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Extracellular matrix and synapse formation. Biosci Rep 2023; 43:232259. [PMID: 36503961 PMCID: PMC9829651 DOI: 10.1042/bsr20212411] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 11/08/2022] [Accepted: 11/24/2022] [Indexed: 12/14/2022] Open
Abstract
The extracellular matrix (ECM) is a complex molecular network distributed throughout the extracellular space of different tissues as well as the neuronal system. Previous studies have identified various ECM components that play important roles in neuronal maturation and signal transduction. ECM components are reported to be involved in neurogenesis, neuronal migration, and axonal growth by interacting or binding to specific receptors. In addition, the ECM is found to regulate synapse formation, the stability of the synaptic structure, and synaptic plasticity. Here, we mainly reviewed the effects of various ECM components on synapse formation and briefly described the related diseases caused by the abnormality of several ECM components.
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2
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Zou S, Pan BX. Post-synaptic specialization of the neuromuscular junction: junctional folds formation, function, and disorders. Cell Biosci 2022; 12:93. [PMID: 35718785 PMCID: PMC9208267 DOI: 10.1186/s13578-022-00829-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 06/05/2022] [Indexed: 11/14/2022] Open
Abstract
Post-synaptic specialization is critical to the neurotransmitter release and action potential conduction. The neuromuscular junctions (NMJs) are the synapses between the motor neurons and muscle cells and have a more specialized post-synaptic membrane than synapses in the central nervous system (CNS). The sarcolemma within NMJ folded to form some invagination portions called junctional folds (JFs), and they have important roles in maintaining the post-synaptic membrane structure. The NMJ formation and the acetylcholine receptor (AChR) clustering signal pathway have been extensively studied and reviewed. Although it has been suggested that JFs are related to maintaining the safety factor of neurotransmitter release, the formation mechanism and function of JFs are still unclear. This review will focus on the JFs about evolution, formation, function, and disorders. Anticipate understanding of where they are coming from and where we will study in the future.
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3
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Ginebaugh SP, Badawi Y, Tarr TB, Meriney SD. Neuromuscular Active Zone Structure and Function in Healthy and Lambert-Eaton Myasthenic Syndrome States. Biomolecules 2022; 12:biom12060740. [PMID: 35740866 PMCID: PMC9221282 DOI: 10.3390/biom12060740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 05/16/2022] [Accepted: 05/18/2022] [Indexed: 12/02/2022] Open
Abstract
The mouse neuromuscular junction (NMJ) has long been used as a model synapse for the study of neurotransmission in both healthy and disease states of the NMJ. Neurotransmission from these neuromuscular nerve terminals occurs at highly organized structures called active zones (AZs). Within AZs, the relationships between the voltage-gated calcium channels and docked synaptic vesicles govern the probability of acetylcholine release during single action potentials, and the short-term plasticity characteristics during short, high frequency trains of action potentials. Understanding these relationships is important not only for healthy synapses, but also to better understand the pathophysiology of neuromuscular diseases. In particular, we are interested in Lambert-Eaton myasthenic syndrome (LEMS), an autoimmune disorder in which neurotransmitter release from the NMJ decreases, leading to severe muscle weakness. In LEMS, the reduced neurotransmission is traditionally thought to be caused by the antibody-mediated removal of presynaptic voltage-gated calcium channels. However, recent experimental data and AZ computer simulations have predicted that a disruption in the normally highly organized active zone structure, and perhaps autoantibodies to other presynaptic proteins, contribute significantly to pathological effects in the active zone and the characteristics of chemical transmitters.
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4
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Takikawa K, Nishimune H. Similarity and Diversity of Presynaptic Molecules at Neuromuscular Junctions and Central Synapses. Biomolecules 2022; 12:biom12020179. [PMID: 35204679 PMCID: PMC8961632 DOI: 10.3390/biom12020179] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 01/17/2022] [Accepted: 01/19/2022] [Indexed: 12/04/2022] Open
Abstract
Synaptic transmission is essential for controlling motor functions and maintaining brain functions such as walking, breathing, cognition, learning, and memory. Neurotransmitter release is regulated by presynaptic molecules assembled in active zones of presynaptic terminals. The size of presynaptic terminals varies, but the size of a single active zone and the types of presynaptic molecules are highly conserved among neuromuscular junctions (NMJs) and central synapses. Three parameters play an important role in the determination of neurotransmitter release properties at NMJs and central excitatory/inhibitory synapses: the number of presynaptic molecular clusters, the protein families of the presynaptic molecules, and the distance between presynaptic molecules and voltage-gated calcium channels. In addition, dysfunction of presynaptic molecules causes clinical symptoms such as motor and cognitive decline in patients with various neurological disorders and during aging. This review focuses on the molecular mechanisms responsible for the functional similarities and differences between excitatory and inhibitory synapses in the peripheral and central nervous systems, and summarizes recent findings regarding presynaptic molecules assembled in the active zone. Furthermore, we discuss the relationship between functional alterations of presynaptic molecules and dysfunction of NMJs or central synapses in diseases and during aging.
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Affiliation(s)
- Kenji Takikawa
- Laboratory of Neurobiology of Aging, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakaecho, Itabashi-ku, Tokyo 173-0015, Japan;
| | - Hiroshi Nishimune
- Laboratory of Neurobiology of Aging, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakaecho, Itabashi-ku, Tokyo 173-0015, Japan;
- Department of Applied Biological Science, Tokyo University of Agriculture and Technology, 3-8-1 Harumi-cho, Fuchu-shi, Tokyo 183-8538, Japan
- Correspondence: ; Tel.: +81-3-3964-3241
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5
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Ziemkiewicz N, Hilliard GM, Dunn AJ, Madsen J, Haas G, Au J, Genovese PC, Chauvin HM, West C, Paoli A, Garg K. Laminin-111-Enriched Fibrin Hydrogels Enhance Functional Muscle Regeneration Following Trauma. Tissue Eng Part A 2022; 28:297-311. [PMID: 34409846 DOI: 10.1089/ten.tea.2021.0096] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Volumetric muscle loss (VML) is the surgical or traumatic loss of skeletal muscle, which can cause loss of limb function or permanent disability. VML injuries overwhelms the endogenous regenerative capacity of skeletal muscle and results in poor functional healing outcomes. Currently, there are no approved tissue engineering treatments for VML injuries. In this study, fibrin hydrogels enriched with laminin-111 (LM-111; 50-450 μg/mL) were used for the treatment of VML of the tibialis anterior in a rat model. Treatment with fibrin hydrogel containing 450 μg/mL of LM-111 (FBN450) improved muscle regeneration following VML injury. FBN450 hydrogel treatment increased the relative proportion of contractile to fibrotic tissue as indicated by the myosin: collagen ratio on day 28 post-VML injury. FBN450 hydrogels also enhanced myogenic protein expression and increased the quantity of small to medium size myofibers (500-2000 μm2) as well as innervated myofibers. Improved contractile tissue deposition due to FBN450 hydrogel treatment resulted in a significant improvement (∼60%) in torque production at day 28 postinjury. Taken together, these results suggest that the acellular FBN450 hydrogels provide a promising therapeutic strategy for VML that is worthy of further investigation.
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Affiliation(s)
- Natalia Ziemkiewicz
- Department of Biomedical Engineering, Parks College of Engineering, Aviation and Technology, Saint Louis University, St. Louis, Missouri, USA
| | - Genevieve M Hilliard
- Department of Biomedical Engineering, Parks College of Engineering, Aviation and Technology, Saint Louis University, St. Louis, Missouri, USA
| | - Andrew J Dunn
- Department of Biomedical Engineering, Parks College of Engineering, Aviation and Technology, Saint Louis University, St. Louis, Missouri, USA
| | - Josh Madsen
- Department of Biomedical Engineering, Parks College of Engineering, Aviation and Technology, Saint Louis University, St. Louis, Missouri, USA
| | - Gabriel Haas
- Department of Biomedical Engineering, Parks College of Engineering, Aviation and Technology, Saint Louis University, St. Louis, Missouri, USA
| | - Jeffrey Au
- Department of Biomedical Engineering, Parks College of Engineering, Aviation and Technology, Saint Louis University, St. Louis, Missouri, USA
| | - Peter C Genovese
- Department of Biomedical Engineering, Parks College of Engineering, Aviation and Technology, Saint Louis University, St. Louis, Missouri, USA
| | - Hannah M Chauvin
- Department of Biomedical Engineering, Parks College of Engineering, Aviation and Technology, Saint Louis University, St. Louis, Missouri, USA
| | - Charles West
- Department of Biomedical Engineering, Parks College of Engineering, Aviation and Technology, Saint Louis University, St. Louis, Missouri, USA
| | - Allison Paoli
- Department of Biomedical Engineering, Parks College of Engineering, Aviation and Technology, Saint Louis University, St. Louis, Missouri, USA
| | - Koyal Garg
- Department of Biomedical Engineering, Parks College of Engineering, Aviation and Technology, Saint Louis University, St. Louis, Missouri, USA
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6
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Yang X, Annaert W. The Nanoscopic Organization of Synapse Structures: A Common Basis for Cell Communication. MEMBRANES 2021; 11:248. [PMID: 33808285 PMCID: PMC8065904 DOI: 10.3390/membranes11040248] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Revised: 03/26/2021] [Accepted: 03/27/2021] [Indexed: 11/16/2022]
Abstract
Synapse structures, including neuronal and immunological synapses, can be seen as the plasma membrane contact sites between two individual cells where information is transmitted from one cell to the other. The distance between the two plasma membranes is only a few tens of nanometers, but these areas are densely populated with functionally different proteins, including adhesion proteins, receptors, and transporters. The narrow space between the two plasma membranes has been a barrier for resolving the synaptic architecture due to the diffraction limit in conventional microscopy (~250 nm). Various advanced super-resolution microscopy techniques, such as stimulated emission depletion (STED), structured illumination microscopy (SIM), and single-molecule localization microscopy (SMLM), bypass the diffraction limit and provide a sub-diffraction-limit resolving power, ranging from 10 to 100 nm. The studies using super-resolution microscopy have revealed unprecedented details of the nanoscopic organization and dynamics of synaptic molecules. In general, most synaptic proteins appear to be heterogeneously distributed and form nanodomains at the membranes. These nanodomains are dynamic functional units, playing important roles in mediating signal transmission through synapses. Herein, we discuss our current knowledge on the super-resolution nanoscopic architecture of synapses and their functional implications, with a particular focus on the neuronal synapses and immune synapses.
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Affiliation(s)
| | - Wim Annaert
- VIB Center for Brain and Disease Research and KU Leuven, Department of Neurosciences, Gasthuisberg, B-3000 Leuven, Belgium;
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7
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Li L, Li H, Wang L, Bu T, Liu S, Mao B, Cheng CY. A local regulatory network in the testis mediated by laminin and collagen fragments that supports spermatogenesis. Crit Rev Biochem Mol Biol 2021; 56:236-254. [PMID: 33761828 DOI: 10.1080/10409238.2021.1901255] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
It is almost five decades since the discovery of the hypothalamic-pituitary-testicular axis. This refers to the hormonal axis that connects the hypothalamus, pituitary gland and testes, which in turn, regulates the production of spermatozoa through spermatogenesis in the seminiferous tubules, and testosterone through steroidogenesis by Leydig cells in the interstitium, of the testes. Emerging evidence has demonstrated the presence of a regulatory network across the seminiferous epithelium utilizing bioactive molecules produced locally at specific domains of the epithelium. Studies have shown that biologically active fragments are produced from structural laminin and collagen chains in the basement membrane. Additionally, bioactive peptides are also produced locally in non-basement membrane laminin chains at the Sertoli-spermatid interface known as apical ectoplasmic specialization (apical ES, a testis-specific actin-based anchoring junction type). These bioactive peptides are derived from structural laminins and/or collagens at the corresponding sites through proteolytic cleavage by matrix metalloproteinases (MMPs). They in turn serve as autocrine and/or paracrine factors to modulate and coordinate cellular events across the epithelium by linking the apical and basal compartments, the apical and basal ES, the blood-testis barrier (BTB), and the basement membrane of the tunica propria. The cellular events supported by these bioactive peptides/fragments include the release of spermatozoa at spermiation, remodeling of the immunological barrier to facilitate the transport of preleptotene spermatocytes across the BTB, and the transport of haploid spermatids across the epithelium to support spermiogenesis. In this review, we critically evaluate these findings. Our goal is to identify research areas that deserve attentions in future years. The proposed research also provides the much needed understanding on the biology of spermatogenesis supported by a local network of regulatory biomolecules.
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Affiliation(s)
- Linxi Li
- The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, China.,The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, New York, NY, USA
| | - Huitao Li
- The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, China.,The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, New York, NY, USA
| | - Lingling Wang
- The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, China.,The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, New York, NY, USA
| | - Tiao Bu
- The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, China
| | - Shiwen Liu
- The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, China.,The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, New York, NY, USA
| | - Baiping Mao
- The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, China.,The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, New York, NY, USA
| | - C Yan Cheng
- The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, China.,The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, New York, NY, USA
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Yuzuriha A, Nakamura S, Sugimoto N, Kihara S, Nakagawa M, Yamamoto T, Sekiguchi K, Eto K. Extracellular laminin regulates hematopoietic potential of pluripotent stem cells through integrin β1-ILK-β-catenin-JUN axis. Stem Cell Res 2021; 53:102287. [PMID: 33813173 DOI: 10.1016/j.scr.2021.102287] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 03/08/2021] [Accepted: 03/09/2021] [Indexed: 12/21/2022] Open
Abstract
Recombinant matrices have enabled feeder cell-free maintenance cultures of human pluripotent stem cells (hPSCs), with laminin 511-E8 fragment (LM511-E8) being widely used. However, we herein report that hPSCs maintained on LM511-E8 resist differentiating to multipotent hematopoietic progenitor cells (HPCs), unlike hPSCs maintained on LM421-E8 or LM121-E8. The latter two LM-E8s bound weakly to hPSCs compared with LM511-E8 and activated the canonical Wnt/β-catenin signaling pathway. Moreover, the extracellular LM-E8-dependent preferential hematopoiesis was associated with a higher expression of integrin β1 (ITGB1) and downstream integrin-linked protein kinase (ILK), β-catenin and phosphorylated JUN. Accordingly, the lower coating concentration of LM511-E8 or addition of a Wnt/β-catenin signaling activator, CHIR99021, facilitated higher HPC yield. In contrast, the inhibition of ILK, Wnt or JNK by inhibitors or mRNA knockdown suppressed the HPC yield. These findings suggest that extracellular laminin scaffolds modulate the hematopoietic differentiation potential of hPSCs by activating the ITGB1-ILK-β-catenin-JUN axis at the undifferentiated stage. Finally, the combination of low-concentrated LM511-E8 and a revised hPSC-sac method, which adds bFGF, SB431542 and heparin to the conventional method, enabled a higher yield of HPCs and higher rate for definitive hematopoiesis, suggesting a useful protocol for obtaining differentiated hematopoietic cells from hPSCs in general.
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Affiliation(s)
- Akinori Yuzuriha
- Department of Clinical Application, CiRA, Kyoto University, Kyoto, Japan
| | - Sou Nakamura
- Department of Clinical Application, CiRA, Kyoto University, Kyoto, Japan
| | - Naoshi Sugimoto
- Department of Clinical Application, CiRA, Kyoto University, Kyoto, Japan
| | - Shunsuke Kihara
- Department of Fundamental Cell Technology, CiRA, Kyoto University, Kyoto, Japan
| | - Masato Nakagawa
- Department of Life Science Frontiers, CiRA, Kyoto University, Kyoto, Japan
| | - Takuya Yamamoto
- Department of Life Science Frontiers, CiRA, Kyoto University, Kyoto, Japan; Institute for the Advanced Study of Human Biology (WPI-ASHBi), Kyoto University, Kyoto 606-8501, Japan; AMED-CREST, AMED 1-7-1 Otemachi, Chiyodaku, Tokyo 100-0004, Japan
| | - Kiyotoshi Sekiguchi
- Division of Matrixome Research and Application, Institute for Protein Research, Osaka University, Suita, Japan
| | - Koji Eto
- Department of Clinical Application, CiRA, Kyoto University, Kyoto, Japan; Department of Regenerative Medicine, Chiba University Graduate School of Medicine, Chiba, Japan.
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9
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Badawi Y, Nishimune H. Impairment Mechanisms and Intervention Approaches for Aged Human Neuromuscular Junctions. Front Mol Neurosci 2020; 13:568426. [PMID: 33328881 PMCID: PMC7717980 DOI: 10.3389/fnmol.2020.568426] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 10/16/2020] [Indexed: 12/19/2022] Open
Abstract
The neuromuscular junction (NMJ) is a chemical synapse formed between a presynaptic motor neuron and a postsynaptic muscle cell. NMJs in most vertebrate species share many essential features; however, some differences distinguish human NMJs from others. This review will describe the pre- and postsynaptic structures of human NMJs and compare them to NMJs of laboratory animals. We will focus on age-dependent declines in function and changes in the structure of human NMJs. Furthermore, we will describe insights into the aging process revealed from mouse models of accelerated aging. In addition, we will compare aging phenotypes to other human pathologies that cause impairments of pre- and postsynaptic structures at NMJs. Finally, we will discuss potential intervention approaches for attenuating age-related NMJ dysfunction and sarcopenia in humans.
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Affiliation(s)
- Yomna Badawi
- Department of Anatomy and Cell Biology, University of Kansas School of Medicine, Kansas City, KS, United States
| | - Hiroshi Nishimune
- Department of Anatomy and Cell Biology, University of Kansas School of Medicine, Kansas City, KS, United States.,Neurobiology of Aging, Tokyo Metropolitan Institute of Gerontology, Itabashi, Japan
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10
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Song R, Zhang L. Cardiac ECM: Its Epigenetic Regulation and Role in Heart Development and Repair. Int J Mol Sci 2020; 21:ijms21228610. [PMID: 33203135 PMCID: PMC7698074 DOI: 10.3390/ijms21228610] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Revised: 11/07/2020] [Accepted: 11/13/2020] [Indexed: 12/14/2022] Open
Abstract
The extracellular matrix (ECM) is the non-cellular component in the cardiac microenvironment, and serves essential structural and regulatory roles in establishing and maintaining tissue architecture and cellular function. The patterns of molecular and biochemical ECM alterations in developing and adult hearts depend on the underlying injury type. In addition to exploring how the ECM regulates heart structure and function in heart development and repair, this review conducts an inclusive discussion of recent developments in the role, function, and epigenetic guidelines of the ECM. Moreover, it contributes to the development of new therapeutics for cardiovascular disease.
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Affiliation(s)
- Rui Song
- Correspondence: (R.S.); (L.Z.); Tel.: +1-909-558-4325 (R.S. & L.Z.)
| | - Lubo Zhang
- Correspondence: (R.S.); (L.Z.); Tel.: +1-909-558-4325 (R.S. & L.Z.)
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11
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Cao M, Koneczny I, Vincent A. Myasthenia Gravis With Antibodies Against Muscle Specific Kinase: An Update on Clinical Features, Pathophysiology and Treatment. Front Mol Neurosci 2020; 13:159. [PMID: 32982689 PMCID: PMC7492727 DOI: 10.3389/fnmol.2020.00159] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Accepted: 08/03/2020] [Indexed: 12/24/2022] Open
Abstract
Muscle Specific Kinase myasthenia gravis (MuSK-MG) is an autoimmune disease that impairs neuromuscular transmission leading to generalized muscle weakness. Compared to the more common myasthenia gravis with antibodies against the acetylcholine receptor (AChR), MuSK-MG affects mainly the bulbar and respiratory muscles, with more frequent and severe myasthenic crises. Treatments are usually less effective with the need for prolonged, high doses of steroids and other immunosuppressants to control symptoms. Under physiological condition, MuSK regulates a phosphorylation cascade which is fundamental for the development and maintenance of postsynaptic AChR clusters at the neuromuscular junction (NMJ). Agrin, secreted by the motor nerve terminal into the synaptic cleft, binds to low density lipoprotein receptor-related protein 4 (LRP4) which activates MuSK. In MuSK-MG, monovalent MuSK-IgG4 autoantibodies block MuSK-LRP4 interaction preventing MuSK activation and leading to the dispersal of AChR clusters. Lower levels of divalent MuSK IgG1, 2, and 3 antibody subclasses are also present but their contribution to the pathogenesis of the disease remains controversial. This review aims to provide a detailed update on the epidemiological and clinical features of MuSK-MG, focusing on the pathophysiological mechanisms and the latest indications regarding the efficacy and safety of different treatment options.
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Affiliation(s)
- Michelangelo Cao
- Nuffield Department of Clinical Neurosciences, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | - Inga Koneczny
- Division of Neuropathology and Neurochemistry, Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Angela Vincent
- Nuffield Department of Clinical Neurosciences, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
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12
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Florkowska A, Meszka I, Zawada M, Legutko D, Proszynski TJ, Janczyk-Ilach K, Streminska W, Ciemerych MA, Grabowska I. Pax7 as molecular switch regulating early and advanced stages of myogenic mouse ESC differentiation in teratomas. Stem Cell Res Ther 2020; 11:238. [PMID: 32552916 PMCID: PMC7301568 DOI: 10.1186/s13287-020-01742-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 05/15/2020] [Accepted: 05/25/2020] [Indexed: 12/17/2022] Open
Abstract
Background Pluripotent stem cells present the ability to self-renew and undergo differentiation into any cell type building an organism. Importantly, a lot of evidence on embryonic stem cell (ESC) differentiation comes from in vitro studies. However, ESCs cultured in vitro do not necessarily behave as cells differentiating in vivo. For this reason, we used teratomas to study early and advanced stages of in vivo ESC myogenic differentiation and the role of Pax7 in this process. Pax7 transcription factor plays a crucial role in the formation and differentiation of skeletal muscle precursor cells during embryonic development. It controls the expression of other myogenic regulators and also acts as an anti-apoptotic factor. It is also involved in the formation and maintenance of satellite cell population. Methods In vivo approach we used involved generation and analysis of pluripotent stem cell-derived teratomas. Such model allows to analyze early and also terminal stages of tissue differentiation, for example, terminal stages of myogenesis, including the formation of innervated and vascularized mature myofibers. Results We determined how the lack of Pax7 function affects the generation of different myofiber types. In Pax7−/− teratomas, the skeletal muscle tissue occupied significantly smaller area, as compared to Pax7+/+ ones. The proportion of myofibers expressing Myh3 and Myh2b did not differ between Pax7+/+ and Pax7−/− teratomas. However, the area of Myh7 and Myh2a myofibers was significantly lower in Pax7−/− ones. Molecular characteristic of skeletal muscles revealed that the levels of mRNAs coding Myh isoforms were significantly lower in Pax7−/− teratomas. The level of mRNAs encoding Pax3 was significantly higher, while the expression of Nfix, Eno3, Mck, Mef2a, and Itga7 was significantly lower in Pax7−/− teratomas, as compared to Pax7+/+ ones. We proved that the number of satellite cells in Pax7−/− teratomas was significantly reduced. Finally, analysis of neuromuscular junction localization in samples prepared with the iDISCO method confirmed that the organization of neuromuscular junctions in Pax7−/− teratomas was impaired. Conclusions Pax7−/− ESCs differentiate in vivo to embryonic myoblasts more readily than Pax7+/+ cells. In the absence of functional Pax7, initiation of myogenic differentiation is facilitated, and as a result, the expression of mesoderm embryonic myoblast markers is upregulated. However, in the absence of functional Pax7 neuromuscular junctions, formation is abnormal, what results in lower differentiation potential of Pax7−/− ESCs during advanced stages of myogenesis.
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Affiliation(s)
- Anita Florkowska
- Department of Cytology, Institute of Developmental Biology and Biomedical Sciences, Faculty of Biology, University of Warsaw, Warsaw, Poland
| | - Igor Meszka
- Department of Cytology, Institute of Developmental Biology and Biomedical Sciences, Faculty of Biology, University of Warsaw, Warsaw, Poland
| | - Magdalena Zawada
- Department of Cytology, Institute of Developmental Biology and Biomedical Sciences, Faculty of Biology, University of Warsaw, Warsaw, Poland
| | - Diana Legutko
- Department of Cytology, Institute of Developmental Biology and Biomedical Sciences, Faculty of Biology, University of Warsaw, Warsaw, Poland.,Laboratory of Neurobiology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
| | - Tomasz J Proszynski
- Laboratory of Synaptogenesis, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland.,Present Address: Lukasiewicz Research Network - PORT Polish Center for Technology Development, Wroclaw, Poland
| | - Katarzyna Janczyk-Ilach
- Department of Cytology, Institute of Developmental Biology and Biomedical Sciences, Faculty of Biology, University of Warsaw, Warsaw, Poland
| | - Wladyslawa Streminska
- Department of Cytology, Institute of Developmental Biology and Biomedical Sciences, Faculty of Biology, University of Warsaw, Warsaw, Poland
| | - Maria A Ciemerych
- Department of Cytology, Institute of Developmental Biology and Biomedical Sciences, Faculty of Biology, University of Warsaw, Warsaw, Poland
| | - Iwona Grabowska
- Department of Cytology, Institute of Developmental Biology and Biomedical Sciences, Faculty of Biology, University of Warsaw, Warsaw, Poland.
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13
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Yan Y, Yu H, Sun L, Liu H, Wang C, Wei X, Song F, Li H, Ge H, Qian H, Li X, Tang X, Liu P. Laminin α4 overexpression in the anterior lens capsule may contribute to the senescence of human lens epithelial cells in age-related cataract. Aging (Albany NY) 2020; 11:2699-2723. [PMID: 31076560 PMCID: PMC6535067 DOI: 10.18632/aging.101943] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 04/27/2019] [Indexed: 12/16/2022]
Abstract
Senescence is a leading cause of age-related cataract (ARC). The current study indicated that the senescence-associated protein, p53, total laminin (LM), LMα4, and transforming growth factor-beta1 (TGF-β1) in the cataractous anterior lens capsules (ALCs) increase with the grades of ARC. In cataractous ALCs, patient age, total LM, LMα4, TGF-β1, were all positively correlated with p53. In lens epithelial cell (HLE B-3) senescence models, matrix metalloproteinase-9 (MMP-9) alleviated senescence by decreasing the expression of total LM and LMα4; TGF-β1 induced senescence by increasing the expression of total LM and LMα4. Furthermore, MMP-9 silencing increased p-p38 and LMα4 expression; anti-LMα4 globular domain antibody alleviated senescence by decreasing the expression of p-p38 and LMα4; pharmacological inhibition of p38 MAPK signaling alleviated senescence by decreasing the expression of LMα4. Finally, in cataractous ALCs, positive correlations were found between LMα4 and total LM, as well as between LMα4 and TGF-β1. Taken together, our results implied that the elevated LMα4, which was possibly caused by the decreased MMP-9, increased TGF-β1 and activated p38 MAPK signaling during senescence, leading to the development of ARC. LMα4 and its regulatory factors show potential as targets for drug development for prevention and treatment of ARC.
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Affiliation(s)
- Yu Yan
- Eye Hospital, First Affiliated Hospital, Harbin Medical University, Harbin, 150001, China.,Department of Pharmacology, College of Pharmacy, Harbin Medical University, and Heilongjiang Academy of Medical Sciences, Harbin, 150081, China
| | - Haiyang Yu
- Eye Hospital, First Affiliated Hospital, Harbin Medical University, Harbin, 150001, China.,Department of Pharmacology, College of Pharmacy, Harbin Medical University, and Heilongjiang Academy of Medical Sciences, Harbin, 150081, China
| | - Liyao Sun
- Eye Hospital, First Affiliated Hospital, Harbin Medical University, Harbin, 150001, China.,Department of Pharmacology, College of Pharmacy, Harbin Medical University, and Heilongjiang Academy of Medical Sciences, Harbin, 150081, China
| | - Hanruo Liu
- Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Science Key Lab, Beijing, 100000, China
| | - Chao Wang
- Eye Hospital, First Affiliated Hospital, Harbin Medical University, Harbin, 150001, China.,Department of Pharmacology, College of Pharmacy, Harbin Medical University, and Heilongjiang Academy of Medical Sciences, Harbin, 150081, China
| | - Xi Wei
- Eye Hospital, First Affiliated Hospital, Harbin Medical University, Harbin, 150001, China.,Department of Pharmacology, College of Pharmacy, Harbin Medical University, and Heilongjiang Academy of Medical Sciences, Harbin, 150081, China
| | - Fanqian Song
- Eye Hospital, First Affiliated Hospital, Harbin Medical University, Harbin, 150001, China.,Department of Pharmacology, College of Pharmacy, Harbin Medical University, and Heilongjiang Academy of Medical Sciences, Harbin, 150081, China
| | - Hulun Li
- Department of Neurobiology, Neurobiology Key Laboratory, Harbin Medical University, Harbin, 150081, China
| | - Hongyan Ge
- Eye Hospital, First Affiliated Hospital, Harbin Medical University, Harbin, 150001, China
| | - Hua Qian
- Department of Pharmacology, College of Pharmacy, Harbin Medical University, and Heilongjiang Academy of Medical Sciences, Harbin, 150081, China
| | - Xiaoguang Li
- Department of Pharmacology, College of Pharmacy, Harbin Medical University, and Heilongjiang Academy of Medical Sciences, Harbin, 150081, China
| | - Xianling Tang
- Eye Hospital, First Affiliated Hospital, Harbin Medical University, Harbin, 150001, China
| | - Ping Liu
- Eye Hospital, First Affiliated Hospital, Harbin Medical University, Harbin, 150001, China
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14
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Multiple MuSK signaling pathways and the aging neuromuscular junction. Neurosci Lett 2020; 731:135014. [PMID: 32353380 DOI: 10.1016/j.neulet.2020.135014] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 04/23/2020] [Accepted: 04/24/2020] [Indexed: 12/16/2022]
Abstract
The neuromuscular junction (NMJ) is the vehicle for fast, reliable and robust communication between motor neuron and muscle. The unparalleled accessibility of this synapse to morphological, electrophysiological and genetic analysis has yielded an in depth understanding of many molecular components mediating its formation, maturation and stability. However, key questions surrounding the signaling pathways mediating these events and how they play out across the lifetime of the synapse remain unanswered. Such information is critical since the NMJ is necessary for normal movement and is compromised in several settings including myasthenia gravis, amyotrophic lateral sclerosis (ALS), spinal muscular atrophy (SMA), muscular dystrophy, sarcopenia and aging. Muscle specific kinase (MuSK) is a central player in most if not all contexts of NMJ formation and stability. However, elucidating the function of this receptor in this range of settings is challenging since MuSK participates in at least three signaling pathways: as a tyrosine kinase-dependent receptor for agrin-LRP4 and Wnts; and, as a kinase-independent BMP co-receptor. Here we focus on NMJ stability during aging and discuss open questions regarding the molecular mechanisms that govern active maintenance of the NMJ, with emphasis on MuSK and the potential role of its multiple signaling contexts.
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15
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Perisynaptic schwann cells - The multitasking cells at the developing neuromuscular junctions. Semin Cell Dev Biol 2020; 104:31-38. [PMID: 32147379 DOI: 10.1016/j.semcdb.2020.02.011] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Revised: 02/27/2020] [Accepted: 02/28/2020] [Indexed: 12/27/2022]
Abstract
Neuromuscular junctions (NMJs) are specialized synapses in the peripheral nervous system that allow the transmission of neuronal impulses to skeletal muscles for their contraction. Due to its size and accessibility, the NMJ is a commonly used model for studying basic principles of synapse organization and function. Similar to synapses in the central nervous system, NMJs are composed of presynaptic axonal terminals, the postsynaptic machinery formed at the membrane of the muscle fibers, and the synapse-associated glial cells. The special glial cells at the NMJs are called terminal Schwann cells or perisynaptic Schwann cells (PSCs). Decades of studies on the NMJ, as well as the most recent discoveries, have revealed multiple functions for PSCs at different stages of synaptic formation, maintenance, and disassembly. This review summarizes major observations in the field.
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16
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MMP-mediated modulation of ECM environment during axonal growth and NMJ development. Neurosci Lett 2020; 724:134822. [PMID: 32061716 DOI: 10.1016/j.neulet.2020.134822] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Revised: 01/31/2020] [Accepted: 02/04/2020] [Indexed: 12/19/2022]
Abstract
Motor neurons, skeletal muscles, and perisynaptic Schwann cells interact with extracellular matrix (ECM) to form the tetrapartite synapse in the peripheral nervous system. Dynamic remodeling of ECM composition is essential to diversify its functions for distinct cellular processes during neuromuscular junction (NMJ) development. In this review, we give an overview of the proteolytic regulation of ECM proteins, particularly by secreted and membrane-type matrix metalloproteinases (MMPs), in axonal growth and NMJ development. It is suggested that MMP-2, MMP-9, and membrane type 1-MMP (MT1-MMP) promote axonal outgrowth and regeneration upon injury by clearing the glial scars at the lesion site. In addition, these MMPs also play roles in neuromuscular synaptogenesis, ranging from spontaneous formation of synaptic specializations to activity-dependent synaptic elimination, via proteolytic cleavage or degradation of growth factors, neurotrophic factors, and ECM molecules. For instance, secreted MMP-3 has been known to cleave agrin, the main postsynaptic differentiation inducer, further highlighting the importance of MMPs in NMJ formation and maintenance. Furthermore, the increased level of several MMPs in myasthenia gravis (MG) patient suggest the pathophysiological mechanisms of MMP-mediated proteolytic degradation in MG pathogenesis. Finally, we speculate on potential major future directions for studying the regulatory functions of MMP-mediated ECM remodeling in axonal growth and NMJ development.
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17
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Suzuki N, Hyodo M, Hayashi C, Mabuchi Y, Sekimoto K, Onchi C, Sekiguchi K, Akazawa C. Laminin α2, α4, and α5 Chains Positively Regulate Migration and Survival of Oligodendrocyte Precursor Cells. Sci Rep 2019; 9:19882. [PMID: 31882770 PMCID: PMC6934537 DOI: 10.1038/s41598-019-56488-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Accepted: 12/11/2019] [Indexed: 12/31/2022] Open
Abstract
In the developing central nervous system (CNS), oligodendrocyte precursor cells (OPCs) migrate along blood vessels and are widely distributed in the CNS. Meanwhile, OPCs require survival factors from the extracellular microenvironment. In other tissues, laminins, heterotrimetric (αβγ) extracellular matrix proteins, promote cell migration and survival. However, the expression pattern and functions of laminins in OPC development remain poorly understood. In the present study, we first investigated the expression of laminin α chains, which bind to cell surface receptors such as integrins, in the postnatal murine brain. We found that laminin α1, α2, α4, and α5 chains were expressed around blood vessels and OPCs attached the laminin α chain-positive vessels. We then evaluated the effect of these laminins on OPCs activity using recombinant laminin E8s (LME8s) that are minimally active fragments of the laminin isoforms. OPCs attached on LM211E8, LM411E8, and LM511E8, containing laminin α2, α4, and α5 chains, respectively, through integrin β1. Further, these three LME8s promoted migration of OPCs, and OPC survival was prolonged on either LM411E8 or LM511E8 via the activation of focal adhesion kinase. Together, our findings suggest that laminins expressed surrounding blood vessels positively regulate migration and survival of OPCs through the integrin β1-FAK pathway.
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Affiliation(s)
- Nobuharu Suzuki
- Department of Molecular and Cellular Biology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan. .,Department of Biochemistry and Biophysics, Graduate School of Health Care Sciences, TMDU, Tokyo, Japan.
| | - Mai Hyodo
- Department of Biochemistry and Biophysics, Graduate School of Health Care Sciences, TMDU, Tokyo, Japan
| | - Chikako Hayashi
- Department of Molecular and Cellular Biology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan.,Department of Biochemistry and Biophysics, Graduate School of Health Care Sciences, TMDU, Tokyo, Japan
| | - Yo Mabuchi
- Department of Biochemistry and Biophysics, Graduate School of Health Care Sciences, TMDU, Tokyo, Japan.,Department of Biochemistry and Biophysics, Graduate School of Medical and Dental Sciences, TMDU, Tokyo, Japan
| | - Kaori Sekimoto
- Department of Biochemistry and Biophysics, Graduate School of Health Care Sciences, TMDU, Tokyo, Japan
| | - Chinami Onchi
- Department of Molecular and Cellular Biology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Kiyotoshi Sekiguchi
- Division of Matrixome Research and Application, Institute for Protein Research, Osaka University, Suita, Osaka, Japan
| | - Chihiro Akazawa
- Department of Biochemistry and Biophysics, Graduate School of Health Care Sciences, TMDU, Tokyo, Japan. .,Department of Biochemistry and Biophysics, Graduate School of Medical and Dental Sciences, TMDU, Tokyo, Japan.
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18
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Wu S, Yan M, Ge R, Cheng CY. Crosstalk between Sertoli and Germ Cells in Male Fertility. Trends Mol Med 2019; 26:215-231. [PMID: 31727542 DOI: 10.1016/j.molmed.2019.09.006] [Citation(s) in RCA: 81] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 08/16/2019] [Accepted: 09/13/2019] [Indexed: 12/14/2022]
Abstract
Spermatogenesis is supported by intricate crosstalk between Sertoli cells and germ cells including spermatogonia, spermatocytes, haploid spermatids, and spermatozoa, which takes place in the epithelium of seminiferous tubules. Sertoli cells, also known as 'mother' or 'nurse' cells, provide nutrients, paracrine factors, cytokines, and other biomolecules to support germ cell development. Sertoli cells facilitate the generation of several biologically active peptides, which include F5-, noncollagenous 1 (NC1)-, and laminin globular (LG)3/4/5-peptide, to modulate cellular events across the epithelium. Here, we critically evaluate the involvement of these peptides in facilitating crosstalk between Sertoli and germ cells to support spermatogenesis and thus fertility. Modulating or mimicking the activity of F5-, NC1-, and LG3/4/5-peptide could be used to enhance the transport across the blood-testis barrier (BTB) of contraceptive drugs or to treat male infertility.
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Affiliation(s)
- Siwen Wu
- The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, Zhejiang 325027, China; The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, 1230 York Avenue, New York, NY 10065, USA
| | - Ming Yan
- Jiangsu Key Laboratory of Drug Screening, China Pharmaceutical University, Nanjing, Jiangsu 210009, China
| | - Renshan Ge
- The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
| | - C Yan Cheng
- The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, Zhejiang 325027, China; The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, 1230 York Avenue, New York, NY 10065, USA.
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19
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Kölbel H, Hathazi D, Jennings M, Horvath R, Roos A, Schara U. Identification of Candidate Protein Markers in Skeletal Muscle of Laminin-211-Deficient CMD Type 1A-Patients. Front Neurol 2019; 10:470. [PMID: 31133972 PMCID: PMC6514157 DOI: 10.3389/fneur.2019.00470] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Accepted: 04/17/2019] [Indexed: 12/11/2022] Open
Abstract
Laminin-211 deficiency leads to the most common form of congenital muscular dystrophy in childhood, MDC1A. The clinical picture is characterized by severe muscle weakness, brain abnormalities and delayed motor milestones defining MDC1A as one of the most severe forms of congenital muscular diseases. Although the molecular genetic basis of this neurological disease is well-known and molecular studies of mouse muscle and human cultured muscle cells allowed first insights into the underlying pathophysiology, the definition of marker proteins in human vulnerable tissue such as skeletal muscle is still lacking. To systematically address this need, we analyzed the proteomic signature of laminin-211-deficient vastus muscle derived from four patients and identified 86 proteins (35 were increased and 51 decreased) as skeletal muscle markers and verified paradigmatic findings in a total of two further MDC1A muscle biopsies. Functions of proteins suggests fibrosis but also hints at altered synaptic transmission and accords with central nervous system alterations as part of the clinical spectrum of MDC1A. In addition, a profound mitochondrial vulnerability of the laminin-211-deficient muscle is indicated and also altered abundances of other proteins support the concept that metabolic alterations could be novel mechanisms that underline MDC1A and might constitute therapeutic targets. Intersection of our data with the proteomic signature of murine laminin-211-deficient gastrocnemius and diaphragm allowed the definition of nine common vulnerable proteins representing potential tissue markers.
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Affiliation(s)
- Heike Kölbel
- Department of Pediatric Neurology, Developmental Neurology and Social Pediatrics, University of Duisburg-Essen, Essen, Germany
| | - Denisa Hathazi
- Leibniz-Institut für Analytische Wissenschaften -ISAS- e.V., Dortmund, Germany.,Department of Clinical Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Matthew Jennings
- Department of Clinical Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Rita Horvath
- Department of Clinical Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Andreas Roos
- Department of Pediatric Neurology, Developmental Neurology and Social Pediatrics, University of Duisburg-Essen, Essen, Germany.,Leibniz-Institut für Analytische Wissenschaften -ISAS- e.V., Dortmund, Germany
| | - Ulrike Schara
- Department of Pediatric Neurology, Developmental Neurology and Social Pediatrics, University of Duisburg-Essen, Essen, Germany
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20
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Heikkinen A, Härönen H, Norman O, Pihlajaniemi T. Collagen XIII and Other ECM Components in the Assembly and Disease of the Neuromuscular Junction. Anat Rec (Hoboken) 2019; 303:1653-1663. [PMID: 30768864 DOI: 10.1002/ar.24092] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 08/17/2018] [Accepted: 09/27/2018] [Indexed: 12/15/2022]
Abstract
Alongside playing structural roles, the extracellular matrix (ECM) acts as an interaction platform for cellular homeostasis, organ development, and maintenance. The necessity of the ECM is highlighted by the diverse, sometimes very serious diseases that stem from defects in its components. The neuromuscular junction (NMJ) is a large peripheral motor synapse differing from its central counterparts through the ECM included at the synaptic cleft. Such synaptic basal lamina (BL) is specialized to support NMJ establishment, differentiation, maturation, stabilization, and function and diverges in molecular composition from the extrasynaptic ECM. Mutations, toxins, and autoantibodies may compromise NMJ integrity and function, thereby leading to congenital myasthenic syndromes (CMSs), poisoning, and autoimmune diseases, respectively, and all these conditions may involve synaptic ECM molecules. With neurotransmission degraded or blocked, muscle function is impaired or even prevented. At worst, this can be fatal. The article reviews the synaptic BL composition required for assembly and function of the NMJ molecular machinery through the lens of studies primarily with mouse models but also with human patients. In-depth focus is given to collagen XIII, a postsynaptic-membrane-spanning but also shed ECM protein that in recent years has been revealed to be a significant component for the NMJ. Its deficiency in humans causes CMS, and autoantibodies against it have been recognized in autoimmune myasthenia gravis. Mouse models have exposed numerous details that appear to recapitulate human NMJ phenotypes relatively faithfully and thereby can be readily used to generate information necessary for understanding and ultimately treating human diseases. Anat Rec, 2019. © 2019 Wiley Periodicals, Inc.
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Affiliation(s)
- Anne Heikkinen
- Oulu Center for Cell-Matrix Research, Biocenter Oulu, Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | - Heli Härönen
- Oulu Center for Cell-Matrix Research, Biocenter Oulu, Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | - Oula Norman
- Oulu Center for Cell-Matrix Research, Biocenter Oulu, Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | - Taina Pihlajaniemi
- Oulu Center for Cell-Matrix Research, Biocenter Oulu, Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
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21
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Cescon M, Gregorio I, Eiber N, Borgia D, Fusto A, Sabatelli P, Scorzeto M, Megighian A, Pegoraro E, Hashemolhosseini S, Bonaldo P. Collagen VI is required for the structural and functional integrity of the neuromuscular junction. Acta Neuropathol 2018; 136:483-499. [PMID: 29752552 DOI: 10.1007/s00401-018-1860-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 04/30/2018] [Accepted: 05/01/2018] [Indexed: 12/20/2022]
Abstract
The synaptic cleft of the neuromuscular junction (NMJ) consists of a highly specialized extracellular matrix (ECM) involved in synapse maturation, in the juxtaposition of pre- to post-synaptic areas, and in ensuring proper synaptic transmission. Key components of synaptic ECM, such as collagen IV, perlecan and biglycan, are binding partners of one of the most abundant ECM protein of skeletal muscle, collagen VI (ColVI), previously never linked to NMJ. Here, we demonstrate that ColVI is itself a component of this specialized ECM and that it is required for the structural and functional integrity of NMJs. In vivo, ColVI deficiency causes fragmentation of acetylcholine receptor (AChR) clusters, with abnormal expression of NMJ-enriched proteins and re-expression of fetal AChRγ subunit, both in Col6a1 null mice and in patients affected by Ullrich congenital muscular dystrophy (UCMD), the most severe form of ColVI-related myopathies. Ex vivo muscle preparations from ColVI null mice revealed altered neuromuscular transmission, with electrophysiological defects and decreased safety factor (i.e., the excess current generated in response to a nerve impulse over that required to reach the action potential threshold). Moreover, in vitro studies in differentiated C2C12 myotubes showed the ability of ColVI to induce AChR clustering and synaptic gene expression. These findings reveal a novel role for ColVI at the NMJ and point to the involvement of NMJ defects in the etiopathology of ColVI-related myopathies.
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22
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Omar MH, Kerrisk Campbell M, Xiao X, Zhong Q, Brunken WJ, Miner JH, Greer CA, Koleske AJ. CNS Neurons Deposit Laminin α5 to Stabilize Synapses. Cell Rep 2018; 21:1281-1292. [PMID: 29091766 PMCID: PMC5776391 DOI: 10.1016/j.celrep.2017.10.028] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 09/21/2017] [Accepted: 10/08/2017] [Indexed: 11/28/2022] Open
Abstract
Synapses in the developing brain are structurally dynamic but become stable by early adulthood. We demonstrate here that an α5-subunit-containing laminin stabilizes synapses during this developmental transition. Hippocampal neurons deposit laminin α5 at synapses during adolescence as connections stabilize. Disruption of laminin α5 in neurons causes dramatic fluctuations in dendritic spine head size that can be rescued by exogenous α5-containing laminin. Conditional deletion of laminin α5 in vivo increases dendritic spine size and leads to an age-dependent loss of synapses accompanied by behavioral defects. Remaining synapses have larger postsynaptic densities and enhanced neurotransmission. Finally, we provide evidence that laminin α5 acts through an integrin α3β1-Abl2 kinase-p190RhoGAP signaling cascade and partners with laminin β2 to regulate dendritic spine density and behavior. Together, our results identify laminin α5 as a stabilizer of dendritic spines and synapses in the brain and elucidate key cellular and molecular mechanisms by which it acts.
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Affiliation(s)
- Mitchell H Omar
- Interdepartmental Neuroscience Program, Yale University, New Haven, CT 06510, USA; Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06510, USA
| | - Meghan Kerrisk Campbell
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06510, USA
| | - Xiao Xiao
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06510, USA
| | - Qiaonan Zhong
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06510, USA
| | - William J Brunken
- Department of Ophthalmology, Upstate Medical University, Syracuse, NY 13202, USA
| | - Jeffrey H Miner
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Charles A Greer
- Interdepartmental Neuroscience Program, Yale University, New Haven, CT 06510, USA; Department of Neuroscience, Yale University, New Haven, CT 06510, USA; Department of Neurosurgery, Yale University, New Haven, CT 06510, USA
| | - Anthony J Koleske
- Interdepartmental Neuroscience Program, Yale University, New Haven, CT 06510, USA; Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06510, USA; Department of Neuroscience, Yale University, New Haven, CT 06510, USA.
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23
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Farrukh A, Fan W, Zhao S, Salierno M, Paez JI, Del Campo A. Photoactivatable Adhesive Ligands for Light-Guided Neuronal Growth. Chembiochem 2018; 19:1271-1279. [PMID: 29633466 DOI: 10.1002/cbic.201800118] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Indexed: 12/21/2022]
Abstract
Neuro-regeneration after trauma requires growth and reconnection of neurons to reestablish information flow in particular directions across the damaged tissue. To support this process, biomaterials for nerve tissue regeneration need to provide spatial information to adhesion receptors on the cell membrane and to provide directionality to growing neurites. Here, photoactivatable adhesive peptides based on the CASIKVAVSADR laminin peptidomimetic are presented and applied to spatiotemporal control of neuronal growth to biomaterials in vitro. The introduction of a photoremovable group [6-nitroveratryl (NVOC), 3-(4,5-dimethoxy-2-nitrophenyl)butan-2-yl (DMNPB), or 2,2'-((3'-(1-hydroxypropan-2-yl)-4'-nitro-[1,1'-biphenyl]-4-yl)azanediyl)bis(ethan-1-ol) (HANBP)] at the amino terminal group of the K residue temporally inhibited the activity of the peptide. The bioactivity was regained through controlled light exposure. When used in neuronal culture substrates, the peptides allowed light-based control of the attachment and differentiation of neuronal cells. Site-selective irradiation activated adhesion and differentiation cues and guided seeded neurons to grow in predefined patterns. This is the first demonstration of ligand-based light-controlled interaction between neuronal cells and biomaterials.
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Affiliation(s)
- Aleeza Farrukh
- INM-Leibniz Institute for New Materials, Campus D2 2, 66123, Saarbrücken, Germany.,Max Planck Graduate Center, Forum Universitatis 2, Building 1111, 55122, Mainz, Germany
| | - Wenqiang Fan
- Institute of Physiological Chemistry, University Medical Center Johannes Gutenberg, Hanns-Dieter-Hüsch-Weg 19, 55128, Mainz, Germany
| | - Shifang Zhao
- INM-Leibniz Institute for New Materials, Campus D2 2, 66123, Saarbrücken, Germany.,Saarland University, Chemistry Department, 66123, Saarbrücken, Germany
| | - Marcelo Salierno
- Institute of Physiological Chemistry, University Medical Center Johannes Gutenberg, Hanns-Dieter-Hüsch-Weg 19, 55128, Mainz, Germany.,INIBIOMA, CRUB, Universidad Nacional del Comahue, Quintral 1250, 8400, S.C. Bariloche, Argentina
| | - Julieta I Paez
- INM-Leibniz Institute for New Materials, Campus D2 2, 66123, Saarbrücken, Germany
| | - Aránzazu Del Campo
- INM-Leibniz Institute for New Materials, Campus D2 2, 66123, Saarbrücken, Germany.,Saarland University, Chemistry Department, 66123, Saarbrücken, Germany
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24
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Ferrer-Ferrer M, Dityatev A. Shaping Synapses by the Neural Extracellular Matrix. Front Neuroanat 2018; 12:40. [PMID: 29867379 PMCID: PMC5962695 DOI: 10.3389/fnana.2018.00040] [Citation(s) in RCA: 102] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 04/25/2018] [Indexed: 11/13/2022] Open
Abstract
Accumulating data support the importance of interactions between pre- and postsynaptic neuronal elements with astroglial processes and extracellular matrix (ECM) for formation and plasticity of chemical synapses, and thus validate the concept of a tetrapartite synapse. Here we outline the major mechanisms driving: (i) synaptogenesis by secreted extracellular scaffolding molecules, like thrombospondins (TSPs), neuronal pentraxins (NPs) and cerebellins, which respectively promote presynaptic, postsynaptic differentiation or both; (ii) maturation of synapses via reelin and integrin ligands-mediated signaling; and (iii) regulation of synaptic plasticity by ECM-dependent control of induction and consolidation of new synaptic configurations. Particularly, we focused on potential importance of activity-dependent concerted activation of multiple extracellular proteases, such as ADAMTS4/5/15, MMP9 and neurotrypsin, for permissive and instructive events in synaptic remodeling through localized degradation of perisynaptic ECM and generation of proteolytic fragments as inducers of synaptic plasticity.
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Affiliation(s)
- Maura Ferrer-Ferrer
- Molecular Neuroplasticity German Center for Neurodegenerative Diseases (DZNE), Magdeburg, Germany
| | - Alexander Dityatev
- Molecular Neuroplasticity German Center for Neurodegenerative Diseases (DZNE), Magdeburg, Germany.,Center for Behavioral Brain Sciences (CBBS), Magdeburg, Germany.,Medical Faculty, Otto-von-Guericke University, Magdeburg, Germany
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25
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Abstract
The basement membrane is a thin but dense, sheet-like specialized type of extracellular matrix that has remarkably diverse functions tailored to individual tissues and organs. Tightly controlled spatial and temporal changes in its composition and structure contribute to the diversity of basement membrane functions. These different basement membranes undergo dynamic transformations throughout animal life, most notably during development. Numerous developmental mechanisms are regulated or mediated by basement membranes, often by a combination of molecular and mechanical processes. A particularly important process involves cell transmigration through a basement membrane because of its link to cell invasion in disease. While developmental and disease processes share some similarities, what clearly distinguishes the two is dysregulation of cells and extracellular matrices in disease. With its relevance to many developmental and disease processes, the basement membrane is a vitally important area of research that may provide novel insights into biological mechanisms and development of innovative therapeutic approaches. Here we present a review of developmental and disease dynamics of basement membranes in Caenorhabditis elegans, Drosophila, and vertebrates.
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26
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Hillen AEJ, Burbach JPH, Hol EM. Cell adhesion and matricellular support by astrocytes of the tripartite synapse. Prog Neurobiol 2018; 165-167:66-86. [PMID: 29444459 DOI: 10.1016/j.pneurobio.2018.02.002] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Revised: 07/25/2017] [Accepted: 02/07/2018] [Indexed: 12/18/2022]
Abstract
Astrocytes contribute to the formation, function, and plasticity of synapses. Their processes enwrap the neuronal components of the tripartite synapse, and due to this close interaction they are perfectly positioned to modulate neuronal communication. The interaction between astrocytes and synapses is facilitated by cell adhesion molecules and matricellular proteins, which have been implicated in the formation and functioning of tripartite synapses. The importance of such neuron-astrocyte integration at the synapse is underscored by the emerging role of astrocyte dysfunction in synaptic pathologies such as autism and schizophrenia. Here we review astrocyte-expressed cell adhesion molecules and matricellular molecules that play a role in integration of neurons and astrocytes within the tripartite synapse.
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Affiliation(s)
- Anne E J Hillen
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, 3584 CG Utrecht, The Netherlands; Department of Pediatrics/Child Neurology, VU University Medical Center, 1081 HV Amsterdam, The Netherlands
| | - J Peter H Burbach
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, 3584 CG Utrecht, The Netherlands
| | - Elly M Hol
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, 3584 CG Utrecht, The Netherlands; Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, 1098 XH Amsterdam, The Netherlands; Department of Neuroimmunology, Netherlands Institute for Neuroscience, An Institute of the Royal Netherlands Academy of Arts and Sciences, 1105 BA Amsterdam, The Netherlands.
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27
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Maselli RA, Arredondo J, Vázquez J, Chong JX, Bamshad MJ, Nickerson DA, Lara M, Ng F, Lo VL, Pytel P, McDonald CM. A presynaptic congenital myasthenic syndrome attributed to a homozygous sequence variant in LAMA5. Ann N Y Acad Sci 2018; 1413:119-125. [PMID: 29377152 DOI: 10.1111/nyas.13585] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 11/18/2017] [Accepted: 11/27/2017] [Indexed: 12/23/2022]
Abstract
We report a severe defect of neuromuscular transmission in a consanguineous patient with a homozygous variant in the laminin α5 subunit gene (LAMA5). The variant c.8046C > T (p.Arg2659Trp) is rare and has a predicted deleterious effect. The affected individual, who also carries a rare homozygous sequence variant in LAMA1, had normal cognitive function, but magnetic resonance brain imaging showed mild volume loss and periventricular T2 prolongation. Repetitive nerve stimulation at 2 Hz showed 50% decrement of compound muscle action potential amplitudes but 250% facilitation immediately after exercise, similar to that seen in Lambert-Eaton myasthenic syndrome. Endplate studies demonstrated a profound reduction of the endplate potential quantal content but normal amplitudes of miniature endplate potentials. Electron microscopy showed endplates with increased postsynaptic folding that were denuded or only partially occupied by small nerve terminals. Expression studies revealed that p.Arg2659Trp caused decreased binding of laminin α5 to SV2A and impaired laminin-521 cell adhesion and cell projection support in primary neuronal cultures. In summary, this report describing severe neuromuscular transmission failure in a patient with a LAMA5 mutation expands the list of phenotypes associated with defects in genes encoding α-laminins.
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Affiliation(s)
- Ricardo A Maselli
- Department of Neurology, University of California Davis, Sacramento, California
| | - Juan Arredondo
- Department of Neurology, University of California Davis, Sacramento, California
| | - Jessica Vázquez
- Department of Neurology, University of California Davis, Sacramento, California
| | - Jessica X Chong
- Department of Pediatrics, University of Washington, Seattle, Washington
| | - Michael J Bamshad
- Department of Pediatrics, University of Washington, Seattle, Washington.,Department of Genome Sciences, University of Washington, Seattle, Washington.,Division of Genetic Medicine, Seattle Children's Hospital, Seattle, Washington
| | - Deborah A Nickerson
- Department of Genome Sciences, University of Washington, Seattle, Washington
| | - Marian Lara
- Department of Neurology, University of California Davis, Sacramento, California
| | - Fiona Ng
- Department of Neurology, University of California Davis, Sacramento, California
| | - Victoria Lee Lo
- Department of Neurology, University of California Davis, Sacramento, California
| | - Peter Pytel
- Department of Pathology, University of Chicago, Chicago, Illinois
| | - Craig M McDonald
- Department of Medicine and Rehabilitation, University of California Davis, Sacramento, California
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28
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Lee KM, Chand KK, Hammond LA, Lavidis NA, Noakes PG. Functional decline at the aging neuromuscular junction is associated with altered laminin-α4 expression. Aging (Albany NY) 2017; 9:880-899. [PMID: 28301326 PMCID: PMC5391237 DOI: 10.18632/aging.101198] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 03/03/2017] [Indexed: 12/04/2022]
Abstract
Laminin-α4 is involved in the alignment of active zones to postjunctional folds at the neuromuscular junction (NMJ). Prior study has implicated laminin-α4 in NMJ maintenance, with altered NMJ morphology observed in adult laminin-α4 deficient mice (lama4−/−). The present study further investigated the role of laminin-α4 in NMJ maintenance by functional characterization of transmission properties, morphological investigation of synaptic proteins including synaptic laminin-α4, and neuromotor behavioral testing. Results showed maintained perturbed transmission properties at lama4−/− NMJs from adult (3 months) through to aged (18-22 months). Hind-limb grip force demonstrated similar trends as transmission properties, with maintained weaker grip force across age groups in lama4−/−. Interestingly, both transmission properties and hind-limb grip force in aged wild-types resembled those observed in adult lama4−/−. Most significantly, altered expression of laminin-α4 was noted at the wild-type NMJs prior to the observed decline in transmission properties, suggesting that altered laminin-α4 expression precedes the decline of neurotransmission in aging wild-types. These findings significantly support the role of laminin-α4 in maintenance of the NMJ during aging.
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Affiliation(s)
- Kah Meng Lee
- School of Biomedical Sciences, The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Kirat K Chand
- School of Biomedical Sciences, The University of Queensland, St. Lucia, Queensland 4072, Australia.,University of Queensland Centre for Clinical Research, The University of Queensland, Herston, Queensland 4029, Australia
| | - Luke A Hammond
- Queensland Brain Institute, The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Nickolas A Lavidis
- School of Biomedical Sciences, The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Peter G Noakes
- School of Biomedical Sciences, The University of Queensland, St. Lucia, Queensland 4072, Australia.,Queensland Brain Institute, The University of Queensland, St. Lucia, Queensland 4072, Australia
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29
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Super-Resolution Microscopy Reveals a Nanoscale Organization of Acetylcholine Receptors for Trans-Synaptic Alignment at Neuromuscular Synapses. eNeuro 2017; 4:eN-NWR-0232-17. [PMID: 28798955 PMCID: PMC5550840 DOI: 10.1523/eneuro.0232-17.2017] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Revised: 07/24/2017] [Accepted: 07/25/2017] [Indexed: 11/30/2022] Open
Abstract
The neuromuscular junction (NMJ) is a chemical synapse formed between motoneurons and skeletal muscle fibers. The vertebrate NMJ uses acetylcholine (ACh) as the neurotransmitter and features numerous invaginations of the postsynaptic muscle membrane termed junctional folds. ACh receptors (AChRs) are believed to be concentrated on the crest of junctional folds but their spatial organization remains to be fully understood. In this study, we utilized super-resolution microscopy to examine the nanoscale organization of AChRs at NMJ. Using Structured Illumination Microscopy, we found that AChRs appear as stripes within the pretzel-shaped mouse NMJs, which however, do not correlate with the size of the crests of junctional folds. By comparing the localization of AChRs with several pre- and postsynaptic markers of distinct compartments of NMJs, we found that AChRs are not distributed evenly across the crest of junctional folds as previously thought. Instead, AChR stripes are more closely aligned with the openings of junctional folds as well as with the presynaptic active zone. Using Stochastic Optical Reconstruction Microscopy (STORM) for increased resolution, we found that each AChR stripe contains an AChR-poor slit at the center that is equivalent to the size of the opening of junctional folds. Together, these findings indicate that AChRs are largely localized to the edges of crests surrounding the opening of folds to align with the presynaptic active zones. Such a nanoscale organization of AChRs potentially enables trans-synaptic alignment for effective synaptic transmission of NMJs.
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30
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Maselli RA, Arredondo J, Vázquez J, Chong JX, Bamshad MJ, Nickerson DA, Lara M, Ng F, Lo VL, Pytel P, McDonald CM. Presynaptic congenital myasthenic syndrome with a homozygous sequence variant in LAMA5 combines myopia, facial tics, and failure of neuromuscular transmission. Am J Med Genet A 2017; 173:2240-2245. [PMID: 28544784 DOI: 10.1002/ajmg.a.38291] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 04/03/2017] [Accepted: 04/24/2017] [Indexed: 12/13/2022]
Abstract
Defects in genes encoding the isoforms of the laminin alpha subunit have been linked to various phenotypic manifestations, including brain malformations, muscular dystrophy, ocular defects, cardiomyopathy, and skin abnormalities. We report here a severe defect of neuromuscular transmission in a consanguineous patient with a homozygous variant in the laminin alpha-5 subunit gene (LAMA5). The variant c.8046C>T (p.Arg2659Trp) is rare and has a predicted deleterious effect. The affected individual, who also carries a rare homozygous sequence variant in LAMA1, had muscle weakness, myopia, and facial tics. Magnetic resonance imaging of brain showed mild volume loss and periventricular T2 prolongation. Repetitive nerve stimulation revealed 50% decrement of compound muscle action potential amplitudes and 250% facilitation immediately after exercise, Endplate studies identified a profound reduction of the endplate potential quantal content and endplates with normal postsynaptic folding that were denuded or partially occupied by small nerve terminals. Expression studies revealed that p.Arg2659Trp caused decreased binding of laminin alpha-5 to SV2A and impaired laminin-521 cell-adhesion and cell projection support in primary neuronal cultures. In summary, this report describing severe neuromuscular transmission failure in a patient with a LAMA5 mutation expands the list of phenotypes associated with defects in genes encoding alpha-laminins.
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Affiliation(s)
- Ricardo A Maselli
- Department of Neurology, University of California Davis, Sacramento, California
| | - Juan Arredondo
- Department of Neurology, University of California Davis, Sacramento, California
| | - Jessica Vázquez
- Department of Neurology, University of California Davis, Sacramento, California
| | - Jessica X Chong
- Department of Pediatrics, University of Washington, Seattle, Washington
| | | | - Michael J Bamshad
- Department of Pediatrics, University of Washington, Seattle, Washington.,Department of Genome Sciences, University of Washington, Seattle, Washington.,Division of Genetic Medicine, Seattle Children's Hospital, Seattle, Washington
| | - Deborah A Nickerson
- Department of Genome Sciences, University of Washington, Seattle, Washington
| | - Marian Lara
- Department of Neurology, University of California Davis, Sacramento, California
| | - Fiona Ng
- Department of Neurology, University of California Davis, Sacramento, California
| | - Victoria L Lo
- Department of Neurology, University of California Davis, Sacramento, California
| | - Peter Pytel
- Department of Pathology, University of Chicago, Chicago, Illinois
| | - Craig M McDonald
- Department of Medicine and Rehabilitation, University of California Davis, Sacramento, California
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32
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Ross JA, Webster RG, Lechertier T, Reynolds LE, Turmaine M, Bencze M, Jamshidi Y, Cetin H, Muntoni F, Beeson D, Hodilvala-Dilke K, Conti FJ. Multiple roles of integrin-α3 at the neuromuscular junction. J Cell Sci 2017; 130:1772-1784. [PMID: 28386022 PMCID: PMC5450193 DOI: 10.1242/jcs.201103] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Accepted: 03/31/2017] [Indexed: 12/22/2022] Open
Abstract
The neuromuscular junction (NMJ) is the synapse between motoneurons and skeletal muscle, and is responsible for eliciting muscle contraction. Neurotransmission at synapses depends on the release of synaptic vesicles at sites called active zones (AZs). Various proteins of the extracellular matrix are crucial for NMJ development; however, little is known about the identity and functions of the receptors that mediate their effects. Using genetically modified mice, we find that integrin-α3 (encoded by Itga3), an adhesion receptor at the presynaptic membrane, is involved in the localisation of AZ components and efficient synaptic vesicle release. Integrin-α3 also regulates integrity of the synapse - mutant NMJs present with progressive structural changes and upregulated autophagy, features commonly observed during ageing and in models of neurodegeneration. Unexpectedly, we find instances of nerve terminal detachment from the muscle fibre; to our knowledge, this is the first report of a receptor that is required for the physical anchorage of pre- and postsynaptic elements at the NMJ. These results demonstrate multiple roles of integrin-α3 at the NMJ, and suggest that alterations in its function could underlie defects that occur in neurodegeneration or ageing.
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Affiliation(s)
- Jacob A Ross
- Dubowitz Neuromuscular Centre, Institute of Child Health, University College London, 30 Guilford Street, London WC1N 1EH, UK
| | - Richard G Webster
- Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DS, UK
| | - Tanguy Lechertier
- Centre for Tumour Biology, Barts Cancer Institute, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK
| | - Louise E Reynolds
- Centre for Tumour Biology, Barts Cancer Institute, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK
| | - Mark Turmaine
- Department of Cell and Developmental Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Maximilien Bencze
- Dubowitz Neuromuscular Centre, Institute of Child Health, University College London, 30 Guilford Street, London WC1N 1EH, UK
| | - Yalda Jamshidi
- Department of Genetics, Institute of Molecular and Clinical Sciences, St George's University of London, Cranmer Terrace, London SW17 0RE, UK
| | - Hakan Cetin
- Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DS, UK
| | - Francesco Muntoni
- Dubowitz Neuromuscular Centre, Institute of Child Health, University College London, 30 Guilford Street, London WC1N 1EH, UK
| | - David Beeson
- Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DS, UK
| | - Kairbaan Hodilvala-Dilke
- Centre for Tumour Biology, Barts Cancer Institute, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK
| | - Francesco J Conti
- Dubowitz Neuromuscular Centre, Institute of Child Health, University College London, 30 Guilford Street, London WC1N 1EH, UK
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33
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Yao Y. Laminin: loss-of-function studies. Cell Mol Life Sci 2017; 74:1095-1115. [PMID: 27696112 PMCID: PMC11107706 DOI: 10.1007/s00018-016-2381-0] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Revised: 09/25/2016] [Accepted: 09/26/2016] [Indexed: 01/13/2023]
Abstract
Laminin, one of the most widely expressed extracellular matrix proteins, exerts many important functions in multiple organs/systems and at various developmental stages. Although its critical roles in embryonic development have been demonstrated, laminin's functions at later stages remain largely unknown, mainly due to its intrinsic complexity and lack of research tools (most laminin mutants are embryonic lethal). With the advance of genetic and molecular techniques, many new laminin mutants have been generated recently. These new mutants usually have a longer lifespan and show previously unidentified phenotypes. Not only do these studies suggest novel functions of laminin, but also they provide invaluable animal models that allow investigation of laminin's functions at late stages. Here, I first briefly introduce the nomenclature, structure, and biochemistry of laminin in general. Next, all the loss-of-function mutants/models for each laminin chain are discussed and their phenotypes compared. I hope to provide a comprehensive review on laminin functions and its loss-of-function models, which could serve as a reference for future research in this understudied field.
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Affiliation(s)
- Yao Yao
- College of Pharmacy, University of Minnesota, Duluth, MN, 55812, USA.
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34
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Chand KK, Lee KM, Lavidis NA, Noakes PG. Loss of laminin‐a4 results in pre‐ and postsynaptic modifications at the neuromuscular junction. FASEB J 2016; 31:1323-1336. [DOI: 10.1096/fj.201600899r] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Accepted: 12/06/2016] [Indexed: 11/11/2022]
Affiliation(s)
- Kirat K. Chand
- School of Biomedical Sciences St. Lucia Queensland Australia
| | - Kah Meng Lee
- School of Biomedical Sciences St. Lucia Queensland Australia
| | | | - Peter G. Noakes
- School of Biomedical Sciences St. Lucia Queensland Australia
- Queensland Brain InstituteThe University of Queensland St. Lucia Queensland Australia
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35
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Rogers RS, Nishimune H. The role of laminins in the organization and function of neuromuscular junctions. Matrix Biol 2016; 57-58:86-105. [PMID: 27614294 DOI: 10.1016/j.matbio.2016.08.008] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 08/10/2016] [Accepted: 08/17/2016] [Indexed: 01/11/2023]
Abstract
The synapse between motor neurons and skeletal muscle is known as the neuromuscular junction (NMJ). Proper alignment of presynaptic and post-synaptic structures of motor neurons and muscle fibers, respectively, is essential for efficient motor control of skeletal muscles. The synaptic cleft between these two cells is filled with basal lamina. Laminins are heterotrimer extracellular matrix molecules that are key members of the basal lamina. Laminin α4, α5, and β2 chains specifically localize to NMJs, and these laminin isoforms play a critical role in maintenance of NMJs and organization of synaptic vesicle release sites known as active zones. These individual laminin chains exert their role in organizing NMJs by binding to their receptors including integrins, dystroglycan, and voltage-gated calcium channels (VGCCs). Disruption of these laminins or the laminin-receptor interaction occurs in neuromuscular diseases including Pierson syndrome and Lambert-Eaton myasthenic syndrome (LEMS). Interventions to maintain proper level of laminins and their receptor interactions may be insightful in treating neuromuscular diseases and aging related degeneration of NMJs.
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Affiliation(s)
- Robert S Rogers
- Department of Anatomy and Cell Biology, University of Kansas School of Medicine, Kansas City, Kansas, USA.
| | - Hiroshi Nishimune
- Department of Anatomy and Cell Biology, University of Kansas School of Medicine, Kansas City, Kansas, USA.
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36
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Autoimmunity against laminins. Clin Immunol 2016; 170:39-52. [PMID: 27464450 DOI: 10.1016/j.clim.2016.07.021] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 04/30/2016] [Accepted: 07/22/2016] [Indexed: 12/12/2022]
Abstract
Laminins are ubiquitous constituents of the basement membranes with major architectural and functional role as supported by the fact that absence or mutations of laminins lead to either lethal or severely impairing phenotypes. Besides genetic defects, laminins are involved in a wide range of human diseases including cancer, infections, and inflammatory diseases, as well as autoimmune disorders. A growing body of evidence implicates several laminin chains as autoantigens in blistering skin diseases, collagenoses, vasculitis, or post-infectious autoimmunity. The current paper reviews the existing knowledge on autoimmunity against laminins referring to both experimental and clinical data, and on therapeutic implications of anti-laminin antibodies. Further investigation of relevant laminin epitopes in pathogenic autoimmunity would facilitate the development of appropriate diagnostic tools for thorough characterization of patients' antibody specificities and should decisively contribute to designing more specific therapeutic interventions.
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37
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Dual-color STED microscopy reveals a sandwich structure of Bassoon and Piccolo in active zones of adult and aged mice. Sci Rep 2016; 6:27935. [PMID: 27321892 PMCID: PMC4913281 DOI: 10.1038/srep27935] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 05/16/2016] [Indexed: 11/08/2022] Open
Abstract
Presynaptic active zones play a pivotal role as synaptic vesicle release sites for synaptic transmission, but the molecular architecture of active zones in mammalian neuromuscular junctions (NMJs) at sub-diffraction limited resolution remains unknown. Bassoon and Piccolo are active zone specific cytosolic proteins essential for active zone assembly in NMJs, ribbon synapses, and brain synapses. These proteins are thought to colocalize and share some functions at active zones. Here, we report an unexpected finding of non-overlapping localization of these two proteins in mouse NMJs revealed using dual-color stimulated emission depletion (STED) super resolution microscopy. Piccolo puncta sandwiched Bassoon puncta and aligned in a Piccolo-Bassoon-Piccolo structure in adult NMJs. P/Q-type voltage-gated calcium channel (VGCC) puncta colocalized with Bassoon puncta. The P/Q-type VGCC and Bassoon protein levels decreased significantly in NMJs from aged mouse. In contrast, the Piccolo levels in NMJs from aged mice were comparable to levels in adult mice. This study revealed the molecular architecture of active zones in mouse NMJs at sub-diffraction limited resolution, and described the selective degeneration mechanism of active zone proteins in NMJs from aged mice. Interestingly, the localization pattern of active zone proteins described herein is similar to active zone structures described using electron microscope tomography.
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38
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Neuron-Glia Interactions in Neural Plasticity: Contributions of Neural Extracellular Matrix and Perineuronal Nets. Neural Plast 2016; 2016:5214961. [PMID: 26881114 PMCID: PMC4736403 DOI: 10.1155/2016/5214961] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Accepted: 08/10/2015] [Indexed: 11/17/2022] Open
Abstract
Synapses are specialized structures that mediate rapid and efficient signal transmission between neurons and are surrounded by glial cells. Astrocytes develop an intimate association with synapses in the central nervous system (CNS) and contribute to the regulation of ion and neurotransmitter concentrations. Together with neurons, they shape intercellular space to provide a stable milieu for neuronal activity. Extracellular matrix (ECM) components are synthesized by both neurons and astrocytes and play an important role in the formation, maintenance, and function of synapses in the CNS. The components of the ECM have been detected near glial processes, which abut onto the CNS synaptic unit, where they are part of the specialized macromolecular assemblies, termed perineuronal nets (PNNs). PNNs have originally been discovered by Golgi and represent a molecular scaffold deposited in the interface between the astrocyte and subsets of neurons in the vicinity of the synapse. Recent reports strongly suggest that PNNs are tightly involved in the regulation of synaptic plasticity. Moreover, several studies have implicated PNNs and the neural ECM in neuropsychiatric diseases. Here, we highlight current concepts relating to neural ECM and PNNs and describe an in vitro approach that allows for the investigation of ECM functions for synaptogenesis.
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39
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Abstract
Neuromuscular diseases can affect the survival of peripheral neurons, their axons extending to peripheral targets, their synaptic connections onto those targets, or the targets themselves. Examples include motor neuron diseases such as Amyotrophic Lateral Sclerosis, peripheral neuropathies such as Charcot-Marie-Tooth diseases, myasthenias, and muscular dystrophies. Characterizing these phenotypes in mouse models requires an integrated approach, examining both the nerve and muscle histologically, anatomically, and functionally by electrophysiology. Defects observed at these levels can be related back to onset, severity, and progression, as assessed by "Quality of life measures" including tests of gross motor performance such as gait or grip strength. This chapter describes methods for assessing neuromuscular disease models in mice, and how interpretation of these tests can be complicated by the inter-relatedness of the phenotypes.
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Affiliation(s)
- Robert W Burgess
- The Jackson Laboratory, 600 Main Street, Bar Harbor, ME, 04609, USA.
| | - Gregory A Cox
- The Jackson Laboratory, 600 Main Street, Bar Harbor, ME, 04609, USA
| | - Kevin L Seburn
- The Jackson Laboratory, 600 Main Street, Bar Harbor, ME, 04609, USA
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40
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Abstract
The neuromuscular junction (NMJ) is a synapse between motor neurons and skeletal muscle fibers, and is critical for control of muscle contraction. Its formation requires neuronal agrin that acts by binding to LRP4 to stimulate MuSK. Mutations have been identified in agrin, MuSK, and LRP4 in patients with congenital myasthenic syndrome, and patients with myasthenia gravis develop antibodies against agrin, LRP4, and MuSK. However, it remains unclear whether the agrin signaling pathway is critical for NMJ maintenance because null mutation of any of the three genes is perinatal lethal. In this study, we generated imKO mice, a mutant strain whose LRP4 gene can be deleted in muscles by doxycycline (Dox) treatment. Ablation of the LRP4 gene in adult muscle enabled studies of its role in NMJ maintenance. We demonstrate that Dox treatment of P30 mice reduced muscle strength and compound muscle action potentials. AChR clusters became fragmented with diminished junctional folds and synaptic vesicles. The amplitude and frequency of miniature endplate potentials were reduced, indicating impaired neuromuscular transmission and providing cellular mechanisms of adult LRP4 deficiency. We showed that LRP4 ablation led to the loss of synaptic agrin and the 90 kDa fragments, which occurred ahead of other prejunctional and postjunctional components, suggesting that LRP4 may regulate the stability of synaptic agrin. These observations demonstrate that LRP4 is essential for maintaining the structural and functional integrity of the NMJ and that loss of muscle LRP4 in adulthood alone is sufficient to cause myasthenic symptoms.
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41
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Chand KK, Lee KM, Schenning MP, Lavidis NA, Noakes PG. Loss of β2-laminin alters calcium sensitivity and voltage-gated calcium channel maturation of neurotransmission at the neuromuscular junction. J Physiol 2014; 593:245-65. [PMID: 25556799 DOI: 10.1113/jphysiol.2014.284133] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 10/23/2014] [Indexed: 12/16/2022] Open
Abstract
KEY POINTS Neuromuscular junctions from β2-laminin-deficient mice exhibit lower levels of calcium sensitivity. Loss of β2-laminin leads to a failure in switching from N- to P/Q-type voltage-gated calcium channel (VGCC)-mediated transmitter release that normally occurs with neuromuscular junction maturation. The motor nerve terminals from β2-laminin-deficient mice fail to up-regulate the expression of P/Q-type VGCCs clusters and down-regulate N-type VGCCs clusters, as they mature. There is decreased co-localisation of presynaptic specialisations in β2-laminin-deficient neuromuscular junctions as a consequence of lesser P/Q-type VGCC expression. These findings support the idea that β2-laminin is critical in the organisation and maintenance of active zones at the neuromuscular junction via its interaction with P/Q-type VGCCs, which aid in stabilisation of the synapse. β2-laminin is a key mediator in the differentiation and formation of the skeletal neuromuscular junction. Loss of β2-laminin results in significant structural and functional aberrations such as decreased number of active zones and reduced spontaneous release of transmitter. In vitro β2-laminin has been shown to bind directly to the pore forming subunit of P/Q-type voltage-gated calcium channels (VGCCs). Neurotransmission is initially mediated by N-type VGCCs, but by postnatal day 18 switches to P/Q-type VGCC dominance. The present study investigated the changes in neurotransmission during the switch from N- to P/Q-type VGCC-mediated transmitter release at β2-laminin-deficient junctions. Analysis of the relationship between quantal content and extracellular calcium concentrations demonstrated a decrease in the calcium sensitivity, but no change in calcium dependence at β2-laminin-deficient junctions. Electrophysiological studies on VGCC sub-types involved in transmitter release indicate N-type VGCCs remain the primary mediator of transmitter release at matured β2-laminin-deficient junctions. Immunohistochemical analyses displayed irregularly shaped and immature β2-laminin-deficient neuromuscular junctions when compared to matured wild-type junctions. β2-laminin-deficient junctions also maintained the presence of N-type VGCC clustering within the presynaptic membrane, which supported the functional findings of the present study. We conclude that β2-laminin is a key regulator in development of the NMJ, with its loss resulting in reduced transmitter release due to decreased calcium sensitivity stemming from a failure to switch from N- to P/Q-type VGCC-mediated synaptic transmission.
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Affiliation(s)
- Kirat K Chand
- School of Biomedical Sciences, The University of Queensland, St Lucia, 4067, Australia
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Levy AD, Omar MH, Koleske AJ. Extracellular matrix control of dendritic spine and synapse structure and plasticity in adulthood. Front Neuroanat 2014; 8:116. [PMID: 25368556 PMCID: PMC4202714 DOI: 10.3389/fnana.2014.00116] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Accepted: 09/29/2014] [Indexed: 12/20/2022] Open
Abstract
Dendritic spines are the receptive contacts at most excitatory synapses in the central nervous system. Spines are dynamic in the developing brain, changing shape as they mature as well as appearing and disappearing as they make and break connections. Spines become much more stable in adulthood, and spine structure must be actively maintained to support established circuit function. At the same time, adult spines must retain some plasticity so their structure can be modified by activity and experience. As such, the regulation of spine stability and remodeling in the adult animal is critical for normal function, and disruption of these processes is associated with a variety of late onset diseases including schizophrenia and Alzheimer's disease. The extracellular matrix (ECM), composed of a meshwork of proteins and proteoglycans, is a critical regulator of spine and synapse stability and plasticity. While the role of ECM receptors in spine regulation has been extensively studied, considerably less research has focused directly on the role of specific ECM ligands. Here, we review the evidence for a role of several brain ECM ligands and remodeling proteases in the regulation of dendritic spine and synapse formation, plasticity, and stability in adults.
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Affiliation(s)
- Aaron D Levy
- Interdepartmental Neuroscience Program, Yale University New Haven, CT, USA ; Department of Molecular Biophysics and Biochemistry, Yale University New Haven, CT, USA
| | - Mitchell H Omar
- Interdepartmental Neuroscience Program, Yale University New Haven, CT, USA ; Department of Molecular Biophysics and Biochemistry, Yale University New Haven, CT, USA
| | - Anthony J Koleske
- Interdepartmental Neuroscience Program, Yale University New Haven, CT, USA ; Department of Molecular Biophysics and Biochemistry, Yale University New Haven, CT, USA ; Department of Neurobiology, Yale University New Haven, CT, USA
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Darabid H, Perez-Gonzalez AP, Robitaille R. Neuromuscular synaptogenesis: coordinating partners with multiple functions. Nat Rev Neurosci 2014; 15:630-1. [DOI: 10.1038/nrn3821] [Citation(s) in RCA: 111] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Perlecan antagonizes collagen IV and ADAMTS9/GON-1 in restricting the growth of presynaptic boutons. J Neurosci 2014; 34:10311-24. [PMID: 25080592 DOI: 10.1523/jneurosci.5128-13.2014] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
In the mature nervous system, a significant fraction of synapses are structurally stable over a long time scale. However, the mechanisms that restrict synaptic growth within a confined region are poorly understood. Here, we identified that in the C. elegans neuromuscular junction, collagens Type IV and XVIII, and the secreted metalloprotease ADAMTS/GON-1 are critical for growth restriction of presynaptic boutons. Without these components, ectopic boutons progressively invade into the nonsynaptic region. Perlecan/UNC-52 promotes the growth of ectopic boutons and functions antagonistically to collagen Type IV and GON-1 but not to collagen XVIII. The growth constraint of presynaptic boutons correlates with the integrity of the extracellular matrix basal lamina or basement membrane (BM), which surrounds chemical synapses. Fragmented BM appears in the region where ectopic boutons emerge. Further removal of UNC-52 improves the BM integrity and the tight association between BM and presynaptic boutons. Together, our results unravel the complex role of the BM in restricting the growth of presynaptic boutons and reveal the antagonistic function of perlecan on Type IV collagen and ADAMTS protein.
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Kostourou V, Papalazarou V. Non-collagenous ECM proteins in blood vessel morphogenesis and cancer. Biochim Biophys Acta Gen Subj 2014; 1840:2403-13. [PMID: 24576673 DOI: 10.1016/j.bbagen.2014.02.018] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Revised: 02/14/2014] [Accepted: 02/17/2014] [Indexed: 12/12/2022]
Abstract
BACKGROUND The extracellular matrix (ECM) is constituted by diverse composite structures, which determine the specific to each organ, histological architecture and provides cells with biological information, mechanical support and a scaffold for adhesion and migration. The pleiotropic effects of the ECM stem from the dynamic changes in its molecular composition and the ability to remodel in order to effectively regulate biological outcomes. Besides collagens, fibronectin and laminin are two major fiber-forming constituents of various ECM structures. SCOPE OF REVIEW This review will focus on the properties and the biological functions of non-collagenous extracellular matrix especially on laminin and fibronectin that are currently emerging as important regulators of blood vessel formation and function in health and disease. MAJOR CONCLUSIONS The ECM is a fundamental component of the microenvironment of blood vessels, with activities extending beyond providing a vascular scaffold; extremely versatile it directly or indirectly modulates all essential cellular functions crucial for angiogenesis, including cell adhesion, migration, proliferation, differentiation and lumen formation. Specifically, fibronectin and laminins play decisive roles in blood vessel morphogenesis both during embryonic development and in pathological conditions, such as cancer. GENERAL SIGNIFICANCE Emerging evidence demonstrates the importance of ECM function during embryonic development, organ formation and tissue homeostasis. A wealth of data also illustrates the crucial role of the ECM in several human pathophysiological processes, including fibrosis, skeletal diseases, vascular pathologies and cancer. Notably, several ECM components have been identified as potential therapeutic targets for various diseases, including cancer. This article is part of a Special Issue entitled Matrix-mediated cell behaviour and properties.
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Affiliation(s)
- Vassiliki Kostourou
- Vascular Adhesion Lab, BSRC Alexander Fleming, 34 Fleming Str., Vari, 166 72 Athens, Greece
| | - Vassilis Papalazarou
- Vascular Adhesion Lab, BSRC Alexander Fleming, 34 Fleming Str., Vari, 166 72 Athens, Greece
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Robinson KG, Mendonca JL, Militar JL, Theroux MC, Dabney KW, Shah SA, Miller F, Akins RE. Disruption of basal lamina components in neuromotor synapses of children with spastic quadriplegic cerebral palsy. PLoS One 2013; 8:e70288. [PMID: 23976945 PMCID: PMC3745387 DOI: 10.1371/journal.pone.0070288] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2012] [Accepted: 06/18/2013] [Indexed: 11/18/2022] Open
Abstract
Cerebral palsy (CP) is a static encephalopathy occurring when a lesion to the developing brain results in disordered movement and posture. Patients present with sometimes overlapping spastic, athetoid/dyskinetic, and ataxic symptoms. Spastic CP, which is characterized by stiff muscles, weakness, and poor motor control, accounts for ∼80% of cases. The detailed mechanisms leading to disordered movement in spastic CP are not completely understood, but clinical experience and recent studies suggest involvement of peripheral motor synapses. For example, it is recognized that CP patients have altered sensitivities to drugs that target neuromuscular junctions (NMJs), and protein localization studies suggest that NMJ microanatomy is disrupted in CP. Since CP originates during maturation, we hypothesized that NMJ disruption in spastic CP is associated with retention of an immature neuromotor phenotype later in life. Scoliosis patients with spastic CP or idiopathic disease were enrolled in a prospective, partially-blinded study to evaluate NMJ organization and neuromotor maturation. The localization of synaptic acetylcholine esterase (AChE) relative to postsynaptic acetylcholine receptor (AChR), synaptic laminin β2, and presynaptic vesicle protein 2 (SV2) appeared mismatched in the CP samples; whereas, no significant disruption was found between AChR and SV2. These data suggest that pre- and postsynaptic NMJ components in CP children were appropriately distributed even though AChE and laminin β2 within the synaptic basal lamina appeared disrupted. Follow up electron microscopy indicated that NMJs from CP patients appeared generally mature and similar to controls with some differences present, including deeper postsynaptic folds and reduced presynaptic mitochondria. Analysis of maturational markers, including myosin, syntrophin, myogenin, and AChR subunit expression, and telomere lengths, all indicated similar levels of motor maturation in the two groups. Thus, NMJ disruption in CP was found to principally involve components of the synaptic basal lamina and subtle ultra-structural modifications but appeared unrelated to neuromotor maturational status.
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Affiliation(s)
- Karyn G. Robinson
- Nemours Biomedical Research, Alfred I. duPont Hospital for Children, Wilmington, Delaware, United States of America
| | - Janet L. Mendonca
- Nemours Biomedical Research, Alfred I. duPont Hospital for Children, Wilmington, Delaware, United States of America
| | - Jaimee L. Militar
- Nemours Biomedical Research, Alfred I. duPont Hospital for Children, Wilmington, Delaware, United States of America
| | - Mary C. Theroux
- Department of Anesthesiology and Critical Care, Alfred I. duPont Hospital for Children, Wilmington, Delaware, United States of America
| | - Kirk W. Dabney
- Department of Orthopedic Surgery, Alfred I. duPont Hospital for Children, Wilmington, Delaware, United States of America
| | - Suken A. Shah
- Department of Orthopedic Surgery, Alfred I. duPont Hospital for Children, Wilmington, Delaware, United States of America
| | - Freeman Miller
- Department of Orthopedic Surgery, Alfred I. duPont Hospital for Children, Wilmington, Delaware, United States of America
| | - Robert E. Akins
- Nemours Biomedical Research, Alfred I. duPont Hospital for Children, Wilmington, Delaware, United States of America
- * E-mail:
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Nishimune H. Active zones of mammalian neuromuscular junctions: formation, density, and aging. Ann N Y Acad Sci 2013; 1274:24-32. [PMID: 23252894 DOI: 10.1111/j.1749-6632.2012.06836.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Presynaptic active zones are synaptic vesicle release sites that play essential roles in the function and pathology of mammalian neuromuscular junctions (NMJs). The molecular mechanisms of active zone organization use presynaptic voltage-dependent calcium channels (VDCCs) in NMJs as scaffolding proteins. VDCCs interact extracellularly with the muscle-derived synapse organizer, laminin β2 and interact intracellularly with active zone-specific proteins, such as Bassoon, CAST/Erc2/ELKS2alpha, ELKS, Piccolo, and RIMs. These molecular mechanisms are supported by studies in P/Q- and N-type VDCCs double-knockout mice, and they are consistent with the pathological conditions of Lambert-Eaton myasthenic syndrome and Pierson syndrome, which are caused by autoantibodies against VDCCs or by a laminin β2 mutation. During normal postnatal maturation, NMJs maintain the density of active zones, while NMJs triple their size. However, active zones become impaired during aging. Propitiously, muscle exercise ameliorates the active zone impairment in aged NMJs, which suggests the potential for therapeutic strategies.
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Affiliation(s)
- Hiroshi Nishimune
- Department of Anatomy and Cell Biology, University of Kansas Medical School, Kansas City, 66160, USA.
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Maselli RA, Arredondo J, Ferns MJ, Wollmann RL. Synaptic basal lamina-associated congenital myasthenic syndromes. Ann N Y Acad Sci 2013; 1275:36-48. [PMID: 23278576 DOI: 10.1111/j.1749-6632.2012.06807.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Proteins associated with the basal lamina (BL) participate in complex signal transduction processes that are essential for the development and maintenance of the neuromuscular junction (NMJ). Most important junctional BL proteins are collagens, such as collagen IV (α3-6), collagen XIII, and ColQ; laminins; nidogens; and heparan sulfate proteoglycans, such as perlecan and agrin. Mice lacking Colq (Colq(-/-)), laminin β2 (Lamb2(-/-)), or collagen XIII (Col13a1(-/-)) show immature nerve terminals enwrapped by Schwann cell projections that invaginate into the synaptic cleft and decrease contact surface for neurotransmission. Human mutations in COLQ, LAMB2, and AGRN cause congenital myasthenic syndromes (CMSs) owing to deficiency of ColQ, laminin-β2, and agrin, respectively. In these syndromes the NMJ ultrastructure shows striking resemblance to that of mice lacking the corresponding protein; furthermore, the extracellular localization of mutant proteins may provide favorable conditions for replacement strategies based on gene therapy and stem cells.
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Affiliation(s)
- Ricardo A Maselli
- Department of Neurology, University of California, Davis, California, USA.
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Affiliation(s)
- Anna Domogatskaya
- Division of Matrix Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institute, 171 77 Stockholm, Sweden; , ,
| | - Sergey Rodin
- Division of Matrix Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institute, 171 77 Stockholm, Sweden; , ,
| | - Karl Tryggvason
- Division of Matrix Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institute, 171 77 Stockholm, Sweden; , ,
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Activity-dependent retrograde laminin A signaling regulates synapse growth at Drosophila neuromuscular junctions. Proc Natl Acad Sci U S A 2012; 109:17699-704. [PMID: 23054837 DOI: 10.1073/pnas.1206416109] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Retrograde signals induced by synaptic activities are derived from postsynaptic cells to potentiate presynaptic properties, such as cytoskeletal dynamics, gene expression, and synaptic growth. However, it is not known whether activity-dependent retrograde signals can also depotentiate synaptic properties. Here we report that laminin A (LanA) functions as a retrograde signal to suppress synapse growth at Drosophila neuromuscular junctions (NMJs). The presynaptic integrin pathway consists of the integrin subunit βν and focal adhesion kinase 56 (Fak56), both of which are required to suppress crawling activity-dependent NMJ growth. LanA protein is localized in the synaptic cleft and only muscle-derived LanA is functional in modulating NMJ growth. The LanA level at NMJs is inversely correlated with NMJ size and regulated by larval crawling activity, synapse excitability, postsynaptic response, and anterograde Wnt/Wingless signaling, all of which modulate NMJ growth through LanA and βν. Our data indicate that synaptic activities down-regulate levels of the retrograde signal LanA to promote NMJ growth.
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