caused by ND in sedentary rats.
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Affiliation(s)
- Felipe Cantore Tibúrcio
- Medical School, São Paulo State University (Unesp), Botucatu 18618-687, SP, Brazil; (F.C.T.); (A.P.S.L.); (K.S.M.); (C.G.P.)
- Division of Anatomy, Department of Structural and Functional Biology, Institute of Biosciences, São Paulo State University (Unesp), Botucatu 18618-689, SP, Brazil; (C.Y.M.)
| | - Ana Paula Silveira Leite
- Medical School, São Paulo State University (Unesp), Botucatu 18618-687, SP, Brazil; (F.C.T.); (A.P.S.L.); (K.S.M.); (C.G.P.)
- Division of Anatomy, Department of Structural and Functional Biology, Institute of Biosciences, São Paulo State University (Unesp), Botucatu 18618-689, SP, Brazil; (C.Y.M.)
| | - Kevin Silva Muller
- Medical School, São Paulo State University (Unesp), Botucatu 18618-687, SP, Brazil; (F.C.T.); (A.P.S.L.); (K.S.M.); (C.G.P.)
- Division of Anatomy, Department of Structural and Functional Biology, Institute of Biosciences, São Paulo State University (Unesp), Botucatu 18618-689, SP, Brazil; (C.Y.M.)
| | - Carina Guidi Pinto
- Medical School, São Paulo State University (Unesp), Botucatu 18618-687, SP, Brazil; (F.C.T.); (A.P.S.L.); (K.S.M.); (C.G.P.)
- Division of Anatomy, Department of Structural and Functional Biology, Institute of Biosciences, São Paulo State University (Unesp), Botucatu 18618-689, SP, Brazil; (C.Y.M.)
| | - Erick Valentino
- Division of Anatomy, Department of Structural and Functional Biology, Institute of Biosciences, São Paulo State University (Unesp), Botucatu 18618-689, SP, Brazil; (C.Y.M.)
| | - Paula Aiello Tomé de Souza Castro
- Department of Physical Therapy, Center for Biological and Health Sciences, Federal University of São Carlos (UFSCar), São Carlos 13565-905, SP, Brazil;
| | - Cintia Yuri Matsumura
- Division of Anatomy, Department of Structural and Functional Biology, Institute of Biosciences, São Paulo State University (Unesp), Botucatu 18618-689, SP, Brazil; (C.Y.M.)
| | - Shelly Favorito de Carvalho
- Electron Microscopy Center, Institute of Biosciences, São Paulo State University (Unesp), Botucatu 18618-689, SP, Brazil;
| | - Selma Maria Michelin Matheus
- Division of Anatomy, Department of Structural and Functional Biology, Institute of Biosciences, São Paulo State University (Unesp), Botucatu 18618-689, SP, Brazil; (C.Y.M.)
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23
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Wong P, Ashby O. Monitoring and Antagonism of Neuromuscular Blockade: Problems with Succinylcholine. Anesthesiology 2023; 139:712-714. [PMID: 37702620 DOI: 10.1097/aln.0000000000004705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/14/2023]
Affiliation(s)
- Patrick Wong
- Te Whatu Ora - Health New Zealand, Hamilton, Waikato, New Zealand (P.W.).
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24
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Gazzola M, Martinat C. Unlocking the Complexity of Neuromuscular Diseases: Insights from Human Pluripotent Stem Cell-Derived Neuromuscular Junctions. Int J Mol Sci 2023; 24:15291. [PMID: 37894969 PMCID: PMC10607237 DOI: 10.3390/ijms242015291] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 09/26/2023] [Accepted: 10/16/2023] [Indexed: 10/29/2023] Open
Abstract
Over the past 20 years, the use of pluripotent stem cells to mimic the complexities of the human neuromuscular junction has received much attention. Deciphering the key mechanisms underlying the establishment and maturation of this complex synapse has been driven by the dual goals of addressing developmental questions and gaining insight into neuromuscular disorders. This review aims to summarise the evolution and sophistication of in vitro neuromuscular junction models developed from the first differentiation of human embryonic stem cells into motor neurons to recent neuromuscular organoids. We also discuss the potential offered by these models to decipher different neuromuscular diseases characterised by defects in the presynaptic compartment, the neuromuscular junction, and the postsynaptic compartment. Finally, we discuss the emerging field that considers the use of these techniques in drug screening assay and the challenges they will face in the future.
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Affiliation(s)
- Morgan Gazzola
- INSERM U861, Institute for Stem Cell Therapy and Exploration of Monogenic Diseases, 91100 Corbeil-Essonnes, France;
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25
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Koral G, Ulusoy C, Cossins J, Lazaridis K, Türkoğlu R, Dong YY, Tüzün E, Yılmaz V. Silencing of FCRLB by shRNA ameliorates MuSK-induced EAMG in mice. J Neuroimmunol 2023; 383:578195. [PMID: 37660538 DOI: 10.1016/j.jneuroim.2023.578195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2023] [Revised: 05/18/2023] [Accepted: 08/29/2023] [Indexed: 09/05/2023]
Abstract
INTRODUCTION Muscle specific kinase (MuSK) antibody positive myasthenia gravis (MG) often presents with a severe disease course and resistance to treatment. Treatment-refractory patients may respond to B cell depleting treatment methods. Our aim was to investigate whether inhibition of Fc receptor-like B (FCRLB) could effectively suppress autoimmunity without diminishing B cell counts in animal model of MG, a classical antibody-mediated autoimmune disease. METHODS Experimental autoimmune MG was induced in Balb/C mice with two s.c. immunizations with recombinant human MuSK in complete Freund's adjuvant. FCRLB was silenced with a lentiviral particle transported shRNA in myasthenic mice with a single i.p. injection during second MuSK-immunization. Control immunized mice received scrambled shRNA or saline. Mice were observed for clinical parameters for 28 days and at termination, anti-MuSK IgG, neuromuscular junction (NMJ) deposits, muscle AChR expression and lymph node B and T cell ratios were assessed by ELISA, immunofluorescence, immunoblotting and flow cytometry, respectively. RESULTS FCRLB shRNA-treated mice showed no muscle weakness or weight loss at termination. Also, they exhibited higher grip strength and muscle AChR levels, lower anti-MuSK IgG and NMJ IgG/C3 levels than control mice. Flow cytometry analysis showed that ratios of major effector lymph node B and T cell populations were not altered by FCRLB silencing. However, regulatory T and CD19 + CD5+ B cell ratios were decreased in FCRLB shRNA-group. CONCLUSION Our results provide evidence regarding involvement and therapeutic value of FCRLB in MuSK-MG. Silencing of FCRLB appears to substantially inhibit antibody production without interfering with survival of major lymphocyte populations.
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Affiliation(s)
- Gizem Koral
- Department of Neuroscience, Aziz Sancar Institute of Experimental Medicine, Istanbul University, Istanbul, Turkey
| | - Canan Ulusoy
- Department of Neuroscience, Aziz Sancar Institute of Experimental Medicine, Istanbul University, Istanbul, Turkey
| | - Judith Cossins
- Neuromuscular Disorders Group, Nuffield Department of Clinical Neurosciences, Weatherall Institute of Molecular Medicine, Oxford, UK
| | | | - Recai Türkoğlu
- Haydarpasa Numune Training and Research Hospital, Istanbul, Turkey
| | - Yin Yao Dong
- Neuromuscular Disorders Group, Nuffield Department of Clinical Neurosciences, Weatherall Institute of Molecular Medicine, Oxford, UK
| | - Erdem Tüzün
- Department of Neuroscience, Aziz Sancar Institute of Experimental Medicine, Istanbul University, Istanbul, Turkey
| | - Vuslat Yılmaz
- Department of Neuroscience, Aziz Sancar Institute of Experimental Medicine, Istanbul University, Istanbul, Turkey.
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26
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Vanoli F, Mantegazza R. Current drug treatment of myasthenia gravis. Curr Opin Neurol 2023; 36:410-415. [PMID: 37678337 DOI: 10.1097/wco.0000000000001196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/09/2023]
Abstract
PURPOSE OF REVIEW Myasthenia Gravis (MG) is a rare neurological disorder affecting the neuromuscular junction. Clinical hallmarks are fatigability and weakness affecting the extraocular, axial, limb and/or respiratory muscles. Despite immunosuppressive treatment, mainly based on corticosteroids and nonsteroidal immunosuppressants, the burden of MG is still significant, both in terms of inadequate disease control and burdensome side effects. Driven by such limits, the past years have been characterized by an escalation of MG drug development, with novel molecules which now focuses on having a more targeted effect, with a higher safety and efficacy profile. RECENT FINDINGS As the pathogenic mechanism of MG are slowly being unravelled, new potential targets for treatments are being considered. This has led since 2017 to the Food and Drug Administration (FDA)-approval of three new drugs that either act by blocking the complement system (i.e., eculizumab and ravulizumab) or by blocking the neonatal Fc receptor thus preventing immunoglobulin recycling and reducing imunoglobulin G (IgG) antibodies (i.e., efgartigimod). Other drugs, with similar mechanism of action, are currently under review for approval. SUMMARY The repertoire of available and developmental therapies for MG is rapidly expanding, finally responding to the unmet need of a more targeted and effective therapeutic approach in MG.
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Affiliation(s)
- Fiammetta Vanoli
- Neuroimmunology and Neuromuscular Disease Department, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan
- Department of Human Neurosciences Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Renato Mantegazza
- Neuroimmunology and Neuromuscular Disease Department, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan
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27
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Rossi L, Santos KBS, Mota BIS, Pimenta J, Oliveira B, Machado CA, Fernandes HB, Barbosa LA, Rodrigues HA, Teixeira GHM, Gomes-Martins GA, Chaimowicz GF, Queiroz-Junior CM, Chaves I, Tapia JC, Teixeira MM, Costa VV, Miranda AS, Guatimosim C. Neuromuscular defects after infection with a beta coronavirus in mice. Neurochem Int 2023; 169:105567. [PMID: 37348761 PMCID: PMC10281698 DOI: 10.1016/j.neuint.2023.105567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 06/14/2023] [Accepted: 06/19/2023] [Indexed: 06/24/2023]
Abstract
COVID-19 affects primarily the lung. However, several other systemic alterations, including muscle weakness, fatigue and myalgia have been reported and may contribute to the disease outcome. We hypothesize that changes in the neuromuscular system may contribute to the latter symptoms observed in COVID-19 patients. Here, we showed that C57BL/6J mice inoculated intranasally with the murine betacoronavirus hepatitis coronavirus 3 (MHV-3), a model for studying COVID-19 in BSL-2 conditions that emulates severe COVID-19, developed robust motor alterations in muscle strength and locomotor activity. The latter changes were accompanied by degeneration and loss of motoneurons that were associated with the presence of virus-like particles inside the motoneuron. At the neuromuscular junction level, there were signs of atrophy and fragmentation in synaptic elements of MHV-3-infected mice. Furthermore, there was muscle atrophy and fiber type switch with alteration in myokines levels in muscles of MHV-3-infected mice. Collectively, our results show that acute infection with a betacoronavirus leads to robust motor impairment accompanied by neuromuscular system alteration.
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Affiliation(s)
- Leonardo Rossi
- Department of Morphology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Kivia B S Santos
- Department of Morphology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Barbara I S Mota
- Department of Morphology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Jordane Pimenta
- Department of Morphology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Bruna Oliveira
- Department of Morphology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Caroline A Machado
- Department of Morphology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Heliana B Fernandes
- Department of Morphology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Leticia A Barbosa
- Department of Morphology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Hermann A Rodrigues
- Departamento de Ciências Básicas da Vida, Universidade Federal de Juiz de Fora, Campus Governador Valadares, MG, Brazil
| | - Gabriel H M Teixeira
- Department of Morphology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Gabriel A Gomes-Martins
- Department of Morphology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Gabriel F Chaimowicz
- Department of Morphology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Celso Martins Queiroz-Junior
- Department of Morphology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Ian Chaves
- Department of Morphology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Juan C Tapia
- School of Medicine, University of Talca, Talca, Chile
| | - Mauro M Teixeira
- Department of Biochemistry, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Vivian V Costa
- Department of Morphology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Aline S Miranda
- Department of Morphology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Cristina Guatimosim
- Department of Morphology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
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28
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Ishihara H, Otani Y, Tanaka K, Miyajima H, Ngo HX, Fujitani M. Blocking insulin-like growth factor 1 receptor signaling pathway inhibits neuromuscular junction regeneration after botulinum toxin-A treatment. Cell Death Dis 2023; 14:609. [PMID: 37717026 PMCID: PMC10505167 DOI: 10.1038/s41419-023-06128-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 08/25/2023] [Accepted: 09/06/2023] [Indexed: 09/18/2023]
Abstract
Botulinum toxin-A (BTX) administration into muscle is an established treatment for conditions with excessive muscle contraction. However, botulinum therapy has short-term effectiveness, and high-dose injection of BTX could induce neutralizing antibodies against BTX. Therefore, prolonging its effects could be beneficial in a clinical situation. Insulin-like growth factor-1 receptor (IGF1R) and its ligands, insulin-like growth factor (IGF) -I and II, regulate the physiological and pathological processes of the nervous system. It has been suggested that IGF1R is involved in the process after BTX administration, but the specific regeneration mechanism remains unclear. Therefore, this study aimed to determine how inhibition of IGF1R signaling pathway affects BTX-induced muscle paralysis. The results showed that anti-IGF1R antibody administration inhibited the recovery from BTX-induced neurogenic paralysis, and the synaptic components at the neuromuscular junction (NMJ), mainly post-synaptic components, were significantly affected by the antibody. In addition, the wet weight or frequency distribution of the cross-sectional area of the muscle fibers was regulated by IGF1R, and sequential antibody administration following BTX treatment increased the number of Pax7+-satellite cells in the gastrocnemius (GC) muscle, independent of NMJ recovery. Moreover, BTX treatment upregulated mammalian target of rapamycin (mTOR)/S6 kinase signaling pathway, HDAC4, Myog, Fbxo32/MAFbx/Atrogin-1 pathway, and transcription of synaptic components, but not autophagy. Finally, IGF1R inhibition affected only mTOR/S6 kinase translational signaling in the GC muscle. In conclusion, the IGF1R signaling pathway is critical for NMJ regeneration via specific translational signals. IGF1R inhibition could be highly beneficial in clinical practice by decreasing the number of injections and total dose of BTX due to the prolonged duration of the effect.
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Affiliation(s)
- Hiroki Ishihara
- Department of Anatomy and Neuroscience, Faculty of Medicine, Shimane University, 89-1 Enya-cho, Izumo-shi, Shimane, 693-8501, Japan
- Department of Rehabilitation, Faculty of Medicine, Shimane University, 89-1 Enya-cho, Izumo-shi, Shimane, 693-8501, Japan
| | - Yoshinori Otani
- Department of Anatomy and Neuroscience, Faculty of Medicine, Shimane University, 89-1 Enya-cho, Izumo-shi, Shimane, 693-8501, Japan
| | - Kazuki Tanaka
- Department of Anatomy and Neuroscience, Faculty of Medicine, Shimane University, 89-1 Enya-cho, Izumo-shi, Shimane, 693-8501, Japan
- Department of Rehabilitation, Faculty of Medicine, Shimane University, 89-1 Enya-cho, Izumo-shi, Shimane, 693-8501, Japan
| | - Hisao Miyajima
- Department of Anatomy and Neuroscience, Faculty of Medicine, Shimane University, 89-1 Enya-cho, Izumo-shi, Shimane, 693-8501, Japan
| | - Huy Xuan Ngo
- Department of Anatomy and Neuroscience, Faculty of Medicine, Shimane University, 89-1 Enya-cho, Izumo-shi, Shimane, 693-8501, Japan
- Department of Oral and Maxillofacial Surgery, Faculty of Medicine, Shimane University, 89-1 Enya-cho, Izumo-shi, Shimane, 693-8501, Japan
| | - Masashi Fujitani
- Department of Anatomy and Neuroscience, Faculty of Medicine, Shimane University, 89-1 Enya-cho, Izumo-shi, Shimane, 693-8501, Japan.
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29
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Hossain MS, Yao A, Qiao X, Shi W, Xie T, Chen C, Zhang YQ. Gbb glutathionylation promotes its proteasome-mediated degradation to inhibit synapse growth. J Cell Biol 2023; 222:e202202068. [PMID: 37389657 PMCID: PMC10316630 DOI: 10.1083/jcb.202202068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 04/20/2023] [Accepted: 06/13/2023] [Indexed: 07/01/2023] Open
Abstract
Glutathionylation is a posttranslational modification involved in various molecular and cellular processes. However, it remains unknown whether and how glutathionylation regulates nervous system development. To identify critical regulators of synapse growth and development, we performed an RNAi screen and found that postsynaptic knockdown of glutathione transferase omega 1 (GstO1) caused significantly more synaptic boutons at the Drosophila neuromuscular junctions. Genetic and biochemical analysis revealed an increased level of glass boat bottom (Gbb), the Drosophila homolog of mammalian bone morphogenetic protein (BMP), in GstO1 mutants. Further experiments showed that GstO1 is a critical regulator of Gbb glutathionylation at cysteines 354 and 420, which promoted its degradation via the proteasome pathway. Moreover, the E3 ligase Ctrip negatively regulated the Gbb protein level by preferentially binding to glutathionylated Gbb. These results unveil a novel regulatory mechanism in which glutathionylation of Gbb facilitates its ubiquitin-mediated degradation. Taken together, our findings shed new light on the crosstalk between glutathionylation and ubiquitination of Gbb in synapse development.
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Affiliation(s)
- Md Shafayat Hossain
- Key Laboratory of Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Aiyu Yao
- Key Laboratory of Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Xinhua Qiao
- Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Wenwen Shi
- Key Laboratory of Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Ting Xie
- Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Chang Chen
- Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yong Q. Zhang
- Key Laboratory of Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
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30
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Li Y, Patel M, Baroudi J, Wu M, Gatti S, Liang M, Wipf P, Badawi Y, Meriney SD. A cross-sectional study of ageing at the mouse neuromuscular junction and effects of an experimental therapeutic approach for dynapenia. J Physiol 2023; 601:4135-4150. [PMID: 37606613 DOI: 10.1113/jp284749] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Accepted: 08/08/2023] [Indexed: 08/23/2023] Open
Abstract
Despite prior efforts to understand and target dynapenia (age-induced loss of muscle strength), this condition remains a major challenge that reduces the quality of life in the aged population. We have focused on the neuromuscular junction (NMJ) where changes in structure and function have rarely been systematically studied as a dynamic and progressive process. Our cross-sectional study found neurotransmission at the male mouse NMJ to be biphasic, displaying an early increase followed by a later decrease, and this phenotype was associated with structural changes to the NMJ. A cross-sectional characterization showed that age-induced alterations fell into four age groups: young adult (3-6 months), adult (7-18 months), early aged (19-24 months), and later aged (25-30 months). We then utilized a small molecule therapeutic candidate, GV-58, applied acutely during the later aged stage to combat age-induced reductions in transmitter release by increasing calcium influx during an action potential, which resulted in a significant increase in transmitter release. This comprehensive study of neuromuscular ageing at the NMJ will enable future research to target critical time points for therapeutic intervention. KEY POINTS: Age-induced frailty and falls are the leading causes of injury-related death and are caused by an age-induced loss of muscle strength due to a combination of neurological and muscular changes. A cross-sectional approach was used to study age-induced changes to the neuromuscular junction in a mouse model, and physiological changes that were biphasic over the ageing time course were found. Changes in physiology at the neuromuscular junction were correlated with alterations in neuromuscular junction morphology. An acutely applied positive allosteric gating modifier of presynaptic voltage-gated calcium channels was tested as a candidate therapeutic strategy that could increase transmitter release at aged neuromuscular junctions. These results provide a detailed time course of age-induced changes at the neuromuscular junction in a mouse model and test a candidate therapeutic strategy for weakness.
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Affiliation(s)
- Y Li
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA
| | - M Patel
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA
| | - J Baroudi
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA
| | - M Wu
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA
| | - S Gatti
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA
| | - M Liang
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, USA
| | - P Wipf
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, USA
| | - Y Badawi
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA
| | - Stephen D Meriney
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA
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31
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Badu-Mensah A, Guo X, Mendez R, Parsaud H, Hickman JJ. The Effect of Skeletal Muscle-Specific Creatine Treatment on ALS NMJ Integrity and Function. Int J Mol Sci 2023; 24:13519. [PMID: 37686322 PMCID: PMC10487911 DOI: 10.3390/ijms241713519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 08/16/2023] [Accepted: 08/19/2023] [Indexed: 09/10/2023] Open
Abstract
Although skeletal muscle (hSKM) has been proven to be actively involved in Amyotrophic Lateral Sclerosis (ALS) neuromuscular junction (NMJ) dysfunction, it is rarely considered as a pharmacological target in preclinical drug discovery. This project investigated how improving ALS hSKM viability and function effects NMJ integrity. Phenotypic ALS NMJ human-on-a-chip models developed from patient-derived induced pluripotent stem cells (iPSCs) were used to study the effect of hSKM-specific creatine treatment on clinically relevant functional ALS NMJ parameters, such as NMJ numbers, fidelity, stability, and fatigue index. Results indicated comparatively enhanced NMJ numbers, fidelity, and stability, as well as reduced fatigue index, across all hSKM-specific creatine-treated systems. Immunocytochemical analysis of the NMJs also revealed improved post-synaptic nicotinic Acetylcholine receptor (AChR) clustering and cluster size in systems supplemented with creatine relative to the un-dosed control. This work strongly suggests hSKM as a therapeutic target in ALS drug discovery. It also demonstrates the need to consider all tissues involved in multi-systemic diseases, such as ALS, in drug discovery efforts. Finally, this work further establishes the BioMEMs NMJ platform as an effective means of performing mutation-specific drug screening, which is a step towards personalized medicine for rare diseases.
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Affiliation(s)
- Agnes Badu-Mensah
- NanoScience Technology Center, University of Central Florida, 12424 Research Parkway, Suite 400, Orlando, FL 32826, USA; (A.B.-M.); (X.G.); (R.M.); (H.P.)
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32816, USA
| | - Xiufang Guo
- NanoScience Technology Center, University of Central Florida, 12424 Research Parkway, Suite 400, Orlando, FL 32826, USA; (A.B.-M.); (X.G.); (R.M.); (H.P.)
| | - Roxana Mendez
- NanoScience Technology Center, University of Central Florida, 12424 Research Parkway, Suite 400, Orlando, FL 32826, USA; (A.B.-M.); (X.G.); (R.M.); (H.P.)
| | - Hemant Parsaud
- NanoScience Technology Center, University of Central Florida, 12424 Research Parkway, Suite 400, Orlando, FL 32826, USA; (A.B.-M.); (X.G.); (R.M.); (H.P.)
| | - James J. Hickman
- NanoScience Technology Center, University of Central Florida, 12424 Research Parkway, Suite 400, Orlando, FL 32826, USA; (A.B.-M.); (X.G.); (R.M.); (H.P.)
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32816, USA
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Dunn E, Steinert JR, Stone A, Sahota V, Williams RSB, Snowden S, Augustin H. Medium-Chain Fatty Acids Rescue Motor Function and Neuromuscular Junction Degeneration in a Drosophila Model of Amyotrophic Lateral Sclerosis. Cells 2023; 12:2163. [PMID: 37681895 PMCID: PMC10486503 DOI: 10.3390/cells12172163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 08/21/2023] [Accepted: 08/22/2023] [Indexed: 09/09/2023] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is an adult-onset neurodegenerative disease characterised by progressive degeneration of the motor neurones. An expanded GGGGCC (G4C2) hexanucleotide repeat in C9orf72 is the most common genetic cause of ALS and frontotemporal dementia (FTD); therefore, the resulting disease is known as C9ALS/FTD. Here, we employ a Drosophila melanogaster model of C9ALS/FTD (C9 model) to investigate a role for specific medium-chain fatty acids (MCFAs) in reversing pathogenic outcomes. Drosophila larvae overexpressing the ALS-associated dipeptide repeats (DPRs) in the nervous system exhibit reduced motor function and neuromuscular junction (NMJ) defects. We show that two MCFAs, nonanoic acid (NA) and 4-methyloctanoic acid (4-MOA), can ameliorate impaired motor function in C9 larvae and improve NMJ degeneration, although their mechanisms of action are not identical. NA modified postsynaptic glutamate receptor density, whereas 4-MOA restored defects in the presynaptic vesicular release. We also demonstrate the effects of NA and 4-MOA on metabolism in C9 larvae and implicate various metabolic pathways as dysregulated in our ALS model. Our findings pave the way to identifying novel therapeutic targets and potential treatments for ALS.
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Affiliation(s)
- Ella Dunn
- Centre for Biomedical Sciences, Department of Biological Sciences, Royal Holloway University of London, Egham, Surrey TW20 OEX, UK; (E.D.); (R.S.B.W.)
| | - Joern R. Steinert
- Faculty of Medicine & Health Sciences, Queen’s Medical Centre, Nottingham NG7 2UH, UK; (J.R.S.); (A.S.)
| | - Aelfwin Stone
- Faculty of Medicine & Health Sciences, Queen’s Medical Centre, Nottingham NG7 2UH, UK; (J.R.S.); (A.S.)
| | - Virender Sahota
- Centre for Biomedical Sciences, Department of Biological Sciences, Royal Holloway University of London, Egham, Surrey TW20 OEX, UK; (E.D.); (R.S.B.W.)
| | - Robin S. B. Williams
- Centre for Biomedical Sciences, Department of Biological Sciences, Royal Holloway University of London, Egham, Surrey TW20 OEX, UK; (E.D.); (R.S.B.W.)
| | - Stuart Snowden
- Centre for Biomedical Sciences, Department of Biological Sciences, Royal Holloway University of London, Egham, Surrey TW20 OEX, UK; (E.D.); (R.S.B.W.)
| | - Hrvoje Augustin
- Centre for Biomedical Sciences, Department of Biological Sciences, Royal Holloway University of London, Egham, Surrey TW20 OEX, UK; (E.D.); (R.S.B.W.)
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Iyadurai S, Geller T, Wyrebek R, Crenshaw M, Brooks S, DiBartolomeo M, Mroczek M. PURA syndrome: Neuromuscular junction manifestations with potential therapeutic implications. Neuromuscul Disord 2023; 33:699. [PMID: 36631330 DOI: 10.1016/j.nmd.2022.11.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 11/02/2022] [Accepted: 11/03/2022] [Indexed: 11/06/2022]
Affiliation(s)
- Stanley Iyadurai
- Johns Hopkins All Children's Hospital, St. Petersburg, FL 33701, USA.
| | - Thomas Geller
- Johns Hopkins All Children's Hospital, St. Petersburg, FL 33701, USA
| | - Rita Wyrebek
- Cardinal Glennon Children's Hospital, Saint Louis University, St. Louis, MO 63103, USA
| | - Melissa Crenshaw
- Johns Hopkins All Children's Hospital, St. Petersburg, FL 33701, USA
| | - Sandra Brooks
- Johns Hopkins All Children's Hospital, St. Petersburg, FL 33701, USA
| | - Mara DiBartolomeo
- Johns Hopkins All Children's Hospital, St. Petersburg, FL 33701, USA
| | - Magdalena Mroczek
- Center for Cardiovascular Genetics & Gene Diagnostics, Foundation for People with Rare Diseases, Schlieren-Zurich 8952, Switzerland.
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Clark BC. Neural Mechanisms of Age-Related Loss of Muscle Performance and Physical Function. J Gerontol A Biol Sci Med Sci 2023; 78:8-13. [PMID: 36738253 PMCID: PMC10272985 DOI: 10.1093/gerona/glad029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND This article discusses the putative neural mechanisms of age-related muscle weakness within the broader context of the development of function-promoting therapies for sarcopenia and age-related mobility limitations. We discuss here the evolving definition of sarcopenia and its primary defining characteristic, weakness. METHODS This review explores the premise that impairments in the nervous system's ability to generate maximal force or power contribute to sarcopenia. RESULTS Impairments in neural activation are responsible for a substantial amount of age-related weakness. The neurophysiological mechanisms of weakness are multifactorial. The roles of supraspinal descending command mechanisms, spinal motor neuron firing responsivity, and neuromuscular junction transmission failure in sarcopenia are discussed. Research/clinical gaps and recommendations for future work are highlighted. CONCLUSION Further research is needed to map putative neural mechanisms, determine the clinical relevance of age-related changes in neural activation to sarcopenia, and evaluate the effectiveness of various neurotherapeutic approaches to enhancing physical function.
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Affiliation(s)
- Brian C Clark
- Ohio Musculoskeletal and Neurological Institute (OMNI) and the Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, Ohio, USA
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Paul TA, Macpherson PC, Janetzke TL, Davis CS, Jackson MJ, McArdle A, Brooks SV. Older mice show decreased regeneration of neuromuscular junctions following lengthening contraction-induced injury. GeroScience 2023; 45:1899-1912. [PMID: 36952126 PMCID: PMC10400502 DOI: 10.1007/s11357-023-00774-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Accepted: 03/13/2023] [Indexed: 03/24/2023] Open
Abstract
Progressive muscle atrophy and loss of muscle strength associated with old age have been well documented. Although age-associated impairments in skeletal muscle regeneration following injury have been demonstrated, less is known about whether aging impacts the regenerative response of neuromuscular junctions (NMJ) following contraction-induced injury. Reduced ability of NMJs to regenerate could lead to increased numbers of denervated muscle fibers and therefore play a contributing role to age-related sarcopenia. To investigate the relationship between age and NMJ regeneration following injury, extensor digitorum longus (EDL) muscles of middle-aged (18-19 months) and old mice (27-28 months) were subjected to a protocol of lengthening contractions (LC) that resulted in an acute force deficit of ~55% as well as functional and histological evidence of a similar magnitude of injury 3 days post LCs that was not different between age groups. After 28 days, the architecture and innervation of the NMJs were evaluated. The numbers of fragmented endplates increased and of fully innervated NMJs decreased post-injury for the muscle of both middle-aged and old mice and for contralateral uninjured muscles of old compared with uninjured muscles of middle-aged controls. Thus, the diminished ability of the skeletal muscle of old mice to recover following injury may be due in part to an age-related decrease in the ability to regenerate NMJs in injured muscles. The impaired ability to regenerate NMJs may be a triggering factor for degenerative changes at the NMJ contributing to muscle fiber weakness and loss in old age.
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Affiliation(s)
- Thomas A. Paul
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI USA
- Department of Biomedical Engineering, University of Michigan, 2029 Biomedical Sciences Building, 109 Zina Pitcher Place, Ann Arbor, MI 48109-2200 USA
| | - Peter C. Macpherson
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI USA
| | - Tara L. Janetzke
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI USA
| | - Carol S. Davis
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI USA
| | - Malcolm J. Jackson
- MRC-Versus Arthritis Centre for Integrated Research into Musculoskeletal Ageing (CIMA), Institute of Life Course and Ageing Science, University of Liverpool, Liverpool, UK
| | - Anne McArdle
- MRC-Versus Arthritis Centre for Integrated Research into Musculoskeletal Ageing (CIMA), Institute of Life Course and Ageing Science, University of Liverpool, Liverpool, UK
| | - Susan V. Brooks
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI USA
- Department of Biomedical Engineering, University of Michigan, 2029 Biomedical Sciences Building, 109 Zina Pitcher Place, Ann Arbor, MI 48109-2200 USA
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36
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Cheli M, Brugnoni R, Gibertini S, Mantegazza R, Maggi L. Novel DPAGT1 Gene Mutation in Two Twins with Congenital Myasthenic Syndrome and a Review of the Literature. J Neuromuscul Dis 2023; 10:449-458. [PMID: 37005892 DOI: 10.3233/jnd-221675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/30/2023]
Abstract
Congenital myasthenic syndromes (CMS) are rare diseases caused by mutation in genes coding for proteins involved in neuromuscular junction structure and function. DPAGT1 gene mutations are a rare cause of CMS whose clinical evolution and pathophysiological mechanisms have not been clarified completely. We present the case of two twins displaying an infancy-onset predominant limb-girdle phenotype and carrying a novel DPAGT1 mutation associated with unusual histological and clinical findings. CMS can mimic paediatric and adult limb-girdle phenotype, hence neurophysiology plays a fundamental role in the differential diagnosis.
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Affiliation(s)
- Marta Cheli
- Neuroimmunology and Neuromuscular Disease Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy
| | - Raffaella Brugnoni
- Neuroimmunology and Neuromuscular Disease Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy
| | - Sara Gibertini
- Neuroimmunology and Neuromuscular Disease Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy
| | - Renato Mantegazza
- Neuroimmunology and Neuromuscular Disease Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy
| | - Lorenzo Maggi
- Neuroimmunology and Neuromuscular Disease Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy
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Arpke RW, Moritz TC, Hahn KL, Stark DA, Villalón E, Lorson CL, Cornelison DDW. Normal muscle fiber type distribution is recapitulated in aged ephrin-A3 -/- mice that previously lacked most slow myofibers. Am J Physiol Cell Physiol 2023; 324:C718-C727. [PMID: 36717102 PMCID: PMC10027087 DOI: 10.1152/ajpcell.00519.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 01/18/2023] [Accepted: 01/19/2023] [Indexed: 02/01/2023]
Abstract
Individual limb muscles have characteristic representation and spatial distribution of muscle fiber types (one slow and up to three fast isoforms) appropriate to their unique anatomical location and function. This distribution can be altered by physiological stimuli such as training (i.e., for increased endurance or force) or pathological conditions such as aging. Our group previously showed that ephrin-A3 is expressed only on slow myofibers, and that adult mice lacking ephrin-A3 have dramatically reduced numbers of slow myofibers due to postnatal innervation of previously slow myofibers by fast motor neurons. In this study, fiber type composition of hindlimb muscles of aged and denervated/reinnervated C57BL/6 and ephrin-A3-/- mice was analyzed to determine whether the loss of slow myofibers persists across the lifespan. Surprisingly, fiber-type composition of ephrin-A3-/- mouse muscles at two years of age was nearly indistinguishable from age-matched C57BL/6 mice. After challenge with nerve crush, the percentage of IIa and I/IIa hybrid myofibers increased significantly in aged ephrin-A3-/- mice. While EphA8, the receptor for ephrin-A3, is present at all neuromuscular junctions (NMJs) on fast fibers in 3-6 mo old C57BL/6 and ephrin-A3-/- mice, this exclusive localization is lost with aging, with EphA8 expression now found on a subset of NMJs on some slow muscle fibers. This return to appropriate fiber-type distribution given time and under use reinforces the role of activity in determining fiber-type representation and suggests that, rather than being a passive baseline, the developmentally and evolutionarily selected fiber type pattern may instead be actively reinforced by daily living.
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Affiliation(s)
- Robert W. Arpke
- Division of Biological Sciences, University of Missouri, Columbia, Missouri, United States
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, Missouri, United States
| | - Timothy C. Moritz
- Division of Biological Sciences, University of Missouri, Columbia, Missouri, United States
| | - Kevin L. Hahn
- Division of Biological Sciences, University of Missouri, Columbia, Missouri, United States
| | - Danny A. Stark
- Division of Biological Sciences, University of Missouri, Columbia, Missouri, United States
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, Missouri, United States
| | - Eric Villalón
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, Missouri, United States
| | - Christian L. Lorson
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, Missouri, United States
| | - DDW Cornelison
- Division of Biological Sciences, University of Missouri, Columbia, Missouri, United States
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, Missouri, United States
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38
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Smuder AJ, Levine S, Powers SK. Critical Illness Myopathy Alters Diaphragm Neuromuscular Junction Protein and Gene Expression. Am J Respir Crit Care Med 2023; 207:358-361. [PMID: 36264747 PMCID: PMC9896635 DOI: 10.1164/rccm.202204-0683le] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
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39
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Mroczek M, Iyadurai S. Neuromuscular and Neuromuscular Junction Manifestations of the PURA-NDD: A Systematic Review of the Reported Symptoms and Potential Treatment Options. Int J Mol Sci 2023; 24:ijms24032260. [PMID: 36768582 PMCID: PMC9917016 DOI: 10.3390/ijms24032260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 01/14/2023] [Accepted: 01/20/2023] [Indexed: 01/26/2023] Open
Abstract
PURA-related neurodevelopmental disorders (PURA-NDDs) are a rare genetic disease caused by pathogenic autosomal dominant variants in the PURA gene or a deletion encompassing the PURA gene. PURA-NDD is clinically characterized by neurodevelopmental delay, learning disability, neonatal hypotonia, feeding difficulties, abnormal movements, and epilepsy. It is generally considered to be central nervous system disorders, with generalized weakness, associated hypotonia, cognitive and development deficits in early development, and seizures in late stages. Although it is classified predominantly as a central nervous syndrome disorder, some phenotypic features, such as myopathic facies, respiratory insufficiency of muscle origin, and myopathic features on muscle biopsy and electrodiagnostic evaluation, point to a peripheral (neuromuscular) source of weakness. Patients with PURA-NDD have been increasingly identified in exome-sequenced cohorts of patients with neuromuscular- and congenital myasthenic syndrome-like phenotypes. Recently, fluctuating weakness noted in a PURA-NDD patient, accompanied by repetitive nerve stimulation abnormalities, suggested the disease to be a channelopathy and, more specifically, a neuromuscular junction disorder. Treatment with pyridostigmine or salbutamol led to clinical improvement of neuromuscular function in two reported cases. The goal of this systematic retrospective review is to highlight the motor symptoms of PURA-NDD, to further describe the neuromuscular phenotype, and to emphasize the role of potential treatment opportunities of the neuromuscular phenotype in the setting of the potential role of PURA protein in the neuromuscular junction and the muscles.
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Affiliation(s)
- Magdalena Mroczek
- Center for Cardiovascular Genetics & Gene Diagnostics, Foundation for People with Rare Diseases, 8952 Schlieren, Switzerland
- Correspondence: (M.M.); (S.I.)
| | - Stanley Iyadurai
- Division of Neurology, Johns Hopkins All Children’s Hospital, 501 6th Ave S, St. Petersburg, FL 33701, USA
- Correspondence: (M.M.); (S.I.)
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40
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Bromberg MB. Quantitative electrodiagnosis of the motor unit. Handb Clin Neurol 2023; 195:271-286. [PMID: 37562872 DOI: 10.1016/b978-0-323-98818-6.00016-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/12/2023]
Abstract
Electromyography (EMG) focuses on assessment of the motor unit (MU), and a given muscle has several hundred MUs, each innervating hundreds of muscle fibers. Assessment is limited by the recording radius of electrodes, 1-2 fibers with single-fiber electrodes and 7-15 fibers with concentric or monopolar electrodes. Routine qualitative EMG studies rely on observing MUs in free-run mode and qualitatively estimating common metrics. In contrast, quantitative EMG (QEMG) applied to routine studies includes assessment of individual MUs by software available in modern EMG machines with extraction of discrete values for common metrics, and also derived metrics. This results in greater precision and statistical interpretation. Other QEMG techniques assess muscle fiber density within the MU and time variability at the neuromuscular junction. The interference pattern can also be assessed. The number of MUs innervating a muscle can be estimated. Advanced signal processing, called near-fiber EMG, allows for extraction of underlying muscle fiber contributions to MU waveforms. It is also possible to use QEMG to make statistical probabilities of the state of a muscle as to whether normal, myopathic, or neuropathic. Time to acquire QEMG data is minimal. QEMG is most useful in situations where pathology is uncertain.
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Affiliation(s)
- Mark B Bromberg
- Department of Neurology, University of Utah, Salt Lake City, UT, United States.
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41
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Vacassenno RM, Haddad CN, Cooper RL. The effects of doxapram (blocker of K2p channels) on resting membrane potential and synaptic transmission at the Drosophila neuromuscular junction. Comp Biochem Physiol C Toxicol Pharmacol 2023; 263:109497. [PMID: 36306997 DOI: 10.1016/j.cbpc.2022.109497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 09/26/2022] [Accepted: 10/23/2022] [Indexed: 11/03/2022]
Abstract
The resting membrane potential of most cells is maintained by potassium K2p channels. The pharmacological profile and distribution of various K2p channel subtypes in organisms are still being investigated. The Drosophila genome contains 11 subtypes; however, their function and expression profiles have not yet been determined. Doxapram is clinically used to enhance respiration in humans and blocks the acid-sensitive K2p TASK subtype in mammals. The resting membrane potential of larval Drosophila muscle and synaptic transmission at the neuromuscular junction are pH sensitive. The present study investigated the effects of doxapram on membrane potential and synaptic transmission using intracellular recordings of larval Drosophila muscles. Doxapram (1 mM and 10 mM) depolarizes the muscle and appears to depolarize motor neurons, causing an increase in the frequency of spontaneous quantal events and evoked excitatory junction potentials. Verapamil (1 and 10 mM) paralleled the action of doxapram. These changes were matched by an extracellular increase in KCl (50 mM) and blocked by Cd2+. It is assumed that the motor nerve depolarizes to open voltage-gated Ca2+ channels in presynaptic nerve terminals because of exposure to doxapram. These findings are significant for building models to better understand the function of pharmacological agents that affect K2p channels and how K2p channels contribute to the physiology of tissues. Drosophila offers a genetically amenable model that can alter the tissue-specific expression of K2p channel subtypes to simulate known human diseases related to this family of channels.
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Affiliation(s)
- Rachael M Vacassenno
- Department of Biology, University of Kentucky, Lexington, KY 40506-0225, USA; Department of Biology, Eastern Kentucky University, Richmond, KY 40475, USA.
| | - Christine N Haddad
- Department of Biology, University of Kentucky, Lexington, KY 40506-0225, USA.
| | - Robin L Cooper
- Department of Biology, University of Kentucky, Lexington, KY 40506-0225, USA.
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Tolsma R, Pan H, Harris L, Spitsbergen JM, Li Y. Hypoxia-induced reprogrammed myoblasts enhance the formation of neuromuscular junctions: A pioneer study. J Cell Biochem 2022; 123:2057-2065. [PMID: 36208481 DOI: 10.1002/jcb.30334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 08/31/2022] [Accepted: 09/15/2022] [Indexed: 12/24/2022]
Abstract
We previously reported that muscle cells could reprogram into progenitors after traumatic injuries. These injury-induced muscle stem cells (iMuSCs) have increased migration and differentiation capacities, including neuronal differentiation. Recent studies in our laboratory suggest that the hypoxia-induced by tissue injury plays an essential role in the reprogramming process of muscle cells. We hypothesize that muscle cells reprogrammed with hypoxia have increased neuronal differentiation potentials and the neuronal differentiation extends into the formation of neuromuscular junction (NMJ)-like structures. In this study, C2C12 myoblasts were cultured under hypoxic conditions and subsequently in neural differentiation media to generate neurospheres, and then with muscle differentiation media to induce NMJ-like structure formation. Hypoxia-induced muscle cells also produced more robust NMJs compared to controls after intramuscular cell transplantation. Our results suggest hypoxia plays a role in the reprogramming of muscle stem cells, which may have the potential to form neuromuscular junctions and ultimately contribute to functional muscle healing.
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Affiliation(s)
- Rachael Tolsma
- Western Michigan University Homer Stryker MD School of Medicine, Kalamazoo, Michigan, USA
| | - Haiying Pan
- Department of Orthopaedic Surgery, Biomedical Engineering, Western Michigan University Homer Stryker MD School of Medicine, Kalamazoo, Michigan, USA
| | - Loyall Harris
- Western Michigan University Homer Stryker MD School of Medicine, Kalamazoo, Michigan, USA
| | - John M Spitsbergen
- Department of Biological Sciences, Western Michigan University, Kalamazoo, Michigan, USA
| | - Yong Li
- Department of Orthopaedic Surgery, Biomedical Engineering, Western Michigan University Homer Stryker MD School of Medicine, Kalamazoo, Michigan, USA
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Volpe P, Bosutti A, Nori A, Filadi R, Gherardi G, Trautmann G, Furlan S, Massaria G, Sciancalepore M, Megighian A, Caccin P, Bernareggi A, Salanova M, Sacchetto R, Sandonà D, Pizzo P, Lorenzon P. Nerve-dependent distribution of subsynaptic type 1 inositol 1,4,5-trisphosphate receptor at the neuromuscular junction. J Gen Physiol 2022; 154:213498. [PMID: 36149386 PMCID: PMC9513380 DOI: 10.1085/jgp.202213128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2022] [Revised: 08/30/2022] [Accepted: 09/09/2022] [Indexed: 11/20/2022] Open
Abstract
Inositol 1,4,5-trisphosphate receptors (IP3Rs) are enriched at postsynaptic membrane compartments of the neuromuscular junction (NMJ), surrounding the subsynaptic nuclei and close to nicotinic acetylcholine receptors (nAChRs) of the motor endplate. At the endplate level, it has been proposed that nerve-dependent electrical activity might trigger IP3-associated, local Ca2+ signals not only involved in excitation-transcription (ET) coupling but also crucial to the development and stabilization of the NMJ itself. The present study was undertaken to examine whether denervation affects the subsynaptic IP3R distribution in skeletal muscles and which are the underlying mechanisms. Fluorescence microscopy, carried out on in vivo denervated muscles (following sciatectomy) and in vitro denervated skeletal muscle fibers from flexor digitorum brevis (FDB), indicates that denervation causes a reduction in the subsynaptic IP3R1-stained region, and such a decrease appears to be determined by the lack of muscle electrical activity, as judged by partial reversal upon field electrical stimulation of in vitro denervated skeletal muscle fibers.
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Affiliation(s)
- Pompeo Volpe
- Department of Biomedical Sciences and Interdepartmental Research Center of Myology (cirMYO), University of Padova, Padova, Italy
- Correspondence to Pompeo Volpe:
| | | | - Alessandra Nori
- Department of Biomedical Sciences and Interdepartmental Research Center of Myology (cirMYO), University of Padova, Padova, Italy
| | - Riccardo Filadi
- Department of Biomedical Sciences and Interdepartmental Research Center of Myology (cirMYO), University of Padova, Padova, Italy
- National Research Council, Neuroscience Institute, Padova, Italy
| | - Gaia Gherardi
- Department of Biomedical Sciences and Interdepartmental Research Center of Myology (cirMYO), University of Padova, Padova, Italy
| | - Gabor Trautmann
- Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Institute of Integrative Neuroanatomy, Berlin, Germany
| | - Sandra Furlan
- National Research Council, Neuroscience Institute, Padova, Italy
| | | | | | - Aram Megighian
- Department of Biomedical Sciences and Interdepartmental Research Center of Myology (cirMYO), University of Padova, Padova, Italy
| | - Paola Caccin
- Department of Biomedical Sciences and Interdepartmental Research Center of Myology (cirMYO), University of Padova, Padova, Italy
| | | | - Michele Salanova
- Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Institute of Integrative Neuroanatomy, Berlin, Germany
- Neuromuscular Signaling, Center of Space Medicine Berlin, Berlin, Germany
| | - Roberta Sacchetto
- Department of Comparative Biomedicine and Food Science, University of Padova, Padova, Italy
| | - Dorianna Sandonà
- Department of Biomedical Sciences and Interdepartmental Research Center of Myology (cirMYO), University of Padova, Padova, Italy
| | - Paola Pizzo
- Department of Biomedical Sciences and Interdepartmental Research Center of Myology (cirMYO), University of Padova, Padova, Italy
- National Research Council, Neuroscience Institute, Padova, Italy
| | - Paola Lorenzon
- Department of Life Sciences, University of Trieste, Trieste, Italy
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Wu JW, Yan YH, Chien TW, Chou W. Trend and prediction of citations on the topic of neuromuscular junctions in 100 top-cited articles since 2001 using a temporal bar graph: A bibliometric analysis. Medicine (Baltimore) 2022; 101:e30674. [PMID: 36221404 PMCID: PMC9542577 DOI: 10.1097/md.0000000000030674] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND A neuromuscular junction (NMJ) (or myoneural junction) is a chemical synapse between a motor neuron (MN) and a muscle fiber. Although numerous articles have been published, no such analyses on trend or prediction of citations in NMJ were characterized using the temporal bar graph (TBG). This study is to identify the most dominant entities in the 100 top-cited articles in NMJ (T100MNJ for short) since 2001; to verify the improved TBG that is viable for trend analysis; and to investigate whether medical subject headings (MeSH terms) can be used to predict article citations. METHODS We downloaded T100MNJ from the PubMed database by searching the string ("NMJ" [MeSH Major Topic] AND ("2001" [Date - Modification]: "2021" [Date - Modification])) and matching citations to each article. Cluster analysis of citations was performed to select the most cited entities (e.g., authors, research institutes, affiliated countries, journals, and MeSH terms) in T100MNJ using social network analysis. The trend analysis was displayed using TBG with two major features of burst spot and trend development. Next, we examined the MeSH prediction effect on article citations using its correlation coefficients (CC) when the mean citations in MeSH terms were collected in 100 top-cited articles related to NMJ (T100NMJs). RESULTS The most dominant entities (i.e., country, journal, MesH term, and article in T100NMJ) in citations were the US (with impact factor [IF] = 142.2 = 10237/72), neuron (with IF = 151.3 = 3630/24), metabolism (with IF = 133.02), and article authored by Wagh et al from Germany in 2006 (with 342 citing articles). The improved TBG was demonstrated to highlight the citation evolution using burst spots, trend development, and line-chart plots. MeSH terms were evident in the prediction power on the number of article citations (CC = 0.40, t = 4.34). CONCLUSION Two major breakthroughs were made by developing the improved TBG applied to bibliographical studies and the prediction of article citations using the impact factor of MeSH terms in T100NMJ. These visualizations of improved TBG and scatter plots in trend, and prediction analyses are recommended for future academic pursuits and applications in other disciplines.
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Affiliation(s)
- Jian-Wei Wu
- Department of Physical Medicine and Rehabilitation, Taipei Medical University Hospital, Taipei, Taiwan
| | - Yu-Hua Yan
- Superintendent Office, Tainan Municipal Hospital (Managed by Show Chwan Medical Care Corporation), Tainan, Taiwan
- Department of Health Care Administration, Chia Nan University of Pharmacy and Science, Tainan, Taiwan
| | - Tsair-Wei Chien
- Medical Research Department, Chi-Mei Medical Center, Tainan, Taiwan
| | - Willy Chou
- Department of Physical Medicine and Rehabilitation, Chi Mei Medical Center, Tainan, Taiwan
- Department of Physical Medicine and Rehabilitation, Chung San Medical University Hospital, Taichung, Taiwan
- *Correspondence: Tsair-Wei Chien, Department of Physical Medicine and Rehabilitation, Chi Mei Medical Center, 901 Chung Hwa Road, Yung Kung District, Tainan 710, Taiwan (e-mail: )
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Qashqari H, McNiven V, Gonorazky H, Mendoza-Londono R, Hassan A, Kulkarni T, Amburgey K, Dowling JJ. PURA syndrome: neuromuscular junction manifestations with potential therapeutic implications. Neuromuscul Disord 2022; 32:842-844. [PMID: 36210261 DOI: 10.1016/j.nmd.2022.09.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 08/30/2022] [Accepted: 09/21/2022] [Indexed: 11/26/2022]
Abstract
PURA syndrome is caused by heterozygous de novo pathogenic variants in PURA. It is characterized by moderate to severe neurodevelopmental disability with a wide clinical spectrum and an evolving phenotype. We present two individuals with genetically confirmed PURA syndrome who had severe neonatal signs and symptoms and a novel phenotype suggestive of neuromuscular junction pathology. We demonstrate that PURA syndrome shares features consistent with a congenital myasthenic syndrome; we thus recommend electrodiagnostic study in neonates and infants with PURA syndrome, and consideration of salbutamol as a therapeutic option.
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Affiliation(s)
- Hebah Qashqari
- Division of Neurology, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, 555 University Avenue, Toronto, ON M5G 1X8, Canada; Department of Pediatrics, King Faisal Specialist Hospital & Research Centre, Jeddah, Saudi Arabia
| | - Vanda McNiven
- Division of Clinical and Metabolic Genetics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada; Fred A Litwin Family Centre in Genetic Medicine, University Health Network and Mount Sinai Hospital, Toronto, Ontario, Canada
| | - Hernan Gonorazky
- Division of Neurology, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, 555 University Avenue, Toronto, ON M5G 1X8, Canada; Program for Genetics and Genome Biology, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Roberto Mendoza-Londono
- Division of Clinical and Metabolic Genetics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Ahmad Hassan
- Department of Paediatrics, University of Toronto, Toronto, Ontario, Canada
| | - Tapas Kulkarni
- Department of Paediatrics, University of Toronto, Toronto, Ontario, Canada
| | - Kimberly Amburgey
- Division of Neurology, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, 555 University Avenue, Toronto, ON M5G 1X8, Canada; Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - James J Dowling
- Division of Neurology, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, 555 University Avenue, Toronto, ON M5G 1X8, Canada; Program for Genetics and Genome Biology, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada; Department of Paediatrics, University of Toronto, Toronto, Ontario, Canada; Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada.
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46
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O'Connell K, Rooney T, Alabaf S, Ramdas S, Beeson D, Palace J. Pregnancy outcomes in patients with congenital myasthenic syndromes. Muscle Nerve 2022; 66:345-348. [PMID: 35661384 DOI: 10.1002/mus.27653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 05/22/2022] [Accepted: 05/28/2022] [Indexed: 11/08/2022]
Abstract
INTRODUCTION/AIMS The congenital myasthenic syndromes (CMS) are a heterogeneous group of inherited disorders that affect neuromuscular junction transmission. Data on pregnancy outcomes in women with CMS are limited due to their infrequency. In this study we explored pregnancy with CMS in a large cohort of women attending a national specialty clinic in England. METHODS All women with CMS who had a documented pregnancy were invited to complete a questionnaire assessing clinical status during pregnancy and postpartum, pregnancy outcomes, fetal outcomes, and medication use during pregnancy. RESULTS Among 16 women with CMS (acetylcholine receptor deficiency [CHRNE], slow channel syndrome [CHRNA1], DOK7, RAPSYN and glycosylation [DPAGT1 and GFPT1]), 27 pregnancies were recorded: 26 single pregnancies and 1 twin pregnancy. Symptom worsening was reported in 63% of pregnancies, but recovery to baseline function was seen in all but one patient. Miscarriage and cesarean section occurred in 31% and 33% of the women, respectively. Over half of the patients continued taking their medication during pregnancy, which included pyridostigmine (n = 10), 3,4-diaminopyridine (n = 9), ephedrine (n = 3), salbutamol (n = 3), and quinidine (n = 1). No fetal malformations were recorded. DISCUSSION Our results show that clinical worsening during pregnancy was common but rarely persistent. The majority of women with CMS can safely plan pregnancy, but close follow-up is required from their neurology and obstetric teams. Although we identified no safety concerns, continued medication use should be reviewed on a case-by-case basis.
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Affiliation(s)
- Karen O'Connell
- Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford, UK
| | - Tatiana Rooney
- Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford, UK
| | - Setareh Alabaf
- Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford, UK
| | - Sithara Ramdas
- Department of Paediatric Neurology, John Radcliffe Hospital, Oxford, UK
| | - David Beeson
- Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford, UK
- Neurosciences Group, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Jacqueline Palace
- Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford, UK
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Zhang P, Lao D, Chen H, Zhao B, Du Q, Zhai Q, Ye X, Yu B. Neuromuscular junction dysfunctions due to immune checkpoint inhibitors therapy: An analysis of FAERS data in the past 15 years. Front Immunol 2022; 13:778635. [PMID: 36081514 PMCID: PMC9446345 DOI: 10.3389/fimmu.2022.778635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 07/28/2022] [Indexed: 11/13/2022] Open
Abstract
IntroductionThe adverse effects of neuromuscular junction dysfunctions caused by immune checkpoint inhibitor (ICI) drugs have not been thoroughly assessed in the clinics.ObjectiveTo assess the neuromuscular junction dysfunctions in cancer patients with adverse events caused by ICI therapy by searching the Food and Drug Administration Adverse Event Reporting System (FAERS) database.MethodsThe FAERS data from January 2004 to December 2020 were collected to analyze the association between neuromuscular connection dysfunction and ICI use. Disproportionate analysis and Bayesian analysis were used to quantify the association between the neuromuscular junction dysfunctions and ICIs. The onset time and outcome of neuromuscular junction dysfunctions in different ICI regimens were also compared.ResultsOut of 88,617 adverse event reports, 557 neuromuscular junction dysfunction reports (0.63%) were analyzed. Marketed ICI drugs, including ipilimumab, nivolumab, pembrolizumab, atezolizumab, durvalumab, cemiplimab, avelumab, as well as their combinations, showed positive associations with four detection methods. Most of the adverse event reports were associated with the use of nivolumab (53.32%) and pembrolizumab (31.96%). However, nivolumab-related neuromuscular junction dysfunctions were similar with pembrolizumab (33.33% vs 33.14%, p > 0.05). The onset time of neuromuscular junction dysfunctions showed no significant difference among different ICIs (p > 0.05).ConclusionsAnalysis of FAERS data identified that over 30% (32.85%) of reports of neuromuscular junction dysfunctions resulted in death. Ongoing monitoring, risk evaluations, and further comparative studies of ICIs should be considered.
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Affiliation(s)
- Ping Zhang
- Department of Pharmacy, Tongren Hospital, Shanghai Jiao Tong University, School of Medicine, Shanghai, China
| | - Donghui Lao
- Department of Pharmacy, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Haoyan Chen
- Department of Pharmacy, Tongren Hospital, Shanghai Jiao Tong University, School of Medicine, Shanghai, China
| | - Bin Zhao
- Department of Pharmacy Pharmacology, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
| | - Qiong Du
- School of Medicine, Fudan University, Shanghai, China
- Department of Pharmacy, Fudan University Shanghai Cancer Center, Shanghai, China
| | - Qing Zhai
- School of Medicine, Fudan University, Shanghai, China
- Department of Pharmacy, Fudan University Shanghai Cancer Center, Shanghai, China
| | - Xuan Ye
- School of Medicine, Fudan University, Shanghai, China
- Department of Pharmacy, Fudan University Shanghai Cancer Center, Shanghai, China
- *Correspondence: Bo Yu, ; Xuan Ye,
| | - Bo Yu
- Department of Pharmacy, Tongren Hospital, Shanghai Jiao Tong University, School of Medicine, Shanghai, China
- *Correspondence: Bo Yu, ; Xuan Ye,
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48
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Al-Lahham T, Lacomis D. What is in the Neuromuscular Junction Literature? J Clin Neuromuscul Dis 2022; 23:189-200. [PMID: 35608642 DOI: 10.1097/cnd.0000000000000403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
ABSTRACT This update covers a number of treatment topics starting with Fc receptor inhibitors and the Federal Drug Administration approval of efgartigimod. Some uncertainties regarding the use of corticosteroids are addressed, namely the risk of exacerbation with initiation of treatment and how to taper. The presence and potential importance of antibody overshoot following plasmapheresis is noted and the evolving increase in usefulness of acetylcholine receptor antibodies in diagnosing ocular myasthenia. Several recent series and case reports regarding coronavirus 2019 and myasthenia gravis are reviewed. The topics of myasthenia gravis and pregnancy, and another look at thymectomy in MG are provided. Finally, a couple of case reports on Lambert-Eaton myasthenic syndrome concentrate on the ice pack test and an autoantibody association with paraneoplastic cerebellar degeneration and Lambert-Eaton myasthenic syndrome in the same patient.
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Affiliation(s)
| | - David Lacomis
- Departments of Neurology and
- Pathology (Neuropathology), University of Pittsburgh School of Medicine, Pittsburgh, PA
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Abstract
BACKGROUND Myasthenia gravis is largely a treatable disease, but it can result in significant morbidity and even mortality, which can usually be avoided, or at least mitigated, with timely diagnosis and appropriate treatment of the disease. Objective: this review aims to summarize the main practical aspects of the diagnostic approach, treatment and care of myasthenic patients. METHODS The authors performed a non-systematic critical review summarizing the main practical aspects of myasthenia gravis. RESULTS Most patients with myasthenia have autoantibodies targeted at acetylcholine receptors or, less commonly, muscle-specific kinase - MuSK. Electrophysiology plays an important role in the diagnosis of neuromuscular junction dysfunction. The central clinical manifestation of myasthenia gravis is fatigable muscle weakness, which can affect eye, bulbar, respiratory, and limb muscles. With rare exceptions, patients have a good response to symptomatic treatment, but corticosteroids and/or immunosuppressants are usually also necessary to obtain good control of the manifestations of the disease. CONCLUSION Knowledge of the peculiar aspects of their clinical and electrophysiological presentations is important for the diagnosis. Likewise, specific treatment and response time to each drug are crucial for proper care.
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Affiliation(s)
- Eduardo de Paula Estephan
- Universidade de São Paulo, Faculdade de Medicina, Departamento de Neurologia, São Paulo SP, Brazil
- Fundação Faculdade Regional de Medicina de São José do Rio Preto, Hospital de Base, Departamento de Neurologia, São José do Rio Preto SP, Brazil
- Faculdade de Medicina Santa Marcelina, São Paulo SP, Brazil
| | - José Pedro Soares Baima
- Universidade de São Paulo, Faculdade de Medicina, Departamento de Neurologia, São Paulo SP, Brazil
| | - Antonio Alberto Zambon
- Universidade de São Paulo, Faculdade de Medicina, Departamento de Neurologia, São Paulo SP, Brazil
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50
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Liberman M, Chavez M, Nash TR, Vila OF, Vunjak-Novakovic G. Engineering and Characterization of an Optogenetic Model of the Human Neuromuscular Junction. J Vis Exp 2022. [PMID: 35499350 PMCID: PMC10061228 DOI: 10.3791/63759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Many neuromuscular diseases, such as myasthenia gravis (MG), are associated with dysfunction of the neuromuscular junction (NMJ), which is difficult to characterize in animal models due to physiological differences between animals and humans. Tissue engineering offers opportunities to provide in vitro models of functional human NMJs that can be used to diagnose and investigate NMJ pathologies and test potential therapeutics. By incorporating optogenetic proteins into induced pluripotent stem cells (iPSCs), we generated neurons that can be stimulated with specific wavelengths of light. If the NMJ is healthy and functional, a neurochemical signal from the motoneuron results in muscle contraction. Through the integration of optogenetics and microfabrication with tissue engineering, we established an unbiased and automated methodology for characterizing NMJ function using video analysis. A standardized protocol was developed for NMJ formation, optical stimulation with simultaneous video recording, and video analysis of tissue contractility. Stimulation of optogenetic motoneurons by light to induce skeletal muscle contractions recapitulates human NMJ physiology and allows for repeated functional measurements of NMJ over time and in response to various inputs. We demonstrate this platform's ability to show functional improvements in neuromuscular connectivity over time and characterize the damaging effects of patient MG antibodies or neurotoxins on NMJ function.
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Affiliation(s)
| | - Miguel Chavez
- Department of Biomedical Engineering, Columbia University
| | - Trevor R Nash
- Department of Biomedical Engineering, Columbia University; Department of Medicine, Columbia University
| | - Olaia F Vila
- Department of Biomedical Engineering, Columbia University; Gladstone Institutes;
| | - Gordana Vunjak-Novakovic
- Department of Biomedical Engineering, Columbia University; Department of Medicine, Columbia University; College of Dental Medicine, Columbia University;
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