1
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Stassart RM, Gomez-Sanchez JA, Lloyd AC. Schwann Cells as Orchestrators of Nerve Repair: Implications for Tissue Regeneration and Pathologies. Cold Spring Harb Perspect Biol 2024; 16:a041363. [PMID: 38199866 PMCID: PMC11146315 DOI: 10.1101/cshperspect.a041363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2024]
Abstract
Peripheral nerves exist in a stable state in adulthood providing a rapid bidirectional signaling system to control tissue structure and function. However, following injury, peripheral nerves can regenerate much more effectively than those of the central nervous system (CNS). This multicellular process is coordinated by peripheral glia, in particular Schwann cells, which have multiple roles in stimulating and nurturing the regrowth of damaged axons back to their targets. Aside from the repair of damaged nerves themselves, nerve regenerative processes have been linked to the repair of other tissues and de novo innervation appears important in establishing an environment conducive for the development and spread of tumors. In contrast, defects in these processes are linked to neuropathies, aging, and pain. In this review, we focus on the role of peripheral glia, especially Schwann cells, in multiple aspects of nerve regeneration and discuss how these findings may be relevant for pathologies associated with these processes.
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Affiliation(s)
- Ruth M Stassart
- Paul-Flechsig-Institute of Neuropathology, University Clinic Leipzig, Leipzig 04103, Germany
| | - Jose A Gomez-Sanchez
- Instituto de Investigación Sanitaria y Biomédica de Alicante (ISABIAL), Alicante 03010, Spain
- Instituto de Neurociencias CSIC-UMH, Sant Joan de Alicante 03550, Spain
| | - Alison C Lloyd
- UCL Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, United Kingdom
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2
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Hastings RL, Valdez G. Origin, identity, and function of terminal Schwann cells. Trends Neurosci 2024; 47:432-446. [PMID: 38664109 PMCID: PMC11168889 DOI: 10.1016/j.tins.2024.03.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 02/20/2024] [Accepted: 03/26/2024] [Indexed: 06/14/2024]
Abstract
The highly specialized nonmyelinating glial cells present at somatic peripheral nerve endings, known collectively as terminal Schwann cells (TSCs), play critical roles in the development, function and repair of their motor and sensory axon terminals and innervating tissue. Over the past decades, research efforts across various vertebrate species have revealed that while TSCs are a diverse group of cells, they share a number of features among them. In this review, we summarize the state-of-knowledge about each TSC type and explore the opportunities that TSCs provide to treat conditions that afflict peripheral axon terminals.
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Affiliation(s)
- Robert Louis Hastings
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI, USA
| | - Gregorio Valdez
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI, USA; Center for Translational Neuroscience, Robert J. and Nancy D. Carney Institute for Brain Science, and Center on the Biology of Aging, Brown University, Providence, RI, USA.
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3
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Rink-Notzon S, Reuscher J, Wollny L, Sarikcioglu L, Bilmen S, Manthou M, Gordon T, Angelov DN. Appropriate dosage, timing, and site of intramuscular injections of brain-derived neurotrophic factor (BDNF) promote motor recovery after facial nerve injury in rats. Muscle Nerve 2024; 69:490-497. [PMID: 38328996 DOI: 10.1002/mus.28051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 01/18/2024] [Accepted: 01/21/2024] [Indexed: 02/09/2024]
Abstract
INTRODUCTION/AIMS Daily intramuscular injections of fibroblast growth factor 2 (FGF2) but not of brain-derived neurotrophic factor (BDNF) significantly improve whisking behavior and mono-innervation of the rat levator labii superioris (LLS) muscle 56 days after buccal nerve transection and suture (buccal-buccal anastomosis, BBA). We explored the dose-response of BDNF, FGF2, and insulin growth factor 2 (IGF2) on the same parameters, asking whether higher doses of BDNF would promote recovery. METHODS After BBA, growth factors were injected (30 μL volume) daily into the LLS muscle over 14, 28, or 56 days. At 56 days, video-based motion analysis of vibrissal whisking was performed and the extent of mono- and poly-reinnervation of the reinnervated neuromuscular junctions (NMJs) of the muscle determined with immunostaining of the nerve with β-tubulin and histochemical staining of the endplates with Alexa Fluor 488-conjugated α-bungarotoxin. RESULTS The dose-response curve demonstrated significantly higher whisking amplitudes and corresponding increased mono-innervation of the NMJ in the reinnervated LLS muscle at concentrations of 20-30 μg/mL BDNF administered daily for 14-28 days after BBA surgery. In contrast, high doses of IGF2 and FGF2, or doses of 20 and 40 μg/mL of BDNF administered for 14-56 days had no effect on either whisking behavior or in reducing poly-reinnervation of endplates in the muscle. DISCUSSION These data suggest that the re-establishment of mono-innervation of whiskerpad muscles and the improved motor function by injections of BDNF into the paralyzed vibrissal musculature after facial nerve injury have translation potential and promote clinical application.
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Affiliation(s)
- Svenja Rink-Notzon
- Department of Prosthetic Dentistry, School of Dental and Oral Medicine, University of Cologne, Cologne, Germany
| | - Jannika Reuscher
- Department of Anatomy II, University of Cologne, Cologne, Germany
| | - Laura Wollny
- Department of Anatomy II, University of Cologne, Cologne, Germany
| | | | - Süreyya Bilmen
- Vocational School of Health Services, Akdeniz University, Antalya, Turkey
| | - Marilena Manthou
- Department of Histology and Embryology, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Tessa Gordon
- Department of Surgery, The Hospital for Sick Children, Toronto, Ontario, Canada
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4
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Hastings RL, Avila MF, Suneby E, Juros D, O'Young A, Peres da Silva J, Valdez G. Cellular and molecular evidence that synaptic Schwann cells contribute to aging of mouse neuromuscular junctions. Aging Cell 2023; 22:e13981. [PMID: 37771191 PMCID: PMC10652323 DOI: 10.1111/acel.13981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 08/17/2023] [Accepted: 08/18/2023] [Indexed: 09/30/2023] Open
Abstract
Age-induced degeneration of the neuromuscular junction (NMJ) is associated with motor dysfunction and muscle atrophy. While the impact of aging on the NMJ presynapse and postsynapse is well-documented, little is known about the changes perisynaptic Schwann cells (PSCs), the synaptic glia of the NMJ, undergo during aging. Here, we examined PSCs in young, middle-aged, and old mice in three muscles with different susceptibility to aging. Using light and electron microscopy, we found that PSCs acquire age-associated cellular features either prior to or at the same time as the onset of NMJ degeneration. Notably, we found that aged PSCs fail to completely cap the NMJ even though they are more abundant in old compared with young mice. We also found that aging PSCs form processes that either intrude into the synaptic cleft or guide axonal sprouts to innervate other NMJs. We next profiled the transcriptome of PSCs and other Schwann cells (SCs) to identify mechanisms altered in aged PSCs. This analysis revealed that aged PSCs acquire a transcriptional pattern previously shown to promote phagocytosis that is absent in other SCs. It also showed that aged PSCs upregulate unique pro-inflammatory molecules compared to other aged SCs. Interestingly, neither synaptogenesis genes nor genes that are typically upregulated by repair SCs were induced in aged PSCs or other SCs. These findings provide insights into cellular and molecular mechanisms that could be targeted in PSCs to stave off the deleterious effects of aging on NMJs.
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Affiliation(s)
- Robert Louis Hastings
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, Rhode Island, USA
| | | | - Emma Suneby
- Molecular Biology, Cell Biology, & Biochemistry Graduate Program, Brown University, Providence, Rhode Island, USA
| | - Devin Juros
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, Rhode Island, USA
| | - Anson O'Young
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, Rhode Island, USA
| | - Jason Peres da Silva
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, Rhode Island, USA
| | - Gregorio Valdez
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, Rhode Island, USA
- Center for Translational Neuroscience, Robert J. and Nancy D. Carney Institute for Brain Science, and Center on the Biology of Aging, Brown University, Providence, Rhode Island, USA
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5
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Personius KE, Siebert D, Koch DW, Udin SB. Blockage of neuromuscular glutamate receptors impairs reinnervation following nerve crush in adult mice. Front Cell Neurosci 2022; 16:1000218. [PMID: 36212695 PMCID: PMC9535682 DOI: 10.3389/fncel.2022.1000218] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 09/02/2022] [Indexed: 11/29/2022] Open
Abstract
Motor axons in peripheral nerves are capable of regeneration following injury. However, complete recovery of motor function is rare, particularly when reinnervation is delayed. We have previously found that glutamate receptors play a crucial role in the successful innervation of muscle during mouse development. In particular, blocking N-methyl-D-aspartate (NMDA) receptor activity delays the normal elimination of excess innervation of each neuromuscular junction. Here, we use behavioral, immunohistochemical, electrophysiological, and calcium imaging methods to test whether glutamate receptors play a similar role in the transition from polyneuronal to mono-innervation and in recovery of function following peripheral nerve injury in mature muscle.
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Affiliation(s)
- Kirkwood E. Personius
- Program in Neuroscience, School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, United States
- Department of Rehabilitation Science, School of Public Health and Health Professions, University at Buffalo, Buffalo, NY, United States
- *Correspondence: Kirkwood E. Personius,
| | - Danielle Siebert
- Program in Neuroscience, School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, United States
| | - Dennis W. Koch
- Department of Kinesiology, Canisius College, Buffalo, NY, United States
| | - Susan B. Udin
- Program in Neuroscience, School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, United States
- Department of Physiology and Biophysics, School of Medicine and Biomedical Sciences, Buffalo, NY, United States
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6
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Perez-Gonzalez AP, Provost F, Rousse I, Piovesana R, Benzina O, Darabid H, Lamoureux B, Wang YS, Arbour D, Robitaille R. Functional adaptation of glial cells at neuromuscular junctions in response to injury. Glia 2022; 70:1605-1629. [PMID: 35474470 PMCID: PMC9543218 DOI: 10.1002/glia.24184] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 04/14/2022] [Accepted: 04/18/2022] [Indexed: 12/04/2022]
Abstract
Synaptic elements from neuromuscular junctions (NMJs) undergo massive morphological and functional changes upon nerve injury. While morphological changes of NMJ‐associated glia in response to injury has been investigated, their functional properties remain elusive. Perisynaptic Schwann cells (PSCs), glial cells at the NMJ, are essential for NMJ maintenance and repair, and are involved in synaptic efficacy and plasticity. Importantly, these functions are regulated by PSCs ability to detect synaptic transmission through, notably, muscarinic (mAChRs) and purinergic receptors' activation. Using Ca2+ imaging and electrophysiological recordings of synaptic transmission at the mouse NMJ, we investigated PSC receptors activation following denervation and during reinnervation in adults and at denervated NMJs in an ALS mouse model (SOD1G37R). We observed reduced PSCs mAChR‐mediated Ca2+ responses at denervated and reinnervating NMJs. Importantly, PSC phenotypes during denervation and reinnervation were distinct than the one observed during NMJ maturation. At denervated NMJs, exogenous activation of mAChRs greatly diminished galectin‐3 expression, a glial marker of phagocytosis. PSCs Ca2+ responses at reinnervating NMJs did not correlate with the number of innervating axons or process extensions. Interestingly, we observed an extended period of reduced PSC mAChRs activation after the injury (up to 60 days), suggesting a glial memory of injury. PSCs associated with denervated NMJs in an ALS model (SOD1G37R mice) did not show any muscarinic adaptation, a phenotype incompatible with NMJ repair. Understanding functional mechanisms that underlie this glial response to injury may contribute to favor complete NMJ and motor recovery.
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Affiliation(s)
- Anna P Perez-Gonzalez
- Département de Neurosciences, Université de Montréal, Montréal, Québec, Canada.,Groupe de Recherche sur le Système Nerveux Central, Université de Montréal, Montréal, Québec, Canada
| | - Frédéric Provost
- Département de Neurosciences, Université de Montréal, Montréal, Québec, Canada.,Groupe de Recherche sur le Système Nerveux Central, Université de Montréal, Montréal, Québec, Canada
| | - Isabelle Rousse
- Département de Neurosciences, Université de Montréal, Montréal, Québec, Canada.,Groupe de Recherche sur le Système Nerveux Central, Université de Montréal, Montréal, Québec, Canada
| | - Roberta Piovesana
- Département de Neurosciences, Université de Montréal, Montréal, Québec, Canada.,Groupe de Recherche sur le Système Nerveux Central, Université de Montréal, Montréal, Québec, Canada
| | - Ouafa Benzina
- Département de Neurosciences, Université de Montréal, Montréal, Québec, Canada.,Groupe de Recherche sur le Système Nerveux Central, Université de Montréal, Montréal, Québec, Canada
| | - Houssam Darabid
- Département de Neurosciences, Université de Montréal, Montréal, Québec, Canada.,Groupe de Recherche sur le Système Nerveux Central, Université de Montréal, Montréal, Québec, Canada
| | - Benoit Lamoureux
- Département de Neurosciences, Université de Montréal, Montréal, Québec, Canada.,Groupe de Recherche sur le Système Nerveux Central, Université de Montréal, Montréal, Québec, Canada
| | - Yu Shi Wang
- Département de Neurosciences, Université de Montréal, Montréal, Québec, Canada.,Groupe de Recherche sur le Système Nerveux Central, Université de Montréal, Montréal, Québec, Canada
| | - Danielle Arbour
- Département de Neurosciences, Université de Montréal, Montréal, Québec, Canada.,Groupe de Recherche sur le Système Nerveux Central, Université de Montréal, Montréal, Québec, Canada
| | - Richard Robitaille
- Département de Neurosciences, Université de Montréal, Montréal, Québec, Canada.,Groupe de Recherche sur le Système Nerveux Central, Université de Montréal, Montréal, Québec, Canada.,Centre Interdisciplinaire de Recherche sur le Cerveau et l'apprentissage, Montréal, Québec, Canada
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7
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Huang X, Jiang J, Xu J. Denervation-Related Neuromuscular Junction Changes: From Degeneration to Regeneration. Front Mol Neurosci 2022; 14:810919. [PMID: 35282655 PMCID: PMC8908450 DOI: 10.3389/fnmol.2021.810919] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 12/30/2021] [Indexed: 11/13/2022] Open
Abstract
Neuromuscular junctions (NMJs) are the key interface between terminal nerves and targeted muscle, which undergo degeneration during denervation periods. Denervation-related NMJs changes limits the recovery level of nerve repair strategies. Insights into mechanisms behind neuromuscular junction degeneration and regeneration, following denervation and reinnervation, are of clinical value. Developing some therapies to maintain or protect structures and functions of NMJs may contribute to a better prognosis. Here, we reviewed previous studies of NMJs focusing on the morphological, functional, and molecular changes after denervation, and if those changes can be reversed after reinnervation. Also, we reviewed about the present probable strategies that have been applied clinically or could still be studied in targeting the neuromuscular junction protection or regeneration improvement.
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Affiliation(s)
- Xinying Huang
- Department of Hand Surgery, Huashan Hospital, Fudan University, Shanghai, China
- Shanghai Medical College, Fudan University, Shanghai, China
- Key Laboratory of Hand Reconstruction, Ministry of Health, Shanghai, China
- Shanghai Key Laboratory of Peripheral Nerve and Microsurgery, Shanghai, China
| | - Junjian Jiang
- Department of Hand Surgery, Huashan Hospital, Fudan University, Shanghai, China
- Key Laboratory of Hand Reconstruction, Ministry of Health, Shanghai, China
- Shanghai Key Laboratory of Peripheral Nerve and Microsurgery, Shanghai, China
- *Correspondence: Junjian Jiang,
| | - Jianguang Xu
- Department of Hand Surgery, Huashan Hospital, Fudan University, Shanghai, China
- Key Laboratory of Hand Reconstruction, Ministry of Health, Shanghai, China
- Shanghai Key Laboratory of Peripheral Nerve and Microsurgery, Shanghai, China
- Jianguang Xu,
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8
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Gustafsson T, Ulfhake B. Sarcopenia: What Is the Origin of This Aging-Induced Disorder? Front Genet 2021; 12:688526. [PMID: 34276788 PMCID: PMC8285098 DOI: 10.3389/fgene.2021.688526] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 05/10/2021] [Indexed: 01/03/2023] Open
Abstract
We here review the loss of muscle function and mass (sarcopenia) in the framework of human healthspan and lifespan, and mechanisms involved in aging. The rapidly changing composition of the human population will impact the incidence and the prevalence of aging-induced disorders such as sarcopenia and, henceforth, efforts to narrow the gap between healthspan and lifespan should have top priority. There are substantial knowledge gaps in our understanding of aging. Heritability is estimated to account for only 25% of lifespan length. However, as we push the expected lifespan at birth toward those that we consider long-lived, the genetics of aging may become increasingly important. Linkage studies of genetic polymorphisms to both the susceptibility and aggressiveness of sarcopenia are still missing. Such information is needed to shed light on the large variability in clinical outcomes between individuals and why some respond to interventions while others do not. We here make a case for the concept that sarcopenia has a neurogenic origin and that in manifest sarcopenia, nerve and myofibers enter into a vicious cycle that will escalate the disease progression. We point to gaps in knowledge, for example the crosstalk between the motor axon, terminal Schwann cell, and myofiber in the denervation processes that leads to a loss of motor units and muscle weakness. Further, we argue that the operational definition of sarcopenia should be complemented with dynamic metrics that, along with validated biomarkers, may facilitate early preclinical diagnosis of individuals vulnerable to develop advanced sarcopenia. We argue that preventive measures are likely to be more effective to counter act aging-induced disorders than efforts to treat manifest clinical conditions. To achieve compliance with a prescription of preventive measures that may be life-long, we need to identify reliable predictors to design rational and convincing interventions.
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Affiliation(s)
- Thomas Gustafsson
- Division of Clinical Physiology, Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Brun Ulfhake
- Division of Clinical Physiology, Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
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9
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Fuertes-Alvarez S, Izeta A. Terminal Schwann Cell Aging: Implications for Age-Associated Neuromuscular Dysfunction. Aging Dis 2021; 12:494-514. [PMID: 33815879 PMCID: PMC7990373 DOI: 10.14336/ad.2020.0708] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 07/08/2020] [Indexed: 12/11/2022] Open
Abstract
Action potential is transmitted to muscle fibers through specialized synaptic interfaces called neuromuscular junctions (NMJs). These structures are capped by terminal Schwann cells (tSCs), which play essential roles during formation and maintenance of the NMJ. tSCs are implicated in the correct communication between nerves and muscles, and in reinnervation upon injury. During aging, loss of muscle mass and strength (sarcopenia and dynapenia) are due, at least in part, to the progressive loss of contacts between muscle fibers and nerves. Despite the important role of tSCs in NMJ function, very little is known on their implication in the NMJ-aging process and in age-associated denervation. This review summarizes the current knowledge about the implication of tSCs in the age-associated degeneration of NMJs. We also speculate on the possible mechanisms underlying the observed phenotypes.
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Affiliation(s)
- Sandra Fuertes-Alvarez
- 1Biodonostia, Tissue Engineering Group, Paseo Dr. Begiristain, s/n, San Sebastian 20014, Spain
| | - Ander Izeta
- 1Biodonostia, Tissue Engineering Group, Paseo Dr. Begiristain, s/n, San Sebastian 20014, Spain.,2Tecnun-University of Navarra, School of Engineering, Department of Biomedical Engineering and Science, Paseo Mikeletegi, 48, San Sebastian 20009, Spain
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10
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Zelada D, Bermedo-García F, Collao N, Henríquez JP. Motor function recovery: deciphering a regenerative niche at the neuromuscular synapse. Biol Rev Camb Philos Soc 2020; 96:752-766. [PMID: 33336525 PMCID: PMC7986695 DOI: 10.1111/brv.12675] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 11/20/2020] [Accepted: 11/25/2020] [Indexed: 12/13/2022]
Abstract
The coordinated movement of many organisms relies on efficient nerve–muscle communication at the neuromuscular junction (NMJ), a peripheral synapse composed of a presynaptic motor axon terminal, a postsynaptic muscle specialization, and non‐myelinating terminal Schwann cells. NMJ dysfunctions are caused by traumatic spinal cord or peripheral nerve injuries as well as by severe motor pathologies. Compared to the central nervous system, the peripheral nervous system displays remarkable regenerating abilities; however, this capacity is limited by the denervation time frame and depends on the establishment of permissive regenerative niches. At the injury site, detailed information is available regarding the cells, molecules, and mechanisms involved in nerve regeneration and repair. However, a regenerative niche at the final functional step of peripheral motor innervation, i.e. at the mature neuromuscular synapse, has not been deciphered. In this review, we integrate classic and recent evidence describing the cells and molecules that could orchestrate a dynamic ecosystem to accomplish successful NMJ regeneration. We propose that such a regenerative niche must ensure at least two fundamental steps for successful NMJ regeneration: the proper arrival of incoming regenerating axons to denervated postsynaptic muscle domains, and the resilience of those postsynaptic domains, in morphological and functional terms. We here describe and combine the main cellular and molecular responses involved in each of these steps as potential targets to help successful NMJ regeneration.
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Affiliation(s)
- Diego Zelada
- Neuromuscular Studies Laboratory (NeSt Lab), Department of Cell Biology, Faculty of Biological Sciences, Center for Advanced Microscopy (CMA Bio-Bio), Universidad de Concepción, Casilla 160-C, Concepción, Chile
| | - Francisca Bermedo-García
- Neuromuscular Studies Laboratory (NeSt Lab), Department of Cell Biology, Faculty of Biological Sciences, Center for Advanced Microscopy (CMA Bio-Bio), Universidad de Concepción, Casilla 160-C, Concepción, Chile
| | - Nicolás Collao
- Neuromuscular Studies Laboratory (NeSt Lab), Department of Cell Biology, Faculty of Biological Sciences, Center for Advanced Microscopy (CMA Bio-Bio), Universidad de Concepción, Casilla 160-C, Concepción, Chile
| | - Juan P Henríquez
- Neuromuscular Studies Laboratory (NeSt Lab), Department of Cell Biology, Faculty of Biological Sciences, Center for Advanced Microscopy (CMA Bio-Bio), Universidad de Concepción, Casilla 160-C, Concepción, Chile
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11
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Lago-Baldaia I, Fernandes VM, Ackerman SD. More Than Mortar: Glia as Architects of Nervous System Development and Disease. Front Cell Dev Biol 2020; 8:611269. [PMID: 33381506 PMCID: PMC7767919 DOI: 10.3389/fcell.2020.611269] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 11/17/2020] [Indexed: 12/12/2022] Open
Abstract
Glial cells are an essential component of the nervous system of vertebrates and invertebrates. In the human brain, glia are as numerous as neurons, yet the importance of glia to nearly every aspect of nervous system development has only been expounded over the last several decades. Glia are now known to regulate neural specification, synaptogenesis, synapse function, and even broad circuit function. Given their ubiquity, it is not surprising that the contribution of glia to neuronal disease pathogenesis is a growing area of research. In this review, we will summarize the accumulated evidence of glial participation in several distinct phases of nervous system development and organization-neural specification, circuit wiring, and circuit function. Finally, we will highlight how these early developmental roles of glia contribute to nervous system dysfunction in neurodevelopmental and neurodegenerative disorders.
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Affiliation(s)
- Inês Lago-Baldaia
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Vilaiwan M. Fernandes
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Sarah D. Ackerman
- Institute of Neuroscience, Howard Hughes Medical Institute, University of Oregon, Eugene, OR, United States
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12
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Gordon T. Peripheral Nerve Regeneration and Muscle Reinnervation. Int J Mol Sci 2020; 21:ijms21228652. [PMID: 33212795 PMCID: PMC7697710 DOI: 10.3390/ijms21228652] [Citation(s) in RCA: 117] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 11/06/2020] [Accepted: 11/10/2020] [Indexed: 12/24/2022] Open
Abstract
Injured peripheral nerves but not central nerves have the capacity to regenerate and reinnervate their target organs. After the two most severe peripheral nerve injuries of six types, crush and transection injuries, nerve fibers distal to the injury site undergo Wallerian degeneration. The denervated Schwann cells (SCs) proliferate, elongate and line the endoneurial tubes to guide and support regenerating axons. The axons emerge from the stump of the viable nerve attached to the neuronal soma. The SCs downregulate myelin-associated genes and concurrently, upregulate growth-associated genes that include neurotrophic factors as do the injured neurons. However, the gene expression is transient and progressively fails to support axon regeneration within the SC-containing endoneurial tubes. Moreover, despite some preference of regenerating motor and sensory axons to “find” their appropriate pathways, the axons fail to enter their original endoneurial tubes and to reinnervate original target organs, obstacles to functional recovery that confront nerve surgeons. Several surgical manipulations in clinical use, including nerve and tendon transfers, the potential for brief low-frequency electrical stimulation proximal to nerve repair, and local FK506 application to accelerate axon outgrowth, are encouraging as is the continuing research to elucidate the molecular basis of nerve regeneration.
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Affiliation(s)
- Tessa Gordon
- Department of Surgery, University of Toronto, Division of Plastic Reconstructive Surgery, 06.9706 Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada
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13
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Lee YI, Rimer M. Wesley J. Thompson (1947-2019). Front Mol Neurosci 2020; 13:91. [PMID: 32595450 PMCID: PMC7303338 DOI: 10.3389/fnmol.2020.00091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 04/30/2020] [Indexed: 11/16/2022] Open
Affiliation(s)
- Young Il Lee
- Department of Biology, Texas A&M University, College Station, TX, United States
| | - Mendell Rimer
- Department of Neuroscience and Experimental Therapeutics, Texas A&M University Health Science Center, Bryan, TX, United States
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14
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Rink S, Chatziparaskeva C, Elles L, Pavlov S, Nohroudi K, Bendella H, Sarikcioglu L, Manthou M, Dunlop S, Gordon T, Angelov DN. Neutralizing
BDNF
and
FGF2
injection into denervated skeletal muscle improve recovery after nerve repair. Muscle Nerve 2020; 62:404-412. [DOI: 10.1002/mus.26991] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 05/22/2020] [Accepted: 05/30/2020] [Indexed: 12/18/2022]
Affiliation(s)
- Svenja Rink
- Department of Prosthetic Dentistry, School of Dental and Oral MedicineUniversity of Cologne Germany
| | | | - Luisa Elles
- Department of Anatomy IUniversity of Cologne Germany
| | - Stoyan Pavlov
- Department of Anatomy, Histology and EmbryologyMedical University Varna Bulgaria
| | | | - Habib Bendella
- Department of NeurosurgeryUniversity of Witten/Herdecke, Cologne Merheim Medical Center (CMMC) Cologne Germany
| | | | - Marilena Manthou
- Department of Histology and EmbryologyAristotle University Thessaloniki Greece
| | - Sarah Dunlop
- School of Biological SciencesThe University of Western Australia Australia
| | - Tessa Gordon
- Department of SurgeryThe Hospital for Sick Children Toronto Ontario Canada
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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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Chan JP, Clune J, Shah SB, Ward SR, Kocsis JD, Mozaffar T, Steward O, Gupta R. Examination of the human motor endplate after brachial plexus injury with two-photon microscopy. Muscle Nerve 2019; 61:390-395. [PMID: 31820462 DOI: 10.1002/mus.26778] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 11/28/2019] [Accepted: 12/03/2019] [Indexed: 12/12/2022]
Abstract
INTRODUCTION After traumatic nerve injury, neuromuscular junction remodeling plays a key role in determining functional outcomes. Immunohistochemical analyses of denervated muscle biopsies may provide valuable prognostic data regarding clinical outcomes to supplement electrodiagnostic studies. METHODS We performed biopsies on nonfunctioning deltoid muscles in two patients after gunshot wounds and visualized the neuromuscular junctions using two-photon microscopy with immunohistochemistry. RESULTS Although the nerves in both patients showed evidence of acute Wallerian degeneration, some of the motor endplates were intact but exhibited significantly decreased surface area and volume. Both patients exhibited substantial recovery of motor function over several weeks postinjury. DISCUSSION Two-photon microscopic assessment of neuromuscular junction integrity and motor endplate morphometry in muscle biopsies provided evidence of partial sparing of muscle innervation. This finding supported the clinical judgment that eventual recovery would occur. With further study, this technique may help to guide operative decisionmaking after traumatic nerve injuries.
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Affiliation(s)
- Justin P Chan
- Department of Orthopaedic Surgery, University of California, Irvine, California
| | - James Clune
- Section of Plastic and Reconstructive Surgery, Yale University School of Medicine, New Haven, Connecticut
| | - Sameer B Shah
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, California.,Department of Bioengineering, University of California, San Diego, La Jolla, California
| | - Samuel R Ward
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, California.,Department of Bioengineering, University of California, San Diego, La Jolla, California
| | - Jeffery D Kocsis
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut
| | - Tahseen Mozaffar
- Department of Neurology, University of California, Irvine, Irvine, California
| | - Oswald Steward
- Reeve-Irvine Research Center, University of California, Irvine, Irvine, California
| | - Ranjan Gupta
- Department of Orthopaedic Surgery, University of California, Irvine, California
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17
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Abstract
Toxic peripheral neuropathies are an important form of acquired polyneuropathy produced by a variety of xenobiotics and different exposure scenarios. Delineating the mechanisms of neurotoxicants and determining the degenerative biological pathways triggered by peripheral neurotoxicants will facilitate the development of sensitive and specific biochemical-based methods for identifying neurotoxicants, designing therapeutic interventions, and developing structure-activity relationships for predicting potential neurotoxicants. This review presents an overview of the general concepts of toxic peripheral neuropathies with the goal of providing insight into why certain agents target the peripheral nervous system and produce their associated lesions. Experimental data and the main hypotheses for the mechanisms of selected agents that produce neuronopathies, axonopathies, or myelinopathies including covalent or noncovalent modifications, compromised energy or protein biosynthesis, and oxidative injury and disruption of ionic gradients across membranes are presented. The relevance of signaling between the main components of peripheral nerve, that is, glia, neuronal perikaryon, and axon, as a target for neurotoxicants and the contribution of active programmed degenerative pathways to the lesions observed in toxic peripheral neuropathies is also discussed.
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