1
|
Mitra S, Harvey-Jones K, Kraev I, Verma V, Meehan C, Mintoft A, Norris G, Campbell E, Tucker K, Robertson NJ, Hristova M, Lange S. The Extracellular Vesicle Citrullinome and Signature in a Piglet Model of Neonatal Seizures. Int J Mol Sci 2023; 24:11529. [PMID: 37511288 PMCID: PMC10380774 DOI: 10.3390/ijms241411529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Revised: 07/09/2023] [Accepted: 07/14/2023] [Indexed: 07/30/2023] Open
Abstract
Neonatal seizures are commonly associated with acute perinatal brain injury, while understanding regarding the downstream molecular pathways related to seizures remains unclear. Furthermore, effective treatment and reliable biomarkers are still lacking. Post-translational modifications can contribute to changes in protein function, and post-translational citrullination, which is caused by modification of arginine to citrulline via the calcium-mediated activation of the peptidylarginine deiminase (PAD) enzyme family, is being increasingly linked to neurological injury. Extracellular vesicles (EVs) are lipid-bilayer structures released from cells; they can be isolated from most body fluids and act as potential liquid biomarkers for disease conditions and response to treatment. As EVs carry a range of genetic and protein cargo that can be characteristic of pathological processes, the current study assessed modified citrullinated protein cargo in EVs isolated from plasma and CSF in a piglet neonatal seizure model, also following phenobarbitone treatment. Our findings provide novel insights into roles for PAD-mediated changes on EV signatures in neonatal seizures and highlight the potential of plasma- and CSF-EVs to monitor responses to treatment.
Collapse
Affiliation(s)
- Subhabrata Mitra
- Department of Neonatology, Institute for Women's Health, University College London, London WC1E 6BT, UK
| | - Kelly Harvey-Jones
- Department of Neonatology, Institute for Women's Health, University College London, London WC1E 6BT, UK
| | - Igor Kraev
- Electron Microscopy Suite, Faculty of Science, Technology, Engineering and Mathematics, Open University, Milton Keynes MK7 6AA, UK
| | - Vinita Verma
- Department of Neonatology, Institute for Women's Health, University College London, London WC1E 6BT, UK
| | - Christopher Meehan
- Department of Neonatology, Institute for Women's Health, University College London, London WC1E 6BT, UK
| | - Alison Mintoft
- Department of Neonatology, Institute for Women's Health, University College London, London WC1E 6BT, UK
| | - Georgina Norris
- Department of Neonatology, Institute for Women's Health, University College London, London WC1E 6BT, UK
| | - Ellie Campbell
- Department of Neonatology, Institute for Women's Health, University College London, London WC1E 6BT, UK
| | - Katie Tucker
- Department of Neonatology, Institute for Women's Health, University College London, London WC1E 6BT, UK
| | - Nicola J Robertson
- Department of Neonatology, Institute for Women's Health, University College London, London WC1E 6BT, UK
| | - Mariya Hristova
- Perinatal Brain Repair Group, Department of Neonatology, UCL Institute for Women's Health, London WC1E 6HU, UK
| | - Sigrun Lange
- Perinatal Brain Repair Group, Department of Neonatology, UCL Institute for Women's Health, London WC1E 6HU, UK
- Tissue Architecture and Regeneration Research Group, School of Life Sciences, University of Westminster, London W1W 6UW, UK
- Pathobiology and Extracellular Vesicle Research Group, School of Life Sciences, University of Westminster, London W1W 6UW, UK
| |
Collapse
|
2
|
Timmermann A, Tascio D, Jabs R, Boehlen A, Domingos C, Skubal M, Huang W, Kirchhoff F, Henneberger C, Bilkei-Gorzo A, Seifert G, Steinhäuser C. Dysfunction of NG2 glial cells affects neuronal plasticity and behavior. Glia 2023; 71:1481-1501. [PMID: 36802096 DOI: 10.1002/glia.24352] [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: 12/01/2022] [Revised: 01/18/2023] [Accepted: 01/19/2023] [Indexed: 02/20/2023]
Abstract
NG2 glia represents a distinct type of macroglial cells in the CNS and is unique among glia because they receive synaptic input from neurons. They are abundantly present in white and gray matter. While the majority of white matter NG2 glia differentiates into oligodendrocytes, the physiological impact of gray matter NG2 glia and their synaptic input are still ill defined. Here, we asked whether dysfunctional NG2 glia affect neuronal signaling and behavior. We generated mice with inducible deletion of the K+ channel Kir4.1 in NG2 glia and performed comparative electrophysiological, immunohistochemical, molecular and behavioral analyses. Kir4.1 was deleted at postnatal day 23-26 (recombination efficiency about 75%) and mice were investigated 3-8 weeks later. Notably, these mice with dysfunctional NG2 glia demonstrated improved spatial memory as revealed by testing new object location recognition while working and social memory remained unaffected. Focussing on the hippocampus, we found that loss of Kir4.1 potentiated synaptic depolarizations of NG2 glia and stimulated the expression of myelin basic protein while proliferation and differentiation of hippocampal NG2 glia remained largely unaffected. Mice with targeted deletion of the K+ channel in NG2 glia showed impaired long-term potentiation at CA3-CA1 synapses, which could be fully rescued by extracellular application of a TrkB receptor agonist. Our data demonstrate that proper NG2 glia function is important for normal brain function and behavior.
Collapse
Affiliation(s)
- Aline Timmermann
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Dario Tascio
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Ronald Jabs
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Anne Boehlen
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Catia Domingos
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Magdalena Skubal
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Wenhui Huang
- Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland, Homburg, Germany
| | - Frank Kirchhoff
- Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland, Homburg, Germany
| | - Christian Henneberger
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany.,German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany.,Institute of Neurology, University College London, London, UK
| | - Andras Bilkei-Gorzo
- Institute of Molecular Psychiatry, Medical Faculty, University of Bonn, Bonn, Germany
| | - Gerald Seifert
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Christian Steinhäuser
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| |
Collapse
|
3
|
Leal AF, Suarez DA, Echeverri-Peña OY, Albarracín SL, Alméciga-Díaz CJ, Espejo-Mojica ÁJ. Sphingolipids and their role in health and disease in the central nervous system. Adv Biol Regul 2022; 85:100900. [PMID: 35870382 DOI: 10.1016/j.jbior.2022.100900] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 06/21/2022] [Accepted: 07/11/2022] [Indexed: 12/22/2022]
Abstract
Sphingolipids (SLs) are lipids derived from sphingosine, and their metabolism involves a broad and complex network of reactions. Although SLs are widely distributed in the body, it is well known that they are present in high concentrations within the central nervous system (CNS). Under physiological conditions, their abundance and distribution in the CNS depend on brain development and cell type. Consequently, SLs metabolism impairment may have a significant impact on the normal CNS function, and has been associated with several disorders, including sphingolipidoses, Parkinson's, and Alzheimer's. This review summarizes the main SLs characteristics and current knowledge about synthesis, catabolism, regulatory pathways, and their role in physiological and pathological scenarios in the CNS.
Collapse
Affiliation(s)
- Andrés Felipe Leal
- Institute for the Study of Inborn Errors of Metabolism, Faculty of Science, Pontificia Universidad Javeriana, Bogotá D.C, Colombia
| | - Diego A Suarez
- Institute for the Study of Inborn Errors of Metabolism, Faculty of Science, Pontificia Universidad Javeriana, Bogotá D.C, Colombia
| | - Olga Yaneth Echeverri-Peña
- Institute for the Study of Inborn Errors of Metabolism, Faculty of Science, Pontificia Universidad Javeriana, Bogotá D.C, Colombia
| | - Sonia Luz Albarracín
- Nutrition and Biochemistry Department, Faculty of Science, Pontificia Universidad Javeriana, Bogotá D.C, Colombia
| | - Carlos Javier Alméciga-Díaz
- Institute for the Study of Inborn Errors of Metabolism, Faculty of Science, Pontificia Universidad Javeriana, Bogotá D.C, Colombia.
| | - Ángela Johana Espejo-Mojica
- Institute for the Study of Inborn Errors of Metabolism, Faculty of Science, Pontificia Universidad Javeriana, Bogotá D.C, Colombia.
| |
Collapse
|
4
|
Meschkat M, Steyer AM, Weil MT, Kusch K, Jahn O, Piepkorn L, Agüi-Gonzalez P, Phan NTN, Ruhwedel T, Sadowski B, Rizzoli SO, Werner HB, Ehrenreich H, Nave KA, Möbius W. White matter integrity in mice requires continuous myelin synthesis at the inner tongue. Nat Commun 2022; 13:1163. [PMID: 35246535 PMCID: PMC8897471 DOI: 10.1038/s41467-022-28720-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 01/24/2022] [Indexed: 12/18/2022] Open
Abstract
Myelin, the electrically insulating sheath on axons, undergoes dynamic changes over time. However, it is composed of proteins with long lifetimes. This raises the question how such a stable structure is renewed. Here, we study the integrity of myelinated tracts after experimentally preventing the formation of new myelin in the CNS of adult mice, using an inducible Mbp null allele. Oligodendrocytes survive recombination, continue to express myelin genes, but they fail to maintain compacted myelin sheaths. Using 3D electron microscopy and mass spectrometry imaging we visualize myelin-like membranes failing to incorporate adaxonally, most prominently at juxta-paranodes. Myelinoid body formation indicates degradation of existing myelin at the abaxonal side and the inner tongue of the sheath. Thinning of compact myelin and shortening of internodes result in the loss of about 50% of myelin and axonal pathology within 20 weeks post recombination. In summary, our data suggest that functional axon-myelin units require the continuous incorporation of new myelin membranes. Myelin is formed of proteins of long half-lives. The mechanisms of renewal of such a stable structure are unclear. Here, the authors show that myelin integrity requires continuous myelin synthesis at the inner tongue, contributing to the maintenance of a functional axon-myelin unit.
Collapse
Affiliation(s)
- Martin Meschkat
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Electron Microscopy Core Unit, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Göttingen Graduate Center for Neurosciences, Biophysics, and Molecular Biosciences (GGNB), Göttingen, Germany.,DFG Research Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany.,Abberior Instruments GmbH, Göttingen, Germany
| | - Anna M Steyer
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Electron Microscopy Core Unit, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,DFG Research Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany.,Imaging Centre, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | - Marie-Theres Weil
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Electron Microscopy Core Unit, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,DFG Research Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany
| | - Kathrin Kusch
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany
| | - Olaf Jahn
- DFG Research Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany.,Proteomics Group, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Translational Neuroproteomics Group, Department of Psychiatry and Psychotherapy, University Medical Center Göttingen, Göttingen, Germany
| | - Lars Piepkorn
- Proteomics Group, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Translational Neuroproteomics Group, Department of Psychiatry and Psychotherapy, University Medical Center Göttingen, Göttingen, Germany
| | - Paola Agüi-Gonzalez
- Department of Neuro- and Sensory Physiology, University Medical Center Göttingen, Center for Biostructural Imaging of Neurodegeneration, Göttingen, Germany
| | - Nhu Thi Ngoc Phan
- Department of Neuro- and Sensory Physiology, University Medical Center Göttingen, Center for Biostructural Imaging of Neurodegeneration, Göttingen, Germany.,Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Torben Ruhwedel
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Electron Microscopy Core Unit, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Boguslawa Sadowski
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Electron Microscopy Core Unit, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,DFG Research Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany
| | - Silvio O Rizzoli
- DFG Research Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany.,Department of Neuro- and Sensory Physiology, University Medical Center Göttingen, Center for Biostructural Imaging of Neurodegeneration, Göttingen, Germany.,Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, Göttingen, Germany
| | - Hauke B Werner
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Hannelore Ehrenreich
- DFG Research Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany.,Clinical Neuroscience, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Klaus-Armin Nave
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,DFG Research Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany
| | - Wiebke Möbius
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany. .,Electron Microscopy Core Unit, Max Planck Institute of Experimental Medicine, Göttingen, Germany. .,DFG Research Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany. .,Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, Göttingen, Germany.
| |
Collapse
|
5
|
Montani L. Lipids in regulating oligodendrocyte structure and function. Semin Cell Dev Biol 2020; 112:114-122. [PMID: 32912639 DOI: 10.1016/j.semcdb.2020.07.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 07/17/2020] [Accepted: 07/29/2020] [Indexed: 12/15/2022]
Abstract
Oligodendrocytes enwrap central nervous system axons with myelin, a lipid enriched highly organized multi-layer membrane structure that allows for fast long-distance saltatory conduction of neuronal impulses. Myelin has an extremely high lipid content (∼80 % of its dry weight) and a peculiar lipid composition, with a 2:2:1 cholesterol:phospholipid:glycolipid ratio. Inherited neurodegenerative diseases of the lipids (caused by mutations in lipogenic enzymes) often present oligodendrocyte and/or myelin defects which contribute to the overall disease pathophysiology. These phenomena triggered an increasing number of studies over the functions lipid exert to shape and maintain myelin, and brought to the finding that lipids are more than only structural building blocks. They act as signaling molecules to drive proliferation and differentiation of oligodendrocyte progenitor cells, as well as proliferation of premyelinating oligodendrocytes, and their maturation into myelinating ones. Here, we summarize key findings in these areas, while presenting the main related human diseases. Despite many advances in the field, various questions remain open which we briefly discuss. This article is part of a special issue entitled "Role of Lipids in CNS Cell Physiology and Pathology".
Collapse
Affiliation(s)
- Laura Montani
- Institute of Molecular Health Sciences, Department of Biology, Swiss Federal Institute of Technology, ETH Zürich, Zürich, CH-8093, Switzerland.
| |
Collapse
|
6
|
Grassi S, Giussani P, Mauri L, Prioni S, Sonnino S, Prinetti A. Lipid rafts and neurodegeneration: structural and functional roles in physiologic aging and neurodegenerative diseases. J Lipid Res 2020; 61:636-654. [PMID: 31871065 PMCID: PMC7193971 DOI: 10.1194/jlr.tr119000427] [Citation(s) in RCA: 75] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 12/11/2019] [Indexed: 12/14/2022] Open
Abstract
Lipid rafts are small, dynamic membrane areas characterized by the clustering of selected membrane lipids as the result of the spontaneous separation of glycolipids, sphingolipids, and cholesterol in a liquid-ordered phase. The exact dynamics underlying phase separation of membrane lipids in the complex biological membranes are still not fully understood. Nevertheless, alterations in the membrane lipid composition affect the lateral organization of molecules belonging to lipid rafts. Neural lipid rafts are found in brain cells, including neurons, astrocytes, and microglia, and are characterized by a high enrichment of specific lipids depending on the cell type. These lipid rafts seem to organize and determine the function of multiprotein complexes involved in several aspects of signal transduction, thus regulating the homeostasis of the brain. The progressive decline of brain performance along with physiological aging is at least in part associated with alterations in the composition and structure of neural lipid rafts. In addition, neurodegenerative conditions, such as lysosomal storage disorders, multiple sclerosis, and Parkinson's, Huntington's, and Alzheimer's diseases, are frequently characterized by dysregulated lipid metabolism, which in turn affects the structure of lipid rafts. Several events underlying the pathogenesis of these diseases appear to depend on the altered composition of lipid rafts. Thus, the structure and function of lipid rafts play a central role in the pathogenesis of many common neurodegenerative diseases.jlr;61/5/636/F1F1f1.
Collapse
Affiliation(s)
- Sara Grassi
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Milan, Italy
| | - Paola Giussani
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Milan, Italy
| | - Laura Mauri
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Milan, Italy
| | - Simona Prioni
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Milan, Italy
| | - Sandro Sonnino
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Milan, Italy
| | - Alessandro Prinetti
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Milan, Italy. mailto:
| |
Collapse
|
7
|
Poitelon Y, Kopec AM, Belin S. Myelin Fat Facts: An Overview of Lipids and Fatty Acid Metabolism. Cells 2020; 9:cells9040812. [PMID: 32230947 PMCID: PMC7226731 DOI: 10.3390/cells9040812] [Citation(s) in RCA: 148] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 03/24/2020] [Accepted: 03/25/2020] [Indexed: 12/11/2022] Open
Abstract
Myelin is critical for the proper function of the nervous system and one of the most complex cell–cell interactions of the body. Myelination allows for the rapid conduction of action potentials along axonal fibers and provides physical and trophic support to neurons. Myelin contains a high content of lipids, and the formation of the myelin sheath requires high levels of fatty acid and lipid synthesis, together with uptake of extracellular fatty acids. Recent studies have further advanced our understanding of the metabolism and functions of myelin fatty acids and lipids. In this review, we present an overview of the basic biology of myelin lipids and recent insights on the regulation of fatty acid metabolism and functions in myelinating cells. In addition, this review may serve to provide a foundation for future research characterizing the role of fatty acids and lipids in myelin biology and metabolic disorders affecting the central and peripheral nervous system.
Collapse
|
8
|
Widder K, Harauz G, Hinderberger D. Myelin basic protein (MBP) charge variants show different sphingomyelin-mediated interactions with myelin-like lipid monolayers. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1862:183077. [PMID: 31805269 DOI: 10.1016/j.bbamem.2019.183077] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 08/13/2019] [Accepted: 09/16/2019] [Indexed: 12/12/2022]
Abstract
Multiple sclerosis (MS) is correlated with increased deimination of myelin basic protein (MBP) in the central nervous system. Here, the interaction of MBP C1 (charge: +19) and MBP C8 (charge: +13) with the major lipids of the cytoplasmic side of the oligodendrocyte membrane is analysed using monolayer adsorption experiments and epifluorescence microscopy. Our findings show that the electrostatic attraction between the positively charged proteins and negatively charged lipids in the myelin-like monolayers competes with the incorporation of MBP into regions directly bordering cholesterol-rich domains. The latter is favoured to avoid additional lipid condensation and reduction in fluidity of the phospholipid layer. We find that MBP C1 does not incorporate at the cholesterol-rich domains if sphingomyelin (SM) is absent from the lipid composition. In contrast, MBP C8 is still incorporated near cholesterol-enriched regions without SM. Thus, the highly charged C1 variant needs a specific interaction with SM, whereas for C8 the incorporation at the cholesterol-rich regions is ensured due to its reduced net positive charge. This phenomenon may be relevant for the correlation of higher amounts of MBP C8 in brains of adult MS patients and healthy children, in which the amount of SM is reduced compared to healthy adults.
Collapse
Affiliation(s)
- Katharina Widder
- Institut für Chemie, Martin-Luther-Universität Halle-Wittenberg, Von-Danckelmann-Platz 4, Halle (Saale) 06120, Germany
| | - George Harauz
- Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Road East, Guelph, Ontario N1G 2W1, Canada
| | - Dariush Hinderberger
- Institut für Chemie, Martin-Luther-Universität Halle-Wittenberg, Von-Danckelmann-Platz 4, Halle (Saale) 06120, Germany.
| |
Collapse
|
9
|
Guimarães AJ, de Cerqueira MD, Zamith-Miranda D, Lopez PH, Rodrigues ML, Pontes B, Viana NB, DeLeon-Rodriguez CM, Rossi DCP, Casadevall A, Gomes AMO, Martinez LR, Schnaar RL, Nosanchuk JD, Nimrichter L. Host membrane glycosphingolipids and lipid microdomains facilitate Histoplasma capsulatum internalisation by macrophages. Cell Microbiol 2018; 21:e12976. [PMID: 30427108 DOI: 10.1111/cmi.12976] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 09/03/2018] [Accepted: 09/17/2018] [Indexed: 12/17/2022]
Abstract
Recognition and internalisation of intracellular pathogens by host cells is a multifactorial process, involving both stable and transient interactions. The plasticity of the host cell plasma membrane is fundamental in this infectious process. Here, the participation of macrophage lipid microdomains during adhesion and internalisation of the fungal pathogen Histoplasma capsulatum (Hc) was investigated. An increase in membrane lateral organisation, which is a characteristic of lipid microdomains, was observed during the first steps of Hc-macrophage interaction. Cholesterol enrichment in macrophage membranes around Hc contact regions and reduced levels of Hc-macrophage association after cholesterol removal also suggested the participation of lipid microdomains during Hc-macrophage interaction. Using optical tweezers to study cell-to-cell interactions, we showed that cholesterol depletion increased the time required for Hc adhesion. Additionally, fungal internalisation was significantly reduced under these conditions. Moreover, macrophages treated with the ceramide-glucosyltransferase inhibitor (P4r) and macrophages with altered ganglioside synthesis (from B4galnt1-/- mice) showed a deficient ability to interact with Hc. Coincubation of oligo-GM1 and treatment with Cholera toxin Subunit B, which recognises the ganglioside GM1, also reduced Hc association. Although purified GM1 did not alter Hc binding, treatment with P4 significantly increased the time required for Hc binding to macrophages. The content of CD18 was displaced from lipid microdomains in B4galnt1-/- macrophages. In addition, macrophages with reduced CD18 expression (CD18low ) were associated with Hc at levels similar to wild-type cells. Finally, CD11b and CD18 colocalised with GM1 during Hc-macrophage interaction. Our results indicate that lipid rafts and particularly complex gangliosides that reside in lipid rafts stabilise Hc-macrophage adhesion and mediate efficient internalisation during histoplasmosis.
Collapse
Affiliation(s)
- Allan J Guimarães
- Department of Microbiology and Parasitology, Biomedical Institute, Fluminense Federal University, Rio de Janeiro, Brazil.,Departments of Medicine (Division of Infectious Diseases) and Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York
| | - Mariana Duarte de Cerqueira
- Department of General Microbiology, Microbiology Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Daniel Zamith-Miranda
- Department of General Microbiology, Microbiology Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Pablo H Lopez
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Marcio L Rodrigues
- Department of General Microbiology, Microbiology Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.,Instituto Carlos Chagas, Fundação Oswaldo Cruz (Fiocruz), Curitiba, Brazil
| | - Bruno Pontes
- LPO-COPEA, Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Nathan B Viana
- LPO-COPEA, Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.,LPO-COPEA, Institute of Physics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Carlos M DeLeon-Rodriguez
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Diego Conrado Pereira Rossi
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Arturo Casadevall
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Andre M O Gomes
- Program of Structural Biology, Institute of Medical Biochemistry Leopoldo de Meis and National Institute of Science and Technology of Structural Biology and Bioimaging, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Luis R Martinez
- Biological Sciences, The University of Texas at El Paso, El Paso, Texas
| | - Ronald L Schnaar
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Joshua D Nosanchuk
- Departments of Medicine (Division of Infectious Diseases) and Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York
| | - Leonardo Nimrichter
- Department of General Microbiology, Microbiology Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| |
Collapse
|
10
|
Can the Fact That Myelin Proteins Are Old and Break down Explain the Origin of Multiple Sclerosis in Some People? J Clin Med 2018; 7:jcm7090281. [PMID: 30223497 PMCID: PMC6162792 DOI: 10.3390/jcm7090281] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 09/11/2018] [Accepted: 09/12/2018] [Indexed: 01/01/2023] Open
Abstract
Recent discoveries may change the way that multiple sclerosis (MS) is viewed, particularly with regard to the reasons for the untoward immune response. The fact that myelin proteins are long-lived, and that by the time we are adults, they are extensively degraded, alters our perspective on the reasons for the onset of autoimmunity and the origin of MS. For example, myelin basic protein (MBP) from every human brain past the age of 20 years, is so greatly modified, that it is effectively a different protein from the one that was laid down in childhood. Since only a subset of people with such degraded MBP develop MS, a focus on understanding the mechanism of immune responses to central nervous system (CNS) antigens and cerebral immune tolerance appear to be worthwhile avenues to explore. In accord with this, it will be productive to examine why all people, whose brains contain large quantities of a "foreign antigen", do not develop MS. Importantly for the potential causation of MS, MBP from MS patients breaks down differently from the MBP in aged controls. If the novel structures formed in these MS-specific regions are particularly antigenic, it could help explain the origin of MS. If verified, these findings could provide an avenue for the rational synthesis of drugs to prevent and treat MS.
Collapse
|
11
|
Tiwari S, Lapierre J, Ojha CR, Martins K, Parira T, Dutta RK, Caobi A, Garbinski L, Ceyhan Y, Esteban-Lopez M, El-Hage N. Signaling pathways and therapeutic perspectives related to environmental factors associated with multiple sclerosis. J Neurosci Res 2018; 96:1831-1846. [PMID: 30204260 PMCID: PMC7167107 DOI: 10.1002/jnr.24322] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 08/09/2018] [Accepted: 08/13/2018] [Indexed: 12/16/2022]
Abstract
Multiple sclerosis (MS) is an immune-mediated demyelinating disorder of unknown etiology. Both genetic-susceptibility and environment exposures, including vitamin D deficiency, Epstein-Barr viral and Herpesvirus (HHV-6) infections are strongly implicated in the activation of T cells and MS-pathogenesis. Despite precise knowledge of how these factors could be operating alone or in combination to facilitate and aggravate the disease progression, it is clear that prolonged induction of inflammatory molecules and recruitment of other immune cells by the activated T cells results in demyelination and axonal damage. It is imperative to understand the risk factors associated with MS progression and how these factors contribute to disease pathology. Understanding of the underlying mechanisms of what factors triggers activation of T cells to attack myelin antigen are important to strategize therapeutics and therapies against MS. Current review provides a detailed literature to understand the role of both pathogenic and non-pathogenic factors on the impact of MS.
Collapse
Affiliation(s)
- Sneham Tiwari
- Departments of Immunology, Herbert Wertheim College of Medicine, Florida International University, Miami, Florida
| | - Jessica Lapierre
- Departments of Immunology, Herbert Wertheim College of Medicine, Florida International University, Miami, Florida
| | - Chet Raj Ojha
- Departments of Immunology, Herbert Wertheim College of Medicine, Florida International University, Miami, Florida
| | - Kyle Martins
- Human and Molecular Genetics, Herbert Wertheim College of Medicine, Florida International University, Miami, Florida
| | - Tiyash Parira
- Departments of Immunology, Herbert Wertheim College of Medicine, Florida International University, Miami, Florida
| | - Rajib Kumar Dutta
- Departments of Immunology, Herbert Wertheim College of Medicine, Florida International University, Miami, Florida
| | - Allen Caobi
- Departments of Immunology, Herbert Wertheim College of Medicine, Florida International University, Miami, Florida
| | - Luis Garbinski
- Cell Biology and Pharmacology, Herbert Wertheim College of Medicine, Florida International University, Miami, Florida
| | - Yasemin Ceyhan
- Human and Molecular Genetics, Herbert Wertheim College of Medicine, Florida International University, Miami, Florida
| | - Maria Esteban-Lopez
- Human and Molecular Genetics, Herbert Wertheim College of Medicine, Florida International University, Miami, Florida
| | - Nazira El-Hage
- Departments of Immunology, Herbert Wertheim College of Medicine, Florida International University, Miami, Florida
| |
Collapse
|
12
|
Adebiyi OE, Olopade JO, Olayemi FO. Sodium metavanadate induced cognitive decline, behavioral impairments, oxidative stress and down regulation of myelin basic protein in mice hippocampus: Ameliorative roles of β-spinasterol, and stigmasterol. Brain Behav 2018; 8:e01014. [PMID: 29856129 PMCID: PMC6043703 DOI: 10.1002/brb3.1014] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2017] [Revised: 04/10/2018] [Accepted: 04/17/2018] [Indexed: 12/29/2022] Open
Abstract
INTRODUCTION Exposures to toxic levels of vanadium and soluble vanadium compounds cause behavioral impairments and neurodegeneration via free radical production. Consequently, natural antioxidant sources have been explored for effective and cheap remedy following toxicity. Grewia carpinifolia has been shown to improve behavioral impairments in vanadium-induced neurotoxicity, however, the active compounds implicated remains unknown. Therefore, this study was conducted to investigate ameliorative effects of bioactive compounds from G. carpinifolia on memory and behavioral impairments in vanadium-induced neurotoxicity. METHODS Sixty BALB/c mice were equally divided into five groups (A-E). A (control); administered distilled water, B (standard); administered α-tocopherol (500 mg/kg) every 72 hr orally with daily dose of sodium metavanadate (3 mg/kg) intraperitoneally, test groups C, and D; received single oral dose of 100 μg β-spinasterol or stigmasterol (bioactive compounds from G. carpinifolia), respectively, along with sodium metavanadate and the model group E, received sodium metavanadate only for seven consecutive days. Memory, locomotion and muscular strength were accessed using Morris water maze, Open field and hanging wire tests. In vivo antioxidant and neuroprotective activities were evaluated by measuring catalase, superoxide dismutase, MDA, H2 O2 , and myelin basic protein (MBP) expression in the hippocampus. RESULTS In Morris water maze, stigmasterol significantly (p ≤ 0.05) decreased escape latency and increased swimming time in target quadrant (28.01 ± 0.02; 98.24 ± 17.38 s), respectively, better than α-tocopherol (52.43 ± 13.25; 80.32 ± 15.21) and β-spinasterol (42.09 ± 14.27; 70.91 ± 19.24) in sodium metavanadate-induced memory loss (112.31 ± 9.35; 42.35 ± 11.05). β-Spinasterol and stigmasterol significantly increased exploration and latency in open field and hanging wire tests respectively. Stigmasterol also increased activities of antioxidant enzymes, decreased oxidative stress markers and lipid peroxidation in mice hippocampal homogenates, and increased MBP expression. CONCLUSIONS The findings of this study indicate a potential for stigmasterol, a bioactive compound from G. carpinifolia in improving cognitive decline, motor coordination, and ameliorating oxidative stress in vanadium-induced neurotoxicity.
Collapse
|
13
|
Olsen ASB, Færgeman NJ. Sphingolipids: membrane microdomains in brain development, function and neurological diseases. Open Biol 2018; 7:rsob.170069. [PMID: 28566300 PMCID: PMC5451547 DOI: 10.1098/rsob.170069] [Citation(s) in RCA: 201] [Impact Index Per Article: 33.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 04/30/2017] [Indexed: 12/11/2022] Open
Abstract
Sphingolipids are highly enriched in the nervous system where they are pivotal constituents of the plasma membranes and are important for proper brain development and functions. Sphingolipids are not merely structural elements, but are also recognized as regulators of cellular events by their ability to form microdomains in the plasma membrane. The significance of such compartmentalization spans broadly from being involved in differentiation of neurons and synaptic transmission to neuronal–glial interactions and myelin stability. Thus, perturbations of the sphingolipid metabolism can lead to rearrangements in the plasma membrane, which has been linked to the development of various neurological diseases. Studying microdomains and their functions has for a long time been synonymous with studying the role of cholesterol. However, it is becoming increasingly clear that microdomains are very heterogeneous, which among others can be ascribed to the vast number of sphingolipids. In this review, we discuss the importance of microdomains with emphasis on sphingolipids in brain development and function as well as how disruption of the sphingolipid metabolism (and hence microdomains) contributes to the pathogenesis of several neurological diseases.
Collapse
Affiliation(s)
- Anne S B Olsen
- Villum Center for Bioanalytical Sciences, Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense M, Denmark
| | - Nils J Færgeman
- Villum Center for Bioanalytical Sciences, Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense M, Denmark
| |
Collapse
|
14
|
Harauz G. And Yet it is Modified-Holding a Candle to the Dark Matter of White Matter. Proteomics 2017; 17. [PMID: 28851044 DOI: 10.1002/pmic.201700299] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Indexed: 11/08/2022]
Abstract
The multilamellar membrane myelin sheath of the CNS, that enwraps axons to facilitate saltatory conduction in higher vertebrates, is held together by myelin basic protein (MBP). Yet this generalization masks how enigmatic MBP is, much like cosmological "dark matter." First, the casual use of the singular form for "protein" distracts that there are multiple, developmentally regulated "classic" splice isoforms ranging from 14 to 21.5 kDa, each with extensive PTMs. Second, the static image of MBP adhering two cytoplasmic leaflets of the oligodendrocyte membrane together in close apposition, suggests it to be inaccessible to modifying enzymes. And yet it is modified (to paraphrase Galileo's phrase on the earth's motion). In this issue of Proteomics, Sarg et al. apply an integrated CE-MS approach to investigate the PTMs of 18.5 kDa MBP from mouse brains of different ages. They identify new sites and types of modification, as well as confirming previously known PTMs. Innovative tools for unraveling the intricacies of the myelin basic proteome and how it organizes CNS myelin (much like basic histones organize chromatin), will help us understand white matter development and plasticity in health, during ageing, and in demyelinating diseases such as multiple sclerosis.
Collapse
Affiliation(s)
- George Harauz
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Canada
| |
Collapse
|
15
|
Myelin structure in unfixed, single nerve fibers: Scanning X-ray microdiffraction with a beam size of 200nm. J Struct Biol 2017; 200:229-243. [PMID: 28698109 DOI: 10.1016/j.jsb.2017.07.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Revised: 06/27/2017] [Accepted: 07/07/2017] [Indexed: 11/21/2022]
Abstract
Previous raster-scanning with a 1μm X-ray beam of individual, myelinated fibers from glutaraldehyde-fixed rat sciatic nerve revealed a spatially-dependent variation in the diffraction patterns from single fibers. Analysis indicated differences in the myelin periodicity, membrane separations, distribution of proteins, and orientation of membrane lamellae. As chemical fixation is known to produce structural artifacts, we sought to determine in the current study whether the structural heterogeneity is intrinsic to unfixed myelin. Using a 200nm-beam that was about five-fold smaller than before, we raster-scanned individual myelinated fibers from both the peripheral (PNS; mouse and rat sciatic nerves) and central (CNS; rat corpus callosum) nervous systems. As expected, the membrane stacking in the internodal region was nearly parallel to the fiber axis and in the paranodal region it was perpendicular to the axis. A myelin lattice was also frequently observed when the incident beam was injected en face to the sheath. Myelin periodicity and diffracted intensity varied with axial position along the fiber, as did the calculated membrane profiles. Raster-scanning with an X-ray beam at sub-micron resolution revealed for the first time that the individual myelin sheaths in unfixed nerve are heterogeneous in both membrane structure and packing.
Collapse
|
16
|
Ozgen H, Baron W, Hoekstra D, Kahya N. Oligodendroglial membrane dynamics in relation to myelin biogenesis. Cell Mol Life Sci 2016; 73:3291-310. [PMID: 27141942 PMCID: PMC4967101 DOI: 10.1007/s00018-016-2228-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 04/14/2016] [Indexed: 12/12/2022]
Abstract
In the central nervous system, oligodendrocytes synthesize a specialized membrane, the myelin membrane, which enwraps the axons in a multilamellar fashion to provide fast action potential conduction and to ensure axonal integrity. When compared to other membranes, the composition of myelin membranes is unique with its relatively high lipid to protein ratio. Their biogenesis is quite complex and requires a tight regulation of sequential events, which are deregulated in demyelinating diseases such as multiple sclerosis. To devise strategies for remedying such defects, it is crucial to understand molecular mechanisms that underlie myelin assembly and dynamics, including the ability of specific lipids to organize proteins and/or mediate protein-protein interactions in healthy versus diseased myelin membranes. The tight regulation of myelin membrane formation has been widely investigated with classical biochemical and cell biological techniques, both in vitro and in vivo. However, our knowledge about myelin membrane dynamics, such as membrane fluidity in conjunction with the movement/diffusion of proteins and lipids in the membrane and the specificity and role of distinct lipid-protein and protein-protein interactions, is limited. Here, we provide an overview of recent findings about the myelin structure in terms of myelin lipids, proteins and membrane microdomains. To give insight into myelin membrane dynamics, we will particularly highlight the application of model membranes and advanced biophysical techniques, i.e., approaches which clearly provide an added value to insight obtained by classical biochemical techniques.
Collapse
Affiliation(s)
- Hande Ozgen
- Department of Cell Biology, University Medical Center Groningen, University of Groningen, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands
| | - Wia Baron
- Department of Cell Biology, University Medical Center Groningen, University of Groningen, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands.
| | - Dick Hoekstra
- Department of Cell Biology, University Medical Center Groningen, University of Groningen, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands
| | - Nicoletta Kahya
- Department of Cell Biology, University Medical Center Groningen, University of Groningen, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands
| |
Collapse
|
17
|
Appadu A, Jelokhani-Niaraki M, DeBruin L. Conformational Changes and Association of Membrane-Interacting Peptides in Myelin Membrane Models: A Case of the C-Terminal Peptide of Proteolipid Protein and the Antimicrobial Peptide Melittin. J Phys Chem B 2015; 119:14821-30. [DOI: 10.1021/acs.jpcb.5b07375] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ashtina Appadu
- Department
of Chemistry and
Biochemistry, Wilfrid Laurier University, 75 University Ave. W., Waterloo, Ontario, Canada N2L 3C5
| | - Masoud Jelokhani-Niaraki
- Department
of Chemistry and
Biochemistry, Wilfrid Laurier University, 75 University Ave. W., Waterloo, Ontario, Canada N2L 3C5
| | - Lillian DeBruin
- Department
of Chemistry and
Biochemistry, Wilfrid Laurier University, 75 University Ave. W., Waterloo, Ontario, Canada N2L 3C5
| |
Collapse
|
18
|
Grassi S, Prioni S, Cabitta L, Aureli M, Sonnino S, Prinetti A. The Role of 3-O-Sulfogalactosylceramide, Sulfatide, in the Lateral Organization of Myelin Membrane. Neurochem Res 2015; 41:130-43. [DOI: 10.1007/s11064-015-1747-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Revised: 10/22/2015] [Accepted: 10/24/2015] [Indexed: 12/12/2022]
|
19
|
MyelStones: the executive roles of myelin basic protein in myelin assembly and destabilization in multiple sclerosis. Biochem J 2015; 472:17-32. [DOI: 10.1042/bj20150710] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The classic isoforms of myelin basic protein (MBP, 14–21.5 kDa) are essential to formation of the multilamellar myelin sheath of the mammalian central nervous system (CNS). The predominant 18.5-kDa isoform links together the cytosolic surfaces of oligodendrocytes, but additionally participates in cytoskeletal turnover and membrane extension, Fyn-mediated signalling pathways, sequestration of phosphoinositides and maintenance of calcium homoeostasis. All MBP isoforms are intrinsically disordered proteins (IDPs) that interact via molecular recognition fragments (MoRFs), which thereby undergo local disorder-to-order transitions. Their conformations and associations are modulated by environment and by a dynamic barcode of post-translational modifications, particularly phosphorylation by mitogen-activated and other protein kinases and deimination [a hallmark of demyelination in multiple sclerosis (MS)]. The MBPs are thus to myelin what basic histones are to chromatin. Originally thought to be merely structural proteins forming an inert spool, histones are now known to be dynamic entities involved in epigenetic regulation and diseases such as cancer. Analogously, the MBPs are not mere adhesives of compact myelin, but active participants in oligodendrocyte proliferation and in membrane process extension and stabilization during myelinogenesis. A central segment of these proteins is pivotal in membrane-anchoring and SH3 domain (Src homology 3) interaction. We discuss in the present review advances in our understanding of conformational conversions of this classic basic protein upon membrane association, including new thermodynamic analyses of transitions into different structural ensembles and how a shift in the pattern of its post-translational modifications is associated with the pathogenesis and potentially onset of demyelination in MS.
Collapse
|
20
|
Frid K, Einstein O, Friedman-Levi Y, Binyamin O, Ben-Hur T, Gabizon R. Aggregation of MBP in chronic demyelination. Ann Clin Transl Neurol 2015; 2:711-21. [PMID: 26273684 PMCID: PMC4531054 DOI: 10.1002/acn3.207] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 03/26/2015] [Indexed: 12/14/2022] Open
Abstract
Objectives Misfolding of key disease proteins to an insoluble state is associated with most neurodegenerative conditions, such as prion, Parkinson, and Alzheimer’s diseases. In this work, and by studying animal models of multiple sclerosis, we asked whether this is also the case for myelin basic protein (MBP) in the late and neurodegenerative phases of demyelinating diseases. Methods To this effect, we tested whether MBP, an essential myelin component, present prion-like properties in animal models of MS, as is the case for Cuprizone-induced chronic demyelination or chronic phases of Experimental Autoimmune Encephalomyelitis (EAE). Results We show here that while total levels of MBP were not reduced following extensive demyelination, part of these molecules accumulated thereafter as aggregates inside oligodendrocytes or around neuronal cells. In chronic EAE, MBP precipitated concomitantly with Tau, a marker of diverse neurodegenerative conditions, including MS. Most important, analysis of fractions from Triton X-100 floatation gradients suggest that the lipid composition of brain membranes in chronic EAE differs significantly from that of naïve mice, an effect which may relate to oxidative insults and subsequently prevent the appropriate insertion and compaction of new MBP in the myelin sheath, thereby causing its misfolding and aggregation. Interpretation Prion-like aggregation of MBP following chronic demyelination may result from an aberrant lipid composition accompanying this pathological status. Such aggregation of MBP may contribute to neuronal damage that occurs in the progressive phase of MS.
Collapse
Affiliation(s)
- Kati Frid
- Department of Neurology, The Agnes Ginges Center for Human Neurogenetics, Hadassah University Hospital Jerusalem, 91120, Israel
| | - Ofira Einstein
- Department of Neurology, The Agnes Ginges Center for Human Neurogenetics, Hadassah University Hospital Jerusalem, 91120, Israel
| | - Yael Friedman-Levi
- Department of Neurology, The Agnes Ginges Center for Human Neurogenetics, Hadassah University Hospital Jerusalem, 91120, Israel
| | - Orli Binyamin
- Department of Neurology, The Agnes Ginges Center for Human Neurogenetics, Hadassah University Hospital Jerusalem, 91120, Israel
| | - Tamir Ben-Hur
- Department of Neurology, The Agnes Ginges Center for Human Neurogenetics, Hadassah University Hospital Jerusalem, 91120, Israel
| | - Ruth Gabizon
- Department of Neurology, The Agnes Ginges Center for Human Neurogenetics, Hadassah University Hospital Jerusalem, 91120, Israel
| |
Collapse
|
21
|
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.
Collapse
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.
| |
Collapse
|
22
|
Yamamoto K, Miyazaki K, Higashi S. Pericellular proteolysis by matrix metalloproteinase-7 is differentially modulated by cholesterol sulfate, sulfatide, and cardiolipin. FEBS J 2014; 281:3346-56. [PMID: 24903600 DOI: 10.1111/febs.12865] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Revised: 05/26/2014] [Accepted: 05/28/2014] [Indexed: 11/30/2022]
Abstract
Matrix metalloproteinase (MMP)-7 binds to cell surface cholesterol sulfate (CS) and acts as a membrane-associated protease. We have previously found that CS modulates the substrate preference of MMP-7, thereby regulating its pericellular proteolytic action. MMP-7 potentially associates with the cell surface via sulfatide (SM4) and cardiolipin (CL) when they are overexpressed on the cell surface. Here, we investigated the molecular interaction between these acidic lipids and MMP-7 or its substrates, and their effects on the activity of MMP-7. Studies using MMP-7 variants with low CS-binding ability suggested that these lipids interact with a similar site on MMP-7. The hydroxamate-based MMP inhibitor TAPI-1 markedly reduced the affinity of MMP-7 for CS and CL, whereas that for SM4 was not affected by TAPI-1. These three acidic lipids also had different effects on the hydrolytic activity of MMP-7 towards a small peptide substrate: SM4, CL and CS reduced the activity to 80%, 92%, and 20%, respectively. Nevertheless, SM4 and CS similarly accelerated the MMP-7-catalyzed degradation of fibronectin and laminin-332, whereas CL did not. The increased proteolysis of substrate was observed only when both substrate and enzyme had affinity for the lipid, suggesting that the lipids probably bring the reactants into closer proximity. Furthermore, MMP-7 bound to cell surface SM4 or CS cleaved specific cell surface proteins and released similar fragments, whereas the cleavage was not stimulated by cell surface CL-bound MMP-7. This study provides a novel mechanism by which acidic lipids differentially regulate pericellular proteolysis by MMP-7 through allosteric alteration of the substrate-binding site and their inherent affinities for MMP-7 substrates.
Collapse
Affiliation(s)
- Kazuhiro Yamamoto
- Graduate School of Nanobioscience, Yokohama City University, Japan; Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, Kennedy Institute of Rheumatology, University of Oxford, UK
| | | | | |
Collapse
|
23
|
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.
Collapse
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)
| |
Collapse
|
24
|
Inouye H, Liu J, Makowski L, Palmisano M, Burghammer M, Riekel C, Kirschner DA. Myelin organization in the nodal, paranodal, and juxtaparanodal regions revealed by scanning x-ray microdiffraction. PLoS One 2014; 9:e100592. [PMID: 24984037 PMCID: PMC4077703 DOI: 10.1371/journal.pone.0100592] [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: 04/03/2014] [Accepted: 05/09/2014] [Indexed: 12/03/2022] Open
Abstract
X-ray diffraction has provided extensive information about the arrangement of lipids and proteins in multilamellar myelin. This information has been limited to the abundant inter-nodal regions of the sheath because these regions dominate the scattering when x-ray beams of 100 µm diameter or more are used. Here, we used a 1 µm beam, raster-scanned across a single nerve fiber, to obtain detailed information about the molecular architecture in the nodal, paranodal, and juxtaparanodal regions. Orientation of the lamellar membrane stacks and membrane periodicity varied spatially. In the juxtaparanode-internode, 198–202 Å-period membrane arrays oriented normal to the nerve fiber axis predominated, whereas in the paranode-node, 205–208 Å-period arrays oriented along the fiber direction predominated. In parts of the sheath distal to the node, multiple sets of lamellar reflections were observed at angles to one another, suggesting that the myelin multilayers are deformed at the Schmidt-Lanterman incisures. The calculated electron density of myelin in the different regions exhibited membrane bilayer profiles with varied electron densities at the polar head groups, likely due to different amounts of major myelin proteins (P0 glycoprotein and myelin basic protein). Scattering from the center of the nerve fibers, where the x-rays are incident en face (perpendicular) to the membrane planes, provided information about the lateral distribution of protein. By underscoring the heterogeneity of membrane packing, microdiffraction analysis suggests a powerful new strategy for understanding the underlying molecular foundation of a broad spectrum of myelinopathies dependent on local specializations of myelin structure in both the PNS and CNS.
Collapse
Affiliation(s)
- Hideyo Inouye
- Department of Electrical and Computer Engineering, Northeastern University, Boston, Massachusetts, United States of America
| | - Jiliang Liu
- Department of Electrical and Computer Engineering, Northeastern University, Boston, Massachusetts, United States of America
| | - Lee Makowski
- Department of Electrical and Computer Engineering, Northeastern University, Boston, Massachusetts, United States of America
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts, United States of America
| | - Marilena Palmisano
- Division of Cell Biology & Genetics, Università Vita-Salute San Raffaele, Milano, Italy
| | | | | | - Daniel A. Kirschner
- Biology Department, Boston College, Chestnut Hill, Massachusetts, United States of America
- * E-mail:
| |
Collapse
|
25
|
Boggs JM, Homchaudhuri L, Ranagaraj G, Liu Y, Smith GST, Harauz G. Interaction of myelin basic protein with cytoskeletal and signaling proteins in cultured primary oligodendrocytes and N19 oligodendroglial cells. BMC Res Notes 2014; 7:387. [PMID: 24956930 PMCID: PMC4078013 DOI: 10.1186/1756-0500-7-387] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Accepted: 06/18/2014] [Indexed: 12/13/2022] Open
Abstract
Background The classic myelin basic protein (MBP) isoforms are intrinsically-disordered proteins of 14–21.5 kDa in size arising from the Golli (Gene in the Oligodendrocyte Lineage) gene complex, and are responsible for formation of the multilayered myelin sheath in the central nervous system. The predominant membrane-associated isoform of MBP is not simply a structural component of compact myelin but is highly post-translationally modified and multi-functional, having interactions with numerous proteins such as Ca2+-calmodulin, and with actin, tubulin, and proteins with SH3-domains, which it can tether to a lipid membrane in vitro. It co-localizes with such proteins in primary oligodendrocytes (OLGs) and in early developmental N19-OLGs transfected with fluorescently-tagged MBP. Results To provide further evidence for MBP associations with these proteins in vivo, we show here that MBP isoforms are co-immunoprecipitated from detergent extracts of primary OLGs together with actin, tubulin, zonula occludens 1 (ZO-1), cortactin, and Fyn kinase. We also carry out live-cell imaging of N19-OLGs co-transfected with fluorescent MBP and actin, and show that when actin filaments re-assemble after recovery from cytochalasin D treatment, MBP and actin are rapidly enriched and co-localized at certain sites at the plasma membrane and in newly-formed membrane ruffles. The MBP and actin distributions change similarly with time, suggesting a specific and dynamic association. Conclusions These results provide more direct evidence for association of the predominant 18.5-kDa MBP isoform with these proteins in primary OLGs and in live cells than previously could be inferred from co-localization observations. This study supports further a role for classic MBP isoforms in protein-protein interactions during membrane and cytoskeletal extension and remodeling in OLGs.
Collapse
Affiliation(s)
- Joan M Boggs
- Molecular Structure and Function Program, Research Institute, Hospital for Sick Children, 686 Bay St, Toronto, ON M5G 0A4, Canada.
| | | | | | | | | | | |
Collapse
|
26
|
Bakhti M, Aggarwal S, Simons M. Myelin architecture: zippering membranes tightly together. Cell Mol Life Sci 2014; 71:1265-77. [PMID: 24165921 PMCID: PMC11113231 DOI: 10.1007/s00018-013-1492-0] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2013] [Revised: 09/11/2013] [Accepted: 10/07/2013] [Indexed: 12/12/2022]
Abstract
Rapid nerve conduction requires the coating of axons by a tightly packed multilayered myelin membrane. In the central nervous system, myelin is formed from cellular processes that extend from oligodendrocytes and wrap in a spiral fashion around an axon, resulting in the close apposition of adjacent myelin membrane bilayers. In this review, we discuss the physical principles underlying the zippering of the plasma membrane of oligodendrocytes at the cytoplasmic and extracellular leaflet. We propose that the interaction of the myelin basic protein with the cytoplasmic leaflet of the myelin bilayer triggers its polymerization into a fibrous network that drives membrane zippering and protein extrusion. In contrast, the adhesion of the extracellular surfaces of myelin requires the down-regulation of repulsive components of the glycocalyx, in order to uncover weak and unspecific attractive forces that bring the extracellular surfaces into close contact. Unveiling the mechanisms of myelin membrane assembly at the cytoplasmic and extracelluar sites may help to understand how the myelin bilayers are disrupted and destabilized in the different demyelinating diseases.
Collapse
Affiliation(s)
- Mostafa Bakhti
- Max-Planck-Institute of Experimental Medicine, Hermann-Rein-Str. 3, Göttingen, Germany
- Department of Neurology, University of Göttingen, Robert-Koch-Str. 40, Göttingen, Germany
- Present Address: Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, Neuherberg, Germany
| | - Shweta Aggarwal
- Max-Planck-Institute of Experimental Medicine, Hermann-Rein-Str. 3, Göttingen, Germany
- Department of Neurology, University of Göttingen, Robert-Koch-Str. 40, Göttingen, Germany
| | - Mikael Simons
- Max-Planck-Institute of Experimental Medicine, Hermann-Rein-Str. 3, Göttingen, Germany
- Department of Neurology, University of Göttingen, Robert-Koch-Str. 40, Göttingen, Germany
| |
Collapse
|
27
|
Zhao L, Guo Y, Ji X, Zhang M. The neuroprotective effect of picroside II via regulating the expression of myelin basic protein after cerebral ischemia injury in rats. BMC Neurosci 2014; 15:25. [PMID: 24524292 PMCID: PMC3926676 DOI: 10.1186/1471-2202-15-25] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Accepted: 02/11/2014] [Indexed: 12/17/2022] Open
Abstract
Background To explore the neuroprotective effect and optimize the therapeutic dose and time window of picroside II by orthogonal test and the expression of myelin basic protein (MBP) in cerebral ischemic injury in rats. Bilateral common carotid artery occlusion (BCCAO) was used to establish forebrain ischemia models. The successful rat models were grouped according to orthogonal experimental design and injected picroside II intraperitoneally at different ischemic time with different doses. Myelin sheath fast green staining(FGS) and transmission electron microscopy (TEM) were used to observe nerve fiber myelin; the expression of MBP was tested qualitatively and quantitatively by immunohistochemical assay (IHC) and Western blot (WB); Reverse transcription polymerase chain reaction (RT-PCR) was used to detect the transcription level of MBP mRNA. Results The protective effect of picroside II was presented by increasing the expression of MBP and decreasing demyelination after cerebral ischemic injury. The best therapeutic time window and dose was (1) ischemia 2.0 h with picroside II 10 mg/kg body weight according to the results of FGS, IHC and WB; (2) ischemia 1.5 h with picroside II 20 mg/kg according to the analysis of RT-PCR. Conclusion Given the principle of the longest time window and the lowest therapeutic dose, the optimized therapeutic dose and time window should be injecting picroside II intraperitoneally with 10-20 mg/kg body weight at ischemia 1.5-2.0 h in cerebral ischemic injury.
Collapse
Affiliation(s)
| | - Yunliang Guo
- Institute of Cerebrovascular Diseases, Affiliated Hospital of Qingdao University, Qingdao, Shandong 266003, China.
| | | | | |
Collapse
|
28
|
Uruse M, Yamamoto M, Sugawa M, Matsuura K, Sato Y, Seiwa C, Watanabe K, Aiso S, Asou H. Phase separation of myelin sheath in Triton X-114 solution: predominant localization of the 21.5-kDa isoform of myelin basic protein in the lipid raft-associated domain. J Biochem 2014; 155:265-71. [PMID: 24459152 DOI: 10.1093/jb/mvu005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Myelin basic protein (MBP) isoforms in the myelin sheath are known to have distinct intracellular expression patterns, which are profoundly related to functional specificity. Determining the differential localization of MBP isoforms is therefore important for understanding their pathophysiological roles. In this study, we have developed a new method for phase separation of myelin. The non-ionic detergent Triton X-114 is used to solubilize myelin sheath which then undergoes phase separation to yield four fractions. The lipid raft-associated proteins and lipids in each fraction were analysed by immunoblotting and lipid analysis, respectively. The present method gives two lipid raft-enriched fractions, one of them was found to contain only lipid raft-associated galactocerebroside and cholesterol as the major lipids. The 21.5-kDa MBP isoforms (21.5 MBP), both unphosphorylated and phosphorylated, were exclusively contained in this fraction. Phosphorylated 21.5 MBP (21.5 pMBP) has been shown to specifically disappear from demyelinated loci. The present analytical method clearly indicated that disappearance of 21.5 pMBP corresponded to demyelination and its reappearance corresponded to prevention of demyelination. Demyelination was also associated with aging and was prevented by the myelin-protecting herbal medicine, Chinpi, a type of dried citrus peel.
Collapse
Affiliation(s)
- Michihiro Uruse
- Center for Kampo Medicine, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582, Japan; Tsumura Research Laboratories, Tsumura & Co., Yoshiwara 3586, Ami-machi, Inashiki-gun, Ibaraki 300-1192, Japan; and Department of Anatomy, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|
29
|
Fang F, Zhang H, Zhang Y, Xu H, Huang Q, Adilijiang A, Wang J, Zhang Z, Zhang D, Tan Q, He J, Kong L, Liu Y, Li XM. Antipsychotics promote the differentiation of oligodendrocyte progenitor cells by regulating oligodendrocyte lineage transcription factors 1 and 2. Life Sci 2013; 93:429-34. [DOI: 10.1016/j.lfs.2013.08.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2012] [Revised: 07/24/2013] [Accepted: 08/09/2013] [Indexed: 01/06/2023]
|
30
|
Vassall KA, Bessonov K, De Avila M, Polverini E, Harauz G. The effects of threonine phosphorylation on the stability and dynamics of the central molecular switch region of 18.5-kDa myelin basic protein. PLoS One 2013; 8:e68175. [PMID: 23861868 PMCID: PMC3702573 DOI: 10.1371/journal.pone.0068175] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Accepted: 05/24/2013] [Indexed: 12/02/2022] Open
Abstract
The classic isoforms of myelin basic protein (MBP) are essential for the formation and maintenance of myelin in the central nervous system of higher vertebrates. The protein is involved in all facets of the development, compaction, and stabilization of the multilamellar myelin sheath, and also interacts with cytoskeletal and signaling proteins. The predominant 18.5-kDa isoform of MBP is an intrinsically-disordered protein that is a candidate auto-antigen in the human demyelinating disease multiple sclerosis. A highly-conserved central segment within classic MBP consists of a proline-rich region (murine 18.5-kDa sequence -T92-P93-R94-T95-P96-P97-P98-S99-) containing a putative SH3-ligand, adjacent to a region that forms an amphipathic α-helix (P82-I90) upon interaction with membranes, or under membrane-mimetic conditions. The T92 and T95 residues within the proline-rich region can be post-translationally modified through phosphorylation by mitogen-activated protein (MAP) kinases. Here, we have investigated the structure of the α-helical and proline-rich regions in dilute aqueous buffer, and have evaluated the effects of phosphorylation at T92 and T95 on the stability and dynamics of the α-helical region, by utilizing four 36-residue peptides (S72-S107) with differing phosphorylation status. Nuclear magnetic resonance spectroscopy reveals that both the α-helical as well as the proline-rich regions are disordered in aqueous buffer, whereas they are both structured in a lipid environment (cf., Ahmed et al., Biochemistry 51, 7475-9487, 2012). Thermodynamic analysis of trifluoroethanol-titration curves monitored by circular dichroism spectroscopy reveals that phosphorylation, especially at residue T92, impedes formation of the amphipathic α-helix. This conclusion is supported by molecular dynamics simulations, which further illustrate that phosphorylation reduces the folding reversibility of the α-helix upon temperature perturbation and affect the global structure of the peptides through altered electrostatic interactions. The results support the hypothesis that the central conserved segment of MBP constitutes a molecular switch in which the conformation and/or intermolecular interactions are mediated by phosphorylation/dephosphorylation at T92 and T95.
Collapse
Affiliation(s)
- Kenrick A. Vassall
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Kyrylo Bessonov
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Miguel De Avila
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | | | - George Harauz
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| |
Collapse
|
31
|
Ahrendsen JT, Macklin W. Signaling mechanisms regulating myelination in the central nervous system. Neurosci Bull 2013; 29:199-215. [PMID: 23558589 DOI: 10.1007/s12264-013-1322-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Accepted: 02/22/2013] [Indexed: 12/19/2022] Open
Abstract
The precise and coordinated production of myelin is essential for proper development and function of the nervous system. Diseases that disrupt myelin, including multiple sclerosis, cause significant functional disability. Current treatment aims to reduce the inflammatory component of the disease, thereby preventing damage resulting from demyelination. However, therapies are not yet available to improve natural repair processes after damage has already occurred. A thorough understanding of the signaling mechanisms that regulate myelin generation will improve our ability to enhance repair. in this review, we summarize the positive and negative regulators of myelination, focusing primarily on central nervous system myelination. Axon-derived signals, extracellular signals from both diffusible factors and the extracellular matrix, and intracellular signaling pathways within myelinating oligodendrocytes are discussed. Much is known about the positive regulators that drive myelination, while less is known about the negative regulators that shift active myelination to myelin maintenance at the appropriate time. Therefore, we also provide new data on potential negative regulators of CNS myelination.
Collapse
Affiliation(s)
- Jared T Ahrendsen
- Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
| | | |
Collapse
|
32
|
Harauz G, Boggs JM. Myelin management by the 18.5-kDa and 21.5-kDa classic myelin basic protein isoforms. J Neurochem 2013; 125:334-61. [PMID: 23398367 DOI: 10.1111/jnc.12195] [Citation(s) in RCA: 103] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Revised: 02/05/2013] [Accepted: 02/05/2013] [Indexed: 12/15/2022]
Abstract
The classic myelin basic protein (MBP) splice isoforms range in nominal molecular mass from 14 to 21.5 kDa, and arise from the gene in the oligodendrocyte lineage (Golli) in maturing oligodendrocytes. The 18.5-kDa isoform that predominates in adult myelin adheres the cytosolic surfaces of oligodendrocyte membranes together, and forms a two-dimensional molecular sieve restricting protein diffusion into compact myelin. However, this protein has additional roles including cytoskeletal assembly and membrane extension, binding to SH3-domains, participation in Fyn-mediated signaling pathways, sequestration of phosphoinositides, and maintenance of calcium homeostasis. Of the diverse post-translational modifications of this isoform, phosphorylation is the most dynamic, and modulates 18.5-kDa MBP's protein-membrane and protein-protein interactions, indicative of a rich repertoire of functions. In developing and mature myelin, phosphorylation can result in microdomain or even nuclear targeting of the protein, supporting the conclusion that 18.5-kDa MBP has significant roles beyond membrane adhesion. The full-length, early-developmental 21.5-kDa splice isoform is predominantly karyophilic due to a non-traditional P-Y nuclear localization signal, with effects such as promotion of oligodendrocyte proliferation. We discuss in vitro and recent in vivo evidence for multifunctionality of these classic basic proteins of myelin, and argue for a systematic evaluation of the temporal and spatial distributions of these protein isoforms, and their modified variants, during oligodendrocyte differentiation.
Collapse
Affiliation(s)
- George Harauz
- Department of Molecular and Cellular Biology, Biophysics Interdepartmental Group and Collaborative Program in Neuroscience, University of Guelph, Guelph, Ontario, Canada.
| | | |
Collapse
|
33
|
Masaki T. Polarization and myelination in myelinating glia. ISRN NEUROLOGY 2012; 2012:769412. [PMID: 23326681 PMCID: PMC3544266 DOI: 10.5402/2012/769412] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/03/2012] [Accepted: 11/13/2012] [Indexed: 01/13/2023]
Abstract
Myelinating glia, oligodendrocytes in central nervous system and Schwann cells in peripheral nervous system, form myelin sheath, a multilayered membrane system around axons enabling salutatory nerve impulse conduction and maintaining axonal integrity. Myelin sheath is a polarized structure localized in the axonal side and therefore is supposed to be formed based on the preceding polarization of myelinating glia. Thus, myelination process is closely associated with polarization of myelinating glia. However, cell polarization has been less extensively studied in myelinating glia than other cell types such as epithelial cells. The ultimate goal of this paper is to provide insights for the field of myelination research by applying the information obtained in polarity study in other cell types, especially epithelial cells, to cell polarization of myelinating glia. Thus, in this paper, the main aspects of cell polarization study in general are summarized. Then, they will be compared with polarization in oligodendrocytes. Finally, the achievements obtained in polarization study for epithelial cells, oligodendrocytes, and other types of cells will be translated into polarization/myelination process by Schwann cells. Then, based on this model, the perspectives in the study of Schwann cell polarization/myelination will be discussed.
Collapse
Affiliation(s)
- Toshihiro Masaki
- Department of Medical Science, Teikyo University of Science, 2-2-1 Senju-Sakuragi, Adachi-ku, Tokyo 120-0045, Japan
| |
Collapse
|
34
|
Takahashi T, Ito K, Fukushima K, Takaguchi M, Hayakawa T, Suzuki Y, Suzuki T. Sulfatide negatively regulates the fusion process of human parainfluenza virus type 3. J Biochem 2012; 152:373-80. [DOI: 10.1093/jb/mvs080] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
35
|
Smith GST, Homchaudhuri L, Boggs JM, Harauz G. Classic 18.5- and 21.5-kDa myelin basic protein isoforms associate with cytoskeletal and SH3-domain proteins in the immortalized N19-oligodendroglial cell line stimulated by phorbol ester and IGF-1. Neurochem Res 2012; 37:1277-95. [PMID: 22249765 DOI: 10.1007/s11064-011-0700-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2011] [Revised: 11/17/2011] [Accepted: 12/31/2011] [Indexed: 01/10/2023]
Abstract
The 18.5-kDa classic myelin basic protein (MBP) is an intrinsically disordered protein arising from the Golli (Genes of Oligodendrocyte Lineage) gene complex and is responsible for compaction of the myelin sheath in the central nervous system. This MBP splice isoform also has a plethora of post-translational modifications including phosphorylation, deimination, methylation, and deamidation, that reduce its overall net charge and alter its protein and lipid associations within oligodendrocytes (OLGs). It was originally thought that MBP was simply a structural component of myelin; however, additional investigations have demonstrated that MBP is multi-functional, having numerous protein-protein interactions with Ca²⁺-calmodulin, actin, tubulin, and proteins with SH3-domains, and it can tether these proteins to a lipid membrane in vitro. Here, we have examined cytoskeletal interactions of classic 18.5-kDa MBP, in vivo, using early developmental N19-OLGs transfected with fluorescently-tagged MBP, actin, tubulin, and zonula occludens 1 (ZO-1). We show that MBP redistributes to distinct 'membrane-ruffled' regions of the plasma membrane where it co-localizes with actin and tubulin, and with the SH3-domain-containing proteins cortactin and ZO-1, when stimulated with PMA, a potent activator of the protein kinase C pathway. Moreover, using phospho-specific antibody staining, we show an increase in phosphorylated Thr98 MBP (human sequence numbering) in membrane-ruffled OLGs. Previously, Thr98 phosphorylation of MBP has been shown to affect its conformation, interactions with other proteins, and tethering of other proteins to the membrane in vitro. Here, MBP and actin were also co-localized in new focal adhesion contacts induced by IGF-1 stimulation in cells grown on laminin-2. This study supports a role for classic MBP isoforms in cytoskeletal and other protein-protein interactions during membrane and cytoskeletal remodeling in OLGs.
Collapse
Affiliation(s)
- Graham S T Smith
- Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Road East, Guelph, ON N1G 2W1, Canada
| | | | | | | |
Collapse
|
36
|
Smith GS, De Avila M, Paez PM, Spreuer V, Wills MK, Jones N, Boggs JM, Harauz G. Proline substitutions and threonine pseudophosphorylation of the SH3 ligand of 18.5-kDa myelin basic protein decrease its affinity for the Fyn-SH3 domain and alter process development and protein localization in oligodendrocytes. J Neurosci Res 2012; 90:28-47. [PMID: 21887699 PMCID: PMC3527418 DOI: 10.1002/jnr.22733] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2011] [Revised: 06/02/2011] [Accepted: 06/06/2011] [Indexed: 12/28/2022]
Abstract
The developmentally regulated myelin basic proteins (MBPs), which arise from the golli (gene of oligodendrocyte lineage) complex, are highly positively charged, intrinsically disordered, multifunctional proteins having several alternatively spliced isoforms and posttranslational modifications, and they play key roles in myelin compaction. The classic 18.5-kDa MBP isoform has a proline-rich region comprising amino acids 92-99 (murine sequence -T(92)PRTPPPS(99)-) that contains a minimal SH3 ligand domain. We have previously shown that 18.5-kDa MBP binds to several SH3 domains, including that of Fyn, a member of the Src family of tyrosine kinases involved in a number of signaling pathways during CNS development. To determine the physiological role of this binding as well as the role of phosphorylation of Thr92 and Thr95, in the current study we have produced several MBP variants specifically targeting phosphorylation sites and key structural regions of MBP's SH3 ligand domain. Using isothermal titration calorimetry, we have demonstrated that, compared with the wild-type protein, these variants have lower affinity for the SH3 domain of Fyn. Moreover, overexpression of N-terminal-tagged GFP versions in immortalized oligodendroglial N19 and N20.1 cell cultures results in aberrant elongation of membrane processes and increased branching complexity and inhibits the ability of MBP to decrease Ca(2+) influx. Phosphorylation of Thr92 can also cause MBP to traffic to the nucleus, where it may participate in additional protein-protein interactions. Coexpression of MBP with a constitutively active form of Fyn kinase resulted in membrane process elaboration, a phenomenon that was abolished by point amino acid substitutions in MBP's SH3 ligand domain. These results suggest that MBP's SH3 ligand domain plays a key role in intracellular protein interactions in vivo and may be required for proper membrane elaboration of developing oligodendrocytes and, further, that phosphorylation of Thr92 and Thr95 can regulate this function.
Collapse
Affiliation(s)
- Graham S.T. Smith
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Miguel De Avila
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Pablo M. Paez
- Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, California
| | - Vilma Spreuer
- Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, California
| | - Melanie K.B. Wills
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Nina Jones
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Joan M. Boggs
- Molecular Structure and Function, Hospital for Sick Children, and Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - George Harauz
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| |
Collapse
|
37
|
Abstract
BACKGROUND INFORMATION Vaccinia virus (VACV) was used as a surrogate of variola virus (genus Orthopoxvirus), the causative agent of smallpox, to study orthopoxvirus infection. VACV infects cells via attachment and fusion of the viral membrane with the host cell membrane. Glycosphingolipids, expressed in multiple organs, are major components of lipid rafts and have been associated with the infectious route of several pathogens. RESULTS We demonstrate that the VACV-WR (VACV Western-Reserve strain) displays no binding to Cer (ceramide) or to Gal-Cer (galactosylceramide), but binds to a natural sulfated derivative of these molecules: the Sulf (sulfatide) 3' sulfogalactosylceramide. The interaction between Sulf and VACV-WR resulted in a time-dependent inhibition of virus infection. Virus cell attachment was the crucial step inhibited by Sulf. Electron microscopy showed that SUVs (small unilamellar vesicles) enriched in Sulf bound to VACV particles. Both the A27 and L5 viral membrane proteins were shown to interact with Sulf, indicating that they could be the major viral ligands for Sulf. Soluble Sulf was successful in preventing mortality, but not morbidity, in a lethal mouse model infection with VACV-WR. CONCLUSIONS Together the results suggest that Sulf could play a role as an alternate receptor for VACV-WR and probably other Orthopoxviruses.
Collapse
|
38
|
Polverini E, Coll EP, Tieleman DP, Harauz G. Conformational choreography of a molecular switch region in myelin basic protein—Molecular dynamics shows induced folding and secondary structure type conversion upon threonyl phosphorylation in both aqueous and membrane-associated environments. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2011; 1808:674-83. [DOI: 10.1016/j.bbamem.2010.11.030] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2010] [Revised: 11/10/2010] [Accepted: 11/23/2010] [Indexed: 12/12/2022]
|
39
|
Smolders I, Smets I, Maier O, vandeVen M, Steels P, Ameloot M. Simvastatin interferes with process outgrowth and branching of oligodendrocytes. J Neurosci Res 2011; 88:3361-75. [PMID: 20857509 DOI: 10.1002/jnr.22490] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Statins have attracted interest as a treatment option for multiple sclerosis (MS) because of their pleiotropic antiinflammatory and immunomodulatory effects. However, contradictory results have been described when they are applied to oligodendrocytes (OLGs), the cell type predominantly affected in MS. In this study we focus on the in vitro effect of statins on process outgrowth in OLN-93 cells, a well-characterized OLG-derived cell line, and primary cultures of neonatal rat OLGs. Application of the lipophilic simvastatin, as low as 0.1-1 μM, disturbs process formation of both cell types, leading to less ramified cells. We show that both protein isoprenylation and cholesterol synthesis are required for the normal differentiation of OLGs. It is further demonstrated that the expression of 2',3'-cyclic-nucleotide-3' phosphodiesterase (CNP) and tubulin is lowered, concomitant with a reduction of membrane-bound CNP as well as tubulin. Therefore, we propose that lack of isoprenylation of CNP could help to explain the altered morphological and biochemical differentiation state of treated OLGs. Moreover, expression of specific myelin markers, such as myelin basic protein, myelin-associated glycoprotein, and myelin oligodendrocyte glycoprotein, was compromised after treatment. We conclude that simvastatin treatment has detrimental effects on OLG process outgrowth, the prior step in (re)myelination, thereby mortgaging long-term healing of MS lesions.
Collapse
Affiliation(s)
- Inge Smolders
- Biomedical Research Institute, School of Life Sciences, Hasselt University and Transnational University Limburg, Diepenbeek, Belgium
| | | | | | | | | | | |
Collapse
|
40
|
Suresh S, Wang C, Nanekar R, Kursula P, Edwardson JM. Myelin basic protein and myelin protein 2 act synergistically to cause stacking of lipid bilayers. Biochemistry 2010; 49:3456-63. [PMID: 20334434 DOI: 10.1021/bi100128h] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Saltatory conduction of nerve impulses along axonal membranes depends on the presence of a multilayered membrane, myelin, that wraps around the axon. Myelin basic protein (MBP) and myelin protein 2 (P2) are intimately involved in the generation of the myelin sheath. They are also implicated in a number of neurological diseases, including autoimmune diseases of both the central and peripheral nervous systems. Here, we have used atomic force microsopy (AFM) to study the effects of MBP and P2 on lipid bilayers. MBP in association with a mica substrate appeared unstructured, and tended to coat the mica surface in the form of a monolayer. In contrast, P2 appeared as discrete particles, with molecular volumes consistent with the formation of both monomers and dimers. Either MBP or P2, at micromolar concentrations, caused stacking of brain lipid bilayers. This stacking effect was significantly potentiated when both proteins were added together. Bilayers composed of phosphatidylcholine (PC) and phosphatidylserine (PS) were stacked by MBP, provided that cholesterol was also present; in contrast, P2 did not stack PC/PS/cholesterol bilayers. Hence, the bilayer stacking effects of the two proteins have different lipid requirements.
Collapse
Affiliation(s)
- Swetha Suresh
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, United Kingdom
| | | | | | | | | |
Collapse
|
41
|
Homchaudhuri L, Polverini E, Gao W, Harauz G, Boggs JM. Influence of membrane surface charge and post-translational modifications to myelin basic protein on its ability to tether the Fyn-SH3 domain to a membrane in vitro. Biochemistry 2010; 48:2385-93. [PMID: 19178193 DOI: 10.1021/bi8022587] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Myelin basic protein (MBP) is a highly post-translationally modified, multifunctional structural component of central nervous system myelin, adhering to phospholipid membranes and assembling cytoskeletal proteins, and has previously been shown to bind SH3 domains in vitro and tether them to a membrane surface [Polverini, E., et al. (2008) Biochemistry 47, 267-282]. Since molecular modeling shows that the Fyn-SH3 domain has a negative surface charge density even after binding the MBP ligand, we have investigated the influence of negative membrane surface charge and the effects of post-translational modifications to MBP on the interaction of the Fyn-SH3 domain with membrane-associated MBP. Using a sedimentation assay with multilamellar vesicles consisting of neutral phosphatidylcholine (PC) and negatively charged phosphatidylinositol (PI), we demonstrate that increasing the negative surface charge of the membrane by increasing the proportion of PI reduces the amount of Fyn-SH3 domain that binds to membrane-associated MBP, due to electrostatic repulsion. When one of the phosphoinositides, PI(4)P or PI(4,5)P(2) was substituted for PI in equal proportion, none of the Fyn-SH3 domain bound to MBP under the conditions that were used. Post-translational modifications of MBP which reduced its net positive charge, i.e., phosphorylation or arginine deimination, increased the degree of repulsion of Fyn-SH3 from the membrane surface, an effect further modulated by the lipid charge. This study suggests that changes in membrane negative surface charge due to protein or lipid modifications, which could occur during cell signaling, can regulate the binding of the Fyn-SH3 domain to membrane-associated MBP and thus could regulate the activity of Fyn at the oligodendrocyte membrane surface.
Collapse
Affiliation(s)
- Lopamudra Homchaudhuri
- Department of Molecular Structure and Function, Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada M5G 1X8
| | | | | | | | | |
Collapse
|
42
|
Bessonov K, Bamm VV, Harauz G. Misincorporation of the proline homologue Aze (azetidine-2-carboxylic acid) into recombinant myelin basic protein. PHYTOCHEMISTRY 2010; 71:502-507. [PMID: 20064647 DOI: 10.1016/j.phytochem.2009.12.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2009] [Revised: 12/09/2009] [Accepted: 12/15/2009] [Indexed: 05/28/2023]
Abstract
We have evaluated the effects of the proline homologue Aze (1) (azetidine-2-carboxylic acid) on growth of Escherichia coli strains used to over-express recombinant forms of murine myelin basic protein (rmMBP), and on the degree of misincorporation. Addition of Aze to minimal media resulted in severe diminution of growth rate, but rmMBP could still be produced and purified. Mass spectrometry indicated that a detectable proportion of the rmMBP produced had incorporated Aze instead of proline (Pro), to a maximum of three of eleven possible sites. Molecular modelling of a proline-rich region of rmMBP illustrated that the misincorporation of Aze at any site would cause a severe bend in the polypeptide chain, and that multiple Pro-->Aze substitutions would completely disrupt a poly-proline type II structure that has been conjectured to be functionally significant.
Collapse
Affiliation(s)
- Kyrylo Bessonov
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | | | | |
Collapse
|
43
|
On the biogenesis of myelin membranes: sorting, trafficking and cell polarity. FEBS Lett 2009; 584:1760-70. [PMID: 19896485 DOI: 10.1016/j.febslet.2009.10.085] [Citation(s) in RCA: 112] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2009] [Revised: 10/29/2009] [Accepted: 10/30/2009] [Indexed: 11/22/2022]
Abstract
In the central nervous system, a multilayered membrane layer known as the myelin sheath enwraps axons, and is required for optimal saltatory signal conductance. The sheath develops from membrane processes that extend from the plasma membrane of oligodendrocytes and displays a unique lipid and protein composition. Myelin biogenesis is carefully regulated, and multiple transport pathways involving a variety of endosomal compartments are involved. Here we briefly summarize how the major myelin proteins proteolipid protein and myelin basic protein reach the sheath, and highlight potential mechanisms involved, including the role of myelin specific lipids and cell polarity related transport pathways.
Collapse
|
44
|
Harauz G, Ladizhansky V, Boggs JM. Structural Polymorphism and Multifunctionality of Myelin Basic Protein. Biochemistry 2009; 48:8094-104. [DOI: 10.1021/bi901005f] [Citation(s) in RCA: 150] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | | | - Joan M. Boggs
- Department of Molecular Structure and Function, Research Institute, Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada, and Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario M5G 1L5, Canada
| |
Collapse
|
45
|
Abstract
OBJECTIVE To determine in fetal sheep the effect of betamethasone on myelination in relation to stage of myelination, number of treatment courses, dose, and route of administration. METHODS Fetal expression of myelin basic protein (MBP), a marker of mature oligodendrocytes and myelin, was determined between 0.27 and 0.93 gestation. Short-term betamethasone effects were examined 24 hours after one maternal intramuscular treatment course (weight adjusted to equal the clinical dose of 2 x 8 mg betamethasone to a 70-kg woman) at 0.63, 0.75, and 0.87 gestation or after continuous 48-hour fetal intravenous infusion at 0.75 and 0.87 gestation. Lasting effects were examined 20 days after one and two treatment courses weight-adapted to the clinical dose of 2 x 8 mg or 2 x 12 mg betamethasone at 0.75 gestation. RESULTS Myelin basic protein immunoreactivity was first detected in the internal capsule at 0.53 gestation, followed by the centrum semiovale, the superficial white matter, and corpus callosum at 0.63 gestation. Within 24 hours after treatment, betamethasone reduced the number of mature oligodendrocytes and MBP immunoreactivity. The effect decreased with gestational age. Maternal and fetal betamethasone administration had similar effects. Loss of MBP immunoreactivity was not reversed 20 days after two treatment courses, independent of dose. CONCLUSION Betamethasone-induced delayed cerebral myelination is dependent on the stage of brain development in sheep. Betamethasone-related disturbances in myelination and any potential contribution to childhood behavior deficits need to be confirmed in clinical studies.
Collapse
|
46
|
Musse AA, Gao W, Rangaraj G, Boggs JM, Harauz G. Myelin basic protein co-distributes with other PI(4,5)P2-sequestering proteins in Triton X-100 detergent-resistant membrane microdomains. Neurosci Lett 2009; 450:32-6. [DOI: 10.1016/j.neulet.2008.11.022] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2008] [Revised: 11/06/2008] [Accepted: 11/09/2008] [Indexed: 10/21/2022]
|
47
|
Persaud-Sawin DA, Lightcap S, Harry GJ. Isolation of rafts from mouse brain tissue by a detergent-free method. J Lipid Res 2008; 50:759-67. [PMID: 19060326 DOI: 10.1194/jlr.d800037-jlr200] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Membrane rafts are rich in cholesterol and sphingolipids and have specific proteins associated with them. Due to their small size, their identification and isolation have proved to be problematic. Their insolubility in nonionic detergents, such as Triton-X 100, at 4 degrees C has been the most common means of isolation. However, detergent presence can produce artifacts or interfere with ganglioside distribution. The direction is therefore toward the use of detergent-free protocols. We report an optimized method of raft isolation from lipid-rich brain tissue using a detergent-free method. We compared this to Triton-X 100-based isolation along sucrose or Optiprep gradients using the following endpoints: low protein content, high cholesterol content, presence of Flotillin 1 (Flot1), and absence of transferrin receptor (TfR) proteins. These criteria were met in raft fractions isolated in a detergent-free buffer along a sucrose gradient of 5%/35%/42.5%. The use of optiprep gave less consistent results with respect to protein distribution. We demonstrate that clean raft fractions with minimal myelin contamination can be reproducibly obtained in the top three low-density fractions along a sucrose step gradient.
Collapse
Affiliation(s)
- Dixie-Ann Persaud-Sawin
- Laboratory of Molecular Toxicology/Neurotoxicology Group, National Institute of Environmental Health Sciences, RTP, NC 27709, USA.
| | | | | |
Collapse
|
48
|
Fasano A, Amoresano A, Rossano R, Carlone G, Carpentieri A, Liuzzi GM, Pucci P, Riccio P. The different forms of PNS myelin P0 protein within and outside lipid rafts. J Neurochem 2008; 107:291-301. [DOI: 10.1111/j.1471-4159.2008.05598.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
49
|
Phosphorylation of U24 from Human Herpes Virus type 6 (HHV-6) and its potential role in mimicking myelin basic protein (MBP) in multiple sclerosis. FEBS Lett 2008; 582:2685-8. [DOI: 10.1016/j.febslet.2008.06.050] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2008] [Revised: 06/10/2008] [Accepted: 06/11/2008] [Indexed: 01/14/2023]
|
50
|
Abstract
Sulfatide is abundantly expressed in various mammalian organs, including the intestines and trachea, in which influenza A viruses (IAVs) replicate. However, the function of sulfatide in IAV infection remains unknown. Sulfatide is synthesized by two transferases, ceramide galactosyltransferase (CGT) and cerebroside sulfotransferase (CST), and is degraded by arylsulfatase A (ASA). In this study, we demonstrated that sulfatide enhanced IAV replication through efficient translocation of the newly synthesized IAV nucleoprotein (NP) from the nucleus to the cytoplasm, by using genetically produced cells in which sulfatide expression was down-regulated by RNA interference against CST mRNA or overexpression of the ASA gene and in which sulfatide expression was up-regulated by overexpression of both the CST and CGT genes. Treatment of IAV-infected cells with an antisulfatide monoclonal antibody (MAb) or an anti-hemagglutinin (HA) MAb, which blocks the binding of IAV and sulfatide, resulted in a significant reduction in IAV replication and accumulation of the viral NP in the nucleus. Furthermore, antisulfatide MAb protected mice against lethal challenge with pathogenic influenza A/WSN/33 (H1N1) virus. These results indicate that association of sulfatide with HA delivered to the cell surface induces translocation of the newly synthesized IAV ribonucleoprotein complexes from the nucleus to the cytoplasm. Our findings provide new insights into IAV replication and suggest new therapeutic strategies.
Collapse
|