101
|
|
102
|
Roggenbuck JJ, Boucraut J, Delmont E, Conrad K, Roggenbuck D. Diagnostic insights into chronic-inflammatory demyelinating polyneuropathies. ANNALS OF TRANSLATIONAL MEDICINE 2018; 6:337. [PMID: 30306076 DOI: 10.21037/atm.2018.07.34] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Chronic inflammatory demyelinating polyneuropathy (CIDP) is a rare immune-mediated neuropathy with demyelination of nerve fibers as leading morphological feature. The course of disease can be chronic progressive or remitting relapsing. Whereas for acute immune-mediated neuropathies several serological markers have been identified and used successfully in clinical routine, the serological diagnosis of chronic variants such as CIDP has not yet been evolved satisfactory. The typical CIDP and its various atypical variants are characterized by a certain diversity of clinical phenotype and response to treatment. Thus, diagnostic markers could aid in the differential diagnosis of CIDP variants and stratification of patients for a better treatment response. Most patients respond well to a causal therapy including steroids, intravenous immunoglobulins and plasmapheresis. Apart from electrophysiological and morphological markers, several autoantibodies have been reported as candidate markers for CIDP, including antibodies against glycolipids or paranodal/nodal molecules. The present review provides a summary of the progress in autoantibody testing in CIDP and its possible implication on the stratification of the CIDP variants and treatment response.
Collapse
Affiliation(s)
| | - Joseph Boucraut
- Institut de Neurosciences de la Timone, Medicine Faculty, Aix Marseille University, Marseille, France.,Immunology laboratory, Conception Hospital, AP-HM, Marseille, France
| | - Emilien Delmont
- Referral Center for Neuromuscular Diseases and ALS, La Timone Hospital, AP-HM, Marseille, France
| | - Karsten Conrad
- Institute of Immunology, Technical University Dresden, Dresden, Germany
| | - Dirk Roggenbuck
- GA Generic Assays GmbH, Dahlewitz/Berlin, Germany.,Institute of Biotechnology, Faculty Environment and Natural Sciences, Brandenburg University of Technology, Senftenberg, Germany
| |
Collapse
|
103
|
Uncini A, Vallat JM. Autoimmune nodo-paranodopathies of peripheral nerve: the concept is gaining ground. J Neurol Neurosurg Psychiatry 2018; 89:627-635. [PMID: 29248893 DOI: 10.1136/jnnp-2017-317192] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Revised: 10/15/2017] [Accepted: 11/13/2017] [Indexed: 12/20/2022]
Abstract
Peripheral neuropathies are classified as primarily demyelinating or axonal. Microstructural alterations of the nodal region are the key to understand the pathophysiology of neuropathies with antibodies to gangliosides and the new category of nodo-paranodopathy has been proposed to better characterise these disorders and overcome some inadequacies of the dichotomous classification. Recently, the research in autoimmune neuropathies has been boosted by reports of patients carrying immunoglobulin G4 antibodies against paranodal axo-glial proteins with distinct phenotypes and showing loss of transverse bands, terminal myelin loop detachment, nodal widening and axonal loss. These patients have been classified up to now as chronic inflammatory demyelinating polyradiculoneuropathy but, in our opinion, better fit into the nodo-paranodopathy category because nerve injury is due to dismantling of the paranode, segmental de-remyelination is absent and the pathogenic mechanism is not inflammatory. Evidence from nerve conductions and electron microscopy studies in patients and mutant animal models can reconcile the apparent contrast between the electrophysiological 'demyelinating' features, explainable just by the paranodal involvement and the axonal pathology. These patients broaden the autoimmune nodo-paranodopathy category and re-emphasise the usage of the term that pointing to the site of nerve injury reminds specific pathophysiological mechanisms, reconciles contrasting electrophysiological and pathological findings, and avoids misdiagnosis and taxonomic confusion. In our opinion, the nodo-paranodopathy term more adequately classifies the peripheral nerve disorders due to an autoimmune attack directed and limited to the nodal region integrating the traditional classification of peripheral neuropathies.
Collapse
Affiliation(s)
- Antonino Uncini
- Department of Neurosciences, Imaging and Clinical Sciences University G. d'Annunzio, Chieti-Pescara, Italy
| | - Jean-Michel Vallat
- Department of Neurology and 'Centre de Référence des neuropathies rares', CHU Limoges, Limoges, France
| |
Collapse
|
104
|
Vural A, Doppler K, Meinl E. Autoantibodies Against the Node of Ranvier in Seropositive Chronic Inflammatory Demyelinating Polyneuropathy: Diagnostic, Pathogenic, and Therapeutic Relevance. Front Immunol 2018; 9:1029. [PMID: 29867996 PMCID: PMC5960694 DOI: 10.3389/fimmu.2018.01029] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 04/24/2018] [Indexed: 11/13/2022] Open
Abstract
Discovery of disease-associated autoantibodies has transformed the clinical management of a variety of neurological disorders. Detection of autoantibodies aids diagnosis and allows patient stratification resulting in treatment optimization. In the last years, a set of autoantibodies against proteins located at the node of Ranvier has been identified in patients with chronic inflammatory demyelinating polyneuropathy (CIDP). These antibodies target neurofascin, contactin1, or contactin-associated protein 1, and we propose to name CIDP patients with these antibodies collectively as seropositive. They have unique clinical characteristics that differ from seronegative CIDP. Moreover, there is compelling evidence that autoantibodies are relevant for the pathogenesis. In this article, we review the current knowledge on the characteristics of autoantibodies against the node of Ranvier proteins and their clinical relevance in CIDP. We start with a description of the structure of the node of Ranvier followed by a summary of assays used to identify seropositive patients; and then, we describe clinical features and characteristics linked to seropositivity. We review knowledge on the role of these autoantibodies for the pathogenesis with relevance for the emerging concept of nodopathy/paranodopathy and summarize the treatment implications.
Collapse
Affiliation(s)
- Atay Vural
- Institute of Clinical Neuroimmunology, Biomedical Center, University Hospitals, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany.,Research Center for Translational Medicine, Koç University, Istanbul, Turkey
| | - Kathrin Doppler
- Department of Neurology, University Hospital Würzburg, Würzburg, Germany
| | - Edgar Meinl
- Institute of Clinical Neuroimmunology, Biomedical Center, University Hospitals, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
| |
Collapse
|
105
|
Härtig F, Ross M, Dammeier NM, Fedtke N, Heiling B, Axer H, Décard BF, Auffenberg E, Koch M, Rattay TW, Krumbholz M, Bornemann A, Lerche H, Winter N, Grimm A. Nerve Ultrasound Predicts Treatment Response in Chronic Inflammatory Demyelinating Polyradiculoneuropathy-a Prospective Follow-Up. Neurotherapeutics 2018; 15:439-451. [PMID: 29435815 PMCID: PMC5935640 DOI: 10.1007/s13311-018-0609-4] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
As reliable biomarkers of disease activity are lacking, monitoring of therapeutic response in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) remains a challenge. We sought to determine whether nerve ultrasound and electrophysiology scoring could close this gap. In CIDP patients (fulfilling EFNS/PNS criteria), we performed high-resolution nerve ultrasound to determine ultrasound pattern sum scores (UPSS) and predominant echotexture nerve conduction study scores (NCSS) as well as Medical Research Council sum scores (MRCSS) and inflammatory neuropathy cause and treatment disability scores (INCAT) at baseline and after 12 months of standard treatment. We retrospectively correlated ultrasound morphology with nerve histology when available. 72/80 CIDP patients featured multifocal nerve enlargement, and 35/80 were therapy-naïve. At baseline, clinical scores correlated with NCSS (r2 = 0.397 and r2 = 0.443, p < 0.01), but not or hardly with UPSS (Medical Research Council sum scores MRCSS r2 = 0.013, p = 0.332; inflammatory neuropathy cause and treatment disability scores INCAT r2 = 0.053, p = 0.048). Longitudinal changes in clinical scores, however, correlated significantly with changes in both UPSS and NCSS (r2 = 0.272-0.414, p < 0.0001). Combining nerve/fascicle size with echointensity and histology at baseline, we noted 3 distinct classes: 1) hypoechoic enlargement, reflecting active inflammation and onion bulbs; 2) nerve enlargement with additional hyperechogenic fascicles/perifascicular tissue in > 50% of measured segments, possibly reflecting axonal degeneration; and 3) almost no enlargement, reflecting "burned-out" or "cured" disease without active inflammation. Clinical improvement after 12 months was best in patients with pattern 1 (up to 75% vs up to 43% in pattern 2/3, Fisher's exact test p < 0.05). Nerve ultrasound has additional value not only for diagnosis, but also for classification of disease state and may predict treatment response.
Collapse
Affiliation(s)
- Florian Härtig
- Department of Neurology, Tübingen University Hospital, University of Tübingen, Hoppe-Seyler-Str. 3, 72076, Tubingen, Germany
- Hertie-Institute for Clinical Brain Research, University of Tübingen, 72076, Tubingen, Germany
| | - Marlene Ross
- Department of Neurology, Tübingen University Hospital, University of Tübingen, Hoppe-Seyler-Str. 3, 72076, Tubingen, Germany
| | - Nele Maria Dammeier
- Department of Neurology, Tübingen University Hospital, University of Tübingen, Hoppe-Seyler-Str. 3, 72076, Tubingen, Germany
- Hertie-Institute for Clinical Brain Research, University of Tübingen, 72076, Tubingen, Germany
| | - Nadin Fedtke
- Hans Berger Department of Neurology, Jena University Hospital, Jena, 07747, Germany
| | - Bianka Heiling
- Hans Berger Department of Neurology, Jena University Hospital, Jena, 07747, Germany
| | - Hubertus Axer
- Hans Berger Department of Neurology, Jena University Hospital, Jena, 07747, Germany
| | - Bernhard F Décard
- Department of Neurology, Basel University Hospital, Basel, 4031, Switzerland
| | - Eva Auffenberg
- Department of Neurology, Tübingen University Hospital, University of Tübingen, Hoppe-Seyler-Str. 3, 72076, Tubingen, Germany
- Hertie-Institute for Clinical Brain Research, University of Tübingen, 72076, Tubingen, Germany
| | - Marilin Koch
- Department of Neurology, Tübingen University Hospital, University of Tübingen, Hoppe-Seyler-Str. 3, 72076, Tubingen, Germany
- Hertie-Institute for Clinical Brain Research, University of Tübingen, 72076, Tubingen, Germany
| | - Tim W Rattay
- Department of Neurology, Tübingen University Hospital, University of Tübingen, Hoppe-Seyler-Str. 3, 72076, Tubingen, Germany
- Hertie-Institute for Clinical Brain Research, University of Tübingen, 72076, Tubingen, Germany
| | - Markus Krumbholz
- Department of Neurology, Tübingen University Hospital, University of Tübingen, Hoppe-Seyler-Str. 3, 72076, Tubingen, Germany
- Hertie-Institute for Clinical Brain Research, University of Tübingen, 72076, Tubingen, Germany
| | - Antje Bornemann
- Institute of Brain Research, University of Tübingen, 72076, Tubingen, Germany
| | - Holger Lerche
- Department of Neurology, Tübingen University Hospital, University of Tübingen, Hoppe-Seyler-Str. 3, 72076, Tubingen, Germany
- Hertie-Institute for Clinical Brain Research, University of Tübingen, 72076, Tubingen, Germany
| | - Natalie Winter
- Department of Neurology, Tübingen University Hospital, University of Tübingen, Hoppe-Seyler-Str. 3, 72076, Tubingen, Germany
- Hertie-Institute for Clinical Brain Research, University of Tübingen, 72076, Tubingen, Germany
| | - Alexander Grimm
- Department of Neurology, Tübingen University Hospital, University of Tübingen, Hoppe-Seyler-Str. 3, 72076, Tubingen, Germany.
- Hertie-Institute for Clinical Brain Research, University of Tübingen, 72076, Tubingen, Germany.
| |
Collapse
|
106
|
|
107
|
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.
Collapse
Affiliation(s)
- Inga Koneczny
- Institute of Neurology, Medical University of Vienna, Vienna, Austria
| |
Collapse
|
108
|
Sommer C, Geber C, Young P, Forst R, Birklein F, Schoser B. Polyneuropathies. DEUTSCHES ÄRZTEBLATT INTERNATIONAL 2018. [DOI: 10.3238/arztebl.2018.0083] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
|
109
|
Huijbers MG, Plomp JJ, van der Maarel SM, Verschuuren JJ. IgG4-mediated autoimmune diseases: a niche of antibody-mediated disorders. Ann N Y Acad Sci 2018; 1413:92-103. [PMID: 29377160 DOI: 10.1111/nyas.13561] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 10/19/2017] [Accepted: 10/30/2017] [Indexed: 12/11/2022]
Abstract
Immunoglobulin 4 (IgG4) is one of four human IgG subclasses and has several unique functional characteristics. It exhibits low affinity for complement and for most Fc receptors. It furthermore has generally high affinity for its antigen, with binding occurring in a monovalent fashion, as IgG4 can exchange Fab-arms with other IgG4 molecules. Because of these characteristics, IgG4 is believed to block its targets and prevent inflammation, which, depending on the setting, can have a protective or pathogenic effect. One example of IgG4 pathogenicity is muscle-specific kinase (MuSK) myasthenia gravis (MG), in which patients develop IgG4 MuSK autoantibodies, resulting in muscle weakness. As a consequence of the distinct IgG4 characteristics, the pathomechanism of MuSK MG is very different from IgG1-and IgG3-mediated autoimmune diseases, such as acetylcholine receptor MG. In recent years, new autoantibodies in a spectrum of autoimmune diseases have been discovered. Interestingly, some were found to be predominantly IgG4. These IgG4-mediated autoimmune diseases share many pathomechanistic aspects with MuSK MG, suggesting that IgG4-mediated autoimmunity forms a separate niche among the antibody-mediated disorders. In this review, we summarize the group of IgG4-mediated autoimmune diseases, discuss the role of IgG4 in MuSK MG, and highlight interesting future research questions for IgG4-mediated autoimmunity.
Collapse
Affiliation(s)
- Maartje G Huijbers
- Departments of Neurology, Leiden University Medical Centre, Leiden, the Netherlands.,Department of Human Genetics, Leiden University Medical Centre, Leiden, the Netherlands
| | - Jaap J Plomp
- Departments of Neurology, Leiden University Medical Centre, Leiden, the Netherlands
| | | | - Jan J Verschuuren
- Departments of Neurology, Leiden University Medical Centre, Leiden, the Netherlands
| |
Collapse
|
110
|
Décard BF, Pham M, Grimm A. Ultrasound and MRI of nerves for monitoring disease activity and treatment effects in chronic dysimmune neuropathies – Current concepts and future directions. Clin Neurophysiol 2018; 129:155-167. [DOI: 10.1016/j.clinph.2017.10.028] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2017] [Revised: 10/03/2017] [Accepted: 10/07/2017] [Indexed: 02/07/2023]
|
111
|
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: 42] [Impact Index Per Article: 7.0] [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.
Collapse
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
| |
Collapse
|
112
|
Fujita A, Ogata H, Yamasaki R, Matsushita T, Kira JI. Parallel fluctuation of anti-neurofascin 155 antibody levels with clinico-electrophysiological findings in patients with chronic inflammatory demyelinating polyradiculoneuropathy. J Neurol Sci 2017; 384:107-112. [PMID: 29249367 DOI: 10.1016/j.jns.2017.11.035] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 11/07/2017] [Accepted: 11/26/2017] [Indexed: 01/28/2023]
Abstract
BACKGROUND The long-term clinical course and closely related biomarkers in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) with anti-neurofascin 155 (NF155) antibodies remain to be elucidated. METHODS We retrospectively studied the longitudinal clinical courses of three Japanese male anti-NF155 antibody-positive CIDP patients. Anti-NF155 antibody levels were measured by flow cytometry using HEK293 cell lines stably expressing human NF155. RESULTS All three patients presented with chronic progressive sensorimotor disturbance, with ages at onset of 16, 26, and 34years old, and they were followed for 58, 31, and 38months, respectively, from the onset. All patients had postural tremor and generalized decreased deep tendon reflexes. Peak cerebrospinal fluid protein levels were >400mg/dl, and nerve conduction studies (NCS) showed severe demyelination patterns. Combined immunotherapies including intravenous immunoglobulin, plasma exchange, corticosteroids, and other immunosuppressants ameliorated clinical severity and NCS abnormalities, with improvements of >10kg in grip strength and at least 20% in F-wave latencies. However, their symptoms exacerbated after the immunotherapies were tapered. Anti-NF155 antibody levels varied in parallel with the clinical and electrophysiological changes, or preceded them. CONCLUSION The patients' clinical courses suggest that anti-NF155 antibody levels and NCS findings could be disease activity markers in anti-NF155 antibody-positive CIDP.
Collapse
Affiliation(s)
- Atsushi Fujita
- Department of Neurology, Neurological Institute, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Hidenori Ogata
- Department of Neurology, Neurological Institute, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Ryo Yamasaki
- Department of Neurology, Neurological Institute, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Takuya Matsushita
- Department of Neurology, Neurological Institute, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Jun-Ichi Kira
- Department of Neurology, Neurological Institute, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
| |
Collapse
|
113
|
Martinez-Martinez L, Lleixà MC, Boera-Carnicero G, Cortese A, Devaux J, Siles A, Rajabally Y, Martinez-Piñeiro A, Carvajal A, Pardo J, Delmont E, Attarian S, Diaz-Manera J, Callegari I, Marchioni E, Franciotta D, Benedetti L, Lauria G, de la Calle Martin O, Juárez C, Illa I, Querol L. Anti-NF155 chronic inflammatory demyelinating polyradiculoneuropathy strongly associates to HLA-DRB15. J Neuroinflammation 2017; 14:224. [PMID: 29145880 PMCID: PMC5691853 DOI: 10.1186/s12974-017-0996-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2017] [Accepted: 11/06/2017] [Indexed: 12/02/2022] Open
Abstract
Background The aim of the research is to study the human leukocyte antigen (HLA) class II allele frequencies in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) associated with anti-neurofascin 155 (NF155) antibodies. Methods Thirteen anti-NF155+ and 35 anti-NF155 negative (anti-NF155neg) CIDP patients were included in a case-control study. The frequencies of the DRB1 HLA allele were analyzed in all patients while DQ frequencies were only studied in patients sharing the DRB1*15 allele. In silico HLA-peptide binding and NF155 antigenicity, predictions were performed to analyze overlap between presented peptides and antigenic regions. Results DRB1*15 alleles (DRB1*15:01 and DRB1*15:02) were present in 10 out of 13 anti-NF155+ CIDP patients and in only 5 out of 35 anti-NF155neg CIDP patients (77 vs 14%; OR = 20, CI = 4.035 to 99.13). DRB1*15 alleles appeared also in significantly higher proportions in anti-NF155+ CIDP than in normal population (77 vs 17%; OR = 16.9, CI = 4.434 to 57.30). Seven anti-NF155+ CIDP patients (53%) and 5 anti-NF155neg CIDP patients had the DRB1*15:01 allele (OR = 7, p = 0.009), while 3 anti-NF155+ CIDP patients and none of the anti-NF155neg CIDP patients had the DRB1*15:02 allele (OR = 23.6, p = 0.016). In silico analysis of the NF155 peptides binding to DRB1*15 alleles showed significant overlap in the peptides presented by the 15:01 and 15:02 alleles, suggesting functional homology. Conclusions DRB1*15 alleles are the first strong risk factor associated to a CIDP subset, providing additional evidence that anti-NF155+ CIDP patients constitute a differentiated disease within the CIDP syndrome. Electronic supplementary material The online version of this article (10.1186/s12974-017-0996-1) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Laura Martinez-Martinez
- Immunology Department, Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Ma Cinta Lleixà
- Neuromuscular Diseases Unit, Department of Neurology, Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Mas Casanovas 90, 08041, Barcelona, Spain.,Centro para la Investigación Biomédica en Red en Enfermedades Raras, CIBERER, Madrid, Spain
| | - Gemma Boera-Carnicero
- Immunology Department, Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Andrea Cortese
- IRCCS Foundation C. Mondino National Neurological Institute, Pavia, Italy.,MRC Centre for Neuromuscular Diseases, National Hospital for Neurology and Neurosurgery, UCL Institute of Neurology, Queen Square, London, UK
| | - Jérôme Devaux
- Centre de Recherche en Neurobiologie et Neurophysiologie de Marseille - CRN2M, UMR 7286, CNRS, Aix-Marseille Université, Marseille, France
| | - Ana Siles
- Neuromuscular Diseases Unit, Department of Neurology, Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Mas Casanovas 90, 08041, Barcelona, Spain.,Centro para la Investigación Biomédica en Red en Enfermedades Raras, CIBERER, Madrid, Spain
| | - Yusuf Rajabally
- Regional Neuromuscular Clinic, Queen Elizabeth Hospital, University Hospitals of Birmingham, Birmingham, UK
| | - Alicia Martinez-Piñeiro
- Neurology Department, Hospital Germans Trias i Pujol, Universitat Autònoma de Barcelona, Badalona, Spain
| | | | - Julio Pardo
- Department of Neurology, Hospital Clínico de Santiago, Santiago de Compostela, Spain
| | - Emilien Delmont
- Centre de Recherche en Neurobiologie et Neurophysiologie de Marseille - CRN2M, UMR 7286, CNRS, Aix-Marseille Université, Marseille, France.,Referral Center for ALS and Neuromuscular Diseases, Timone University Hospital, Aix-Marseille University, Marseille, France
| | - Shahram Attarian
- Referral Center for ALS and Neuromuscular Diseases, Timone University Hospital, Aix-Marseille University, Marseille, France
| | - Jordi Diaz-Manera
- Neuromuscular Diseases Unit, Department of Neurology, Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Mas Casanovas 90, 08041, Barcelona, Spain.,Centro para la Investigación Biomédica en Red en Enfermedades Raras, CIBERER, Madrid, Spain
| | - Ilaria Callegari
- IRCCS Foundation C. Mondino National Neurological Institute, Pavia, Italy.,Neuroscience Consortium, Monza Policlinico and Pavia Mondino, University of Pavia, Pavia, Italy
| | - Enrico Marchioni
- IRCCS Foundation C. Mondino National Neurological Institute, Pavia, Italy
| | - Diego Franciotta
- IRCCS Foundation C. Mondino National Neurological Institute, Pavia, Italy
| | - Luana Benedetti
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genova and IRCCS AOU San Martino-IST, Genoa, Italy
| | - Guiseppe Lauria
- Neuroalgology Unit, IRCCS Foundation "Carlo Besta" Neurological Institute, Milan, Italy.,Department of Biomedical and Clinical Sciences "Luigi Sacco", University of Milan, Milan, Italy
| | - Oscar de la Calle Martin
- Immunology Department, Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Cándido Juárez
- Immunology Department, Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Isabel Illa
- Neuromuscular Diseases Unit, Department of Neurology, Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Mas Casanovas 90, 08041, Barcelona, Spain.,Centro para la Investigación Biomédica en Red en Enfermedades Raras, CIBERER, Madrid, Spain
| | - Luis Querol
- Neuromuscular Diseases Unit, Department of Neurology, Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Mas Casanovas 90, 08041, Barcelona, Spain. .,Centro para la Investigación Biomédica en Red en Enfermedades Raras, CIBERER, Madrid, Spain.
| |
Collapse
|
114
|
Illa I. ARTHUR ASBURY LECTURE: Chronic inflammatory demyelinating polyradiculoneuropathy: clinical aspects and new animal models of auto-immunity to nodal components. J Peripher Nerv Syst 2017; 22:418-424. [DOI: 10.1111/jns.12237] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 10/20/2017] [Accepted: 10/20/2017] [Indexed: 12/28/2022]
Affiliation(s)
- Isabel Illa
- Unitat Neuromuscular Servei Neurología; Hospital Santa Creu i Sant Pau, Universitat Autònoma Barcelona, CIBERER; Barcelona Spain
| |
Collapse
|
115
|
Antibodies against peripheral nerve antigens in chronic inflammatory demyelinating polyradiculoneuropathy. Sci Rep 2017; 7:14411. [PMID: 29089585 PMCID: PMC5663697 DOI: 10.1038/s41598-017-14853-4] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Accepted: 10/17/2017] [Indexed: 01/01/2023] Open
Abstract
Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a heterogeneous disease in which diverse autoantibodies have been described but systematic screening has never been performed. Detection of CIDP-specific antibodies may be clinically useful. We developed a screening protocol to uncover novel reactivities in CIDP. Sixty-five CIDP patients and 28 controls were included in our study. Three patients (4.6%) had antibodies against neurofascin 155, four (6.2%) against contactin-1 and one (1.5%) against the contactin-1/contactin-associated protein-1 complex. Eleven (18.6%) patients showed anti-ganglioside antibodies, and one (1.6%) antibodies against peripheral myelin protein 2. No antibodies against myelin protein zero, contactin-2/contactin-associated protein-2 complex, neuronal cell adhesion molecule, gliomedin or the voltage-gated sodium channel were detected. In IgG experiments, three patients (5.3%) showed a weak reactivity against motor neurons; 14 (24.6%) reacted against DRG neurons, four of them strongly (7.0%), and seven (12.3%) reacted against Schwann cells, three of them strongly (5.3%). In IgM experiments, six patients (10.7%) reacted against DRG neurons, while three (5.4%) reacted against Schwann cells. However, results were not statistically significant when compared to controls. Immunoprecipitation experiments identified CD9 and L1CAM as potential antigens, but reactivity could not be confirmed with cell-based assays. In summary, we describe a diverse autoantibody repertoire in CIDP patients, reinforcing the hypothesis of CIDP’s pathophysiological heterogeneity.
Collapse
|
116
|
Delmont E, Manso C, Querol L, Cortese A, Berardinelli A, Lozza A, Belghazi M, Malissart P, Labauge P, Taieb G, Yuki N, Illa I, Attarian S, Devaux JJ. Autoantibodies to nodal isoforms of neurofascin in chronic inflammatory demyelinating polyneuropathy. Brain 2017; 140:1851-1858. [PMID: 28575198 DOI: 10.1093/brain/awx124] [Citation(s) in RCA: 147] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 04/12/2017] [Indexed: 12/11/2022] Open
Abstract
Chronic inflammatory demyelination polyneuropathy is a heterogeneous and treatable immune-mediated disorder that lacks biomarkers to support diagnosis. Recent evidence indicates that paranodal proteins (contactin 1, contactin-associated protein 1, and neurofascin-155) are the targets of autoantibodies in subsets of patients showing distinct clinical presentations. Here, we identified neurofascin-186 and neurofascin-140 as the main targets of autoantibodies in five patients presenting IgG reactivity against the nodes of Ranvier. Four patients displayed predominantly IgG4 antibodies, and one patient presented IgG3 antibodies that activated the complement pathway in vitro. These patients present distinct clinical features compared to those with anti-neurofascin-155 IgG4. Most patients had a severe phenotype associated with conduction block or decreased distal motor amplitude. Four patients had a subacute-onset and sensory ataxia. Two patients presented with nephrotic syndromes and one patient with an IgG4-related retroperitoneal fibrosis. Intravenous immunoglobulin and corticosteroids were effective in three patients, and one patient remitted following rituximab treatment. Clinical remission was associated with autoantibody depletion and with recovery of conduction block and distal motor amplitude suggesting a nodo-paranodopathy. Our data demonstrate that the pathogenic mechanisms responsible for chronic inflammatory demyelination polyneuropathy are broad and may include dysfunctions at the nodes of Ranvier in a subgroup of patients.
Collapse
Affiliation(s)
- Emilien Delmont
- Referral Center for ALS and Neuromuscular Diseases, Timone University Hospital, Aix-Marseille University, France.,Aix-Marseille Université, CNRS, CRN2M-UMR7286, Marseille, France
| | - 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
| | - Andrea Cortese
- IRCCS, C. Mondino National Neurological Institute, Pavia, Italy.,MRC Centre for Neuromuscular Diseases, National Hospital for Neurology and Neurosurgery, UCL Institute of Neurology, Queen Square, London, United Kingdom
| | | | | | - Maya Belghazi
- Referral Center for ALS and Neuromuscular Diseases, Timone University Hospital, Aix-Marseille University, France
| | - Pauline Malissart
- Department of Neurology, Gui de Chauliac Hospital, Montpellier University Hospital Center, Montpellier, France
| | - Pierre Labauge
- Department of Neurology, Gui de Chauliac Hospital, Montpellier University Hospital Center, Montpellier, France
| | - Guillaume Taieb
- Department of Neurology, Gui de Chauliac Hospital, Montpellier University Hospital Center, Montpellier, France
| | - Nobuhiro Yuki
- Department of Neurology, Mishima Hospital, Niigata, Japan
| | - Isabel Illa
- Neuromuscular Diseases Unit, Hospital de la Santa Creu i Sant Pau, Universitat Autónoma de Barcelona, Barcelona, Spain
| | - Shahram Attarian
- Referral Center for ALS and Neuromuscular Diseases, Timone University Hospital, Aix-Marseille University, France
| | - Jérôme J Devaux
- Aix-Marseille Université, CNRS, CRN2M-UMR7286, Marseille, France
| |
Collapse
|
117
|
Autoantibodies in chronic inflammatory neuropathies: diagnostic and therapeutic implications. Nat Rev Neurol 2017; 13:533-547. [PMID: 28708133 DOI: 10.1038/nrneurol.2017.84] [Citation(s) in RCA: 139] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The chronic inflammatory neuropathies (CINs) are rare, very disabling autoimmune disorders that generally respond well to immune therapies such as intravenous immunoglobulin (IVIg). The most common forms of CIN are chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), multifocal motor neuropathy, and polyneuropathy associated with monoclonal gammopathy of unknown significance. The field of CIN has undergone a major advance with the identification of IgG4 autoantibodies directed against paranodal proteins in patients with CIDP. Although these autoantibodies are only found in a small subset of patients with CIDP, they can be used to guide therapeutic decision-making, as these patients have a poor response to IVIg. These observations provide proof of concept that identifying the target antigens in tissue-specific antibody-mediated autoimmune diseases is important, not only to understand their underlying pathogenic mechanisms, but also to correctly diagnose and treat affected patients. This state-of-the-art Review focuses on the role of autoantibodies against nodes of Ranvier in CIDP, a clinically relevant emerging field of research. The role of autoantibodies in other immune-mediated neuropathies, including other forms of CIN, primary autoimmune neuropathies, neoplasms, and systemic diseases that resemble CIN, are also discussed.
Collapse
|
118
|
Autoantibody responses to nodal and paranodal antigens in chronic inflammatory neuropathies. J Neuroimmunol 2017; 309:41-46. [PMID: 28601286 DOI: 10.1016/j.jneuroim.2017.05.002] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 05/09/2017] [Accepted: 05/10/2017] [Indexed: 12/11/2022]
Abstract
Autoantibodies to nodal/paranodal proteins have been reported in patients with chronic inflammatory demyelinating polyneuropathy (CIDP) and multifocal motor neuropathy (MMN). To determine the frequency of anti-paranodal antibodies in our cohort of CIDP patients and to validate the presence anti-nodal antibodies in MMN, sera were screened for IgG against human neurofascin 155, contactin-1, neurofascin 186 and gliomedin using ELISA. In CIDP patients, 7% were anti-NF155 IgG4 positive and 7% were anti-CNTN1 IgG4 positive. Positive results were confirmed using cell based assays and indirect immunofluorescence on teased nerve fibres. We did not detect IgG autoantibodies against these nodal/paranodal antigens in MMN patients.
Collapse
|
119
|
Gonsalvez DG, Tran G, Fletcher JL, Hughes RA, Hodgkinson S, Wood RJ, Yoo SW, De Silva M, Agnes WW, McLean C, Kennedy P, Kilpatrick TJ, Murray SS, Xiao J. A Brain-Derived Neurotrophic Factor-Based p75 NTR Peptide Mimetic Ameliorates Experimental Autoimmune Neuritis Induced Axonal Pathology and Demyelination. eNeuro 2017; 4:ENEURO.0142-17.2017. [PMID: 28680965 PMCID: PMC5496185 DOI: 10.1523/eneuro.0142-17.2017] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 06/15/2017] [Accepted: 06/19/2017] [Indexed: 01/09/2023] Open
Abstract
Axonal damage and demyelination are major determinants of disability in patients with peripheral demyelinating neuropathies. The neurotrophin family of growth factors are essential for the normal development and myelination of the peripheral nervous system (PNS), and as such are potential therapeutic candidates for ameliorating axonal and myelin damage. In particular, BDNF promotes peripheral nerve myelination via p75 neurotrophin receptor (p75NTR) receptors. Here, we investigated the therapeutic efficacy of a small structural mimetic of the region of BDNF that binds to p75NTR (cyclo-dPAKKR) in experimental autoimmune neuritis (EAN), an established animal model of peripheral demyelinating neuropathy. Examination of rodents induced with EAN revealed that p75NTR is abundantly expressed in affected peripheral nerves. We found that systemic administration of cyclo-dPAKKR ameliorates EAN disease severity and accelerates recovery. Animals treated with cyclo-dPAKKR displayed significantly better motor performance compared to control animals. Histological assessment revealed that cyclo-dPAKKR administration limits the extent of inflammatory demyelination and axonal damage, and protects against the disruption of nodal architecture in affected peripheral nerves. In contrast, a structural control peptide of cyclo-dPAKKR exerted no influence. Moreover, all the beneficial effects of cyclo-dPAKKR in EAN are abrogated in p75NTR heterozygous mice, strongly suggesting a p75NTR-dependent effect. Taken together, our data demonstrate that cyclo-dPAKKR ameliorates functional and pathological defects of EAN in a p75NTR-dependant manner, suggesting that p75NTR is a therapeutic target to consider for future treatment of peripheral demyelinating diseases and targeting of p75NTR is a strategy worthy of further investigation.
Collapse
MESH Headings
- Amyloid beta-Protein Precursor/metabolism
- Animals
- Axons/drug effects
- Axons/pathology
- Axons/ultrastructure
- Demyelinating Diseases/drug therapy
- Demyelinating Diseases/etiology
- Disease Models, Animal
- Dose-Response Relationship, Drug
- Female
- Gene Expression Regulation/drug effects
- Gene Expression Regulation/genetics
- Mice
- Mice, Inbred C57BL
- Microscopy, Confocal
- Microscopy, Electron, Transmission
- Myelin Basic Protein/metabolism
- Neuritis, Autoimmune, Experimental/complications
- Neuritis, Autoimmune, Experimental/genetics
- Neuritis, Autoimmune, Experimental/pathology
- Oligopeptides/therapeutic use
- RNA, Messenger/metabolism
- Rats
- Rats, Inbred Lew
- Receptors, Nerve Growth Factor/chemistry
- Receptors, Nerve Growth Factor/genetics
- Receptors, Nerve Growth Factor/metabolism
- Receptors, Nerve Growth Factor/therapeutic use
- Statistics, Nonparametric
Collapse
Affiliation(s)
- David G. Gonsalvez
- Department of Anatomy and Neuroscience, The University of Melbourne, VIC 3010, Australia
| | - Giang Tran
- Liverpool Hospital, The University of New South Wales, NSW 2170, Australia
| | - Jessica L. Fletcher
- Department of Anatomy and Neuroscience, The University of Melbourne, VIC 3010, Australia
| | - Richard A. Hughes
- Department of Pharmacology and Therapeutics, The University of Melbourne, VIC 3010, Australia
| | - Suzanne Hodgkinson
- Liverpool Hospital, The University of New South Wales, NSW 2170, Australia
| | - Rhiannon J. Wood
- Department of Anatomy and Neuroscience, The University of Melbourne, VIC 3010, Australia
| | - Sang Won Yoo
- Department of Anatomy and Neuroscience, The University of Melbourne, VIC 3010, Australia
| | - Mithraka De Silva
- Department of Anatomy and Neuroscience, The University of Melbourne, VIC 3010, Australia
| | - Wong W. Agnes
- Department of Anatomy and Neuroscience, The University of Melbourne, VIC 3010, Australia
| | - Catriona McLean
- Victorian Neuromuscular Laboratory Services, Alfred Health, VIC 3004, Australia
| | - Paul Kennedy
- Victorian Neuromuscular Laboratory Services, Alfred Health, VIC 3004, Australia
| | - Trevor J. Kilpatrick
- Department of Anatomy and Neuroscience, The University of Melbourne, VIC 3010, Australia
| | - Simon S. Murray
- Department of Anatomy and Neuroscience, The University of Melbourne, VIC 3010, Australia
| | - Junhua Xiao
- Department of Anatomy and Neuroscience, The University of Melbourne, VIC 3010, Australia
| |
Collapse
|
120
|
Saifetiarova J, Liu X, Taylor AM, Li J, Bhat MA. Axonal domain disorganization in Caspr1 and Caspr2 mutant myelinated axons affects neuromuscular junction integrity, leading to muscle atrophy. J Neurosci Res 2017; 95:1373-1390. [PMID: 28370195 DOI: 10.1002/jnr.24052] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 02/14/2017] [Accepted: 02/24/2017] [Indexed: 12/19/2022]
Abstract
Bidirectional interactions between neurons and myelinating glial cells result in formation of axonal domains along myelinated fibers. Loss of axonal domains leads to detrimental consequences on nerve structure and function, resulting in reduced conductive properties and the diminished ability to reliably transmit signals to the targets they innervate. Thus, impairment of peripheral myelinated axons that project to the surface of muscle fibers and form neuromuscular junction (NMJ) synapses leads to muscle dysfunction. The goal of our studies was to determine how altered electrophysiological properties due to axonal domain disorganization lead to muscle pathology, which is relevant to a variety of peripheral neuropathies, demyelinating diseases, and neurodegenerative disorders. Using conventional Contactin-Associated Protein 1 (Caspr1) and Caspr2 single or double mutants with disrupted paranodal, juxtaparanodal, or both regions, respectively, in peripheral myelinated axons, we correlated defects in NMJ integrity and muscle pathology. Our data show that loss of axonal domains in Caspr1 and Caspr2 single and double mutants primarily alters distal myelinated fibers together with presynaptic terminals, eventually leading to NMJ denervation and reduction in postsynaptic endplate areas. Moreover, reduction in conductive properties of peripheral myelinated fibers together with NMJ disintegration leads to muscle atrophy in Caspr1 mutants or muscle fiber degeneration accompanied by mitochondrial dysfunction in Caspr1/Caspr2 double mutants. Together, our data indicate that proper organization of axonal domains in myelinated fibers is critical for optimal propagation of electrical signals, NMJ integrity, and muscle health, and provide insights into a wide range of pathologies that result in reduced nerve conduction leading to muscle atrophy. © 2017 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Julia Saifetiarova
- Department of Cellular and Integrative Physiology, Center for Biomedical Neuroscience, School of Medicine, University of Texas Health Science Center, San Antonio, Texas
| | - Xi Liu
- Department of Cellular and Integrative Physiology, Center for Biomedical Neuroscience, School of Medicine, University of Texas Health Science Center, San Antonio, Texas.,Xiangya School of Medicine, Central South University, Changsha, China
| | - Anna M Taylor
- Department of Cellular and Integrative Physiology, Center for Biomedical Neuroscience, School of Medicine, University of Texas Health Science Center, San Antonio, Texas
| | - Jie Li
- Department of Cellular and Integrative Physiology, Center for Biomedical Neuroscience, School of Medicine, University of Texas Health Science Center, San Antonio, Texas
| | - Manzoor A Bhat
- Department of Cellular and Integrative Physiology, Center for Biomedical Neuroscience, School of Medicine, University of Texas Health Science Center, San Antonio, Texas
| |
Collapse
|
121
|
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.
Collapse
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.
| |
Collapse
|