1
|
Schwann cell functions in peripheral nerve development and repair. Neurobiol Dis 2023; 176:105952. [PMID: 36493976 DOI: 10.1016/j.nbd.2022.105952] [Citation(s) in RCA: 36] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 11/23/2022] [Accepted: 12/05/2022] [Indexed: 12/12/2022] Open
Abstract
The glial cell of the peripheral nervous system (PNS), the Schwann cell (SC), counts among the most multifaceted cells of the body. During development, SCs secure neuronal survival and participate in axonal path finding. Simultaneously, they orchestrate the architectural set up of the developing nerves, including the blood vessels and the endo-, peri- and epineurial layers. Perinatally, in rodents, SCs radially sort and subsequently myelinate individual axons larger than 1 μm in diameter, while small calibre axons become organised in non-myelinating Remak bundles. SCs have a vital role in maintaining axonal health throughout life and several specialized SC types perform essential functions at specific locations, such as terminal SC at the neuromuscular junction (NMJ) or SC within cutaneous sensory end organs. In addition, neural crest derived satellite glia maintain a tight communication with the soma of sensory, sympathetic, and parasympathetic neurons and neural crest derivatives are furthermore an indispensable part of the enteric nervous system. The remarkable plasticity of SCs becomes evident in the context of a nerve injury, where SC transdifferentiate into intriguing repair cells, which orchestrate a regenerative response that promotes nerve repair. Indeed, the multiple adaptations of SCs are captivating, but remain often ill-resolved on the molecular level. Here, we summarize and discuss the knowns and unknowns of the vast array of functions that this single cell type can cover in peripheral nervous system development, maintenance, and repair.
Collapse
|
2
|
Song H, McEwan PP, Ameen-Ali KE, Tomasevich A, Kennedy-Dietrich C, Palma A, Arroyo EJ, Dolle JP, Johnson VE, Stewart W, Smith DH. Concussion leads to widespread axonal sodium channel loss and disruption of the node of Ranvier. Acta Neuropathol 2022; 144:967-985. [PMID: 36107227 PMCID: PMC9547928 DOI: 10.1007/s00401-022-02498-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 09/08/2022] [Accepted: 09/08/2022] [Indexed: 01/26/2023]
Abstract
Despite being a major health concern, little is known about the pathophysiological changes that underly concussion. Nonetheless, emerging evidence suggests that selective damage to white matter axons, or diffuse axonal injury (DAI), disrupts brain network connectivity and function. While voltage-gated sodium channels (NaChs) and their anchoring proteins at the nodes of Ranvier (NOR) on axons are key elements of the brain's network signaling machinery, changes in their integrity have not been studied in context with DAI. Here, we utilized a clinically relevant swine model of concussion that induces evolving axonal pathology, demonstrated by accumulation of amyloid precursor protein (APP) across the white matter. Over a two-week follow-up post-concussion with this model, we found widespread loss of NaCh isoform 1.6 (Nav1.6), progressive increases in NOR length, the appearance of void and heminodes and loss of βIV-spectrin, ankyrin G, and neurofascin 186 or their collective diffusion into the paranode. Notably, these changes were in close proximity, yet distinct from APP-immunoreactive swollen axonal profiles, potentially representing a unique, newfound phenotype of axonal pathology in DAI. Since concussion in humans is non-fatal, the clinical relevance of these findings was determined through examination of post-mortem brain tissue from humans with higher levels of acute traumatic brain injury. Here, a similar loss of Nav1.6 and changes in NOR structures in brain white matter were observed as found in the swine model of concussion. Collectively, this widespread and progressive disruption of NaChs and NOR appears to be a form of sodium channelopathy, which may represent an important substrate underlying brain network dysfunction after concussion.
Collapse
Affiliation(s)
- Hailong Song
- Department of Neurosurgery, Center for Brain Injury and Repair, University of Pennsylvania, 3320 Smith Walk, 105 Hayden Hall, Philadelphia, PA, 19104, USA
| | - Przemyslaw P McEwan
- Department of Neurosurgery, Center for Brain Injury and Repair, University of Pennsylvania, 3320 Smith Walk, 105 Hayden Hall, Philadelphia, PA, 19104, USA
| | - Kamar E Ameen-Ali
- School of Neuroscience and Psychology, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Alexandra Tomasevich
- Department of Neurosurgery, Center for Brain Injury and Repair, University of Pennsylvania, 3320 Smith Walk, 105 Hayden Hall, Philadelphia, PA, 19104, USA
| | | | - Alexander Palma
- Department of Neurosurgery, Center for Brain Injury and Repair, University of Pennsylvania, 3320 Smith Walk, 105 Hayden Hall, Philadelphia, PA, 19104, USA
| | - Edgardo J Arroyo
- Department of Neurosurgery, Center for Brain Injury and Repair, University of Pennsylvania, 3320 Smith Walk, 105 Hayden Hall, Philadelphia, PA, 19104, USA
| | - Jean-Pierre Dolle
- Department of Neurosurgery, Center for Brain Injury and Repair, University of Pennsylvania, 3320 Smith Walk, 105 Hayden Hall, Philadelphia, PA, 19104, USA
| | - Victoria E Johnson
- Department of Neurosurgery, Center for Brain Injury and Repair, University of Pennsylvania, 3320 Smith Walk, 105 Hayden Hall, Philadelphia, PA, 19104, USA
| | - William Stewart
- School of Neuroscience and Psychology, University of Glasgow, Glasgow, G12 8QQ, UK
- Department of Neuropathology, Queen Elizabeth University Hospital, Glasgow, G51 4TF, UK
| | - Douglas H Smith
- Department of Neurosurgery, Center for Brain Injury and Repair, University of Pennsylvania, 3320 Smith Walk, 105 Hayden Hall, Philadelphia, PA, 19104, USA.
| |
Collapse
|
3
|
Lethal Congenital Contracture Syndrome 11: A Case Report and Literature Review. J Clin Med 2022; 11:jcm11133570. [PMID: 35806855 PMCID: PMC9267849 DOI: 10.3390/jcm11133570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 06/15/2022] [Accepted: 06/20/2022] [Indexed: 02/05/2023] Open
Abstract
Lethal congenital contracture syndrome 11 (LCCS11) is caused by homozygous or compound heterozygous variants in the GLDN gene on chromosome 15q21. GLDN encodes gliomedin, a protein required for the formation of the nodes of Ranvier and development of the human peripheral nervous system. We report a fetus with ultrasound alterations detected at 28 weeks of gestation. The fetus exhibited hydrops, short long bones, fixed limb joints, absent fetal movements, and polyhydramnios. The pregnancy was terminated and postmortem studies confirmed the prenatal findings: distal arthrogryposis, fetal growth restriction, pulmonary hypoplasia, and retrognathia. The fetus had a normal chromosomal microarray analysis. Exome sequencing revealed two novel compound heterozygous variants in the GLDN associated with LCCS11. This manuscript reports this case and performs a literature review of all published LCCS11 cases.
Collapse
|
4
|
Gao Y, Kong L, Liu S, Liu K, Zhu J. Impact of Neurofascin on Chronic Inflammatory Demyelinating Polyneuropathy via Changing the Node of Ranvier Function: A Review. Front Mol Neurosci 2022; 14:779385. [PMID: 34975399 PMCID: PMC8716720 DOI: 10.3389/fnmol.2021.779385] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Accepted: 11/15/2021] [Indexed: 11/18/2022] Open
Abstract
The effective conduction of action potential in the peripheral nervous system depends on the structural and functional integrity of the node of Ranvier and paranode. Neurofascin (NF) plays an important role in the conduction of action potential in a saltatory manner. Two subtypes of NF, NF186, and NF155, are involved in the structure of the node of Ranvier. In patients with chronic inflammatory demyelinating polyneuropathy (CIDP), anti-NF antibodies are produced when immunomodulatory dysfunction occurs, which interferes with the conduction of action potential and is considered the main pathogenic factor of CIDP. In this study, we describe the assembling mechanism and anatomical structure of the node of Ranvier and the necessary cell adhesion molecules for its physiological function. The main points of this study are that we summarized the recent studies on the role of anti-NF antibodies in the changes in the node of Ranvier function and its impact on clinical manifestations and analyzed the possible mechanisms underlying the pathogenesis of CIDP.
Collapse
Affiliation(s)
- Ying Gao
- Neuroscience Center, Department of Neurology, The First Hospital of Jilin University, Jilin University, Changchun, China
| | - Lingxin Kong
- Neuroscience Center, Department of Neurology, The First Hospital of Jilin University, Jilin University, Changchun, China
| | - Shan Liu
- Neuroscience Center, Department of Neurology, The First Hospital of Jilin University, Jilin University, Changchun, China
| | - Kangding Liu
- Neuroscience Center, Department of Neurology, The First Hospital of Jilin University, Jilin University, Changchun, China
| | - Jie Zhu
- Neuroscience Center, Department of Neurology, The First Hospital of Jilin University, Jilin University, Changchun, China.,Department of Neurobiology, Care Sciences and Society, Karolinska Institute, Karolinska University Hospital Solna, Stockholm, Sweden
| |
Collapse
|
5
|
Malavasi EL, Ghosh A, Booth DG, Zagnoni M, Sherman DL, Brophy PJ. Dynamic early clusters of nodal proteins contribute to node of Ranvier assembly during myelination of peripheral neurons. eLife 2021; 10:68089. [PMID: 34240706 PMCID: PMC8289411 DOI: 10.7554/elife.68089] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 07/07/2021] [Indexed: 12/31/2022] Open
Abstract
Voltage-gated sodium channels cluster in macromolecular complexes at nodes of Ranvier to promote rapid nerve impulse conduction in vertebrate nerves. Node assembly in peripheral nerves is thought to be initiated at heminodes at the extremities of myelinating Schwann cells, and fusion of heminodes results in the establishment of nodes. Here we show that assembly of 'early clusters' of nodal proteins in the murine axonal membrane precedes heminode formation. The neurofascin (Nfasc) proteins are essential for node assembly, and the formation of early clusters also requires neuronal Nfasc. Early clusters are mobile and their proteins are dynamically recruited by lateral diffusion. They can undergo fusion not only with each other but also with heminodes, thus contributing to the development of nodes in peripheral axons. The formation of early clusters constitutes the earliest stage in peripheral node assembly and expands the repertoire of strategies that have evolved to establish these essential structures.
Collapse
Affiliation(s)
- Elise Lv Malavasi
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Aniket Ghosh
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Daniel G Booth
- Biodiscovery Institute, University of Nottingham, Nottingham, United Kingdom
| | - Michele Zagnoni
- Centre for Microsystems & Photonics, Dept. Electronic and Electrical Engineering, University of Strathclyde, Strathclyde, United Kingdom
| | - Diane L Sherman
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Peter J Brophy
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
| |
Collapse
|
6
|
Abstract
The nodes of Ranvier have clustered Na+ and K+ channels necessary for rapid and efficient axonal action potential conduction. However, detailed mechanisms of channel clustering have only recently been identified: they include two independent axon-glia interactions that converge on distinct axonal cytoskeletons. Here, we discuss how glial cell adhesion molecules and the extracellular matrix molecules that bind them assemble combinations of ankyrins, spectrins and other cytoskeletal scaffolding proteins, which cluster ion channels. We present a detailed molecular model, incorporating these overlapping mechanisms, to explain how the nodes of Ranvier are assembled in both the peripheral and central nervous systems.
Collapse
|
7
|
Eshed-Eisenbach Y, Devaux J, Vainshtein A, Golani O, Lee SJ, Feinberg K, Sukhanov N, Greenspan DS, Susuki K, Rasband MN, Peles E. Precise Spatiotemporal Control of Nodal Na + Channel Clustering by Bone Morphogenetic Protein-1/Tolloid-like Proteinases. Neuron 2020; 106:806-815.e6. [PMID: 32209430 DOI: 10.1016/j.neuron.2020.03.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 01/30/2020] [Accepted: 03/02/2020] [Indexed: 01/31/2023]
Abstract
During development of the peripheral nervous system (PNS), Schwann-cell-secreted gliomedin induces the clustering of Na+ channels at the edges of each myelin segment to form nodes of Ranvier. Here we show that bone morphogenetic protein-1 (BMP1)/Tolloid (TLD)-like proteinases confine Na+ channel clustering to these sites by negatively regulating the activity of gliomedin. Eliminating the Bmp1/TLD cleavage site in gliomedin or treating myelinating cultures with a Bmp1/TLD inhibitor results in the formation of numerous ectopic Na+ channel clusters along axons that are devoid of myelin segments. Furthermore, genetic deletion of Bmp1 and Tll1 genes in mice using a Schwann-cell-specific Cre causes ectopic clustering of nodal proteins, premature formation of heminodes around early ensheathing Schwann cells, and altered nerve conduction during development. Our results demonstrate that by inactivating gliomedin, Bmp1/TLD functions as an additional regulatory mechanism to ensure the correct spatial and temporal assembly of PNS nodes of Ranvier.
Collapse
Affiliation(s)
- Yael Eshed-Eisenbach
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Jerome Devaux
- INSERM U1051, Institut des Neurosciences de Montpellier (INM), Université de Montpellier, 34295 Montpellier, France
| | - Anna Vainshtein
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Ofra Golani
- Department of Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Se-Jin Lee
- The Jackson Laboratory and Department of Genetics and Genome Sciences, University of Connecticut School of Medicine, Farmington, CT 06032, USA
| | - Konstantin Feinberg
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Natasha Sukhanov
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Daniel S Greenspan
- Department of Cell and Regenerative Biology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
| | - Keiichiro Susuki
- Department of Neuroscience, Cell Biology, and Physiology, Boonshoft School of Medicine, Wright State University, Dayton, OH 45435, USA
| | - Matthew N Rasband
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
| | - Elior Peles
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 76100, Israel.
| |
Collapse
|
8
|
Burbach JPH, Meijer DH. Latrophilin's Social Protein Network. Front Neurosci 2019; 13:643. [PMID: 31297045 PMCID: PMC6608557 DOI: 10.3389/fnins.2019.00643] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Accepted: 06/05/2019] [Indexed: 01/06/2023] Open
Abstract
Latrophilins (LPHNs) are adhesion GPCRs that are originally discovered as spider's toxin receptors, but are now known to be involved in brain development and linked to several neuronal and non-neuronal disorders. Latrophilins act in conjunction with other cell adhesion molecules and may play a leading role in its network organization. Here, we focus on the main protein partners of latrophilins, namely teneurins, FLRTs and contactins and summarize their respective temporal and spatial expression patterns, links to neurodevelopmental disorders as well as their structural characteristics. We discuss how more recent insights into the separate cell biological functions of these proteins shed light on the central role of latrophilins in this network. We postulate that latrophilins control the refinement of synaptic properties of specific subtypes of neurons, requiring discrete combinations of proteins.
Collapse
Affiliation(s)
- J Peter H Burbach
- Department of Translational Neuroscience, UMCU Brain Center, University Medical Center Utrecht, Utrecht, Netherlands
| | - Dimphna H Meijer
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, Netherlands
| |
Collapse
|
9
|
Vural A, Doppler K, Meinl E. Autoantibodies Against the Node of Ranvier in Seropositive Chronic Inflammatory Demyelinating Polyneuropathy: Diagnostic, Pathogenic, and Therapeutic Relevance. Front Immunol 2018; 9:1029. [PMID: 29867996 PMCID: PMC5960694 DOI: 10.3389/fimmu.2018.01029] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 04/24/2018] [Indexed: 11/13/2022] Open
Abstract
Discovery of disease-associated autoantibodies has transformed the clinical management of a variety of neurological disorders. Detection of autoantibodies aids diagnosis and allows patient stratification resulting in treatment optimization. In the last years, a set of autoantibodies against proteins located at the node of Ranvier has been identified in patients with chronic inflammatory demyelinating polyneuropathy (CIDP). These antibodies target neurofascin, contactin1, or contactin-associated protein 1, and we propose to name CIDP patients with these antibodies collectively as seropositive. They have unique clinical characteristics that differ from seronegative CIDP. Moreover, there is compelling evidence that autoantibodies are relevant for the pathogenesis. In this article, we review the current knowledge on the characteristics of autoantibodies against the node of Ranvier proteins and their clinical relevance in CIDP. We start with a description of the structure of the node of Ranvier followed by a summary of assays used to identify seropositive patients; and then, we describe clinical features and characteristics linked to seropositivity. We review knowledge on the role of these autoantibodies for the pathogenesis with relevance for the emerging concept of nodopathy/paranodopathy and summarize the treatment implications.
Collapse
Affiliation(s)
- Atay Vural
- Institute of Clinical Neuroimmunology, Biomedical Center, University Hospitals, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany.,Research Center for Translational Medicine, Koç University, Istanbul, Turkey
| | - Kathrin Doppler
- Department of Neurology, University Hospital Würzburg, Würzburg, Germany
| | - Edgar Meinl
- Institute of Clinical Neuroimmunology, Biomedical Center, University Hospitals, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
| |
Collapse
|
10
|
Bang ML, Vainshtein A, Yang HJ, Eshed-Eisenbach Y, Devaux J, Werner HB, Peles E. Glial M6B stabilizes the axonal membrane at peripheral nodes of Ranvier. Glia 2018; 66:801-812. [PMID: 29282769 PMCID: PMC5812800 DOI: 10.1002/glia.23285] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 12/06/2017] [Accepted: 12/11/2017] [Indexed: 12/18/2022]
Abstract
Glycoprotein M6B and the closely related proteolipid protein regulate oligodendrocyte myelination in the central nervous system, but their role in the peripheral nervous system is less clear. Here we report that M6B is located at nodes of Ranvier in peripheral nerves where it stabilizes the nodal axolemma. We show that M6B is co-localized and associates with gliomedin at Schwann cell microvilli that are attached to the nodes. Developmental analysis of sciatic nerves, as well as of myelinating Schwann cells/dorsal root ganglion neurons cultures, revealed that M6B is already present at heminodes, which are considered the precursors of mature nodes of Ranvier. However, in contrast to gliomedin, which accumulates at heminodes with or prior to Na+ channels, we often detected Na+ channel clusters at heminodes without any associated M6B, indicating that it is not required for initial channel clustering. Consistently, nodal cell adhesion molecules (NF186, NrCAM), ion channels (Nav1.2 and Kv7.2), cytoskeletal proteins (AnkG and βIV spectrin), and microvilli components (pERM, syndecan3, gliomedin), are all present at both heminodes and mature nodes of Ranvier in Gpm6b null mice. Using transmission electron microscopy, we show that the absence of M6B results in progressive appearance of nodal protrusions of the nodal axolemma, that are often accompanied by the presence of enlarged mitochondria. Our results reveal that M6B is a Schwann cell microvilli component that preserves the structural integrity of peripheral nodes of Ranvier.
Collapse
Affiliation(s)
- Marie L Bang
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Anya Vainshtein
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Hyun-Jeong Yang
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Yael Eshed-Eisenbach
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Jerome Devaux
- Aix-Marseille University, CNRS, CRN2M-UMR 7286, Marseille, France
| | - Hauke B Werner
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Goettingen, Germany
| | - Elior Peles
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| |
Collapse
|
11
|
Pinatel D, Hivert B, Saint-Martin M, Noraz N, Savvaki M, Karagogeos D, Faivre-Sarrailh C. The Kv1-associated molecules TAG-1 and Caspr2 are selectively targeted to the axon initial segment in hippocampal neurons. J Cell Sci 2017; 130:2209-2220. [PMID: 28533267 DOI: 10.1242/jcs.202267] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Accepted: 05/18/2017] [Indexed: 12/28/2022] Open
Abstract
Caspr2 and TAG-1 (also known as CNTNAP2 and CNTN2, respectively) are cell adhesion molecules (CAMs) associated with the voltage-gated potassium channels Kv1.1 and Kv1.2 (also known as KCNA1 and KCNA2, respectively) at regions controlling axonal excitability, namely, the axon initial segment (AIS) and juxtaparanodes of myelinated axons. The distribution of Kv1 at juxtaparanodes requires axo-glial contacts mediated by Caspr2 and TAG-1. In the present study, we found that TAG-1 strongly colocalizes with Kv1.2 at the AIS of cultured hippocampal neurons, whereas Caspr2 is uniformly expressed along the axolemma. Live-cell imaging revealed that Caspr2 and TAG-1 are sorted together in axonal transport vesicles. Therefore, their differential distribution may result from diffusion and trapping mechanisms induced by selective partnerships. By using deletion constructs, we identified two molecular determinants of Caspr2 that regulate its axonal positioning. First, the LNG2-EGF1 modules in the ectodomain of Caspr2, which are involved in its axonal distribution. Deletion of these modules promotes AIS localization and association with TAG-1. Second, the cytoplasmic PDZ-binding site of Caspr2, which could elicit AIS enrichment and recruitment of the membrane-associated guanylate kinase (MAGuK) protein MPP2. Hence, the selective distribution of Caspr2 and TAG-1 may be regulated, allowing them to modulate the strategic function of the Kv1 complex along axons.
Collapse
Affiliation(s)
- Delphine Pinatel
- Aix-Marseille Université, CNRS, Centre de Recherche en Neurobiologie et Neurophysiologie de Marseille, UMR7286, Marseille, France
| | - Bruno Hivert
- Aix-Marseille Université, CNRS, Centre de Recherche en Neurobiologie et Neurophysiologie de Marseille, UMR7286, Marseille, France
| | - Margaux Saint-Martin
- Institut Neuromyogène, CNRS UMR 5310, INSERM U1217, Université Claude Bernard Lyon 1, Lyon, France
| | - Nelly Noraz
- Institut Neuromyogène, CNRS UMR 5310, INSERM U1217, Université Claude Bernard Lyon 1, Lyon, France
| | - Maria Savvaki
- Department of Basic Sciences, University of Crete Medical School and Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology, University of Crete, Heraklion, Greece
| | - Domna Karagogeos
- Department of Basic Sciences, University of Crete Medical School and Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology, University of Crete, Heraklion, Greece
| | - Catherine Faivre-Sarrailh
- Aix-Marseille Université, CNRS, Centre de Recherche en Neurobiologie et Neurophysiologie de Marseille, UMR7286, Marseille, France
| |
Collapse
|
12
|
Maluenda J, Manso C, Quevarec L, Vivanti A, Marguet F, Gonzales M, Guimiot F, Petit F, Toutain A, Whalen S, Grigorescu R, Coeslier AD, Gut M, Gut I, Laquerrière A, Devaux J, Melki J. Mutations in GLDN, Encoding Gliomedin, a Critical Component of the Nodes of Ranvier, Are Responsible for Lethal Arthrogryposis. Am J Hum Genet 2016; 99:928-933. [PMID: 27616481 DOI: 10.1016/j.ajhg.2016.07.021] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Accepted: 07/29/2016] [Indexed: 12/25/2022] Open
Abstract
Arthrogryposis multiplex congenita (AMC) is a developmental condition characterized by multiple joint contractures resulting from reduced or absent fetal movements. Through linkage analysis, homozygosity mapping, and exome sequencing in four unrelated families affected by lethal AMC, we identified biallelic mutations in GLDN in the affected individuals. GLDN encodes gliomedin, a secreted cell adhesion molecule involved in the formation of the nodes of Ranvier. Transmission electron microscopy of the sciatic nerve from one of the affected individuals showed a marked lengthening defect of the nodes. The GLDN mutations found in the affected individuals abolish the cell surface localization of gliomedin and its interaction with its axonal partner, neurofascin-186 (NF186), in a cell-based assay. The axoglial contact between gliomedin and NF186 is essential for the initial clustering of Na+ channels at developing nodes. These results indicate a major role of gliomedin in node formation and the development of the peripheral nervous system in humans. These data indicate that mutations of GLDN or CNTNAP1 (MIM: 616286), encoding essential components of the nodes of Ranvier and paranodes, respectively, lead to inherited nodopathies, a distinct disease entity among peripheral neuropathies.
Collapse
Affiliation(s)
- Jérôme Maluenda
- INSERM UMR-1169, Université Paris Saclay, Le Kremlin Bicêtre 94276, France
| | - Constance Manso
- UMR-7286, Centre de Recherche en Neurobiologie et Neurophysiologie de Marseille, Aix-Marseille Université, Centre National de la Recherche Scientifique, Marseille 13444, France
| | - Loic Quevarec
- INSERM UMR-1169, Université Paris Saclay, Le Kremlin Bicêtre 94276, France
| | - Alexandre Vivanti
- INSERM UMR-1169, Université Paris Saclay, Le Kremlin Bicêtre 94276, France
| | - Florent Marguet
- Pathology Laboratory, Rouen University Hospital, Rouen 76000, France; INSERM, NéoVasc Laboratory, University of Rouen, Rouen 76000, France
| | - Marie Gonzales
- Département de Génétique Médicale, Hôpital Trousseau and Université Pierre et Marie Curie, Paris 75571, France
| | - Fabien Guimiot
- INSERM U-1141, Service de Biologie du Développement, Hôpital Robert Debré, Paris 75019, France
| | - Florence Petit
- Clinique de Génétique Guy Fontaine, Hôpital Jeanne de Flandre, Centre Hospitalier Régional Universitaire, Lille 59037, France
| | - Annick Toutain
- Service de Génétique, Hôpital Bretonneau, Centre Hospitalier Universitaire de Tours, Tours 37044, France
| | - Sandra Whalen
- Département de Génétique Médicale, Hôpital Trousseau and Université Pierre et Marie Curie, Paris 75571, France
| | - Romulus Grigorescu
- Département de Génétique Médicale, Hôpital Trousseau and Université Pierre et Marie Curie, Paris 75571, France
| | - Anne Dieux Coeslier
- Clinique de Génétique Guy Fontaine, Hôpital Jeanne de Flandre, Centre Hospitalier Régional Universitaire, Lille 59037, France
| | - Marta Gut
- CNAG-CRG, Barcelona Institute of Science and Technology, Universitat Pompeu Fabra, Baldiri i Reixac 4, Barcelona 08028, Spain
| | - Ivo Gut
- CNAG-CRG, Barcelona Institute of Science and Technology, Universitat Pompeu Fabra, Baldiri i Reixac 4, Barcelona 08028, Spain
| | - Annie Laquerrière
- Pathology Laboratory, Rouen University Hospital, Rouen 76000, France; INSERM, NéoVasc Laboratory, University of Rouen, Rouen 76000, France
| | - Jérôme Devaux
- UMR-7286, Centre de Recherche en Neurobiologie et Neurophysiologie de Marseille, Aix-Marseille Université, Centre National de la Recherche Scientifique, Marseille 13444, France
| | - Judith Melki
- INSERM UMR-1169, Université Paris Saclay, Le Kremlin Bicêtre 94276, France.
| |
Collapse
|
13
|
Dixit AB, Banerjee J, Srivastava A, Tripathi M, Sarkar C, Kakkar A, Jain M, Chandra PS. RNA-seq analysis of hippocampal tissues reveals novel candidate genes for drug refractory epilepsy in patients with MTLE-HS. Genomics 2016; 107:178-88. [DOI: 10.1016/j.ygeno.2016.04.001] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Revised: 01/12/2016] [Accepted: 04/05/2016] [Indexed: 12/13/2022]
|
14
|
Hivert B, Pinatel D, Labasque M, Tricaud N, Goutebroze L, Faivre-Sarrailh C. Assembly of juxtaparanodes in myelinating DRG culture: Differential clustering of the Kv1/Caspr2 complex and scaffolding protein 4.1B. Glia 2016; 64:840-52. [PMID: 26840208 DOI: 10.1002/glia.22968] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 01/04/2016] [Accepted: 01/06/2016] [Indexed: 11/06/2022]
Abstract
The precise distribution of ion channels at the nodes of Ranvier is essential for the efficient propagation of action potentials along myelinated axons. The voltage-gated potassium channels Kv1.1/1.2 are clustered at the juxtaparanodes in association with the cell adhesion molecules, Caspr2 and TAG-1 and the scaffolding protein 4.1B. In the present study, we set up myelinating cultures of DRG neurons and Schwann cells to look through the formation of juxtaparanodes in vitro. We showed that the Kv1.1/Kv1.2 channels were first enriched at paranodes before being restricted to distal paranodes and juxtaparanodes. In addition, the Kv1 channels displayed an asymmetric expression enriched at the distal juxtaparanodes. Caspr2 was strongly co-localized with Kv1.2 whereas the scaffolding protein 4.1B was preferentially recruited at paranodes while being present at juxtaparanodes too. Kv1.2/Caspr2 but not 4.1B, also transiently accumulated within the nodal region both in myelinated cultures and developing sciatic nerves. Studying cultures and sciatic nerves from 4.1B KO mice, we further showed that 4.1B is required for the proper targeting of Caspr2 early during myelination. Moreover, using adenoviral-mediated expression of Caspr-GFP and photobleaching experiments, we analyzed the stability of paranodal junctions and showed that the lateral stability of paranodal Caspr was not altered in 4.1B KO mice indicating that 4.1B is not required for the assembly and stability of the paranodal junctions. Thus, developing an adapted culture paradigm, we provide new insights into the dynamic and differential distribution of Kv1 channels and associated proteins during myelination.
Collapse
Affiliation(s)
- Bruno Hivert
- Aix-Marseille Université, CNRS, Centre de Recherche en Neurobiologie et Neurophysiologie de Marseille-UMR7286, Marseille, France
| | - Delphine Pinatel
- Aix-Marseille Université, CNRS, Centre de Recherche en Neurobiologie et Neurophysiologie de Marseille-UMR7286, Marseille, France
| | - Marilyne Labasque
- Aix-Marseille Université, CNRS, Centre de Recherche en Neurobiologie et Neurophysiologie de Marseille-UMR7286, Marseille, France
| | - Nicolas Tricaud
- INSERM U1051 Institut des Neurosciences de Montpellier, Montpellier, France
| | | | - Catherine Faivre-Sarrailh
- Aix-Marseille Université, CNRS, Centre de Recherche en Neurobiologie et Neurophysiologie de Marseille-UMR7286, Marseille, France
| |
Collapse
|
15
|
Freeman SA, Desmazières A, Fricker D, Lubetzki C, Sol-Foulon N. Mechanisms of sodium channel clustering and its influence on axonal impulse conduction. Cell Mol Life Sci 2016; 73:723-35. [PMID: 26514731 PMCID: PMC4735253 DOI: 10.1007/s00018-015-2081-1] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 10/21/2015] [Accepted: 10/22/2015] [Indexed: 12/16/2022]
Abstract
The efficient propagation of action potentials along nervous fibers is necessary for animals to interact with the environment with timeliness and precision. Myelination of axons is an essential step to ensure fast action potential propagation by saltatory conduction, a process that requires highly concentrated voltage-gated sodium channels at the nodes of Ranvier. Recent studies suggest that the clustering of sodium channels can influence axonal impulse conduction in both myelinated and unmyelinated fibers, which could have major implications in disease, particularly demyelinating pathology. This comprehensive review summarizes the mechanisms governing the clustering of sodium channels at the peripheral and central nervous system nodes and the specific roles of their clustering in influencing action potential conduction. We further highlight the classical biophysical parameters implicated in conduction timing, followed by a detailed discussion on how sodium channel clustering along unmyelinated axons can impact axonal impulse conduction in both physiological and pathological contexts.
Collapse
Affiliation(s)
- Sean A Freeman
- ICM-GHU Pitié-Salpêtrière, Sorbonne Universités UPMC Univ Paris 06, UMR_S 1127, 75013, Paris, France.
- Inserm U1127, 75013, Paris, France.
- CNRS UMR7225, 75013, Paris, France.
| | - Anne Desmazières
- ICM-GHU Pitié-Salpêtrière, Sorbonne Universités UPMC Univ Paris 06, UMR_S 1127, 75013, Paris, France.
- Inserm U1127, 75013, Paris, France.
- CNRS UMR7225, 75013, Paris, France.
| | - Desdemona Fricker
- ICM-GHU Pitié-Salpêtrière, Sorbonne Universités UPMC Univ Paris 06, UMR_S 1127, 75013, Paris, France.
- Inserm U1127, 75013, Paris, France.
- CNRS UMR7225, 75013, Paris, France.
| | - Catherine Lubetzki
- ICM-GHU Pitié-Salpêtrière, Sorbonne Universités UPMC Univ Paris 06, UMR_S 1127, 75013, Paris, France.
- Inserm U1127, 75013, Paris, France.
- CNRS UMR7225, 75013, Paris, France.
- Assistance Publique-Hôpitaux de Paris, Hôpital Pitié-Salpêtrière, Paris, France.
| | - Nathalie Sol-Foulon
- ICM-GHU Pitié-Salpêtrière, Sorbonne Universités UPMC Univ Paris 06, UMR_S 1127, 75013, Paris, France.
- Inserm U1127, 75013, Paris, France.
- CNRS UMR7225, 75013, Paris, France.
| |
Collapse
|
16
|
Rasband MN, Peles E. The Nodes of Ranvier: Molecular Assembly and Maintenance. Cold Spring Harb Perspect Biol 2015; 8:a020495. [PMID: 26354894 DOI: 10.1101/cshperspect.a020495] [Citation(s) in RCA: 121] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Action potential (AP) propagation in myelinated nerves requires clustered voltage gated sodium and potassium channels. These channels must be specifically localized to nodes of Ranvier where the AP is regenerated. Several mechanisms have evolved to facilitate and ensure the correct assembly and stabilization of these essential axonal domains. This review highlights the current understanding of the axon intrinsic and glial extrinsic mechanisms that control the formation and maintenance of the nodes of Ranvier in both the peripheral nervous system (PNS) and central nervous system (CNS).
Collapse
Affiliation(s)
- Matthew N Rasband
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030
| | - Elior Peles
- Department of Molecular Cell Biology, The Weizmann Institute of Science, Rehovot 76100, Israel
| |
Collapse
|
17
|
Pinatel D, Hivert B, Boucraut J, Saint-Martin M, Rogemond V, Zoupi L, Karagogeos D, Honnorat J, Faivre-Sarrailh C. Inhibitory axons are targeted in hippocampal cell culture by anti-Caspr2 autoantibodies associated with limbic encephalitis. Front Cell Neurosci 2015. [PMID: 26217189 PMCID: PMC4496579 DOI: 10.3389/fncel.2015.00265] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Contactin-associated protein-like 2 (Caspr2), also known as CNTNAP2, is a cell adhesion molecule that clusters voltage-gated potassium channels (Kv1.1/1.2) at the juxtaparanodes of myelinated axons and may regulate axonal excitability. As a component of the Kv1 complex, Caspr2 has been identified as a target in neuromyotonia and Morvan syndrome, but also in some cases of autoimmune limbic encephalitis (LE). How anti-Caspr2 autoimmunity is linked with the central neurological symptoms is still elusive. In the present study, using anti-Caspr2 antibodies from seven patients affected by pure LE, we determined that IgGs in the cerebrospinal fluid of four out seven patients were selectively directed against the N-terminal Discoïdin and LamininG1 modules of Caspr2. Using live immunolabeling of cultured hippocampal neurons, we determined that serum IgGs in all patients strongly targeted inhibitory interneurons. Caspr2 was highly detected on GAD65-positive axons that are surrounding the cell bodies and at the VGAT-positive inhibitory presynaptic contacts. Functional assays indicated that LE autoantibodies may induce alteration of Gephyrin clusters at inhibitory synaptic contacts. Next, we generated a Caspr2-Fc chimera to reveal Caspr2 receptors on hippocampal neurons localized at the somato-dendritic compartment and post-synapse. Caspr2-Fc binding was strongly increased on TAG-1-transfected neurons and conversely, Caspr2-Fc did not bind hippocampal neurons from TAG-1-deficient mice. Our data indicate that Caspr2 may participate as a cell recognition molecule in the dynamics of inhibitory networks. This study provides new insight into the potential pathogenic effect of anti-Caspr2 autoantibodies in central hyperexcitability that may be related with perturbation of inhibitory interneuron activity.
Collapse
Affiliation(s)
- Delphine Pinatel
- Aix Marseille Université, CNRS, Centre de Recherche en Neurobiologie et Neurophysiologie de Marseille, CRN2M-UMR7286, Faculté de Médecine Nord Marseille, France
| | - Bruno Hivert
- Aix Marseille Université, CNRS, Centre de Recherche en Neurobiologie et Neurophysiologie de Marseille, CRN2M-UMR7286, Faculté de Médecine Nord Marseille, France
| | - José Boucraut
- Aix Marseille Université, CNRS, Centre de Recherche en Neurobiologie et Neurophysiologie de Marseille, CRN2M-UMR7286, Faculté de Médecine Nord Marseille, France ; Laboratoire d'Immunologie et d'Immunopathologie, AP-HM, Hôpital de la Conception Marseille, France
| | - Margaux Saint-Martin
- French Reference Center on Paraneoplastic Neurological Syndrome, Hospices Civils de Lyon, Hôpital Neurologique Bron, France ; INSERM U1028 - CNRS UMR 5292, Lyon Neuroscience Research Center Lyon, France ; Université de Lyon - Université Claude Bernard Lyon 1 Lyon, France
| | - Véronique Rogemond
- French Reference Center on Paraneoplastic Neurological Syndrome, Hospices Civils de Lyon, Hôpital Neurologique Bron, France ; INSERM U1028 - CNRS UMR 5292, Lyon Neuroscience Research Center Lyon, France ; Université de Lyon - Université Claude Bernard Lyon 1 Lyon, France
| | - Lida Zoupi
- Institute of Molecular Biology and Biotechnology - Foundation for Research and Technology, University of Crete Heraklion, Greece
| | - Domna Karagogeos
- Institute of Molecular Biology and Biotechnology - Foundation for Research and Technology, University of Crete Heraklion, Greece
| | - Jérôme Honnorat
- French Reference Center on Paraneoplastic Neurological Syndrome, Hospices Civils de Lyon, Hôpital Neurologique Bron, France ; INSERM U1028 - CNRS UMR 5292, Lyon Neuroscience Research Center Lyon, France ; Université de Lyon - Université Claude Bernard Lyon 1 Lyon, France
| | - Catherine Faivre-Sarrailh
- Aix Marseille Université, CNRS, Centre de Recherche en Neurobiologie et Neurophysiologie de Marseille, CRN2M-UMR7286, Faculté de Médecine Nord Marseille, France
| |
Collapse
|
18
|
Hill SE, Donegan RK, Nguyen E, Desai TM, Lieberman RL. Molecular Details of Olfactomedin Domains Provide Pathway to Structure-Function Studies. PLoS One 2015; 10:e0130888. [PMID: 26121352 PMCID: PMC4488277 DOI: 10.1371/journal.pone.0130888] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 05/26/2015] [Indexed: 11/18/2022] Open
Abstract
Olfactomedin (OLF) domains are found within extracellular, multidomain proteins in numerous tissues of multicellular organisms. Even though these proteins have been implicated in human disorders ranging from cancers to attention deficit disorder to glaucoma, little is known about their structure(s) and function(s). Here we biophysically, biochemically, and structurally characterize OLF domains from H. sapiens olfactomedin-1 (npoh-OLF, also called noelin, pancortin, OLFM1, and hOlfA), and M. musculus gliomedin (glio-OLF, also called collomin, collmin, and CRG-L2), and compare them with available structures of myocilin (myoc-OLF) recently reported by us and R. norvegicus glio-OLF and M. musculus latrophilin-3 (lat3-OLF) by others. Although the five-bladed β-propeller architecture remains unchanged, numerous physicochemical characteristics differ among these OLF domains. First, npoh-OLF and glio-OLF exhibit prominent, yet distinct, positive surface charges and copurify with polynucleotides. Second, whereas npoh-OLF and myoc-OLF exhibit thermal stabilities typical of human proteins near 55°C, and most myoc-OLF variants are destabilized and highly prone to aggregation, glio-OLF is nearly 20°C more stable and significantly more resistant to chemical denaturation. Phylogenetically, glio-OLF is most similar to primitive OLFs, and structurally, glio-OLF is missing distinguishing features seen in OLFs such as the disulfide bond formed by N- and C- terminal cysteines, the sequestered Ca2+ ion within the propeller central hydrophilic cavity, and a key loop-stabilizing cation-π interaction on the top face of npoh-OLF and myoc-OLF. While deciphering the explicit biological functions, ligands, and binding partners for OLF domains will likely continue to be a challenging long-term experimental pursuit, we used structural insights gained here to generate a new antibody selective for myoc-OLF over npoh-OLF and glio-OLF as a first step in overcoming the impasse in detailed functional characterization of these biomedically important protein domains.
Collapse
Affiliation(s)
- Shannon E. Hill
- School of Chemistry & Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Rebecca K. Donegan
- School of Chemistry & Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Elaine Nguyen
- School of Chemistry & Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Tanay M. Desai
- School of Chemistry & Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Raquel L. Lieberman
- School of Chemistry & Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, United States of America
- * E-mail:
| |
Collapse
|
19
|
Huijbers MG, Querol LA, Niks EH, Plomp JJ, van der Maarel SM, Graus F, Dalmau J, Illa I, Verschuuren JJ. The expanding field of IgG4-mediated neurological autoimmune disorders. Eur J Neurol 2015; 22:1151-61. [PMID: 26032110 DOI: 10.1111/ene.12758] [Citation(s) in RCA: 122] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Accepted: 04/27/2015] [Indexed: 12/13/2022]
Abstract
At least 13 different disease entities affecting the central nervous system, peripheral nervous system and connective tissue of the skin or kidneys are associated with immunoglobulin G4 (IgG4) immune reactivity. IgG4 has always been considered a benign, non-inflammatory subclass of IgG, in contrast to the well-known complement-activating pro-inflammatory IgG1 subclass. A comprehensive review of these IgG4 autoimmune disorders reveals striking similarities in epitope binding and human leukocyte antigen (HLA) associations. Mechanical interference of extracellular ligand-receptor interactions by the associated IgG4 antibodies seems to be the common/converging disease mechanism in these disorders.
Collapse
Affiliation(s)
- M G Huijbers
- Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands.,Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - L A Querol
- Department of Neurology, Hospital Santa Creu I Sant Pau, Barcelona, Spain
| | - E H Niks
- Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands
| | - J J Plomp
- Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands
| | - S M van der Maarel
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - F Graus
- Department of Neurology, Hospital Santa Creu I Sant Pau, Barcelona, Spain
| | - J Dalmau
- Department of Neurology, Hospital Santa Creu I Sant Pau, Barcelona, Spain
| | - I Illa
- Department of Neurology, Hospital Santa Creu I Sant Pau, Barcelona, Spain
| | - J J Verschuuren
- Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands
| |
Collapse
|
20
|
Colombelli C, Palmisano M, Eshed-Eisenbach Y, Zambroni D, Pavoni E, Ferri C, Saccucci S, Nicole S, Soininen R, McKee KK, Yurchenco PD, Peles E, Wrabetz L, Feltri ML. Perlecan is recruited by dystroglycan to nodes of Ranvier and binds the clustering molecule gliomedin. J Cell Biol 2015; 208:313-29. [PMID: 25646087 PMCID: PMC4315246 DOI: 10.1083/jcb.201403111] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Accepted: 12/18/2014] [Indexed: 01/09/2023] Open
Abstract
Fast neural conduction requires accumulation of Na(+) channels at nodes of Ranvier. Dedicated adhesion molecules on myelinating cells and axons govern node organization. Among those, specific laminins and dystroglycan complexes contribute to Na(+) channel clustering at peripheral nodes by unknown mechanisms. We show that in addition to facing the basal lamina, dystroglycan is found near the nodal matrix around axons, binds matrix components, and participates in initial events of nodogenesis. We identify the dystroglycan-ligand perlecan as a novel nodal component and show that dystroglycan is required for the selective accumulation of perlecan at nodes. Perlecan binds the clustering molecule gliomedin and enhances clustering of node of Ranvier components. These data show that proteoglycans have specific roles in peripheral nodes and indicate that peripheral and central axons use similar strategies but different molecules to form nodes of Ranvier. Further, our data indicate that dystroglycan binds free matrix that is not organized in a basal lamina.
Collapse
Affiliation(s)
- Cristina Colombelli
- Division of Genetics and Cell Biology, San Raffaele Hospital, 20132 Milan, Italy
| | - Marilena Palmisano
- Division of Genetics and Cell Biology, San Raffaele Hospital, 20132 Milan, Italy Department of Biochemistry and Department of Neurology, Hunter James Kelly Research Institute, School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY 14203 Department of Biochemistry and Department of Neurology, Hunter James Kelly Research Institute, School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY 14203
| | - Yael Eshed-Eisenbach
- Department of Molecular Cell Biology, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Desirée Zambroni
- Division of Genetics and Cell Biology, San Raffaele Hospital, 20132 Milan, Italy
| | - Ernesto Pavoni
- Division of Genetics and Cell Biology, San Raffaele Hospital, 20132 Milan, Italy
| | - Cinzia Ferri
- Division of Genetics and Cell Biology, San Raffaele Hospital, 20132 Milan, Italy
| | - Stefania Saccucci
- Division of Genetics and Cell Biology, San Raffaele Hospital, 20132 Milan, Italy
| | - Sophie Nicole
- Institut du Cerveau et de la Moelle Épinière, 75013 Paris, France Institut National de la Santé et de la Recherche Médicale, U1127, 75019 Paris, France Sorbonne Universités, Université Pierre et Marie Currie, UMRS1127, 75252 Paris, France Centre National de la Recherche Scientifique, UMR 7225, 75013 Paris, France
| | - Raija Soininen
- Oulu Center for Cell-Extracellular Matrix Research, University of Oulu, 90014 Oulu, Finland
| | | | | | - Elior Peles
- Department of Molecular Cell Biology, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Lawrence Wrabetz
- Division of Genetics and Cell Biology, San Raffaele Hospital, 20132 Milan, Italy Department of Biochemistry and Department of Neurology, Hunter James Kelly Research Institute, School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY 14203 Department of Biochemistry and Department of Neurology, Hunter James Kelly Research Institute, School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY 14203
| | - M Laura Feltri
- Division of Genetics and Cell Biology, San Raffaele Hospital, 20132 Milan, Italy Department of Biochemistry and Department of Neurology, Hunter James Kelly Research Institute, School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY 14203 Department of Biochemistry and Department of Neurology, Hunter James Kelly Research Institute, School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY 14203
| |
Collapse
|
21
|
Han H, Kursula P. The olfactomedin domain from gliomedin is a β-propeller with unique structural properties. J Biol Chem 2014; 290:3612-21. [PMID: 25525261 DOI: 10.1074/jbc.m114.627547] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
All members of the olfactomedin (OLF) family have a conserved extracellular OLF domain, for which a structure has not been available. We present here the crystal structure of the OLF domain from gliomedin. Gliomedin is a protein expressed by Schwann cells in peripheral nerves, important for the formation of the nodes of Ranvier. Gliomedin interacts with neuronal cell adhesion molecules, such as neurofascin, but the structural details of the interaction are not known. The structure of the OLF domain presents a five-bladed β-propeller fold with unusual geometric properties. The symmetry of the structure is not 5-fold, but rather reveals a twisted arrangement. The conserved top face of the gliomedin OLF domain is likely to be important for binding to neuronal ligands. Our results provide a structural basis for the functions of gliomedin in Schwann cells, enable the understanding of the role of the gliomedin OLF domain in autoimmune neuropathies, and unravel the locations of human disease-causing mutations in other OLF family members, including myocilin.
Collapse
Affiliation(s)
- Huijong Han
- From the Faculty of Biochemistry and Molecular Medicine and Biocenter Oulu, University of Oulu, 90014 Oulu, Finland, the German Electron Synchrotron (DESY), 22607 Hamburg, Germany, and
| | - Petri Kursula
- From the Faculty of Biochemistry and Molecular Medicine and Biocenter Oulu, University of Oulu, 90014 Oulu, Finland, the German Electron Synchrotron (DESY), 22607 Hamburg, Germany, and the Department of Biomedicine, University of Bergen, N-5020 Bergen, Norway
| |
Collapse
|
22
|
Han H, Kursula P. Expression, purification, crystallization and preliminary X-ray crystallographic analysis of the extracellular olfactomedin domain of gliomedin. ACTA CRYSTALLOGRAPHICA SECTION F-STRUCTURAL BIOLOGY COMMUNICATIONS 2014; 70:1536-9. [PMID: 25372825 DOI: 10.1107/s2053230x14020305] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Accepted: 09/09/2014] [Indexed: 11/10/2022]
Abstract
Gliomedin (GLDN) is one of the essential proteins in the development of the nodes of Ranvier in the vertebrate peripheral nervous system. An olfactomedin (OLF) domain is located at the GLDN extracellular C-terminus and is involved in the accumulation of neuronal plasma membrane voltage-gated sodium channels in the nodes by interacting with neurofascin and NrCAM. No structures of OLF domains have previously been reported. Here, the crystallization of the rat GLDN OLF domain, which was expressed in an insect-cell system, is reported. The crystal diffracted to 1.55 Å resolution and belonged to space group P2₁, with unit-cell parameters a=37.5, b=141.7, c=46.0 Å, β=110.6°, and had two molecules in the asymmetric unit.
Collapse
Affiliation(s)
- Huijong Han
- Faculty of Biochemistry and Molecular Medicine and Biocenter Oulu, University of Oulu, PO Box 3000, FIN-90014 Oulu, Finland
| | - Petri Kursula
- Faculty of Biochemistry and Molecular Medicine and Biocenter Oulu, University of Oulu, PO Box 3000, FIN-90014 Oulu, Finland
| |
Collapse
|
23
|
Amor V, Feinberg K, Eshed-Eisenbach Y, Vainshtein A, Frechter S, Grumet M, Rosenbluth J, Peles E. Long-term maintenance of Na+ channels at nodes of Ranvier depends on glial contact mediated by gliomedin and NrCAM. J Neurosci 2014; 34:5089-98. [PMID: 24719088 PMCID: PMC3983794 DOI: 10.1523/jneurosci.4752-13.2014] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Clustering of Na(+) channels at the nodes of Ranvier is coordinated by myelinating glia. In the peripheral nervous system, axoglial contact at the nodes is mediated by the binding of gliomedin and glial NrCAM to axonal neurofascin 186 (NF186). This interaction is crucial for the initial clustering of Na(+) channels at heminodes. As a result, it is not clear whether continued axon-glial contact at nodes of Ranvier is required to maintain these channels at the nodal axolemma. Here, we report that, in contrast to mice that lack either gliomedin or NrCAM, absence of both molecules (and hence the glial clustering signal) resulted in a gradual loss of Na(+) channels and other axonal components from the nodes, the formation of binary nodes, and dysregulation of nodal gap length. Therefore, these mice exhibit neurological abnormalities and slower nerve conduction. Disintegration of the nodes occurred in an orderly manner, starting with the disappearance of neurofascin 186, followed by the loss of Na(+) channels and ankyrin G, and then βIV spectrin, a sequence that reflects the assembly of nodes during development. Finally, the absence of gliomedin and NrCAM led to the invasion of the outermost layer of the Schwann cell membrane beyond the nodal area and the formation of paranodal-like junctions at the nodal gap. Our results reveal that axon-glial contact mediated by gliomedin, NrCAM, and NF186 not only plays a role in Na(+) channel clustering during development, but also contributes to the long-term maintenance of Na(+) channels at nodes of Ranvier.
Collapse
Affiliation(s)
- Veronique Amor
- 1Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 76100, Israel;
| | - Konstantin Feinberg
- 1Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 76100, Israel;
| | - Yael Eshed-Eisenbach
- 1Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 76100, Israel;
| | - Anya Vainshtein
- 1Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 76100, Israel;
| | - Shahar Frechter
- 1Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 76100, Israel;
| | - Martin Grumet
- 2 W.M. Keck Center for Collaborative Neuroscience, Rutgers University, Piscataway, New Jersey 08854; and
| | - Jack Rosenbluth
- 3Department of Neuroscience and Physiology, New York University School of Medicine, New York, New York 10016
| | - Elior Peles
- 1Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 76100, Israel;
| |
Collapse
|
24
|
Anholt RRH. Olfactomedin proteins: central players in development and disease. Front Cell Dev Biol 2014; 2:6. [PMID: 25364714 PMCID: PMC4206993 DOI: 10.3389/fcell.2014.00006] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Accepted: 02/07/2014] [Indexed: 12/14/2022] Open
Abstract
Olfactomedin proteins are characterized by a conserved domain of \texorpdfstring~\textasciitilde250 amino acids corresponding to the olfactomedin archetype first discovered in olfactory neuroepithelium. They arose early in evolution and occur throughout the animal kingdom. In mice and humans olfactomedin proteins comprise a diverse array of glycoproteins, many of which are critical for early development and functional organization of the nervous system as well as hematopoiesis. Olfactomedin domains appear to facilitate protein-protein interactions, intercellular interactions, and cell adhesion. Several members of the family have been implicated in various common diseases, notably myocilin in glaucoma and OLFM4 in cancer. This review highlights this important, hitherto understudied family of proteins.
Collapse
Affiliation(s)
- Robert R H Anholt
- Department of Biological Sciences and W. M. Keck Center for Behavioral Biology, North Carolina State University Raleigh, NC, USA
| |
Collapse
|
25
|
Querol L, Nogales-Gadea G, Rojas-Garcia R, Diaz-Manera J, Pardo J, Ortega-Moreno A, Sedano MJ, Gallardo E, Berciano J, Blesa R, Dalmau J, Illa I. Neurofascin IgG4 antibodies in CIDP associate with disabling tremor and poor response to IVIg. Neurology 2014; 82:879-86. [PMID: 24523485 DOI: 10.1212/wnl.0000000000000205] [Citation(s) in RCA: 230] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To describe the frequency of antibodies against neurofascin in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and the associated clinical features. METHODS Immunocytochemistry was used to identify antibodies to neurofascin 155 (NF155) and 186. Serum reactivity with paranodes and brain tissue was tested with immunohistochemistry of teased-nerve fibers and rat brain. Antibody titers and immunoglobulin (Ig) G isotypes were determined using ELISA. Clinical information was obtained retrospectively. RESULTS Two of 53 patients, but none of 204 controls, had antibodies to NF155 (p = 0.041). The 2 patients with NF155 antibodies developed severe polyradiculoneuropathy with predominant distal weakness that was refractory to IVIg. Eight additional patients with IVIg-refractory CIDP were then identified from a national database; 2 of them with the same clinical features also had NF155 antibodies. Overall, 3 of the 4 patients with NF155 antibodies had a disabling and characteristic tremor (high amplitude, low frequency, postural, and intention). Patients' antibodies reacted with the paranodes in teased-nerve fibers and with the neuropil of rat cerebellum, brain, and brainstem. Anti-NF155 antibodies were predominantly of the IgG4 isotype in all patients. CONCLUSION Patients with CIDP positive for IgG4 NF155 antibodies constitute a specific subgroup with a severe phenotype, poor response to IVIg, and disabling tremor. Autoantibodies against paranodal structures associate with distinct clinical features in CIDP and their identification has diagnostic, prognostic, and therapeutic implications. CLASSIFICATION OF EVIDENCE This study provides Class IV evidence that autoantibodies to NF155 identify a CIDP subtype characterized by severe neuropathy, poor response to IVIg, and disabling tremor.
Collapse
Affiliation(s)
- Luis Querol
- From the Neuromuscular Diseases Unit (L.Q., G.N.-G., R.R.-G., J.D.-M., E.G., R.B., I.I.), Department of Neurology, Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona; Centro para la Investigación Biomédica en Red en Enfermedades Neurodegenerativas (L.Q., G.N.-G., R.R.-G., J.D.-M., M.J.S., E.G., J.B., I.I.), CIBERNED, Madrid; Department of Neurology (J.P.), Hospital Clínico de Santiago, Santiago de Compostela; Department of Neurology (A.O.-M.), Hospital Virgen de las Nieves, Granada; Department of Neurology (M.J.S., J.B.), University Hospital Marqués de Valdecilla (IFIMAV) and University of Cantabria; Department of Neurology (J.D.), Hospital Clinic, Universitat de Barcelona-Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona; and Institució Catalana de Recerca i Estudis Avançats (J.D.), Barcelona, Spain
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Labasque M, Hivert B, Nogales-Gadea G, Querol L, Illa I, Faivre-Sarrailh C. Specific contactin N-glycans are implicated in neurofascin binding and autoimmune targeting in peripheral neuropathies. J Biol Chem 2014; 289:7907-18. [PMID: 24497634 DOI: 10.1074/jbc.m113.528489] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Cell adhesion molecules (CAMs) play a crucial role in the formation of the nodes of Ranvier and in the rapid propagation of the nerve impulses along myelinated axons. These CAMs are the targets of autoimmunity in inflammatory neuropathies. We recently showed that a subgroup of patients with aggressive chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) shows autoantibodies to contactin (1). The complex of contactin·Caspr·neurofascin-155 (NF155) enables the formation of paranodal junctions, suggesting that antibody attack against paranodes may participate in the severity of CIDP. In the present study, we mapped the molecular determinants of contactin targeted by the autoantibodies. In three patients, immunoreactivity was directed against the Ig domains of contactin and was dependent on N-glycans. The serum of one patient was selectively directed against contactin bearing mannose-rich N-glycans. Strikingly, the oligomannose type sugars of contactin are required for association with its glial partner NF155 (2). To investigate precisely the role of contactin N-glycans, we have mutated each of the nine consensus N-glycosylation sites independently. We found that the mutation of three sites (N467Q/N473Q/N494Q) in Ig domain 5 of contactin prevented soluble NF155-Fc binding. In contrast, these mutations did not abolish cis-association with Caspr. Next, we showed that the cluster of N-glycosylation sites (Asn-467, Asn-473, and Asn-494) was required for immunoreactivity in one patient. Using cell aggregation assays, we showed that the IgGs from the four CIDP patients prevented adhesive interaction between contactin·Caspr and NF155. Importantly, we showed that the anti-contactin autoantibodies induced alteration of paranodal junctions in myelinated neuronal culture. These results strongly suggest that antibodies to CAMs may be pathogenic and induce demyelination via functional blocking activity.
Collapse
Affiliation(s)
- Marilyne Labasque
- From Aix-Marseille Université, CNRS, Centre de Recherche en Neurobiologie et Neurophysiologie de Marseille-UMR7286, 13344 Marseille, France
| | | | | | | | | | | |
Collapse
|
27
|
Faivre-Sarrailh C, Devaux JJ. Neuro-glial interactions at the nodes of Ranvier: implication in health and diseases. Front Cell Neurosci 2013; 7:196. [PMID: 24194699 PMCID: PMC3810605 DOI: 10.3389/fncel.2013.00196] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Accepted: 10/08/2013] [Indexed: 01/06/2023] Open
Abstract
Specific cell adhesion molecules (CAMs) are dedicated to the formation of axo-glial contacts at the nodes of Ranvier of myelinated axons. They play a central role in the organization and maintenance of the axonal domains: the node, paranode, and juxtaparanode. In particular, CAMs are essential for the accumulation of voltage-gated sodium channels at the nodal gap that ensures the rapid and saltatory propagation of the action potentials (APs). The mechanisms regulating node formation are distinct in the central and peripheral nervous systems, and recent studies have highlighted the relative contribution of paranodal junctions and nodal extracellular matrix. In addition, CAMs at the juxtaparanodal domains mediate the clustering of voltage-gated potassium channels which regulate the axonal excitability. In several human pathologies, the axo-glial contacts are altered leading to disruption of the nodes of Ranvier or mis-localization of the ion channels along the axons. Node alterations and the failure of APs to propagate correctly from nodes to nodes along the axons both contribute to the disabilities in demyelinating diseases. This article reviews the mechanisms regulating the association of the axo-glial complexes and the role of CAMs in inherited and acquired neurological diseases.
Collapse
|
28
|
Eshed-Eisenbach Y, Peles E. The making of a node: a co-production of neurons and glia. Curr Opin Neurobiol 2013; 23:1049-56. [PMID: 23831261 DOI: 10.1016/j.conb.2013.06.003] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Accepted: 06/11/2013] [Indexed: 01/24/2023]
Abstract
Nodes of Ranvier are specialized axonal domains formed in response to a glial signal. Recent research advances have revealed that both CNS and PNS nodes form by several overlapping molecular mechanisms. However, the precise nature of these mechanisms and the hierarchy existing between them is considerably different in CNS versus PNS nodes. Namely, the Schwann cells of the PNS, which directly contact the nodal axolemma, secrete proteins that cluster axonodal components at the edges of the growing myelin segment. In contrast, the formation of CNS nodes, which are not contacted by the myelinating glia, is surprisingly similar to the assembly of the axon initial segment and depends largely on axonal diffusion barriers.
Collapse
Affiliation(s)
- Yael Eshed-Eisenbach
- Department of Molecular Cell Biology, The Weizmann Institute of Science, Rehovot 76100, Israel
| | | |
Collapse
|
29
|
Lindner M, Ng JKM, Hochmeister S, Meinl E, Linington C. Neurofascin 186 specific autoantibodies induce axonal injury and exacerbate disease severity in experimental autoimmune encephalomyelitis. Exp Neurol 2013; 247:259-66. [PMID: 23688679 DOI: 10.1016/j.expneurol.2013.05.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 04/24/2013] [Accepted: 05/08/2013] [Indexed: 12/23/2022]
Abstract
Axonal injury is considered the major cause of chronic disability in multiple sclerosis (MS) patients, however the mechanisms behind remain still unclear. Recently, it was demonstrated that autoantibodies against Neurofascin, a cell adhesion molecule within the adult nervous system, can contribute to the development of axonal pathology in some patients. We compared the ability of the two different isoforms of Neurofascin, Nfasc155 and Nfasc186, to induce a pathogenic antibody response in the Dark Agouti (DA) rat. Animals were immunized with recombinant proteins prior to induction of experimental autoimmune encephalomyelitis (EAE) by adoptive transfer of activated MOG-specific T cells. Only Nfasc186 induced an axopathic autoantibody response in vivo, despite extensive cross reactivity between the two isoforms as shown by ELISA and flow cytometry. In this case, using transfected cell lines failed to differentiate between pathogenic and non-pathogenic responses. These findings have important implications with respect to the usage of cell based assays as an approach to detect pathologically relevant autoantibodies in clinical samples.
Collapse
Affiliation(s)
- Maren Lindner
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, UK.
| | | | | | | | | |
Collapse
|
30
|
Buttermore ED, Thaxton CL, Bhat MA. Organization and maintenance of molecular domains in myelinated axons. J Neurosci Res 2013; 91:603-22. [PMID: 23404451 DOI: 10.1002/jnr.23197] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Revised: 09/19/2012] [Accepted: 11/28/2012] [Indexed: 01/17/2023]
Abstract
Over a century ago, Ramon y Cajal first proposed the idea of a directionality involved in nerve conduction and neuronal communication. Decades later, it was discovered that myelin, produced by glial cells, insulated axons with periodic breaks where nodes of Ranvier (nodes) form to allow for saltatory conduction. In the peripheral nervous system (PNS), Schwann cells are the glia that can either individually myelinate the axon from one neuron or ensheath axons of many neurons. In the central nervous system (CNS), oligodendrocytes are the glia that myelinate axons from different neurons. Review of more recent studies revealed that this myelination created polarized domains adjacent to the nodes. However, the molecular mechanisms responsible for the organization of axonal domains are only now beginning to be elucidated. The molecular domains in myelinated axons include the axon initial segment (AIS), where various ion channels are clustered and action potentials are initiated; the node, where sodium channels are clustered and action potentials are propagated; the paranode, where myelin loops contact with the axolemma; the juxtaparanode (JXP), where delayed-rectifier potassium channels are clustered; and the internode, where myelin is compactly wrapped. Each domain contains a unique subset of proteins critical for the domain's function. However, the roles of these proteins in axonal domain organization are not fully understood. In this review, we highlight recent advances on the molecular nature and functions of some of the components of each axonal domain and their roles in axonal domain organization and maintenance for proper neuronal communication.
Collapse
Affiliation(s)
- Elizabeth D Buttermore
- Curriculum in Neurobiology, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA
| | | | | |
Collapse
|
31
|
Donegan RK, Hill SE, Turnage KC, Orwig SD, Lieberman RL. The glaucoma-associated olfactomedin domain of myocilin is a novel calcium binding protein. J Biol Chem 2012; 287:43370-7. [PMID: 23129764 DOI: 10.1074/jbc.m112.408906] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Myocilin is a protein found in the trabecular meshwork extracellular matrix tissue of the eye that plays a role in regulating intraocular pressure. Both wild-type and certain myocilin variants containing mutations in the olfactomedin (OLF) domain are linked to the optic neuropathy glaucoma. Because calcium ions are important biological cofactors that play numerous roles in extracellular matrix proteins, we examined the calcium binding properties of the myocilin OLF domain (myoc-OLF). Our study reveals an unprecedented high affinity calcium binding site within myoc-OLF. The calcium ion remains bound to wild-type OLF at neutral and acidic pH. A glaucoma-causing OLF variant, myoc-OLF(D380A), is calcium-depleted. Key differences in secondary and tertiary structure between myoc-OLF(D380A) and wild-type myoc-OLF, as well as limited access to chelators, indicate that the calcium binding site is largely buried in the interior of the protein. Analysis of six conserved aspartate or glutamate residues and an additional 18 disease-causing variants revealed two other candidate residues that may be involved in calcium coordination. Our finding expands our knowledge of calcium binding in extracellular matrix proteins; provides new clues into domain structure, function, and pathogenesis for myocilin; and offers insights into highly conserved, biomedically relevant OLF domains.
Collapse
Affiliation(s)
- Rebecca K Donegan
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, USA
| | | | | | | | | |
Collapse
|
32
|
Devaux JJ. Antibodies to gliomedin cause peripheral demyelinating neuropathy and the dismantling of the nodes of Ranvier. THE AMERICAN JOURNAL OF PATHOLOGY 2012; 181:1402-13. [PMID: 22885108 DOI: 10.1016/j.ajpath.2012.06.034] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2011] [Revised: 06/15/2012] [Accepted: 06/20/2012] [Indexed: 11/18/2022]
Abstract
Guillain-Barré syndrome (GBS) and chronic inflammatory demyelinating polyneuropathy (CIDP) are conditions that affect peripheral nerves. The mechanisms that underlie demyelination in these neuropathies are unknown. Recently, we demonstrated that the node of Ranvier is the primary site of the immune attack in patients with GBS and CIDP. In particular, GBS patients have antibodies against gliomedin and neurofascin, two adhesion molecules that play a crucial role in the formation of nodes of Ranvier. We demonstrate that immunity toward gliomedin, but not neurofascin, induced a progressive neuropathy in Lewis rats characterized by conduction defects and demyelination in spinal nerves. The clinical symptoms closely followed the titers of anti-gliomedin IgG and were associated with an important deposition of IgG at nodes. Furthermore, passive transfer of antigliomedin IgG induced a severe demyelinating condition and conduction loss. In both active and passive models, the immune attack at nodes occasioned the loss of the nodal clusters for gliomedin, neurofascin-186, and voltage-gated sodium channels. These results indicate that primary immune reaction against gliomedin, a peripheral nervous system adhesion molecule, can be responsible for the initiation or progression of the demyelinating form of GBS. Furthermore, these autoantibodies affect saltatory propagation by dismantling nodal organization and sodium channel clusters. Antibodies reactive against nodal adhesion molecules thus likely participate in the pathologic process of GBS and CIDP.
Collapse
MESH Headings
- Animals
- Antibodies/immunology
- Cell Adhesion Molecules, Neuronal/immunology
- Demyelinating Diseases/immunology
- Demyelinating Diseases/pathology
- Humans
- Immunity/immunology
- Immunization
- Immunization, Passive
- Immunoglobulin G/immunology
- Male
- Mice
- Mice, Inbred C57BL
- Neuritis, Autoimmune, Experimental/immunology
- Neuritis, Autoimmune, Experimental/pathology
- Polyradiculoneuropathy, Chronic Inflammatory Demyelinating/immunology
- Polyradiculoneuropathy, Chronic Inflammatory Demyelinating/pathology
- Ranvier's Nodes/immunology
- Ranvier's Nodes/pathology
- Rats
- Rats, Inbred Lew
- Spinal Nerve Roots/pathology
Collapse
Affiliation(s)
- Jérôme J Devaux
- National Center for Scientific Research (CNRS), Aix-Marseille University, Marseille, France.
| |
Collapse
|