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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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What if? Mouse proteomics after gene inactivation. J Proteomics 2019; 199:102-122. [DOI: 10.1016/j.jprot.2019.03.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2018] [Revised: 03/09/2019] [Accepted: 03/10/2019] [Indexed: 12/17/2022]
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Malheiro AR, Correia B, Ferreira da Silva T, Bessa-Neto D, Van Veldhoven PP, Brites P. Leukodystrophy caused by plasmalogen deficiency rescued by glyceryl 1-myristyl ether treatment. Brain Pathol 2019; 29:622-639. [PMID: 30667116 DOI: 10.1111/bpa.12710] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 01/16/2019] [Indexed: 12/29/2022] Open
Abstract
Plasmalogens are the most abundant form of ether phospholipids in myelin and their deficiency causes Rhizomelic Chondrodysplasia Punctata (RCDP), a severe developmental disorder. Using the Gnpat-knockout (KO) mouse as a model of RCDP, we determined the consequences of a plasmalogen deficiency during myelination and myelin homeostasis in the central nervous system (CNS). We unraveled that the lack of plasmalogens causes a generalized hypomyelination in several CNS regions including the optic nerve, corpus callosum and spinal cord. The defect in myelin content evolved to a progressive demyelination concomitant with generalized astrocytosis and white matter-selective microgliosis. Oligodendrocyte precursor cells (OPC) and mature oligodendrocytes were abundant in the CNS of Gnpat KO mice during the active period of demyelination. Axonal loss was minimal in plasmalogen-deficient mice, although axonal damage was observed in spinal cords from aged Gnpat KO mice. Characterization of the plasmalogen-deficient myelin identified myelin basic protein and septin 7 as early markers of dysmyelination, whereas myelin-associated glycoprotein was associated with the active demyelination phase. Using in vitro myelination assays, we unraveled that the intrinsic capacity of oligodendrocytes to ensheath and initiate membrane wrapping requires plasmalogens. The defect in plasmalogens was rescued with glyceryl 1-myristyl ether [1-O-tetradecyl glycerol (1-O-TDG)], a novel alternative precursor in the plasmalogen biosynthesis pathway. 1-O-TDG treatment rescued myelination in plasmalogen-deficient oligodendrocytes and in mutant mice. Our results demonstrate the importance of plasmalogens for oligodendrocyte function and myelin assembly, and identified a novel strategy to promote myelination in nervous tissue.
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Affiliation(s)
- Ana R Malheiro
- Neurolipid Biology, Instituto de Investigação e Inovação em Saúde - i3S, Instituto de Biologia Molecular e Celular - IBMC e Universidade do Porto, Porto, Portugal.,ICBAS, Instituto Ciências Biomédicas Abel Salazar, Porto, Portugal
| | - Barbara Correia
- Neurolipid Biology, Instituto de Investigação e Inovação em Saúde - i3S, Instituto de Biologia Molecular e Celular - IBMC e Universidade do Porto, Porto, Portugal
| | - Tiago Ferreira da Silva
- Neurolipid Biology, Instituto de Investigação e Inovação em Saúde - i3S, Instituto de Biologia Molecular e Celular - IBMC e Universidade do Porto, Porto, Portugal
| | - Diogo Bessa-Neto
- Neurolipid Biology, Instituto de Investigação e Inovação em Saúde - i3S, Instituto de Biologia Molecular e Celular - IBMC e Universidade do Porto, Porto, Portugal
| | - Paul P Van Veldhoven
- Laboratory of Lipid Biochemistry and Protein Interactions (LIPIT), KU Leuven, Leuven, Belgium
| | - Pedro Brites
- Neurolipid Biology, Instituto de Investigação e Inovação em Saúde - i3S, Instituto de Biologia Molecular e Celular - IBMC e Universidade do Porto, Porto, Portugal
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Baba H, Ishibashi T. The Role of Sulfatides in Axon–Glia Interactions. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1190:165-179. [DOI: 10.1007/978-981-32-9636-7_11] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Erwig MS, Hesse D, Jung RB, Uecker M, Kusch K, Tenzer S, Jahn O, Werner HB. Myelin: Methods for Purification and Proteome Analysis. Methods Mol Biol 2019; 1936:37-63. [PMID: 30820892 DOI: 10.1007/978-1-4939-9072-6_3] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Molecular characterization of myelin is a prerequisite for understanding the normal structure of the axon/myelin-unit in the healthy nervous system and abnormalities in myelin-related disorders. However, reliable molecular profiles necessitate very pure myelin membranes, in particular when considering the power of highly sensitive "omics"-data acquisition methods. Here, we recapitulate the history and recent applications of myelin purification. We then provide our laboratory protocols for the biochemical isolation of a highly pure myelin-enriched fraction from mouse brains and for its proteomic analysis. We also supply methodological modifications when investigating posttranslational modifications, RNA, or myelin from peripheral nerves. Notably, technical advancements in solubilizing myelin are beneficial for gel-based and gel-free myelin proteome analyses. We conclude this article by exemplifying the exceptional power of label-free proteomics in the mass-spectrometric quantification of myelin proteins.
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Affiliation(s)
- Michelle S Erwig
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Goettingen, Germany
| | - Dörte Hesse
- Proteomics Group, Max Planck Institute of Experimental Medicine, Goettingen, Germany
| | - Ramona B Jung
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Goettingen, Germany
| | - Marina Uecker
- Proteomics Group, Max Planck Institute of Experimental Medicine, Goettingen, Germany
| | - Kathrin Kusch
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Goettingen, Germany
| | - Stefan Tenzer
- Institute of Immunology, University Medical Center, Johannes Gutenberg University, Mainz, Germany
| | - Olaf Jahn
- Proteomics Group, Max Planck Institute of Experimental Medicine, Goettingen, Germany.
| | - Hauke B Werner
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Goettingen, Germany.
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Palavicini JP, Wang C, Chen L, Ahmar S, Higuera JD, Dupree JL, Han X. Novel molecular insights into the critical role of sulfatide in myelin maintenance/function. J Neurochem 2016; 139:40-54. [PMID: 27417284 DOI: 10.1111/jnc.13738] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Revised: 06/17/2016] [Accepted: 06/22/2016] [Indexed: 01/19/2023]
Abstract
Cerebroside sulfotransferase (CST) catalyzes the production of sulfatide, a major class of myelin-specific lipids. CST knockout (CST(-/-) ) mice in which sulfatide is completely depleted are born healthy, but display myelin abnormalities and progressive tremors starting at 4-6 weeks of age. Although these phenotypes suggest that sulfatide plays a critical role in myelin maintenance/function, the underlying mechanisms remain largely unknown. We analyzed the major CNS myelin proteins and the major lipids enriched in the myelin in a spatiotemporal manner. We found a one-third reduction of the major compact myelin proteins (myelin basic protein, myelin basic protein, and proteolipid protein, PLP) and an equivalent post-developmental loss of myelin lipids, providing the molecular basis behind the thinner myelin sheaths. Our lipidomics data demonstrated that the observed global reduction of myelin lipid content was not because of an increase of lipid degradation but rather to the reduction of their synthesis by oligodendrocytes. We also showed that sulfatide depletion leads to region-specific effects on non-compact myelin, dramatically affecting the paranode (neurofascin 155) and the major inner tongue myelin protein (myelin-associated glycoprotein). Moreover, we demonstrated that sulfatide promotes the interaction between adjacent PLP extracellular domains, evidenced by a progressive decline of high molecular weight PLP complexes in CST(-/-) mice, providing an explanation at a molecular level regarding the uncompacted myelin sheaths. Finally, we proposed that the dramatic losses of neurofascin 155 and PLP interactions are responsible for the progressive tremors and eventual ataxia. In summary, we unraveled novel molecular insights into the critical role of sulfatide in myelin maintenance/function. Cerebroside sulfotransferase (CST) catalyzes the production of sulfatide, a major class of myelin-specific lipids. CST knockout (CST(-/-) ) mice in which sulfatide is completely depleted are born healthy, but display myelin abnormalities We show in our study that sulfatide depletion leads to losses of myelin proteins and lipids, and impairment of myelin functions, unraveling novel molecular insights into the critical role of sulfatide in myelin maintenance/function.
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Affiliation(s)
- Juan Pablo Palavicini
- Center for Metabolic Origins of Disease, Sanford Burnham Prebys Medical Discovery Institute, Orlando, Florida, USA
| | - Chunyan Wang
- Center for Metabolic Origins of Disease, Sanford Burnham Prebys Medical Discovery Institute, Orlando, Florida, USA
| | - Linyuan Chen
- Center for Metabolic Origins of Disease, Sanford Burnham Prebys Medical Discovery Institute, Orlando, Florida, USA
| | - Sareen Ahmar
- Center for Metabolic Origins of Disease, Sanford Burnham Prebys Medical Discovery Institute, Orlando, Florida, USA
| | - Juan Diego Higuera
- Center for Metabolic Origins of Disease, Sanford Burnham Prebys Medical Discovery Institute, Orlando, Florida, USA
| | - Jeffrey L Dupree
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, Virginia, USA.,Research Division, McGuire Veterans Affairs Medical Center, Richmond, Virginia, USA
| | - Xianlin Han
- Center for Metabolic Origins of Disease, Sanford Burnham Prebys Medical Discovery Institute, Orlando, Florida, USA.
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Abstract
Myelination of axons in the nervous system of vertebrates enables fast, saltatory impulse propagation, one of the best-understood concepts in neurophysiology. However, it took a long while to recognize the mechanistic complexity both of myelination by oligodendrocytes and Schwann cells and of their cellular interactions. In this review, we highlight recent advances in our understanding of myelin biogenesis, its lifelong plasticity, and the reciprocal interactions of myelinating glia with the axons they ensheath. In the central nervous system, myelination is also stimulated by axonal activity and astrocytes, whereas myelin clearance involves microglia/macrophages. Once myelinated, the long-term integrity of axons depends on glial supply of metabolites and neurotrophic factors. The relevance of this axoglial symbiosis is illustrated in normal brain aging and human myelin diseases, which can be studied in corresponding mouse models. Thus, myelinating cells serve a key role in preserving the connectivity and functions of a healthy nervous system.
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Affiliation(s)
- Klaus-Armin Nave
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, D-37075 Göttingen, Germany; ,
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The major myelin-resident protein PLP is transported to myelin membranes via a transcytotic mechanism: involvement of sulfatide. Mol Cell Biol 2014; 35:288-302. [PMID: 25368380 DOI: 10.1128/mcb.00848-14] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Myelin membranes are sheet-like extensions of oligodendrocytes that can be considered membrane domains distinct from the cell's plasma membrane. Consistent with the polarized nature of oligodendrocytes, we demonstrate that transcytotic transport of the major myelin-resident protein proteolipid protein (PLP) is a key element in the mechanism of myelin assembly. Upon biosynthesis, PLP traffics to myelin membranes via syntaxin 3-mediated docking at the apical-surface-like cell body plasma membrane, which is followed by subsequent internalization and transport to the basolateral-surface-like myelin sheet. Pulse-chase experiments, in conjunction with surface biotinylation and organelle fractionation, reveal that following biosynthesis, PLP is transported to the cell body surface in Triton X-100 (TX-100)-resistant microdomains. At the plasma membrane, PLP transiently resides within these microdomains and its lateral dissipation is followed by segregation into 3-[(3-cholamidopropyl)-dimethylammonio]-1-propanesulfonate (CHAPS)-resistant domains, internalization, and subsequent transport toward the myelin membrane. Sulfatide triggers PLP's reallocation from TX-100- into CHAPS-resistant membrane domains, while inhibition of sulfatide biosynthesis inhibits transcytotic PLP transport. Taking these findings together, we propose a model in which PLP transport to the myelin membrane proceeds via a transcytotic mechanism mediated by sulfatide and characterized by a conformational alteration and dynamic, i.e., transient, partitioning of PLP into distinct membrane microdomains involved in biosynthetic and transcytotic transport.
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Ozgen H, Schrimpf W, Hendrix J, de Jonge JC, Lamb DC, Hoekstra D, Kahya N, Baron W. The lateral membrane organization and dynamics of myelin proteins PLP and MBP are dictated by distinct galactolipids and the extracellular matrix. PLoS One 2014; 9:e101834. [PMID: 25003183 PMCID: PMC4086962 DOI: 10.1371/journal.pone.0101834] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Accepted: 06/12/2014] [Indexed: 01/03/2023] Open
Abstract
In the central nervous system, lipid-protein interactions are pivotal for myelin maintenance, as these interactions regulate protein transport to the myelin membrane as well as the molecular organization within the sheath. To improve our understanding of the fundamental properties of myelin, we focused here on the lateral membrane organization and dynamics of peripheral membrane protein 18.5-kDa myelin basic protein (MBP) and transmembrane protein proteolipid protein (PLP) as a function of the typical myelin lipids galactosylceramide (GalC), and sulfatide, and exogenous factors such as the extracellular matrix proteins laminin-2 and fibronectin, employing an oligodendrocyte cell line, selectively expressing the desired galactolipids. The dynamics of MBP were monitored by z-scan point fluorescence correlation spectroscopy (FCS) and raster image correlation spectroscopy (RICS), while PLP dynamics in living cells were investigated by circular scanning FCS. The data revealed that on an inert substrate the diffusion rate of 18.5-kDa MBP increased in GalC-expressing cells, while the diffusion coefficient of PLP was decreased in sulfatide-containing cells. Similarly, when cells were grown on myelination-promoting laminin-2, the lateral diffusion coefficient of PLP was decreased in sulfatide-containing cells. In contrast, PLP's diffusion rate increased substantially when these cells were grown on myelination-inhibiting fibronectin. Additional biochemical analyses revealed that the observed differences in lateral diffusion coefficients of both proteins can be explained by differences in their biophysical, i.e., galactolipid environment, specifically with regard to their association with lipid rafts. Given the persistence of pathological fibronectin aggregates in multiple sclerosis lesions, this fundamental insight into the nature and dynamics of lipid-protein interactions will be instrumental in developing myelin regenerative strategies.
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Affiliation(s)
- Hande Ozgen
- Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Waldemar Schrimpf
- Physical Chemistry, Department of Chemistry, Munich Center for Integrated Protein Science (CiPSM) and Center for Nanoscience (CeNS), Ludwig-Maximilians-Universität, Munich, Germany
| | - Jelle Hendrix
- Physical Chemistry, Department of Chemistry, Munich Center for Integrated Protein Science (CiPSM) and Center for Nanoscience (CeNS), Ludwig-Maximilians-Universität, Munich, Germany
| | - Jenny C. de Jonge
- Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Don C. Lamb
- Physical Chemistry, Department of Chemistry, Munich Center for Integrated Protein Science (CiPSM) and Center for Nanoscience (CeNS), Ludwig-Maximilians-Universität, Munich, Germany
| | - Dick Hoekstra
- Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Nicoletta Kahya
- Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
- * E-mail: (NK) (WB)
| | - Wia Baron
- Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
- * E-mail: (NK) (WB)
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Patzig J, Dworschak MS, Martens AK, Werner HB. Septins in the glial cells of the nervous system. Biol Chem 2014; 395:143-9. [DOI: 10.1515/hsz-2013-0240] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Accepted: 09/13/2013] [Indexed: 01/19/2023]
Abstract
Abstract
The capacity of cytoskeletal septins to mediate diverse cellular processes is related to their ability to assemble as distinct heterooligomers and higher order structures. However, in many cell types the functional relevance of septins is not well understood. This minireview provides a brief overview of our current knowledge about septins in the non-neuronal cells of the vertebrate nervous system, collectively termed ‘glial cells’, i.e., astrocytes, microglia, oligodendrocytes, and Schwann cells. The dysregulation of septins observed in various models of myelin pathology is discussed with respect to implications for hereditary neuralgic amyotrophy (HNA) caused by mutations of the human SEPT9-gene.
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Role of galactosylceramide and sulfatide in oligodendrocytes and CNS myelin: formation of a glycosynapse. ADVANCES IN NEUROBIOLOGY 2014; 9:263-91. [PMID: 25151383 DOI: 10.1007/978-1-4939-1154-7_12] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The two major glycosphingolipids of myelin, galactosylceramide (GalC) and sulfatide (SGC), interact with each other by trans carbohydrate-carbohydrate interactions in vitro. They face each other in the apposed extracellular surfaces of the multilayered myelin sheath produced by oligodendrocytes and could also contact each other between apposed oligodendrocyte processes. Multivalent galactose and sulfated galactose, in the form of GalC/SGC-containing liposomes or silica nanoparticles conjugated to galactose and galactose-3-sulfate, interact with GalC and SGC in the membrane sheets of oligodendrocytes in culture. This interaction causes transmembrane signaling, loss of the cytoskeleton and clustering of membrane domains, similar to the effects of cross-linking by anti-GalC and anti-SGC antibodies. These effects suggest that GalC and SGC could participate in glycosynapses, similar to neural synapses or the immunological synapse, between GSL-enriched membrane domains in apposed oligodendrocyte membranes or extracellular surfaces of mature myelin. Formation of such glycosynapses in vivo would be important for myelination and/or oligodendrocyte/myelin function.
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Sonnino S, Aureli M, Grassi S, Mauri L, Prioni S, Prinetti A. Lipid Rafts in Neurodegeneration and Neuroprotection. Mol Neurobiol 2013; 50:130-48. [DOI: 10.1007/s12035-013-8614-4] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Accepted: 12/08/2013] [Indexed: 11/28/2022]
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Autoimmune T-cell reactivity to myelin proteolipids and glycolipids in multiple sclerosis. Mult Scler Int 2013; 2013:151427. [PMID: 24312732 PMCID: PMC3839122 DOI: 10.1155/2013/151427] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Accepted: 09/12/2013] [Indexed: 11/17/2022] Open
Abstract
Central nervous system (CNS) myelin, the likely major target of autoimmune attack in multiple sclerosis (MS), contains a number of unique components that are potential targets of the attack. Two classes of molecules that are greatly enriched in CNS myelin compared to other parts of the body are certain types of proteolipids and glycolipids. Due to the hydrophobic nature of both of these classes of molecules, they present challenges for use in immunological assays and have therefore been somewhat neglected in studies of T-cell reactivity in MS compared to more soluble molecules such as the myelin basic proteins and the extracellular domain of myelin oligodendrocyte glycoprotein. This review firstly looks at the makeup of CNS myelin, with an emphasis on proteolipids and glycolipids. Next, a retrospective of what is known of T-cell reactivity directed against proteolipids and glycolipids in patients with MS is presented, and the implications of the findings are discussed. Finally, this review considers the question of what would be required to prove a definite role for autoreactivity against proteolipids and glycolipids in the pathogenesis of MS.
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de Monasterio-Schrader P, Jahn O, Tenzer S, Wichert SP, Patzig J, Werner HB. Systematic approaches to central nervous system myelin. Cell Mol Life Sci 2012; 69:2879-94. [PMID: 22441408 PMCID: PMC11114939 DOI: 10.1007/s00018-012-0958-9] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2012] [Accepted: 03/05/2012] [Indexed: 12/11/2022]
Abstract
Rapid signal propagation along vertebrate axons is facilitated by their insulation with myelin, a plasma membrane specialization of glial cells. The recent application of 'omics' approaches to the myelinating cells of the central nervous system, oligodendrocytes, revealed their mRNA signatures, enhanced our understanding of how myelination is regulated, and established that the protein composition of myelin is much more complex than previously thought. This review provides a meta-analysis of the > 1,200 proteins thus far identified by mass spectrometry in biochemically purified central nervous system myelin. Contaminating proteins are surprisingly infrequent according to bioinformatic prediction of subcellular localization and comparison with the transcriptional profile of oligodendrocytes. The integration of datasets also allowed the subcategorization of the myelin proteome into functional groups comprising genes that are coregulated during oligodendroglial differentiation. An unexpectedly large number of myelin-related genes cause-when mutated in humans-hereditary diseases affecting the physiology of the white matter. Systematic approaches to oligodendrocytes and myelin thus provide valuable resources for the molecular dissection of developmental myelination, glia-axonal interactions, leukodystrophies, and demyelinating diseases.
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Affiliation(s)
| | - Olaf Jahn
- Proteomics Group, Max Planck Institute of Experimental Medicine, Göttingen, Germany
- DFG Research Center for Molecular Physiology of the Brain, Göttingen, Germany
| | - Stefan Tenzer
- Institute of Immunology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Sven P. Wichert
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Hermann-Rein-Str. 3, 37075 Göttingen, Germany
| | - Julia Patzig
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Hermann-Rein-Str. 3, 37075 Göttingen, Germany
| | - Hauke B. Werner
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Hermann-Rein-Str. 3, 37075 Göttingen, Germany
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