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Motta RV, Culver EL. IgG4 autoantibodies and autoantigens in the context of IgG4-autoimmune disease and IgG4-related disease. Front Immunol 2024; 15:1272084. [PMID: 38433835 PMCID: PMC10904653 DOI: 10.3389/fimmu.2024.1272084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Accepted: 01/25/2024] [Indexed: 03/05/2024] Open
Abstract
Immunoglobulins are an essential part of the humoral immune response. IgG4 antibodies are the least prevalent subclass and have unique structural and functional properties. In this review, we discuss IgG4 class switch and B cell production. We review the importance of IgG4 antibodies in the context of allergic responses, helminth infections and malignancy. We discuss their anti-inflammatory and tolerogenic effects in allergen-specific immunotherapy, and ability to evade the immune system in parasitic infection and tumour cells. We then focus on the role of IgG4 autoantibodies and autoantigens in IgG4-autoimmune diseases and IgG4-related disease, highlighting important parallels and differences between them. In IgG4-autoimmune diseases, pathogenesis is based on a direct role of IgG4 antibodies binding to self-antigens and disturbing homeostasis. In IgG4-related disease, where affected organs are infiltrated with IgG4-expressing plasma cells, IgG4 antibodies may also directly target a number of self-antigens or be overexpressed as an epiphenomenon of the disease. These antigen-driven processes require critical T and B cell interaction. Lastly, we explore the current gaps in our knowledge and how these may be addressed.
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Affiliation(s)
- Rodrigo V. Motta
- Translational Gastroenterology and Liver Unit, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Emma L. Culver
- Translational Gastroenterology and Liver Unit, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Department of Gastroenterology and Hepatology, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
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2
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Miguel-Hidalgo JJ, Hearn E, Moulana M, Saleem K, Clark A, Holmes M, Wadhwa K, Kelly I, Stockmeier CA, Rajkowska G. Reduced length of nodes of Ranvier and altered proteoglycan immunoreactivity in prefrontal white matter in major depressive disorder and chronically stressed rats. Sci Rep 2023; 13:16419. [PMID: 37775676 PMCID: PMC10541441 DOI: 10.1038/s41598-023-43627-4] [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: 05/11/2023] [Accepted: 09/26/2023] [Indexed: 10/01/2023] Open
Abstract
Major depressive disorder (MDD) and chronic unpredictable stress (CUS) in animals feature comparable cellular and molecular disturbances that involve neurons and glial cells in gray and white matter (WM) in prefrontal brain areas. These same areas demonstrate disturbed connectivity with other brain regions in MDD and stress-related disorders. Functional connectivity ultimately depends on signal propagation along WM myelinated axons, and thus on the integrity of nodes of Ranvier (NRs) and their environment. Various glia-derived proteoglycans interact with NR axonal proteins to sustain NR function. It is unclear whether NR length and the content of associated proteoglycans is altered in prefrontal cortex (PFC) WM of human subjects with MDD and in experimentally stressed animals. The length of WM NRs in histological sections from the PFC of 10 controls and 10 MDD subjects, and from the PFC of control and CUS rats was measured. In addition, in WM of the same brain region, five proteoglycans, tenascin-R and NR protein neurofascin were immunostained or their levels measured with western blots. Analysis of covariance and t-tests were used for group comparisons. There was dramatic reduction of NR length in PFC WM in both MDD and CUS rats. Proteoglycan BRAL1 immunostaining was reduced at NRs and in overall WM of MDD subjects, as was versican in overall WM. Phosphacan immunostaining and levels were increased in both in MDD and CUS. Neurofascin immunostaining at NRs and in overall WM was significantly increased in MDD. Reduced length of NRs and increased phosphacan and neurocan in MDD and stressed animals suggest that morphological and proteoglycan changes at NRs in depression may be related to stress exposure and contribute to connectivity alterations. However, differences between MDD and CUS for some NR related markers may point to other mechanisms affecting the structure and function of NRs in MDD.
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Affiliation(s)
- José Javier Miguel-Hidalgo
- Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, 2500 N. State Street, Jackson, MS, 39216, USA.
| | - Erik Hearn
- Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, 2500 N. State Street, Jackson, MS, 39216, USA
| | - Mohadetheh Moulana
- Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, 2500 N. State Street, Jackson, MS, 39216, USA
| | - Khunsa Saleem
- Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, 2500 N. State Street, Jackson, MS, 39216, USA
| | - Austin Clark
- Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, 2500 N. State Street, Jackson, MS, 39216, USA
| | - Maggie Holmes
- Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, 2500 N. State Street, Jackson, MS, 39216, USA
| | - Kashish Wadhwa
- Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, 2500 N. State Street, Jackson, MS, 39216, USA
| | - Isabella Kelly
- Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, 2500 N. State Street, Jackson, MS, 39216, USA
| | - Craig Allen Stockmeier
- Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, 2500 N. State Street, Jackson, MS, 39216, USA
| | - Grazyna Rajkowska
- Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, 2500 N. State Street, Jackson, MS, 39216, USA
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Dolma S, Joshi A. The Node of Ranvier as an Interface for Axo-Glial Interactions: Perturbation of Axo-Glial Interactions in Various Neurological Disorders. J Neuroimmune Pharmacol 2023; 18:215-234. [PMID: 37285016 DOI: 10.1007/s11481-023-10072-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Accepted: 05/19/2023] [Indexed: 06/08/2023]
Abstract
The action potential conduction along the axon is highly dependent on the healthy interactions between the axon and myelin-producing glial cells. Myelin, which facilitates action potential, is the protective insulation around the axon formed by Schwann cells and oligodendrocytes in the peripheral (PNS) and central nervous system (CNS), respectively. Myelin is a continuous structure with intermittent gaps called nodes of Ranvier, which are the sites enriched with ion channels, transmembrane, scaffolding, and cytoskeletal proteins. Decades-long extensive research has identified a comprehensive proteome with strictly regularized localization at the node of Ranvier. Concurrently, axon-glia interactions at the node of Ranvier have gathered significant attention as the pathophysiological targets for various neurodegenerative disorders. Numerous studies have shown the alterations in the axon-glia interactions culminating in neurological diseases. In this review, we have provided an update on the molecular composition of the node of Ranvier. Further, we have discussed in detail the consequences of disruption of axon-glia interactions during the pathogenesis of various CNS and PNS disorders.
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Affiliation(s)
- Sonam Dolma
- Department of Pharmacy, Birla Institute of Technology and Sciences- Pilani, Hyderabad campus, Telangana state, India
| | - Abhijeet Joshi
- Department of Pharmacy, Birla Institute of Technology and Sciences- Pilani, Hyderabad campus, Telangana state, India.
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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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Astrocytes as Context for the Involvement of Myelin and Nodes of Ranvier in the Pathophysiology of Depression and Stress-Related Disorders. JOURNAL OF PSYCHIATRY AND BRAIN SCIENCE 2023; 8:e230001. [PMID: 36866235 PMCID: PMC9976698 DOI: 10.20900/jpbs.20230001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Abstract
Astrocytes, despite some shared features as glial cells supporting neuronal function in gray and white matter, participate and adapt their morphology and neurochemistry in a plethora of distinct regulatory tasks in specific neural environments. In the white matter, a large proportion of the processes branching from the astrocytes' cell bodies establish contacts with oligodendrocytes and the myelin they form, while the tips of many astrocyte branches closely associate with nodes of Ranvier. Stability of myelin has been shown to greatly depend on astrocyte-to-oligodendrocyte communication, while the integrity of action potentials that regenerate at nodes of Ranvier has been shown to depend on extracellular matrix components heavily contributed by astrocytes. Several lines of evidence are starting to show that in human subjects with affective disorders and in animal models of chronic stress there are significant changes in myelin components, white matter astrocytes and nodes of Ranvier that have direct relevance to connectivity alterations in those disorders. Some of these changes involve the expression of connexins supporting astrocyte-to-oligodendrocyte gap junctions, extracellular matrix components produced by astrocytes around nodes of Ranvier, specific types of astrocyte glutamate transporters, and neurotrophic factors secreted by astrocytes that are involved in the development and plasticity of myelin. Future studies should further examine the mechanisms responsible for those changes in white matter astrocytes, their putative contribution to pathological connectivity in affective disorders, and the possibility of leveraging that knowledge to design new therapies for psychiatric disorders.
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Tufvesson H, Hamrefors V, Ohlsson B. Mechanisms behind diffuse idiopathic peripheral neuropathy in humans - a systematic review. Scand J Gastroenterol 2022; 58:572-582. [PMID: 36546668 DOI: 10.1080/00365521.2022.2160272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Introduction: Diffuse peripheral neuropathy is a well-known complication of several conditions, whereas many patients have peripheral neuropathy of unknown etiology and pathophyisology. Increased knowledge of mechanisms may provide insight into enteric neuropathy with gastrointestinal dysmotility. The aim of the present systematic review was to identify mechanisms behind diffuse idiopathic peripheral neuropathies in humans.Methods: Searches were performed in PubMed, Embase, and Web of Science. Human original and review articles, written in English, describing mechanisms behind diffuse peripheral neuropathy verified by objective examinations were intended to be studied. Articles that described animal models, well-described hereditary diseases, drug-induced neuropathy, pain syndromes, malnutrition, and local neuropathy were excluded.Results: In total, 4712 articles were identified. After scrutinizing titles and abstracts, 633 remained and were studied in full text. After the removal of articles not fulfilling inclusion or exclusion criteria, 52 were finally included in this review. The most frequently described neuropathy was diabetic neuropathy, with a wide range of mechanisms involving mitochondrial dysfunction such as oxidative stress and inflammation. Microvascular changes in diabetes and vasculitis lead to ischemia and secondary oxidative stress with inflammation. Structural changes in neurons and glial cells are observed, with abnormalities in different neurotrophic factors. Neuropathy induced by autoantibodies or immunological mechanisms is described in infectious and systemic inflammatory diseases. Several ion channels may be involved in painful neuropathy. No study identified why some patients mainly develop large fiber neuropathy and others small fiber neuropathy.Conclusion: Metabolic and immunological factors and channelopathy may be considered in diffuse idiopathic peripheral neuropathy.
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Affiliation(s)
- Hanna Tufvesson
- Department of Clinical Sciences, Lund University, Lund, Sweden.,Department of Gastroenterology and Hepatology, Skåne University Hopsital, Malmö, Sweden
| | - Viktor Hamrefors
- Department of Clinical Sciences, Lund University, Lund, Sweden.,Department of Cardiology, Skåne University Hospital, Malmö, Sweden
| | - Bodil Ohlsson
- Department of Clinical Sciences, Lund University, Lund, Sweden.,Department of Internal Medicine, Skåne University Hopsital, Malmö, Sweden
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7
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Bizzoca A, Jirillo E, Flace P, Gennarini G. Overall Role of Contactins Expression in Neurodevelopmental Events and Contribution to Neurological Disorders. CNS & NEUROLOGICAL DISORDERS DRUG TARGETS 2022; 22:CNSNDDT-EPUB-128217. [PMID: 36515028 DOI: 10.2174/1871527322666221212160048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 10/21/2022] [Accepted: 10/28/2022] [Indexed: 12/15/2022]
Abstract
BACKGROUND Neurodegenerative disorders may depend upon a misregulation of the pathways which sustain neurodevelopmental control. In this context, this review article focuses on Friedreich ataxia (FA), a neurodegenerative disorder resulting from mutations within the gene encoding the Frataxin protein, which is involved in the control of mitochondrial function and oxidative metabolism. OBJECTIVE The specific aim of the present study concerns the FA molecular and cellular substrates, for which available transgenic mice models are proposed, including mutants undergoing misexpression of adhesive/morphoregulatory proteins, in particular belonging to the Contactin subset of the immunoglobulin supergene family. METHODS In both mutant and control mice, neurogenesis was explored by morphological/morphometric analysis through the expression of cell type-specific markers, including -tubulin, the Contactin-1 axonal adhesive glycoprotein, as well as the Glial Fibrillary Acidic Protein (GFAP). RESULTS Specific consequences were found to arise from the chosen misexpression approach, consisting of a neuronal developmental delay associated with glial upregulation. Protective effects against the arising phenotype resulted from antioxidants (essentially epigallocatechin gallate (EGCG)) administration, which was demonstrated through the profiles of neuronal (-tubulin and Contactin 1) as well as glial (GFAP) markers, in turn indicating the concomitant activation of neurodegeneration and neuro repair processes. The latter also implied activation of the Notch-1 signaling. CONCLUSION Overall, this study supports the significance of changes in morphoregulatory proteins expression in the FA pathogenesis and of antioxidant administration in counteracting it, which, in turn, allows to devise potential therapeutic approaches.
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Affiliation(s)
- Antonella Bizzoca
- Department of Basic Medical Sciences, Neurosciences, and Sensory Organs. Medical School. University of Bari. Piazza Giulio Cesare, 11. I-70124 Bari. Italy
| | - Emilio Jirillo
- Department of Basic Medical Sciences, Neurosciences, and Sensory Organs. Medical School. University of Bari. Piazza Giulio Cesare, 11. I-70124 Bari. Italy
| | - Paolo Flace
- Department of Basic Medical Sciences, Neurosciences, and Sensory Organs. Medical School. University of Bari. Piazza Giulio Cesare, 11. I-70124 Bari. Italy
| | - Gianfranco Gennarini
- Department of Basic Medical Sciences, Neurosciences, and Sensory Organs. Medical School. University of Bari. Piazza Giulio Cesare, 11. I-70124 Bari. Italy
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8
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Zhao N, Chang S, Zhang Q, Zhang L, Jiang S, Zhai H, Yang L. Clinical features of
Guillain–Barré
syndrome with anti‐neurofascin 155 antibody. Acta Neurol Scand 2022; 146:553-561. [DOI: 10.1111/ane.13678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 07/14/2022] [Accepted: 07/24/2022] [Indexed: 12/01/2022]
Affiliation(s)
- Ning Zhao
- Department of Neurology, Tianjin Neurological Institute Tianjin Medical University General Hospital Tianjin China
| | - Sheng‐Hui Chang
- Department of Neurology, Tianjin Neurological Institute Tianjin Medical University General Hospital Tianjin China
| | - Qiu‐Xia Zhang
- Department of Neurology, Tianjin Neurological Institute Tianjin Medical University General Hospital Tianjin China
| | - Lin‐Jie Zhang
- Department of Neurology, Tianjin Neurological Institute Tianjin Medical University General Hospital Tianjin China
| | - Shu‐Min Jiang
- Department of Neurology, Tianjin Neurological Institute Tianjin Medical University General Hospital Tianjin China
| | - Hui Zhai
- Department of Neurology, Tianjin Neurological Institute Tianjin Medical University General Hospital Tianjin China
| | - Li Yang
- Department of Neurology, Tianjin Neurological Institute Tianjin Medical University General Hospital Tianjin China
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9
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Ishibashi T, Baba H. Paranodal Axoglial Junctions, an Essential Component in Axonal Homeostasis. Front Cell Dev Biol 2022; 10:951809. [PMID: 35874818 PMCID: PMC9299063 DOI: 10.3389/fcell.2022.951809] [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: 05/24/2022] [Accepted: 06/20/2022] [Indexed: 11/28/2022] Open
Abstract
In vertebrates, a high density of voltage-gated Na+ channel at nodes of Ranvier and of voltage-gated K+ channel at juxtaparanodes is necessary for rapid propagation of action potential, that is, for saltatory conduction in myelinated axons. Myelin loops attach to the axonal membrane and form paranodal axoglial junctions (PNJs) at paranodes adjacent to nodes of Ranvier. There is growing evidence that the PNJs contribute to axonal homeostasis in addition to their roles as lateral fences that restrict the location of nodal axolemmal proteins for effective saltatory conduction. Perturbations of PNJs, as in specific PNJ protein knockouts as well as in myelin lipid deficient mice, result in internodal axonal alterations, even if their internodal myelin is preserved. Here we review studies showing that PNJs play crucial roles in the myelinated axonal homeostasis. The present evidence points to two functions in particular: 1) PNJs facilitate axonal transport of membranous organelles as well as cytoskeletal proteins; and 2) they regulate the axonal distribution of type 1 inositol 1,4,5-trisphosphate receptor (IP3R1) in cerebellar Purkinje axons. Myelinated axonal homeostasis depends among others on the state of PNJs, and consequently, a better understanding of this dependency may contribute to the clarification of CNS disease mechanisms and the development of novel therapies.
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Affiliation(s)
- Tomoko Ishibashi
- Department of Functional Neurobiology, Tokyo University of Pharmacy and Life Sciences, Hachioji, Japan
| | - Hiroko Baba
- Department of Occupational Therapy, Faculty of Rehabilitation, Niigata University of Health and Welfare, Niigata, Japan
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Jeon MY, Seok JM, Fujihara K, Kim BJ. Autoantibodies in central nervous system and neuromuscular autoimmune disorders: A narrative review. PRECISION AND FUTURE MEDICINE 2022. [DOI: 10.23838/pfm.2021.00198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The discovery of novel autoantibodies in neurological disorders contributes to a better understanding of its pathogenesis, improves the accuracy of diagnosis, and leads to new treatment strategies. Advances in techniques for the screening and detection of autoantibodies have enabled the discovery of new antibodies in the central nervous system (CNS) and neuromuscular diseases. Cell-based assays using live or fixed cells overexpressing target antigens are widely used for autoantibody-based diagnosis in clinical practice. Common pathogenic autoantibodies are unknown in most patients with multiple sclerosis (MS) and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). Novel pathogenic autoantibodies to aquaporin-4 and myelin oligodendrocyte glycoprotein (MOG) have been identified in neuromyelitis optica spectrum disorder and MOG antibody-associated disease, respectively. These diseases have clinical similarities to MS, but with the discovery of pathogenic autoantibodies, they are now recognized as distinct disease entities. Antibodies to paranodal membrane proteins such as neurofascin-155, contactin‑1, contactin‑associated protein‑1 in CIDP and muscle-specific kinase and low-density lipoprotein receptor–related protein 4 in myasthenia gravis were added to the profiles of autoantibodies in neurological disorders. Despite the relatively low frequency of seropositivity, autoantibody detection is currently essential for the clinical diagnosis of CNS and neuromuscular autoimmune disorders, and differential approaches to seropositive patients will contribute to more personalized medicine. We reviewed recent discoveries of autoantibodies and their clinical implications in CNS and neuromuscular disorders.
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11
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Pathophysiology of the Different Clinical Phenotypes of Chronic Inflammatory Demyelinating Polyradiculoneuropathy (CIDP). Int J Mol Sci 2021; 23:ijms23010179. [PMID: 35008604 PMCID: PMC8745770 DOI: 10.3390/ijms23010179] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Revised: 12/17/2021] [Accepted: 12/21/2021] [Indexed: 12/22/2022] Open
Abstract
Chronic inflammatory demyelinating polyneuropathy (CIDP) is the most common form of autoimmune polyneuropathy. It is a chronic disease and may be monophasic, progressive or recurrent with exacerbations and incomplete remissions, causing accumulating disability. In recent years, there has been rapid progress in understanding the background of CIDP, which allowed us to distinguish specific phenotypes of this disease. This in turn allowed us to better understand the mechanism of response or non-response to various forms of therapy. On the basis of a review of the relevant literature, the authors present the current state of knowledge concerning the pathophysiology of the different clinical phenotypes of CIDP as well as ongoing research in this field, with reference to key points of immune-mediated processes involved in the background of CIDP.
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12
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Frob F, Wegner M. Coordination of Schwann cell myelination and node formation at the transcriptional level. Neural Regen Res 2021; 17:1269-1270. [PMID: 34782568 PMCID: PMC8643042 DOI: 10.4103/1673-5374.327343] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Affiliation(s)
- Franziska Frob
- Institut für Biochemie, Emil-Fischer-Zentrum, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Michael Wegner
- Institut für Biochemie, Emil-Fischer-Zentrum, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
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13
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Wieske L, Martín-Aguilar L, Fehmi J, Lleixà C, Koel-Simmelink MJA, Chatterjee M, van Lierop Z, Killestein J, Verhamme C, Querol L, Rinaldi S, Teunissen CE, Eftimov F. Serum Contactin-1 in CIDP: A Cross-Sectional Study. NEUROLOGY-NEUROIMMUNOLOGY & NEUROINFLAMMATION 2021; 8:8/5/e1040. [PMID: 34285092 PMCID: PMC8293285 DOI: 10.1212/nxi.0000000000001040] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 05/20/2021] [Indexed: 11/29/2022]
Abstract
Objective To investigate whether serum levels of contactin-1, a paranodal protein, correlate with paranodal injury as seen in patients with CIDP with antibodies targeting the paranodal region. Methods Serum contactin-1 levels were measured in 187 patients with CIDP and 222 healthy controls. Paranodal antibodies were investigated in all patients. Results Serum contactin-1 levels were lower in patients (N = 41) with paranodal antibodies compared with patients (N = 146) without paranodal antibodies (p < 0.01) and showed good discrimination between these groups (area under the curve 0.84; 95% CI: 0.76–0.93). Conclusions These findings suggest that serum contactin-1 levels have the potential to serve as a possible diagnostic biomarker of paranodal injury in CIDP. Classification of Evidence This study provides class II evidence that serum contactin-1 levels can discriminate between patients with CIDP with or without paranodal antibodies with a sensitivity of 71% (95% CI: 56%–85%) and a specificity of 97% (95% CI: 83%–100%).
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Affiliation(s)
- Luuk Wieske
- From the Department of Neurology and Neurophysiology (L.W., C.V., F.E.), Amsterdam Neuroscience, Amsterdam UMC, Location AMC, Amsterdam, the Netherlands; Neuromuscular Diseases Unit (L.M.-A., C.L., L.Q.), Department of Neurology, Hospital de La Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Spain; Department of Clinical Neurosciences (J.F., S.R.), West Wing, John Radcliffe Hospital, Oxford, United Kingdom; Neurochemistry Lab (M.J.A.K.-S., C.E.T.), Department of Clinical Chemistry, Amsterdam Neuroscience, Amsterdam UMC, Vrije Universiteit, Amsterdam, the Netherlands; and Department of Neurology (M.C., Z.L., J.K.), Amsterdam Neuroscience, Amsterdam UMC, Location VU Medical Center, Amsterdam, the Netherlands.
| | - Lorena Martín-Aguilar
- From the Department of Neurology and Neurophysiology (L.W., C.V., F.E.), Amsterdam Neuroscience, Amsterdam UMC, Location AMC, Amsterdam, the Netherlands; Neuromuscular Diseases Unit (L.M.-A., C.L., L.Q.), Department of Neurology, Hospital de La Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Spain; Department of Clinical Neurosciences (J.F., S.R.), West Wing, John Radcliffe Hospital, Oxford, United Kingdom; Neurochemistry Lab (M.J.A.K.-S., C.E.T.), Department of Clinical Chemistry, Amsterdam Neuroscience, Amsterdam UMC, Vrije Universiteit, Amsterdam, the Netherlands; and Department of Neurology (M.C., Z.L., J.K.), Amsterdam Neuroscience, Amsterdam UMC, Location VU Medical Center, Amsterdam, the Netherlands
| | - Janev Fehmi
- From the Department of Neurology and Neurophysiology (L.W., C.V., F.E.), Amsterdam Neuroscience, Amsterdam UMC, Location AMC, Amsterdam, the Netherlands; Neuromuscular Diseases Unit (L.M.-A., C.L., L.Q.), Department of Neurology, Hospital de La Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Spain; Department of Clinical Neurosciences (J.F., S.R.), West Wing, John Radcliffe Hospital, Oxford, United Kingdom; Neurochemistry Lab (M.J.A.K.-S., C.E.T.), Department of Clinical Chemistry, Amsterdam Neuroscience, Amsterdam UMC, Vrije Universiteit, Amsterdam, the Netherlands; and Department of Neurology (M.C., Z.L., J.K.), Amsterdam Neuroscience, Amsterdam UMC, Location VU Medical Center, Amsterdam, the Netherlands
| | - Cinta Lleixà
- From the Department of Neurology and Neurophysiology (L.W., C.V., F.E.), Amsterdam Neuroscience, Amsterdam UMC, Location AMC, Amsterdam, the Netherlands; Neuromuscular Diseases Unit (L.M.-A., C.L., L.Q.), Department of Neurology, Hospital de La Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Spain; Department of Clinical Neurosciences (J.F., S.R.), West Wing, John Radcliffe Hospital, Oxford, United Kingdom; Neurochemistry Lab (M.J.A.K.-S., C.E.T.), Department of Clinical Chemistry, Amsterdam Neuroscience, Amsterdam UMC, Vrije Universiteit, Amsterdam, the Netherlands; and Department of Neurology (M.C., Z.L., J.K.), Amsterdam Neuroscience, Amsterdam UMC, Location VU Medical Center, Amsterdam, the Netherlands
| | - Marleen J A Koel-Simmelink
- From the Department of Neurology and Neurophysiology (L.W., C.V., F.E.), Amsterdam Neuroscience, Amsterdam UMC, Location AMC, Amsterdam, the Netherlands; Neuromuscular Diseases Unit (L.M.-A., C.L., L.Q.), Department of Neurology, Hospital de La Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Spain; Department of Clinical Neurosciences (J.F., S.R.), West Wing, John Radcliffe Hospital, Oxford, United Kingdom; Neurochemistry Lab (M.J.A.K.-S., C.E.T.), Department of Clinical Chemistry, Amsterdam Neuroscience, Amsterdam UMC, Vrije Universiteit, Amsterdam, the Netherlands; and Department of Neurology (M.C., Z.L., J.K.), Amsterdam Neuroscience, Amsterdam UMC, Location VU Medical Center, Amsterdam, the Netherlands
| | - Madhurima Chatterjee
- From the Department of Neurology and Neurophysiology (L.W., C.V., F.E.), Amsterdam Neuroscience, Amsterdam UMC, Location AMC, Amsterdam, the Netherlands; Neuromuscular Diseases Unit (L.M.-A., C.L., L.Q.), Department of Neurology, Hospital de La Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Spain; Department of Clinical Neurosciences (J.F., S.R.), West Wing, John Radcliffe Hospital, Oxford, United Kingdom; Neurochemistry Lab (M.J.A.K.-S., C.E.T.), Department of Clinical Chemistry, Amsterdam Neuroscience, Amsterdam UMC, Vrije Universiteit, Amsterdam, the Netherlands; and Department of Neurology (M.C., Z.L., J.K.), Amsterdam Neuroscience, Amsterdam UMC, Location VU Medical Center, Amsterdam, the Netherlands
| | - Zoë van Lierop
- From the Department of Neurology and Neurophysiology (L.W., C.V., F.E.), Amsterdam Neuroscience, Amsterdam UMC, Location AMC, Amsterdam, the Netherlands; Neuromuscular Diseases Unit (L.M.-A., C.L., L.Q.), Department of Neurology, Hospital de La Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Spain; Department of Clinical Neurosciences (J.F., S.R.), West Wing, John Radcliffe Hospital, Oxford, United Kingdom; Neurochemistry Lab (M.J.A.K.-S., C.E.T.), Department of Clinical Chemistry, Amsterdam Neuroscience, Amsterdam UMC, Vrije Universiteit, Amsterdam, the Netherlands; and Department of Neurology (M.C., Z.L., J.K.), Amsterdam Neuroscience, Amsterdam UMC, Location VU Medical Center, Amsterdam, the Netherlands
| | - Joep Killestein
- From the Department of Neurology and Neurophysiology (L.W., C.V., F.E.), Amsterdam Neuroscience, Amsterdam UMC, Location AMC, Amsterdam, the Netherlands; Neuromuscular Diseases Unit (L.M.-A., C.L., L.Q.), Department of Neurology, Hospital de La Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Spain; Department of Clinical Neurosciences (J.F., S.R.), West Wing, John Radcliffe Hospital, Oxford, United Kingdom; Neurochemistry Lab (M.J.A.K.-S., C.E.T.), Department of Clinical Chemistry, Amsterdam Neuroscience, Amsterdam UMC, Vrije Universiteit, Amsterdam, the Netherlands; and Department of Neurology (M.C., Z.L., J.K.), Amsterdam Neuroscience, Amsterdam UMC, Location VU Medical Center, Amsterdam, the Netherlands
| | - Camiel Verhamme
- From the Department of Neurology and Neurophysiology (L.W., C.V., F.E.), Amsterdam Neuroscience, Amsterdam UMC, Location AMC, Amsterdam, the Netherlands; Neuromuscular Diseases Unit (L.M.-A., C.L., L.Q.), Department of Neurology, Hospital de La Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Spain; Department of Clinical Neurosciences (J.F., S.R.), West Wing, John Radcliffe Hospital, Oxford, United Kingdom; Neurochemistry Lab (M.J.A.K.-S., C.E.T.), Department of Clinical Chemistry, Amsterdam Neuroscience, Amsterdam UMC, Vrije Universiteit, Amsterdam, the Netherlands; and Department of Neurology (M.C., Z.L., J.K.), Amsterdam Neuroscience, Amsterdam UMC, Location VU Medical Center, Amsterdam, the Netherlands
| | - Luis Querol
- From the Department of Neurology and Neurophysiology (L.W., C.V., F.E.), Amsterdam Neuroscience, Amsterdam UMC, Location AMC, Amsterdam, the Netherlands; Neuromuscular Diseases Unit (L.M.-A., C.L., L.Q.), Department of Neurology, Hospital de La Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Spain; Department of Clinical Neurosciences (J.F., S.R.), West Wing, John Radcliffe Hospital, Oxford, United Kingdom; Neurochemistry Lab (M.J.A.K.-S., C.E.T.), Department of Clinical Chemistry, Amsterdam Neuroscience, Amsterdam UMC, Vrije Universiteit, Amsterdam, the Netherlands; and Department of Neurology (M.C., Z.L., J.K.), Amsterdam Neuroscience, Amsterdam UMC, Location VU Medical Center, Amsterdam, the Netherlands
| | - Simon Rinaldi
- From the Department of Neurology and Neurophysiology (L.W., C.V., F.E.), Amsterdam Neuroscience, Amsterdam UMC, Location AMC, Amsterdam, the Netherlands; Neuromuscular Diseases Unit (L.M.-A., C.L., L.Q.), Department of Neurology, Hospital de La Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Spain; Department of Clinical Neurosciences (J.F., S.R.), West Wing, John Radcliffe Hospital, Oxford, United Kingdom; Neurochemistry Lab (M.J.A.K.-S., C.E.T.), Department of Clinical Chemistry, Amsterdam Neuroscience, Amsterdam UMC, Vrije Universiteit, Amsterdam, the Netherlands; and Department of Neurology (M.C., Z.L., J.K.), Amsterdam Neuroscience, Amsterdam UMC, Location VU Medical Center, Amsterdam, the Netherlands
| | - Charlotte E Teunissen
- From the Department of Neurology and Neurophysiology (L.W., C.V., F.E.), Amsterdam Neuroscience, Amsterdam UMC, Location AMC, Amsterdam, the Netherlands; Neuromuscular Diseases Unit (L.M.-A., C.L., L.Q.), Department of Neurology, Hospital de La Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Spain; Department of Clinical Neurosciences (J.F., S.R.), West Wing, John Radcliffe Hospital, Oxford, United Kingdom; Neurochemistry Lab (M.J.A.K.-S., C.E.T.), Department of Clinical Chemistry, Amsterdam Neuroscience, Amsterdam UMC, Vrije Universiteit, Amsterdam, the Netherlands; and Department of Neurology (M.C., Z.L., J.K.), Amsterdam Neuroscience, Amsterdam UMC, Location VU Medical Center, Amsterdam, the Netherlands
| | - Filip Eftimov
- From the Department of Neurology and Neurophysiology (L.W., C.V., F.E.), Amsterdam Neuroscience, Amsterdam UMC, Location AMC, Amsterdam, the Netherlands; Neuromuscular Diseases Unit (L.M.-A., C.L., L.Q.), Department of Neurology, Hospital de La Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Spain; Department of Clinical Neurosciences (J.F., S.R.), West Wing, John Radcliffe Hospital, Oxford, United Kingdom; Neurochemistry Lab (M.J.A.K.-S., C.E.T.), Department of Clinical Chemistry, Amsterdam Neuroscience, Amsterdam UMC, Vrije Universiteit, Amsterdam, the Netherlands; and Department of Neurology (M.C., Z.L., J.K.), Amsterdam Neuroscience, Amsterdam UMC, Location VU Medical Center, Amsterdam, the Netherlands
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14
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van Lierop ZY, Wieske L, Koel-Simmelink MJ, Chatterjee M, Dekker I, Leurs CE, Willemse EA, Moraal B, Barkhof F, Eftimov F, Uitdehaag BM, Killestein J, Teunissen CE. Serum contactin-1 as a biomarker of long-term disease progression in natalizumab-treated multiple sclerosis. Mult Scler 2021; 28:102-110. [PMID: 33890520 PMCID: PMC8689420 DOI: 10.1177/13524585211010097] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
BACKGROUND Natalizumab treatment provides a model for non-inflammation-induced disease progression in multiple sclerosis (MS). OBJECTIVE To study serum contactin-1 (sCNTN1) as a novel biomarker for disease progression in natalizumab-treated relapsing-remitting MS (RRMS) patients. METHODS Eighty-nine natalizumab-treated RRMS patients with minimum follow-up of 3 years were included. sCNTN1 was analyzed at baseline (before natalizumab initiation), 3, 12, 24 months (M) and last follow-up (median 5.2 years) and compared to 222 healthy controls (HC) and 15 primary progressive MS patients (PPMS). Results were compared between patients with progressive, stable, or improved disability according to EDSS-plus criteria. RESULTS Median sCNTN1 levels (ng/mL,) in RRMS (baseline: 10.7, 3M: 9.7, 12M: 10.4, 24M: 10.8; last follow-up: 9.7) were significantly lower compared to HC (12.5; p ⩽ 0.001). It was observed that 48% of patients showed progression during follow-up, 11% improved, and 40% remained stable. sCNTN1 levels were significantly lower in progressors both at baseline and at 12M compared to non-progressors. A 1 ng/mL decrease in baseline sCNTN1 was consistent with an odds ratio of 1.23 (95% confidence interval 1.04-1.45) (p = 0.017) for progression during follow-up. CONCLUSION Lower baseline sCNTN1 concentrations were associated with long-term disability progression during natalizumab treatment, making it a possible blood-based prognostic biomarker for RRMS.
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Affiliation(s)
- Zoë Ygj van Lierop
- Department of Neurology, Amsterdam UMC, Vrije Universiteit Amsterdam, MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Luuk Wieske
- Department of Neurology and Neurophysiology, Amsterdam UMC, Academisch Medisch Centrum, Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Marleen Ja Koel-Simmelink
- Department of Clinical Chemistry, Amsterdam UMC, Vrije Universiteit Amsterdam, Neurochemistry Laboratory and Biobank, Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Madhurima Chatterjee
- Department of Clinical Chemistry, Amsterdam UMC, Vrije Universiteit Amsterdam, Neurochemistry Laboratory and Biobank, Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Iris Dekker
- Department of Neurology, Amsterdam UMC, Vrije Universiteit Amsterdam, MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam, The Netherlands/Department of Rehabilitation Medicine, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Cyra E Leurs
- Department of Neurology, Amsterdam UMC, Vrije Universiteit Amsterdam, MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Eline Aj Willemse
- Department of Clinical Chemistry, Amsterdam UMC, Vrije Universiteit Amsterdam, Neurochemistry Laboratory and Biobank, Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Bastiaan Moraal
- Department of Radiology and Nuclear Medicine, Amsterdam UMC, Vrije Universiteit Amsterdam, MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Frederik Barkhof
- Department of Radiology and Nuclear Medicine, Amsterdam UMC, Vrije Universiteit Amsterdam, MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam, The Netherlands/Institutes of Neurology and Healthcare Engineering, University College London, London, UK
| | - Filip Eftimov
- Department of Neurology and Neurophysiology, Amsterdam UMC, Academisch Medisch Centrum, Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Bernhard Mj Uitdehaag
- Department of Neurology, Amsterdam UMC, Vrije Universiteit Amsterdam, MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Joep Killestein
- Department of Neurology, Amsterdam UMC, Vrije Universiteit Amsterdam, MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Charlotte E Teunissen
- Department of Clinical Chemistry, Amsterdam UMC, Vrije Universiteit Amsterdam, Neurochemistry Laboratory and Biobank, Amsterdam Neuroscience, Amsterdam, The Netherlands
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15
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Saur AL, Fröb F, Weider M, Wegner M. Formation of the node of Ranvier by Schwann cells is under control of transcription factor Sox10. Glia 2021; 69:1464-1477. [PMID: 33566433 DOI: 10.1002/glia.23973] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 01/21/2021] [Accepted: 01/25/2021] [Indexed: 11/06/2022]
Abstract
The transcription factor Sox10 is an essential regulator of genes that code for structural components of the myelin sheath and for lipid metabolic enzymes in both types of myelinating glia in the central and peripheral nervous systems. In an attempt to characterize additional Sox10 target genes in Schwann cells, we identified in this study a strong influence of Sox10 on the expression of genes associated with adhesion in the MSC80 Schwann cell line. These included the genes for Gliomedin, Neuronal cell adhesion molecule and Neurofascin that together constitute essential Schwann cell contributions to paranode and node of Ranvier. Using bioinformatics and molecular biology techniques we provide evidence that Sox10 directly activates these genes by binding to conserved regulatory regions. For activation, Sox10 cooperates with Krox20, a transcription factor previously identified as the central regulator of Schwann cell myelination. Both the activating function of Sox10 as well as its cooperation with Krox20 were confirmed in vivo. We conclude that the employment of Sox10 and Krox20 as regulators of structural myelin sheath components and genes associated with the node of Ranvier is one way of ensuring a biologically meaningful coordinated formation of both structures during peripheral myelination.
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Affiliation(s)
- Anna-Lena Saur
- Institut für Biochemie, Emil-Fischer-Zentrum, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Franziska Fröb
- Institut für Biochemie, Emil-Fischer-Zentrum, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Matthias Weider
- Institut für Biochemie, Emil-Fischer-Zentrum, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany.,Zahnklinik 3 - Kieferorthopädie, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Michael Wegner
- Institut für Biochemie, Emil-Fischer-Zentrum, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
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16
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Kalafatakis I, Savvaki M, Velona T, Karagogeos D. Implication of Contactins in Demyelinating Pathologies. Life (Basel) 2021; 11:life11010051. [PMID: 33451101 PMCID: PMC7828632 DOI: 10.3390/life11010051] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 01/09/2021] [Accepted: 01/11/2021] [Indexed: 12/19/2022] Open
Abstract
Demyelinating pathologies comprise of a variety of conditions where either central or peripheral myelin is attacked, resulting in white matter lesions and neurodegeneration. Myelinated axons are organized into molecularly distinct domains, and this segregation is crucial for their proper function. These defined domains are differentially affected at the different stages of demyelination as well as at the lesion and perilesion sites. Among the main players in myelinated axon organization are proteins of the contactin (CNTN) group of the immunoglobulin superfamily (IgSF) of cell adhesion molecules, namely Contactin-1 and Contactin-2 (CNTN1, CNTN2). The two contactins perform their functions through intermolecular interactions, which are crucial for myelinated axon integrity and functionality. In this review, we focus on the implication of these two molecules as well as their interactors in demyelinating pathologies in humans. At first, we describe the organization and function of myelinated axons in the central (CNS) and the peripheral (PNS) nervous system, further analyzing the role of CNTN1 and CNTN2 as well as their interactors in myelination. In the last section, studies showing the correlation of the two contactins with demyelinating pathologies are reviewed, highlighting the importance of these recognition molecules in shaping the function of the nervous system in multiple ways.
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17
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Bizzoca A, Caracciolo M, Corsi P, Magrone T, Jirillo E, Gennarini G. Molecular and Cellular Substrates for the Friedreich Ataxia. Significance of Contactin Expression and of Antioxidant Administration. Molecules 2020; 25:E4085. [PMID: 32906751 PMCID: PMC7570916 DOI: 10.3390/molecules25184085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 08/28/2020] [Accepted: 09/02/2020] [Indexed: 11/16/2022] Open
Abstract
In this study, the neural phenotype is explored in rodent models of the spinocerebellar disorder known as the Friedreich Ataxia (FA), which results from mutations within the gene encoding the Frataxin mitochondrial protein. For this, the M12 line, bearing a targeted mutation, which disrupts the Frataxin gene exon 4 was used, together with the M02 line, which, in addition, is hemizygous for the human Frataxin gene mutation (Pook transgene), implying the occurrence of 82-190 GAA repeats within its first intron. The mutant mice phenotype was compared to the one of wild type littermates in regions undergoing differential profiles of neurogenesis, including the cerebellar cortex and the spinal cord by using neuronal (β-tubulin) and glial (Glial Fibrillary Acidic Protein) markers as well as the Contactin 1 axonal glycoprotein, involved in neurite growth control. Morphological/morphometric analyses revealed that while in Frataxin mutant mice the neuronal phenotype was significantly counteracted, a glial upregulation occurred at the same time. Furthermore, Contactin 1 downregulation suggested that changes in the underlying gene contributed to the disorder pathogenesis. Therefore, the FA phenotype implies an alteration of the developmental profile of neuronal and glial precursors. Finally, epigallocatechin gallate polyphenol administration counteracted the disorder, indicating protective effects of antioxidant administration.
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Affiliation(s)
| | | | | | | | | | - Gianfranco Gennarini
- Department of Basic Medical Sciences, Neurosciences and Sensory Organs, Medical School, University of Bari, Piazza Giulio Cesare, 11. I-70124 Bari, Italy; (A.B.); (M.C.); (P.C.); (T.M.); (E.J.)
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18
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Koneczny I. Update on IgG4-mediated autoimmune diseases: New insights and new family members. Autoimmun Rev 2020; 19:102646. [PMID: 32801046 DOI: 10.1016/j.autrev.2020.102646] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Accepted: 03/08/2020] [Indexed: 12/23/2022]
Abstract
Antibodies of IgG4 subclass are exceptional players of the immune system, as they are considered to be immunologically inert and functionally monovalent, and as such may be part of classical tolerance mechanisms. IgG4 antibodies are found in a range of different diseases, including IgG4-related diseases, allergy, cancer, rheumatoid arthritis, helminth infection and IgG4 autoimmune diseases, where they may be pathogenic or protective. IgG4 autoimmune diseases are an emerging new group of diseases that are characterized by pathogenic, antigen-specific autoantibodies of IgG4 subclass, such as MuSK myasthenia gravis, pemphigus vulgaris and thrombotic thrombocytopenic purpura. The list of IgG4 autoantigens is rapidly growing and to date contains 29 candidate antigens. Interestingly, IgG4 autoimmune diseases are restricted to four distinct organs: 1) the central and peripheral nervous system, 2) the kidney, 3) the skin and mucous membranes and 4) the vascular system and soluble antigens in the blood circulation. The pathogenicity of IgG4 can be validated using our classification system, and is usually excerted by functional blocking of protein-protein interaction.
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Affiliation(s)
- Inga Koneczny
- Division of Neuropathology and Neurochemistry, Department of Neurology, Medical University of Vienna, Währingergürtel 18-20, 1090 Vienna, Austria.
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19
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Lubetzki C, Sol-Foulon N, Desmazières A. Nodes of Ranvier during development and repair in the CNS. Nat Rev Neurol 2020; 16:426-439. [DOI: 10.1038/s41582-020-0375-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/04/2020] [Indexed: 01/01/2023]
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20
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Portaro S, Biasini F, Bramanti P, Naro A, Calabrò RS. Chronic inflammatory demyelinating polyradiculoneuropathy relapse after mexiletine withdrawal in a patient with concomitant myotonia congenita: A case report on a potential treatment option. Medicine (Baltimore) 2020; 99:e21117. [PMID: 32664137 PMCID: PMC7360317 DOI: 10.1097/md.0000000000021117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
INTRODUCTION we report on the first case of a woman affected by chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and recessive myotonia congenita (MC), treated with mexiletine. We aimed at describing the possible role of mexiletine in CIDP management. PATIENT CONCERNS A 44-year-old female affected by CIDP and MC, gained beneficial effects for CIDP symptoms (muscle weakness, cramps, and fatigue) and relapses, after mexiletine intake (200 mg twice a day). The patient presented with detrimental effects after mexiletine drop out, with a worsening of CIDP symptoms. INTERVENTIONS The patient reported a nearly complete remission of muscle stiffness and weakness up to 3 years since mexiletine intake. Then, she developed an allergic reaction with glottis edema, maybe related to mexiletine intake, as per emergency room doctors' evaluation, who suggested withdrawing the drug. OUTCOMES The patient significantly worsened after the medication drop out concerning both CIDP and MC symptoms. CONCLUSION This is the first report on the association of CIDP and MC in the same patient. Such diseases may share some clinical symptoms related to a persistent sodium currents increase, which maybe due either to the over-expression of sodium channels following axonal damage due to demyelination or to the chloride channel genes mutations. This is the possible reason why mexiletine maybe promising to treat CIDP symptoms.
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Accumulation of Neurofascin at Nodes of Ranvier Is Regulated by a Paranodal Switch. J Neurosci 2020; 40:5709-5723. [PMID: 32554548 DOI: 10.1523/jneurosci.0830-19.2020] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 04/29/2020] [Accepted: 06/02/2020] [Indexed: 12/18/2022] Open
Abstract
The paranodal junctions flank mature nodes of Ranvier and provide a barrier between ion channels at the nodes and juxtaparanodes. These junctions also promote node assembly and maintenance by mechanisms that are poorly understood. Here, we examine their role in the accumulation of NF186, a key adhesion molecule of PNS and CNS nodes. We previously showed that NF186 is initially targeted/accumulates via its ectodomain to forming PNS (hemi)nodes by diffusion trapping, whereas it is later targeted to mature nodes by a transport-dependent mechanism mediated by its cytoplasmic segment. To address the role of the paranodes in this switch, we compared accumulation of NF186 ectodomain and cytoplasmic domain constructs in WT versus paranode defective (i.e., Caspr-null) mice. Both pathways are affected in the paranodal mutants. In the PNS of Caspr-null mice, diffusion trapping mediated by the NF186 ectodomain aberrantly persists into adulthood, whereas the cytoplasmic domain/transport-dependent targeting is impaired. In contrast, accumulation of NF186 at CNS nodes does not undergo a switch; it is predominantly targeted to both forming and mature CNS nodes via its cytoplasmic domain and requires intact paranodes. Fluorescence recovery after photobleaching analysis indicates that the paranodes provide a membrane diffusion barrier that normally precludes diffusion of NF186 to nodes. Linkage of paranodal proteins to the underlying cytoskeleton likely contributes to this diffusion barrier based on 4.1B and βII spectrin expression in Caspr-null mice. Together, these results implicate the paranodes as membrane diffusion barriers that regulate targeting to nodes and highlight differences in the assembly of PNS and CNS nodes.SIGNIFICANCE STATEMENT Nodes of Ranvier are essential for effective saltatory conduction along myelinated axons. A major question is how the various axonal proteins that comprise the multimeric nodal complex accumulate at this site. Here we examine how targeting of NF186, a key nodal adhesion molecule, is regulated by the flanking paranodal junctions. We show that the transition from diffusion-trapping to transport-dependent accumulation of NF186 requires the paranodal junctions. We also demonstrate that these junctions are a barrier to diffusion of axonal proteins into the node and highlight differences in PNS and CNS node assembly. These results provide new insights into the mechanism of node assembly and the pathophysiology of neurologic disorders in which impaired paranodal function contributes to clinical disability.
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22
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Smits LM, Schwamborn JC. Midbrain Organoids: A New Tool to Investigate Parkinson's Disease. Front Cell Dev Biol 2020; 8:359. [PMID: 32509785 PMCID: PMC7248385 DOI: 10.3389/fcell.2020.00359] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Accepted: 04/22/2020] [Indexed: 12/12/2022] Open
Abstract
The study of human 3D cell culture models not only bridges the gap between traditional 2D in vitro experiments and in vivo animal models, it also addresses processes that cannot be recapitulated by either of these traditional models. Therefore, it offers an opportunity to better understand complex biology including brain development. The brain organoid technology provides a physiologically relevant context, which holds great potential for its application in modeling neurological diseases. Here, we compare different methods to obtain highly specialized structures that resemble specific features of the human midbrain. Regionally patterned neural stem cells (NSCs) were utilized to derive such human midbrain-specific organoids (hMO). The resulting neural tissue exhibited abundant neurons with midbrain dopaminergic neuron identity, as well as astroglia and oligodendrocyte differentiation. Within the midbrain organoids, neurite myelination, and the formation of synaptic connections were observed. Regular neuronal fire patterning and neural network synchronicity were determined by multielectrode array recordings. In addition to electrophysiologically functional neurons producing and secreting dopamine, responsive neuronal subtypes, such as GABAergic and glutamatergic neurons were also detected. In order to model disorders like Parkinson's disease (PD) in vitro, midbrain organoids carrying a disease specific mutation were derived and compared to healthy control organoids to investigate relevant neurodegenerative pathophysiology. In this way midbrain-specific organoids constitute a powerful tool for human-specific in vitro modeling of neurological disorders with a great potential to be utilized in advanced therapy development.
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23
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Song GJ, Gupta DP, Rahman MH, Park HT, Al Ghouleh I, Bisello A, Lee MG, Park JY, Park HH, Jun JH, Chung KW, Choi BO, Suk K. Loss-of-function of EBP50 is a new cause of hereditary peripheral neuropathy: EBP50 functions in peripheral nerve system. Glia 2020; 68:1794-1809. [PMID: 32077526 DOI: 10.1002/glia.23805] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 02/04/2020] [Accepted: 02/07/2020] [Indexed: 12/12/2022]
Abstract
Finding causative genetic mutations is important in the diagnosis and treatment of hereditary peripheral neuropathies. This study was conducted to find new genes involved in the pathophysiology of hereditary peripheral neuropathy. We identified a new mutation in the EBP50 gene, which is co-segregated with neuropathic phenotypes, including motor and sensory deficit in a family with Charcot-Marie-Tooth disease. EBP50 is known to be important for the formation of microvilli in epithelial cells, and the discovery of this gene mutation allowed us to study the function of EBP50 in the nervous system. EBP50 was strongly expressed in the nodal and paranodal regions of sciatic nerve fibers, where Schwann cell microvilli contact the axolemma, and at the growth tips of primary Schwann cells. In addition, EBP50 expression was decreased in mouse models of peripheral neuropathy. Knockout mice were used to study EBP50 function in the peripheral nervous system. Interestingly motor function deficit and abnormal histology of nerve fibers were observed in EBP50+/- heterozygous mice at 12 months of age, but not 3 months. in vitro studies using Schwann cells showed that NRG1-induced AKT activation and migration were significantly reduced in cells overexpressing the I325V mutant of EBP50 or cells with knocked-down EBP50 expression. In conclusion, we show for the first time that loss of function due to EBP50 gene deficiency or mutation can cause peripheral neuropathy.
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Affiliation(s)
- Gyun Jee Song
- Department of Medical Science, Institute for Bio-Medical Convergence, Catholic Kwandong University, International St. Mary's Hospital, Incheon, Republic of Korea
| | - Deepak Prasad Gupta
- Department of Pharmacology, Brain Science and Engineering Institute, BK21 Plus KNU Biomedical Convergence Program, School of Medicine, Kyungpook National University, Daegu, Republic of Korea
| | - Md Habibur Rahman
- Department of Pharmacology, Brain Science and Engineering Institute, BK21 Plus KNU Biomedical Convergence Program, School of Medicine, Kyungpook National University, Daegu, Republic of Korea
| | - Hwan Tae Park
- Department of Molecular Neuroscience, College of Medicine, Dong-A University, Busan, Republic of Korea
| | - Imad Al Ghouleh
- Division of Cardiology, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Alessandro Bisello
- Department of Pharmacology and Chemical Biology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
| | - Maan-Gee Lee
- Department of Pharmacology, Brain Science and Engineering Institute, BK21 Plus KNU Biomedical Convergence Program, School of Medicine, Kyungpook National University, Daegu, Republic of Korea
| | - Jae-Yong Park
- School of Biosystems and Biomedical Sciences, College of Health Sciences, Korea University, Seoul, Republic of Korea
| | - Hyun Ho Park
- College of Pharmacy, Chung-Ang University, Seoul, Republic of Korea
| | - Jin Hyun Jun
- Department of Senior Healthcare, BK21 Plus Program, Graduate School of Eulji University, Department of Biomedical Laboratory Science, College of Health Science, Eulji University, Seongnam, Republic of Korea
| | - Ki Wha Chung
- Department of Biological Sciences, Kongju National University, Gongju, Republic of Korea
| | - Byung-Ok Choi
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Kyoungho Suk
- Department of Pharmacology, Brain Science and Engineering Institute, BK21 Plus KNU Biomedical Convergence Program, School of Medicine, Kyungpook National University, Daegu, Republic of Korea
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24
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Hartmannsberger B, Doppler K, Stauber J, Schlotter-Weigel B, Young P, Sereda MW, Sommer C. Intraepidermal nerve fibre density as biomarker in Charcot-Marie-Tooth disease type 1A. Brain Commun 2020; 2:fcaa012. [PMID: 32954280 PMCID: PMC7425304 DOI: 10.1093/braincomms/fcaa012] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 01/08/2020] [Accepted: 01/24/2020] [Indexed: 01/03/2023] Open
Abstract
Charcot-Marie-Tooth disease type 1A, caused by a duplication of the gene peripheral myelin protein 22 kDa, is the most frequent subtype of hereditary peripheral neuropathy with an estimated prevalence of 1:5000. Patients suffer from sensory deficits, muscle weakness and foot deformities. There is no treatment approved for this disease. Outcome measures in clinical trials were based mainly on clinical features but did not evaluate the actual nerve damage. In our case-control study, we aimed to provide objective and reproducible outcome measures for future clinical trials. We collected skin samples from 48 patients with Charcot-Marie-Tooth type 1A, 7 patients with chronic inflammatory demyelinating polyneuropathy, 16 patients with small fibre neuropathy and 45 healthy controls. To analyse skin innervation, 40-µm cryosections of glabrous skin taken from the lateral index finger were double-labelled by immunofluorescence. The disease severity of patients with Charcot-Marie-Tooth type 1A was assessed by the Charcot-Marie-Tooth neuropathy version 2 score, which ranged from 3 (mild) to 27 (severe) and correlated with age (P < 0.01, R = 0.4). Intraepidermal nerve fibre density was reduced in patients with Charcot-Marie-Tooth type 1A compared with the healthy control group (P < 0.01) and negatively correlated with disease severity (P < 0.05, R = -0.293). Meissner corpuscle (MC) density correlated negatively with age in patients with Charcot-Marie-Tooth type 1A (P < 0.01, R = -0.45) but not in healthy controls (P = 0.07, R = 0.28). The density of Merkel cells was reduced in patients with Charcot-Marie-Tooth type 1A compared with healthy controls (P < 0.05). Furthermore, in patients with Charcot-Marie-Tooth type 1A, the fraction of denervated Merkel cells was highly increased and correlated with age (P < 0.05, R = 0.37). Analysis of nodes of Ranvier revealed shortened paranodes and a reduced fraction of long nodes in patients compared with healthy controls (both P < 0.001). Langerhans cell density was increased in chronic inflammatory demyelinating polyneuropathy, but not different in Charcot-Marie-Tooth type 1A compared with healthy controls. Our data suggest that intraepidermal nerve fibre density might be used as an outcome measure in Charcot-Marie-Tooth type 1A disease, as it correlates with disease severity. The densities of Meissner corpuscles and Merkel cells might be an additional tool for the evaluation of the disease progression. Analysis of follow-up biopsies will clarify the effects of Charcot-Marie-Tooth type 1A disease progression on cutaneous innervation.
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Affiliation(s)
| | - Kathrin Doppler
- Department of Neurology, University of Würzburg, 97080 Würzburg, Germany
| | - Julia Stauber
- Friedrich-Baur-Institute, Department of Neurology, Ludwig-Maximilians-University of Munich, 80336 Munich, Germany
| | - Beate Schlotter-Weigel
- Friedrich-Baur-Institute, Department of Neurology, Ludwig-Maximilians-University of Munich, 80336 Munich, Germany
| | - Peter Young
- Medical Park Bad Feilnbach Reithofpark, Department of Neurology, 83075 Bad Feilnbach, Germany
| | - Michael W Sereda
- Department of Clinical Neurophysiology, University Medical Center Göttingen (UMG), 37075 Göttingen, Germany
| | - Claudia Sommer
- Department of Neurology, University of Würzburg, 97080 Würzburg, Germany
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25
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He J, Guo L, Lin S, Chen W, Xu G, Cai B, Xu L, Hong J, Qiu L, Wang N, Chen W. ATP1A1mutations cause intermediate Charcot‐Marie‐Tooth disease. Hum Mutat 2019; 40:2334-2343. [DOI: 10.1002/humu.23886] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 06/18/2019] [Accepted: 07/30/2019] [Indexed: 12/26/2022]
Affiliation(s)
- Jin He
- Department of Neurology and Institute of Neurology, First Affiliated HospitalFujian Medical University Fuzhou China
- Fujian Key Laboratory of Molecular NeurologyFujian Medical University Fuzhou China
| | - Lingling Guo
- Department of Neurology and Institute of Neurology, First Affiliated HospitalFujian Medical University Fuzhou China
| | - Shan Lin
- Department of Neurology and Institute of Neurology, First Affiliated HospitalFujian Medical University Fuzhou China
| | - Wenfeng Chen
- Institute of Life SciencesFuzhou University Fuzhou China
| | - Guorong Xu
- Department of Neurology and Institute of Neurology, First Affiliated HospitalFujian Medical University Fuzhou China
| | - Bin Cai
- Department of Neurology and Institute of Neurology, First Affiliated HospitalFujian Medical University Fuzhou China
- Fujian Key Laboratory of Molecular NeurologyFujian Medical University Fuzhou China
| | - Liuqing Xu
- Department of Neurology and Institute of Neurology, First Affiliated HospitalFujian Medical University Fuzhou China
| | - Jingmei Hong
- Department of Neurology and Institute of Neurology, First Affiliated HospitalFujian Medical University Fuzhou China
| | - Liangliang Qiu
- Department of Neurology and Institute of Neurology, First Affiliated HospitalFujian Medical University Fuzhou China
| | - Ning Wang
- Department of Neurology and Institute of Neurology, First Affiliated HospitalFujian Medical University Fuzhou China
- Fujian Key Laboratory of Molecular NeurologyFujian Medical University Fuzhou China
| | - Wanjin Chen
- Department of Neurology and Institute of Neurology, First Affiliated HospitalFujian Medical University Fuzhou China
- Fujian Key Laboratory of Molecular NeurologyFujian Medical University Fuzhou China
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26
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Krishnaswamy VR, Benbenishty A, Blinder P, Sagi I. Demystifying the extracellular matrix and its proteolytic remodeling in the brain: structural and functional insights. Cell Mol Life Sci 2019; 76:3229-3248. [PMID: 31197404 PMCID: PMC11105229 DOI: 10.1007/s00018-019-03182-6] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 05/29/2019] [Accepted: 05/31/2019] [Indexed: 12/29/2022]
Abstract
The extracellular matrix (ECM) plays diverse roles in several physiological and pathological conditions. In the brain, the ECM is unique both in its composition and in functions. Furthermore, almost all the cells in the central nervous system contribute to different aspects of this intricate structure. Brain ECM, enriched with proteoglycans and other small proteins, aggregate into distinct structures around neurons and oligodendrocytes. These special structures have cardinal functions in the normal functioning of the brain, such as learning, memory, and synapse regulation. In this review, we have compiled the current knowledge about the structure and function of important ECM molecules in the brain and their proteolytic remodeling by matrix metalloproteinases and other enzymes, highlighting the special structures they form. In particular, the proteoglycans in brain ECM, which are essential for several vital functions, are emphasized in detail.
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Affiliation(s)
| | - Amit Benbenishty
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
| | - Pablo Blinder
- Neurobiology, Biochemistry and Biophysics School, Tel Aviv University, Tel Aviv, Israel
- Sagol School for Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Irit Sagi
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel.
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27
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Manso C, Querol L, Lleixà C, Poncelet M, Mekaouche M, Vallat JM, Illa I, Devaux JJ. Anti-Neurofascin-155 IgG4 antibodies prevent paranodal complex formation in vivo. J Clin Invest 2019; 129:2222-2236. [PMID: 30869655 DOI: 10.1172/jci124694] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Neurofascin-155 (Nfasc155) is an essential glial cell adhesion molecule expressed in paranodal septate-like junctions of peripheral and central myelinated axons. The genetic deletion of Nfasc155 results in the loss of septate-like junctions and in conduction slowing. In humans, IgG4 antibodies against Nfasc155 are implicated in the pathogenesis of chronic inflammatory demyelinating polyneuropathy (CIDP). These antibodies are associated with an aggressive onset, a refractoriness to intravenous immunoglobulin, and tremor of possible cerebellar origin. Here, we examined the pathogenic effects of patient-derived anti-Nfasc155 IgG4. These antibodies did not inhibit the ability of Nfasc155 to complex with its axonal partners contactin-1/CASPR1 or induce target internalization. Passive transfer experiments revealed that IgG4 antibodies target Nfasc155 on Schwann cell surface, and diminished Nfasc155 protein levels and prevented paranodal complex formation in neonatal animals. In adult animals, chronic intrathecal infusions of antibodies also induced the loss of Nfasc155 and of paranodal specialization and resulted in conduction alterations in motor nerves. These results indicate that anti-Nfasc155 IgG4 perturb conduction in absence of demyelination, validating the existence of paranodopathy. These results also shed light on the mechanisms regulating protein insertion at paranodes.
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Affiliation(s)
- Constance Manso
- Aix Marseille Université, CNRS, CRN2M-UMR7286, Marseille, France.,Université de Bordeaux, Interdisciplinary Institute for Neuroscience, UMR5297, Bordeaux, France
| | - Luis Querol
- Neuromuscular Diseases Unit, Hospital de la Santa Creu i Sant Pau, Universitat Autónoma de Barcelona, Barcelona, Spain.,Centro para la Investigación en Red en Enfermedades Raras (CIBERER), Madrid, Spain
| | - Cinta Lleixà
- Neuromuscular Diseases Unit, Hospital de la Santa Creu i Sant Pau, Universitat Autónoma de Barcelona, Barcelona, Spain.,Centro para la Investigación en Red en Enfermedades Raras (CIBERER), Madrid, Spain
| | - Mallory Poncelet
- Institute for Neurosciences of Montpellier, INSERM U1051, Montpellier University, Hopital Gui de Chauliac, Montpellier, France
| | - Mourad Mekaouche
- Aix Marseille Université, CNRS, CRN2M-UMR7286, Marseille, France.,Aix Marseille Université, CNRS, INP UMR7051, Marseille, France
| | - Jean-Michel Vallat
- National Reference Center for "rare peripheral neuropathies" and Department of Neurology, University Hospital, Limoges, France
| | - Isabel Illa
- Neuromuscular Diseases Unit, Hospital de la Santa Creu i Sant Pau, Universitat Autónoma de Barcelona, Barcelona, Spain.,Centro para la Investigación en Red en Enfermedades Raras (CIBERER), Madrid, Spain
| | - Jérôme J Devaux
- Aix Marseille Université, CNRS, CRN2M-UMR7286, Marseille, France.,Institute for Neurosciences of Montpellier, INSERM U1051, Montpellier University, Hopital Gui de Chauliac, Montpellier, France
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28
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Chatterjee M, Schild D, Teunissen CE. Contactins in the central nervous system: role in health and disease. Neural Regen Res 2019; 14:206-216. [PMID: 30530999 PMCID: PMC6301169 DOI: 10.4103/1673-5374.244776] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 09/17/2018] [Indexed: 01/06/2023] Open
Abstract
Contactins are a group of cell adhesion molecules that are mainly expressed in the brain and play pivotal roles in the organization of axonal domains, axonal guidance, neuritogenesis, neuronal development, synapse formation and plasticity, axo-glia interactions and neural regeneration. Contactins comprise a family of six members. Their absence leads to malformed axons and impaired nerve conduction. Contactin mediated protein complex formation is critical for the organization of the axon in early central nervous system development. Mutations and differential expression of contactins have been identified in neuro-developmental or neurological disorders. Taken together, contactins are extensively studied in the context of nervous system development. This review summarizes the physiological roles of all six members of the Contactin family in neurodevelopment as well as their involvement in neurological/neurodevelopmental disorders.
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Affiliation(s)
- Madhurima Chatterjee
- Amsterdam UMC, VU University Medical Center, Department of Clinical Chemistry, Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Detlev Schild
- Institute of Neurophysiology and Cellular Biophysics, University of Göttingen, Göttingen, Germany
- DFG Research Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), University of Göttingen, Göttingen, Germany
- DFG Excellence Cluster 171, University of Göttingen, Göttingen, Germany
| | - Charlotte E. Teunissen
- Amsterdam UMC, VU University Medical Center, Department of Clinical Chemistry, Amsterdam Neuroscience, Amsterdam, The Netherlands
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29
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Abstract
Important advances in our understanding of oligodendrocyte precursor cell biology and differentiation have stemmed from in vitro experiments using cultures of isolated primary oligodendrocyte precursor cells. To examine the process of myelination in the final stages of oligodendrocyte development, experimental systems have previously been limited to models utilizing neurons. Recent advances in three-dimensional culture systems, however, have opened the possibility to observe myelin sheath formation with only one cell type, the oligodendrocyte precursor cell. In this chapter, such a method is described for examining oligodendrocyte myelin sheath formation with isolated oligodendrocytes in the absence of neurons. This assay is ideal for gaining mechanistic insight into oligodendrocyte-specific regulation of myelin sheath formation. Oligodendrocyte heterogeneity can be readily assessed, determining whether different oligodendrocyte sources influence myelin sheath formation. As well, the direct impact of both physical and molecular cues on oligodendrocytes can be determined in this defined system. This assay extends the capability of two-dimensional oligodendrocyte cultures, permitting post-differentiation analysis of myelinating oligodendrocytes, the number of sheaths formed by individual oligodendrocytes, as well as the lengths of myelin sheaths formed.
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Affiliation(s)
- Marie E Bechler
- MRC Centre for Regenerative Medicine, MS Society Edinburgh Centre for MS Research, The University of Edinburgh, Edinburgh, UK.
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30
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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: 70] [Impact Index Per Article: 11.7] [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.
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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
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31
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Zagajewska K, Piątkowska M, Goryca K, Bałabas A, Kluska A, Paziewska A, Pośpiech E, Grabska-Liberek I, Hennig EE. GWAS links variants in neuronal development and actin remodeling related loci with pseudoexfoliation syndrome without glaucoma. Exp Eye Res 2018; 168:138-148. [DOI: 10.1016/j.exer.2017.12.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 12/05/2017] [Accepted: 12/20/2017] [Indexed: 01/13/2023]
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32
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Abstract
IgG4 autoimmune diseases are characterized by the presence of antigen-specific autoantibodies of the IgG4 subclass and contain well-characterized diseases such as muscle-specific kinase myasthenia gravis, pemphigus, and thrombotic thrombocytopenic purpura. In recent years, several new diseases were identified, and by now 14 antigens targeted by IgG4 autoantibodies have been described. The IgG4 subclass is considered immunologically inert and functionally monovalent due to structural differences compared to other IgG subclasses. IgG4 usually arises after chronic exposure to antigen and competes with other antibody species, thus "blocking" their pathogenic effector mechanisms. Accordingly, in the context of IgG4 autoimmunity, the pathogenicity of IgG4 is associated with blocking of enzymatic activity or protein-protein interactions of the target antigen. Pathogenicity of IgG4 autoantibodies has not yet been systematically analyzed in IgG4 autoimmune diseases. Here, we establish a modified classification system based on Witebsky's postulates to determine IgG4 pathogenicity in IgG4 autoimmune diseases, review characteristics and pathogenic mechanisms of IgG4 in these disorders, and also investigate the contribution of other antibody entities to pathophysiology by additional mechanisms. As a result, three classes of IgG4 autoimmune diseases emerge: class I where IgG4 pathogenicity is validated by the use of subclass-specific autoantibodies in animal models and/or in vitro models of pathogenicity; class II where IgG4 pathogenicity is highly suspected but lack validation by the use of subclass specific antibodies in in vitro models of pathogenicity or animal models; and class III with insufficient data or a pathogenic mechanism associated with multivalent antigen binding. Five out of the 14 IgG4 antigens were validated as class I, five as class II, and four as class III. Antibodies of other IgG subclasses or immunoglobulin classes were present in several diseases and could contribute additional pathogenic mechanisms.
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Affiliation(s)
- Inga Koneczny
- Institute of Neurology, Medical University of Vienna, Vienna, Austria
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33
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Tricaud N. Myelinating Schwann Cell Polarity and Mechanically-Driven Myelin Sheath Elongation. Front Cell Neurosci 2018; 11:414. [PMID: 29354031 PMCID: PMC5760505 DOI: 10.3389/fncel.2017.00414] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 12/11/2017] [Indexed: 11/13/2022] Open
Abstract
Myelin sheath geometry, encompassing myelin sheath thickness relative to internodal length, is critical to optimize nerve conduction velocity and these parameters are carefully adjusted by the myelinating cells in mammals. In the central nervous system these adjustments could regulate neuronal activities while in the peripheral nervous system they lead to the optimization and the reliability of the nerve conduction velocity. However, the physiological and cellular mechanisms that underlie myelin sheath geometry regulation are not yet fully elucidated. In peripheral nerves the myelinating Schwann cell uses several molecular mechanisms to reach and maintain the correct myelin sheath geometry, such that myelin sheath thickness and internodal length are regulated independently. One of these mechanisms is the epithelial-like cell polarization process that occurs during the early phases of the myelin biogenesis. Epithelial cell polarization factors are known to control cell size and morphology in invertebrates and mammals making these processes critical in the organogenesis. Correlative data indicate that internodal length is regulated by postnatal body growth that elongates peripheral nerves in mammals. In addition, the mechanical stretching of peripheral nerves in adult animals shows that myelin sheath length can be increased by mechanical cues. Recent results describe the important role of YAP/TAZ co-transcription factors during Schwann cell myelination and their functions have linked to the mechanotransduction through the HIPPO pathway and the epithelial polarity factor Crb3. In this review the molecular mechanisms that govern mechanically-driven myelin sheath elongation and how a Schwann cell can modulate internodal myelin sheath length, independent of internodal thickness, will be discussed regarding these recent data. In addition, the potential relevance of these mechanosensitive mechanisms in peripheral pathologies will be highlighted.
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Affiliation(s)
- Nicolas Tricaud
- Institut National de la Santé et de la Recherche Médicale, Institut des Neurosciences de Montpellier, Université de Montpellier, Montpellier, France
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34
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Fehmi J, Scherer SS, Willison HJ, Rinaldi S. Nodes, paranodes and neuropathies. J Neurol Neurosurg Psychiatry 2018; 89:61-71. [PMID: 28819062 DOI: 10.1136/jnnp-2016-315480] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 06/28/2017] [Accepted: 06/29/2017] [Indexed: 12/13/2022]
Abstract
This review summarises recent evidence supporting the involvement of the specialised nodal and perinodal domains (the paranode and juxtaparanode) of myelinated axons in the pathology of acquired, inflammatory, peripheral neuropathies.The identification of new target antigens in the inflammatory neuropathies heralds a revolution in diagnosis, and has already begun to inform increasingly targeted and individualised therapies. Rapid progress in our basic understanding of the highly specialised nodal regions of peripheral nerves serves to strengthen the links between their unique microstructural identities, functions and pathologies. In this context, the detection of autoantibodies directed against nodal and perinodal targets is likely to be of increasing clinical importance. Antiganglioside antibodies have long been used in clinical practice as diagnostic serum biomarkers, and associate with specific clinical variants but not to the common forms of either acute or chronic demyelinating autoimmune neuropathy. It is now apparent that antibodies directed against several region-specific cell adhesion molecules, including neurofascin, contactin and contactin-associated protein, can be linked to phenotypically distinct peripheral neuropathies. Importantly, the immunological characteristics of these antibodies facilitate the prediction of treatment responsiveness.
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Affiliation(s)
- Janev Fehmi
- Department of Neurology, Southmead Hospital, Bristol, UK
| | - Steven S Scherer
- Department of Neurology, The Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Hugh J Willison
- Department of Neuroimmunology, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Simon Rinaldi
- Department of Clinical Neurosciences, West Wing, John Radcliffe Hospital, Oxford, UK
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35
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Spaiardi P, Tavazzani E, Manca M, Milesi V, Russo G, Prigioni I, Marcotti W, Magistretti J, Masetto S. An allosteric gating model recapitulates the biophysical properties of I K,L expressed in mouse vestibular type I hair cells. J Physiol 2017; 595:6735-6750. [PMID: 28862328 PMCID: PMC5663832 DOI: 10.1113/jp274202] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Accepted: 08/30/2017] [Indexed: 12/11/2022] Open
Abstract
Key points Vestibular type I and type II hair cells and their afferent fibres send information to the brain regarding the position and movement of the head. The characteristic feature of type I hair cells is the expression of a low‐voltage‐activated outward rectifying K+ current, IK,L, whose biophysical properties and molecular identity are still largely unknown. In vitro, the afferent nerve calyx surrounding type I hair cells causes unstable intercellular K+ concentrations, altering the biophysical properties of IK,L. We found that in the absence of the calyx, IK,L in type I hair cells exhibited unique biophysical activation properties, which were faithfully reproduced by an allosteric channel gating scheme. These results form the basis for a molecular and pharmacological identification of IK,L.
Abstract Type I and type II hair cells are the sensory receptors of the mammalian vestibular epithelia. Type I hair cells are characterized by their basolateral membrane being enveloped in a single large afferent nerve terminal, named the calyx, and by the expression of a low‐voltage‐activated outward rectifying K+ current, IK,L. The biophysical properties and molecular profile of IK,L are still largely unknown. By using the patch‐clamp whole‐cell technique, we examined the voltage‐ and time‐dependent properties of IK,L in type I hair cells of the mouse semicircular canal. We found that the biophysical properties of IK,L were affected by an unstable K+ equilibrium potential (VeqK+). Both the outward and inward K+ currents shifted VeqK+ consistent with K+ accumulation or depletion, respectively, in the extracellular space, which we attributed to a residual calyx attached to the basolateral membrane of the hair cells. We therefore optimized the hair cell dissociation protocol in order to isolate mature type I hair cells without their calyx. In these cells, the uncontaminated IK,L showed a half‐activation at –79.6 mV and a steep voltage dependence (2.8 mV). IK,L also showed complex activation and deactivation kinetics, which we faithfully reproduced by an allosteric channel gating scheme where the channel is able to open from all (five) closed states. The ‘early’ open states substantially contribute to IK,L activation at negative voltages. This study provides the first complete description of the ‘native’ biophysical properties of IK,L in adult mouse vestibular type I hair cells. Vestibular type I and type II hair cells and their afferent fibres send information to the brain regarding the position and movement of the head. The characteristic feature of type I hair cells is the expression of a low‐voltage‐activated outward rectifying K+ current, IK,L, whose biophysical properties and molecular identity are still largely unknown. In vitro, the afferent nerve calyx surrounding type I hair cells causes unstable intercellular K+ concentrations, altering the biophysical properties of IK,L. We found that in the absence of the calyx, IK,L in type I hair cells exhibited unique biophysical activation properties, which were faithfully reproduced by an allosteric channel gating scheme. These results form the basis for a molecular and pharmacological identification of IK,L.
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Affiliation(s)
- Paolo Spaiardi
- Department of Brain and Behavioural Sciences, University of Pavia, Pavia, 27100, Italy
| | - Elisa Tavazzani
- Department of Brain and Behavioural Sciences, University of Pavia, Pavia, 27100, Italy
| | - Marco Manca
- Department of Brain and Behavioural Sciences, University of Pavia, Pavia, 27100, Italy
| | - Veronica Milesi
- Instituto de Estudios Inmunológios y Fisiopatológicos (IIFP) - CONICET, Universidad Nacional de La Plata, La Plata, 1900, Argentina
| | - Giancarlo Russo
- Department of Brain and Behavioural Sciences, University of Pavia, Pavia, 27100, Italy
| | - Ivo Prigioni
- Department of Brain and Behavioural Sciences, University of Pavia, Pavia, 27100, Italy
| | - Walter Marcotti
- Department of Biomedical Science, University of Sheffield, Sheffield, S10 2TN, UK
| | - Jacopo Magistretti
- Department of Biology and Biotechnology, University of Pavia, Pavia, 27100, Italy
| | - Sergio Masetto
- Department of Brain and Behavioural Sciences, University of Pavia, Pavia, 27100, Italy
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36
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Abstract
In this issue of Neuron, Redmond et al. (2016) identify junction adhesion molecule 2 (JAM2) as an inhibitor of somatodendritic myelination in spinal cord neurons, thereby elucidating how myelin forms on axons but avoids dendrites and cell bodies.
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Affiliation(s)
- Rose M Follis
- Department of Biochemistry, Vanderbilt Brain Institute, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Bruce D Carter
- Department of Biochemistry, Vanderbilt Brain Institute, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
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37
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Derivation of Human Midbrain-Specific Organoids from Neuroepithelial Stem Cells. Stem Cell Reports 2017; 8:1144-1154. [PMID: 28416282 PMCID: PMC5425618 DOI: 10.1016/j.stemcr.2017.03.010] [Citation(s) in RCA: 261] [Impact Index Per Article: 37.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 03/10/2017] [Accepted: 03/10/2017] [Indexed: 02/06/2023] Open
Abstract
Research on human brain development and neurological diseases is limited by the lack of advanced experimental in vitro models that truly recapitulate the complexity of the human brain. Here, we describe a robust human brain organoid system that is highly specific to the midbrain derived from regionally patterned neuroepithelial stem cells. These human midbrain organoids contain spatially organized groups of dopaminergic neurons, which make them an attractive model for the study of Parkinson's disease. Midbrain organoids are characterized in detail for neuronal, astroglial, and oligodendrocyte differentiation. Furthermore, we show the presence of synaptic connections and electrophysiological activity. The complexity of this model is further highlighted by the myelination of neurites. The present midbrain organoid system has the potential to be used for advanced in vitro disease modeling and therapy development.
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38
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Dynamic Control of Synaptic Adhesion and Organizing Molecules in Synaptic Plasticity. Neural Plast 2017; 2017:6526151. [PMID: 28255461 PMCID: PMC5307005 DOI: 10.1155/2017/6526151] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Accepted: 12/13/2016] [Indexed: 12/13/2022] Open
Abstract
Synapses play a critical role in establishing and maintaining neural circuits, permitting targeted information transfer throughout the brain. A large portfolio of synaptic adhesion/organizing molecules (SAMs) exists in the mammalian brain involved in synapse development and maintenance. SAMs bind protein partners, forming trans-complexes spanning the synaptic cleft or cis-complexes attached to the same synaptic membrane. SAMs play key roles in cell adhesion and in organizing protein interaction networks; they can also provide mechanisms of recognition, generate scaffolds onto which partners can dock, and likely take part in signaling processes as well. SAMs are regulated through a portfolio of different mechanisms that affect their protein levels, precise localization, stability, and the availability of their partners at synapses. Interaction of SAMs with their partners can further be strengthened or weakened through alternative splicing, competing protein partners, ectodomain shedding, or astrocytically secreted factors. Given that numerous SAMs appear altered by synaptic activity, in vivo, these molecules may be used to dynamically scale up or scale down synaptic communication. Many SAMs, including neurexins, neuroligins, cadherins, and contactins, are now implicated in neuropsychiatric and neurodevelopmental diseases, such as autism spectrum disorder, schizophrenia, and bipolar disorder and studying their molecular mechanisms holds promise for developing novel therapeutics.
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39
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Ultrastructural anatomy of nodes of Ranvier in the peripheral nervous system as revealed by STED microscopy. Proc Natl Acad Sci U S A 2016; 114:E191-E199. [PMID: 28003466 DOI: 10.1073/pnas.1619553114] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We used stimulated emission depletion (STED) superresolution microscopy to analyze the nanoscale organization of 12 glial and axonal proteins at the nodes of Ranvier of teased sciatic nerve fibers. Cytoskeletal proteins of the axon (betaIV spectrin, ankyrin G) exhibit a high degree of one-dimensional longitudinal order at nodal gaps. In contrast, axonal and glial nodal adhesion molecules [neurofascin-186, neuron glial-related cell adhesion molecule (NrCAM)] can arrange in a more complex, 2D hexagonal-like lattice but still feature a ∼190-nm periodicity. Such a lattice-like organization is also found for glial actin. Sodium and potassium channels exhibit a one-dimensional periodicity, with the Nav channels appearing to have a lower degree of organization. At paranodes, both axonal proteins (betaII spectrin, Caspr) and glial proteins (neurofascin-155, ankyrin B) form periodic quasi-one-dimensional arrangements, with a high degree of interdependence between the position of the axonal and the glial proteins. The results indicate the presence of mechanisms that finely align the cytoskeleton of the axon with the one of the Schwann cells, both at paranodal junctions (with myelin loops) and at nodal gaps (with microvilli). Taken together, our observations reveal the importance of the lateral organization of proteins at the nodes of Ranvier and pave the way for deeper investigations of the molecular ultrastructural mechanisms involved in action potential propagation, the formation of the nodes, axon-glia interactions, and demyelination diseases.
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40
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Nizon M, Cogne B, Vallat JM, Joubert M, Liet JM, Simon L, Vincent M, Küry S, Boisseau P, Schmitt S, Mercier S, Bénéteau C, Larrose C, Coste M, Latypova X, Péréon Y, Mussini JM, Bézieau S, Isidor B. Two novel variants in CNTNAP1 in two siblings presenting with congenital hypotonia and hypomyelinating neuropathy. Eur J Hum Genet 2016; 25:150-152. [PMID: 27782105 DOI: 10.1038/ejhg.2016.142] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Revised: 08/29/2016] [Accepted: 09/20/2016] [Indexed: 01/06/2023] Open
Abstract
Homozygous frameshift variants in CNTNAP1 have recently been reported in patients with arthrogryposis and abnormal axon myelination. In two brothers with severe congenital hypotonia and foot deformities, we identified compound heterozygous variants in CNTNAP1, reporting the first causative missense variant, p.(Cys323Arg). Motor nerve conductions were markedly decreased. Nerve microscopical lesions confirmed a severe hypomyelinating process and showed loss of attachment sites of the myelin loops on the axons, which could be a characteristic of Caspr loss-of-function. We discuss the pathophysiology of the myelination process and we propose to consider this disorder as a congenital hypomyelinating neuropathy.
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Affiliation(s)
| | | | - Jean-Michel Vallat
- Centre de référence « neuropathies périphériques rares », service de Neurologie, CHU Limoges, France
| | | | - Jean-Michel Liet
- Service de réanimation pédiatrique, Hôpital Mère Enfants, Nantes, France
| | - Laure Simon
- Service de réanimation néonatale, Hôpital Mère Enfants, Nantes, France
| | - Marie Vincent
- Service de Génétique Médicale, CHU Hôtel Dieu, France
| | | | | | | | | | | | | | | | | | - Yann Péréon
- Service d'explorations fonctionnelles, CHU Hôtel Dieu, Nantes, France
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41
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Griggs RB, Yermakov LM, Susuki K. Formation and disruption of functional domains in myelinated CNS axons. Neurosci Res 2016; 116:77-87. [PMID: 27717670 DOI: 10.1016/j.neures.2016.09.010] [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: 08/31/2016] [Revised: 09/19/2016] [Accepted: 09/23/2016] [Indexed: 12/15/2022]
Abstract
Communication in the central nervous system (CNS) occurs through initiation and propagation of action potentials at excitable domains along axons. Action potentials generated at the axon initial segment (AIS) are regenerated at nodes of Ranvier through the process of saltatory conduction. Proper formation and maintenance of the molecular structure at the AIS and nodes are required for sustaining conduction fidelity. In myelinated CNS axons, paranodal junctions between the axolemma and myelinating oligodendrocytes delineate nodes of Ranvier and regulate the distribution and localization of specialized functional elements, such as voltage-gated sodium channels and mitochondria. Disruption of excitable domains and altered distribution of functional elements in CNS axons is associated with demyelinating diseases such as multiple sclerosis, and is likely a mechanism common to other neurological disorders. This review will provide a brief overview of the molecular structure of the AIS and nodes of Ranvier, as well as the distribution of mitochondria in myelinated axons. In addition, this review highlights important structural and functional changes within myelinated CNS axons that are associated with neurological dysfunction.
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Affiliation(s)
- Ryan B Griggs
- Department of Neuroscience, Cell Biology, and Physiology, Boonshoft School of Medicine, Wright State University, Dayton, OH, United States
| | - Leonid M Yermakov
- Department of Neuroscience, Cell Biology, and Physiology, Boonshoft School of Medicine, Wright State University, Dayton, OH, United States
| | - Keiichiro Susuki
- Department of Neuroscience, Cell Biology, and Physiology, Boonshoft School of Medicine, Wright State University, Dayton, OH, United States.
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42
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Schneider S, Gruart A, Grade S, Zhang Y, Kröger S, Kirchhoff F, Eichele G, Delgado García JM, Dimou L. Decrease in newly generated oligodendrocytes leads to motor dysfunctions and changed myelin structures that can be rescued by transplanted cells. Glia 2016; 64:2201-2218. [PMID: 27615452 DOI: 10.1002/glia.23055] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 08/11/2016] [Accepted: 08/22/2016] [Indexed: 11/09/2022]
Abstract
NG2-glia in the adult brain are known to proliferate and differentiate into mature and myelinating oligodendrocytes throughout lifetime. However, the role of these newly generated oligodendrocytes in the adult brain still remains little understood. Here we took advantage of the Sox10-iCreERT2 x CAG-eGFP x Esco2fl/fl mouse line in which we can specifically ablate proliferating NG2-glia in adult animals. Surprisingly, we observed that the generation of new oligodendrocytes in the adult brain was severely affected, although the number of NG2-glia remained stable due to the enhanced proliferation of non-recombined cells. This lack of oligodendrogenesis led to the elongation of the nodes of Ranvier as well as the associated paranodes, which could be locally rescued by myelinating oligodendrocytes differentiated from transplanted NG2-glia deriving from wildtype mice. Repetitive measurements of conduction velocity in the corpus callosum of awake animals revealed a progressive deceleration specifically in the mice lacking adult oligodendrogenesis that resulted in progressive motor deficits. In summary, here we demonstrated for the first time that axon function is not only controlled by the reliable organization of myelin, but also requires a dynamic and continuous generation of new oligodendrocytes in the adult brain. GLIA 2016;64:2201-2218.
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Affiliation(s)
- Sarah Schneider
- Physiological Genomics, Biomedical Center, Ludwig-Maximilians University, Munich, Germany.,Institute of Stem Cell Research, Helmholtz Zentrum, Neuherberg, Germany.,Graduate School of Systemic Neurosciences, Ludwig-Maximilians University, Munich, Germany
| | - Agnès Gruart
- División de Neurosciencias, Universidad Pablo de Olavide, Seville, Spain
| | - Sofia Grade
- Physiological Genomics, Biomedical Center, Ludwig-Maximilians University, Munich, Germany.,Institute of Stem Cell Research, Helmholtz Zentrum, Neuherberg, Germany
| | - Yina Zhang
- Physiological Genomics, Biomedical Center, Ludwig-Maximilians University, Munich, Germany
| | - Stephan Kröger
- Physiological Genomics, Biomedical Center, Ludwig-Maximilians University, Munich, Germany
| | - Frank Kirchhoff
- Molecular Physiology, Center of Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland, Homburg, Germany
| | - Gregor Eichele
- Department of Genes and Behavior, MPI for Biophysical Chemistry, Göttingen, Germany
| | | | - Leda Dimou
- Physiological Genomics, Biomedical Center, Ludwig-Maximilians University, Munich, Germany. .,Institute of Stem Cell Research, Helmholtz Zentrum, Neuherberg, Germany. .,Graduate School of Systemic Neurosciences, Ludwig-Maximilians University, Munich, Germany. .,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.
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43
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Lu Z, Reddy MVVVS, Liu J, Kalichava A, Liu J, Zhang L, Chen F, Wang Y, Holthauzen LMF, White MA, Seshadrinathan S, Zhong X, Ren G, Rudenko G. Molecular Architecture of Contactin-associated Protein-like 2 (CNTNAP2) and Its Interaction with Contactin 2 (CNTN2). J Biol Chem 2016; 291:24133-24147. [PMID: 27621318 DOI: 10.1074/jbc.m116.748236] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 09/02/2016] [Indexed: 11/06/2022] Open
Abstract
Contactin-associated protein-like 2 (CNTNAP2) is a large multidomain neuronal adhesion molecule implicated in a number of neurological disorders, including epilepsy, schizophrenia, autism spectrum disorder, intellectual disability, and language delay. We reveal here by electron microscopy that the architecture of CNTNAP2 is composed of a large, medium, and small lobe that flex with respect to each other. Using epitope labeling and fragments, we assign the F58C, L1, and L2 domains to the large lobe, the FBG and L3 domains to the middle lobe, and the L4 domain to the small lobe of the CNTNAP2 molecular envelope. Our data reveal that CNTNAP2 has a very different architecture compared with neurexin 1α, a fellow member of the neurexin superfamily and a prototype, suggesting that CNTNAP2 uses a different strategy to integrate into the synaptic protein network. We show that the ectodomains of CNTNAP2 and contactin 2 (CNTN2) bind directly and specifically, with low nanomolar affinity. We show further that mutations in CNTNAP2 implicated in autism spectrum disorder are not segregated but are distributed over the whole ectodomain. The molecular shape and dimensions of CNTNAP2 place constraints on how CNTNAP2 integrates in the cleft of axo-glial and neuronal contact sites and how it functions as an organizing and adhesive molecule.
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Affiliation(s)
- Zhuoyang Lu
- From the Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720.,the Center for Mitochondrial Biology and Medicine, Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology and Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China
| | - M V V V Sekhar Reddy
- the Department of Pharmacology and Toxicology.,the Sealy Center for Structural Biology and Molecular Biophysics and
| | - Jianfang Liu
- From the Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720
| | - Ana Kalichava
- the Department of Pharmacology and Toxicology.,the Sealy Center for Structural Biology and Molecular Biophysics and
| | - Jiankang Liu
- the Center for Mitochondrial Biology and Medicine, Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology and Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China
| | - Lei Zhang
- From the Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720
| | - Fang Chen
- the University of Michigan, Ann Arbor, Michigan 48109
| | - Yun Wang
- the University of Michigan, Ann Arbor, Michigan 48109
| | | | - Mark A White
- the Sealy Center for Structural Biology and Molecular Biophysics and.,the Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, Texas 77555, and
| | - Suchithra Seshadrinathan
- the Department of Pharmacology and Toxicology.,the Sealy Center for Structural Biology and Molecular Biophysics and
| | - Xiaoying Zhong
- the Department of Pharmacology and Toxicology.,the Sealy Center for Structural Biology and Molecular Biophysics and
| | - Gang Ren
- From the Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720,
| | - Gabby Rudenko
- the Department of Pharmacology and Toxicology, .,the Sealy Center for Structural Biology and Molecular Biophysics and
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44
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Manso C, Querol L, Mekaouche M, Illa I, Devaux JJ. Contactin-1 IgG4 antibodies cause paranode dismantling and conduction defects. Brain 2016; 139:1700-12. [PMID: 27017186 DOI: 10.1093/brain/aww062] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Accepted: 01/28/2016] [Indexed: 12/20/2022] Open
Abstract
Paranodal axoglial junctions formed by the association of contactin-1, contactin-associated protein 1, and neurofascin-155, play important functions in nerve impulse propagation along myelinated axons. Autoantibodies to contactin-1 and neurofascin-155 define chronic inflammatory demyelinating polyradiculoneuropathy subsets of patients with specific clinical features. These autoantibodies are mostly of the IgG4 isotype, but their pathogenicity has not been proven. Here, we investigated the mechanisms how IgG subclasses to contactin-1 affect conduction. We show that purified anti-contactin-1 IgG1 and IgG4 bind to paranodes. To determine whether these isotypes can pass the paranodal barrier, we incubated isolated sciatic nerves with the purified antibody or performed intraneural injections. We found that IgG4 diffused into the paranodal regions in vitro or after intraneural injections. IgG4 infiltration was slow and progressive. In 24 h, IgG4 accessed the paranode borders near the nodal lumen, and completely fill the paranodal segments by 3 days. By contrast, control IgG, anti-contactin-1 IgG1, or even anti-contactin-associated-protein-2 IgG4 did not pass the paranodal barrier. To determine whether chronic exposure to these antibodies is pathogenic, we passively transferred anti-contactin-1 IgG1 and IgG4 into Lewis rats immunized with P2 peptide. IgG4 to contactin-1, but not IgG1, induced progressive clinical deteriorations combined with gait ataxia. No demyelination, axonal degeneration, or immune infiltration were observed. Instead, these animals presented a selective loss of the paranodal specialization in motor neurons characterized by the disappearance of the contactin-associated protein 1/contactin-1/neurofascin-155 complex at paranodes. Paranode destruction did not affect nodal specialization, but resulted in a moderate node lengthening. The sensory nerves and dorsal root ganglion were not affected in these animals. Electrophysiological examination further supported these results and revealed strong nerve activity loss affecting predominantly small diameter or slow conducting motor axons. These deficits partly matched with those found in patients: proximal motor involvement, gait ataxia, and a demyelinating neuropathy that showed early axonal features. The animal model thus seemed to replicate the early deteriorations in these patients and pointed out that paranodal loss in mature fibres results in conduction defects, but not conduction slowing. Our findings indicate that IgG4 directed against contactin-1 are pathogenic and are reliable biomarkers of a specific subset of chronic inflammatory demyelinating polyneuropathy patients. These antibodies appear to loosen the paranodal barrier, thereby favouring antibody progression and causing paranodal collapse.
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Affiliation(s)
- Constance Manso
- Aix-Marseille Université, CNRS, CRN2M-UMR7286, Marseille, France
| | - Luis Querol
- Neuromuscular Diseases Unit, Hospital de la Santa Creu i Sant Pau, Universitat Autónoma de Barcelona, Barcelona, Spain
| | - Mourad Mekaouche
- Aix-Marseille Université, CNRS, CRN2M-UMR7286, Marseille, France
| | - Isabel Illa
- Neuromuscular Diseases Unit, Hospital de la Santa Creu i Sant Pau, Universitat Autónoma de Barcelona, Barcelona, Spain
| | - Jérôme J Devaux
- Aix-Marseille Université, CNRS, CRN2M-UMR7286, Marseille, France
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45
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Miyata S, Taniguchi M, Koyama Y, Shimizu S, Tanaka T, Yasuno F, Yamamoto A, Iida H, Kudo T, Katayama T, Tohyama M. Association between chronic stress-induced structural abnormalities in Ranvier nodes and reduced oligodendrocyte activity in major depression. Sci Rep 2016; 6:23084. [PMID: 26976207 PMCID: PMC4791682 DOI: 10.1038/srep23084] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2015] [Accepted: 02/25/2016] [Indexed: 11/09/2022] Open
Abstract
Repeated stressful events are associated with the onset of major depressive disorder (MDD). We previously showed oligodendrocyte (OL)-specific activation of the serum/glucocorticoid-regulated kinase (SGK)1 cascade, increased expression of axon-myelin adhesion molecules, and elaboration of the oligodendrocytic arbor in the corpus callosum of chronically stressed mice. In the current study, we demonstrate that the nodes and paranodes of Ranvier in the corpus callosum were narrower in these mice. Chronic stress also led to diffuse redistribution of Caspr and Kv 1.1 and decreased the activity in white matter, suggesting a link between morphological changes in OLs and inhibition of axonal activity. OL primary cultures subjected to chronic stress resulted in SGK1 activation and translocation to the nucleus, where it inhibited the transcription of metabotropic glutamate receptors (mGluRs). Furthermore, the cAMP level and membrane potential of OLs were reduced by chronic stress exposure. We showed by diffusion tensor imaging that the corpus callosum of patients with MDD exhibited reduced fractional anisotropy, reflecting compromised white matter integrity possibly caused by axonal damage. Our findings suggest that chronic stress disrupts the organization of the nodes of Ranvier by suppressing mGluR activation in OLs, and that specific white matter abnormalities are closely associated with MDD onset.
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Affiliation(s)
- Shingo Miyata
- Division of Molecular Brain Science, Research Institute of Traditional Asian Medicine, Kinki University, Osaka-sayama, Osaka 589-8511, Japan
| | - Manabu Taniguchi
- Department of Anatomy and Neuroscience, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan
| | - Yoshihisa Koyama
- Department of Anatomy and Neuroscience, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan
| | - Shoko Shimizu
- Division of Molecular Brain Science, Research Institute of Traditional Asian Medicine, Kinki University, Osaka-sayama, Osaka 589-8511, Japan
| | - Takashi Tanaka
- Division of Molecular Brain Science, Research Institute of Traditional Asian Medicine, Kinki University, Osaka-sayama, Osaka 589-8511, Japan
| | - Fumihiko Yasuno
- Department of Psychiatry, Nara Medical University, Kashihara, Nara 634-8522, Japan
| | - Akihide Yamamoto
- Department of Investigative Radiology, National Cerebral and Cardiovascular Center, Suita, Osaka 565-8565, Japan
| | - Hidehiro Iida
- Department of Investigative Radiology, National Cerebral and Cardiovascular Center, Suita, Osaka 565-8565, Japan
| | - Takashi Kudo
- Department of Psychiatry, Osaka University Health Care Center, Toyonaka, Osaka 560-0043, Japan.,Department of Psychiatry, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan
| | - Taiichi Katayama
- Department of Child Development and Molecular Brain Science, United Graduate School of Child Development, Osaka University, Kanazawa University and Hamamatsu University School of Medicine, Suita, Osaka 565-0871, Japan
| | - Masaya Tohyama
- Division of Molecular Brain Science, Research Institute of Traditional Asian Medicine, Kinki University, Osaka-sayama, Osaka 589-8511, Japan.,Department of Child Development and Molecular Brain Science, United Graduate School of Child Development, Osaka University, Kanazawa University and Hamamatsu University School of Medicine, Suita, Osaka 565-0871, Japan.,Osaka Prefectural Hospital Organization, Osaka 558-8558, Japan
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46
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Susuki K, Otani Y, Rasband MN. Submembranous cytoskeletons stabilize nodes of Ranvier. Exp Neurol 2016; 283:446-51. [PMID: 26775177 DOI: 10.1016/j.expneurol.2015.11.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Revised: 11/10/2015] [Accepted: 11/23/2015] [Indexed: 01/22/2023]
Abstract
Rapid action potential propagation along myelinated axons requires voltage-gated Na(+) (Nav) channel clustering at nodes of Ranvier. At paranodes flanking nodes, myelinating glial cells interact with axons to form junctions. The regions next to the paranodes called juxtaparanodes are characterized by high concentrations of voltage-gated K(+) channels. Paranodal axoglial junctions function as barriers to restrict the position of these ion channels. These specialized domains along the myelinated nerve fiber are formed by multiple molecular mechanisms including interactions between extracellular matrix, cell adhesion molecules, and cytoskeletal scaffolds. This review highlights recent findings into the roles of submembranous cytoskeletal proteins in the stabilization of molecular complexes at and near nodes. Axonal ankyrin-spectrin complexes stabilize Nav channels at nodes. Axonal protein 4.1B-spectrin complexes contribute to paranode and juxtaparanode organization. Glial ankyrins enriched at paranodes facilitate node formation. Finally, disruption of spectrins or ankyrins by genetic mutations or proteolysis is involved in the pathophysiology of various neurological or psychiatric disorders.
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Affiliation(s)
- Keiichiro Susuki
- Department of Neuroscience, Cell Biology, and Physiology, Boonshoft School of Medicine, Wright State University, Dayton, OH, United States.
| | - Yoshinori Otani
- Department of Neuroscience, Cell Biology, and Physiology, Boonshoft School of Medicine, Wright State University, Dayton, OH, United States
| | - Matthew N Rasband
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, United States.
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47
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Lai HJ, Chiang YW, Yang CC, Hsieh ST, Chao CC, Lee MJ, Kuo CC. The Temporal Profiles of Changes in Nerve Excitability Indices in Familial Amyloid Polyneuropathy. PLoS One 2015; 10:e0141935. [PMID: 26529114 PMCID: PMC4631457 DOI: 10.1371/journal.pone.0141935] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Accepted: 10/14/2015] [Indexed: 01/19/2023] Open
Abstract
Familial amyloid polyneuropathy (FAP) caused by a mutation in transthyretin (TTR) gene is an autosomal dominant inherited disorder. The aim of this study is to explore the pathophysiological mechanism of FAP. We prospectively recruited 12 pauci-symptomatic carriers, 18 patients who harbor a TTR mutation, p.A97S, and two-age matched control groups. Data of nerve excitability test (NET) from ulnar motor and sensory axons were collected.NET study of ulnar motor axons of patients shows increased threshold and rheobase, reduced threshold elevation during hyperpolarizing threshold electrotonus (TE), and increased refractoriness. In sensory nerve studies, there are increased threshold reduction in depolarizing TE, lower slope of recovery and delayed time to overshoot after hyperpolarizing TE, increased refractoriness and superexcitability in recovery cycle. NET profiles obtained from the ulnar nerve of carriers show the increase of threshold and rheobase, whereas no significant threshold changes in hyperpolarizing TE and superexcitability. The regression models demonstrate that the increase of refractoriness and prolonged relative refractory period are correlated to the disease progression from carriers to patients. The marked increase of refractoriness at short-width stimulus suggests a defect in sodium current which may represent an early, pre-symptomatic pathophysiological change in TTR-FAP. Focal disruption of basal lamina and myelin may further increase the internodal capacity, manifested by the lower slope of recovery and delayed time to overshoot after hyperpolarization TE as well as the increase of superexcitability. NET could therefore make a pragmatic tool for monitoring disease progress from the very early stage of TTR-FAP.
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Affiliation(s)
- Hsing-Jung Lai
- Department of Neurology, National Taiwan University Hospital, Taipei, Taiwan
| | - Ya-Wen Chiang
- Department of Neurology, National Taiwan University Hospital, Taipei, Taiwan
| | - Chih-Chao Yang
- Department of Neurology, National Taiwan University Hospital, Taipei, Taiwan
| | - Sung-Tsang Hsieh
- Department of Neurology, National Taiwan University Hospital, Taipei, Taiwan
- Institute of Anatomy and Cell Biology, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Chi-Chao Chao
- Department of Neurology, National Taiwan University Hospital, Taipei, Taiwan
| | - Ming-Jen Lee
- Department of Neurology, National Taiwan University Hospital, Taipei, Taiwan
- Department of Medical Genetics, National Taiwan University Hospital, Taipei, Taiwan
| | - Chung-Chin Kuo
- Department of Neurology, National Taiwan University Hospital, Taipei, Taiwan
- Institute of Physiology, National Taiwan University College of Medicine, Taipei, Taiwan
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48
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Singh V, van Pelt ED, Stoop MP, Stingl C, Ketelslegers IA, Neuteboom RF, Catsman-Berrevoets CE, Luider TM, Hintzen RQ. Gray matter-related proteins are associated with childhood-onset multiple sclerosis. NEUROLOGY-NEUROIMMUNOLOGY & NEUROINFLAMMATION 2015; 2:e155. [PMID: 26445729 PMCID: PMC4582906 DOI: 10.1212/nxi.0000000000000155] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Accepted: 06/25/2015] [Indexed: 11/25/2022]
Abstract
Objective: To identify CSF biomarkers for multiple sclerosis (MS) in children with an initial acquired CNS demyelinating syndrome (ADS). Methods: CSF was collected from a cohort of 39 children with initial ADS, 18 of whom were diagnosed with MS and 21 of whom had a monophasic disease course. Proteomic analysis of trypsinized CSF (20 μL) was performed by nano-liquid chromatography Orbitrap mass spectrometry. Univariate statistical analysis was used to identify differentially abundant proteins between childhood-onset MS and monophasic ADS. Results: A total of 2,260 peptides corresponding to 318 proteins were identified in the total set of samples. Of these 2,260 peptides, 88 were identified as being most distinctive between MS and ADS. Fifty-three peptides, corresponding to 14 proteins, had higher abundance in children with MS compared to children with monophasic ADS. Twelve of these 14 proteins were linked to neuronal functions and structures, such as synapses, axons, and CNS proteases (e.g., neurofascin, carboxypeptidase E, brevican core protein, and contactin-2). The other 2 were functionally related to immune function. The 35 peptides identified with decreased abundance in children with MS corresponded to 7 proteins. Six of them were linked to innate immune function (e.g., haptoglobin, haptoglobin-related protein, C4b-binding protein alpha chain, and monocyte differentiation antigen CD14) and 1 was linked to cellular adhesion (protein diaphanous homolog 1). Conclusion: At first onset of ADS, CSF of children diagnosed with MS showed increased abundance of CNS gray matter–related proteins, whereas CSF of children with a monophasic disease course showed increased abundance of innate immunity–related proteins.
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Affiliation(s)
- Vaibhav Singh
- MS Centre ErasMS, Department of Neurology, Erasmus MC, Rotterdam, the Netherlands
| | - E Daniëlle van Pelt
- MS Centre ErasMS, Department of Neurology, Erasmus MC, Rotterdam, the Netherlands
| | - Marcel P Stoop
- MS Centre ErasMS, Department of Neurology, Erasmus MC, Rotterdam, the Netherlands
| | - Christoph Stingl
- MS Centre ErasMS, Department of Neurology, Erasmus MC, Rotterdam, the Netherlands
| | - Immy A Ketelslegers
- MS Centre ErasMS, Department of Neurology, Erasmus MC, Rotterdam, the Netherlands
| | - Rinze F Neuteboom
- MS Centre ErasMS, Department of Neurology, Erasmus MC, Rotterdam, the Netherlands
| | | | - Theo M Luider
- MS Centre ErasMS, Department of Neurology, Erasmus MC, Rotterdam, the Netherlands
| | - Rogier Q Hintzen
- MS Centre ErasMS, Department of Neurology, Erasmus MC, Rotterdam, the Netherlands
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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).
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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
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50
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Urbach H, Rauer S, Mader I, Paus S, Wagner J, Malter MP, Prüss H, Lewerenz J, Kassubek J, Hegen H, Auer M, Deisenhammer F, Ufer F, Bien CG, Baumgartner A. Supratentorial white matter blurring associated with voltage-gated potassium channel-complex limbic encephalitis. Neuroradiology 2015; 57:1203-9. [PMID: 26293130 DOI: 10.1007/s00234-015-1581-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 08/11/2015] [Indexed: 01/01/2023]
Abstract
INTRODUCTION Limbic encephalitis (LE) associated with voltage-gated potassium channel-complex antibodies (VGKC-LE) is frequently non-paraneoplastic and associated with marked improvement following corticosteroid therapy. Mesial temporal lobe abnormalities are present in around 80 % of patients. If associated or preceded by faciobrachial dystonic seizures, basal ganglia signal changes may occur. In some patients, blurring of the supratentorial white matter on T2-weighted images (SWMB) may be seen. The purpose of this study was to evaluate the incidence of SWMB and whether it is specific for VGKC-LE. METHODS Two experienced neuroradiologists independently evaluated signal abnormalities on FLAIR MRI in 79 patients with LE while unaware on the antibody type. RESULTS SWMB was independently assessed as present in 10 of 36 (28 %) compared to 2 (5 %) of 43 non-VGKC patients (p = 0.009). It was not related to the presence of LGI1 or CASPR2 proteins of VGKC antibodies. MRI showed increased temporomesial FLAIR signal in 22 (61 %) VGKC compared to 14 (33 %) non-VGKC patients (p = 0.013), and extratemporomesial structures were affected in one VGKC (3 %) compared to 11 (26 %) non-VGKC patients (p = 0.005). CONCLUSION SWMB is a newly described MRI sign rather specific for VGKC-LE.
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Affiliation(s)
- H Urbach
- Department of Neuroradiology, University Medical Center Freiburg, Breisacher Str. 64, 79106, Freiburg, Germany.
| | - S Rauer
- Department of Neurology, University Medical Center Freiburg, Freiburg, Germany
| | - I Mader
- Department of Neuroradiology, University Medical Center Freiburg, Breisacher Str. 64, 79106, Freiburg, Germany
| | - S Paus
- Department of Neurology, University Medical Center, Bonn, Germany
| | - J Wagner
- Department of Epileptology, University Medical Center, Bonn, Germany
| | - M P Malter
- Department of Neurology, University of Cologne, Cologne, Germany
| | - H Prüss
- Department of Neurology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - J Lewerenz
- Department of Neurology, Ulm University, Ulm, Germany
| | - J Kassubek
- Department of Neurology, Ulm University, Ulm, Germany
| | - H Hegen
- Department of Neurology, University Innsbruck, Innsbruck, Austria
| | - M Auer
- Department of Neurology, University Innsbruck, Innsbruck, Austria
| | - F Deisenhammer
- Department of Neurology, University Innsbruck, Innsbruck, Austria
| | - F Ufer
- Department of Neurology, University Medical Center, Hamburg, Germany
| | - C G Bien
- Epilepsy Centre Bethel, Bielefeld-Bethel, Germany
| | - A Baumgartner
- Department of Neurology, University Medical Center Freiburg, Freiburg, Germany
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