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Zhao M, Dai B, Li X, Zhang Y, Qiao C, Qin Y, Li Z, Li Q, Wang S, Yang Y, Chen Y. RAPSYN-mediated neddylation of BCR-ABL alternatively determines the fate of Philadelphia chromosome-positive leukemia. eLife 2024; 12:RP88375. [PMID: 38865175 PMCID: PMC11168747 DOI: 10.7554/elife.88375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2024] Open
Abstract
Philadelphia chromosome-positive (Ph+) leukemia is a fatal hematological malignancy. Although standard treatments with tyrosine kinase inhibitors (TKIs) have achieved remarkable success in prolonging patient survival, intolerance, relapse, and TKI resistance remain serious issues for patients with Ph+ leukemia. Here, we report a new leukemogenic process in which RAPSYN and BCR-ABL co-occur in Ph+ leukemia, and RAPSYN mediates the neddylation of BCR-ABL. Consequently, neddylated BCR-ABL enhances the stability by competing its c-CBL-mediated degradation. Furthermore, SRC phosphorylates RAPSYN to activate its NEDD8 E3 ligase activity, promoting BCR-ABL stabilization and disease progression. Moreover, in contrast to in vivo ineffectiveness of PROTAC-based degraders, depletion of RAPSYN expression, or its ligase activity decreased BCR-ABL stability and, in turn, inhibited tumor formation and growth. Collectively, these findings represent an alternative to tyrosine kinase activity for the oncoprotein and leukemogenic cells and generate a rationale of targeting RAPSYN-mediated BCR-ABL neddylation for the treatment of Ph+ leukemia.
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MESH Headings
- Fusion Proteins, bcr-abl/metabolism
- Fusion Proteins, bcr-abl/genetics
- Humans
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/genetics
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/metabolism
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/drug therapy
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/pathology
- Animals
- Mice
- NEDD8 Protein/metabolism
- NEDD8 Protein/genetics
- Cell Line, Tumor
- Ubiquitin-Protein Ligases/metabolism
- Ubiquitin-Protein Ligases/genetics
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Affiliation(s)
- Mengya Zhao
- Laboratory of Chemical Biology, School of Life Science and Technology, China Pharmaceutical UniversityNanjingChina
| | - Beiying Dai
- State Key Laboratory of Natural Medicines, China Pharmaceutical UniversityNanjingChina
| | - Xiaodong Li
- Laboratory of Chemical Biology, School of Life Science and Technology, China Pharmaceutical UniversityNanjingChina
| | - Yixin Zhang
- State Key Laboratory of Natural Medicines, China Pharmaceutical UniversityNanjingChina
| | - Chun Qiao
- State Key Laboratory of Natural Medicines, China Pharmaceutical UniversityNanjingChina
- Department of Hematology, The First Affiliated Hospital of Nanjing Medical University, Jiangsu Province HospitalNanjingChina
| | - Yaru Qin
- State Key Laboratory of Natural Medicines, China Pharmaceutical UniversityNanjingChina
| | - Zhao Li
- Laboratory of Chemical Biology, School of Life Science and Technology, China Pharmaceutical UniversityNanjingChina
| | - Qingmei Li
- Laboratory of Chemical Biology, School of Life Science and Technology, China Pharmaceutical UniversityNanjingChina
| | - Shuzhen Wang
- Laboratory of Chemical Biology, School of Life Science and Technology, China Pharmaceutical UniversityNanjingChina
| | - Yong Yang
- State Key Laboratory of Natural Medicines, China Pharmaceutical UniversityNanjingChina
| | - Yijun Chen
- Laboratory of Chemical Biology, School of Life Science and Technology, China Pharmaceutical UniversityNanjingChina
- State Key Laboratory of Natural Medicines, China Pharmaceutical UniversityNanjingChina
- Chongqing Innovation Institute of China Pharmaceutical UniversityChongqingChina
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2
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De Cicco T, Pęziński M, Wójcicka O, Pradhan BS, Jabłońska M, Rottner K, Prószyński TJ. Cortactin interacts with αDystrobrevin-1 and regulates murine neuromuscular junction morphology. Eur J Cell Biol 2024; 103:151409. [PMID: 38579603 DOI: 10.1016/j.ejcb.2024.151409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2023] [Revised: 03/24/2024] [Accepted: 03/29/2024] [Indexed: 04/07/2024] Open
Abstract
Neuromuscular junctions transmit signals from the nervous system to skeletal muscles, triggering their contraction, and their proper organization is essential for breathing and voluntary movements. αDystrobrevin-1 is a cytoplasmic component of the dystrophin-glycoprotein complex and has pivotal functions in regulating the integrity of muscle fibers and neuromuscular junctions. Previous studies identified that αDystrobrevin-1 functions in the organization of the neuromuscular junction and that its phosphorylation in the C-terminus is required in this process. Our proteomic screen identified several putative αDystrobrevin-1 interactors recruited to the Y730 site in phosphorylated and unphosphorylated states. Amongst various actin-modulating proteins, we identified the Arp2/3 complex regulator cortactin. We showed that similarly to αDystrobrevin-1, cortactin is strongly enriched at the neuromuscular postsynaptic machinery and obtained results suggesting that these two proteins interact in cell homogenates and at the neuromuscular junctions. Analysis of synaptic morphology in cortactin knockout mice showed abnormalities in the slow-twitching soleus muscle and not in the fast-twitching tibialis anterior. However, muscle strength examination did not reveal apparent deficits in knockout animals.
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Affiliation(s)
- Teresa De Cicco
- Łukasiewicz Research Network - PORT Polish Center for Technology Development, Stabłowicka 147, Wrocław 54-066, Poland; Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, Warsaw 02-093, Poland
| | - Marcin Pęziński
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, Warsaw 02-093, Poland
| | - Olga Wójcicka
- Łukasiewicz Research Network - PORT Polish Center for Technology Development, Stabłowicka 147, Wrocław 54-066, Poland
| | - Bhola Shankar Pradhan
- Łukasiewicz Research Network - PORT Polish Center for Technology Development, Stabłowicka 147, Wrocław 54-066, Poland
| | - Margareta Jabłońska
- Łukasiewicz Research Network - PORT Polish Center for Technology Development, Stabłowicka 147, Wrocław 54-066, Poland
| | - Klemens Rottner
- Division of Molecular Cell Biology, Zoological Institute, Technische Universität Braunschweig, Germany; Department of Cell Biology, Helmholtz Centre for Infection Research, Inhoffenstraße 7, Braunschweig 38124, Germany
| | - Tomasz J Prószyński
- Łukasiewicz Research Network - PORT Polish Center for Technology Development, Stabłowicka 147, Wrocław 54-066, Poland; Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, Warsaw 02-093, Poland.
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3
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Chen BH, Lin ZY, Zeng XX, Jiang YH, Geng F. LRP4-related signalling pathways and their regulatory role in neurological diseases. Brain Res 2024; 1825:148705. [PMID: 38065285 DOI: 10.1016/j.brainres.2023.148705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 11/17/2023] [Accepted: 12/03/2023] [Indexed: 01/28/2024]
Abstract
The mechanism of action of low-density lipoprotein receptor related protein 4 (LRP4) is mediated largely via the Agrin-LRP4-MuSK signalling pathway in the nervous system. LRP4 contributes to the development of synapses in the peripheral nervous system (PNS). It interacts with signalling molecules such as the amyloid beta-protein precursor (APP) and the wingless type protein (Wnt). Its mechanisms of action are complex and mediated via interaction between the pre-synaptic motor neuron and post-synaptic muscle cell in the PNS, which enhances the development of the neuromuscular junction (NMJ). LRP4 may function differently in the central nervous system (CNS) than in the PNS, where it regulates ATP and glutamate release via astrocytes. It mayaffect the growth and development of the CNS by controlling the energy metabolism. LRP4 interacts with Agrin to maintain dendrite growth and density in the CNS. The goal of this article is to review the current studies involving relevant LRP4 signaling pathways in the nervous system. The review also discusses the clinical and etiological roles of LRP4 in neurological illnesses, such as myasthenia gravis, Alzheimer's disease and epilepsy. In this review, we provide a theoretical foundation for the pathogenesis and therapeutic application of LRP4 in neurologic diseases.
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Affiliation(s)
- Bai-Hui Chen
- Department of Physiology, Shantou University Medical College, Shantou 515041, China
| | - Ze-Yu Lin
- Department of Physiology, Shantou University Medical College, Shantou 515041, China
| | - Xiao-Xue Zeng
- Department of Physiology, Shantou University Medical College, Shantou 515041, China
| | - Yi-Han Jiang
- Department of Physiology, Shantou University Medical College, Shantou 515041, China
| | - Fei Geng
- Department of Physiology, Shantou University Medical College, Shantou 515041, China; Guangdong Provincial Key Laboratory of Infectious Diseases and Molecular Immunopathology, Shantou University Medical College, Shantou 515041, China.
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4
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Chen X, Qiu J, Gao Z, Liu B, Zhang C, Yu W, Yang J, Shen Y, Qi L, Yao X, Sun H, Yang X. Myasthenia gravis: Molecular mechanisms and promising therapeutic strategies. Biochem Pharmacol 2023; 218:115872. [PMID: 37865142 DOI: 10.1016/j.bcp.2023.115872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Revised: 10/16/2023] [Accepted: 10/18/2023] [Indexed: 10/23/2023]
Abstract
Myasthenia gravis (MG) is a type of autoimmune disease caused by the blockage of neuromuscular junction transmission owing to the attack of autoantibodies on transmission-related proteins. Related antibodies, such as anti-AChR, anti-MuSK and anti-LRP4 antibodies, can be detected in most patients with MG. Although traditional therapies can control most symptoms, several challenges remain to be addressed, necessitating the development of more effective and safe treatment strategies for MG. With the in-depth exploration on the mechanism and immune targets of MG, effective therapies, especially therapies using biologicals, have been reported recently. Given the important roles of immune cells, cytokines and intercellular interactions in the pathological process of MG, B-cell targeted therapy, T-cell targeted therapy, proteasome inhibitors targeting plasma cell, complement inhibitors, FcRn inhibitors have been developed for the treatment of MG. Although these novel therapies exert good therapeutic effects, they may weaken the immunity and increase the risk of infection in MG patients. This review elaborates on the pathogenesis of MG and discusses the advantages and disadvantages of the strategies of traditional treatment and biologicals. In addition, this review emphasises that combined therapy may have better therapeutic effects and reducing the risk of side effects of treatments, which has great prospects for the treatment of MG. With the deepening of research on immunotherapy targets in MG, novel opportunities and challenges in the treatment of MG will be introduced.
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Affiliation(s)
- Xin Chen
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, Department of Neurology, Affiliated Hospital of Nantong University, Nantong University, Nantong, Jiangsu Province 226001, PR China
| | - Jiayi Qiu
- Department of Clinical Medicine, Medical College, Nantong University, Nantong, Jiangsu Province 226001, PR China
| | - Zihui Gao
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, Department of Neurology, Affiliated Hospital of Nantong University, Nantong University, Nantong, Jiangsu Province 226001, PR China
| | - Boya Liu
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, Department of Neurology, Affiliated Hospital of Nantong University, Nantong University, Nantong, Jiangsu Province 226001, PR China
| | - Chen Zhang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, Department of Neurology, Affiliated Hospital of Nantong University, Nantong University, Nantong, Jiangsu Province 226001, PR China
| | - Weiran Yu
- Department of Clinical Medicine, Medical College, Nantong University, Nantong, Jiangsu Province 226001, PR China
| | - Jiawen Yang
- Department of Clinical Medicine, Medical College, Nantong University, Nantong, Jiangsu Province 226001, PR China
| | - Yuntian Shen
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, Department of Neurology, Affiliated Hospital of Nantong University, Nantong University, Nantong, Jiangsu Province 226001, PR China
| | - Lei Qi
- Department of Emergency Medicine, Affiliated Hospital of Nantong University, Nantong, Jiangsu Province 226001, PR China
| | - Xinlei Yao
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, Department of Neurology, Affiliated Hospital of Nantong University, Nantong University, Nantong, Jiangsu Province 226001, PR China.
| | - Hualin Sun
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, Department of Neurology, Affiliated Hospital of Nantong University, Nantong University, Nantong, Jiangsu Province 226001, PR China.
| | - Xiaoming Yang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, Department of Neurology, Affiliated Hospital of Nantong University, Nantong University, Nantong, Jiangsu Province 226001, PR China.
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5
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Chrestia JF, Turani O, Araujo NR, Hernando G, Esandi MDC, Bouzat C. Regulation of nicotinic acetylcholine receptors by post-translational modifications. Pharmacol Res 2023; 190:106712. [PMID: 36863428 DOI: 10.1016/j.phrs.2023.106712] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 02/21/2023] [Accepted: 02/24/2023] [Indexed: 03/04/2023]
Abstract
Nicotinic acetylcholine receptors (nAChRs) comprise a family of pentameric ligand-gated ion channels widely distributed in the central and peripheric nervous system and in non-neuronal cells. nAChRs are involved in chemical synapses and are key actors in vital physiological processes throughout the animal kingdom. They mediate skeletal muscle contraction, autonomic responses, contribute to cognitive processes, and regulate behaviors. Dysregulation of nAChRs is associated with neurological, neurodegenerative, inflammatory and motor disorders. In spite of the great advances in the elucidation of nAChR structure and function, our knowledge about the impact of post-translational modifications (PTMs) on nAChR functional activity and cholinergic signaling has lagged behind. PTMs occur at different steps of protein life cycle, modulating in time and space protein folding, localization, function, and protein-protein interactions, and allow fine-tuned responses to changes in the environment. A large body of evidence demonstrates that PTMs regulate all levels of nAChR life cycle, with key roles in receptor expression, membrane stability and function. However, our knowledge is still limited, restricted to a few PTMs, and many important aspects remain largely unknown. There is thus a long way to go to decipher the association of aberrant PTMs with disorders of cholinergic signaling and to target PTM regulation for novel therapeutic interventions. In this review we provide a comprehensive overview of what is known about how different PTMs regulate nAChR.
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Affiliation(s)
- Juan Facundo Chrestia
- Instituto de Investigaciones Bioquímicas de Bahía Blanca, Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca 8000, Argentina
| | - Ornella Turani
- Instituto de Investigaciones Bioquímicas de Bahía Blanca, Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca 8000, Argentina
| | - Noelia Rodriguez Araujo
- Instituto de Investigaciones Bioquímicas de Bahía Blanca, Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca 8000, Argentina
| | - Guillermina Hernando
- Instituto de Investigaciones Bioquímicas de Bahía Blanca, Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca 8000, Argentina
| | - María Del Carmen Esandi
- Instituto de Investigaciones Bioquímicas de Bahía Blanca, Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca 8000, Argentina
| | - Cecilia Bouzat
- Instituto de Investigaciones Bioquímicas de Bahía Blanca, Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca 8000, Argentina.
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6
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Kramer JJ, Boon HTM, Leijten QH, Ter Laak H, Eshuis L, Kusters B, van Doorn JLM, Kamsteeg EJ, Eymard B, Doorduin J, Voermans NC. Dystrophic Myopathy of the Diaphragm with Recurrent Severe Respiratory Failure is Congenital Myasthenic Syndrome 11. J Neuromuscul Dis 2023; 10:271-277. [PMID: 36591657 PMCID: PMC10041432 DOI: 10.3233/jnd-221542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
We here present the case of a patient with a congenital myasthenic syndrome (CMS) due to pathogenic variants in the RAPSN gene. During childhood he experienced recurrent episodes of respiratory failure during respiratory infections. This and other cases were reported as isolated dystrophy of the diaphragmatic musculature. In adulthood, whole exome sequencing revealed two heterozygous pathogenic variants in the RAPSN gene. This led to the revision of the diagnosis to rapsyn CMS11 (OMIM:616326, MONDO:0014588). EMG, muscle ultrasound and the revision of muscle biopsies taken in childhood support this diagnosis. After the revision of the diagnosis, treatment with pyridostigmine was started. This resulted in a reduction of fatigability and an improvement in functional abilities and quality of life.
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Affiliation(s)
- J J Kramer
- Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - H T M Boon
- Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, The Netherlands
| | | | - Henk Ter Laak
- Department of Pathology, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - L Eshuis
- Department of Genetics, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - B Kusters
- Department of Pathology, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - J L M van Doorn
- Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - E J Kamsteeg
- Department of Genetics, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - B Eymard
- Institute de Myologie, Paris, France
| | - J Doorduin
- Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - N C Voermans
- Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, The Netherlands
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7
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Alignment of Skeletal Muscle Cells Facilitates Acetylcholine Receptor Clustering and Neuromuscular Junction Formation with Co-Cultured Human iPSC-Derived Motor Neurons. Cells 2022; 11:cells11233760. [PMID: 36497020 PMCID: PMC9738074 DOI: 10.3390/cells11233760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 11/04/2022] [Accepted: 11/20/2022] [Indexed: 11/27/2022] Open
Abstract
In vitro neuromuscular junction (NMJ) models are powerful tools for studying neuromuscular disorders. Although linearly patterned culture surfaces have been reported to be useful for the formation of in vitro NMJ models using mouse motor neuron (MNs) and skeletal muscle (SkM) myotubes, it is unclear how the linearly patterned culture surface increases acetylcholine receptor (AChR) clustering, one of the steps in the process of NMJ formation, and whether this increases the in vitro NMJ formation efficiency of co-cultured human MNs and SkM myotubes. In this study, we investigated the effects of a linearly patterned culture surface on AChR clustering in myotubes and examined the possible mechanism of the increase in AChR clustering using gene expression analysis, as well as the effects of the patterned surface on the efficiency of NMJ formation between co-cultured human SkM myotubes and human iPSC-derived MNs. Our results suggest that better differentiation of myotubes on the patterned surface, compared to the flat surface, induced gene expression of integrin α7 and AChR ε-subunit, thereby increasing AChR clustering. Furthermore, we found that the number of NMJs between human SkM cells and MNs increased upon co-culture on the linearly patterned surface, suggesting the usefulness of the patterned surface for creating in vitro human NMJ models.
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8
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Hörner SJ, Couturier N, Bruch R, Koch P, Hafner M, Rudolf R. hiPSC-Derived Schwann Cells Influence Myogenic Differentiation in Neuromuscular Cocultures. Cells 2021; 10:cells10123292. [PMID: 34943800 PMCID: PMC8699767 DOI: 10.3390/cells10123292] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 11/20/2021] [Accepted: 11/21/2021] [Indexed: 12/13/2022] Open
Abstract
Motoneurons, skeletal muscle fibers, and Schwann cells form synapses, termed neuromuscular junctions (NMJs). These control voluntary body movement and are affected in numerous neuromuscular diseases. Therefore, a variety of NMJ in vitro models have been explored to enable mechanistic and pharmacological studies. So far, selective integration of Schwann cells in these models has been hampered, due to technical limitations. Here we present robust protocols for derivation of Schwann cells from human induced pluripotent stem cells (hiPSC) and their coculture with hiPSC-derived motoneurons and C2C12 muscle cells. Upon differentiation with tuned BMP signaling, Schwann cells expressed marker proteins, S100b, Gap43, vimentin, and myelin protein zero. Furthermore, they displayed typical spindle-shaped morphologies with long processes, which often aligned with motoneuron axons. Inclusion of Schwann cells in coculture experiments with hiPSC-derived motoneurons and C2C12 myoblasts enhanced myotube growth and affected size and number of acetylcholine receptor plaques on myotubes. Altogether, these data argue for the availability of a consistent differentiation protocol for Schwann cells and their amenability for functional integration into neuromuscular in vitro models, fostering future studies of neuromuscular mechanisms and disease.
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Affiliation(s)
- Sarah Janice Hörner
- Institute of Molecular and Cell Biology, Mannheim University of Applied Sciences, 68163 Mannheim, Germany; (S.J.H.); (N.C.); (R.B.); (M.H.)
- Interdisciplinary Center for Neurosciences, Heidelberg University, 69120 Heidelberg, Germany
| | - Nathalie Couturier
- Institute of Molecular and Cell Biology, Mannheim University of Applied Sciences, 68163 Mannheim, Germany; (S.J.H.); (N.C.); (R.B.); (M.H.)
| | - Roman Bruch
- Institute of Molecular and Cell Biology, Mannheim University of Applied Sciences, 68163 Mannheim, Germany; (S.J.H.); (N.C.); (R.B.); (M.H.)
| | - Philipp Koch
- Central Institute of Mental Health, Medical Faculty Mannheim of Heidelberg University, 68159 Mannheim, Germany;
- Hector Institute for Translational Brain Research (HITBR gGmbH), 68159 Mannheim, Germany
- German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Mathias Hafner
- Institute of Molecular and Cell Biology, Mannheim University of Applied Sciences, 68163 Mannheim, Germany; (S.J.H.); (N.C.); (R.B.); (M.H.)
- Institute of Medical Technology, Mannheim University of Applied Sciences and Heidelberg University, 68163 Mannheim, Germany
| | - Rüdiger Rudolf
- Institute of Molecular and Cell Biology, Mannheim University of Applied Sciences, 68163 Mannheim, Germany; (S.J.H.); (N.C.); (R.B.); (M.H.)
- Interdisciplinary Center for Neurosciences, Heidelberg University, 69120 Heidelberg, Germany
- Institute of Medical Technology, Mannheim University of Applied Sciences and Heidelberg University, 68163 Mannheim, Germany
- Correspondence:
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9
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Alvarez-Suarez P, Nowak N, Protasiuk-Filipunas A, Yamazaki H, Prószyński TJ, Gawor M. Drebrin Regulates Acetylcholine Receptor Clustering and Organization of Microtubules at the Postsynaptic Machinery. Int J Mol Sci 2021; 22:9387. [PMID: 34502296 PMCID: PMC8430516 DOI: 10.3390/ijms22179387] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 08/20/2021] [Accepted: 08/24/2021] [Indexed: 01/07/2023] Open
Abstract
Proper muscle function depends on the neuromuscular junctions (NMJs), which mature postnatally to complex "pretzel-like" structures, allowing for effective synaptic transmission. Postsynaptic acetylcholine receptors (AChRs) at NMJs are anchored in the actin cytoskeleton and clustered by the scaffold protein rapsyn, recruiting various actin-organizing proteins. Mechanisms driving the maturation of the postsynaptic machinery and regulating rapsyn interactions with the cytoskeleton are still poorly understood. Drebrin is an actin and microtubule cross-linker essential for the functioning of the synapses in the brain, but its role at NMJs remains elusive. We used immunohistochemistry, RNA interference, drebrin inhibitor 3,5-bis-trifluoromethyl pyrazole (BTP2) and co-immunopreciptation to explore the role of this protein at the postsynaptic machinery. We identify drebrin as a postsynaptic protein colocalizing with the AChRs both in vitro and in vivo. We also show that drebrin is enriched at synaptic podosomes. Downregulation of drebrin or blocking its interaction with actin in cultured myotubes impairs the organization of AChR clusters and the cluster-associated microtubule network. Finally, we demonstrate that drebrin interacts with rapsyn and a drebrin interactor, plus-end-tracking protein EB3. Our results reveal an interplay between drebrin and cluster-stabilizing machinery involving rapsyn, actin cytoskeleton, and microtubules.
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Affiliation(s)
- Paloma Alvarez-Suarez
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland; (P.A.-S.); (N.N.); (A.P.-F.); (T.J.P.)
| | - Natalia Nowak
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland; (P.A.-S.); (N.N.); (A.P.-F.); (T.J.P.)
| | - Anna Protasiuk-Filipunas
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland; (P.A.-S.); (N.N.); (A.P.-F.); (T.J.P.)
| | - Hiroyuki Yamazaki
- Gunma University Graduate School of Medicine, Maebashi, Gunma 371-8511, Japan;
| | - Tomasz J. Prószyński
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland; (P.A.-S.); (N.N.); (A.P.-F.); (T.J.P.)
| | - Marta Gawor
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland; (P.A.-S.); (N.N.); (A.P.-F.); (T.J.P.)
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10
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Medina-Moreno A, Henríquez JP. Maturation of a postsynaptic domain: Role of small Rho GTPases in organising nicotinic acetylcholine receptor aggregates at the vertebrate neuromuscular junction. J Anat 2021; 241:1148-1156. [PMID: 34342888 DOI: 10.1111/joa.13526] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 07/15/2021] [Accepted: 07/20/2021] [Indexed: 12/13/2022] Open
Abstract
The neuromuscular junction (NMJ) is the peripheral synapse formed between a motor axon and a skeletal muscle fibre that allows muscle contraction and the coordinated movement in many species. A main hallmark of the mature NMJ is the assembly of nicotinic acetylcholine receptor (nAChR) aggregates in the muscle postsynaptic domain, that distributes in perfect apposition to presynaptic motor terminals. To assemble its unique functional architecture, initial embryonic NMJs undergo an early postnatal maturation process characterised by the transformation of homogenous nAChR-containing plaques to elaborate and branched pretzel-like structures. In spite of a detailed morphological characterisation, the molecular mechanisms controlling the intracellular scaffolding that organises a postsynaptic domain at the mature NMJ have not been fully elucidated. In this review, we integrate evidence of key processes and molecules that have shed light on our current understanding of the NMJ maturation process. On the one hand, we consider in vitro studies revealing the potential role of podosome-like structures to define discrete low nAChR-containing regions to consolidate a plaque-to-pretzel transition at the NMJ. On the other hand, we focus on in vitro and in vivo evidence demonstrating that members of the Ras homologous (Rho) protein family of small GTPases (small Rho GTPases) play indispensable roles on NMJ maturation by regulating the stability of nAChR aggregates. We combine this evidence to propose that small Rho GTPases are key players in the assembly of podosome-like structures that drive the postsynaptic maturation of vertebrate NMJs.
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Affiliation(s)
- Angelymar Medina-Moreno
- Laboratory of Neuromuscular Studies (NeSt Lab), Department of Cell Biology, Faculty of Biological Sciences, Center for Advanced Microscopy (CMA BioBio), Universidad de Concepción, Concepción, Chile
| | - Juan Pablo Henríquez
- Laboratory of Neuromuscular Studies (NeSt Lab), Department of Cell Biology, Faculty of Biological Sciences, Center for Advanced Microscopy (CMA BioBio), Universidad de Concepción, Concepción, Chile
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Xing G, Jing H, Yu Z, Chen P, Wang H, Xiong WC, Mei L. Membraneless condensates by Rapsn phase separation as a platform for neuromuscular junction formation. Neuron 2021; 109:1963-1978.e5. [PMID: 34033754 DOI: 10.1016/j.neuron.2021.04.021] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 03/27/2021] [Accepted: 04/22/2021] [Indexed: 12/29/2022]
Abstract
Our daily life depends on muscle contraction, a process that is controlled by the neuromuscular junction (NMJ). However, the mechanisms of NMJ assembly remain unclear. Here we show that Rapsn, a protein critical for NMJ formation, undergoes liquid-liquid phase separation (LLPS) and condensates into liquid-like assemblies. Such assemblies can recruit acetylcholine receptors (AChRs), cytoskeletal proteins, and signaling proteins for postsynaptic differentiation. Rapsn LLPS requires multivalent binding of tetratricopeptide repeats (TPRs) and is increased by Musk signaling. The capacity of Rapsn to condensate and co-condensate with interaction proteins is compromised by mutations of congenital myasthenic syndromes (CMSs). NMJ formation is impaired in mutant mice carrying a CMS-associated, LLPS-deficient mutation. These results reveal a critical role of Rapsn LLPS in forming a synaptic semi-membraneless compartment for NMJ formation.
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Affiliation(s)
- Guanglin Xing
- Department of Neurosciences, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - Hongyang Jing
- Department of Neurosciences, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - Zheng Yu
- Department of Neurosciences, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - Peng Chen
- Department of Neurosciences, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - Hongsheng Wang
- Department of Neurosciences, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - Wen-Cheng Xiong
- Department of Neurosciences, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA; Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH 44106, USA.
| | - Lin Mei
- Department of Neurosciences, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA; Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH 44106, USA.
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An Inside Job: Molecular Determinants for Postsynaptic Localization of Nicotinic Acetylcholine Receptors. Molecules 2021; 26:molecules26113065. [PMID: 34063759 PMCID: PMC8196675 DOI: 10.3390/molecules26113065] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 05/13/2021] [Accepted: 05/15/2021] [Indexed: 11/29/2022] Open
Abstract
Nicotinic acetylcholine receptors (nAChRs) mediate fast synaptic transmission at neuromuscular and autonomic ganglionic synapses in the peripheral nervous system. The postsynaptic localization of muscle ((α1)2β1γδ) and neuronal ((α3β4)2β4) nicotinic receptors at these synapses is mediated by interactions between the nAChR intracellular domains and cytoplasmic scaffolding proteins. Recent high resolution structures and functional studies provide new insights into the molecular determinants that mediate these interactions. Surprisingly, they reveal that the muscle nAChR binds 1–3 rapsyn scaffolding molecules, which dimerize and thereby form an interconnected lattice between receptors. Moreover, rapsyn binds two distinct sites on the nAChR subunit cytoplasmic loops; the MA-helix on one or more subunits and a motif specific to the β subunit. Binding at the latter site is regulated by agrin-induced phosphorylation of βY390, and increases the stoichiometry of rapsyn/AChR complexes. Similarly, the neuronal nAChR may be localized at ganglionic synapses by phosphorylation-dependent interactions with 14-3-3 adaptor proteins which bind specific motifs in each of the α3 subunit cytoplasmic loops. Thus, postsynaptic localization of nAChRs is mediated by regulated interactions with multiple scaffolding molecules, and the stoichiometry of these complexes likely helps regulate the number, density, and stability of receptors at the synapse.
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The association between RAPSN methylation in peripheral blood and breast cancer in the Chinese population. J Hum Genet 2021; 66:1069-1078. [PMID: 33958711 DOI: 10.1038/s10038-021-00933-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 04/15/2021] [Accepted: 04/17/2021] [Indexed: 02/05/2023]
Abstract
DNA methylation in peripheral blood is associated with breast cancer (BC) but has mainly been studied in Caucasian populations. We investigated the association between blood-based methylation of receptor-associated protein of the synapse (RAPSN) and BC in Chinese population. The methylation levels of 12 RAPSN CpG sites were quantitatively evaluated by mass spectrometry in two case-control studies with 283 sporadic BC cases and 331 controls totally. The association was analyzed by logistic regression adjusted for covariants. The RAPSN methylation levels in patients with variant clinical characteristics were investigated by non-parametric tests. We found a significant association between BC and altered RAPSN methylation in blood in women at premenopausal and perimenopausal (age < 50 years old), but not in the elder women. This was approved by two independent case-control studies as well as by combining the subjects of the two studies (taken all subjects together, age < 50 years old, per 5% of methylation, odds ratio (OR) range from 1.17 to 1.30 for two CpG sites; OR = 0.75 for one CpG site; all p values < 0.02). This age-related RAPSN methylation was further modified by human epidermal growth factor receptor 2 (HER2) status (age < 50 years old, HER2 negative, per 5% of methylation, OR range from 1.27 to 1.48 for two CpG sites; OR = 0.76 for one CpG site; all p values < 0.02). We elucidated an association between BC and blood-based RAPSN methylation influenced by age and the status of HER2 in Chinese population.
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Ohkawara B, Ito M, Ohno K. Secreted Signaling Molecules at the Neuromuscular Junction in Physiology and Pathology. Int J Mol Sci 2021; 22:ijms22052455. [PMID: 33671084 PMCID: PMC7957818 DOI: 10.3390/ijms22052455] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 02/22/2021] [Accepted: 02/25/2021] [Indexed: 02/08/2023] Open
Abstract
Signal transduction at the neuromuscular junction (NMJ) is affected in many human diseases, including congenital myasthenic syndromes (CMS), myasthenia gravis, Lambert–Eaton myasthenic syndrome, Isaacs’ syndrome, Schwartz–Jampel syndrome, Fukuyama-type congenital muscular dystrophy, amyotrophic lateral sclerosis, and sarcopenia. The NMJ is a prototypic cholinergic synapse between the motor neuron and the skeletal muscle. Synaptogenesis of the NMJ has been extensively studied, which has also been extrapolated to further understand synapse formation in the central nervous system. Studies of genetically engineered mice have disclosed crucial roles of secreted molecules in the development and maintenance of the NMJ. In this review, we focus on the secreted signaling molecules which regulate the clustering of acetylcholine receptors (AChRs) at the NMJ. We first discuss the signaling pathway comprised of neural agrin and its receptors, low-density lipoprotein receptor-related protein 4 (Lrp4) and muscle-specific receptor tyrosine kinase (MuSK). This pathway drives the clustering of acetylcholine receptors (AChRs) to ensure efficient signal transduction at the NMJ. We also discuss three secreted molecules (Rspo2, Fgf18, and connective tissue growth factor (Ctgf)) that we recently identified in the Wnt/β-catenin and fibroblast growth factors (FGF) signaling pathways. The three secreted molecules facilitate the clustering of AChRs by enhancing the agrin-Lrp4-MuSK signaling pathway.
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Affiliation(s)
- Bisei Ohkawara
- Correspondence: ; Tel.: +81-52-744-2447; Fax: +81-52-744-2449
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Grp94 Regulates the Recruitment of Aneural AChR Clusters for the Assembly of Postsynaptic Specializations by Modulating ADF/Cofilin Activity and Turnover. eNeuro 2020; 7:ENEURO.0025-20.2020. [PMID: 32747457 PMCID: PMC7540925 DOI: 10.1523/eneuro.0025-20.2020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2020] [Revised: 07/27/2020] [Accepted: 07/27/2020] [Indexed: 11/21/2022] Open
Abstract
Temperature is a physiological factor that affects neuronal growth and synaptic homeostasis at the invertebrate neuromuscular junctions (NMJs); however, whether temperature stress could also regulate the structure and function of the vertebrate NMJs remains unclear. In this study, we use Xenopus laevis primary cultures as a vertebrate model system for investigating the involvement of heat shock protein 90 (HSP90) family of stress proteins in NMJ development. First, cold temperature treatment or HSP90 inhibition attenuates the formation of aneural acetylcholine receptor (AChR) clusters, but increases their stability after they are formed, in cultured muscles. HSP90 inhibition specifically affects the stability of aneural AChR clusters and their associated intracellular scaffolding protein rapsyn, instead of causing a global change in cell metabolism and protein expression in Xenopus muscle cultures. Upon synaptogenic stimulation, a specific HSP90 family member, glucose-regulated protein 94 (Grp94), modulates the phosphorylation and dynamic turnover of actin depolymerizing factor (ADF)/cofilin at aneural AChR clusters, leading to the recruitment of AChR molecules from aneural clusters to the assembly of agrin-induced postsynaptic specializations. Finally, postsynaptic Grp94 knock-down significantly inhibits nerve-induced AChR clustering and postsynaptic activity in nerve-muscle co-cultures as demonstrated by live-cell imaging and electrophysiological recording, respectively. Collectively, this study suggests that temperature-dependent alteration in Grp94 expression and activity inhibits the assembly of postsynaptic specializations through modulating ADF/cofilin phosphorylation and activity at aneural AChR clusters, which prevents AChR molecules from being recruited to the postsynaptic sites via actin-dependent vesicular trafficking, at developing vertebrate NMJs.
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Takamori M. Myasthenia Gravis: From the Viewpoint of Pathogenicity Focusing on Acetylcholine Receptor Clustering, Trans-Synaptic Homeostasis and Synaptic Stability. Front Mol Neurosci 2020; 13:86. [PMID: 32547365 PMCID: PMC7272578 DOI: 10.3389/fnmol.2020.00086] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 04/28/2020] [Indexed: 12/18/2022] Open
Abstract
Myasthenia gravis (MG) is a disease of the postsynaptic neuromuscular junction (NMJ) where nicotinic acetylcholine (ACh) receptors (AChRs) are targeted by autoantibodies. Search for other pathogenic antigens has detected the antibodies against muscle-specific tyrosine kinase (MuSK) and low-density lipoprotein-related protein 4 (Lrp4), both causing pre- and post-synaptic impairments. Agrin is also suspected as a fourth pathogen. In a complex NMJ organization centering on MuSK: (1) the Wnt non-canonical pathway through the Wnt-Lrp4-MuSK cysteine-rich domain (CRD)-Dishevelled (Dvl, scaffold protein) signaling acts to form AChR prepatterning with axonal guidance; (2) the neural agrin-Lrp4-MuSK (Ig1/2 domains) signaling acts to form rapsyn-anchored AChR clusters at the innervated stage of muscle; (3) adaptor protein Dok-7 acts on MuSK activation for AChR clustering from “inside” and also on cytoskeleton to stabilize AChR clusters by the downstream effector Sorbs1/2; (4) the trans-synaptic retrograde signaling contributes to the presynaptic organization via: (i) Wnt-MuSK CRD-Dvl-β catenin-Slit 2 pathway; (ii) Lrp4; and (iii) laminins. The presynaptic Ca2+ homeostasis conditioning ACh release is modified by autoreceptors such as M1-type muscarinic AChR and A2A adenosine receptors. The post-synaptic structure is stabilized by: (i) laminin-network including the muscle-derived agrin; (ii) the extracellular matrix proteins (including collagen Q/perlecan and biglycan which link to MuSK Ig1 domain and CRD); and (iii) the dystrophin-associated glycoprotein complex. The study on MuSK ectodomains (Ig1/2 domains and CRD) recognized by antibodies suggested that the MuSK antibodies were pathologically heterogeneous due to their binding to multiple functional domains. Focussing one of the matrix proteins, biglycan which functions in the manner similar to collagen Q, our antibody assay showed the negative result in MG patients. However, the synaptic stability may be impaired by antibodies against MuSK ectodomains because of the linkage of biglycan with MuSK Ig1 domain and CRD. The pathogenic diversity of MG is discussed based on NMJ signaling molecules.
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