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Zhu J, Guo X, Ran N, Liang J, Liu F, Liu J, Wang R, Jiang L, Yang D, Liu M. Leukoencephalopathy hypomyelination with brainstem and spinal cord involvement and leg spasticity caused by DARS1 mutations. Front Genet 2023; 13:1009230. [PMID: 36712860 PMCID: PMC9878823 DOI: 10.3389/fgene.2022.1009230] [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: 08/01/2022] [Accepted: 11/15/2022] [Indexed: 01/13/2023] Open
Abstract
Hypomyelination with brainstem and spinal cord involvement and leg spasticity (HBSL), caused by aspartyl-tRNA synthetase (DARS1) gene mutations, is extremely rare, with only a few cases reported worldwide; thus, reports on HBSL treatment are few. In this review, we summarized the clinical manifestations, imaging features, treatment methods, and gene mutations responsible for HBSL based on relevant studies and cases.
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Affiliation(s)
- Jingyi Zhu
- Neurology Department, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Xiaomin Guo
- Neurology Department, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Ningjing Ran
- Neurology Department, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Jingtao Liang
- Neurology Department, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Fuyou Liu
- Neurology Department, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Junyan Liu
- School of Clinical Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Rongyu Wang
- School of Clinical Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Lianyan Jiang
- School of Clinical Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Dongdong Yang
- Neurology Department, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China,*Correspondence: Meijun Liu, ; Dongdong Yang,
| | - Meijun Liu
- Neurology Department, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China,*Correspondence: Meijun Liu, ; Dongdong Yang,
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Nazm Bojnordi M, Ghasemi H, Akbari E. Remyelination after Lysophosphatidyl Choline-Induced Demyelination Is Stimulated by Bone Marrow Stromal Cell-Derived Oligoprogenitor Cell Transplantation. Cells Tissues Organs 2015; 200:300-6. [DOI: 10.1159/000437350] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/02/2015] [Indexed: 11/19/2022] Open
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Regulatory lymphocytes are key factors in MHC-independent resistance to EAE. J Immunol Res 2014; 2014:156380. [PMID: 24868560 PMCID: PMC4020375 DOI: 10.1155/2014/156380] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2013] [Revised: 03/12/2014] [Accepted: 03/13/2014] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND AND OBJECTIVES Resistant and susceptible mouse strains to experimental autoimmune encephalomyelitis (EAE), an inducible demyelinating experimental disease serving as animal model for multiple sclerosis, have been described. We aimed to explore MHC-independent mechanisms inducing resistance to EAE. METHODS For EAE induction, female C57BL/6 (susceptible strain) and CD1 (resistant outbred strain showing heterogeneous MHC antigens) mice were immunized with the 35-55 peptide of myelin oligodendrocyte glycoprotein (MOG35-55). We studied T cell proliferation, regulatory and effector cell subpopulations, intracellular and serum cytokine patterns, and titers of anti-MOG serum antibodies. RESULTS Upon immunization with MOG35-55, T lymphocytes from susceptible mice but not that of resistant strain were capable of proliferating when stimulated with MOG35-55. Accordingly, resistant mice experienced a rise in regulatory B cells (P=0.001) and, to a lower extent, in regulatory T cells (P=0.02) compared with C57BL/6 susceptible mice. As a consequence, MOG35-55-immunized C57BL/6 mice showed higher percentages of CD4+ T cells producing both IFN-gamma (P=0.02) and IL-17 (P=0.009) and higher serum levels of IL-17 (P=0.04) than resistant mice. CONCLUSIONS Expansion of regulatory B and T cells contributes to the induction of resistance to EAE by an MHC-independent mechanism.
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Tzekou A, Fehlings MG. Treatment of spinal cord injury with intravenous immunoglobulin G: preliminary evidence and future perspectives. J Clin Immunol 2014; 34 Suppl 1:S132-8. [PMID: 24722853 PMCID: PMC4050295 DOI: 10.1007/s10875-014-0021-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Accepted: 03/19/2014] [Indexed: 01/18/2023]
Abstract
Neuroinflammation plays an important role in the secondary pathophysiological mechanisms of spinal cord injury (SCI) and can exacerbate the primary trauma and thus worsen recovery. Although some aspects of the immune response are beneficial, it is thought that leukocyte recruitment and activation in the acute phase of injury results in the production of cytotoxic substances that are harmful to the nervous tissue. Therefore, suppression of excessive inflammation in the spinal cord could serve as a therapeutic strategy to attenuate tissue damage. The immunosuppressant methylprednisolone has been used in the setting of SCI, but there are complications which have attenuated the initial enthusiasm. Hence, there is interest in other immunomodulatory approaches, such as intravenous Immunoglobulin G (IVIg). Importantly, IVIg is used clinically for the treatment of several auto-immune neuropathies, such as Guillain-Barre syndrome, chronic inflammatory demyelinating polyneuropathy (CIPD) and Kawasaki disease, with a good safety profile. Thus, it is a promising treatment candidate for SCI. Indeed, IVIg has been shown by our team to attenuate the immune response and result in improved neurobehavioral recovery following cervical SCI in rats through a mechanism that involves the attenuation of neutrophil recruitment and reduction in the levels of cytokines and cytotoxic enzymes Nguyen et al. (J Neuroinflammation 9:224, 2012). Here we review published data in the context of relevant mechanisms of action that have been proposed for IVIg in other conditions. We hope that this discussion will trigger future research to provide supporting evidence for the efficiency and detailed mechanisms of action of this promising drug in the treatment of SCI, and to facilitate its clinical translation.
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Affiliation(s)
- Apostolia Tzekou
- Toronto Western Research Institute and Krembil Neuroscience Centre, University Health Network, University of Toronto, Toronto, Canada
| | - Michael G. Fehlings
- Toronto Western Research Institute and Krembil Neuroscience Centre, University Health Network, University of Toronto, Toronto, Canada
- Division of Neurosurgery, Toronto Western Hospital, University Health Network, University of Toronto, 399 Bathurst St. Suite 4WW-449, Toronto, ON M5T2S8 Canada
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Mecha M, Carrillo-Salinas FJ, Mestre L, Feliú A, Guaza C. Viral models of multiple sclerosis: neurodegeneration and demyelination in mice infected with Theiler's virus. Prog Neurobiol 2013; 101-102:46-64. [PMID: 23201558 PMCID: PMC7117056 DOI: 10.1016/j.pneurobio.2012.11.003] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Revised: 10/30/2012] [Accepted: 11/12/2012] [Indexed: 11/02/2022]
Abstract
Multiple sclerosis (MS) is a complex inflammatory disease of unknown etiology that affects the central nervous system (CNS) white matter, and for which no effective cure exists. Indeed, whether the primary event in MS pathology affects myelin or axons of the CNS remains unclear. Animal models are necessary to identify the immunopathological mechanisms involved in MS and to develop novel therapeutic and reparative approaches. Specifically, viral models of chronic demyelination and axonal damage have been used to study the contribution of viruses in human MS, and they have led to important breakthroughs in our understanding of MS pathology. The Theiler's murine encephalomyelitis virus (TMEV) model is one of the most commonly used MS models, although other viral models are also used, including neurotropic strains of mouse hepatitis virus (MHV) that induce chronic inflammatory demyelination with similar histological features to those observed in MS. This review will discuss the immunopathological mechanisms involved in TMEV-induced demyelinating disease (TMEV-IDD). The TMEV model reproduces a chronic progressive disease due to the persistence of the virus for the entire lifespan in susceptible mice. The evolution and significance of the axonal damage and neuroinflammation, the importance of epitope spread from viral to myelin epitopes, the presence of abortive remyelination and the existence of a brain pathology in addition to the classical spinal cord demyelination, are some of the findings that will be discussed in the context of this TMEV-IDD model. Despite their limitations, viral models remain an important tool to study the etiology of MS, and to understand the clinical and pathological variability associated with this disease.
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Key Words
- ab, antibody
- ag, antigen
- apc, antigen presenting cell
- bbb, blood–brain barrier
- cns, central nervous system
- cox-2, cyclooxygenase-2
- ctl, cytotoxic t lymphocytes
- dpi, days post-infection
- da, daniels strain of theiler's virus
- eae, experimental autoimmune encephalomyelitis
- galc, galactocerebroside
- mbp, myelin basic protein
- mnc, mononuclear cells
- mhc, major histocompatibility complex
- mhv, mouse hepatitis virus
- mog, myelin oligodendrocyte glycoprotein
- ms, multiple sclerosis
- naa, n-acetylaspartate
- no, nitric oxide
- pcr, polymerase chain reaction
- plp, myelin proteolipid protein
- pprs, pattern recognition receptors
- sfv, semliki forest virus
- sv, sindbis virus
- tmev, theiler's murine encephalomyelitis virus
- tmev-idd, theiler's murine encephalomyelitis virus-induced demyelinating disease
- tregs, regulatory t cells
- theiler's virus
- multiple sclerosis
- demyelination
- axonal damage
- neuroinflammation
- spinal cord pathology
- brain pathology
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Affiliation(s)
| | | | | | | | - Carmen Guaza
- Neuroimmunology Group, Functional and System Neurobiology Department, Instituto Cajal, Consejo Superior de Investigaciones Científicas, Avda Dr Arce 37, 28002 Madrid, Spain
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Mix E, Meyer-Rienecker H, Hartung HP, Zettl UK. Animal models of multiple sclerosis--potentials and limitations. Prog Neurobiol 2010; 92:386-404. [PMID: 20558237 PMCID: PMC7117060 DOI: 10.1016/j.pneurobio.2010.06.005] [Citation(s) in RCA: 142] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2010] [Revised: 06/01/2010] [Accepted: 06/07/2010] [Indexed: 12/17/2022]
Abstract
Experimental autoimmune encephalomyelitis (EAE) is still the most widely accepted animal model of multiple sclerosis (MS). Different types of EAE have been developed in order to investigate pathogenetic, clinical and therapeutic aspects of the heterogenic human disease. Generally, investigations in EAE are more suitable for the analysis of immunogenetic elements (major histocompatibility complex restriction and candidate risk genes) and for the study of histopathological features (inflammation, demyelination and degeneration) of the disease than for screening of new treatments. Recent studies in new EAE models, especially in transgenic ones, have in connection with new analytical techniques such as microarray assays provided a deeper insight into the pathogenic cellular and molecular mechanisms of EAE and potentially of MS. For example, it was possible to better delineate the role of soluble pro-inflammatory (tumor necrosis factor-α, interferon-γ and interleukins 1, 12 and 23), anti-inflammatory (transforming growth factor-β and interleukins 4, 10, 27 and 35) and neurotrophic factors (ciliary neurotrophic factor and brain-derived neurotrophic factor). Also, the regulatory and effector functions of distinct immune cell subpopulations such as CD4+ Th1, Th2, Th3 and Th17 cells, CD4+FoxP3+ Treg cells, CD8+ Tc1 and Tc2, B cells and γδ+ T cells have been disclosed in more detail. The new insights may help to identify novel targets for the treatment of MS. However, translation of the experimental results into the clinical practice requires prudence and great caution.
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MESH Headings
- Animals
- Animals, Genetically Modified
- Clinical Trials as Topic
- Disease Models, Animal
- Encephalomyelitis, Autoimmune, Experimental/genetics
- Encephalomyelitis, Autoimmune, Experimental/immunology
- Encephalomyelitis, Autoimmune, Experimental/physiopathology
- Encephalomyelitis, Autoimmune, Experimental/therapy
- Gene Expression Profiling
- History, 19th Century
- History, 20th Century
- History, 21st Century
- Humans
- Microarray Analysis
- Multiple Sclerosis/genetics
- Multiple Sclerosis/immunology
- Multiple Sclerosis/physiopathology
- Multiple Sclerosis/therapy
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Affiliation(s)
- Eilhard Mix
- Department of Neurology, University of Rostock, Germany
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Menge T, Weber MS, Hemmer B, Kieseier BC, von Büdingen HC, Warnke C, Zamvil SS, Boster A, Khan O, Hartung HP, Stüve O. Disease-modifying agents for multiple sclerosis: recent advances and future prospects. Drugs 2009; 68:2445-68. [PMID: 19016573 DOI: 10.2165/0003495-200868170-00004] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Multiple sclerosis (MS) is a chronic autoimmune disease of the CNS. Currently, six medications are approved for immunmodulatory and immunosuppressive treatment of the relapsing disease course and secondary-progressive MS. In the first part of this review, the pathogenesis of MS and its current treatment options are discussed. During the last decade, our understanding of autoimmunity and the pathogenesis of MS has advanced substantially. This has led to the development of a number of compounds, several of which are currently undergoing clinical testing in phase II and III studies. While current treatment options are only available for parenteral administration, several oral compounds are now in clinical trials, including the immunosuppressive agents cladribine and laquinimod. A novel mode of action has been described for fingolimod, another orally available agent, which inhibits egress of activated lymphocytes from draining lymph nodes. Dimethylfumarate exhibits immunomodulatory as well as immunosuppressive activity when given orally. All of these compounds have successfully shown efficacy, at least in regards to the surrogate marker contrast-enhancing lesions on magnetic resonance imaging. Another class of agents that is highlighted in this review are biological agents, namely monoclonal antibodies (mAb) and recombinant fusion proteins. The humanized mAb daclizumab inhibits T-lymphocyte activation via blockade of the interleukin-2 receptor. Alemtuzumab and rituximab deplete leukocytes and B cells, respectively; the fusion protein atacicept inhibits specific B-cell growth factors resulting in reductions in B-cells and plasma cells. These compounds are currently being tested in phase II and III studies in patients with relapsing MS. The concept of neuro-protection and -regeneration has not advanced to a level where specific compounds have entered clinical testing. However, several agents approved for conditions other than MS are highlighted. Finally, with the advent of these highly potent novel therapies, rare, but potentially serious adverse effects have been noted, namely infections and malignancies. These are critically reviewed and put into perspective.
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Affiliation(s)
- Til Menge
- Department of Neurology, Heinrich Heine-University, Düsseldorf, Germany
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Zhou ZH, Zhang Y, Hu YF, Wahl LM, Cisar JO, Notkins AL. The broad antibacterial activity of the natural antibody repertoire is due to polyreactive antibodies. Cell Host Microbe 2008; 1:51-61. [PMID: 18005681 DOI: 10.1016/j.chom.2007.01.002] [Citation(s) in RCA: 162] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2006] [Revised: 12/25/2006] [Accepted: 01/22/2007] [Indexed: 01/05/2023]
Abstract
Polyreactive antibodies bind to a variety of structurally unrelated antigens. The function of these antibodies, however, has remained an enigma, and because of their low binding affinity their biological relevance has been questioned. Using a panel of monoclonal polyreactive antibodies, we showed that these antibodies can bind to both Gram-negative and Gram-positive bacteria and acting through the classical complement pathway can inhibit bacterial growth by lysis, generate anaphylatoxin C5a, enhance phagocytosis, and neutralize the functional activity of endotoxin. Polyreactive antibody-enriched, but not polyreactive antibody-reduced, IgM prepared from normal human serum displays antibacterial activity similar to that of monoclonal polyreactive IgM. We conclude that polyreactive antibodies are a major contributor to the broad antibacterial activity of the natural antibody repertoire.
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Affiliation(s)
- Zhao-Hua Zhou
- Experimental Medicine Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892, USA
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Abstract
Myelination is critical for the normal functioning of the vertebrate nervous system. In the CNS, myelin is produced by oligodendrocytes, and the loss of oligodendrocytes and myelin results in severe functional impairment. Although spontaneous remyelination occurs in chronic demyelinating diseases such as multiple sclerosis, the repair process eventually fails, often resulting in long-term disability. Two distinct general approaches can be considered to promote myelin repair. In one the target is stimulation of the endogenous myelin repair process through delivery of growth factors, and in the second the target is augmentation of the repair process through the delivery of exogenous cells with myelination potential. In both cases, effective treatment of diseases such as multiple sclerosis requires modulation of the immune system, since demyelination is associated with specific immunological activation. Recent studies have shown that some populations of stem cells, including mesenchymal stem cells, have the capacity of promoting endogenous myelin repair and modulating the immune response, prompting an assessment of their use as therapy in demyelinating diseases such as MS. Other types of demyelinating disorders, such as the leukodystrophies, may require multiple repair strategies including both replacement of dysfunctional cells and delivery or supplementation of growth factors, immune modulators or metabolic enzymes. Here we discuss the use of stem cells for the treatment of demyelinating diseases. While the current number of stem cell-based clinical trials for demyelinating diseases is limited, this is likely to increase significantly in the next few years, and a clear understanding of the applicability, limitations and underlying mechanisms mediating stem cell repair is critical.
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Affiliation(s)
- Robert H Miller
- Center for Translational Neuroscience, Department of Neurosciences, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA.
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Abstract
This review examines the mode of action, safety profile and clinical efficacy of some of the most promising new therapeutic strategies for multiple sclerosis. Autologous hematopoietic stem cell transplantation can regenerate a new and tolerant immune system and is a potentially effective rescue therapy in a subset of patients with aggressive forms of MS refractory to approved immunomodulatory and immunosuppressive agents. High-dose cyclophosphamide without stem cell support is suggested to induce prolonged remissions through similar immunological mechanisms with less toxicity. Fingolimod (FTY720) is a novel oral immunomodulating agent that acts through preventing lymphocyte recirculation from lymphoid organs. Monoclonal antibody therapy has provided scientists and clinicians the opportunity to rationally direct the therapeutic intervention against specific molecules. Targeting molecules of the immune system such as CD52 (alemtuzumab), CD25 (daclizumab), VLA-4 (natalizumab) and CD20 (rituximab) have resulted in potent immunomodulatory effects through sometimes unpredicted mechanisms. The potential of immunoglobulins to induce remyelination in the CNS is being investigated in an attempt to develop therapies promoting tissue repair and functional recovery. The evidence supporting the potential of these emerging immunotherapies suggests that strong progress is being made in the development of effective cures for multiple sclerosis.
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Affiliation(s)
- Paolo A. Muraro
- Department of Cellular and Molecular Neuroscience, Imperial College London, SW7 2AZ London, UK
| | - Bibiana Bielekova
- Waddell Center for Multiple Sclerosis, Department of Neurology, University of Cincinnati and The Neuroscience Institute, 45267-0538 Cincinnati, OH
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Kleinschnitz C, Meuth SG, Kieseier BC, Wiendl H. [Update on pathophysiologic and immunotherapeutic approaches for the treatment of multiple sclerosis]. DER NERVENARZT 2007; 78:883-911. [PMID: 17551708 DOI: 10.1007/s00115-007-2261-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Multiple sclerosis (MS) is a chronic disabling disease with significant implications for patients and society. The individual disease course is difficult to predict due to the heterogeneity of clinical presentation and of radiologic and pathologic findings. Although its etiology still remains unknown, the last decade has brought considerable understanding of the underlying pathophysiology of MS. In addition to its acceptance as a prototypic inflammatory autoimmune disorder, recent data reveal the importance of primary and secondary neurodegenerative mechanisms such as oligodendrocyte death, axonal loss, and ion channel dysfunction. The deepened understanding of its immunopathogenesis and the limited effectiveness of currently approved disease-modifying therapies have led to a tremendous number of trials investigating potential new drugs. Emerging treatments take into account the different immunopathological mechanisms and strategies, to protect against axonal damage and promote remyelination. This review provides a compilation of novel immunotherapeutic strategies and recently uncovered aspects of known immunotherapeutic agents. The pathogenetic rationale of these novel drugs for the treatment of MS and accompanying preclinical and clinical data are highlighted.
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Affiliation(s)
- C Kleinschnitz
- Neurologische Klinik und Poliklinik, Universitätsklinikum, Josef-Schneider-Strasse 11, 97080, Würzburg, Germany
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Warrington AE, Bieber AJ, Ciric B, Pease LR, Van Keulen V, Rodriguez M. A recombinant human IgM promotes myelin repair after a single, very low dose. J Neurosci Res 2007; 85:967-76. [PMID: 17304578 DOI: 10.1002/jnr.21217] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
A recombinant human monoclonal IgM, rHIgM22, promotes the synthesis of new myelin when used to treat several animal models of demyelination. rHIgM22 binds to myelin and the surface of oligodendrocytes and accumulates at central nervous system lesions in vivo. The minimal dose of monoclonal IgM required to promote remyelination has a direct bearing on the proposed mechanism of action. A dose ranging study using rHIgM22 was performed in mice with chronic virus-induced demyelination, a model of chronic progressive multiple sclerosis. The lowest tested dose of rHIgM22 effective at promoting spinal cord remyelination was a single 500-ng intraperitoneal bolus injection. A time course study of spinal cord repair performed in chronically demyelinated mice revealed that remyelination plateaued by 5 weeks following treatment with rHIgM22. Two doses of rHIgM22 spaced 5 weeks apart did not increase the extent of remyelination over a single dose. The half-life of rHIgM22 in the mouse systemic circulation was determined to be 15 hr; the human IgM serum concentration was close to zero by 48 hr following antibody administration. We propose that the specificity of rHIgM22 for myelin on living tissue targets the antibody to demyelinated lesions, initiating a long-term reparative effect on the central nervous system.
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Affiliation(s)
- Arthur E Warrington
- Department of Neurology, Mayo Clinic College of Medicine, Mayo Clinic, Rochester, Minnesota 55905, USA.
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Abstract
Remyelination is the phenomenon by which new myelin sheaths are generated around axons in the adult central nervous system (CNS). This follows the pathological loss of myelin in diseases like multiple sclerosis (MS). Remyelination can restore conduction properties to axons (thereby restoring neurological function) and is increasingly believed to exert a neuroprotective role on axons. Remyelination occurs in many MS lesions but becomes increasingly incomplete/inadequate and eventually fails in the majority of lesions and patients. Efforts to understand the causes for this failure of regeneration have fueled research into the biology of remyelination and the complex, interdependent cellular and molecular factors that regulate this process. Examination of the mechanisms of repair of experimental lesions has demonstrated that remyelination occurs in two major phases. The first consists of colonization of lesions by oligodendrocyte progenitor cells (OPCs), the second the differentiation of OPCs into myelinating oligodendrocytes that contact demyelinated axons to generate functional myelin sheaths. Several intracellular and extracellular molecules have been identified that mediate these two phases of repair. Theoretically, the repair of demyelinating lesions can be promoted by enhancing the intrinsic repair process (by providing one or more remyelination-enhancing factors or via immunoglobulin therapy). Alternatively, endogenous repair can be bypassed by introducing myelinogenic cells into demyelinated areas; several cellular candidates have been identified that can mediate repair of experimental demyelinating lesions. Future challenges confronting therapeutic strategies to enhance remyelination will involve the translation of findings from basic science to clinical demyelinating disease.
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Affiliation(s)
- Divya M Chari
- Cambridge Centre for Brain Repair and Veterinary Medicine, University of Cambridge, Cambridge CB3OES, United Kingdom
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Frederick TJ, Miller SD. Future of multiple sclerosis therapy: combining antigen-specific immunotherapy with strategies to promote myelin repair. FUTURE NEUROLOGY 2006. [DOI: 10.2217/14796708.1.4.489] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Persistent CNS inflammation and the failure of myelin repair during multiple sclerosis (MS) trigger a progressive deterioration in neurophysiological function and permanent clinical debilitation. Current treatment consists of immunosuppressive therapies targeted against the immune response, which have only been moderately successful in ameliorating disease relapses and have little or no benefit in slowing disease progression or enhancing remyelination. Recent breakthroughs have revealed new targets and more selective techniques for inhibiting autoreactive T-cell responses and promoting lesion repair in animal models of MS. In light of these new findings and the limitations of current treatments, the authors hypothesize that the future of MS therapy will progress towards the development of a combinatorial therapeutic strategy that consists of specific tolerance of autoreactive T cells, myelin repair and axonal protection.
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Affiliation(s)
- Terra J Frederick
- Northwestern University, Department of Microbiology–Immunology & Interdepartmental Immunobiology Center, Feinberg School of Medicine, IL, USA
| | - Stephen D Miller
- Northwestern University, 6–713 Tarry Building, 303 East Chicago Avenue, IL 60611, USA
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Stangel M, Trebst C. Remyelination strategies: New advancements toward a regenerative treatment in multiple sclerosis. Curr Neurol Neurosci Rep 2006; 6:229-35. [PMID: 16635432 DOI: 10.1007/s11910-006-0010-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Spontaneous remyelination and repair mechanisms in multiple sclerosis are mostly insufficient and contribute to clinical disability. Treatments improving these processes are not yet available but basic research in animal models has led to the proposal of several repair strategies. These include enhancement of the naturally occurring mechanisms, remyelination due to a change of the immune response, and transfer of myelinating cells. Despite the encouraging experimental findings and the constantly increasing knowledge of the molecular mechanisms of remyelination and remyelination failure, there remain many questions before this knowledge can be successfully translated into clinical trials.
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Affiliation(s)
- Martin Stangel
- Department of Neurology, Medical School Hannover, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany.
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