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Morton AB, Jacobsen NL, Diller AR, Kendra JA, Golpasandi S, Cornelison DDW, Segal SS. Inducible deletion of endothelial cell Efnb2 delays capillary regeneration and attenuates myofibre reinnervation following myotoxin injury in mice. J Physiol 2024; 602:4907-4927. [PMID: 39196901 PMCID: PMC11466691 DOI: 10.1113/jp285402] [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: 07/29/2023] [Accepted: 07/22/2024] [Indexed: 08/30/2024] Open
Abstract
Acute injury of skeletal muscle disrupts myofibres, microvessels and motor innervation. Myofibre regeneration is well characterized, however its relationship with the regeneration of microvessels and motor nerves is undefined. Endothelial cell (EC) ephrin-B2 (Efnb2) is required for angiogenesis during embryonic development and promotes neurovascular regeneration in the adult. We hypothesized that, following acute injury to skeletal muscle, loss of EC Efnb2 would impair microvascular regeneration and the recovery of neuromuscular junction (NMJ) integrity. Mice (aged 3-6 months) were bred for EC-specific conditional knockout (CKO) of Efnb2 following tamoxifen injection with non-injected CKO mice as controls (CON). The gluteus maximus, tibialis anterior or extensor digitorum longus muscle was then injured with local injection of BaCl2. Intravascular staining with wheat germ agglutinin revealed diminished capillary area in the gluteus maximus of CKO vs. CON at 5 days post-injury (dpi); both recovered to uninjured (0 dpi) level by 10 dpi. At 0 dpi, tibialis anterior isometric force of CKO was less than CON. At 10 dpi, isometric force was reduced by half in both groups. During intermittent contractions (75 Hz, 330 ms s-1, 120 s), isometric force fell during indirect (sciatic nerve) stimulation whereas force was maintained during direct (electrical field) stimulation of myofibres. Neuromuscular transmission failure correlated with perturbed presynaptic (terminal Schwann cells) and postsynaptic (nicotinic acetylcholine receptors) NMJ morphology in CKO. Resident satellite cell number on extensor digitorum longus myofibres did not differ between groups. Following acute injury of skeletal muscle, loss of Efnb2 in ECs delays capillary regeneration and attenuates recovery of NMJ structure and function. KEY POINTS: The relationship between microvascular regeneration and motor nerve regeneration following skeletal muscle injury is undefined. Expression of Efnb2 in endothelial cells (ECs) is essential to vascular development and promotes neurovascular regeneration in the adult. To test the hypothesis that EfnB2 in ECs is required for microvascular regeneration and myofibre reinnervation, we induced conditional knockout of Efnb2 in ECs of mice. Acute injury was then induced by BaCl2 injection into gluteus maximus, tibialis anterior or extensor digitorum longus (EDL) muscle. Capillary regeneration was reduced at 5 days post-injury (dpi) in gluteus maximus of conditional knockout vs. controls; at 10 dpi, neither differed from uninjured. Nerve stimulation revealed neuromuscular transmission failure in tibialis anterior with perturbed neuromuscular junction structure. Resident satellite cell number on EDL myofibres did not differ between groups. Conditional knockout of EC Efnb2 delays capillary regeneration and attenuates recovery of neuromuscular junction structure and function.
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Affiliation(s)
- Aaron B. Morton
- Department of Kinesiology and Sport Management, Texas A&M University, College Station, TX, 77845
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO, 65212
| | - Nicole L. Jacobsen
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO, 65212
| | | | - Jacob A. Kendra
- Department of Kinesiology and Sport Management, Texas A&M University, College Station, TX, 77845
| | - Shadi Golpasandi
- Department of Kinesiology and Sport Management, Texas A&M University, College Station, TX, 77845
| | - DDW Cornelison
- Division of Biological Sciences, University of Missouri, Columbia, MO 65211
- Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, MO 65211
| | - Steven S. Segal
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO, 65212
- Dalton Cardiovascular Research Center, Columbia, MO 65211
- Department of Biomedical Sciences, University of Missouri; Columbia, MO 65201
- Department of Biomedical, Biological, and Chemical Engineering, University of Missouri; Columbia, MO 65211
- Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, MO 65211
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2
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Juros D, Avila MF, Hastings RL, Pendragon A, Wilson L, Kay J, Valdez G. Cellular and molecular alterations to muscles and neuromuscular synapses in a mouse model of MEGF10-related myopathy. Skelet Muscle 2024; 14:10. [PMID: 38760872 PMCID: PMC11100254 DOI: 10.1186/s13395-024-00342-6] [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: 02/27/2024] [Accepted: 05/04/2024] [Indexed: 05/19/2024] Open
Abstract
Loss-of-function mutations in MEGF10 lead to a rare and understudied neuromuscular disorder known as MEGF10-related myopathy. There are no treatments for the progressive respiratory distress, motor impairment, and structural abnormalities in muscles caused by the loss of MEGF10 function. In this study, we deployed cellular and molecular assays to obtain additional insights about MEGF10-related myopathy in juvenile, young adult, and middle-aged Megf10 knockout (KO) mice. We found fewer muscle fibers in juvenile and adult Megf10 KO mice, supporting published studies that MEGF10 regulates myogenesis by affecting satellite cell differentiation. Interestingly, muscle fibers do not exhibit morphological hallmarks of atrophy in either young adult or middle-aged Megf10 KO mice. We next examined the neuromuscular junction (NMJ), in which MEGF10 has been shown to concentrate postnatally, using light and electron microscopy. We found early and progressive degenerative features at the NMJs of Megf10 KO mice that include increased postsynaptic fragmentation and presynaptic regions not apposed by postsynaptic nicotinic acetylcholine receptors. We also found perisynaptic Schwann cells intruding into the NMJ synaptic cleft. These findings strongly suggest that the NMJ is a site of postnatal pathology in MEGF10-related myopathy. In support of these cellular observations, RNA-seq analysis revealed genes and pathways associated with myogenesis, skeletal muscle health, and NMJ stability dysregulated in Megf10 KO mice compared to wild-type mice. Altogether, these data provide new and valuable cellular and molecular insights into MEGF10-related myopathy.
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Affiliation(s)
- Devin Juros
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, 70 Ship St, Providence, RI, 02903, USA
| | | | - Robert Louis Hastings
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, 70 Ship St, Providence, RI, 02903, USA
| | - Ariane Pendragon
- Department of Neurobiology, Duke University School of Medicine, Durham, NC, USA
| | - Liam Wilson
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, 70 Ship St, Providence, RI, 02903, USA
| | - Jeremy Kay
- Department of Neurobiology, Duke University School of Medicine, Durham, NC, USA
- Department of Ophthalmology, Duke University School of Medicine, Durham, NC, USA
| | - Gregorio Valdez
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, 70 Ship St, Providence, RI, 02903, USA.
- Center for Translational Neuroscience, Robert J. and Nancy D. Carney Institute for Brain Science, Center on the Biology of Aging, Brown University, Providence, RI, USA.
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3
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Guzman SD, Abu-Mahfouz A, Davis CS, Ruiz LP, Macpherson PC, Brooks SV. Decoding muscle-resident Schwann cell dynamics during neuromuscular junction remodeling. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.06.561193. [PMID: 38370853 PMCID: PMC10871306 DOI: 10.1101/2023.10.06.561193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
Understanding neuromuscular junction (NMJ) repair mechanisms is essential for addressing degenerative neuromuscular conditions. Here, we focus on the role of muscle-resident Schwann cells in NMJ reinnervation. In young Sod1-/- mice, a model of progressive NMJ degeneration, we identified a clear NMJ 'regenerative window' that allowed us to define regulators of reinnervation and crossing Sod1-/- mice with S100GFP-tg mice permitted visualization and analysis of Schwann cells. High-resolution imaging and single-cell RNA sequencing provide a detailed analysis of Schwann cell number, morphology, and transcriptome revealing multiple subtypes, including a previously unrecognized terminal Schwann cell (tSC) population expressing a synapse promoting signature. We also discovered a novel SPP1-driven cellular interaction between myelin Schwann cells and tSCs and show that it promotes tSC proliferation and reinnervation following nerve injury in wild type mice. Our findings offer important insights into molecular regulators critical in NMJ reinnervation that are mediated through tSCs to maintain NMJ function.
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Affiliation(s)
- Steve D Guzman
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, USA
| | - Ahmad Abu-Mahfouz
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA
| | - Carol S Davis
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA
| | - Lloyd P Ruiz
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA
| | - Peter C Macpherson
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA
| | - Susan V Brooks
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
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Mihailova V, Stoyanova II, Tonchev AB. Glial Populations in the Human Brain Following Ischemic Injury. Biomedicines 2023; 11:2332. [PMID: 37760773 PMCID: PMC10525766 DOI: 10.3390/biomedicines11092332] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 08/14/2023] [Accepted: 08/19/2023] [Indexed: 09/29/2023] Open
Abstract
There is a growing interest in glial cells in the central nervous system due to their important role in maintaining brain homeostasis under physiological conditions and after injury. A significant amount of evidence has been accumulated regarding their capacity to exert either pro-inflammatory or anti-inflammatory effects under different pathological conditions. In combination with their proliferative potential, they contribute not only to the limitation of brain damage and tissue remodeling but also to neuronal repair and synaptic recovery. Moreover, reactive glial cells can modulate the processes of neurogenesis, neuronal differentiation, and migration of neurons in the existing neural circuits in the adult brain. By discovering precise signals within specific niches, the regulation of sequential processes in adult neurogenesis holds the potential to unlock strategies that can stimulate the generation of functional neurons, whether in response to injury or as a means of addressing degenerative neurological conditions. Cerebral ischemic stroke, a condition falling within the realm of acute vascular disorders affecting the circulation in the brain, stands as a prominent global cause of disability and mortality. Extensive investigations into glial plasticity and their intricate interactions with other cells in the central nervous system have predominantly relied on studies conducted on experimental animals, including rodents and primates. However, valuable insights have also been gleaned from in vivo studies involving poststroke patients, utilizing highly specialized imaging techniques. Following the attempts to map brain cells, the role of various transcription factors in modulating gene expression in response to cerebral ischemia is gaining increasing popularity. Although the results obtained thus far remain incomplete and occasionally ambiguous, they serve as a solid foundation for the development of strategies aimed at influencing the recovery process after ischemic brain injury.
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Affiliation(s)
- Victoria Mihailova
- Department of Anatomy and Cell Biology, Faculty of Medicine, Medical University Varna, 9000 Varna, Bulgaria; (I.I.S.); (A.B.T.)
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5
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Arpke RW, Moritz TC, Hahn KL, Stark DA, Villalón E, Lorson CL, Cornelison DDW. Normal muscle fiber type distribution is recapitulated in aged ephrin-A3 -/- mice that previously lacked most slow myofibers. Am J Physiol Cell Physiol 2023; 324:C718-C727. [PMID: 36717102 PMCID: PMC10027087 DOI: 10.1152/ajpcell.00519.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 01/18/2023] [Accepted: 01/19/2023] [Indexed: 02/01/2023]
Abstract
Individual limb muscles have characteristic representation and spatial distribution of muscle fiber types (one slow and up to three fast isoforms) appropriate to their unique anatomical location and function. This distribution can be altered by physiological stimuli such as training (i.e., for increased endurance or force) or pathological conditions such as aging. Our group previously showed that ephrin-A3 is expressed only on slow myofibers, and that adult mice lacking ephrin-A3 have dramatically reduced numbers of slow myofibers due to postnatal innervation of previously slow myofibers by fast motor neurons. In this study, fiber type composition of hindlimb muscles of aged and denervated/reinnervated C57BL/6 and ephrin-A3-/- mice was analyzed to determine whether the loss of slow myofibers persists across the lifespan. Surprisingly, fiber-type composition of ephrin-A3-/- mouse muscles at two years of age was nearly indistinguishable from age-matched C57BL/6 mice. After challenge with nerve crush, the percentage of IIa and I/IIa hybrid myofibers increased significantly in aged ephrin-A3-/- mice. While EphA8, the receptor for ephrin-A3, is present at all neuromuscular junctions (NMJs) on fast fibers in 3-6 mo old C57BL/6 and ephrin-A3-/- mice, this exclusive localization is lost with aging, with EphA8 expression now found on a subset of NMJs on some slow muscle fibers. This return to appropriate fiber-type distribution given time and under use reinforces the role of activity in determining fiber-type representation and suggests that, rather than being a passive baseline, the developmentally and evolutionarily selected fiber type pattern may instead be actively reinforced by daily living.
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Affiliation(s)
- Robert W. Arpke
- Division of Biological Sciences, University of Missouri, Columbia, Missouri, United States
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, Missouri, United States
| | - Timothy C. Moritz
- Division of Biological Sciences, University of Missouri, Columbia, Missouri, United States
| | - Kevin L. Hahn
- Division of Biological Sciences, University of Missouri, Columbia, Missouri, United States
| | - Danny A. Stark
- Division of Biological Sciences, University of Missouri, Columbia, Missouri, United States
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, Missouri, United States
| | - Eric Villalón
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, Missouri, United States
| | - Christian L. Lorson
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, Missouri, United States
| | - DDW Cornelison
- Division of Biological Sciences, University of Missouri, Columbia, Missouri, United States
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, Missouri, United States
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6
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Cunningham ME, McGonigal R, Barrie JA, Campbell CI, Yao D, Willison HJ. Axolemmal nanoruptures arising from paranodal membrane injury induce secondary axon degeneration in murine Guillain-Barré syndrome. J Peripher Nerv Syst 2023; 28:17-31. [PMID: 36710500 PMCID: PMC10947354 DOI: 10.1111/jns.12532] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 01/19/2023] [Accepted: 01/23/2023] [Indexed: 01/31/2023]
Abstract
The major determinant of poor outcome in Guillain-Barré syndrome (GBS) is axonal degeneration. Pathways leading to primary axonal injury in the motor axonal variant are well established, whereas mechanisms of secondary axonal injury in acute inflammatory demyelinating polyneuropathy (AIDP) are unknown. We recently developed an autoantibody-and complement-mediated model of murine AIDP, in which prominent injury to glial membranes at the node of Ranvier results in severe disruption to paranodal components. Acutely, axonal integrity was maintained, but over time secondary axonal degeneration occurred. Herein, we describe the differential mechanisms underlying acute glial membrane injury and secondary axonal injury in this model. Ex vivo nerve-muscle explants were injured for either acute or extended periods with an autoantibody-and complement-mediated injury to glial paranodal membranes. This model was used to test several possible mechanisms of axon degeneration including calpain activation, and to monitor live axonal calcium signalling. Glial calpains induced acute disruption of paranodal membrane proteins in the absence of discernible axonal injury. Over time, we observed progressive axonal degeneration which was markedly attenuated by axon-specific calpain inhibition. Injury was unaffected by all other tested methods of protection. Trans-axolemmal diffusion of fluorescent proteins and live calcium imaging studies indirectly demonstrated the presence of nanoruptures in the axon membrane. This study outlines one mechanism by which secondary axonal degeneration arises in the AIDP variant of GBS where acute paranodal loop injury is prominent. The data also support the development of calpain inhibitors to attenuate both primary and secondary axonal degeneration in GBS.
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Affiliation(s)
| | - Rhona McGonigal
- School of Infection & ImmunityUniversity of GlasgowGlasgowUK
| | | | | | - Denggao Yao
- School of Infection & ImmunityUniversity of GlasgowGlasgowUK
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7
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Ronchi G, Fregnan F, Muratori L, Gambarotta G, Raimondo S. Morphological Methods to Evaluate Peripheral Nerve Fiber Regeneration: A Comprehensive Review. Int J Mol Sci 2023; 24:1818. [PMID: 36768142 PMCID: PMC9915436 DOI: 10.3390/ijms24031818] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 01/06/2023] [Accepted: 01/13/2023] [Indexed: 01/18/2023] Open
Abstract
Regeneration of damaged peripheral nerves remains one of the main challenges of neurosurgery and regenerative medicine, a nerve functionality is rarely restored, especially after severe injuries. Researchers are constantly looking for innovative strategies for tackling this problem, with the development of advanced tissue-engineered nerve conduits and new pharmacological and physical interventions, with the aim of improving patients' life quality. Different evaluation methods can be used to study the effectiveness of a new treatment, including functional tests, morphological assessment of regenerated nerve fibers and biomolecular analyses of key factors necessary for good regeneration. The number and diversity of protocols and methods, as well as the availability of innovative technologies which are used to assess nerve regeneration after experimental interventions, often makes it difficult to compare results obtained in different labs. The purpose of the current review is to describe the main morphological approaches used to evaluate the degree of nerve fiber regeneration in terms of their usefulness and limitations.
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Affiliation(s)
| | | | | | | | - Stefania Raimondo
- Department of Clinical and Biological Sciences & Neuroscience Institute Cavalieri Ottolenghi (NICO), University of Torino, Orbassano, 10043 Torino, TO, Italy
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8
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Lépine S, Castellanos-Montiel MJ, Durcan TM. TDP-43 dysregulation and neuromuscular junction disruption in amyotrophic lateral sclerosis. Transl Neurodegener 2022; 11:56. [PMID: 36575535 PMCID: PMC9793560 DOI: 10.1186/s40035-022-00331-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 11/29/2022] [Indexed: 12/28/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a disease characterized by upper and lower motor neuron (MN) loss with a signature feature of cytoplasmic aggregates containing TDP-43, which are detected in nearly all patients. Mutations in the gene that encodes TDP-43 (TARBDP) are known to result in both familial and sporadic ALS. In ALS, disruption of neuromuscular junctions (NMJs) constitutes a critical event in disease pathogenesis, leading to denervation atrophy, motor impairments and disability. Morphological defects and impaired synaptic transmission at NMJs have been reported in several TDP-43 animal models and in vitro, linking TDP-43 dysregulation to the loss of NMJ integrity in ALS. Through the lens of the dying-back and dying-forward hypotheses of ALS, this review discusses the roles of TDP-43 related to synaptic function, with a focus on the potential molecular mechanisms occurring within MNs, skeletal muscles and glial cells that may contribute to NMJ disruption in ALS.
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Affiliation(s)
- Sarah Lépine
- grid.14709.3b0000 0004 1936 8649The Neuro’s Early Drug Discovery Unit (EDDU), Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, McGill University, 3801 University Street, Montreal, QC H3A 2B4 Canada ,grid.14709.3b0000 0004 1936 8649Faculty of Medicine and Health Sciences, McGill University, 3605 De La Montagne, Montreal, QC H3G 2M1 Canada
| | - Maria José Castellanos-Montiel
- grid.14709.3b0000 0004 1936 8649The Neuro’s Early Drug Discovery Unit (EDDU), Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, McGill University, 3801 University Street, Montreal, QC H3A 2B4 Canada
| | - Thomas Martin Durcan
- grid.14709.3b0000 0004 1936 8649The Neuro’s Early Drug Discovery Unit (EDDU), Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, McGill University, 3801 University Street, Montreal, QC H3A 2B4 Canada
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9
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Cristobal CD, Lee HK. Development of myelinating glia: An overview. Glia 2022; 70:2237-2259. [PMID: 35785432 PMCID: PMC9561084 DOI: 10.1002/glia.24238] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 06/24/2022] [Accepted: 06/24/2022] [Indexed: 01/07/2023]
Abstract
Myelin is essential to nervous system function, playing roles in saltatory conduction and trophic support. Oligodendrocytes (OLs) and Schwann cells (SCs) form myelin in the central and peripheral nervous systems respectively and follow different developmental paths. OLs are neural stem-cell derived and follow an intrinsic developmental program resulting in a largely irreversible differentiation state. During embryonic development, OL precursor cells (OPCs) are produced in distinct waves originating from different locations in the central nervous system, with a subset developing into myelinating OLs. OPCs remain evenly distributed throughout life, providing a population of responsive, multifunctional cells with the capacity to remyelinate after injury. SCs derive from the neural crest, are highly dependent on extrinsic signals, and have plastic differentiation states. SC precursors (SCPs) are produced in early embryonic nerve structures and differentiate into multipotent immature SCs (iSCs), which initiate radial sorting and differentiate into myelinating and non-myelinating SCs. Differentiated SCs retain the capacity to radically change phenotypes in response to external signals, including becoming repair SCs, which drive peripheral regeneration. While several transcription factors and myelin components are common between OLs and SCs, their differentiation mechanisms are highly distinct, owing to their unique lineages and their respective environments. In addition, both OLs and SCs respond to neuronal activity and regulate nervous system output in reciprocal manners, possibly through different pathways. Here, we outline their basic developmental programs, mechanisms regulating their differentiation, and recent advances in the field.
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Affiliation(s)
- Carlo D. Cristobal
- Integrative Program in Molecular and Biomedical SciencesBaylor College of MedicineHoustonTexasUSA,Jan and Dan Duncan Neurological Research InstituteTexas Children's HospitalHoustonTexasUSA
| | - Hyun Kyoung Lee
- Integrative Program in Molecular and Biomedical SciencesBaylor College of MedicineHoustonTexasUSA,Jan and Dan Duncan Neurological Research InstituteTexas Children's HospitalHoustonTexasUSA,Department of PediatricsBaylor College of MedicineHoustonTexasUSA,Department of NeuroscienceBaylor College of MedicineHoustonTexasUSA
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10
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Gorzo KA, Gordon GR. Photonics tools begin to clarify astrocyte calcium transients. NEUROPHOTONICS 2022; 9:021907. [PMID: 35211642 PMCID: PMC8857908 DOI: 10.1117/1.nph.9.2.021907] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 02/01/2022] [Indexed: 05/27/2023]
Abstract
Astrocytes integrate information from neurons and the microvasculature to coordinate brain activity and metabolism. Using a variety of calcium-dependent cellular mechanisms, these cells impact numerous aspects of neurophysiology in health and disease. Astrocyte calcium signaling is highly diverse, with complex spatiotemporal features. Here, we review astrocyte calcium dynamics and the optical imaging tools used to measure and analyze these events. We briefly cover historical calcium measurements, followed by our current understanding of how calcium transients relate to the structure of astrocytes. We then explore newer photonics tools including super-resolution techniques and genetically encoded calcium indicators targeted to specific cellular compartments and how these have been applied to astrocyte biology. Finally, we provide a brief overview of analysis software used to accurately quantify the data and ultimately aid in our interpretation of the various functions of astrocyte calcium transients.
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Affiliation(s)
- Kelsea A. Gorzo
- University of Calgary, Hotchkiss Brain Institute, Cumming School of Medicine, Calgary, Alberta, Canada
| | - Grant R. Gordon
- University of Calgary, Hotchkiss Brain Institute, Cumming School of Medicine, Calgary, Alberta, Canada
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11
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Yang R, Zhang GGZ, Kjoller K, Dillon E, Purohit HS, Taylor LS. Phase separation in surfactant-containing amorphous solid dispersions: Orthogonal analytical methods to probe the effects of surfactants on morphology and phase composition. Int J Pharm 2022; 619:121708. [PMID: 35364219 DOI: 10.1016/j.ijpharm.2022.121708] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Revised: 03/23/2022] [Accepted: 03/26/2022] [Indexed: 11/19/2022]
Abstract
Amorphous-amorphous phase separation (AAPS) is an important phase transition process for amorphous solid dispersion (ASD) performance both in terms of drug release as well as physical and chemical stability during storage. Addition of surfactants to ASD systems can impact both of these processes. One possible mechanism through which surfactants affect ASD performance is via their impact on AAPS. Unfortunately, despite their increasing usage in ASD formulations, the effect of surfactant on AAPS is still poorly understood, and there are limited analytical techniques that provide microstructural and composition information about phase separated ASDs. In this study, the impact of four surfactants (sodium dodecyl sulfate, Tween 80, Span 20 and Span 85) on water-induced phase separation in ASDs formulated with ritonavir and polyvinylpyrrolidone/vinyl acetate (PVPVA) was investigated using a variety of orthogonal analytical methods. Transparent films of ASDs with different compositions were prepared by spin coating. Fluorescence confocal microscopy in combination with an in situ humidity chamber was used to monitor the kinetics and morphology of phase separation following exposure to high relative humidity. Optical photothermal IR analysis of phase separated films enabled characterization of domain composition and surfactant distribution. Liquid-liquid phase separation concentration, zeta potential and solution nuclear magnetic resonance spectroscopy measurements enabled interpretation of interaction with and partition of surfactants into the drug-rich phase. It was found that phase separation kinetics and morphology were notably changed by the surfactants. Further, the surfactants showed different affinities for the drug-rich versus the aqueous/polymer-rich phases. The employed analytical techniques were found to be complementary in providing insight into surfactant location in phase separated systems. This study highlights the complexity of phase separation, especially in the presence of surfactants, and provides a foundation to understand the impact of AAPS on ASD performance.
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Affiliation(s)
- Ruochen Yang
- Department of Industrial and Physical Pharmacy, Purdue University, West Lafayette, IN 47907, USA
| | - Geoff G Z Zhang
- Drug Product Development, AbbVie Inc., North Chicago, IL 60064, USA
| | - Kevin Kjoller
- Photothermal Spectroscopy Corp, Santa Barbara, CA 93101, USA
| | - Eoghan Dillon
- Photothermal Spectroscopy Corp, Santa Barbara, CA 93101, USA
| | - Hitesh S Purohit
- Drug Product Development, AbbVie Inc., North Chicago, IL 60064, USA.
| | - Lynne S Taylor
- Department of Industrial and Physical Pharmacy, Purdue University, West Lafayette, IN 47907, USA.
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12
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Wei X, Nicoletti C, Puri PL. Fibro-Adipogenic Progenitors: Versatile keepers of skeletal muscle homeostasis, beyond the response to myotrauma. Semin Cell Dev Biol 2021; 119:23-31. [PMID: 34332886 PMCID: PMC8552908 DOI: 10.1016/j.semcdb.2021.07.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 07/12/2021] [Accepted: 07/17/2021] [Indexed: 10/20/2022]
Abstract
While Fibro-Adipogenic Progenitors (FAPs) have been originally identified as muscle-interstitial mesenchymal cells activated in response to muscle injury and endowed with inducible fibrogenic and adipogenic potential, subsequent studies have expanded their phenotypic and functional repertoire and revealed their contribution to skeletal muscle response to a vast range of perturbations. Here we review the emerging contribution of FAPs to skeletal muscle responses to motor neuron injuries and to systemic physiological (e.g., exercise) or pathological metabolic (e.g., diabetes) perturbations. We also provide an initial blueprint of discrete sub-clusters of FAPs that are activated by specific perturbations and discuss their role in muscle adaptation to these conditions.
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Affiliation(s)
- X Wei
- Development, Aging and Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - C Nicoletti
- Development, Aging and Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - P L Puri
- Development, Aging and Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA.
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13
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Villarroel-Campos D, Schiavo G, Sleigh JN. Dissection, in vivo imaging and analysis of the mouse epitrochleoanconeus muscle. J Anat 2021; 241:1108-1119. [PMID: 34121181 PMCID: PMC9558155 DOI: 10.1111/joa.13478] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 05/07/2021] [Accepted: 05/18/2021] [Indexed: 12/25/2022] Open
Abstract
Analysis of rodent muscles affords an opportunity to glean key insights into neuromuscular development and the detrimental impact of disease‐causing genetic mutations. Muscles of the distal leg, for instance the gastrocnemius and tibialis anterior, are commonly used in such studies with mice and rats. However, thin and flat muscles, which can be dissected, processed and imaged without major disruption to muscle fibres and nerve‐muscle contacts, are more suitable for accurate and detailed analyses of the peripheral motor nervous system. One such wholemount muscle is the predominantly fast twitch epitrochleoanconeus (ETA), which is located in the upper forelimb, innervated by the radial nerve, and contains relatively large and uniformly flat neuromuscular junctions (NMJs). To facilitate incorporation of the ETA into the experimental toolkit of the neuromuscular disease field, here, we describe a simple method for its rapid isolation (<5 min), supported by high‐resolution videos and step‐by‐step images. Furthermore, we outline how the ETA can be imaged in live, anaesthetised mice, to enable examination of dynamic cellular processes occurring at the NMJ and within intramuscular axons, including transport of organelles, such as mitochondria and signalling endosomes. Finally, we present reference data on wild‐type ETA fibre‐type composition in young adult, male C57BL6/J mice. Comparative neuroanatomical studies of different muscles in rodent models of disease can generate critical insights into pathogenesis and pathology; dissection of the wholemount ETA provides the possibility to diversify the repertoire of muscles analysed for this endeavour.
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Affiliation(s)
- David Villarroel-Campos
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Giampietro Schiavo
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, London, UK.,UK Dementia Research Institute, University College London, London, UK
| | - James N Sleigh
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, London, UK.,UK Dementia Research Institute, University College London, London, UK
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14
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Jablonka-Shariff A, Broberg C, Rios R, Snyder-Warwick AK. T-box transcription factor 21 is expressed in terminal Schwann cells at the neuromuscular junction. Muscle Nerve 2021; 64:109-115. [PMID: 33908666 DOI: 10.1002/mus.27257] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 04/23/2021] [Accepted: 04/24/2021] [Indexed: 11/10/2022]
Abstract
INTRODUCTION/AIMS Terminal Schwann cells (tSCs) are nonmyelinating Schwann cells present at the neuromuscular junction (NMJ) with multiple integral roles throughout their lifespan. There is no known gene differentiating tSCs from myelinating Schwann cells, making their isolation and investigation challenging. In this work we investigated genes expressed within tSCs. METHODS A novel dissection technique was utilized to isolate the tSC-containing NMJ band from the sternomastoid muscles of S100-GFP mice. RNA was isolated from samples containing: (a) NMJ bands (tSCs with nerve and muscle), (b) nerve, and (c) muscle, and microarray genetic expression analysis was conducted. Data were validated by quantitative real-time polymerase chain reaction (qRT-PCR) and immunofluorescent staining. To identify genes specific to tSCs compared with other NMJ components, analysis of variance and rank-order analysis were performed using the Partek Genomic Suite. RESULTS Microarray analysis of the tSC-enriched NMJ band revealed upregulation (by 4- to 12-fold) of several genes unique to the NMJ compared with muscle or nerve parts alone (P < .05). Among these genes, Tbx21 (or T-bet) was identified, which showed a 12-fold higher expression at the NMJ compared with sciatic nerve (P < .002). qRT-PCR analysis showed Tbx21 mRNA expression was over ninefold higher (P < .05) in the NMJ relative to muscle and nerve. Tbx21 protein colocalized with tSCs and was not noted in myelinating SCs from sciatic nerve. DISCUSSION We found TBX21 to be expressed in tSCs. Additional studies will be performed to determine the functional significance of TBX21 in tSCs. These studies may enhance the investigative tools available to modulate tSCs to improve motor recovery after nerve injury.
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Affiliation(s)
- Albina Jablonka-Shariff
- Division of Plastic Surgery, Department of Surgery, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - Curtis Broberg
- Division of Plastic Surgery, Department of Surgery, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - Rachel Rios
- Division of Plastic Surgery, Department of Surgery, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - Alison K Snyder-Warwick
- Division of Plastic Surgery, Department of Surgery, Washington University School of Medicine, Saint Louis, Missouri, USA
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15
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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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16
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Shen M, Tang W, Cheng Z, Zhang Q, Chen Z, Tian Y, Zhang Y, He Q, Shi H, Zhu H, Wu H, Ji Y, Ding F. A proteomic view on the differential phenotype of Schwann cells derived from mouse sensory and motor nerves. J Comp Neurol 2020; 529:1240-1254. [DOI: 10.1002/cne.25018] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 07/21/2020] [Accepted: 08/12/2020] [Indexed: 12/12/2022]
Affiliation(s)
- Mi Shen
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co‐Innovation Center of Neuroregeneration Nantong University Nantong China
- Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Research Center of Clinical Medicine, Affiliated Hospital of Nantong University Nantong China
| | - Wei Tang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co‐Innovation Center of Neuroregeneration Nantong University Nantong China
| | - Zhenghui Cheng
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co‐Innovation Center of Neuroregeneration Nantong University Nantong China
| | - Qi Zhang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co‐Innovation Center of Neuroregeneration Nantong University Nantong China
| | - Zixin Chen
- Department of Immunobiology, College of Life Science and Technology Jinan University Guangzhou China
| | - Yingchao Tian
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co‐Innovation Center of Neuroregeneration Nantong University Nantong China
| | - Yawen Zhang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co‐Innovation Center of Neuroregeneration Nantong University Nantong China
| | - Qianru He
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co‐Innovation Center of Neuroregeneration Nantong University Nantong China
| | - Haiyan Shi
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co‐Innovation Center of Neuroregeneration Nantong University Nantong China
| | - Hui Zhu
- Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Research Center of Clinical Medicine, Affiliated Hospital of Nantong University Nantong China
| | - Han Wu
- Department of General Surgery Affiliated Hospital of Nantong University Nantong China
| | - Yuhua Ji
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co‐Innovation Center of Neuroregeneration Nantong University Nantong China
- Department of Immunobiology, College of Life Science and Technology Jinan University Guangzhou China
| | - Fei Ding
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co‐Innovation Center of Neuroregeneration Nantong University Nantong China
- Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Research Center of Clinical Medicine, Affiliated Hospital of Nantong University Nantong China
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17
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Rabah Y, Rubino B, Moukarzel E, Agulhon C. Characterization of transgenic mouse lines for selectively targeting satellite glial cells and macrophages in dorsal root ganglia. PLoS One 2020; 15:e0229475. [PMID: 32915783 PMCID: PMC7485865 DOI: 10.1371/journal.pone.0229475] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Accepted: 08/12/2020] [Indexed: 02/06/2023] Open
Abstract
The importance of glial cells in the modulation of neuronal processes is now generally accepted. In particular, enormous progress in our understanding of astrocytes and microglia physiology in the central nervous system (CNS) has been made in recent years, due to the development of genetic and molecular toolkits. However, the roles of satellite glial cells (SGCs) and macrophages-the peripheral counterparts of astrocytes and microglia-remain poorly studied despite their involvement in debilitating conditions, such as pain. Here, we characterized in dorsal root ganglia (DRGs), different genetically-modified mouse lines previously used for studying astrocytes and microglia, with the goal to implement them for investigating DRG SGC and macrophage functions. Although SGCs and astrocytes share some molecular properties, most tested transgenic lines were found to not be suitable for studying selectively a large number of SGCs within DRGs. Nevertheless, we identified and validated two mouse lines: (i) a CreERT2 recombinase-based mouse line allowing transgene expression almost exclusively in SGCs and in the vast majority of SGCs, and (ii) a GFP-expressing line allowing the selective visualization of macrophages. In conclusion, among the tools available for exploring astrocyte functions, a few can be used for studying selectively a great proportion of SGCs. Thus, efforts remain to be made to characterize other available mouse lines as well as to develop, rigorously characterize and validate new molecular tools to investigate the roles of DRG SGCs, but also macrophages, in health and disease.
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Affiliation(s)
- Yasmine Rabah
- Integrative Neuroscience and Cognition Center (CNRS UMR8002), Glia-Glia & Glia-Neuron Interactions Laboratory, Faculty of Basic and Biomedical Sciences, Paris Descartes University, Paris, France
| | - Bruna Rubino
- Integrative Neuroscience and Cognition Center (CNRS UMR8002), Glia-Glia & Glia-Neuron Interactions Laboratory, Faculty of Basic and Biomedical Sciences, Paris Descartes University, Paris, France
| | - Elsie Moukarzel
- Integrative Neuroscience and Cognition Center (CNRS UMR8002), Glia-Glia & Glia-Neuron Interactions Laboratory, Faculty of Basic and Biomedical Sciences, Paris Descartes University, Paris, France
| | - Cendra Agulhon
- Integrative Neuroscience and Cognition Center (CNRS UMR8002), Glia-Glia & Glia-Neuron Interactions Laboratory, Faculty of Basic and Biomedical Sciences, Paris Descartes University, Paris, France
- * E-mail:
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18
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Min Q, Parkinson DB, Dun XP. Migrating Schwann cells direct axon regeneration within the peripheral nerve bridge. Glia 2020; 69:235-254. [PMID: 32697392 DOI: 10.1002/glia.23892] [Citation(s) in RCA: 127] [Impact Index Per Article: 31.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 07/03/2020] [Accepted: 07/08/2020] [Indexed: 12/12/2022]
Abstract
Schwann cells within the peripheral nervous system possess a remarkable regenerative potential. Current research shows that peripheral nerve-associated Schwann cells possess the capacity to promote repair of multiple tissues including peripheral nerve gap bridging, skin wound healing, digit tip repair as well as tooth regeneration. One of the key features of the specialized repair Schwann cells is that they become highly motile. They not only migrate into the area of damaged tissue and become a key component of regenerating tissue but also secrete signaling molecules to attract macrophages, support neuronal survival, promote axonal regrowth, activate local mesenchymal stem cells, and interact with other cell types. Currently, the importance of migratory Schwann cells in tissue regeneration is most evident in the case of a peripheral nerve transection injury. Following nerve transection, Schwann cells from both proximal and distal nerve stumps migrate into the nerve bridge and form Schwann cell cords to guide axon regeneration. The formation of Schwann cell cords in the nerve bridge is key to successful peripheral nerve repair following transection injury. In this review, we first examine nerve bridge formation and the behavior of Schwann cell migration in the nerve bridge, and then discuss how migrating Schwann cells direct regenerating axons into the distal nerve. We also review the current understanding of signals that could activate Schwann cell migration and signals that Schwann cells utilize to direct axon regeneration. Understanding the molecular mechanism of Schwann cell migration could potentially offer new therapeutic strategies for peripheral nerve repair.
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Affiliation(s)
- Qing Min
- School of Pharmacy, Hubei University of Science and Technology, Xianning, Hubei Province, People's Republic of China
| | - David B Parkinson
- Peninsula Medical School, Faculty of Health, Plymouth University, Plymouth, Devon, UK
| | - Xin-Peng Dun
- School of Pharmacy, Hubei University of Science and Technology, Xianning, Hubei Province, People's Republic of China
- Peninsula Medical School, Faculty of Health, Plymouth University, Plymouth, Devon, UK
- The Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, People's Republic of China
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19
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Morphological remodeling during recovery of the neuromuscular junction from terminal Schwann cell ablation in adult mice. Sci Rep 2020; 10:11132. [PMID: 32636481 PMCID: PMC7341867 DOI: 10.1038/s41598-020-67630-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 06/09/2020] [Indexed: 12/22/2022] Open
Abstract
Schwann cells (SCs) are integral to the formation and function of the peripheral nervous system (PNS). Exemplifying their importance, the loss or dysfunction of SCs is a feature of a myriad of diseases and conditions that compromise the PNS. Thus, it remains essential to understand the rules that govern the proliferation, differentiation and reconnection of Schwann cells with peripheral axons. Here, we examined the consequences of locally and acutely ablating terminal Schwann cells (tSCs) at the adult mouse neuromuscular junction (NMJ) by using mice expressing diphtheria toxin receptor (DTR) preferentially in tSCs compared to myelinating SCs followed by local application of diphtheria toxin (DTX). After DTX application, tSCs died but, importantly and contrary to expectations, their associated motor axons did not fully degenerate. Within 3 weeks, tSCs returned and reestablished coverage of the synapse with increased numbers. Furthermore, the post-synaptic muscle fibers displayed increased distinct clusters of acetylcholine receptors and axon terminals exhibited numerous terminal varicosities. The lack of degeneration of bare motor axon terminals and the morphological remodeling that occurs upon the return of tSCs to the NMJ may have wider implications for the mechanisms governing tSC occupancy of the adult NMJ and for conditions that adversely affect tSCs.
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20
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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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21
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Castro R, Taetzsch T, Vaughan SK, Godbe K, Chappell J, Settlage RE, Valdez G. Specific labeling of synaptic schwann cells reveals unique cellular and molecular features. eLife 2020; 9:e56935. [PMID: 32584256 PMCID: PMC7316509 DOI: 10.7554/elife.56935] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 06/08/2020] [Indexed: 12/14/2022] Open
Abstract
Perisynaptic Schwann cells (PSCs) are specialized, non-myelinating, synaptic glia of the neuromuscular junction (NMJ), that participate in synapse development, function, maintenance, and repair. The study of PSCs has relied on an anatomy-based approach, as the identities of cell-specific PSC molecular markers have remained elusive. This limited approach has precluded our ability to isolate and genetically manipulate PSCs in a cell specific manner. We have identified neuron-glia antigen 2 (NG2) as a unique molecular marker of S100β+ PSCs in skeletal muscle. NG2 is expressed in Schwann cells already associated with the NMJ, indicating that it is a marker of differentiated PSCs. Using a newly generated transgenic mouse in which PSCs are specifically labeled, we show that PSCs have a unique molecular signature that includes genes known to play critical roles in PSCs and synapses. These findings will serve as a springboard for revealing drivers of PSC differentiation and function.
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Affiliation(s)
- Ryan Castro
- Department of Molecular Biology, Cellular Biology, and Biochemistry, Brown UniversityProvidenceUnited States
- Center for Translational Neuroscience, Robert J. and Nancy D. Carney Institute for Brain Science and Brown Institute for Translational Science, Brown UniversityProvidenceUnited States
- Neuroscience Graduate Program, Brown UniversityProvidenceUnited States
| | - Thomas Taetzsch
- Department of Molecular Biology, Cellular Biology, and Biochemistry, Brown UniversityProvidenceUnited States
- Center for Translational Neuroscience, Robert J. and Nancy D. Carney Institute for Brain Science and Brown Institute for Translational Science, Brown UniversityProvidenceUnited States
| | - Sydney K Vaughan
- Department of Molecular Biology, Cellular Biology, and Biochemistry, Brown UniversityProvidenceUnited States
- Center for Translational Neuroscience, Robert J. and Nancy D. Carney Institute for Brain Science and Brown Institute for Translational Science, Brown UniversityProvidenceUnited States
| | - Kerilyn Godbe
- Fralin Biomedical Research Institute at Virginia Tech CarilionRoanokeUnited States
| | - John Chappell
- Fralin Biomedical Research Institute at Virginia Tech CarilionRoanokeUnited States
| | - Robert E Settlage
- Department of Advanced Research Computing, Virginia TechBlacksburgUnited States
| | - Gregorio Valdez
- Department of Molecular Biology, Cellular Biology, and Biochemistry, Brown UniversityProvidenceUnited States
- Center for Translational Neuroscience, Robert J. and Nancy D. Carney Institute for Brain Science and Brown Institute for Translational Science, Brown UniversityProvidenceUnited States
- Department of Neurology, Warren Alpert Medical School of Brown UniversityProvidenceUnited States
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22
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Cunningham ME, Meehan GR, Robinson S, Yao D, McGonigal R, Willison HJ. Perisynaptic Schwann cells phagocytose nerve terminal debris in a mouse model of Guillain-Barré syndrome. J Peripher Nerv Syst 2020; 25:143-151. [PMID: 32250537 PMCID: PMC8299349 DOI: 10.1111/jns.12373] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 02/25/2020] [Accepted: 03/30/2020] [Indexed: 12/13/2022]
Abstract
In mouse models of acute motor axonal neuropathy, anti-ganglioside antibodies (AGAbs) bind to motor axons, notably the distal nerve, and activate the complement cascade. While complement activation is well studied in this model, the role of inflammatory cells is unknown. Herein we aimed to investigate the contribution of phagocytic cells including macrophages, neutrophils and perisynaptic Schwann cells (pSCs) to distal nerve pathology. To observe this, we first created a subacute injury model of sufficient duration to allow inflammatory cell recruitment. Mice were injected intraperitoneally with an anti-GD1b monoclonal antibody that binds strongly to mouse motor nerve axons. Subsequently, mice received normal human serum as a source of complement. Dosing was titrated to allow humane survival of mice over a period of 3 days, yet still induce the characteristic neurological impairment. Behaviour and pathology were assessed in vivo using whole-body plethysmography and post-sacrifice by immunofluorescence and flow cytometry. ex vivo nerve-muscle preparations were used to investigate the acute phagocytic role of pSCs following distal nerve injury. Following complement activation at distal intramuscular nerve sites in the diaphragm macrophage localisation or numbers are not altered, nor do they shift to a pro- or anti-inflammatory phenotype. Similarly, neutrophils are not significantly recruited. Instead, ex vivo nerve-muscle preparations exposed to AGAb plus complement reveal that pSCs rapidly become phagocytic and engulf axonal debris. These data suggest that pSCs, rather than inflammatory cells, are the major cellular vehicle for axonal debris clearance following distal nerve injury, in contrast to larger nerve bundles where macrophage-mediated clearance predominates.
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Affiliation(s)
- Madeleine E. Cunningham
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life SciencesUniversity of GlasgowGlasgowUK
| | - Gavin R. Meehan
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life SciencesUniversity of GlasgowGlasgowUK
| | - Sophie Robinson
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life SciencesUniversity of GlasgowGlasgowUK
| | - Denggao Yao
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life SciencesUniversity of GlasgowGlasgowUK
| | - Rhona McGonigal
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life SciencesUniversity of GlasgowGlasgowUK
| | - Hugh J. Willison
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life SciencesUniversity of GlasgowGlasgowUK
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23
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Otsu Y, Darcq E, Pietrajtis K, Mátyás F, Schwartz E, Bessaih T, Abi Gerges S, Rousseau CV, Grand T, Dieudonné S, Paoletti P, Acsády L, Agulhon C, Kieffer BL, Diana MA. Control of aversion by glycine-gated GluN1/GluN3A NMDA receptors in the adult medial habenula. Science 2020; 366:250-254. [PMID: 31601771 DOI: 10.1126/science.aax1522] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 09/17/2019] [Indexed: 01/05/2023]
Abstract
The unconventional N-methyl-d-aspartate (NMDA) receptor subunits GluN3A and GluN3B can, when associated with the other glycine-binding subunit GluN1, generate excitatory conductances purely activated by glycine. However, functional GluN1/GluN3 receptors have not been identified in native adult tissues. We discovered that GluN1/GluN3A receptors are operational in neurons of the mouse adult medial habenula (MHb), an epithalamic area controlling aversive physiological states. In the absence of glycinergic neuronal specializations in the MHb, glial cells tuned neuronal activity via GluN1/GluN3A receptors. Reducing GluN1/GluN3A receptor levels in the MHb prevented place-aversion conditioning. Our study extends the physiological and behavioral implications of glycine by demonstrating its control of negatively valued emotional associations via excitatory glycinergic NMDA receptors.
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Affiliation(s)
- Y Otsu
- Institut de Biologie de l'École Normale Supérieure (IBENS), INSERM U1024, CNRS UMR8197, École Normale Supérieure, Université PSL, 75005 Paris, France
| | - E Darcq
- Department of Psychiatry, School of Medicine, Douglas Hospital Research Center, McGill University, Montreal, QC H4H 1R3, Canada
| | - K Pietrajtis
- Sorbonne Université, CNRS, INSERM, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS-IBPS), 75005 Paris, France
| | - F Mátyás
- Laboratory of Thalamus Research, Institute of Experimental Medicine, Hungarian Academy of Sciences, 1083 Budapest, Hungary.,Research Centre for Natural Sciences Institute of Cognitive Neuroscience and Psychology, 1117 Budapest, Hungary.,Department of Anatomy and Histology, University of Veterinary Medicine, 1078 Budapest, Hungary
| | - E Schwartz
- Sorbonne Université, CNRS, INSERM, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS-IBPS), 75005 Paris, France
| | - T Bessaih
- Sorbonne Université, CNRS, INSERM, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS-IBPS), 75005 Paris, France
| | - S Abi Gerges
- Sorbonne Université, CNRS, INSERM, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS-IBPS), 75005 Paris, France
| | - C V Rousseau
- Institut de Biologie de l'École Normale Supérieure (IBENS), INSERM U1024, CNRS UMR8197, École Normale Supérieure, Université PSL, 75005 Paris, France
| | - T Grand
- Institut de Biologie de l'École Normale Supérieure (IBENS), INSERM U1024, CNRS UMR8197, École Normale Supérieure, Université PSL, 75005 Paris, France
| | - S Dieudonné
- Institut de Biologie de l'École Normale Supérieure (IBENS), INSERM U1024, CNRS UMR8197, École Normale Supérieure, Université PSL, 75005 Paris, France
| | - P Paoletti
- Institut de Biologie de l'École Normale Supérieure (IBENS), INSERM U1024, CNRS UMR8197, École Normale Supérieure, Université PSL, 75005 Paris, France
| | - L Acsády
- Laboratory of Thalamus Research, Institute of Experimental Medicine, Hungarian Academy of Sciences, 1083 Budapest, Hungary
| | - C Agulhon
- Integrative Neuroscience and Cognition Center, CNRS UMR8002, Glia-Glia and Glia-Neuron Interactions Group, Paris Descartes University, 75006 Paris, France
| | - B L Kieffer
- Department of Psychiatry, School of Medicine, Douglas Hospital Research Center, McGill University, Montreal, QC H4H 1R3, Canada
| | - M A Diana
- Sorbonne Université, CNRS, INSERM, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS-IBPS), 75005 Paris, France.
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25
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Abstract
OBJECTIVE This review details the agents for fluorescence-guided nerve imaging in both preclinical and clinical use to identify factors important in selecting nerve-specific fluorescent agents for surgical procedures. BACKGROUND Iatrogenic nerve injury remains a significant cause of morbidity in patients undergoing surgical procedures. Current real-time identification of nerves during surgery involves neurophysiologic nerve stimulation, which has practical limitations. Intraoperative fluorescence-guided imaging provides a complimentary means of differentiating tissue types and pathology. Recent advances in fluorescence-guided nerve imaging have shown promise, but the ideal agent remains elusive. METHODS In February 2018, PubMed was searched for articles investigating peripheral nerve fluorescence. Key terms used in this search include: "intraoperative, nerve, fluorescence, peripheral nerve, visualization, near infrared, and myelin." Limits were set to exclude articles exclusively dealing with central nervous system targets or written in languages other than English. References were cross-checked for articles not otherwise identified. RESULTS Of the nonspecific agents, tracers that rely on axonal transport showed the greatest tissue specificity; however, neurovascular dyes already enjoy wide clinical use. Fluorophores specific to nerve moieties result in excellent nerve to background ratios. Although noteworthy findings on tissue specificity, toxicity, and route of administration specific to each fluorescent agent were reported, significant data objectively quantifying nerve-specific fluorescence and toxicity are lacking. CONCLUSIONS Fluorescence-based nerve enhancement has advanced rapidly over the past 10 years with potential for continued utilization and progression in translational research. An ideal agent would be easily administered perioperatively, would not cross the blood-brain barrier, and would fluoresce in the near-infrared spectrum. Agents administered systemically that target nerve-specific moieties have shown the greatest promise. Based on the heterogeneity of published studies and methods for reporting outcomes, it appears that the development of an optimal nerve imaging agent remains challenging.
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Kondor Y, Tykholaz V, Huminskyi Y. Morphology of the pathways of intracellular circulation in the brain. PAIN MEDICINE 2020. [DOI: 10.31636/pmjua.v4i4.4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The article reflects the current position of the issue of morphologies of the pathways of intercellular circulation in the brain. There are covered main, known at present time, data on the features of the exchange between the spinal fluid and intercellular fluid, the ways of elimination of the intertissued fluid of the brain through the so-called “glymphatic system”, its components: transarterial, transvenous, and transglial ways of intercellular fluid outflow from brain tissue. It also raises the question of the role of glia namely astrocytes and ependymocytes – as the main cells forming the haemato-encephalic barrier and participating in the intercellular circulation.
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Chen B, Chen Q, Parkinson DB, Dun XP. Analysis of Schwann Cell Migration and Axon Regeneration Following Nerve Injury in the Sciatic Nerve Bridge. Front Mol Neurosci 2019; 12:308. [PMID: 31920539 PMCID: PMC6914761 DOI: 10.3389/fnmol.2019.00308] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 11/29/2019] [Indexed: 12/18/2022] Open
Abstract
While it is proposed that interaction between Schwann cells and axons is key for successful nerve regeneration, the behavior of Schwann cells migrating into a nerve gap following a transection injury and how migrating Schwann cells interact with regenerating axons within the nerve bridge has not been studied in detail. In this study, we combine the use of our whole-mount sciatic nerve staining with the use of a proteolipid protein-green fluorescent protein (PLP-GFP) mouse model to mark Schwann cells and have examined the behavior of migrating Schwann cells and regenerating axons in the sciatic nerve gap following a nerve transection injury. We show here that Schwann cell migration from both nerve stumps starts later than the regrowth of axons from the proximal nerve stump. The first migrating Schwann cells are only observed 4 days following mouse sciatic nerve transection injury. Schwann cells migrating from the proximal nerve stump overtake regenerating axons on day 5 and form Schwann cell cords within the nerve bridge by 7 days post-transection injury. Regenerating axons begin to attach to migrating Schwann cells on day 6 and then follow their trajectory navigating across the nerve gap. We also observe that Schwann cell cords in the nerve bridge are not wide enough to guide all the regenerating axons across the nerve bridge, resulting in regenerating axons growing along the outside of both proximal and distal nerve stumps. From this analysis, we demonstrate that Schwann cells play a crucial role in controlling the directionality and speed of axon regeneration across the nerve gap. We also demonstrate that the use of the PLP-GFP mouse model labeling Schwann cells together with the whole sciatic nerve axon staining technique is a useful research model to study the process of peripheral nerve regeneration.
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Affiliation(s)
- Bing Chen
- Department of Neurology, The Affiliated Huai'an No.1 People's Hospital of Nanjing Medical University, Huai'an, China
| | - Quan Chen
- Department of Neurology, The Affiliated Huai'an No.1 People's Hospital of Nanjing Medical University, Huai'an, China
| | - David B Parkinson
- Faculty of Health: Medicine, Dentistry and Human Sciences, Plymouth University, Plymouth, United Kingdom
| | - Xin-Peng Dun
- Faculty of Health: Medicine, Dentistry and Human Sciences, Plymouth University, Plymouth, United Kingdom
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Tomlinson JE, Golshadi M, Donahue CJ, Dong L, Cheetham J. Evaluation of two methods to isolate Schwann cells from murine sciatic nerve. J Neurosci Methods 2019; 331:108483. [PMID: 31756398 DOI: 10.1016/j.jneumeth.2019.108483] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 10/04/2019] [Accepted: 10/27/2019] [Indexed: 12/12/2022]
Abstract
BACKGROUND Schwann cells (SC) and macrophages play key roles in the response to peripheral nerve injury (PNI). Accurate isolation of such cells is essential for further analyses that can lead to better understanding of the repair process after PNI. Separation of live SC from the injury site without culture enrichment is necessary for targeted gene expression analysis. NEW METHODS Two flow cytometric techniques are presented for rapid enrichment of live SC and macrophages from injured murine peripheral nerve without the need for culture. RESULTS SC were isolated by fluorescent activated cell sorting (FACS) using transgenic expression of eGFP in SC, or by exclusion of other cell types collected from the injury site. COMPARISON WITH EXISTING METHOD(S) Gene expression analyses of peripheral nerve repair have commonly used whole nerve lysates. Isolating SC allows more accurate understanding of their specific role in repair. SC are commonly enriched from nerve by culture, however this changes gene expression patterns and limits the utility for transcriptomic analysis. The surface marker p75-NTR has variable expression in different SC phenotypes and during the course of injury and repair. Using p75-NTR for SC isolation might enrich only a subset of SC. More stably expressed lineage markers for SC are intracellular and not suitable for sorting for gene expression. The methods used here avoid the requirement for surface marker labeling of SC. CONCLUSION Gene expression analysis of sorted cells from both methods showed successful enrichment of SC. Lineage markers such as Map1b, p75-NTR and S100b were enriched in the sorted SC population. SC sorting by eGFP expression showed improved enrichment, particularly of mature myelinating genes, although this could represent sampling of a subset of SC.
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Affiliation(s)
- Joy E Tomlinson
- Cornell University College of Veterinary Medicine, Department of Clinical Sciences, 930 Campus Road, Ithaca, NY, 14853, United States
| | - Masoud Golshadi
- Cornell University College of Veterinary Medicine, Department of Clinical Sciences, 930 Campus Road, Ithaca, NY, 14853, United States
| | - Christopher J Donahue
- Cornell University College of Veterinary Medicine, Department of Clinical Sciences, 930 Campus Road, Ithaca, NY, 14853, United States
| | - Lynn Dong
- Cornell University College of Veterinary Medicine, Department of Clinical Sciences, 930 Campus Road, Ithaca, NY, 14853, United States
| | - Jonathan Cheetham
- Cornell University College of Veterinary Medicine, Department of Clinical Sciences, 930 Campus Road, Ithaca, NY, 14853, United States.
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Morton AB, Norton CE, Jacobsen NL, Fernando CA, Cornelison DDW, Segal SS. Barium chloride injures myofibers through calcium-induced proteolysis with fragmentation of motor nerves and microvessels. Skelet Muscle 2019; 9:27. [PMID: 31694693 PMCID: PMC6833148 DOI: 10.1186/s13395-019-0213-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 09/30/2019] [Indexed: 12/15/2022] Open
Abstract
Background Local injection of BaCl2 is an established model of acute injury to study the regeneration of skeletal muscle. However, the mechanism by which BaCl2 causes muscle injury is unresolved. Because Ba2+ inhibits K+ channels, we hypothesized that BaCl2 induces myofiber depolarization leading to Ca2+ overload, proteolysis, and membrane disruption. While BaCl2 spares resident satellite cells, its effect on other tissue components integral to contractile function has not been defined. We therefore asked whether motor nerves and microvessels, which control and supply myofibers, are injured by BaCl2 treatment. Methods The intact extensor digitorum longus (EDL) muscle was isolated from male mice (aged 3–4 months) and irrigated with physiological salt solution (PSS) at 37 °C. Myofiber membrane potential (Vm) was recorded using sharp microelectrodes while intracellular calcium concentration ([Ca2+]i) was evaluated with Fura 2 dye. Isometric force production of EDL was measured in situ, proteolytic activity was quantified by calpain degradation of αII-spectrin, and membrane disruption was marked by nuclear staining with propidium iodide (PI). To test for effects on motor nerves and microvessels, tibialis anterior or gluteus maximus muscles were injected with 1.2% BaCl2 (50–75 μL) in vivo followed by immunostaining to evaluate the integrity of respective tissue elements post injury. Data were analyzed using Students t test and analysis of variance with P ≤ 0.05 considered statistically significant. Results Addition of 1.2% BaCl2 to PSS depolarized myofibers from − 79 ± 3 mV to − 17 ± 7 mV with a corresponding rise in [Ca2+]i; isometric force transiently increased from 7.4 ± 0.1 g to 11.1 ± 0.4 g. Following 1 h of BaCl2 exposure, 92 ± 3% of myonuclei stained with PI (vs. 8 ± 3% in controls) with enhanced cleavage of αII-spectrin. Eliminating Ca2+ from PSS prevented the rise in [Ca2+]i and ameliorated myonuclear staining with PI during BaCl2 exposure. Motor axons and capillary networks appeared fragmented within 24 h following injection of 1.2% BaCl2 and morphological integrity deteriorated through 72 h. Conclusions BaCl2 injures myofibers through depolarization of the sarcolemma, causing Ca2+ overload with transient contraction, leading to proteolysis and membrane rupture. Motor innervation and capillarity appear disrupted concomitant with myofiber damage, further compromising muscle integrity.
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Affiliation(s)
- Aaron B Morton
- Department of Medical Pharmacology and Physiology, University of Missouri, MA415 Medical Sciences Building, 1 Hospital Drive, Columbia, MO, 65212, USA
| | - Charles E Norton
- Department of Medical Pharmacology and Physiology, University of Missouri, MA415 Medical Sciences Building, 1 Hospital Drive, Columbia, MO, 65212, USA
| | - Nicole L Jacobsen
- Department of Medical Pharmacology and Physiology, University of Missouri, MA415 Medical Sciences Building, 1 Hospital Drive, Columbia, MO, 65212, USA
| | - Charmain A Fernando
- Department of Medical Pharmacology and Physiology, University of Missouri, MA415 Medical Sciences Building, 1 Hospital Drive, Columbia, MO, 65212, USA
| | - D D W Cornelison
- Division of Biological Sciences and Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, MO, 65201, USA
| | - Steven S Segal
- Department of Medical Pharmacology and Physiology, University of Missouri, MA415 Medical Sciences Building, 1 Hospital Drive, Columbia, MO, 65212, USA. .,Dalton Cardiovascular Research Center, Columbia, MO, 65211, USA.
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Allogenic tissue-specific decellularized scaffolds promote long-term muscle innervation and functional recovery in a surgical diaphragmatic hernia model. Acta Biomater 2019; 89:115-125. [PMID: 30851456 DOI: 10.1016/j.actbio.2019.03.007] [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: 10/23/2018] [Revised: 02/22/2019] [Accepted: 03/05/2019] [Indexed: 01/08/2023]
Abstract
Congenital diaphragmatic hernia (CDH) is a neonatal defect in which the diaphragm muscle does not develop properly, thereby raising abdominal organs into the thoracic cavity and impeding lung development and function. Large diaphragmatic defects require correction with prosthetic patches to close the malformation. This treatment leads to a consequent generation of unwelcomed mechanical stress in the repaired diaphragm and hernia recurrences, thereby resulting in high morbidity and significant mortality rates. We proposed a specific diaphragm-derived extracellular matrix (ECM) as a scaffold for the treatment of CDH. To address this strategy, we developed a new surgical CDH mouse model to test the ability of our tissue-specific patch to regenerate damaged diaphragms. Implantation of decellularized diaphragmatic ECM-derived patches demonstrated absence of rejection or hernia recurrence, in contrast to the performance of a commercially available synthetic material. Diaphragm-derived ECM was able to promote the generation of new blood vessels, boost long-term muscle regeneration, and recover host diaphragmatic function. In addition, using a GFP + Schwann cell mouse model, we identified re-innervation of implanted patches. These results demonstrated for the first time that implantation of a tissue-specific biologic scaffold is able to promote a regenerating diaphragm muscle and overcome issues commonly related to the standard use of prosthetic materials. STATEMENT OF SIGNIFICANCE: Large diaphragmatic hernia in paediatric patients require application of artificial patches to close the congenital defect. The use of a muscle-specific decellularized scaffold in substitution of currently used synthetic materials allows new blood vessel growth and nerve regeneration inside the patch, supporting new muscle tissue formation. Furthermore, the presence of a tissue-specific scaffold guaranteed long-term muscle regeneration, improving diaphragm performance to almost complete functional recovery. We believe that diaphragm-derived scaffold will be key player in future pre-clinical studies on large animal models.
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Larsson L, Degens H, Li M, Salviati L, Lee YI, Thompson W, Kirkland JL, Sandri M. Sarcopenia: Aging-Related Loss of Muscle Mass and Function. Physiol Rev 2019; 99:427-511. [PMID: 30427277 DOI: 10.1152/physrev.00061.2017] [Citation(s) in RCA: 783] [Impact Index Per Article: 156.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Sarcopenia is a loss of muscle mass and function in the elderly that reduces mobility, diminishes quality of life, and can lead to fall-related injuries, which require costly hospitalization and extended rehabilitation. This review focuses on the aging-related structural changes and mechanisms at cellular and subcellular levels underlying changes in the individual motor unit: specifically, the perikaryon of the α-motoneuron, its neuromuscular junction(s), and the muscle fibers that it innervates. Loss of muscle mass with aging, which is largely due to the progressive loss of motoneurons, is associated with reduced muscle fiber number and size. Muscle function progressively declines because motoneuron loss is not adequately compensated by reinnervation of muscle fibers by the remaining motoneurons. At the intracellular level, key factors are qualitative changes in posttranslational modifications of muscle proteins and the loss of coordinated control between contractile, mitochondrial, and sarcoplasmic reticulum protein expression. Quantitative and qualitative changes in skeletal muscle during the process of aging also have been implicated in the pathogenesis of acquired and hereditary neuromuscular disorders. In experimental models, specific intervention strategies have shown encouraging results on limiting deterioration of motor unit structure and function under conditions of impaired innervation. Translated to the clinic, if these or similar interventions, by saving muscle and improving mobility, could help alleviate sarcopenia in the elderly, there would be both great humanitarian benefits and large cost savings for health care systems.
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Affiliation(s)
- Lars Larsson
- Department of Physiology and Pharmacology, Basic and Clinical Muscle Biology Group, Karolinska Institutet , Stockholm , Sweden ; Section of Clinical Neurophysiology, Department of Clinical Neuroscience, Karolinska Institutet , Stockholm , Sweden ; Department of Biobehavioral Health, The Pennsylvania State University , University Park, Pennsylvania ; School of Healthcare Science, Metropolitan University , Manchester , United Kingdom ; Institute of Sport Science and Innovations, Lithuanian Sports University , Kaunas , Lithuania ; Clinical Genetics Unit, Department of Woman and Child Health, University of Padova , Padova , Italy ; IRP Città della Speranza, Padova , Italy ; Department of Biology, Texas A&M University , College Station, Texas ; Robert and Arlene Kogod Center on Aging, Mayo Clinic , Rochester, Minnesota ; Department of Biomedical Science, Venetian Institute of Molecular Medicine, University of Padova , Padova , Italy
| | - Hans Degens
- Department of Physiology and Pharmacology, Basic and Clinical Muscle Biology Group, Karolinska Institutet , Stockholm , Sweden ; Section of Clinical Neurophysiology, Department of Clinical Neuroscience, Karolinska Institutet , Stockholm , Sweden ; Department of Biobehavioral Health, The Pennsylvania State University , University Park, Pennsylvania ; School of Healthcare Science, Metropolitan University , Manchester , United Kingdom ; Institute of Sport Science and Innovations, Lithuanian Sports University , Kaunas , Lithuania ; Clinical Genetics Unit, Department of Woman and Child Health, University of Padova , Padova , Italy ; IRP Città della Speranza, Padova , Italy ; Department of Biology, Texas A&M University , College Station, Texas ; Robert and Arlene Kogod Center on Aging, Mayo Clinic , Rochester, Minnesota ; Department of Biomedical Science, Venetian Institute of Molecular Medicine, University of Padova , Padova , Italy
| | - Meishan Li
- Department of Physiology and Pharmacology, Basic and Clinical Muscle Biology Group, Karolinska Institutet , Stockholm , Sweden ; Section of Clinical Neurophysiology, Department of Clinical Neuroscience, Karolinska Institutet , Stockholm , Sweden ; Department of Biobehavioral Health, The Pennsylvania State University , University Park, Pennsylvania ; School of Healthcare Science, Metropolitan University , Manchester , United Kingdom ; Institute of Sport Science and Innovations, Lithuanian Sports University , Kaunas , Lithuania ; Clinical Genetics Unit, Department of Woman and Child Health, University of Padova , Padova , Italy ; IRP Città della Speranza, Padova , Italy ; Department of Biology, Texas A&M University , College Station, Texas ; Robert and Arlene Kogod Center on Aging, Mayo Clinic , Rochester, Minnesota ; Department of Biomedical Science, Venetian Institute of Molecular Medicine, University of Padova , Padova , Italy
| | - Leonardo Salviati
- Department of Physiology and Pharmacology, Basic and Clinical Muscle Biology Group, Karolinska Institutet , Stockholm , Sweden ; Section of Clinical Neurophysiology, Department of Clinical Neuroscience, Karolinska Institutet , Stockholm , Sweden ; Department of Biobehavioral Health, The Pennsylvania State University , University Park, Pennsylvania ; School of Healthcare Science, Metropolitan University , Manchester , United Kingdom ; Institute of Sport Science and Innovations, Lithuanian Sports University , Kaunas , Lithuania ; Clinical Genetics Unit, Department of Woman and Child Health, University of Padova , Padova , Italy ; IRP Città della Speranza, Padova , Italy ; Department of Biology, Texas A&M University , College Station, Texas ; Robert and Arlene Kogod Center on Aging, Mayo Clinic , Rochester, Minnesota ; Department of Biomedical Science, Venetian Institute of Molecular Medicine, University of Padova , Padova , Italy
| | - Young Il Lee
- Department of Physiology and Pharmacology, Basic and Clinical Muscle Biology Group, Karolinska Institutet , Stockholm , Sweden ; Section of Clinical Neurophysiology, Department of Clinical Neuroscience, Karolinska Institutet , Stockholm , Sweden ; Department of Biobehavioral Health, The Pennsylvania State University , University Park, Pennsylvania ; School of Healthcare Science, Metropolitan University , Manchester , United Kingdom ; Institute of Sport Science and Innovations, Lithuanian Sports University , Kaunas , Lithuania ; Clinical Genetics Unit, Department of Woman and Child Health, University of Padova , Padova , Italy ; IRP Città della Speranza, Padova , Italy ; Department of Biology, Texas A&M University , College Station, Texas ; Robert and Arlene Kogod Center on Aging, Mayo Clinic , Rochester, Minnesota ; Department of Biomedical Science, Venetian Institute of Molecular Medicine, University of Padova , Padova , Italy
| | - Wesley Thompson
- Department of Physiology and Pharmacology, Basic and Clinical Muscle Biology Group, Karolinska Institutet , Stockholm , Sweden ; Section of Clinical Neurophysiology, Department of Clinical Neuroscience, Karolinska Institutet , Stockholm , Sweden ; Department of Biobehavioral Health, The Pennsylvania State University , University Park, Pennsylvania ; School of Healthcare Science, Metropolitan University , Manchester , United Kingdom ; Institute of Sport Science and Innovations, Lithuanian Sports University , Kaunas , Lithuania ; Clinical Genetics Unit, Department of Woman and Child Health, University of Padova , Padova , Italy ; IRP Città della Speranza, Padova , Italy ; Department of Biology, Texas A&M University , College Station, Texas ; Robert and Arlene Kogod Center on Aging, Mayo Clinic , Rochester, Minnesota ; Department of Biomedical Science, Venetian Institute of Molecular Medicine, University of Padova , Padova , Italy
| | - James L Kirkland
- Department of Physiology and Pharmacology, Basic and Clinical Muscle Biology Group, Karolinska Institutet , Stockholm , Sweden ; Section of Clinical Neurophysiology, Department of Clinical Neuroscience, Karolinska Institutet , Stockholm , Sweden ; Department of Biobehavioral Health, The Pennsylvania State University , University Park, Pennsylvania ; School of Healthcare Science, Metropolitan University , Manchester , United Kingdom ; Institute of Sport Science and Innovations, Lithuanian Sports University , Kaunas , Lithuania ; Clinical Genetics Unit, Department of Woman and Child Health, University of Padova , Padova , Italy ; IRP Città della Speranza, Padova , Italy ; Department of Biology, Texas A&M University , College Station, Texas ; Robert and Arlene Kogod Center on Aging, Mayo Clinic , Rochester, Minnesota ; Department of Biomedical Science, Venetian Institute of Molecular Medicine, University of Padova , Padova , Italy
| | - Marco Sandri
- Department of Physiology and Pharmacology, Basic and Clinical Muscle Biology Group, Karolinska Institutet , Stockholm , Sweden ; Section of Clinical Neurophysiology, Department of Clinical Neuroscience, Karolinska Institutet , Stockholm , Sweden ; Department of Biobehavioral Health, The Pennsylvania State University , University Park, Pennsylvania ; School of Healthcare Science, Metropolitan University , Manchester , United Kingdom ; Institute of Sport Science and Innovations, Lithuanian Sports University , Kaunas , Lithuania ; Clinical Genetics Unit, Department of Woman and Child Health, University of Padova , Padova , Italy ; IRP Città della Speranza, Padova , Italy ; Department of Biology, Texas A&M University , College Station, Texas ; Robert and Arlene Kogod Center on Aging, Mayo Clinic , Rochester, Minnesota ; Department of Biomedical Science, Venetian Institute of Molecular Medicine, University of Padova , Padova , Italy
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Kang H, Tian L, Thompson WJ. Schwann cell guidance of nerve growth between synaptic sites explains changes in the pattern of muscle innervation and remodeling of synaptic sites following peripheral nerve injuries. J Comp Neurol 2019; 527:1388-1400. [PMID: 30620049 DOI: 10.1002/cne.24625] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 12/17/2018] [Accepted: 12/20/2018] [Indexed: 01/14/2023]
Abstract
Terminal Schwann cells (SCs) are nonmyelinating glia that are a prominent component of the neuromuscular junction (NMJ) where motor neurons form synapses onto muscle fibers. These cells play important roles not only in development and maintenance of the neuromuscular synapse but also restoring synaptic function after nerve damage. In response to muscle denervation, terminal SCs undergo dramatic changes in their gene expression patterns as well as in their morphology, such as extending elaborate processes into inter-junctional space. These SC processes serve as a path to guide axon terminal sprouts from nearby innervated junctions, promoting rapid reinnervation of denervated fibers. We studied the role of terminal SCs in synapse reformation by using two different fluorescent proteins to simultaneously label motor axons and SCs; we examined these junctions repeatedly in living animals using a fluorescence microscope. Here, we show that alterations in the patterns of muscle innervation following recovery from nerve injury can be explained by SC guidance of regenerating axons. In turn, this guidance leads to remodeling of the NMJ itself.
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Affiliation(s)
- Hyuno Kang
- Section of Molecular Cell and Developmental Biology, The University of Texas at Austin, Austin, Texas.,Gwangju Center, Korea Basic Science Institute, Gwangju, South Korea
| | - Le Tian
- Section of Molecular Cell and Developmental Biology, The University of Texas at Austin, Austin, Texas
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Piantanida AP, Acosta LE, Brocardo L, Capurro C, Greer CA, Rela L. Selective Cre-mediated gene deletion identifies connexin 43 as the main connexin channel supporting olfactory ensheathing cell networks. J Comp Neurol 2019; 527:1278-1289. [PMID: 30628061 DOI: 10.1002/cne.24628] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 12/27/2018] [Accepted: 01/02/2019] [Indexed: 02/07/2023]
Abstract
Many functions of glial cells depend on the formation of selective glial networks mediated by gap junctions formed by members of the connexin family. Olfactory ensheathing cells (OECs) are specialized glia associated with olfactory sensory neuron axons. Like other glia, they form selective networks, however, the connexins that support OEC connectivity in vivo have not been identified. We used an in vivo mouse model to selectively delete candidate connexin genes with temporal control from OECs and address the physiological consequences. Using this model, we effectively abolished the expression of connexin 43 (Cx43) in OECs in both juvenile and adult mice. Cx43-deleted OECs exhibited features consistent with the loss of gap junctions including reduced membrane conductance, largely reduced sensitivity to the gap junction blocker meclofenamic acid and loss of dye coupling. This indicates that Cx43, a typically astrocytic connexin, is the main connexin forming functional channels in OECs. Despite these changes in functional properties, the deletion of Cx43 deletion did not alter the density of OECs. The strategy used here may prove useful to delete other candidate genes to better understand the functional roles of OECs in vivo.
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Affiliation(s)
- Ana Paula Piantanida
- CONICET, Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO), Neurociencia de Sistemas, Buenos Aires, Argentina.,Universidad de Buenos Aires, Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO), Neurociencia de Sistemas, Buenos Aires, Argentina
| | - Luis Ernesto Acosta
- CONICET, Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO), Neurociencia de Sistemas, Buenos Aires, Argentina.,Universidad de Buenos Aires, Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO), Neurociencia de Sistemas, Buenos Aires, Argentina
| | - Lucila Brocardo
- CONICET, Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO), Neurociencia de Sistemas, Buenos Aires, Argentina.,Universidad de Buenos Aires, Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO), Neurociencia de Sistemas, Buenos Aires, Argentina
| | - Claudia Capurro
- CONICET, Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO), Neurociencia de Sistemas, Buenos Aires, Argentina.,Universidad de Buenos Aires, Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO), Neurociencia de Sistemas, Buenos Aires, Argentina
| | - Charles A Greer
- Department of Neuroscience, Yale University School of Medicine, New Haven, Connecticut.,Department of Neurosurgery, Yale University School of Medicine, New Haven, Connecticut
| | - Lorena Rela
- CONICET, Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO), Neurociencia de Sistemas, Buenos Aires, Argentina.,Universidad de Buenos Aires, Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO), Neurociencia de Sistemas, Buenos Aires, Argentina
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Guttenplan KA, Liddelow SA. Astrocytes and microglia: Models and tools. J Exp Med 2018; 216:71-83. [PMID: 30541903 PMCID: PMC6314517 DOI: 10.1084/jem.20180200] [Citation(s) in RCA: 93] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Revised: 08/16/2018] [Accepted: 11/26/2018] [Indexed: 01/05/2023] Open
Abstract
An amazing array of tools both old and new are available to investigate the function of astrocytes and microglia. Guttenplan and Liddelow discuss tools available to study the physiology and pathophysiology of these cells both in vivo and in culture systems. Glial cells serve as fundamental regulators of the central nervous system in development, homeostasis, and disease. Discoveries into the function of these cells have fueled excitement in glial research, with enthusiastic researchers addressing fundamental questions about glial biology and producing new scientific tools for the community. Here, we outline the pros and cons of in vivo and in vitro techniques to study astrocytes and microglia with the goal of helping researchers quickly identify the best approach for a given research question in the context of glial biology. It is truly a great time to be a glial biologist.
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Affiliation(s)
| | - Shane A Liddelow
- Neuroscience Institute, NYU Langone Medical Center, New York, NY.,Department of Neuroscience and Physiology, NYU Langone Medical Center, New York, NY.,Department of Pharmacology and Therapeutics, The University of Melbourne, Melbourne, Australia
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35
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Haddix SG, Lee YI, Kornegay JN, Thompson WJ. Cycles of myofiber degeneration and regeneration lead to remodeling of the neuromuscular junction in two mammalian models of Duchenne muscular dystrophy. PLoS One 2018; 13:e0205926. [PMID: 30379896 PMCID: PMC6209224 DOI: 10.1371/journal.pone.0205926] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 10/03/2018] [Indexed: 12/02/2022] Open
Abstract
Mice lacking the sarcolemmal protein dystrophin, designated mdx, have been widely used as a model of Duchenne muscular dystrophy. Dystrophic mdx mice as they mature develop notable morphological abnormalities to their neuromuscular junctions, the peripheral cholinergic synapses responsible for activating muscle fibers. Most obviously the acetylcholine receptor aggregates are fragmented into small non-continuous, islands. This contrasts with wild type mice whose acetylcholine receptor aggregates are continuous and pretzel-shaped in appearance. We show here that these abnormalities in mdx mice are also present in a canine model of Duchenne muscular dystrophy and provide additional evidence to support the hypothesis that NMJ remodeling occurs due to myofiber degeneration and regeneration. Using a method to investigate synaptic AChR replacement, we show that neuromuscular junction remodeling in mdx animals is caused by muscle fiber degeneration and regeneration at the synaptic site and is mimicked by deliberate myofiber injury in wild type mice. Importantly, the innervating motor axon plays a crucial role in directing the remodeling of the neuromuscular junction in dystrophy, as has been recorded in aging and deliberate muscle fiber injury in wild type mice. The remodeling occurs repetitively through the life of the animal and the changes in junctions become greater with age.
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Affiliation(s)
- Seth G. Haddix
- Texas A&M Institute for Neuroscience, Texas A&M University, College Station, Texas, United States of America
- * E-mail:
| | - Young il Lee
- Texas A&M Institute for Neuroscience, Texas A&M University, College Station, Texas, United States of America
- Department of Biology, Texas A&M University, College Station, Texas, United States of America
| | - Joe N. Kornegay
- Texas A&M Institute for Neuroscience, Texas A&M University, College Station, Texas, United States of America
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas, United States of America
| | - Wesley J. Thompson
- Texas A&M Institute for Neuroscience, Texas A&M University, College Station, Texas, United States of America
- Department of Biology, Texas A&M University, College Station, Texas, United States of America
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Martineau É, Di Polo A, Vande Velde C, Robitaille R. Dynamic neuromuscular remodeling precedes motor-unit loss in a mouse model of ALS. eLife 2018; 7:41973. [PMID: 30320556 PMCID: PMC6234026 DOI: 10.7554/elife.41973] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 10/14/2018] [Indexed: 12/13/2022] Open
Abstract
Despite being an early event in ALS, it remains unclear whether the denervation of neuromuscular junctions (NMJ) is simply the first manifestation of a globally degenerating motor neuron. Using in vivo imaging of single axons and their NMJs over a three-month period, we identify that single motor-units are dismantled asynchronously in SOD1G37R mice. We reveal that weeks prior to complete axonal degeneration, the dismantling of axonal branches is accompanied by contemporaneous new axonal sprouting resulting in synapse formation onto nearby NMJs. Denervation events tend to propagate from the first lost NMJ, consistent with a contribution of neuromuscular factors extrinsic to motor neurons, with distal branches being more susceptible. These results show that NMJ denervation in ALS is a complex and dynamic process of continuous denervation and new innervation rather than a manifestation of sudden global motor neuron degeneration. Amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig’s disease, is a fatal neurodegenerative disorder. It occurs when the neurons that control muscles – the motoneurons – disconnect from their target muscles and die. This causes the muscles to weaken and waste away. More and more muscles become affected over time until eventually the muscles that control breathing also become paralyzed. Most patients die within two to five years of diagnosis. Motoneurons consist of a cell body plus a cable-like structure called the axon. The cell body of each motoneuron sits within the spinal cord, and the axon extends out of the spinal cord to the motoneuron’s target muscle. Within the muscle the axon divides into branches, each of which connects with multiple muscle fibers. The breakdown of these connections, known as neuromuscular junctions, is one of the first signs of ALS. Does a motoneuron lose all of its connections with muscle fibers at once, or do the connections break down a few at a time? This distinction is important as it will help to identify the events that lead to muscle paralysis in ALS. To find out, Martineau et al. studied mice that had two genetic mutations: one that causes ALS and another that produces fluorescent molecules in some motoneurons. This allowed the branches of the motoneurons to be tracked over time with a fluorescence microscope. Martineau et al. found that individual neurons lose their connections to muscle fibers gradually. Moreover, motoneurons grow new branches and form new connections even while losing their old ones. This dual process of pruning and budding lasts for several weeks, until eventually the motoneuron dies. Developing drugs to stabilize neuromuscular junctions during the period when motoneurons gradually disconnect from muscles could be a promising avenue to explore to improve the quality of life of ALS patients. One advantage of this treatment strategy is that neuromuscular junctions in muscles are easier to access than motoneurons inside the spinal cord. To identify potential drugs, future studies will need to focus on the proteins and signals that cause the neuromuscular junctions to break down.
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Affiliation(s)
- Éric Martineau
- Département de neurosciences, Université de Montréal, Québec, Canada.,Groupe de recherche sur le système nerveux central, Université de Montréal, Québec, Canada
| | - Adriana Di Polo
- Département de neurosciences, Université de Montréal, Québec, Canada.,Centre de recherche du Centre Hospitalier de l'Université de Montréal, Québec, Canada
| | - Christine Vande Velde
- Département de neurosciences, Université de Montréal, Québec, Canada.,Centre de recherche du Centre Hospitalier de l'Université de Montréal, Québec, Canada
| | - Richard Robitaille
- Département de neurosciences, Université de Montréal, Québec, Canada.,Groupe de recherche sur le système nerveux central, Université de Montréal, Québec, Canada
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Abstract
Astrocytes are neural cells of ectodermal, neuroepithelial origin that provide for homeostasis and defense of the central nervous system (CNS). Astrocytes are highly heterogeneous in morphological appearance; they express a multitude of receptors, channels, and membrane transporters. This complement underlies their remarkable adaptive plasticity that defines the functional maintenance of the CNS in development and aging. Astrocytes are tightly integrated into neural networks and act within the context of neural tissue; astrocytes control homeostasis of the CNS at all levels of organization from molecular to the whole organ.
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Affiliation(s)
- Alexei Verkhratsky
- The University of Manchester , Manchester , United Kingdom ; Achúcarro Basque Center for Neuroscience, IKERBASQUE, Basque Foundation for Science , Bilbao , Spain ; Department of Neuroscience, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain ; Center for Basic and Translational Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark ; and Center for Translational Neuromedicine, University of Rochester Medical Center , Rochester, New York
| | - Maiken Nedergaard
- The University of Manchester , Manchester , United Kingdom ; Achúcarro Basque Center for Neuroscience, IKERBASQUE, Basque Foundation for Science , Bilbao , Spain ; Department of Neuroscience, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain ; Center for Basic and Translational Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark ; and Center for Translational Neuromedicine, University of Rochester Medical Center , Rochester, New York
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38
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Verkhratsky A, Nedergaard M. Physiology of Astroglia. Physiol Rev 2018; 98:239-389. [PMID: 29351512 PMCID: PMC6050349 DOI: 10.1152/physrev.00042.2016] [Citation(s) in RCA: 952] [Impact Index Per Article: 158.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 03/22/2017] [Accepted: 04/27/2017] [Indexed: 02/07/2023] Open
Abstract
Astrocytes are neural cells of ectodermal, neuroepithelial origin that provide for homeostasis and defense of the central nervous system (CNS). Astrocytes are highly heterogeneous in morphological appearance; they express a multitude of receptors, channels, and membrane transporters. This complement underlies their remarkable adaptive plasticity that defines the functional maintenance of the CNS in development and aging. Astrocytes are tightly integrated into neural networks and act within the context of neural tissue; astrocytes control homeostasis of the CNS at all levels of organization from molecular to the whole organ.
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Affiliation(s)
- Alexei Verkhratsky
- The University of Manchester , Manchester , United Kingdom ; Achúcarro Basque Center for Neuroscience, IKERBASQUE, Basque Foundation for Science , Bilbao , Spain ; Department of Neuroscience, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain ; Center for Basic and Translational Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark ; and Center for Translational Neuromedicine, University of Rochester Medical Center , Rochester, New York
| | - Maiken Nedergaard
- The University of Manchester , Manchester , United Kingdom ; Achúcarro Basque Center for Neuroscience, IKERBASQUE, Basque Foundation for Science , Bilbao , Spain ; Department of Neuroscience, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain ; Center for Basic and Translational Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark ; and Center for Translational Neuromedicine, University of Rochester Medical Center , Rochester, New York
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39
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Hodges JL, Yu X, Gilmore A, Bennett H, Tjia M, Perna JF, Chen CC, Li X, Lu J, Zuo Y. Astrocytic Contributions to Synaptic and Learning Abnormalities in a Mouse Model of Fragile X Syndrome. Biol Psychiatry 2017; 82:139-149. [PMID: 27865451 PMCID: PMC5348290 DOI: 10.1016/j.biopsych.2016.08.036] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 08/12/2016] [Accepted: 08/30/2016] [Indexed: 11/17/2022]
Abstract
BACKGROUND Fragile X syndrome (FXS) is the most common type of mental retardation attributable to a single-gene mutation. It is caused by FMR1 gene silencing and the consequent loss of its protein product, fragile X mental retardation protein. Fmr1 global knockout (KO) mice recapitulate many behavioral and synaptic phenotypes associated with FXS. Abundant evidence suggests that astrocytes are important contributors to neurological diseases. This study investigates astrocytic contributions to the progression of synaptic abnormalities and learning impairments associated with FXS. METHODS Taking advantage of the Cre-lox system, we generated and characterized mice in which fragile X mental retardation protein is selectively deleted or exclusively expressed in astrocytes. We performed in vivo two-photon imaging to track spine dynamics/morphology along dendrites of neurons in the motor cortex and examined associated behavioral defects. RESULTS We found that adult astrocyte-specific Fmr1 KO mice displayed increased spine density in the motor cortex and impaired motor-skill learning. The learning defect coincided with a lack of enhanced spine dynamics in the motor cortex that normally occurs in response to motor skill acquisition. Although spine density was normal at 1 month of age in astrocyte-specific Fmr1 KO mice, new spines formed at an elevated rate. Furthermore, fragile X mental retardation protein expression in only astrocytes was insufficient to rescue most spine or behavioral defects. CONCLUSIONS Our work suggests a joint astrocytic-neuronal contribution to FXS pathogenesis and reveals that heightened spine formation during adolescence precedes the overabundance of spines and behavioral defects found in adult Fmr1 KO mice.
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Affiliation(s)
- Jennifer L. Hodges
- Department of Molecular, Cell and Developmental Biology, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Xinzhu Yu
- Department of Molecular, Cell and Developmental Biology, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Anthony Gilmore
- Department of Molecular, Cell and Developmental Biology, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Hannah Bennett
- Department of Molecular, Cell and Developmental Biology, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Michelle Tjia
- Department of Molecular, Cell and Developmental Biology, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - James F. Perna
- Department of Molecular, Cell and Developmental Biology, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Chia-Chien Chen
- Department of Molecular, Cell and Developmental Biology, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Xiang Li
- The Brain Cognition and Brain Disease Institute, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences (CAS), Shenzhen 518055, China
| | - Ju Lu
- Department of Molecular, Cell and Developmental Biology, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Yi Zuo
- Department of Molecular, Cell and Developmental Biology, University of California Santa Cruz, Santa Cruz, CA 95064, USA
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40
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Batiuk MY, de Vin F, Duqué SI, Li C, Saito T, Saido T, Fiers M, Belgard TG, Holt MG. An immunoaffinity-based method for isolating ultrapure adult astrocytes based on ATP1B2 targeting by the ACSA-2 antibody. J Biol Chem 2017; 292:8874-8891. [PMID: 28373281 DOI: 10.1074/jbc.m116.765313] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 03/10/2017] [Indexed: 12/21/2022] Open
Abstract
Astrocytes are a major cell type in the mammalian CNS. Astrocytes are now known to play a number of essential roles in processes including synapse formation and function, as well as blood-brain barrier formation and control of cerebral blood flow. However, our understanding of the molecular mechanisms underlying astrocyte development and function is still rudimentary. This lack of knowledge is at least partly due to the lack of tools currently available for astrocyte biology. ACSA-2 is a commercially available antibody originally developed for the isolation of astrocytes from young postnatal mouse brain, using magnetic cell-sorting methods, but its utility in isolating cells from adult tissue has not yet been published. Using a modified protocol, we now show that this tool can also be used to isolate ultrapure astrocytes from the adult brain. Furthermore, using a variety of techniques (including single-cell sequencing, overexpression and knockdown assays, immunoblotting, and immunohistochemistry), we identify the ACSA-2 epitope for the first time as ATP1B2 and characterize its distribution in the CNS. Finally, we show that ATP1B2 is stably expressed in multiple models of CNS injury and disease. Hence, we show that the ACSA-2 antibody possesses the potential to be an extremely valuable tool for astrocyte research, allowing the purification and characterization of astrocytes (potentially including injury and disease models) without the need for any specialized and expensive equipment. In fact, our results suggest that ACSA-2 should be a first-choice method for astrocyte isolation and characterization.
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Affiliation(s)
- Mykhailo Y Batiuk
- From the Laboratory of Glia Biology, VIB-KU Leuven Center for Brain and Disease Research.,the Laboratory of Glia Biology, KU Leuven Department of Neuroscience, and
| | - Filip de Vin
- From the Laboratory of Glia Biology, VIB-KU Leuven Center for Brain and Disease Research.,the Laboratory of Glia Biology, KU Leuven Department of Neuroscience, and
| | - Sandra I Duqué
- From the Laboratory of Glia Biology, VIB-KU Leuven Center for Brain and Disease Research.,the Laboratory of Glia Biology, KU Leuven Department of Neuroscience, and
| | - Chen Li
- From the Laboratory of Glia Biology, VIB-KU Leuven Center for Brain and Disease Research.,the Laboratory of Glia Biology, KU Leuven Department of Neuroscience, and
| | - Takashi Saito
- the Laboratory for Proteolytic Neuroscience, RIKEN Brain Science Institute, Wako-shi, Saitama 351-0106, Japan, and
| | - Takaomi Saido
- the Laboratory for Proteolytic Neuroscience, RIKEN Brain Science Institute, Wako-shi, Saitama 351-0106, Japan, and
| | - Mark Fiers
- the VIB-KU Leuven Center for Brain and Disease Research, KU Leuven, Herestraat 49, B-3000 Leuven, Belgium
| | - T Grant Belgard
- the Medical Research Council Functional Genomics Unit, Department of Physiology, Anatomy, and Genetics, University of Oxford, South Parks Road, Oxford OX1 3PT, United Kingdom
| | - Matthew G Holt
- From the Laboratory of Glia Biology, VIB-KU Leuven Center for Brain and Disease Research, .,the Laboratory of Glia Biology, KU Leuven Department of Neuroscience, and
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41
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Cunningham ME, McGonigal R, Meehan GR, Barrie JA, Yao D, Halstead SK, Willison HJ. Anti-ganglioside antibodies are removed from circulation in mice by neuronal endocytosis. Brain 2016; 139:1657-65. [PMID: 27017187 PMCID: PMC4892750 DOI: 10.1093/brain/aww056] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 01/14/2016] [Accepted: 01/28/2016] [Indexed: 12/26/2022] Open
Abstract
SEE VAN DOORN AND JACOBS DOI101093/BRAIN/AWW078 FOR A SCIENTIFIC COMMENTARY ON THIS ARTICLE : In axonal forms of Guillain-Barré syndrome, anti-ganglioside antibodies bind gangliosides on nerve surfaces, thereby causing injury through complement activation and immune cell recruitment. Why some nerve regions are more vulnerable than others is unknown. One reason may be that neuronal membranes with high endocytic activity, including nerve terminals involved in neurotransmitter recycling, are able to endocytose anti-ganglioside antibodies from the cell surface so rapidly that antibody-mediated injury is attenuated. Herein we investigated whether endocytic clearance of anti-ganglioside antibodies by nerve terminals might also be of sufficient magnitude to deplete circulating antibody levels. Remarkably, systemically delivered anti-ganglioside antibody in mice was so avidly cleared from the circulation by endocytosis at ganglioside-expressing plasma membranes that it was rapidly rendered undetectable in serum. A major component of the clearance occurred at motor nerve terminals of neuromuscular junctions, from where anti-ganglioside antibody was retrogradely transported to the motor neuron cell body in the spinal cord, recycled to the plasma membrane, and secreted into the surrounding spinal cord. Uptake at the neuromuscular junction represents a major unexpected pathway by which pathogenic anti-ganglioside antibodies, and potentially other ganglioside binding proteins, are cleared from the systemic circulation and also covertly delivered to the central nervous system.
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Affiliation(s)
- Madeleine E Cunningham
- Neuroimmunology Group, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, UK
| | - Rhona McGonigal
- Neuroimmunology Group, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, UK
| | - Gavin R Meehan
- Neuroimmunology Group, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, UK
| | - Jennifer A Barrie
- Neuroimmunology Group, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, UK
| | - Denggao Yao
- Neuroimmunology Group, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, UK
| | - Susan K Halstead
- Neuroimmunology Group, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, UK
| | - Hugh J Willison
- Neuroimmunology Group, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, UK
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42
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Pietronigro E, Zenaro E, Constantin G. Imaging of Leukocyte Trafficking in Alzheimer's Disease. Front Immunol 2016; 7:33. [PMID: 26913031 PMCID: PMC4753285 DOI: 10.3389/fimmu.2016.00033] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 01/23/2016] [Indexed: 12/17/2022] Open
Abstract
Alzheimer's disease (AD) is the most common neurodegenerative disorder and is characterized by a progressive decline of cognitive functions. The neuropathological features of AD include amyloid beta (Aβ) deposition, intracellular neurofibrillary tangles derived from the cytoskeletal hyperphosphorylated tau protein, amyloid angiopathy, the loss of synapses, and neuronal degeneration. In the last decade, inflammation has emerged as a key feature of AD, but most studies have focused on the role of microglia-driven neuroinflammation mechanisms. A dysfunctional blood-brain barrier has also been implicated in the pathogenesis of AD, and several studies have demonstrated that the vascular deposition of Aβ induces the expression of adhesion molecules and alters the expression of tight junction proteins, potentially facilitating the transmigration of circulating leukocytes. Two-photon laser scanning microscopy (TPLSM) has become an indispensable tool to dissect the molecular mechanisms controlling leukocyte trafficking in the central nervous system (CNS). Recent TPLSM studies have shown that vascular deposition of Aβ in the CNS promotes intraluminal neutrophil adhesion and crawling on the brain endothelium and also that neutrophils extravasate in the parenchyma preferentially in areas with Aβ deposits. These studies have also highlighted a role for LFA-1 integrin in neutrophil accumulation in the CNS of AD-like disease models, revealing that LFA-1 inhibition reduces the corresponding cognitive deficit and AD neuropathology. In this article, we consider how current imaging techniques can help to unravel new inflammation mechanisms in the pathogenesis of AD and identify novel therapeutic strategies to treat the disease by interfering with leukocyte trafficking mechanisms.
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Affiliation(s)
- Enrica Pietronigro
- Section of General Pathology, Department of Medicine, University of Verona , Verona , Italy
| | - Elena Zenaro
- Section of General Pathology, Department of Medicine, University of Verona , Verona , Italy
| | - Gabriela Constantin
- Section of General Pathology, Department of Medicine, University of Verona , Verona , Italy
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43
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Neuregulin1 displayed on motor axons regulates terminal Schwann cell-mediated synapse elimination at developing neuromuscular junctions. Proc Natl Acad Sci U S A 2016; 113:E479-87. [PMID: 26755586 DOI: 10.1073/pnas.1519156113] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Synaptic connections in the nervous system are rearranged during development and in adulthood as a feature of growth, plasticity, aging, and disease. Glia are implicated as active participants in these changes. Here we investigated a signal that controls the participation of peripheral glia, the terminal Schwann cells (SCs), at the neuromuscular junction (NMJ) in mice. Transgenic manipulation of the levels of membrane-tethered neuregulin1 (NRG1-III), a potent activator of SCs normally presented on motor axons, alters the rate of loss of motor inputs at NMJs during developmental synapse elimination. In addition, NMJs of adult transgenic mice that expressed excess axonal NRG1-III exhibited continued remodeling, in contrast to the more stable morphologies of controls. In fact, synaptic SCs of these adult mice with NRG1-III overexpression exhibited behaviors evident in wild type neonates during synapse elimination, including an affinity for the postsynaptic myofiber surface and phagocytosis of nerve terminals. Given that levels of NRG1-III expression normally peak during the period of synapse elimination, our findings identify axon-tethered NRG1 as a molecular determinant for SC-driven neuromuscular synaptic plasticity.
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44
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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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45
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Stark DA, Coffey NJ, Pancoast HR, Arnold LL, Walker JPD, Vallée J, Robitaille R, Garcia ML, Cornelison DDW. Ephrin-A3 promotes and maintains slow muscle fiber identity during postnatal development and reinnervation. J Cell Biol 2015; 211:1077-91. [PMID: 26644518 PMCID: PMC4674275 DOI: 10.1083/jcb.201502036] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Accepted: 10/22/2015] [Indexed: 11/28/2022] Open
Abstract
Each adult mammalian skeletal muscle has a unique complement of fast and slow myofibers, reflecting patterns established during development and reinforced via their innervation by fast and slow motor neurons. Existing data support a model of postnatal "matching" whereby predetermined myofiber type identity promotes pruning of inappropriate motor axons, but no molecular mechanism has yet been identified. We present evidence that fiber type-specific repulsive interactions inhibit innervation of slow myofibers by fast motor axons during both postnatal maturation of the neuromuscular junction and myofiber reinnervation after injury. The repulsive guidance ligand ephrin-A3 is expressed only on slow myofibers, whereas its candidate receptor, EphA8, localizes exclusively to fast motor endplates. Adult mice lacking ephrin-A3 have dramatically fewer slow myofibers in fast and mixed muscles, and misexpression of ephrin-A3 on fast myofibers followed by denervation/reinnervation promotes their respecification to a slow phenotype. We therefore conclude that Eph/ephrin interactions guide the fiber type specificity of neuromuscular interactions during development and adult life.
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Affiliation(s)
- Danny A Stark
- Division of Biological Sciences, University of Missouri, Columbia, MO 65211 Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, MO 65211
| | - Nathan J Coffey
- Division of Biological Sciences, University of Missouri, Columbia, MO 65211
| | - Hannah R Pancoast
- Division of Biological Sciences, University of Missouri, Columbia, MO 65211
| | - Laura L Arnold
- Division of Biological Sciences, University of Missouri, Columbia, MO 65211 Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, MO 65211
| | - J Peyton D Walker
- Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, MO 65211
| | - Joanne Vallée
- Département de Neurosciences, Université de Montréal, Montréal, Québec H3C 3J7, Canada
| | - Richard Robitaille
- Département de Neurosciences, Université de Montréal, Montréal, Québec H3C 3J7, Canada Groupe de Recherche sur le Système Nerveux Central, Université de Montréal, Montréal, Québec H3C 3J7, Canada
| | - Michael L Garcia
- Division of Biological Sciences, University of Missouri, Columbia, MO 65211 Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, MO 65211
| | - D D W Cornelison
- Division of Biological Sciences, University of Missouri, Columbia, MO 65211 Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, MO 65211
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46
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Ko CP, Robitaille R. Perisynaptic Schwann Cells at the Neuromuscular Synapse: Adaptable, Multitasking Glial Cells. Cold Spring Harb Perspect Biol 2015; 7:a020503. [PMID: 26430218 PMCID: PMC4588062 DOI: 10.1101/cshperspect.a020503] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The neuromuscular junction (NMJ) is engineered to be a highly reliable synapse to carry the control of the motor commands of the nervous system over the muscles. Its development, organization, and synaptic properties are highly structured and regulated to support such reliability and efficacy. Yet, the NMJ is also highly plastic, able to react to injury and adapt to changes. This balance between structural stability and synaptic efficacy on one hand and structural plasticity and repair on another hand is made possible by the intricate regulation of perisynaptic Schwann cells, glial cells at this synapse. They regulate both the efficacy and structural plasticity of the NMJ in a dynamic, bidirectional manner owing to their ability to decode synaptic transmission and by their interactions via trophic-related factors.
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Affiliation(s)
- Chien-Ping Ko
- Section of Neurobiology, Department of Biological Sciences, University of Southern California, Los Angeles, California 90089-2520
| | - Richard Robitaille
- Département de Neurosciences, Université de Montréal, Montréal, Québec H3C 3J7, Canada Groupe de Recherche sur le Système Nerveux Central, Université de Montréal, Montréal, Québec H3C 3J7, Canada
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47
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Monk KR, Feltri ML, Taveggia C. New insights on Schwann cell development. Glia 2015; 63:1376-93. [PMID: 25921593 PMCID: PMC4470834 DOI: 10.1002/glia.22852] [Citation(s) in RCA: 179] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Accepted: 04/13/2015] [Indexed: 12/11/2022]
Abstract
In the peripheral nervous system, Schwann cells are glial cells that are in intimate contact with axons throughout development. Schwann cells generate the insulating myelin sheath and provide vital trophic support to the neurons that they ensheathe. Schwann cell precursors arise from neural crest progenitor cells, and a highly ordered developmental sequence controls the progression of these cells to become mature myelinating or nonmyelinating Schwann cells. Here, we discuss both seminal discoveries and recent advances in our understanding of the molecular mechanisms that drive Schwann cell development and myelination with a focus on cell-cell and cell-matrix signaling events.
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Affiliation(s)
- Kelly R Monk
- Department of Developmental Biology, Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, Missouri
| | - M Laura Feltri
- Department of Biochemistry and Neurology, Hunter James Kelly Research Institute, University at Buffalo, State University of New York, Buffalo, New York
| | - Carla Taveggia
- Division of Neuroscience and INSPE, San Raffaele Scientific Institute, Milan, Italy
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48
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Gao Q, Fan Y, Mu LY, Ma L, Song ZQ, Zhang YN. S100B and ADMA in cerebral small vessel disease and cognitive dysfunction. J Neurol Sci 2015; 354:27-32. [DOI: 10.1016/j.jns.2015.04.031] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2014] [Revised: 04/06/2015] [Accepted: 04/21/2015] [Indexed: 12/26/2022]
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49
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Chew LJ, DeBoy CA, Senatorov VV. Finding degrees of separation: experimental approaches for astroglial and oligodendroglial cell isolation and genetic targeting. J Neurosci Methods 2014; 236:125-47. [PMID: 25169049 PMCID: PMC4171043 DOI: 10.1016/j.jneumeth.2014.08.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Revised: 08/15/2014] [Accepted: 08/18/2014] [Indexed: 12/20/2022]
Abstract
The study of CNS glial cell function requires experimental methods to detect, purify, and manipulate each cell population with fidelity and specificity. With the identification and cloning of cell- and stage-specific markers, glial cell analysis techniques have grown beyond physical methods of tissue dissociation and cell culture, and become highly specific with immunoselection of cell cultures in vitro and genetic targeting in vivo. The unique plasticity of glial cells offers the potential for cell replacement therapies in neurological disease that utilize neural cells derived from transplanted neural stem and progenitor cells. In this mini-review, we outline general physical and genetic approaches for macroglial cell generation. We summarize cell culture methods to obtain astrocytes and oligodendrocytes and their precursors, from developing and adult tissue, as well as approaches to obtain human neural progenitor cells through the establishment of stem cells. We discuss popular targeting rodent strains designed for cell-specific detection, selection and manipulation of neuroglial cell progenitors and their committed progeny. Based on shared markers between astrocytes and stem cells, we discuss genetically modified mouse strains with overlapping expression, and highlight SOX-expressing strains available for targeting of stem and progenitor cell populations. We also include recently established mouse strains for detection, and tag-assisted RNA and miRNA analysis. This discussion aims to provide a brief overview of the rapidly expanding collection of experimental approaches and genetic resources for the isolation and targeting of macroglial cells, their sources, progeny and gene products to facilitate our understanding of their properties and potential application in pathology.
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Affiliation(s)
- Li-Jin Chew
- Center for Neuroscience Research, Children's Research Institute, Children's National Medical Center, Washington, DC, United States.
| | - Cynthia A DeBoy
- Biology Department, Trinity Washington University, Washington, DC, United States
| | - Vladimir V Senatorov
- Helen Wills Neuroscience Institute, University of California, Berkeley, CA, United States
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Benner C, van der Meulen T, Cacéres E, Tigyi K, Donaldson CJ, Huising MO. The transcriptional landscape of mouse beta cells compared to human beta cells reveals notable species differences in long non-coding RNA and protein-coding gene expression. BMC Genomics 2014; 15:620. [PMID: 25051960 PMCID: PMC4124169 DOI: 10.1186/1471-2164-15-620] [Citation(s) in RCA: 209] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Accepted: 07/10/2014] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Insulin producing beta cell and glucagon producing alpha cells are colocalized in pancreatic islets in an arrangement that facilitates the coordinated release of the two principal hormones that regulate glucose homeostasis and prevent both hypoglycemia and diabetes. However, this intricate organization has also complicated the determination of the cellular source(s) of the expression of genes that are detected in the islet. This reflects a significant gap in our understanding of mouse islet physiology, which reduces the effectiveness by which mice model human islet disease. RESULTS To overcome this challenge, we generated a bitransgenic reporter mouse that faithfully labels all beta and alpha cells in mouse islets to enable FACS-based purification and the generation of comprehensive transcriptomes of both populations. This facilitates systematic comparison across thousands of genes between the two major endocrine cell types of the islets of Langerhans whose principal hormones are of cardinal importance for glucose homeostasis. Our data leveraged against similar data for human beta cells reveal a core common beta cell transcriptome of 9900+ genes. Against the backdrop of overall similar beta cell transcriptomes, we describe marked differences in the repertoire of receptors and long non-coding RNAs between mouse and human beta cells. CONCLUSIONS The comprehensive mouse alpha and beta cell transcriptomes complemented by the comparison of the global (dis)similarities between mouse and human beta cells represent invaluable resources to boost the accuracy by which rodent models offer guidance in finding cures for human diabetes.
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Affiliation(s)
- Christopher Benner
- />Razzavi Newman Integrated Genomics and Bioinformatics Core, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037 USA
| | - Talitha van der Meulen
- />Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037 USA
| | - Elena Cacéres
- />Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037 USA
| | - Kristof Tigyi
- />Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037 USA
| | - Cynthia J Donaldson
- />Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037 USA
| | - Mark O Huising
- />Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037 USA
- />Department of Neurobiology, Physiology & Behavior, University of California, One Shields Avenue, 180 Briggs Hall, Davis, CA 95616 USA
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