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Grassi S, Cabitta L, Prioni S, Mauri L, Ciampa MG, Yokoyama N, Iwabuchi K, Zorina Y, Prinetti A. Identification of the Lipid Antigens Recognized by rHIgM22, a Remyelination-Promoting Antibody. Neurochem Res 2023; 48:1783-1797. [PMID: 36695984 DOI: 10.1007/s11064-023-03859-2] [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: 08/20/2022] [Revised: 11/22/2022] [Accepted: 01/09/2023] [Indexed: 01/26/2023]
Abstract
Failure of the immune system to discriminate myelin components from foreign antigens plays a critical role in the pathophysiology of multiple sclerosis. In fact, the appearance of anti-myelin autoantibodies, targeting both proteins and glycolipids, is often responsible for functional alterations in myelin-producing cells in this disease. Nevertheless, some of these antibodies were reported to be beneficial for remyelination. Recombinant human IgM22 (rHIgM22) binds to myelin and to the surface of O4-positive oligodendrocytes, and promotes remyelination in mouse models of chronic demyelination. Interestingly, the identity of the antigen recognized by this antibody remains to be elucidated. The preferential binding of rHIgM22 to sulfatide-positive cells or tissues suggests that sulfatide might be part of the antigen pattern recognized by the antibody, however, cell populations lacking sulfatide expression are also responsive to rHIgM22. Thus, we assessed the binding of rHIgM22 in vitro to purified lipids and lipid extracts from various sources to identify the antigen(s) recognized by this antibody. Our results show that rHIgM22 is indeed able to bind both sulfatide and its deacylated form, whereas no significant binding for other myelin sphingolipids has been detected. Remarkably, binding of rHIgM22 to sulfatide in lipid monolayers can be positively or negatively regulated by the presence of other lipids. Moreover, rHIgM22 also binds to phosphatidylinositol, phosphatidylserine and phosphatidic acid, suggesting that not only sulfatide, but also other membrane lipids might play a role in the binding of rHIgM22 to oligodendrocytes and to other cell types not expressing sulfatide.
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Affiliation(s)
- Sara Grassi
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Via Fratelli Cervi 93, Segrate, 20090, Milan, Italy.
| | - Livia Cabitta
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Via Fratelli Cervi 93, Segrate, 20090, Milan, Italy
| | - Simona Prioni
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Via Fratelli Cervi 93, Segrate, 20090, Milan, Italy
| | - Laura Mauri
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Via Fratelli Cervi 93, Segrate, 20090, Milan, Italy
| | - Maria Grazia Ciampa
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Via Fratelli Cervi 93, Segrate, 20090, Milan, Italy
| | - Noriko Yokoyama
- Institute for Environmental and Gender Specific Medicine, Graduate School of Medicine, Juntendo University, Urayasu, Chiba, Japan
| | - Kazuhisa Iwabuchi
- Institute for Environmental and Gender Specific Medicine, Graduate School of Medicine, Juntendo University, Urayasu, Chiba, Japan
| | | | - Alessandro Prinetti
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Via Fratelli Cervi 93, Segrate, 20090, Milan, Italy
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2
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Matejuk A, Vandenbark AA, Offner H. Cross-Talk of the CNS With Immune Cells and Functions in Health and Disease. Front Neurol 2021; 12:672455. [PMID: 34135852 PMCID: PMC8200536 DOI: 10.3389/fneur.2021.672455] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 04/19/2021] [Indexed: 12/16/2022] Open
Abstract
The immune system's role is much more than merely recognizing self vs. non-self and involves maintaining homeostasis and integrity of the organism starting from early development to ensure proper organ function later in life. Unlike other systems, the central nervous system (CNS) is separated from the peripheral immune machinery that, for decades, has been envisioned almost entirely as detrimental to the nervous system. New research changes this view and shows that blood-borne immune cells (both adaptive and innate) can provide homeostatic support to the CNS via neuroimmune communication. Neurodegeneration is mostly viewed through the lens of the resident brain immune populations with little attention to peripheral circulation. For example, cognition declines with impairment of peripheral adaptive immunity but not with the removal of microglia. Therapeutic failures of agents targeting the neuroinflammation framework (inhibiting immune response), especially in neurodegenerative disorders, call for a reconsideration of immune response contributions. It is crucial to understand cross-talk between the CNS and the immune system in health and disease to decipher neurodestructive and neuroprotective immune mechanisms for more efficient therapeutic strategies.
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Affiliation(s)
- Agata Matejuk
- Department of Immunology, Collegium Medicum, University of Zielona Góra, Zielona Góra, Poland
| | - Arthur A Vandenbark
- Neuroimmunology Research, VA Portland Health Care System, Portland, OR, United States.,Department of Neurology, Oregon Health and Science University, Portland, OR, United States.,Department of Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, OR, United States
| | - Halina Offner
- Neuroimmunology Research, VA Portland Health Care System, Portland, OR, United States.,Department of Neurology, Oregon Health and Science University, Portland, OR, United States.,Department of Anesthesiology and Perioperative Medicine, Oregon Health and Science University, Portland, OR, United States
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3
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Avrameas S, Alexopoulos H, Moutsopoulos HM. Natural Autoantibodies: An Undersugn Hero of the Immune System and Autoimmune Disorders-A Point of View. Front Immunol 2018; 9:1320. [PMID: 29946320 PMCID: PMC6005843 DOI: 10.3389/fimmu.2018.01320] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 05/28/2018] [Indexed: 12/25/2022] Open
Affiliation(s)
- Stratis Avrameas
- Laboratory of Immunology, Hellenic Pasteur Institute, Athens, Greece
| | - Haris Alexopoulos
- Department of Pathophysiology, Faculty of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - Harry M Moutsopoulos
- Department of Pathophysiology, Faculty of Medicine, National and Kapodistrian University of Athens, Athens, Greece.,Academy of Athens, Athens, Greece
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4
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Ulndreaj A, Tzekou A, Mothe AJ, Siddiqui AM, Dragas R, Tator CH, Torlakovic EE, Fehlings MG. Characterization of the Antibody Response after Cervical Spinal Cord Injury. J Neurotrauma 2016; 34:1209-1226. [PMID: 27775474 DOI: 10.1089/neu.2016.4498] [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] [Indexed: 01/09/2023] Open
Abstract
The immune system plays a critical and complex role in the pathobiology of spinal cord injury (SCI), exerting both beneficial and detrimental effects. Increasing evidence suggests that there are injury level-dependent differences in the immune response to SCI. Patients with traumatic SCI have elevated levels of circulating autoantibodies against components of the central nervous system, but the role of these antibodies in SCI outcomes remains unknown. In rodent models of mid-thoracic SCI, antibody-mediated autoimmunity appears to be detrimental to recovery. However, whether autoantibodies against the spinal cord are generated following cervical SCI (cSCI), the most common level of injury in humans, remains undetermined. To address this knowledge gap, we investigated the antibody responses following cSCI in a rat model of injury. We found increased immunoglobulin G (IgG) and IgM antibodies in the spinal cord in the subacute phase of injury (2 weeks), but not in more chronic phases (10 and 20 weeks). At 2 weeks post-cSCI, antibodies were detected at the injury epicenter and co-localized with the astroglial scar and neurons of the ventral horn. These increased levels of antibodies corresponded with enhanced activation of immune responses in the spleen. Higher counts of antibody-secreting cells were observed in the spleen of injured rats. Further, increased levels of secreted IgG antibodies and enhanced proliferation of T-cells in splenocyte cultures from injured rats were found. These findings suggest the potential development of autoantibody responses following cSCI in the rat. The impact of the post-traumatic antibody responses on functional outcomes of cSCI is a critical topic that requires further investigation.
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Affiliation(s)
- Antigona Ulndreaj
- 1 Division of Genetics and Development, Toronto Western Research Institute and University of Toronto Spinal Program, Krembil Neuroscience Center, University Health Network , Toronto, Ontario, Canada .,2 Institute of Medical Science, Faculty of Medicine, University of Toronto , Toronto, Ontario, Canada
| | - Apostolia Tzekou
- 1 Division of Genetics and Development, Toronto Western Research Institute and University of Toronto Spinal Program, Krembil Neuroscience Center, University Health Network , Toronto, Ontario, Canada
| | - Andrea J Mothe
- 1 Division of Genetics and Development, Toronto Western Research Institute and University of Toronto Spinal Program, Krembil Neuroscience Center, University Health Network , Toronto, Ontario, Canada
| | - Ahad M Siddiqui
- 1 Division of Genetics and Development, Toronto Western Research Institute and University of Toronto Spinal Program, Krembil Neuroscience Center, University Health Network , Toronto, Ontario, Canada
| | - Rachel Dragas
- 1 Division of Genetics and Development, Toronto Western Research Institute and University of Toronto Spinal Program, Krembil Neuroscience Center, University Health Network , Toronto, Ontario, Canada .,2 Institute of Medical Science, Faculty of Medicine, University of Toronto , Toronto, Ontario, Canada
| | - Charles H Tator
- 1 Division of Genetics and Development, Toronto Western Research Institute and University of Toronto Spinal Program, Krembil Neuroscience Center, University Health Network , Toronto, Ontario, Canada .,2 Institute of Medical Science, Faculty of Medicine, University of Toronto , Toronto, Ontario, Canada .,3 Department of Surgery, University of Toronto , Toronto, Ontario, Canada .,4 University of Toronto Spine Program, University of Toronto , Toronto, Ontario, Canada
| | - Emina E Torlakovic
- 5 Department of Laboratory Hematology, University of Toronto , Toronto, Ontario, Canada
| | - Michael G Fehlings
- 1 Division of Genetics and Development, Toronto Western Research Institute and University of Toronto Spinal Program, Krembil Neuroscience Center, University Health Network , Toronto, Ontario, Canada .,2 Institute of Medical Science, Faculty of Medicine, University of Toronto , Toronto, Ontario, Canada .,3 Department of Surgery, University of Toronto , Toronto, Ontario, Canada .,4 University of Toronto Spine Program, University of Toronto , Toronto, Ontario, Canada
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5
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Winter M, Baksmeier C, Steckel J, Barman S, Malviya M, Harrer-Kuster M, Hartung HP, Goebels N. Dose-dependent inhibition of demyelination and microglia activation by IVIG. Ann Clin Transl Neurol 2016; 3:828-843. [PMID: 27844029 PMCID: PMC5099529 DOI: 10.1002/acn3.326] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 04/25/2016] [Accepted: 05/09/2016] [Indexed: 12/31/2022] Open
Abstract
Objective Intravenous immunoglobulin (IVIG) is an established treatment for numerous autoimmune conditions. Clinical trials of IVIG for multiple sclerosis, using diverse dose regimens, yielded controversial results. The aim of this study is to dissect IVIG effector mechanisms on demyelination in an ex vivo model of the central nervous system (CNS)‐immune interface. Methods Using organotypic cerebellar slice cultures (OSC) from transgenic mice expressing green fluorescent protein (GFP) in oligodendrocytes/myelin, we induced extensive immune‐mediated demyelination and oligodendrocyte loss with an antibody specific for myelin oligodendrocyte glycoprotein (MOG) and complement. Protective IVIG effects were assessed by live imaging of GFP expression, confocal microscopy, immunohistochemistry, gene expression analysis and flow cytometry. Results IVIG protected OSC from demyelination in a dose‐dependent manner, which was at least partly attributed to interference with complement‐mediated oligodendroglia damage, while binding of the anti‐MOG antibody was not prevented. Staining with anti‐CD68 antibodies and flow cytometry confirmed that IVIG prevented microglia activation and oligodendrocyte death, respectively. Equimolar IVIG‐derived Fab fragments or monoclonal IgG did not protect OSC, while Fc fragments derived from a polyclonal mixture of human IgG were at least as potent as intact IVIG. Interpretation Both intact IVIG and Fc fragments exert a dose‐dependent protective effect on antibody‐mediated CNS demyelination and microglia activation by interfering with the complement cascade and, presumably, interacting with local immune cells. Although this experimental model lacks blood–brain barrier and peripheral immune components, our findings warrant further studies on optimal dose finding and alternative modes of application to enhance local IVIG concentrations at the site of tissue damage.
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Affiliation(s)
- Meike Winter
- Department of Neurology, Medical Faculty Heinrich-Heine-University Duesseldorf Moorenstr. 5 D-40225 Duesseldorf Germany
| | - Christine Baksmeier
- Department of Neurology, Medical Faculty Heinrich-Heine-University Duesseldorf Moorenstr. 5 D-40225 Duesseldorf Germany
| | - Julia Steckel
- Department of Neurology, Medical Faculty Heinrich-Heine-University Duesseldorf Moorenstr. 5 D-40225 Duesseldorf Germany
| | - Sumanta Barman
- Department of Neurology, Medical Faculty Heinrich-Heine-University Duesseldorf Moorenstr. 5 D-40225 Duesseldorf Germany
| | - Manish Malviya
- Department of Neurology, Medical Faculty Heinrich-Heine-University Duesseldorf Moorenstr. 5D-40225 Duesseldorf Germany; Present address: CPTP, Centre Physiopathologie de Toulouse-Purpan INSERM U1043 - CNRS UMR 5282-Université Toulouse III Toulouse France
| | - Melanie Harrer-Kuster
- University of Zuerich, Clinical Neuroimmunology Zuerich Switzerland; Present address: Abb Vie AG Baar Switzerland
| | - Hans-Peter Hartung
- Department of Neurology, Medical Faculty Heinrich-Heine-University Duesseldorf Moorenstr. 5 D-40225 Duesseldorf Germany
| | - Norbert Goebels
- Department of Neurology, Medical Faculty Heinrich-Heine-University Duesseldorf Moorenstr. 5 D-40225 Duesseldorf Germany
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Harlow DE, Honce JM, Miravalle AA. Remyelination Therapy in Multiple Sclerosis. Front Neurol 2015; 6:257. [PMID: 26696956 PMCID: PMC4674562 DOI: 10.3389/fneur.2015.00257] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Accepted: 11/23/2015] [Indexed: 01/10/2023] Open
Abstract
Multiple sclerosis (MS) is an immune-mediated disorder of the central nervous system that results in destruction of the myelin sheath that surrounds axons and eventual neurodegeneration. Current treatments approved for the treatment of relapsing forms of MS target the aberrant immune response and successfully reduce the severity of attacks and frequency of relapses. Therapies are still needed that can repair damage particularly for the treatment of progressive forms of MS for which current therapies are relatively ineffective. Remyelination can restore neuronal function and prevent further neuronal loss and clinical disability. Recent advancements in our understanding of the molecular and cellular mechanisms regulating myelination, as well as the development of high-throughput screens to identify agents that enhance myelination, have lead to the identification of many potential remyelination therapies currently in preclinical and early clinical development. One problem that has plagued the development of treatments to promote remyelination is the difficulty in assessing remyelination in patients with current imaging techniques. Powerful new imaging technologies are making it easier to discern remyelination in patients, which is critical for the assessment of these new therapeutic strategies during clinical trials. This review will summarize what is currently known about remyelination failure in MS, strategies to overcome this failure, new therapeutic treatments in the pipeline for promoting remyelination in MS patients, and new imaging technologies for measuring remyelination in patients.
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Affiliation(s)
- Danielle E Harlow
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus , Aurora, CO , USA
| | - Justin M Honce
- Department of Radiology, University of Colorado Anschutz Medical Campus , Aurora, CO , USA
| | - Augusto A Miravalle
- Department of Neurology, University of Colorado Anschutz Medical Campus , Aurora, CO , USA
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7
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Sex differences in the early life correlates of natural antibody concentrations. J Dev Orig Health Dis 2015; 6:501-11. [PMID: 26279187 DOI: 10.1017/s2040174415001373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Innate-like B1a lymphocytes arise from long-lived progenitors produced exclusively by fetal stem cells. Any insults coinciding with this early lymphopoietic wave could have a permanent impact on the B1a population and its unique protein products, the natural antibodies (NAb). We investigated early life nutritional influences on NAb concentrations of pre-adolescent children (n=290) in rural Nepal for whom we had extensive information on exposures from pregnancy and early infancy. Infant size and growth were strongly associated with NAb concentrations at 9-13 years of age among males (e.g., for neonatal weight: βBOYS=0.43; P<0.001), but not females (e.g., for neonatal weight: βGIRLS=-0.16; P=0.26). In females, season of birth was associated with NAb concentrations, with marked reductions among girls born during the pre-monsoon (March-May; βGIRLS=-0.39; P=0.01) and pre-harvest (September-November; βGIRLS=-0.35; P=0.03) seasons. Our findings suggest that nutritional or other environmental influences on immune development may vary by sex, with potential consequences for immune function during infancy and long-term risk of immune-mediated disease.
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8
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Kremer D, Hartung HP, Stangel M, Küry P. [New therapeutic strategies for remyelination in multiple sclerosis]. DER NERVENARZT 2015; 86:934-46. [PMID: 26122637 DOI: 10.1007/s00115-014-4249-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Multiple sclerosis (MS) is characterized by oligodendrocyte death and myelin sheath destruction of the central nervous system (CNS) in response to autoinflammatory processes. Besides demyelination axonal degeneration constitutes the second histopathological hallmark of this disease. A large number of immunomodulatory and targeted immunosuppression treatments have been approved for relapsing remitting (RR) MS where they effectively reduce relapse rates; however, currently no treatment options exist to repair injured axonal tracts or myelin damage that accumulates over time particularly in progressive MS. In light of the growing available therapeutic repertoire of highly potent immunomodulatory medications there is an increasing interest in the development of therapies aimed at neutralizing neurodegenerative damage. Endogenous remyelination processes occur mainly as a result of oligodendrocyte precursor cell (OPC) activation, recruitment and maturation; however, this repair activity appears to be limited and increasingly fails during disease progression. Based on these observations OPCs are considered as promising targets for the regenerative treatment of all stages of MS. This article presents an overview of approved medications with a suggested role in regeneration, regenerative treatments that are currently being tested in clinical trials, as well as promising future therapeutic approaches derived from basic glial cell research aiming at the promotion of the endogenous repair activity of the brain.
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Affiliation(s)
- D Kremer
- Neurologische Klinik, Medizinische Fakultät, Heinrich-Heine-Universität, Moorenstr. 5, 40225, Düsseldorf , Deutschland
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9
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Tzekova N, Heinen A, Bunk S, Hermann C, Hartung HP, Reipert B, Küry P. Immunoglobulins stimulate cultured Schwann cell maturation and promote their potential to induce axonal outgrowth. J Neuroinflammation 2015; 12:107. [PMID: 26022648 PMCID: PMC4450464 DOI: 10.1186/s12974-015-0331-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 05/20/2015] [Indexed: 02/06/2023] Open
Abstract
Background Schwann cells are the myelinating glial cells of the peripheral nervous system and exert important regenerative functions revealing them as central repair components of many peripheral nerve pathologies. Intravenous immunoglobulins (IVIG) are widely used to treat autoimmune and inflammatory diseases including immune-mediated neuropathies. Nevertheless, promotion of peripheral nerve regeneration is currently an unmet therapeutical goal. We therefore examined whether immunoglobulins affect glial cell homeostasis, differentiation, and Schwann cell dependent nerve regenerative processes. Methods The responses of different primary Schwann cell culture models to IVIG were investigated: immature or differentiation competent Schwann cells, myelinating neuron/glial cocultures, and dorsal root ganglion explants. Immature or differentiating Schwann cells were used to study cellular proliferation, morphology, and gene/protein expression. Myelination rates were determined using myelinating neuron/glia cocultures, whereas axonal outgrowth was assessed using non-myelinating dorsal root ganglion explants. Results We found that IVIG specifically bind to Schwann cells and detected CD64 Fc receptor expression on their surface. In response to IVIG binding, Schwann cells reduced proliferation rates and accelerated growth of cellular protrusions. Furthermore, we observed that IVIG treatment transiently boosts myelin gene expression and myelination-related signaling pathways of immature cells, whereas in differentiating Schwann cells, myelin expression is enhanced on a long-term scale. Importantly, myelin gene upregulation was not detected upon application of IgG1 control antibodies. In addition, we demonstrate for the first time that Schwann cells secrete interleukin-18 upon IVIG stimulation and that this cytokine instructs these cells to promote axonal growth. Conclusions We conclude that IVIG can positively influence the Schwann cell differentiation process and that it enhances their regenerative potential.
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Affiliation(s)
- Nevena Tzekova
- Department of Neurology, Medical Faculty, Heinrich-Heine-University, Moorenstrasse 5, 40225, Düsseldorf, Germany.
| | - André Heinen
- Department of Neurology, Medical Faculty, Heinrich-Heine-University, Moorenstrasse 5, 40225, Düsseldorf, Germany.
| | - Sebastian Bunk
- Department of Immunology, Baxter Innovations GmbH, Vienna, Austria.
| | - Corinna Hermann
- Medical Affairs EMEA, Baxter Innovations GmbH, Vienna, Austria.
| | - Hans-Peter Hartung
- Department of Neurology, Medical Faculty, Heinrich-Heine-University, Moorenstrasse 5, 40225, Düsseldorf, Germany.
| | - Birgit Reipert
- Department of Immunology, Baxter Innovations GmbH, Vienna, Austria.
| | - Patrick Küry
- Department of Neurology, Medical Faculty, Heinrich-Heine-University, Moorenstrasse 5, 40225, Düsseldorf, Germany.
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Aureli M, Grassi S, Prioni S, Sonnino S, Prinetti A. Lipid membrane domains in the brain. Biochim Biophys Acta Mol Cell Biol Lipids 2015; 1851:1006-16. [PMID: 25677824 DOI: 10.1016/j.bbalip.2015.02.001] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Revised: 01/29/2015] [Accepted: 02/01/2015] [Indexed: 12/28/2022]
Abstract
The brain is characterized by the presence of cell types with very different functional specialization, but with the common trait of a very high complexity of structures originated by their plasma membranes. Brain cells bear evident membrane polarization with the creation of different morphological and functional subcompartments, whose formation, stabilization and function require a very high level of lateral order within the membrane. In other words, the membrane specialization of brain cells implies the presence of distinct membrane domains. The brain is the organ with the highest enrichment in lipids like cholesterol, glycosphingolipids, and the most recently discovered brain membrane lipid, phosphatidylglucoside, whose collective behavior strongly favors segregation within the membrane leading to the formation of lipid-driven membrane domains. Lipid-driven membrane domains function as dynamic platforms for signal transduction, protein processing, and membrane turnover. Essential events involved in the development and in the maintenance of the functional integrity of the brain depend on the organization of lipid-driven membrane domains, and alterations in lipid homeostasis, leading to deranged lipid-driven membrane organization, are common in several major brain diseases. In this review, we summarize the forces behind the formation of lipid membrane domains and their biological roles in different brain cells. This article is part of a Special Issue entitled Brain Lipids.
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Affiliation(s)
- Massimo Aureli
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Italy
| | - Sara Grassi
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Italy
| | - Simona Prioni
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Italy
| | - Sandro Sonnino
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Italy
| | - Alessandro Prinetti
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Italy.
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11
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Kremer D, Küry P, Dutta R. Promoting remyelination in multiple sclerosis: current drugs and future prospects. Mult Scler 2015; 21:541-9. [PMID: 25623245 DOI: 10.1177/1352458514566419] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Myelin destruction due to inflammatory oligodendrocyte cell damage or death in conjunction with axonal degeneration are among the major histopathological hallmarks of multiple sclerosis (MS). The majority of available immunomodulatory medications for MS are approved for relapsing-remitting (RR) MS, for which they reduce relapse rate, MRI measures of inflammation, and the accumulation of disability. These medications are, however, of little benefit during progressive MS where axonal degeneration following demyelination outweighs inflammation. This has sparked great interest in the development of new remyelination therapies aimed at reversing the neurodegenerative damage observed in this disease. Remyelination as a result of oligodendrocyte production from oligodendrocyte precursor cells (OPCs) is considered a promising potential target for the treatment of all stages of MS. In this review we present an overview of a) approved medications (some of them FDA-and EMA-approved for other diseases) with a proposed role in regeneration, b) regenerative treatments under investigation in clinical trials, and c) promising future therapeutic approaches aiming specifically at facilitating endogenous repair.
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Affiliation(s)
- David Kremer
- Department of Neurology, Medical Faculty, University of Düsseldorf, Germany/Department of Neurosciences, Lerner Research Institute, USA
| | - Patrick Küry
- Department of Neurology, Medical Faculty, University of Düsseldorf, Germany
| | - Ranjan Dutta
- Department of Neurosciences, Lerner Research Institute, USA
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12
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Grönwall C, Silverman GJ. Natural IgM: beneficial autoantibodies for the control of inflammatory and autoimmune disease. J Clin Immunol 2014; 34 Suppl 1:S12-21. [PMID: 24691998 DOI: 10.1007/s10875-014-0025-4] [Citation(s) in RCA: 119] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Accepted: 03/19/2014] [Indexed: 12/13/2022]
Abstract
Natural IgM are highly represented in the circulation at birth, and these often autoreactive antibodies have been postulated to have innate-like properties and play crucial roles in apoptotic cell clearance, tissue homeostasis, and immune modulation. This review summarizes the known properties of these IgM autoantibodies, and the evidence that these anti-apoptotic cell IgM natural antibodies can regulate inflammatory responses through ancient pathways of the innate immune system that first arose long before the initial emergence of the adaptive immune system. While the regulatory contributions of these natural IgM autoantibodies are certainly not an essential and fundamental component of host defenses, these provide an additional layer to further protect the host. More importantly, these IgM antibody responses are highly inducible and their up-regulation can be a powerful means for the host to survive in a setting of chronic inflammation. The observed beneficial clinical associations for cardiovascular disease and autoimmunity, as well as opportunities for potential therapeutic implications are discussed.
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Affiliation(s)
- Caroline Grönwall
- Department of Medicine, New York University School of Medicine, New York, NY, 10016, USA,
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