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Sadhu RK, Hernandez-Padilla C, Eisenbach YE, Penič S, Zhang L, Vishwasrao HD, Behkam B, Konstantopoulos K, Shroff H, Iglič A, Peles E, Nain AS, Gov NS. Experimental and theoretical model for the origin of coiling of cellular protrusions around fibers. Nat Commun 2023; 14:5612. [PMID: 37699891 PMCID: PMC10497540 DOI: 10.1038/s41467-023-41273-y] [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: 08/26/2022] [Accepted: 08/29/2023] [Indexed: 09/14/2023] Open
Abstract
Protrusions at the leading-edge of a cell play an important role in sensing the extracellular cues during cellular spreading and motility. Recent studies provided indications that these protrusions wrap (coil) around the extracellular fibers. However, the physics of this coiling process, and the mechanisms that drive it, are not well understood. We present a combined theoretical and experimental study of the coiling of cellular protrusions on fibers of different geometry. Our theoretical model describes membrane protrusions that are produced by curved membrane proteins that recruit the protrusive forces of actin polymerization, and identifies the role of bending and adhesion energies in orienting the leading-edges of the protrusions along the azimuthal (coiling) direction. Our model predicts that the cell's leading-edge coils on fibers with circular cross-section (above some critical radius), but the coiling ceases for flattened fibers of highly elliptical cross-section. These predictions are verified by 3D visualization and quantitation of coiling on suspended fibers using Dual-View light-sheet microscopy (diSPIM). Overall, we provide a theoretical framework, supported by experiments, which explains the physical origin of the coiling phenomenon.
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Affiliation(s)
- Raj Kumar Sadhu
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, 7610001, Israel.
- Institut Curie, PSL Research University, CNRS, UMR 168, Paris, France.
| | | | - Yael Eshed Eisenbach
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Samo Penič
- Laboratory of Physics, Faculty of Electrical Engineering, University of Ljubljana, Ljubljana, Slovenia
| | - Lixia Zhang
- Advanced Imaging and Microscopy Resource, National Institutes of Health, Bethesda, MD, USA
| | - Harshad D Vishwasrao
- Advanced Imaging and Microscopy Resource, National Institutes of Health, Bethesda, MD, USA
| | - Bahareh Behkam
- Department of Mechanical Engineering, Virginia Tech, Blacksburg, VA, 24061, USA
| | | | - Hari Shroff
- Advanced Imaging and Microscopy Resource, National Institutes of Health, Bethesda, MD, USA
- Laboratory of High Resolution Optical Imaging, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, USA
| | - Aleš Iglič
- Laboratory of Physics, Faculty of Electrical Engineering, University of Ljubljana, Ljubljana, Slovenia
| | - Elior Peles
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Amrinder S Nain
- Department of Mechanical Engineering, Virginia Tech, Blacksburg, VA, 24061, USA.
| | - Nir S Gov
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, 7610001, Israel.
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Appeltshauser L, Linke J, Heil HS, Karus C, Schenk J, Hemmen K, Sommer C, Doppler K, Heinze KG. Super-resolution imaging pinpoints the periodic ultrastructure at the human node of Ranvier and its disruption in patients with polyneuropathy. Neurobiol Dis 2023; 182:106139. [PMID: 37146836 DOI: 10.1016/j.nbd.2023.106139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 04/13/2023] [Accepted: 04/25/2023] [Indexed: 05/07/2023] Open
Abstract
The node of Ranvier is the key element in saltatory conduction along myelinated axons, but its specific protein organization remains elusive in the human species. To shed light on nanoscale anatomy of the human node of Ranvier in health and disease, we assessed human nerve biopsies of patients with polyneuropathy by super-resolution fluorescence microscopy. We applied direct stochastic optical reconstruction microscopy (dSTORM) and supported our data by high-content confocal imaging combined with deep learning-based analysis. As a result, we revealed a ~ 190 nm periodic protein arrangement of cytoskeletal proteins and axoglial cell adhesion molecules in human peripheral nerves. In patients with polyneuropathy, periodic distances increased at the paranodal region of the node of Ranvier, both at the axonal cytoskeleton and at the axoglial junction. In-depth image analysis revealed a partial loss of proteins of the axoglial complex (Caspr-1, neurofascin-155) in combination with detachment from the cytoskeletal anchor protein ß2-spectrin. High content analysis showed that such paranodal disorganization occurred especially in acute and severe axonal neuropathy with ongoing Wallerian degeneration and related cytoskeletal damage. We provide nanoscale and protein-specific evidence for the prominent, but vulnerable role of the node of Ranvier for axonal integrity. Furthermore, we show that super-resolution imaging can identify, quantify and map elongated periodic protein distances and protein interaction in histopathological tissue samples. We thus introduce a promising tool for further translational applications of super resolution microscopy.
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Affiliation(s)
| | - Janis Linke
- Department of Neurology, University Hospital Würzburg, Würzburg, Germany; Rudolf Virchow Center, Center for Integrative and Translational Bioimaging, University of Würzburg, Würzburg, Germany
| | - Hannah S Heil
- Rudolf Virchow Center, Center for Integrative and Translational Bioimaging, University of Würzburg, Würzburg, Germany; Optical Cell Biology, Instituto Gulbenkian de Ciência, Oeiras, Portugal
| | - Christine Karus
- Rudolf Virchow Center, Center for Integrative and Translational Bioimaging, University of Würzburg, Würzburg, Germany
| | - Joachim Schenk
- Rudolf Virchow Center, Center for Integrative and Translational Bioimaging, University of Würzburg, Würzburg, Germany
| | - Katherina Hemmen
- Department of Neurology, University Hospital Würzburg, Würzburg, Germany
| | - Claudia Sommer
- Department of Neurology, University Hospital Würzburg, Würzburg, Germany
| | - Kathrin Doppler
- Department of Neurology, University Hospital Würzburg, Würzburg, Germany.
| | - Katrin G Heinze
- Rudolf Virchow Center, Center for Integrative and Translational Bioimaging, University of Würzburg, Würzburg, Germany.
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3
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Kang M, Yao Y. Laminin regulates oligodendrocyte development and myelination. Glia 2021; 70:414-429. [PMID: 34773273 DOI: 10.1002/glia.24117] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 10/26/2021] [Accepted: 10/29/2021] [Indexed: 11/08/2022]
Abstract
Oligodendrocytes are the cells that myelinate axons and provide trophic support to neurons in the CNS. Their dysfunction has been associated with a group of disorders known as demyelinating diseases, such as multiple sclerosis. Oligodendrocytes are derived from oligodendrocyte precursor cells, which differentiate into premyelinating oligodendrocytes and eventually mature oligodendrocytes. The development and function of oligodendrocytes are tightly regulated by a variety of molecules, including laminin, a major protein of the extracellular matrix. Accumulating evidence suggests that laminin actively regulates every aspect of oligodendrocyte biology, including survival, migration, proliferation, differentiation, and myelination. How can laminin exert such diverse functions in oligodendrocytes? It is speculated that the distinct laminin isoforms, laminin receptors, and/or key signaling molecules expressed in oligodendrocytes at different developmental stages are the reasons. Understanding molecular targets and signaling pathways unique to each aspect of oligodendrocyte biology will enable more accurate manipulation of oligodendrocyte development and function, which may have implications in the therapies of demyelinating diseases. Here in this review, we first introduce oligodendrocyte biology, followed by the expression of laminin and laminin receptors in oligodendrocytes and other CNS cells. Next, the functions of laminin in oligodendrocyte biology, including survival, migration, proliferation, differentiation, and myelination, are discussed in detail. Last, key questions and challenges in the field are discussed. By providing a comprehensive review on laminin's roles in OL lineage cells, we hope to stimulate novel hypotheses and encourage new research in the field.
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Affiliation(s)
- Minkyung Kang
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
| | - Yao Yao
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
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4
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Molecular organization and function of vertebrate septate-like junctions. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183211. [PMID: 32032590 DOI: 10.1016/j.bbamem.2020.183211] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 01/22/2020] [Accepted: 01/26/2020] [Indexed: 12/21/2022]
Abstract
Septate-like junctions display characteristic ladder-like ultrastructure reminiscent of the invertebrate epithelial septate junctions and are present at the paranodes of myelinated axons. The paranodal junctions where the myelin loops attach to the axon at the borders of the node of Ranvier provide both a paracellular barrier to ion diffusion and a lateral fence along the axonal membrane. The septate-like junctions constrain the proper distribution of nodal Na+ channels and juxtaparanodal K+ channels, which are required for the safe propagation of the nerve influx and rapid saltatory conduction. The paranodal cell adhesion molecules have been identified as target antigens in peripheral demyelinating autoimmune diseases and the pathogenic mechanisms described. This review aims at presenting the recent knowledge on the molecular and structural organization of septate-like junctions, their formation and stabilization during development, and how they are involved in demyelinating diseases.
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Stadelmann C, Timmler S, Barrantes-Freer A, Simons M. Myelin in the Central Nervous System: Structure, Function, and Pathology. Physiol Rev 2019; 99:1381-1431. [PMID: 31066630 DOI: 10.1152/physrev.00031.2018] [Citation(s) in RCA: 292] [Impact Index Per Article: 58.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Oligodendrocytes generate multiple layers of myelin membrane around axons of the central nervous system to enable fast and efficient nerve conduction. Until recently, saltatory nerve conduction was considered the only purpose of myelin, but it is now clear that myelin has more functions. In fact, myelinating oligodendrocytes are embedded in a vast network of interconnected glial and neuronal cells, and increasing evidence supports an active role of oligodendrocytes within this assembly, for example, by providing metabolic support to neurons, by regulating ion and water homeostasis, and by adapting to activity-dependent neuronal signals. The molecular complexity governing these interactions requires an in-depth molecular understanding of how oligodendrocytes and axons interact and how they generate, maintain, and remodel their myelin sheaths. This review deals with the biology of myelin, the expanded relationship of myelin with its underlying axons and the neighboring cells, and its disturbances in various diseases such as multiple sclerosis, acute disseminated encephalomyelitis, and neuromyelitis optica spectrum disorders. Furthermore, we will highlight how specific interactions between astrocytes, oligodendrocytes, and microglia contribute to demyelination in hereditary white matter pathologies.
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Affiliation(s)
- Christine Stadelmann
- Institute of Neuropathology, University Medical Center Göttingen , Göttingen , Germany ; Institute of Neuronal Cell Biology, Technical University Munich , Munich , Germany ; German Center for Neurodegenerative Diseases (DZNE), Munich , Germany ; Department of Neuropathology, University Medical Center Leipzig , Leipzig , Germany ; Munich Cluster of Systems Neurology (SyNergy), Munich , Germany ; and Max Planck Institute of Experimental Medicine, Göttingen , Germany
| | - Sebastian Timmler
- Institute of Neuropathology, University Medical Center Göttingen , Göttingen , Germany ; Institute of Neuronal Cell Biology, Technical University Munich , Munich , Germany ; German Center for Neurodegenerative Diseases (DZNE), Munich , Germany ; Department of Neuropathology, University Medical Center Leipzig , Leipzig , Germany ; Munich Cluster of Systems Neurology (SyNergy), Munich , Germany ; and Max Planck Institute of Experimental Medicine, Göttingen , Germany
| | - Alonso Barrantes-Freer
- Institute of Neuropathology, University Medical Center Göttingen , Göttingen , Germany ; Institute of Neuronal Cell Biology, Technical University Munich , Munich , Germany ; German Center for Neurodegenerative Diseases (DZNE), Munich , Germany ; Department of Neuropathology, University Medical Center Leipzig , Leipzig , Germany ; Munich Cluster of Systems Neurology (SyNergy), Munich , Germany ; and Max Planck Institute of Experimental Medicine, Göttingen , Germany
| | - Mikael Simons
- Institute of Neuropathology, University Medical Center Göttingen , Göttingen , Germany ; Institute of Neuronal Cell Biology, Technical University Munich , Munich , Germany ; German Center for Neurodegenerative Diseases (DZNE), Munich , Germany ; Department of Neuropathology, University Medical Center Leipzig , Leipzig , Germany ; Munich Cluster of Systems Neurology (SyNergy), Munich , Germany ; and Max Planck Institute of Experimental Medicine, Göttingen , Germany
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Elazar N, Vainshtein A, Rechav K, Tsoory M, Eshed-Eisenbach Y, Peles E. Coordinated internodal and paranodal adhesion controls accurate myelination by oligodendrocytes. J Cell Biol 2019; 218:2887-2895. [PMID: 31451613 PMCID: PMC6719437 DOI: 10.1083/jcb.201906099] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2019] [Revised: 07/10/2019] [Accepted: 07/11/2019] [Indexed: 01/09/2023] Open
Abstract
Elazar et al. show that reduced axoglial adhesion at both the paranodal junction and the internodes results in the formation of multimyelinated axons. Their findings demonstrate that accurate ensheathment by oligodendrocytes depends on the coordinated action of these different adhesion systems. Oligodendrocyte–axon contact is mediated by several cell adhesion molecules (CAMs) that are positioned at distinct sites along the myelin unit, yet their role during myelination remains unclear. Cadm4 and its axonal receptors, Cadm2 and Cadm3, as well as myelin-associated glycoprotein (MAG), are enriched at the internodes below the compact myelin, whereas NF155, which binds the axonal Caspr/contactin complex, is located at the paranodal junction that is formed between the axon and the terminal loops of the myelin sheath. Here we report that Cadm4-, MAG-, and Caspr-mediated adhesion cooperate during myelin membrane ensheathment. Genetic deletion of either Cadm4 and MAG or Cadm4 and Caspr resulted in the formation of multimyelinated axons due to overgrowth of the myelin away from the axon and the forming paranodal junction. Consequently, these mice displayed paranodal loops either above or underneath compact myelin. Our results demonstrate that accurate placement of the myelin sheath by oligodendrocytes requires the coordinated action of internodal and paranodal CAMs.
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Affiliation(s)
- Nimrod Elazar
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Anya Vainshtein
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Katya Rechav
- Electron Microscopy Unit, Weizmann Institute of Science, Rehovot, Israel
| | - Michael Tsoory
- Department of Veterinary Resources, Weizmann Institute of Science, Rehovot, Israel
| | - Yael Eshed-Eisenbach
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Elior Peles
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
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7
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Duncan GJ, Manesh SB, Hilton BJ, Assinck P, Plemel JR, Tetzlaff W. The fate and function of oligodendrocyte progenitor cells after traumatic spinal cord injury. Glia 2019; 68:227-245. [PMID: 31433109 DOI: 10.1002/glia.23706] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Revised: 07/24/2019] [Accepted: 08/01/2019] [Indexed: 12/27/2022]
Abstract
Oligodendrocyte progenitor cells (OPCs) are the most proliferative and dispersed population of progenitor cells in the adult central nervous system, which allows these cells to rapidly respond to damage. Oligodendrocytes and myelin are lost after traumatic spinal cord injury (SCI), compromising efficient conduction and, potentially, the long-term health of axons. In response, OPCs proliferate and then differentiate into new oligodendrocytes and Schwann cells to remyelinate axons. This culminates in highly efficient remyelination following experimental SCI in which nearly all intact demyelinated axons are remyelinated in rodent models. However, myelin regeneration comprises only one role of OPCs following SCI. OPCs contribute to scar formation after SCI and restrict the regeneration of injured axons. Moreover, OPCs alter their gene expression following demyelination, express cytokines and perpetuate the immune response. Here, we review the functional contribution of myelin regeneration and other recently uncovered roles of OPCs and their progeny to repair following SCI.
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Affiliation(s)
- Greg J Duncan
- Department of Neurology, Jungers Center for Neurosciences Research, Oregon Health and Science University, Portland, Oregon
| | - Sohrab B Manesh
- Graduate Program in Neuroscience, International Collaboration on Repair Discoveries (ICORD), University of British Columbia (UBC), Vancouver, British Columbia, Canada
| | - Brett J Hilton
- Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE), Bonn, Germany
| | - Peggy Assinck
- MRC Centre for Regenerative Medicine, University of Edinburgh, Edinburgh, UK
| | - Jason R Plemel
- Department of Medicine, Division of Neurology, Neuroscience and Mental Health Institute, University of Alberta, Calgary, Alberta, Canada
| | - Wolfram Tetzlaff
- Graduate Program in Neuroscience, International Collaboration on Repair Discoveries (ICORD), University of British Columbia (UBC), Vancouver, British Columbia, Canada.,Departments of Zoology and Surgery, University of British Columbia, Vancouver, British Columbia, Canada
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8
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Kim JY, Yoon JY, Sugiura Y, Lee SK, Park JD, Song GJ, Yang HJ. Dendropanax morbiferus leaf extract facilitates oligodendrocyte development. ROYAL SOCIETY OPEN SCIENCE 2019; 6:190266. [PMID: 31312492 PMCID: PMC6599778 DOI: 10.1098/rsos.190266] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 06/04/2019] [Indexed: 06/10/2023]
Abstract
Treatment of multiple sclerosis is effective when anti-inflammatory, neuroprotective and regenerative strategies are combined. Dendropanax morbiferus (DM) has anti-inflammatory, anti-oxidative properties, which may be beneficial for multiple sclerosis. However, there have been no reports on the effects of DM on myelination, which is critical for regenerative processes. To know whether DM benefits myelination, we checked differentiation and myelination of oligodendrocytes (OLs) in various primary culture systems treated with DM leaf EtOH extracts or control. DM extracts increased the OL membrane size in the mixed glial and pure OL precursor cell (OPC) cultures and changed OL-lineage gene expression patterns in the OPC cultures. Western blot analysis of DM-treated OPC cultures showed upregulation of MBP and phosphorylation of ERK1/2. In myelinating cocultures, DM extracts enhanced OL differentiation, followed by increased axonal contacts and myelin gene upregulations such as Myrf, CNP and PLP. Phytochemical analysis by LC-MS/MS identified multiple components from DM extracts, containing bioactive molecules such as quercetin, cannabidiol, etc. Our results suggest DM extracts enhance OL differentiation, followed by an increase in membrane size and axonal contacts, thereby indicating enhanced myelination. In addition, we found that DM extracts contain multiple bioactive components, warranting further studies in relation to finding effective components for enhancing myelination.
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Affiliation(s)
- Ji-Young Kim
- Department of Anesthesiology and Pain Medicine, Yonsei University College of Medicine, Seoul 120-749, Republic of Korea
| | - Ju-Young Yoon
- Department of Integrative Biosciences, University of Brain Education, Cheonan 31228, Republic of Korea
| | - Yuki Sugiura
- Department of Biochemistry and Integrative Medical Biology, School of Medicine, Keio University, Tokyo 160-8582, Japan
| | - Soo-Kyoung Lee
- Department of Health Science and Daily Sports, Global Cyber University, Cheonan 31228, Republic of Korea
| | - Jae-Don Park
- Cheju Halla University, Jeju 63092, Republic of Korea
| | - Gyun-Jee Song
- Department of Medical Science, International St Mary's Hospital, Catholic Kwandong University, Gangneung, Republic of Korea
| | - Hyun-Jeong Yang
- Department of Integrative Biosciences, University of Brain Education, Cheonan 31228, Republic of Korea
- Korea Institute of Brain Science, Seoul, Republic of Korea
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Guo YE, Suo N, Cui X, Yuan Q, Xie X. Vitamin C promotes oligodendrocytes generation and remyelination. Glia 2018; 66:1302-1316. [PMID: 29423921 PMCID: PMC6001564 DOI: 10.1002/glia.23306] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Revised: 01/22/2018] [Accepted: 01/29/2018] [Indexed: 12/19/2022]
Abstract
Oligodendrocyte‐formed myelin sheaths play important roles in the neuronal functions in the central nervous system. In demyelinating diseases, such as Multiple Sclerosis, the myelin sheaths are damaged and the remyelinating process is somehow hindered. Restoration of the myelin sheaths requires the differentiation of the oligodendrocyte precursor cells (OPCs) into mature oligodendrocytes (OLs). To discover small molecule compounds that might promote the OPC to OL differentiation, a high‐throughput screening system is established and L‐ascorbyl‐2‐phosphate (As‐2P), a stable form of Vitamin C (Vc), is found to greatly enhance the OPC to OL differentiation. As‐2P promotes gradual expression of OL lineage markers, including O4, CNPase and MBP, in a dose‐ and time‐dependent manner. It also facilitates the formation of myelin sheaths in OPC‐neuron co‐culture. As‐2P also promotes the repair of the myelin sheaths in vivo and provides significant therapeutic effect in a cuprizone‐mediated demyelination animal model. Interestingly, As‐2P's function in promoting OPC differentiation is not related to its antioxidant activity. And an intracellular rather than an extracellular mechanism might be involved. Considering the safe use of Vc as a dietary supplement for many years, it might also be used as an alternative medicine for CNS demyelinating diseases.
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Affiliation(s)
- Yu-E Guo
- CAS Key Laboratory of Receptor Research, the National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.,University of Chinese Academy of Sciences, Graduate School, No. 19A Yuquan Road, Beijing, 100049, China
| | - Na Suo
- CAS Key Laboratory of Receptor Research, the National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.,University of Chinese Academy of Sciences, Graduate School, No. 19A Yuquan Road, Beijing, 100049, China
| | - Xue Cui
- Shanghai Key Laboratory of Signaling and Disease Research, Laboratory of Receptor-based Bio-medicine, School of Life Sciences and Technology, Tongji University, Shanghai, 200092, China
| | - Qianting Yuan
- CAS Key Laboratory of Receptor Research, the National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Xin Xie
- CAS Key Laboratory of Receptor Research, the National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.,Shanghai Key Laboratory of Signaling and Disease Research, Laboratory of Receptor-based Bio-medicine, School of Life Sciences and Technology, Tongji University, Shanghai, 200092, China.,State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
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Roth AD, Núñez MT. Oligodendrocytes: Functioning in a Delicate Balance Between High Metabolic Requirements and Oxidative Damage. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 949:167-181. [PMID: 27714689 DOI: 10.1007/978-3-319-40764-7_8] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The study of the metabolic interactions between myelinating glia and the axons they ensheath has blossomed into an area of research much akin to the elucidation of the role of astrocytes in tripartite synapses (Tsacopoulos and Magistretti in J Neurosci 16:877-885, 1996). Still, unlike astrocytes, rich in cytochrome-P450 and other anti-oxidative defense mechanisms (Minn et al. in Brain Res Brain Res Rev 16:65-82, 1991; Wilson in Can J Physiol Pharmacol. 75:1149-1163, 1997), oligodendrocytes can be easily damaged and are particularly sensitive to both hypoxia and oxidative stress, especially during their terminal differentiation phase and while generating myelin sheaths. In the present review, we will focus in the metabolic complexity of oligodendrocytes, particularly during the processes of differentiation and myelin deposition, and with a specific emphasis in the context of oxidative stress and the intricacies of the iron metabolism of the most iron-loaded cells of the central nervous system (CNS).
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Affiliation(s)
- Alejandro D Roth
- Department of Biology, Faculty of Science, University of Chile, Santiago, Chile.
| | - Marco T Núñez
- Department of Biology, Faculty of Science, University of Chile, Santiago, Chile
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11
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Snaidero N, Simons M. The logistics of myelin biogenesis in the central nervous system. Glia 2017; 65:1021-1031. [DOI: 10.1002/glia.23116] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 12/06/2016] [Accepted: 12/12/2016] [Indexed: 01/28/2023]
Affiliation(s)
- Nicolas Snaidero
- Institute of Neuronal Cell Biology, Technical University Munich; Munich 80805 Germany
| | - Mikael Simons
- Institute of Neuronal Cell Biology, Technical University Munich; Munich 80805 Germany
- German Center for Neurodegenerative Disease (DZNE); Munich 6250 Germany
- Cellular Neuroscience; Max Planck Institute of Experimental Medicine; Göttingen 37075 Germany
- Munich Cluster for Systems Neurology (SyNergy); Munich 81377 Germany
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12
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Zou Y, Zhang WF, Liu HY, Li X, Zhang X, Ma XF, Sun Y, Jiang SY, Ma QH, Xu DE. Structure and function of the contactin-associated protein family in myelinated axons and their relationship with nerve diseases. Neural Regen Res 2017; 12:1551-1558. [PMID: 29090003 PMCID: PMC5649478 DOI: 10.4103/1673-5374.215268] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The contactin-associated protein (Caspr) family participates in nerve excitation and conduction, and neurotransmitter release in myelinated axons. We analyzed the structures and functions of the Caspr family–CNTNAP1 (Caspr1), CNTNAP2 (Caspr2), CNTNAP3 (Caspr3), CNTNAP4 (Caspr4) and CNTNAP5 (Caspr5), Caspr1–5 is not only involved in the formation of myelinated axons, but also participates in maintaining the stability of adjacent connections. Caspr1 participates in the formation, differentiation, and proliferation of neurons and astrocytes, and in motor control and cognitive function. We also analyzed the relationship between the Caspr family and neurodegenerative diseases, multiple sclerosis, and autoimmune encephalitis. However, the effects of Caspr on disease course and prognosis remain poorly understood. The effects of Caspr on disease diagnosis and treatment need further investigation.
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Affiliation(s)
- Yan Zou
- Department of Neurology, The Second People's Hospital of Wuxi, Wuxi, Jiangsu Province, China
| | - Wei-Feng Zhang
- Department of Neurology, The Second People's Hospital of Wuxi, Wuxi, Jiangsu Province, China
| | - Hai-Ying Liu
- Department of Neurology, The Second People's Hospital of Wuxi, Wuxi, Jiangsu Province, China
| | - Xia Li
- Department of Neurology, The Second People's Hospital of Wuxi, Wuxi, Jiangsu Province, China
| | - Xing Zhang
- Department of Neurology, The Second People's Hospital of Wuxi, Wuxi, Jiangsu Province, China
| | - Xiao-Fang Ma
- Department of Neurology, The Second People's Hospital of Wuxi, Wuxi, Jiangsu Province, China
| | - Yang Sun
- Department of Neurology, The Second People's Hospital of Wuxi, Wuxi, Jiangsu Province, China
| | - Shi-Yi Jiang
- Department of Neurology, The Second People's Hospital of Wuxi, Wuxi, Jiangsu Province, China
| | - Quan-Hong Ma
- Department of Neurology, The Second People's Hospital of Wuxi, Wuxi, Jiangsu Province, China
| | - De-En Xu
- Department of Neurology, The Second People's Hospital of Wuxi, Wuxi, Jiangsu Province, China
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Redmond SA, Mei F, Eshed-Eisenbach Y, Osso LA, Leshkowitz D, Shen YAA, Kay JN, Aurrand-Lions M, Lyons DA, Peles E, Chan JR. Somatodendritic Expression of JAM2 Inhibits Oligodendrocyte Myelination. Neuron 2016; 91:824-836. [PMID: 27499083 DOI: 10.1016/j.neuron.2016.07.021] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Revised: 06/08/2016] [Accepted: 07/01/2016] [Indexed: 02/05/2023]
Abstract
Myelination occurs selectively around neuronal axons to increase the efficiency and velocity of action potentials. While oligodendrocytes are capable of myelinating permissive structures in the absence of molecular cues, structurally permissive neuronal somata and dendrites remain unmyelinated. Utilizing a purified spinal cord neuron-oligodendrocyte myelinating co-culture system, we demonstrate that disruption of dynamic neuron-oligodendrocyte signaling by chemical cross-linking results in aberrant myelination of the somatodendritic compartment of neurons. We hypothesize that an inhibitory somatodendritic cue is necessary to prevent non-axonal myelination. Using next-generation sequencing and candidate profiling, we identify neuronal junction adhesion molecule 2 (JAM2) as an inhibitory myelin-guidance molecule. Taken together, our results demonstrate that the somatodendritic compartment directly inhibits myelination and suggest a model in which broadly indiscriminate myelination is tailored by inhibitory signaling to meet local myelination requirements.
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Affiliation(s)
- Stephanie A Redmond
- Department of Neurology and Program in Neuroscience, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Feng Mei
- Department of Neurology and Program in Neuroscience, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Yael Eshed-Eisenbach
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Lindsay A Osso
- Department of Neurology and Program in Neuroscience, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Dena Leshkowitz
- Bioinformatics Unit, Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Yun-An A Shen
- Department of Neurology and Program in Neuroscience, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Jeremy N Kay
- Departments of Neurobiology and Ophthalmology, Duke University School of Medicine, Durham, NC 27703, USA
| | - Michel Aurrand-Lions
- Centre de Recherche en Cancérologie de Marseille, Inserm, CNRS, Aix-Marseille University, UMR1068, 13284 Marseille, France
| | - David A Lyons
- Centre for Neuroregeneration, Centre for Multiple Sclerosis Research, Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - Elior Peles
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel.
| | - Jonah R Chan
- Department of Neurology and Program in Neuroscience, University of California, San Francisco, San Francisco, CA 94143, USA.
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14
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G protein-coupled receptor 37 is a negative regulator of oligodendrocyte differentiation and myelination. Nat Commun 2016; 7:10884. [PMID: 26961174 PMCID: PMC4792952 DOI: 10.1038/ncomms10884] [Citation(s) in RCA: 89] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 01/29/2016] [Indexed: 12/22/2022] Open
Abstract
While the formation of myelin by oligodendrocytes is critical for the function of the
central nervous system, the molecular mechanism controlling oligodendrocyte
differentiation remains largely unknown. Here we identify G protein-coupled receptor
37 (GPR37) as an inhibitor of late-stage oligodendrocyte differentiation and
myelination. GPR37 is enriched in oligodendrocytes and its expression increases
during their differentiation into myelin forming cells. Genetic deletion of
Gpr37 does not affect the number of oligodendrocyte precursor cells, but
results in precocious oligodendrocyte differentiation and hypermyelination. The
inhibition of oligodendrocyte differentiation by GPR37 is mediated by suppression of
an exchange protein activated by cAMP (EPAC)-dependent activation of Raf-MAPK-ERK1/2
module and nuclear translocation of ERK1/2. Our data suggest that GPR37 regulates
central nervous system myelination by controlling the transition from
early-differentiated to mature oligodendrocytes. The molecular mechanism controlling oligodendrocyte differentiation is
not fully understood. Here the authors show that G protein coupled receptor 37 acts as a
negative regulator of CNS myelination, and this effect is mediated by suppression of ERK
signalling.
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15
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Rassul SM, Neely RK, Fulton D. Live-imaging in the CNS: New insights on oligodendrocytes, myelination, and their responses to inflammation. Neuropharmacology 2015; 110:594-604. [PMID: 26407765 DOI: 10.1016/j.neuropharm.2015.09.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Revised: 07/31/2015] [Accepted: 09/08/2015] [Indexed: 11/18/2022]
Abstract
The formation and repair of myelin involves alterations in the molecular and physical properties of oligodendrocytes, and highly coordinated interactions with their target axons. Characterising the nature and timing of these events at the molecular and cellular levels illuminates the fundamental events underlying myelin formation, and provides opportunities for the development of therapies to replace myelin lost through traumatic injury and inflammation. The dynamic nature of these events requires that live-imaging methods be used to capture this information accurately and completely. Developments in imaging technologies, and model systems suitable for their application to myelination, have advanced the study of myelin formation, injury and repair. Similarly, new techniques for single molecule imaging, and novel imaging probes, are providing opportunities to resolve the dynamics of myelin proteins during myelination. Here, we explore these developments in the context of myelin formation and injury, identify unmet needs within the field where progress can be advanced through live-imaging approaches, identify technical challenges that are limiting this progress, and highlight practical applications for these approaches that could lead to therapies for the protection of oligodendrocytes and myelin from injury, and restore myelin lost through injury and disease. This article is part of the Special Issue entitled 'Oligodendrocytes in Health and Disease'.
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Affiliation(s)
- Sayed Muhammed Rassul
- Physical Sciences of Imaging in the Biomedical Sciences Training Programme, University of Birmingham, Birmingham, UK
| | - Robert K Neely
- School of Chemistry, University of Birmingham, Birmingham, UK
| | - Daniel Fulton
- Neurotrauma Research Group, Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK.
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16
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Michalski JP, Kothary R. Oligodendrocytes in a Nutshell. Front Cell Neurosci 2015; 9:340. [PMID: 26388730 PMCID: PMC4556025 DOI: 10.3389/fncel.2015.00340] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 08/17/2015] [Indexed: 01/06/2023] Open
Abstract
Oligodendrocytes are the myelinating cells of the central nervous system (CNS). While the phrase is oft repeated and holds true, the last few years have borne witness to radical change in our understanding of this unique cell type. Once considered static glue, oligodendrocytes are now seen as plastic and adaptive, capable of reacting to a changing CNS. This review is intended as a primer and guide, exploring how the past 5 years have fundamentally altered our appreciation of oligodendrocyte development and CNS myelination.
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Affiliation(s)
- John-Paul Michalski
- Ottawa Hospital Research Institute , Ottawa, ON , Canada ; Department of Cellular and Molecular Medicine, University of Ottawa , Ottawa, ON , Canada
| | - Rashmi Kothary
- Ottawa Hospital Research Institute , Ottawa, ON , Canada ; Department of Cellular and Molecular Medicine, University of Ottawa , Ottawa, ON , Canada ; Department of Medicine, University of Ottawa , Ottawa, ON , Canada ; Centre for Neuromuscular Disease, University of Ottawa , Ottawa, ON , Canada
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17
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Abstract
Myelinated nerve fibers have evolved to enable fast and efficient transduction of electrical signals in the nervous system. To act as an electric insulator, the myelin sheath is formed as a multilamellar membrane structure by the spiral wrapping and subsequent compaction of the oligodendroglial plasma membrane around central nervous system (CNS) axons. Current evidence indicates that the myelin sheath is more than an inert insulating membrane structure. Oligodendrocytes are metabolically active and functionally connected to the subjacent axon via cytoplasmic-rich myelinic channels for movement of macromolecules to and from the internodal periaxonal space under the myelin sheath. This review summarizes our current understanding of how myelin is generated and also the role of oligodendrocytes in supporting the long-term integrity of myelinated axons.
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Affiliation(s)
- Mikael Simons
- Cellular Neuroscience, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany Department of Neurology, University of Göttingen, 37075 Göttingen, Germany
| | - Klaus-Armin Nave
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
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18
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Kerman BE, Kim HJ, Padmanabhan K, Mei A, Georges S, Joens MS, Fitzpatrick JAJ, Jappelli R, Chandross KJ, August P, Gage FH. In vitro myelin formation using embryonic stem cells. Development 2015; 142:2213-25. [PMID: 26015546 DOI: 10.1242/dev.116517] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Accepted: 04/21/2015] [Indexed: 01/21/2023]
Abstract
Myelination in the central nervous system is the process by which oligodendrocytes form myelin sheaths around the axons of neurons. Myelination enables neurons to transmit information more quickly and more efficiently and allows for more complex brain functions; yet, remarkably, the underlying mechanism by which myelination occurs is still not fully understood. A reliable in vitro assay is essential to dissect oligodendrocyte and myelin biology. Hence, we developed a protocol to generate myelinating oligodendrocytes from mouse embryonic stem cells and established a myelin formation assay with embryonic stem cell-derived neurons in microfluidic devices. Myelin formation was quantified using a custom semi-automated method that is suitable for larger scale analysis. Finally, early myelination was followed in real time over several days and the results have led us to propose a new model for myelin formation.
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Affiliation(s)
- Bilal E Kerman
- Laboratory of Genetics, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Hyung Joon Kim
- Laboratory of Genetics, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Krishnan Padmanabhan
- Laboratory of Genetics, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA Computational Neuroscience Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA Crick Jacobs Center for Theoretical and Computational Biology, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Arianna Mei
- Laboratory of Genetics, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Shereen Georges
- Laboratory of Genetics, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Matthew S Joens
- Waitt Advanced Biophotonics Center, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - James A J Fitzpatrick
- Waitt Advanced Biophotonics Center, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Roberto Jappelli
- Laboratory of Genetics, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Karen J Chandross
- Sanofi US, R&D, Genzyme MS/Neurology, 55 Corporate Drive, Bridgewater, NJ 08807, USA
| | - Paul August
- Sanofi US, R&D, Early to Candidate Unit, Tucson Innovation Center, 2090 E. Innovation Park Drive, Tucson, AZ 85755, USA
| | - Fred H Gage
- Laboratory of Genetics, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
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19
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Abstract
The myelin sheath is a plasma membrane extension that is laid down in regularly spaced segments along axons of the nervous system. This process involves extensive changes in oligodendrocyte cell shape and membrane architecture. In this Cell Science at a Glance article and accompanying poster, we provide a model of how myelin of the central nervous system is wrapped around axons to form a tightly compacted, multilayered membrane structure. This model may not only explain how myelin is generated during brain development, but could also help us to understand myelin remodeling in adult life, which might serve as a form of plasticity for the fine-tuning of neuronal networks.
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Affiliation(s)
- Nicolas Snaidero
- Max Planck Institute of Experimental Medicine, Cellular Neuroscience, Hermann-Rein-Strasse. 3, 37075, Göttingen, Germany Department of Neurology, University of Göttingen, Robert-Koch-Strasse. 40, 37075, Göttingen, Germany
| | - Mikael Simons
- Max Planck Institute of Experimental Medicine, Cellular Neuroscience, Hermann-Rein-Strasse. 3, 37075, Göttingen, Germany Department of Neurology, University of Göttingen, Robert-Koch-Strasse. 40, 37075, Göttingen, Germany
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20
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Szuchet S, Nielsen LL, Domowicz MS, Austin JR, Arvanitis DL. CNS myelin sheath is stochastically built by homotypic fusion of myelin membranes within the bounds of an oligodendrocyte process. J Struct Biol 2015; 190:56-72. [PMID: 25682762 DOI: 10.1016/j.jsb.2015.01.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Revised: 01/25/2015] [Accepted: 01/27/2015] [Indexed: 02/09/2023]
Abstract
Myelin - the multilayer membrane that envelops axons - is a facilitator of rapid nerve conduction. Oligodendrocytes form CNS myelin; the prevailing hypothesis being that they do it by extending a process that circumnavigates the axon. It is pertinent to ask how myelin is built because oligodendrocyte plasma membrane and myelin are compositionally different. To this end, we examined oligodendrocyte cultures and embryonic avian optic nerves by electron microscopy, immuno-electron microscopy and three-dimensional electron tomography. The results support three novel concepts. Myelin membranes are synthesized as tubules and packaged into "myelinophore organelles" in the oligodendrocyte perikaryon. Myelin membranes are matured in and transported by myelinophore organelles within an oligodendrocyte process. The myelin sheath is generated by myelin membrane fusion inside an oligodendrocyte process. These findings abrogate the dogma of myelin resulting from a wrapping motion of an oligodendrocyte process and open up new avenues in the quest for understanding myelination in health and disease.
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Affiliation(s)
- Sara Szuchet
- Department of Neurology, The University of Chicago, Chicago, IL 60637, USA.
| | - Lauren L Nielsen
- Department of Neurology, The University of Chicago, Chicago, IL 60637, USA
| | - Miriam S Domowicz
- Department of Pediatrics, The University of Chicago, Chicago, IL 60637, USA
| | - Jotham R Austin
- Advance Electron Microscopy Facility, Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, IL 60637, USA
| | - Dimitrios L Arvanitis
- Department of Anatomy, Histology, Embryology, University of Thessaly, Larissa, Greece
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21
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Caspr and caspr2 are required for both radial and longitudinal organization of myelinated axons. J Neurosci 2015; 34:14820-6. [PMID: 25378149 DOI: 10.1523/jneurosci.3369-14.2014] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
In myelinated peripheral axons, Kv1 potassium channels are clustered at the juxtaparanodal region and at an internodal line located along the mesaxon and below the Schmidt-Lanterman incisures. This polarized distribution is controlled by Schwann cells and requires specific cell adhesion molecules (CAMs). The accumulation of Kv1 channels at the juxtaparanodal region depends on the presence of Caspr2 at this site, as well as on the presence of Caspr at the adjacent paranodal junction. However, the localization of these channels along the mesaxonal internodal line still persists in the absence of each one of these CAMs. By generating mice lacking both Caspr and Caspr2 (caspr(-/-)/caspr2(-/-)), we now reveal compensatory functions of the two proteins in the organization of the axolemma. Although Kv1 channels are clustered along the inner mesaxon and in a circumferential ring below the incisures in the single mutants, in sciatic nerves of caspr(-/-)/caspr2(-/-) mice, these channels formed large aggregates that were dispersed along the axolemma, demonstrating that internodal localization of Kv1 channels requires either Caspr or Caspr2. Furthermore, deletion of both Caspr and Caspr2 also resulted in widening of the nodes of Ranvier, suggesting that Caspr2 (which is present at paranodes in the absence of Caspr) can partially compensate for the barrier function of Caspr at this site even without the formation of a distinct paranodal junction. Our results indicate that Caspr and Caspr2 are required for the organization of the axolemma both radially, manifested as the mesaxonal line, and longitudinally, demarcated by the nodal domains.
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22
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Label-free imaging of Schwann cell myelination by third harmonic generation microscopy. Proc Natl Acad Sci U S A 2014; 111:18025-30. [PMID: 25453108 DOI: 10.1073/pnas.1417820111] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Understanding the dynamic axon-glial cell interaction underlying myelination is hampered by the lack of suitable imaging techniques. Here we demonstrate third harmonic generation microscopy (THGM) for label-free imaging of myelinating Schwann cells in live culture and ex vivo and in vivo tissue. A 3D structure was acquired for a variety of compact and noncompact myelin domains, including juxtaparanodes, Schmidt-Lanterman incisures, and Cajal bands. Other subcellular features of Schwann cells that escape traditional optical microscopies were also visualized. We tested THGM for morphometry of compact myelin. Unlike current methods based on electron microscopy, g-ratio could be determined along an extended length of myelinated fiber in the physiological condition. The precision of THGM-based g-ratio estimation was corroborated in mouse models of hypomyelination. Finally, we demonstrated the feasibility of THGM to monitor morphological changes of myelin during postnatal development and degeneration. The outstanding capabilities of THGM may be useful for elucidation of the mechanism of myelin formation and pathogenesis.
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23
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Snaidero N, Möbius W, Czopka T, Hekking LHP, Mathisen C, Verkleij D, Goebbels S, Edgar J, Merkler D, Lyons DA, Nave KA, Simons M. Myelin membrane wrapping of CNS axons by PI(3,4,5)P3-dependent polarized growth at the inner tongue. Cell 2014; 156:277-90. [PMID: 24439382 DOI: 10.1016/j.cell.2013.11.044] [Citation(s) in RCA: 275] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Revised: 10/05/2013] [Accepted: 11/07/2013] [Indexed: 12/21/2022]
Abstract
Central nervous system myelin is a multilayered membrane sheath generated by oligodendrocytes for rapid impulse propagation. However, the underlying mechanisms of myelin wrapping have remained unclear. Using an integrative approach of live imaging, electron microscopy, and genetics, we show that new myelin membranes are incorporated adjacent to the axon at the innermost tongue. Simultaneously, newly formed layers extend laterally, ultimately leading to the formation of a set of closely apposed paranodal loops. An elaborated system of cytoplasmic channels within the growing myelin sheath enables membrane trafficking to the leading edge. Most of these channels close with ongoing development but can be reopened in adults by experimentally raising phosphatidylinositol-(3,4,5)-triphosphate levels, which reinitiates myelin growth. Our model can explain assembly of myelin as a multilayered structure, abnormal myelin outfoldings in neurological disease, and plasticity of myelin biogenesis observed in adult life.
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Affiliation(s)
- Nicolas Snaidero
- Max Planck Institute of Experimental Medicine, Cellular Neuroscience, Hermann-Rein-Strasse, 3, 37075 Göttingen, Germany; Department of Neurology, University of Göttingen, Robert-Koch-Strasse, 40, 37075 Göttingen, Germany
| | - Wiebke Möbius
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Hermann-Rein-Strasse, 3, 37075 Göttingen, Germany; Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), 37075 Göttingen, Germany
| | - Tim Czopka
- Centre for Neuroregeneration, University of Edinburgh, Edinburgh EH16 4SB, UK; MS Society Centre for Translational Research, University of Edinburgh, Edinburgh EH16 4SB, UK; Euan Mac Donald Centre for Motor Neurone Disease Research, University of Edinburgh, Edinburgh EH16 4SB, UK; MRC Centre for Regenerative Medicine, University of Edinburgh, Edinburgh EH16 4UU, UK
| | | | - Cliff Mathisen
- FEI Company, Achtseweg Noord 5, 5651 GG Eindhoven, The Netherlands
| | - Dick Verkleij
- FEI Company, Achtseweg Noord 5, 5651 GG Eindhoven, The Netherlands
| | - Sandra Goebbels
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Hermann-Rein-Strasse, 3, 37075 Göttingen, Germany
| | - Julia Edgar
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Hermann-Rein-Strasse, 3, 37075 Göttingen, Germany
| | - Doron Merkler
- Department of Pathology and Immunology, University of Geneva, 1211 Geneva, Switzerland; Division of Clinical Pathology, Geneva University Hospital, 1211 Geneva, Switzerland; Department of Neuropathology, University of Göttingen, 37075 Göttingen, Germany
| | - David A Lyons
- Centre for Neuroregeneration, University of Edinburgh, Edinburgh EH16 4SB, UK; MS Society Centre for Translational Research, University of Edinburgh, Edinburgh EH16 4SB, UK; Euan Mac Donald Centre for Motor Neurone Disease Research, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - Klaus-Armin Nave
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Hermann-Rein-Strasse, 3, 37075 Göttingen, Germany
| | - Mikael Simons
- Max Planck Institute of Experimental Medicine, Cellular Neuroscience, Hermann-Rein-Strasse, 3, 37075 Göttingen, Germany; Department of Neurology, University of Göttingen, Robert-Koch-Strasse, 40, 37075 Göttingen, Germany.
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24
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Simons M, Lyons DA. Axonal selection and myelin sheath generation in the central nervous system. Curr Opin Cell Biol 2013; 25:512-9. [PMID: 23707197 DOI: 10.1016/j.ceb.2013.04.007] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Revised: 04/04/2013] [Accepted: 04/24/2013] [Indexed: 01/06/2023]
Abstract
The formation of myelin in the central nervous system is a multi-step process that involves coordinated cell-cell interactions and dramatic changes in plasma membrane architecture. First, oligodendrocytes send our numerous highly ramified processes to sample the axonal environment and decide which axon(s) to select for myelination. After this decision is made and individual axon to oligodendrocyte contact has been established, the exploratory process of the oligodendrocyte is converted into a flat sheath that spreads and winds along and around its associated axon to generate a multilayered membrane stack. By compaction of the opposing extracellular layers of membrane and extrusion of almost all cytoplasm from the intracellular domain of the sheath, the characteristic membrane-rich multi-lamellar structure of myelin is formed. Here we highlight recent advances in identifying biophysical and signalling based mechanisms that are involved in axonal selection and myelin sheath generation by oligodendrocytes. A thorough understanding of the mechanisms underlying these events is a prerequisite for the design of novel myelin repair strategies in demyelinating and dysmyelinating diseases.
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Affiliation(s)
- Mikael Simons
- Max-Planck-Institute for Experimental Medicine, Hermann-Rein-Str. 3, Göttingen, Germany.
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25
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Ioannidou K, Anderson KI, Strachan D, Edgar JM, Barnett SC. Time-lapse imaging of the dynamics of CNS glial-axonal interactions in vitro and ex vivo. PLoS One 2012; 7:e30775. [PMID: 22303455 PMCID: PMC3267745 DOI: 10.1371/journal.pone.0030775] [Citation(s) in RCA: 36] [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: 10/07/2011] [Accepted: 12/26/2011] [Indexed: 12/03/2022] Open
Abstract
Background Myelination is an exquisite and dynamic example of heterologous cell-cell interaction, which consists of the concentric wrapping of multiple layers of oligodendrocyte membrane around neuronal axons. Understanding the mechanism by which oligodendrocytes ensheath axons may bring us closer to designing strategies to promote remyelination in demyelinating diseases. The main aim of this study was to follow glial-axonal interactions over time both in vitro and ex vivo to visualize the various stages of myelination. Methodology/Principal Findings We took two approaches to follow myelination over time: i) time-lapse imaging of mixed CNS myelinating cultures generated from mouse spinal cord to which exogenous GFP-labelled murine cells were added, and ii) ex vivo imaging of the spinal cord of shiverer (Mbp mutant) mice, transplanted with GFP-labelled murine neurospheres. We demonstrate that oligodendrocyte-axonal interactions are dynamic events with continuous retraction and extension of oligodendroglial processes. Using cytoplasmic and membrane-GFP labelled cells to examine different components of the myelin-like sheath, we provide evidence from time-lapse fluorescence microscopy and confocal microscopy that the oligodendrocytes' cytoplasm-filled processes initially spiral around the axon in a corkscrew-like manner. This is followed subsequently by focal expansion of the corkscrew process to form short cuffs, which then extend longitudinally along the axons. We predict from this model that these spiral cuffs must extend over each other first before extending to form internodes of myelin. Conclusion These experiments show the feasibility of visualizing the dynamics of glial-axonal interaction during myelination over time. Moreover, these approaches complement each other with the in vitro approach allowing visualization of an entire internodal length of myelin and the ex vivo approach validating the in vitro data.
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Affiliation(s)
- Kalliopi Ioannidou
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Kurt I. Anderson
- Institute of Cancer Sciences, The Beatson Institute for Cancer Research, Glasgow, United Kingdom
| | - David Strachan
- Institute of Cancer Sciences, The Beatson Institute for Cancer Research, Glasgow, United Kingdom
| | - Julia M. Edgar
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Susan C. Barnett
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
- * E-mail:
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26
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Sobottka B, Ziegler U, Kaech A, Becher B, Goebels N. CNS live imaging reveals a new mechanism of myelination: The liquid croissant model. Glia 2011; 59:1841-9. [DOI: 10.1002/glia.21228] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2011] [Accepted: 07/18/2011] [Indexed: 11/06/2022]
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27
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Jarjour AA, Zhang H, Bauer N, Ffrench-Constant C, Williams A. In vitro modeling of central nervous system myelination and remyelination. Glia 2011; 60:1-12. [PMID: 21858876 DOI: 10.1002/glia.21231] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2011] [Accepted: 07/26/2011] [Indexed: 12/14/2022]
Abstract
This review aims to summarize the current techniques to study myelination and remyelination in culture systems. We attempt to put these into historical context, and to identify the strengths and weaknesses of each approach, which vary depending on the experimental question to be tested. We discuss the difficulty and importance of quantification of myelination and in particular remyelination. Finally, we provide our predictions of how these techniques will and should develop in the future.
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Affiliation(s)
- Andrew A Jarjour
- MRC Centre for Regenerative Medicine, Edinburgh MS Centre, Queen's Medical Research Centre, Little France Crescent, Edinburgh, UK
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28
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Zoupi L, Savvaki M, Karagogeos D. Axons and myelinating glia: An intimate contact. IUBMB Life 2011; 63:730-5. [PMID: 21793162 DOI: 10.1002/iub.513] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2011] [Accepted: 04/18/2011] [Indexed: 01/06/2023]
Abstract
The coordination of the vertebrate nervous system requires high velocity signal transmission between different brain areas. High speed nerve conduction is achieved in the myelinated fibers of both the central and the peripheral nervous system where the myelin sheath acts as an insulator of the axon. The interactions between the glial cell and the adjacent axon, namely axo-glial interactions, segregate the fiber in distinct molecular and functional domains that ensure the rapid propagation of action potentials. These domains are the node of Ranvier, the paranode, the juxtaparanode and the internode and are characterized by multiprotein complexes between voltage-gated ion channels, cell adhesion molecules, members of the Neurexin family and cytoskeletal proteins. In the present review, we outline recent evidence on the key players of axo-glial interactions, depicting their importance in myelinated fiber physiology and disease.
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Affiliation(s)
- Lida Zoupi
- Department of Basic Science, Faculty of Medicine, University of Crete, Institute of Molecular Biology & Biotechnology-FoRTH, Heraklion, Greece
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Salzer J, Dunn R, Brophy P. David Colman: A Tribute. Neuron 2011. [DOI: 10.1016/j.neuron.2011.07.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Novak N, Bar V, Sabanay H, Frechter S, Jaegle M, Snapper SB, Meijer D, Peles E. N-WASP is required for membrane wrapping and myelination by Schwann cells. ACTA ACUST UNITED AC 2011; 192:243-50. [PMID: 21263026 PMCID: PMC3172181 DOI: 10.1083/jcb.201010013] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
N-WASP–deficient Schwann cells sort and ensheath axons but arrest at the promyelinating stage. During peripheral nerve myelination, Schwann cells sort larger axons, ensheath them, and eventually wrap their membrane to form the myelin sheath. These processes involve extensive changes in cell shape, but the exact mechanisms involved are still unknown. Neural Wiskott–Aldrich syndrome protein (N-WASP) integrates various extracellular signals to control actin dynamics and cytoskeletal reorganization through activation of the Arp2/3 complex. By generating mice lacking N-WASP in myelinating Schwann cells, we show that N-WASP is crucial for myelination. In N-WASP–deficient nerves, Schwann cells sort and ensheath axons, but most of them fail to myelinate and arrest at the promyelinating stage. Yet, a limited number of Schwann cells form unusually short internodes, containing thin myelin sheaths, with the occasional appearance of myelin misfoldings. These data suggest that regulation of actin filament nucleation in Schwann cells by N-WASP is crucial for membrane wrapping, longitudinal extension, and myelination.
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Affiliation(s)
- Nurit Novak
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 76100, Israel
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Response of human oligodendrocyte progenitors to growth factors and axon signals. J Neuropathol Exp Neurol 2010; 69:930-44. [PMID: 20720504 DOI: 10.1097/nen.0b013e3181ef3be4] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Abstract
We examined the effects of growth factors and axonal signals on the differentiation of human fetal and adult oligodendrocyte progenitor cells (OPCs) and determined whether these effects translated into enhanced axonal ensheathment. Only small numbers of fetal OPCs grown in defined medium expressed the oligodendroglial lineage markers Olig2 and O4. The combination of platelet-derived growth factor-AA and basic fibroblast growth factor enhanced proliferation of Olig2-positive and O4-positive cells; a combination of brain-derived neurotrophic factor and insulin-like growth factor 1 promoted O4-positive cell differentiation, galactocerebroside expression, and morphological complexity. Coculturing with rodent dorsal root ganglion neurons in defined medium alone enhanced OPC differentiation and myelin basic protein expression. The addition of brain-derived neurotrophic factor/insulin-like growth factor 1 further enhanced differentiation, axonal attachment and ensheathment, and clustering of the contactin-associated protein Caspr and Na+ channels. By contrast, most adult OPCs were O4 positive and Olig2 positive in defined medium; both brain-derived neurotrophic factor/insulin-like growth factor 1 and platelet-derived growth factor-AA/basic fibroblast growth factor promoted their myelin basic protein expression and membrane sheet formation; coculture with dorsal root ganglion neurons further increased myelin basic protein expression. Growth factors also enhanced attachment of adult OPCs to axons, but their capacity to ensheath axons was lower than that of fetal OPCs. These results demonstrate that fetal and adult OPCs show measurable responses to selected growth factors and axon signals that correlate with their capacity for axon ensheathment. The distinct properties of fetal and adult OPCs may be related to differences in their chronological age and initial differentiation states.
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Eisenbach M, Kartvelishvily E, Eshed-Eisenbach Y, Watkins T, Sorensen A, Thomson C, Ranscht B, Barnett SC, Brophy P, Peles E. Differential clustering of Caspr by oligodendrocytes and Schwann cells. J Neurosci Res 2010; 87:3492-501. [PMID: 19565653 DOI: 10.1002/jnr.22157] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Formation of the paranodal axoglial junction (PNJ) requires the presence of three cell adhesion molecules: the 155-kDa isoform of neurofascin (NF155) on the glial membrane and a complex of Caspr and contactin found on the axolemma. Here we report that the clustering of Caspr along myelinated axons during development differs fundamentally between the central (CNS) and peripheral (PNS) nervous systems. In cultures of Schwann cells (SC) and dorsal root ganglion (DRG) neurons, membrane accumulation of Caspr was detected only after myelination. In contrast, in oligodendrocytes (OL)/DRG neurons cocultures, Caspr was clustered upon initial glial cell contact already before myelination had begun. Premyelination clustering of Caspr was detected in cultures of oligodendrocytes and retinal ganglion cells, motor neurons, and DRG neurons as well as in mixed cell cultures of rat forebrain and spinal cords. Cocultures of oligodendrocyte precursor cells isolated from contactin- or neurofascin-deficient mice with wild-type DRG neurons showed that clustering of Caspr at initial contact sites between OL processes and the axon requires glial expression of NF155 but not of contactin. These results demonstrate that the expression of membrane proteins along the axolemma is determined by the type of the contacting glial cells and is not an intrinsic characteristic of the axon.
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Affiliation(s)
- Menahem Eisenbach
- Department of Molecular Cell Biology, The Weizmann Institute of Science, Rehovot, Israel
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On the biogenesis of myelin membranes: sorting, trafficking and cell polarity. FEBS Lett 2009; 584:1760-70. [PMID: 19896485 DOI: 10.1016/j.febslet.2009.10.085] [Citation(s) in RCA: 112] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2009] [Revised: 10/29/2009] [Accepted: 10/30/2009] [Indexed: 11/22/2022]
Abstract
In the central nervous system, a multilayered membrane layer known as the myelin sheath enwraps axons, and is required for optimal saltatory signal conductance. The sheath develops from membrane processes that extend from the plasma membrane of oligodendrocytes and displays a unique lipid and protein composition. Myelin biogenesis is carefully regulated, and multiple transport pathways involving a variety of endosomal compartments are involved. Here we briefly summarize how the major myelin proteins proteolipid protein and myelin basic protein reach the sheath, and highlight potential mechanisms involved, including the role of myelin specific lipids and cell polarity related transport pathways.
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