501
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Cole KLH, Early JJ, Lyons DA. Drug discovery for remyelination and treatment of MS. Glia 2017; 65:1565-1589. [PMID: 28618073 DOI: 10.1002/glia.23166] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 04/20/2017] [Accepted: 04/24/2017] [Indexed: 12/19/2022]
Abstract
Glia constitute the majority of the cells in our nervous system, yet there are currently no drugs that target glia for the treatment of disease. Given ongoing discoveries of the many roles of glia in numerous diseases of the nervous system, this is likely to change in years to come. Here we focus on the possibility that targeting the oligodendrocyte lineage to promote regeneration of myelin (remyelination) represents a therapeutic strategy for the treatment of the demyelinating disease multiple sclerosis, MS. We discuss how hypothesis driven studies have identified multiple targets and pathways that can be manipulated to promote remyelination in vivo, and how this work has led to the first ever remyelination clinical trials. We also highlight how recent chemical discovery screens have identified a host of small molecule compounds that promote oligodendrocyte differentiation in vitro. Some of these compounds have also been shown to promote myelin regeneration in vivo, with one already being trialled in humans. Promoting oligodendrocyte differentiation and remyelination represents just one potential strategy for the treatment of MS. The pathology of MS is complex, and its complete amelioration may require targeting multiple biological processes in parallel. Therefore, we present an overview of new technologies and models for phenotypic analyses and screening that can be exploited to study complex cell-cell interactions in in vitro and in vivo systems. Such technological platforms will provide insight into fundamental mechanisms and increase capacities for drug-discovery of relevance to glia and currently intractable disorders of the CNS.
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Affiliation(s)
- Katy L H Cole
- Centre for Neuroregeneration, MS Society Centre for Translational Research, Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, Edinburgh, EH16 4SB, United Kingdom
| | - Jason J Early
- Centre for Neuroregeneration, MS Society Centre for Translational Research, Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, Edinburgh, EH16 4SB, United Kingdom
| | - David A Lyons
- Centre for Neuroregeneration, MS Society Centre for Translational Research, Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, Edinburgh, EH16 4SB, United Kingdom
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502
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Logan AM, Mammel AE, Robinson DC, Chin AL, Condon AF, Robinson FL. Schwann cell-specific deletion of the endosomal PI 3-kinase Vps34 leads to delayed radial sorting of axons, arrested myelination, and abnormal ErbB2-ErbB3 tyrosine kinase signaling. Glia 2017; 65:1452-1470. [PMID: 28617998 DOI: 10.1002/glia.23173] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2016] [Revised: 05/04/2017] [Accepted: 05/10/2017] [Indexed: 12/12/2022]
Abstract
The PI 3-kinase Vps34 (Pik3c3) synthesizes phosphatidylinositol 3-phosphate (PI3P), a lipid critical for both endosomal membrane traffic and macroautophagy. Human genetics have implicated PI3P dysregulation, and endosomal trafficking in general, as a recurring cause of demyelinating Charcot-Marie-Tooth (CMT) peripheral neuropathy. Here, we investigated the role of Vps34, and PI3P, in mouse Schwann cells by selectively deleting Vps34 in this cell type. Vps34-Schwann cell knockout (Vps34SCKO ) mice show severe hypomyelination in peripheral nerves. Vps34-/- Schwann cells interact abnormally with axons, and there is a delay in radial sorting, a process by which large axons are selected for myelination. Upon reaching the promyelinating stage, Vps34-/- Schwann cells are significantly impaired in the elaboration of myelin. Nerves from Vps34SCKO mice contain elevated levels of the LC3 and p62 proteins, indicating impaired autophagy. However, in the light of recent demonstrations that autophagy is dispensable for myelination, it is unlikely that hypomyelination in Vps34SCKO mice is caused by impaired autophagy. Endosomal trafficking is also disturbed in Vps34-/- Schwann cells. We investigated the activation of the ErbB2/3 receptor tyrosine kinases in Vps34SCKO nerves, as these proteins, which play essential roles in Schwann cell myelination, are known to traffic through endosomes. In Vps34SCKO nerves, ErbB3 was hyperphosphorylated on a tyrosine known to be phosphorylated in response to neuregulin 1 exposure. ErbB2 protein levels were also decreased during myelination. Our findings suggest that the loss of Vps34 alters the trafficking of ErbB2/3 through endosomes. Abnormal ErbB2/3 signaling to downstream targets may contribute to the hypomyelination observed in Vps34SCKO mice.
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Affiliation(s)
- Anne M Logan
- Department of Neurology, Jungers Center for Neurosciences Research, Oregon Health and Science University, Mail Code L623, Portland, Oregon, 97239.,Neuroscience Graduate Program, Oregon Health and Science University, Portland, Oregon, 97239
| | - Anna E Mammel
- Department of Neurology, Jungers Center for Neurosciences Research, Oregon Health and Science University, Mail Code L623, Portland, Oregon, 97239.,Cell, Developmental and Cancer Biology Graduate Program, Oregon Health and Science University, Portland, Oregon, 97239
| | - Danielle C Robinson
- Department of Neurology, Jungers Center for Neurosciences Research, Oregon Health and Science University, Mail Code L623, Portland, Oregon, 97239.,Neuroscience Graduate Program, Oregon Health and Science University, Portland, Oregon, 97239
| | - Andrea L Chin
- Department of Neurology, Jungers Center for Neurosciences Research, Oregon Health and Science University, Mail Code L623, Portland, Oregon, 97239
| | - Alec F Condon
- Department of Neurology, Jungers Center for Neurosciences Research, Oregon Health and Science University, Mail Code L623, Portland, Oregon, 97239.,Neuroscience Graduate Program, Oregon Health and Science University, Portland, Oregon, 97239
| | - Fred L Robinson
- Department of Neurology, Jungers Center for Neurosciences Research, Oregon Health and Science University, Mail Code L623, Portland, Oregon, 97239.,Vollum Institute, Oregon Health and Science University, Portland, Oregon, 97239
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503
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Neuropathies in the setting of Neurofibromatosis tumor syndromes: Complexities and opportunities. Exp Neurol 2017; 299:334-344. [PMID: 28587874 DOI: 10.1016/j.expneurol.2017.06.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2017] [Revised: 05/03/2017] [Accepted: 06/02/2017] [Indexed: 12/11/2022]
Abstract
The term 'Neurofibromatosis' (NF) comprises a group of rare diseases with related clinical presentations but distinct genetic conditions. All currently known types - NF1, NF2 and Schwannomatosis - predispose afflicted individuals to the development of glial cell-derived (gliogenic) tumors. Furthermore, the occurrence of neuropathic symptoms, which add to the overall neurologic disability of patients, has been described in all disease entities. We show that neuropathic symptoms are a common and clinically important, yet infrequently studied feature in the NF spectrum. However, the clinical relevance and respective underlying pathogenesis, varies greatly among the different NF types. In this review, we summarize and interpret the latest basic research findings, as well as clinical observations, in respect of Neurofibromatosis-associated neuropathies.
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504
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Tatsi C, Bacopoulou F, Lyssikatos C, Belyavskaya E, Faucz F, Stratakis CA. Sporadic melanotic schwannoma with overlapping features of melanocytoma bearing a GNA11 mutation in an adolescent girl. Pediatr Blood Cancer 2017; 64:10.1002/pbc.26400. [PMID: 28012237 PMCID: PMC6309823 DOI: 10.1002/pbc.26400] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Revised: 10/08/2016] [Accepted: 10/13/2016] [Indexed: 12/23/2022]
Abstract
Melanotic schwannoma (MS) is a soft tissue neoplasm that shares histologic features with melanocytic tumors and schwannomas. A type of MS, called psammomatous MS (PMS), is associated with Carney complex (CNC), which is caused by PRKAR1A mutations. Other pigmented neoplasms, such as uveal melanomas and melanocytomas (MCs), are associated with genetic defects in other genes including GNA11. We report an adolescent female with a large sporadic mesenteric MS with complex histologic findings reminiscent of both PMS and MC. The lesion carried a mutation of the GNA11 gene. We conclude that sporadic MSs may occur rarely in adolescents without CNC; MSs may also be associated with somatic GNA11 mutations.
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Affiliation(s)
- Christina Tatsi
- Section on Endocrinology & Genetics, and Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD 20892, USA.,Pediatric Endocrinology Inter-institute Training Program, Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD 20892, USA.,To whom correspondence should be addressed: Dr. Christina Tatsi, SEGEN, NICHD, NIH, 10 Center Drive, Building 10, NIH-Clinical Research Center, Room 1-3330, MSC1103, Bethesda, MD, 20892-1862,USA, Tel: 001-301-496-4686; 001-301-402-0574,
| | - Flora Bacopoulou
- Pediatric Endocrinology Inter-institute Training Program, Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD 20892, USA.,First Department of Pediatrics, National and Kapodistrian University of Athens, Aghia Sophia Children’s Hospital, Athens, Greece
| | - Charalampos Lyssikatos
- Pediatric Endocrinology Inter-institute Training Program, Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD 20892, USA
| | - Elena Belyavskaya
- Pediatric Endocrinology Inter-institute Training Program, Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD 20892, USA
| | - Fabio Faucz
- Pediatric Endocrinology Inter-institute Training Program, Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD 20892, USA
| | - Constantine A. Stratakis
- Section on Endocrinology & Genetics, and Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD 20892, USA.,Pediatric Endocrinology Inter-institute Training Program, Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD 20892, USA
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505
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Faissner A, Roll L, Theocharidis U. Tenascin-C in the matrisome of neural stem and progenitor cells. Mol Cell Neurosci 2017; 81:22-31. [DOI: 10.1016/j.mcn.2016.11.003] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 11/03/2016] [Accepted: 11/07/2016] [Indexed: 01/16/2023] Open
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506
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Camargo N, Goudriaan A, van Deijk ALF, Otte WM, Brouwers JF, Lodder H, Gutmann DH, Nave KA, Dijkhuizen RM, Mansvelder HD, Chrast R, Smit AB, Verheijen MHG. Oligodendroglial myelination requires astrocyte-derived lipids. PLoS Biol 2017; 15:e1002605. [PMID: 28549068 PMCID: PMC5446120 DOI: 10.1371/journal.pbio.1002605] [Citation(s) in RCA: 167] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 04/25/2017] [Indexed: 11/18/2022] Open
Abstract
In the vertebrate nervous system, myelination of axons for rapid impulse propagation requires the synthesis of large amounts of lipids and proteins by oligodendrocytes and Schwann cells. Myelin membranes are thought to be cell-autonomously assembled by these axon-associated glial cells. Here, we report the surprising finding that in normal brain development, a substantial fraction of the lipids incorporated into central nervous system (CNS) myelin are contributed by astrocytes. The oligodendrocyte-specific inactivation of sterol regulatory element-binding protein (SREBP) cleavage-activating protein (SCAP), an essential coactivator of the transcription factor SREBP and thus of lipid biosynthesis, resulted in significantly retarded CNS myelination; however, myelin appeared normal at 3 months of age. Importantly, embryonic deletion of the same gene in astrocytes, or in astrocytes and oligodendrocytes, caused a persistent hypomyelination, as did deletion from astrocytes during postnatal development. Moreover, when astroglial lipid synthesis was inhibited, oligodendrocytes began incorporating circulating lipids into myelin membranes. Indeed, a lipid-enriched diet was sufficient to rescue hypomyelination in these conditional mouse mutants. We conclude that lipid synthesis by oligodendrocytes is heavily supplemented by astrocytes in vivo and that horizontal lipid flux is a major feature of normal brain development and myelination.
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Affiliation(s)
- Nutabi Camargo
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University Amsterdam, Amsterdam, the Netherlands
| | - Andrea Goudriaan
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University Amsterdam, Amsterdam, the Netherlands
| | - Anne-Lieke F. van Deijk
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University Amsterdam, Amsterdam, the Netherlands
| | - Willem M. Otte
- Biomedical MR Imaging and Spectroscopy group, Center for Image Sciences, University Medical Center Utrecht, Utrecht, the Netherlands
- Department of Pediatric Neurology, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Jos F. Brouwers
- Department of Biochemistry and Cell Biology, Faculty of Veterinary Medicine, Utrecht University, the Netherlands
| | - Hans Lodder
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University Amsterdam, Amsterdam, the Netherlands
| | - David H. Gutmann
- Department of Neurology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Klaus-Armin Nave
- Max-Planck-Institute of Experimental Medicine, Department of Neurogenetics, Goettingen, Germany
| | - Rick M. Dijkhuizen
- Biomedical MR Imaging and Spectroscopy group, Center for Image Sciences, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Huibert D. Mansvelder
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University Amsterdam, Amsterdam, the Netherlands
| | - Roman Chrast
- Department of Neuroscience and Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - August B. Smit
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University Amsterdam, Amsterdam, the Netherlands
| | - Mark H. G. Verheijen
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University Amsterdam, Amsterdam, the Netherlands
- * E-mail:
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507
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Cashman CR, Hoke A. Deficiency of adaptive immunity does not interfere with Wallerian degeneration. PLoS One 2017; 12:e0177070. [PMID: 28475650 PMCID: PMC5419593 DOI: 10.1371/journal.pone.0177070] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Accepted: 04/22/2017] [Indexed: 11/19/2022] Open
Abstract
Following injury, distal axons undergo the process of Wallerian degeneration, and then cell debris is cleared to create a permissive environment for axon regeneration. The innate and adaptive immune systems are believed to be critical for facilitating the clearance of myelin and axonal debris during this process. However, immunodeficient animal models are regularly used in transplantation studies investigating cell therapies to modulate the degenerative/regenerative response. Given the importance of the immune system in preparing a permissive environment for regeneration by clearing debris, animals lacking, in part or in full, a functional immune system may have an impaired ability to regenerate due to poor myelin clearance, and may, thus, be poor hosts to study modulators of regeneration and degeneration. To study this hypothesis, three different mouse models with impaired adaptive immunity were compared to wild type animals in their ability to degenerate axons and clear myelin debris one week following sciatic nerve transection. Immunofluorescent staining for axons and quantitation of axon density with nerve histomorphometry of the distal stump showed no consistent discrepancy between immunodeficient and wild type animals, suggesting axons tended to degenerate equally between the two groups. Debris clearance was assessed by macrophage density and relative myelin basic protein expression within the denervated nerve stump, and no consistent impairment of debris clearance was found. These data suggested deficiency of the adaptive immune system does not have a substantial effect on axon degeneration one week following axonal injury.
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Affiliation(s)
- Christopher R. Cashman
- MSTP/MD-PhD Program, Johns Hopkins School of Medicine, Baltimore, Maryland, United States of America
- Department of Neuroscience, Johns Hopkins School of Medicine, Baltimore, Maryland, United States of America
- Department of Neurology, Johns Hopkins School of Medicine, Baltimore, Maryland, United States of America
| | - Ahmet Hoke
- Department of Neuroscience, Johns Hopkins School of Medicine, Baltimore, Maryland, United States of America
- Department of Neurology, Johns Hopkins School of Medicine, Baltimore, Maryland, United States of America
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508
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Jeon SJ, Ryu JH, Bahn GH. Altered Translational Control of Fragile X Mental Retardation Protein on Myelin Proteins in Neuropsychiatric Disorders. Biomol Ther (Seoul) 2017; 25:231-238. [PMID: 27829268 PMCID: PMC5424632 DOI: 10.4062/biomolther.2016.042] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2016] [Revised: 06/28/2016] [Accepted: 07/28/2016] [Indexed: 01/07/2023] Open
Abstract
Myelin is a specialized structure of the nervous system that both enhances electrical conductance and insulates neurons from external risk factors. In the central nervous system, polarized oligodendrocytes form myelin by wrapping processes in a spiral pattern around neuronal axons through myelin-related gene regulation. Since these events occur at a distance from the cell body, post-transcriptional control of gene expression has strategic advantage to fine-tune the overall regulation of protein contents in situ. Therefore, many research interests have been focused to identify RNA binding proteins and their regulatory mechanism in myelinating compartments. Fragile X mental retardation protein (FMRP) is one such RNA binding protein, regulating its target expression by translational control. Although the majority of works on FMRP have been performed in neurons, it is also found in the developing or mature glial cells including oligodendrocytes, where its function is not well understood. Here, we will review evidences suggesting abnormal translational regulation of myelin proteins with accompanying white matter problem and neurological deficits in fragile X syndrome, which can have wider mechanistic and pathological implication in many other neurological and psychiatric disorders.
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Affiliation(s)
- Se Jin Jeon
- Department of Life and Nanopharmaceutical Science, College of Pharmacy, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Jong Hoon Ryu
- Department of Life and Nanopharmaceutical Science, College of Pharmacy, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Geon Ho Bahn
- Department of Neuropsychiatry, School of Medicine, Kyung Hee University, Seoul 02447, Republic of Korea
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509
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Ulc A, Gottschling C, Schäfer I, Wegrzyn D, van Leeuwen S, Luft V, Reinhard J, Faissner A. Involvement of the guanine nucleotide exchange factor Vav3 in central nervous system development and plasticity. Biol Chem 2017; 398:663-675. [DOI: 10.1515/hsz-2016-0275] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 02/10/2017] [Indexed: 12/13/2022]
Abstract
Abstract
Small GTP-hydrolyzing enzymes (GTPases) of the RhoA family play manifold roles in cell biology and are regulated by upstream guanine nucleotide exchange factors (GEFs). Herein, we focus on the GEFs of the Vav subfamily. Vav1 was originally described as a proto-oncogene of the hematopoietic lineage. The GEFs Vav2 and Vav3 are more broadly expressed in various tissues. In particular, the GEF Vav3 may play important roles in the developing nervous system during the differentiation of neural stem cells into the major lineages, namely neurons, oligodendrocytes and astrocytes. We discuss its putative regulatory roles for progenitor differentiation in the developing retina, polarization of neurons and formation of synapses, migration of oligodendrocyte progenitors and establishment of myelin sheaths. We propose that Vav3 mediates the response of various neural cell types to environmental cues.
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510
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Staudt M, Diederich JM, Meisel C, Meisel A, Klehmet J. Differences in peripheral myelin antigen-specific T cell responses and T memory subsets in atypical versus typical CIDP. BMC Neurol 2017; 17:81. [PMID: 28446142 PMCID: PMC5406908 DOI: 10.1186/s12883-017-0860-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Accepted: 04/19/2017] [Indexed: 12/18/2022] Open
Abstract
Background Chronic inflammatory demyelinating polyneuropathy (CIDP) is presented by a large heterogeneity of clinical phenotypes. Around 50% of patients suffer from typical CIDP and show better therapy response than atypical variants. The goal of our study was to search for cellular immunological differences in typical versus atypical CIDP in comparison to controls. Methods We evaluated 26 (9 typical, 17 atypical) patients with mainly active-unstable CIDP using clinical and immunological examinations (enzyme-linked immunospot assay ELISPOT, fluorescence-activated cell sorting FACS) in comparison to 28 healthy, age-matched controls (HC). Typical or atypical CIDP measurements were compared with HC using Kruskal-Wallis test. Results Atypical CIDP patients showed increased frequencies of T cell subsets, especially CD4+ effector memory T cells (TEM) and CD4+ central memory T cells (TCM) as well as a tendency of higher T cell responses against the peripheral myelin antigens of PMP-22, P2, P0 and MBP peptides compared to typical CIDP. Searching for novel auto-antigens, we found that T cell responses against P0 180-199 as well as MBP 82-100 were significantly elevated in atypical CIDP patients vs. HC. Conclusions Our results indicate differences in underlying T cell responses between atypical and typical CIDP characterized by a higher peripheral myelin antigen-specific T cell responses as well as a specific altered CD4+ memory compartment in atypical CIDP. Larger multi-center studies study are warranted in order to characterize T cell auto-reactivity in atypical CIDP subgroups in order to establish immunological markers as a diagnostic tool.
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Affiliation(s)
- M Staudt
- Department of Neurology, Charité University Medicine, Charitéplatz 1, 10117, Berlin, Germany
| | - J M Diederich
- Department of Neurology, Charité University Medicine, Charitéplatz 1, 10117, Berlin, Germany
| | - C Meisel
- Department of Clinical Immunology, Charité University Medicine, Charitéplatz 1, Berlin, Germany
| | - A Meisel
- Department of Neurology, Charité University Medicine, Charitéplatz 1, 10117, Berlin, Germany
| | - J Klehmet
- Department of Neurology, Charité University Medicine, Charitéplatz 1, 10117, Berlin, Germany.
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511
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Jagielska A, Lowe AL, Makhija E, Wroblewska L, Guck J, Franklin RJM, Shivashankar GV, Van Vliet KJ. Mechanical Strain Promotes Oligodendrocyte Differentiation by Global Changes of Gene Expression. Front Cell Neurosci 2017; 11:93. [PMID: 28473753 PMCID: PMC5397481 DOI: 10.3389/fncel.2017.00093] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Accepted: 03/20/2017] [Indexed: 11/13/2022] Open
Abstract
Differentiation of oligodendrocyte progenitor cells (OPC) to oligodendrocytes and subsequent axon myelination are critical steps in vertebrate central nervous system (CNS) development and regeneration. Growing evidence supports the significance of mechanical factors in oligodendrocyte biology. Here, we explore the effect of mechanical strains within physiological range on OPC proliferation and differentiation, and strain-associated changes in chromatin structure, epigenetics, and gene expression. Sustained tensile strain of 10-15% inhibited OPC proliferation and promoted differentiation into oligodendrocytes. This response to strain required specific interactions of OPCs with extracellular matrix ligands. Applied strain induced changes in nuclear shape, chromatin organization, and resulted in enhanced histone deacetylation, consistent with increased oligodendrocyte differentiation. This response was concurrent with increased mRNA levels of the epigenetic modifier histone deacetylase Hdac11. Inhibition of HDAC proteins eliminated the strain-mediated increase of OPC differentiation, demonstrating a role of HDACs in mechanotransduction of strain to chromatin. RNA sequencing revealed global changes in gene expression associated with strain. Specifically, expression of multiple genes associated with oligodendrocyte differentiation and axon-oligodendrocyte interactions was increased, including cell surface ligands (Ncam, ephrins), cyto- and nucleo-skeleton genes (Fyn, actinins, myosin, nesprin, Sun1), transcription factors (Sox10, Zfp191, Nkx2.2), and myelin genes (Cnp, Plp, Mag). These findings show how mechanical strain can be transmitted to the nucleus to promote oligodendrocyte differentiation, and identify the global landscape of signaling pathways involved in mechanotransduction. These data provide a source of potential new therapeutic avenues to enhance OPC differentiation in vivo.
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Affiliation(s)
- Anna Jagielska
- Department of Materials Science and Engineering, Massachusetts Institute of TechnologyCambridge, MA, USA
| | - Alexis L Lowe
- Department of Neuroscience, Wellesley CollegeWellesley, MA, USA
| | - Ekta Makhija
- Mechanobiology Institute, National University of SingaporeSingapore, Singapore
| | - Liliana Wroblewska
- Department of Biological Engineering, Massachusetts Institute of TechnologyCambridge, MA, USA
| | - Jochen Guck
- Biotechnology Center, Technische Universität DresdenDresden, Germany
| | - Robin J M Franklin
- Wellcome Trust - Medical Research Council Cambridge Stem Cell Institute and Department of Clinical Neurosciences, University of CambridgeCambridge, UK
| | - G V Shivashankar
- Mechanobiology Institute, National University of SingaporeSingapore, Singapore
| | - Krystyn J Van Vliet
- Department of Materials Science and Engineering, Massachusetts Institute of TechnologyCambridge, MA, USA.,Department of Biological Engineering, Massachusetts Institute of TechnologyCambridge, MA, USA.,BioSystems and Micromechanics Inter-Disciplinary Research Group, Singapore-MIT Alliance for Research and TechnologySingapore, Singapore
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512
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Methylthioadenosine promotes remyelination by inducing oligodendrocyte differentiation. ACTA ACUST UNITED AC 2017. [DOI: 10.1186/s40893-017-0020-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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513
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Klingseisen A, Lyons DA. Axonal Regulation of Central Nervous System Myelination: Structure and Function. Neuroscientist 2017; 24:7-21. [PMID: 28397586 DOI: 10.1177/1073858417703030] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Approximately half of the human brain consists of myelinated axons. Central nervous system (CNS) myelin is made by oligodendrocytes and is essential for nervous system formation, health, and function. Once thought simply as a static insulator that facilitated rapid impulse conduction, myelin is now known to be made and remodeled in to adult life. Oligodendrocytes have a remarkable capacity to differentiate by default, but many aspects of their development can be influenced by axons. However, how axons and oligodendrocytes interact and cooperate to regulate myelination in the CNS remains unclear. Here, we review recent advances in our understanding of how such interactions generate the complexity of myelination known to exist in vivo. We highlight intriguing results that indicate that the cross-sectional size of an axon alone may regulate myelination to a surprising degree. We also review new studies, which have highlighted diversity in the myelination of axons of different neuronal subtypes and circuits, and structure-function relationships, which suggest that myelinated axons can be exquisitely fine-tuned to mediate precise conduction needs. We also discuss recent advances in our understanding of how neuronal activity regulates CNS myelination, and aim to provide an integrated overview of how axon-oligodendrocyte interactions sculpt neuronal circuit structure and function.
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Affiliation(s)
- Anna Klingseisen
- 1 Centre for Neuroregeneration, University of Edinburgh, Edinburgh, UK
| | - David A Lyons
- 1 Centre for Neuroregeneration, University of Edinburgh, Edinburgh, UK
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514
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Cermenati G, Giatti S, Audano M, Pesaresi M, Spezzano R, Caruso D, Mitro N, Melcangi RC. Diabetes alters myelin lipid profile in rat cerebral cortex: Protective effects of dihydroprogesterone. J Steroid Biochem Mol Biol 2017; 168:60-70. [PMID: 28167298 DOI: 10.1016/j.jsbmb.2017.02.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2016] [Revised: 01/31/2017] [Accepted: 02/02/2017] [Indexed: 12/31/2022]
Abstract
Due to the emerging association of diabetes with several psychiatric and neurodegenerative events, the evaluation of the effects of this pathology on the brain function has now a high priority in biomedical research. In particular, the effects of diabetes on myelin compartment have been poorly taken into consideration. To this purpose, we performed a deep lipidomic analysis of cortical myelin in the streptozotocin-induced diabetic rat model. In male rats three months of diabetes induced an extensive alterations in levels of phosphatidylcholines and phosphatidylethanolamines (the main species present in myelin membranes), plasmalogens as well as phosphatidylinositols and phosphatidylserines. In addition, the levels of cholesterol and myelin basic protein were also decreased. Because these lipids exert important functional and structural roles in the myelin compartment, our data indicate that cerebral cortex myelin is severely compromised in diabetic status. Treatment for one-month with a metabolite of progesterone, dihydroprogesterone, restored the lipid and protein myelin profiles to the levels observed in non-diabetic animals. These data suggest the potential of therapeutic efficacy of DHP to restore myelin in the diabetic brain.
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Affiliation(s)
- Gaia Cermenati
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milano, Italy
| | - Silvia Giatti
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milano, Italy
| | - Matteo Audano
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milano, Italy
| | - Marzia Pesaresi
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milano, Italy
| | - Roberto Spezzano
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milano, Italy
| | - Donatella Caruso
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milano, Italy
| | - Nico Mitro
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milano, Italy.
| | - Roberto Cosimo Melcangi
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milano, Italy.
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515
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Pathogenesis of white matter changes in cerebral small vessel diseases: beyond vessel-intrinsic mechanisms. Clin Sci (Lond) 2017; 131:635-651. [DOI: 10.1042/cs20160380] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2016] [Revised: 01/04/2017] [Accepted: 01/16/2017] [Indexed: 01/08/2023]
Abstract
Cerebral small vessel diseases (SVDs) are a leading cause of age and hypertension-related stroke and dementia. The salient features of SVDs visible on conventional brain magnetic resonance images include white matter hyperintensities (WMHs) on T2-weighted images, small infarcts, macrohemorrhages, dilated perivascular spaces, microbleeds and brain atrophy. Among these, WMHs are the most common and often the earliest brain tissue changes. Moreover, over the past two decades, large population- and patient-based studies have established the clinical importance of WMHs, notably with respect to cognitive and motor disturbances. Here, we seek to provide a new and critical look at the pathogenesis of SVD-associated white matter (WM) changes. We first review our current knowledge of WM biology in the healthy brain, and then consider the main clinical and pathological features of WM changes in SVDs. The most widely held view is that SVD-associated WM lesions are caused by chronic hypoperfusion, impaired cerebrovascular reactivity (CVR) or blood–brain barrier (BBB) leakage. Here, we assess the arguments for and against each of these mechanisms based on population, patient and experimental model studies, and further discuss other potential mechanisms. Specifically, building on two recent seminal studies that have uncovered an anatomical and functional relationship between oligodendrocyte progenitor cells and blood vessels, we elaborate on how small vessel changes might compromise myelin remodelling and cause WM degeneration. Finally, we propose new directions for future studies on this hot research topic.
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516
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Feldman EL, Nave KA, Jensen TS, Bennett DLH. New Horizons in Diabetic Neuropathy: Mechanisms, Bioenergetics, and Pain. Neuron 2017; 93:1296-1313. [PMID: 28334605 PMCID: PMC5400015 DOI: 10.1016/j.neuron.2017.02.005] [Citation(s) in RCA: 527] [Impact Index Per Article: 75.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Revised: 02/02/2017] [Accepted: 02/02/2017] [Indexed: 12/13/2022]
Abstract
Pre-diabetes and diabetes are a global epidemic, and the associated neuropathic complications create a substantial burden on both the afflicted patients and society as a whole. Given the enormity of the problem and the lack of effective therapies, there is a pressing need to understand the mechanisms underlying diabetic neuropathy (DN). In this review, we present the structural components of the peripheral nervous system that underlie its susceptibility to metabolic insults and then discuss the pathways that contribute to peripheral nerve injury in DN. We also discuss systems biology insights gleaned from the recent advances in biotechnology and bioinformatics, emerging ideas centered on the axon-Schwann cell relationship and associated bioenergetic crosstalk, and the rapid expansion of our knowledge of the mechanisms contributing to neuropathic pain in diabetes. These recent advances in our understanding of DN pathogenesis are paving the way for critical mechanism-based therapy development.
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Affiliation(s)
- Eva L Feldman
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109, USA.
| | - Klaus-Armin Nave
- Department of Neurogenetics, Max Planck Institute for Experimental Medicine, 37075 Göttingen, Germany
| | - Troels S Jensen
- Department of Neurology and Danish Pain Research Center, Aarhus University, 8000 Aarhus C, Denmark
| | - David L H Bennett
- Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford OX3 9DU, UK
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517
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Morton PD, Ishibashi N, Jonas RA. Neurodevelopmental Abnormalities and Congenital Heart Disease: Insights Into Altered Brain Maturation. Circ Res 2017; 120:960-977. [PMID: 28302742 PMCID: PMC5409515 DOI: 10.1161/circresaha.116.309048] [Citation(s) in RCA: 115] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Revised: 12/14/2016] [Accepted: 12/15/2016] [Indexed: 01/14/2023]
Abstract
In the past 2 decades, it has become evident that individuals born with congenital heart disease (CHD) are at risk of developing life-long neurological deficits. Multifactorial risk factors contributing to neurodevelopmental abnormalities associated with CHD have been identified; however, the underlying causes remain largely unknown, and efforts to address this issue have only recently begun. There has been a dramatic shift in focus from newly acquired brain injuries associated with corrective and palliative heart surgery to antenatal and preoperative factors governing altered brain maturation in CHD. In this review, we describe key time windows of development during which the immature brain is vulnerable to injury. Special emphasis is placed on the dynamic nature of cellular events and how CHD may adversely impact the cellular units and networks necessary for proper cognitive and motor function. In addition, we describe current gaps in knowledge and offer perspectives about what can be done to improve our understanding of neurological deficits in CHD. Ultimately, a multidisciplinary approach will be essential to prevent or improve adverse neurodevelopmental outcomes in individuals surviving CHD.
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Affiliation(s)
- Paul D Morton
- From the Center for Neuroscience Research and Children's National Heart Institute, Children's National Health System, Washington, DC
| | - Nobuyuki Ishibashi
- From the Center for Neuroscience Research and Children's National Heart Institute, Children's National Health System, Washington, DC.
| | - Richard A Jonas
- From the Center for Neuroscience Research and Children's National Heart Institute, Children's National Health System, Washington, DC.
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518
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Hattori T, Kaji M, Ishii H, Jureepon R, Takarada-Iemata M, Minh Ta H, Manh Le T, Konno A, Hirai H, Shiraishi Y, Ozaki N, Yamamoto Y, Okamoto H, Yokoyama S, Higashida H, Kitao Y, Hori O. CD38 positively regulates postnatal development of astrocytes cell-autonomously and oligodendrocytes non-cell-autonomously. Glia 2017; 65:974-989. [PMID: 28295574 DOI: 10.1002/glia.23139] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2016] [Revised: 02/20/2017] [Accepted: 02/20/2017] [Indexed: 12/11/2022]
Abstract
Glial development is critical for the function of the central nervous system. CD38 is a multifunctional molecule with ADP-ribosyl cyclase activity. While critical roles of CD38 in the adult brain such as oxytocin release and social behavior have been reported, those in the developing brain remain largely unknown. Here we demonstrate that deletion of Cd38 leads to impaired development of astrocytes and oligodendrocytes in mice. CD38 is highly expressed in the developing brains between postnatal day 14 (P14) and day 28 (P28). In situ hybridization and FACS analysis revealed that CD38 is expressed predominantly in astrocytes in these periods. Analyses of the cortex of Cd38 knockout (Cd38-/- ) mice revealed delayed development of astrocytes and subsequently delayed differentiation of oligodendrocytes (OLs) at postnatal stages. In vitro experiments using primary OL cultures, mixed glial cultures, and astrocytic conditioned medium showed that astrocytic CD38 regulates the development of astrocytes in a cell-autonomous manner and the differentiation of OLs in a non-cell-autonomous manner. Further experiments revealed that connexin43 (Cx43) in astrocytes plays a promotive role for CD38-mediated OL differentiation. Finally, increased levels of NAD+ , caused by CD38 deficiency, are likely to be responsible for the suppression of astrocytic Cx43 expression and OL differentiation. Our data indicate that CD38 is a positive regulator of astrocyte and OL development.
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Affiliation(s)
- Tsuyoshi Hattori
- Department of Neuroanatomy, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Minoru Kaji
- Department of Neuroanatomy, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Hiroshi Ishii
- Department of Neuroanatomy, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Roboon Jureepon
- Department of Neuroanatomy, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Mika Takarada-Iemata
- Department of Neuroanatomy, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Hieu Minh Ta
- Department of Neuroanatomy, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Thuong Manh Le
- Department of Neuroanatomy, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Ayumu Konno
- Department of Neurophysiology and Neural Repair, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan
| | - Hirokazu Hirai
- Department of Neurophysiology and Neural Repair, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan
| | - Yoshitake Shiraishi
- Department of Functional Anatomy, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Noriyuki Ozaki
- Department of Functional Anatomy, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Yasuhiko Yamamoto
- Department of Biochemistry and Molecular Vascular Biology, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Hiroshi Okamoto
- Department of Biochemistry and Molecular Vascular Biology, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan.,Department of Biochemistry, Tohoku University, Graduate School of Medicine, Sendai, Miyagi, Japan
| | - Shigeru Yokoyama
- Department of Basic Research on Social Recognition and Memory, Research Center for Child Mental Development, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Haruhiro Higashida
- Department of Basic Research on Social Recognition and Memory, Research Center for Child Mental Development, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Yasuko Kitao
- Department of Neuroanatomy, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Osamu Hori
- Department of Neuroanatomy, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan
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519
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Plaza-Zabala A, Sierra-Torre V, Sierra A. Autophagy and Microglia: Novel Partners in Neurodegeneration and Aging. Int J Mol Sci 2017; 18:E598. [PMID: 28282924 PMCID: PMC5372614 DOI: 10.3390/ijms18030598] [Citation(s) in RCA: 217] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 02/28/2017] [Accepted: 03/05/2017] [Indexed: 02/07/2023] Open
Abstract
Autophagy is emerging as a core regulator of Central Nervous System (CNS) aging and neurodegeneration. In the brain, it has mostly been studied in neurons, where the delivery of toxic molecules and organelles to the lysosome by autophagy is crucial for neuronal health and survival. However, we propose that the (dys)regulation of autophagy in microglia also affects innate immune functions such as phagocytosis and inflammation, which in turn contribute to the pathophysiology of aging and neurodegenerative diseases. Herein, we first describe the basic concepts of autophagy and its regulation, discuss key aspects for its accurate monitoring at the experimental level, and summarize the evidence linking autophagy impairment to CNS senescence and disease. We focus on acute, chronic, and autoimmunity-mediated neurodegeneration, including ischemia/stroke, Alzheimer's, Parkinson's, and Huntington's diseases, and multiple sclerosis. Next, we describe the actual and potential impact of autophagy on microglial phagocytic and inflammatory function. Thus, we provide evidence of how autophagy may affect microglial phagocytosis of apoptotic cells, amyloid-β, synaptic material, and myelin debris, and regulate the progression of age-associated neurodegenerative diseases. We also discuss data linking autophagy to the regulation of the microglial inflammatory phenotype, which is known to contribute to age-related brain dysfunction. Overall, we update the current knowledge of autophagy and microglia, and highlight as yet unexplored mechanisms whereby autophagy in microglia may contribute to CNS disease and senescence.
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Affiliation(s)
| | | | - Amanda Sierra
- Achucarro Basque Center for Neuroscience, 48170 Zamudio, Spain.
- Department of Neurosciences, University of the Basque Country EHU/UPV, 48940 Leioa, Spain.
- Ikerbasque Foundation, 48013 Bilbao, Spain.
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520
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Murphy NA, Franklin RJM. Recruitment of endogenous CNS stem cells for regeneration in demyelinating disease. PROGRESS IN BRAIN RESEARCH 2017; 231:135-163. [PMID: 28554395 DOI: 10.1016/bs.pbr.2016.12.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Demyelinating diseases, such as multiple sclerosis (MS), are responsible for a significant portion of the neurological disability burden worldwide, especially in young adults. Demyelination can be followed by a spontaneous regenerative process called remyelination, in which new myelin sheaths are restored to denuded axons. However, in chronic demyelinating disease such as MS, this process becomes progressively less efficient. This chapter reviews the biology of remyelination and the rationale and strategies by which it can be enhanced therapeutically in acquired demyelinating disease.
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Affiliation(s)
- Natalia A Murphy
- Wellcome Trust-Medical Research Council Cambridge Stem Cell Institute, Cambridge, United Kingdom; University of Cambridge, Cambridge, United Kingdom
| | - Robin J M Franklin
- Wellcome Trust-Medical Research Council Cambridge Stem Cell Institute, Cambridge, United Kingdom; University of Cambridge, Cambridge, United Kingdom.
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521
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Boghdadi AG, Teo L, Bourne JA. The Involvement of the Myelin-Associated Inhibitors and Their Receptors in CNS Plasticity and Injury. Mol Neurobiol 2017; 55:1831-1846. [PMID: 28229330 DOI: 10.1007/s12035-017-0433-6] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Accepted: 01/31/2017] [Indexed: 12/21/2022]
Abstract
The limited capacity for the central nervous system (CNS) to repair itself was first described over 100 years ago by Spanish neuroscientist Ramon Y. Cajal. However, the exact mechanisms underlying this failure in neuronal regeneration remain unclear and, as such, no effective therapeutics yet exist. Numerous studies have attempted to elucidate the biochemical and molecular mechanisms that inhibit neuronal repair with increasing evidence suggesting that several inhibitory factors and repulsive guidance cues active during development actually persist into adulthood and may be contributing to the inhibition of repair. For example, in the injured adult CNS, there are various inhibitory factors that impede the outgrowth of neurites from damaged neurons. One of the most potent of these neurite outgrowth inhibitors is the group of proteins known as the myelin-associated inhibitors (MAIs), present mainly on the membranes of oligodendroglia. Several studies have shown that interfering with these proteins can have positive outcomes in CNS injury models by promoting neurite outgrowth and improving functional recovery. As such, the MAIs, their receptors, and downstream effectors are valid drug targets for the treatment of CNS injury. This review will discuss the current literature on MAIs in the context of CNS development, plasticity, and injury. Molecules that interfere with the MAIs and their receptors as potential candidates for the treatment of CNS injury will additionally be introduced in the context of preclinical and clinical trials.
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Affiliation(s)
- Anthony G Boghdadi
- Australian Regenerative Medicine Institute, Monash University, 15 Innovation Walk (Building 75), Clayton, VIC, 3800, Australia
| | - Leon Teo
- Australian Regenerative Medicine Institute, Monash University, 15 Innovation Walk (Building 75), Clayton, VIC, 3800, Australia
| | - James A Bourne
- Australian Regenerative Medicine Institute, Monash University, 15 Innovation Walk (Building 75), Clayton, VIC, 3800, Australia.
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522
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Yamashita T, Miyamoto Y, Bando Y, Ono T, Kobayashi S, Doi A, Araki T, Kato Y, Shirakawa T, Suzuki Y, Yamauchi J, Yoshida S, Sato N. Differentiation of oligodendrocyte progenitor cells from dissociated monolayer and feeder-free cultured pluripotent stem cells. PLoS One 2017; 12:e0171947. [PMID: 28192470 PMCID: PMC5305255 DOI: 10.1371/journal.pone.0171947] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Accepted: 01/27/2017] [Indexed: 01/11/2023] Open
Abstract
Oligodendrocytes myelinate axons and form myelin sheaths in the central nervous system. The development of therapies for demyelinating diseases, including multiple sclerosis and leukodystrophies, is a challenge because the pathogenic mechanisms of disease remain poorly understood. Primate pluripotent stem cell-derived oligodendrocytes are expected to help elucidate the molecular pathogenesis of these diseases. Oligodendrocytes have been successfully differentiated from human pluripotent stem cells. However, it is challenging to prepare large amounts of oligodendrocytes over a short amount of time because of manipulation difficulties under conventional primate pluripotent stem cell culture methods. We developed a proprietary dissociated monolayer and feeder-free culture system to handle pluripotent stem cell cultures. Because the dissociated monolayer and feeder-free culture system improves the quality and growth of primate pluripotent stem cells, these cells could potentially be differentiated into any desired functional cells and consistently cultured in large-scale conditions. In the current study, oligodendrocyte progenitor cells and mature oligodendrocytes were generated within three months from monkey embryonic stem cells. The embryonic stem cell-derived oligodendrocytes exhibited in vitro myelinogenic potency with rat dorsal root ganglion neurons. Additionally, the transplanted oligodendrocyte progenitor cells differentiated into myelin basic protein-positive mature oligodendrocytes in the mouse corpus callosum. This preparative method was used for human induced pluripotent stem cells, which were also successfully differentiated into oligodendrocyte progenitor cells and mature oligodendrocytes that were capable of myelinating rat dorsal root ganglion neurons. Moreover, it was possible to freeze, thaw, and successfully re-culture the differentiating cells. These results showed that embryonic stem cells and human induced pluripotent stem cells maintained in a dissociated monolayer and feeder-free culture system have the potential to generate oligodendrocyte progenitor cells and mature oligodendrocytes in vitro and in vivo. This culture method could be applied to prepare large amounts of oligodendrocyte progenitor cells and mature oligodendrocytes in a relatively short amount of time.
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Affiliation(s)
- Tomoko Yamashita
- Discovery Research Laboratories, Research Division, Mitsubishi Tanabe Pharma Corporation, Yokohama, Kanagawa, Japan
- * E-mail:
| | - Yuki Miyamoto
- Department of Pharmacology, National Research Institute for Child Health and Development, Setagaya, Tokyo, Japan
| | - Yoshio Bando
- Department of Functional Anatomy and Neuroscience, Asahikawa Medical University, Asahikawa, Hokkaido, Japan
| | - Takashi Ono
- Discovery Research Laboratories, Research Division, Mitsubishi Tanabe Pharma Corporation, Yokohama, Kanagawa, Japan
| | - Sakurako Kobayashi
- Discovery Research Laboratories, Research Division, Mitsubishi Tanabe Pharma Corporation, Yokohama, Kanagawa, Japan
| | - Ayano Doi
- Discovery Research Laboratories, Research Division, Mitsubishi Tanabe Pharma Corporation, Yokohama, Kanagawa, Japan
| | - Toshihiro Araki
- Discovery Research Laboratories, Research Division, Mitsubishi Tanabe Pharma Corporation, Yokohama, Kanagawa, Japan
| | - Yosuke Kato
- Discovery Research Laboratories, Research Division, Mitsubishi Tanabe Pharma Corporation, Yokohama, Kanagawa, Japan
| | - Takayuki Shirakawa
- Discovery Research Laboratories, Research Division, Mitsubishi Tanabe Pharma Corporation, Yokohama, Kanagawa, Japan
| | - Yutaka Suzuki
- Discovery Research Laboratories, Research Division, Mitsubishi Tanabe Pharma Corporation, Yokohama, Kanagawa, Japan
| | - Junji Yamauchi
- Department of Pharmacology, National Research Institute for Child Health and Development, Setagaya, Tokyo, Japan
| | - Shigetaka Yoshida
- Department of Functional Anatomy and Neuroscience, Asahikawa Medical University, Asahikawa, Hokkaido, Japan
| | - Naoya Sato
- Discovery Research Laboratories, Research Division, Mitsubishi Tanabe Pharma Corporation, Yokohama, Kanagawa, Japan
- MP Healthcare Venture Management, Boston, Massachusetts, United States of America
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523
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Yoshimura T, Hayashi A, Handa-Narumi M, Yagi H, Ohno N, Koike T, Yamaguchi Y, Uchimura K, Kadomatsu K, Sedzik J, Kitamura K, Kato K, Trapp BD, Baba H, Ikenaka K. GlcNAc6ST-1 regulates sulfation of N-glycans and myelination in the peripheral nervous system. Sci Rep 2017; 7:42257. [PMID: 28186137 PMCID: PMC5301494 DOI: 10.1038/srep42257] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 01/05/2017] [Indexed: 01/09/2023] Open
Abstract
Highly specialized glial cells wrap axons with a multilayered myelin membrane in vertebrates. Myelin serves essential roles in the functioning of the nervous system. Axonal degeneration is the major cause of permanent neurological disability in primary myelin diseases. Many glycoproteins have been identified in myelin, and a lack of one myelin glycoprotein results in abnormal myelin structures in many cases. However, the roles of glycans on myelin glycoproteins remain poorly understood. Here, we report that sulfated N-glycans are involved in peripheral nervous system (PNS) myelination. PNS myelin glycoproteins contain highly abundant sulfated N-glycans. Major sulfated N-glycans were identified in both porcine and mouse PNS myelin, demonstrating that the 6-O-sulfation of N-acetylglucosamine (GlcNAc-6-O-sulfation) is highly conserved in PNS myelin between these species. P0 protein, the most abundant glycoprotein in PNS myelin and mutations in which at the glycosylation site cause Charcot-Marie-Tooth neuropathy, has abundant GlcNAc-6-O-sulfated N-glycans. Mice deficient in N-acetylglucosamine-6-O-sulfotransferase-1 (GlcNAc6ST-1) failed to synthesize sulfated N-glycans and exhibited abnormal myelination and axonal degeneration in the PNS. Taken together, this study demonstrates that GlcNAc6ST-1 modulates PNS myelination and myelinated axonal survival through the GlcNAc-6-O-sulfation of N-glycans on glycoproteins. These findings may provide novel insights into the pathogenesis of peripheral neuropathy.
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Affiliation(s)
- Takeshi Yoshimura
- Division of Neurobiology and Bioinformatics, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
- Department of Physiological Sciences, School of Life Sciences, SOKENDAI (The Graduate University for Advanced Studies), Hayama, Kanagawa 240-0193, Japan
| | - Akiko Hayashi
- Department of Molecular Neurobiology, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan
| | - Mai Handa-Narumi
- Division of Neurobiology and Bioinformatics, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
- Department of Physiological Sciences, School of Life Sciences, SOKENDAI (The Graduate University for Advanced Studies), Hayama, Kanagawa 240-0193, Japan
| | - Hirokazu Yagi
- Department of Structural Biology and Biomolecular Engineering, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Aichi 467-8603, Japan
| | - Nobuhiko Ohno
- Division of Neurobiology and Bioinformatics, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
- Department of Physiological Sciences, School of Life Sciences, SOKENDAI (The Graduate University for Advanced Studies), Hayama, Kanagawa 240-0193, Japan
| | - Takako Koike
- Division of Neurobiology and Bioinformatics, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
| | - Yoshihide Yamaguchi
- Department of Molecular Neurobiology, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan
| | - Kenji Uchimura
- Department of Biochemistry, Graduate School of Medicine, Nagoya University, Nagoya, Aichi 466-8550, Japan
| | - Kenji Kadomatsu
- Department of Biochemistry, Graduate School of Medicine, Nagoya University, Nagoya, Aichi 466-8550, Japan
| | - Jan Sedzik
- Division of Neurobiology and Bioinformatics, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
- Department of Chemical Engineering and Technology, Protein Crystallization Facility, Royal Institute of Technology, KTH, Stockholm 10044, Sweden
| | - Kunio Kitamura
- Faculty of Health and Medical Care, Saitama Medical University, Hidaka, Saitama 350-1241, Japan
| | - Koichi Kato
- Department of Structural Biology and Biomolecular Engineering, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Aichi 467-8603, Japan
- Institute for Molecular Science and Okazaki Institute for Integrative Bioscience, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
| | - Bruce D. Trapp
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Hiroko Baba
- Department of Molecular Neurobiology, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan
| | - Kazuhiro Ikenaka
- Division of Neurobiology and Bioinformatics, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
- Department of Physiological Sciences, School of Life Sciences, SOKENDAI (The Graduate University for Advanced Studies), Hayama, Kanagawa 240-0193, Japan
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524
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Snaidero N, Simons M. The logistics of myelin biogenesis in the central nervous system. Glia 2017; 65:1021-1031. [DOI: 10.1002/glia.23116] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 12/06/2016] [Accepted: 12/12/2016] [Indexed: 01/28/2023]
Affiliation(s)
- Nicolas Snaidero
- Institute of Neuronal Cell Biology, Technical University Munich; Munich 80805 Germany
| | - Mikael Simons
- Institute of Neuronal Cell Biology, Technical University Munich; Munich 80805 Germany
- German Center for Neurodegenerative Disease (DZNE); Munich 6250 Germany
- Cellular Neuroscience; Max Planck Institute of Experimental Medicine; Göttingen 37075 Germany
- Munich Cluster for Systems Neurology (SyNergy); Munich 81377 Germany
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525
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Two factor-based reprogramming of rodent and human fibroblasts into Schwann cells. Nat Commun 2017; 8:14088. [PMID: 28169300 PMCID: PMC5309703 DOI: 10.1038/ncomms14088] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 11/18/2016] [Indexed: 11/29/2022] Open
Abstract
Schwann cells (SCs) generate the myelin wrapping of peripheral nerve axons and are promising candidates for cell therapy. However, to date a renewable source of SCs is lacking. In this study, we show the conversion of skin fibroblasts into induced Schwann cells (iSCs) by driving the expression of two transcription factors, Sox10 and Egr2. iSCs resembled primary SCs in global gene expression profiling and PNS identity. In vitro, iSCs wrapped axons generating compact myelin sheaths with regular nodal structures. Conversely, iSCs from Twitcher mice showed a severe loss in their myelinogenic potential, demonstrating that iSCs can be an attractive system for in vitro modelling of PNS diseases. The same two factors were sufficient to convert human fibroblasts into iSCs as defined by distinctive molecular and functional traits. Generating iSCs through direct conversion of somatic cells offers opportunities for in vitro disease modelling and regenerative therapies. Schwann cells (SCs) myelinate peripheral nerve axons and offer opportunities for the treatment of injuries and demyelinating diseases but reliable and renewable sources of these cells are hard to come by. Here the authors reprogram rat, mouse and human fibroblasts into Schwann cells using two transcription factors.
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526
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Meyer K, Kaspar BK. Glia-neuron interactions in neurological diseases: Testing non-cell autonomy in a dish. Brain Res 2017; 1656:27-39. [PMID: 26778174 PMCID: PMC4939136 DOI: 10.1016/j.brainres.2015.12.051] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Revised: 12/17/2015] [Accepted: 12/22/2015] [Indexed: 12/30/2022]
Abstract
For the past century, research on neurological disorders has largely focused on the most prominently affected cell types - the neurons. However, with increasing knowledge of the diverse physiological functions of glial cells, their impact on these diseases has become more evident. Thus, many conditions appear to have more complex origins than initially thought. Since neurological pathologies are often sporadic with unknown etiology, animal models are difficult to create and might only reflect a small portion of patients in which a mutation in a gene has been identified. Therefore, reliable in vitro systems to studying these disorders are urgently needed. They might be a pre-requisite for improving our understanding of the disease mechanisms as well as for the development of potential new therapies. In this review, we will briefly summarize the function of different glial cell types in the healthy central nervous system (CNS) and outline their implication in the development or progression of neurological conditions. We will then describe different types of culture systems to model non-cell autonomous interactions in vitro and evaluate advantages and disadvantages. This article is part of a Special Issue entitled SI: Exploiting human neurons.
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Affiliation(s)
- Kathrin Meyer
- The Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
| | - Brian K Kaspar
- The Research Institute at Nationwide Children's Hospital, Columbus, OH, USA; Molecular, Cellular & Developmental Biology Graduate Program, The Ohio State University, Columbus, OH, USA; Department of Neuroscience, The Ohio State University, Columbus, OH, USA.
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527
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Steiger TK, Bunzeck N. Reward Dependent Invigoration Relates to Theta Oscillations and Is Predicted by Dopaminergic Midbrain Integrity in Healthy Elderly. Front Aging Neurosci 2017; 9:1. [PMID: 28174533 PMCID: PMC5258705 DOI: 10.3389/fnagi.2017.00001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Accepted: 01/03/2017] [Indexed: 11/13/2022] Open
Abstract
Motivation can have invigorating effects on behavior via dopaminergic neuromodulation. While this relationship has mainly been established in theoretical models and studies in younger subjects, the impact of structural declines of the dopaminergic system during healthy aging remains unclear. To investigate this issue, we used electroencephalography (EEG) in healthy young and elderly humans in a reward-learning paradigm. Specifically, scene images were initially encoded by combining them with cues predicting monetary reward (high vs. low reward). Subsequently, recognition memory for the scenes was tested. As a main finding, we can show that response times (RTs) during encoding were faster for high reward predicting images in the young but not elderly participants. This pattern was resembled in power changes in the theta-band (4–7 Hz). Importantly, analyses of structural MRI data revealed that individual reward-related differences in the elderlies’ response time could be predicted by the structural integrity of the dopaminergic substantia nigra (SN; as measured by magnetization transfer (MT)). These findings suggest a close relationship between reward-based invigoration, theta oscillations and age-dependent changes of the dopaminergic system.
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Affiliation(s)
- Tineke K Steiger
- Institute for Psychology, University of LuebeckLuebeck, Germany; Department of Systems Neuroscience, University Medical Center Hamburg-EppendorfHamburg, Germany
| | - Nico Bunzeck
- Institute for Psychology, University of LuebeckLuebeck, Germany; Department of Systems Neuroscience, University Medical Center Hamburg-EppendorfHamburg, Germany
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528
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Partial Immunoblotting of 2D-Gels: A Novel Method to Identify Post-Translationally Modified Proteins Exemplified for the Myelin Acetylome. Proteomes 2017; 5:proteomes5010003. [PMID: 28248254 PMCID: PMC5372224 DOI: 10.3390/proteomes5010003] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 12/23/2016] [Accepted: 01/04/2017] [Indexed: 11/17/2022] Open
Abstract
Post-translational modifications (PTMs) play a key role in regulating protein function, yet their identification is technically demanding. Here, we present a straightforward workflow to systematically identify post-translationally modified proteins based on two-dimensional gel electrophoresis. Upon colloidal Coomassie staining the proteins are partially transferred, and the investigated PTMs are immunodetected. This strategy allows tracking back the immunopositive antigens to the corresponding spots on the original gel, from which they are excised and mass spectrometrically identified. Candidate proteins are validated on the same membrane by immunodetection using a second fluorescence channel. We exemplify the power of partial immunoblotting with the identification of lysine-acetylated proteins in myelin, the oligodendroglial membrane that insulates neuronal axons. The excellent consistency of the detected fluorescence signals at all levels allows the differential comparison of PTMs across multiple conditions. Beyond PTM screening, our multi-level workflow can be readily adapted to clinical applications such as identifying auto-immune antigens or host-pathogen interactions.
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529
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Mehta P, Piao X. Adhesion G-protein coupled receptors and extracellular matrix proteins: Roles in myelination and glial cell development. Dev Dyn 2017; 246:275-284. [PMID: 27859941 DOI: 10.1002/dvdy.24473] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 11/08/2016] [Accepted: 11/10/2016] [Indexed: 01/05/2023] Open
Abstract
Adhesion G protein-coupled receptors (aGPCRs) are a large family of transmembrane proteins that play important roles in many processes during development, primarily through cell-cell and cell-extracellular matrix (ECM) interactions. In the nervous system, they have been linked to the complex process of myelination, both in the central and peripheral nervous system. GPR126 is essential in Schwann cell-mediated myelination in the peripheral nervous system (PNS), while GPR56 is involved in oligodendrocyte development central nervous system (CNS) myelination. VLGR1 is another aGPCR that is associated with the expression of myelin-associated glycoprotein (MAG) which has inhibitory effects on the process of nerve repair. The ECM is composed of a vast array of structural proteins, three of which interact specifically with aGPCRs: collagen III/GPR56, collagen IV/GPR126, and laminin-211/GPR126. As druggable targets, aGPCRs are valuable in their ability to unlock treatment for a wide variety of currently debilitating myelin disorders. Developmental Dynamics 246:275-284, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Paulomi Mehta
- Division of Newborn Medicine, Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Xianhua Piao
- Division of Newborn Medicine, Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
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530
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Maki T. Novel roles of oligodendrocyte precursor cells in the developing and damaged brain. ACTA ACUST UNITED AC 2017. [DOI: 10.1111/cen3.12358] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Takakuni Maki
- Department of Neurology; Graduate School of Medicine; Kyoto University; Kyoto Japan
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531
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Volpi VG, Touvier T, D'Antonio M. Endoplasmic Reticulum Protein Quality Control Failure in Myelin Disorders. Front Mol Neurosci 2017; 9:162. [PMID: 28101003 PMCID: PMC5209374 DOI: 10.3389/fnmol.2016.00162] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 12/16/2016] [Indexed: 12/24/2022] Open
Abstract
Reaching the correct three-dimensional structure is crucial for the proper function of a protein. The endoplasmic reticulum (ER) is the organelle where secreted and transmembrane proteins are synthesized and folded. To guarantee high fidelity of protein synthesis and maturation in the ER, cells have evolved ER-protein quality control (ERQC) systems, which assist protein folding and promptly degrade aberrant gene products. Only correctly folded proteins that pass ERQC checkpoints are allowed to exit the ER and reach their final destination. Misfolded glycoproteins are detected and targeted for degradation by the proteasome in a process known as endoplasmic reticulum-associated degradation (ERAD). The excess of unstructured proteins in the ER triggers an adaptive signal transduction pathway, called unfolded protein response (UPR), which in turn potentiates ERQC activities in order to reduce the levels of aberrant molecules. When the situation cannot be restored, the UPR drives cells to apoptosis. Myelin-forming cells of the central and peripheral nervous system (oligodendrocytes and Schwann cells) synthesize a large amount of myelin proteins and lipids and therefore are particularly susceptible to ERQC failure. Indeed, deficits in ERQC and activation of ER stress/UPR have been implicated in several myelin disorders, such as Pelizaeus-Merzbacher and Krabbe leucodystrophies, vanishing white matter disease and Charcot-Marie-Tooth neuropathies. Here we discuss recent evidence underlying the importance of proper ERQC functions in genetic disorders of myelinating glia.
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Affiliation(s)
- Vera G Volpi
- Biology of Myelin Unit, Division of Genetics and Cell Biology, San Raffaele Scientific Institute, DIBIT Milan, Italy
| | - Thierry Touvier
- Biology of Myelin Unit, Division of Genetics and Cell Biology, San Raffaele Scientific Institute, DIBIT Milan, Italy
| | - Maurizio D'Antonio
- Biology of Myelin Unit, Division of Genetics and Cell Biology, San Raffaele Scientific Institute, DIBIT Milan, Italy
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532
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Cerina M, Narayanan V, Göbel K, Bittner S, Ruck T, Meuth P, Herrmann AM, Stangel M, Gudi V, Skripuletz T, Daldrup T, Wiendl H, Seidenbecher T, Ehling P, Kleinschnitz C, Pape HC, Budde T, Meuth SG. The quality of cortical network function recovery depends on localization and degree of axonal demyelination. Brain Behav Immun 2017; 59:103-117. [PMID: 27569659 DOI: 10.1016/j.bbi.2016.08.014] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2016] [Revised: 08/12/2016] [Accepted: 08/25/2016] [Indexed: 10/21/2022] Open
Abstract
Myelin loss is a severe pathological hallmark common to a number of neurodegenerative diseases, including multiple sclerosis (MS). Demyelination in the central nervous system appears in the form of lesions affecting both white and gray matter structures. The functional consequences of demyelination on neuronal network and brain function are not well understood. Current therapeutic strategies for ameliorating the course of such diseases usually focus on promoting remyelination, but the effectiveness of these approaches strongly depends on the timing in relation to the disease state. In this study, we sought to characterize the time course of sensory and behavioral alterations induced by de- and remyelination to establish a rational for the use of remyelination strategies. By taking advantage of animal models of general and focal demyelination, we tested the consequences of myelin loss on the functionality of the auditory thalamocortical system: a well-studied neuronal network consisting of both white and gray matter regions. We found that general demyelination was associated with a permanent loss of the tonotopic cortical organization in vivo, and the inability to induce tone-frequency-dependent conditioned behaviors, a status persisting after remyelination. Targeted, focal lysolecithin-induced lesions in the white matter fiber tract, but not in the gray matter regions of cortex, were fully reversible at the morphological, functional and behavioral level. These findings indicate that remyelination of white and gray matter lesions have a different functional regeneration potential, with the white matter being able to regain full functionality while cortical gray matter lesions suffer from permanently altered network function. Therefore therapeutic interventions aiming for remyelination have to consider both region- and time-dependent strategies.
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Affiliation(s)
- Manuela Cerina
- Department of Neurology, University of Münster, Münster, Germany.
| | - Venu Narayanan
- Department of Neurology, University of Münster, Münster, Germany
| | - Kerstin Göbel
- Department of Neurology, University of Münster, Münster, Germany
| | - Stefan Bittner
- Department of Neurology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Tobias Ruck
- Department of Neurology, University of Münster, Münster, Germany
| | - Patrick Meuth
- Department of Neurology, University of Münster, Münster, Germany
| | | | - Martin Stangel
- Clinical Neuroimmunology and Neurochemistry, Department of Neurology, Hannover Medical School and Centre for Systems Neuroscience, Hannover, Germany
| | - Viktoria Gudi
- Department of Neurology, Hannover Medical School, Hannover, Germany
| | | | - Thiemo Daldrup
- Institute of Physiology I, University of Münster, Münster, Germany
| | - Heinz Wiendl
- Department of Neurology, University of Münster, Münster, Germany
| | | | - Petra Ehling
- Department of Neurology, University of Münster, Münster, Germany
| | | | | | - Thomas Budde
- Institute of Physiology I, University of Münster, Münster, Germany
| | - Sven G Meuth
- Department of Neurology, University of Münster, Münster, Germany.
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533
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Ramamurthy P, White JB, Yull Park J, Hume RI, Ebisu F, Mendez F, Takayama S, Barald KF. Concomitant differentiation of a population of mouse embryonic stem cells into neuron-like cells and schwann cell-like cells in a slow-flow microfluidic device. Dev Dyn 2017; 246:7-27. [PMID: 27761977 PMCID: PMC5159187 DOI: 10.1002/dvdy.24466] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 09/16/2016] [Accepted: 09/30/2016] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND To send meaningful information to the brain, an inner ear cochlear implant (CI) must become closely coupled to as large and healthy a population of remaining spiral ganglion neurons (SGN) as possible. Inner ear gangliogenesis depends on macrophage migration inhibitory factor (MIF), a directionally attractant neurotrophic cytokine made by both Schwann and supporting cells (Bank et al., 2012). MIF-induced mouse embryonic stem cell (mESC)-derived "neurons" could potentially substitute for lost or damaged SGN. mESC-derived "Schwann cells" produce MIF, as do all Schwann cells (Huang et al., a; Roth et al., 2007; Roth et al., 2008) and could attract SGN to a "cell-coated" implant. RESULTS Neuron- and Schwann cell-like cells were produced from a common population of mESCs in an ultra-slow-flow microfluidic device. As the populations interacted, "neurons" grew over the "Schwann cell" lawn, and early events in myelination were documented. Blocking MIF on the Schwann cell side greatly reduced directional neurite outgrowth. MIF-expressing "Schwann cells" were used to coat a CI: Mouse SGN and MIF-induced "neurons" grew directionally to the CI and to a wild-type but not MIF-knockout organ of Corti explant. CONCLUSIONS Two novel stem cell-based approaches for treating the problem of sensorineural hearing loss are described. Developmental Dynamics 246:7-27, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Poornapriya Ramamurthy
- Department of Biomedical Engineering, College of Engineering, University of Michigan, Ann Arbor, Michigan
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, Michigan
| | - Joshua B White
- Department of Biomedical Engineering, College of Engineering, University of Michigan, Ann Arbor, Michigan
| | - Joong Yull Park
- School of Mechanical Engineering, College of Engineering, Chung-Ang University, Seoul, Republic of Korea
| | - Richard I Hume
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, Michigan
| | - Fumi Ebisu
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, Michigan
| | - Flor Mendez
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, Michigan
| | - Shuichi Takayama
- Department of Biomedical Engineering, College of Engineering, University of Michigan, Ann Arbor, Michigan
| | - Kate F Barald
- Department of Biomedical Engineering, College of Engineering, University of Michigan, Ann Arbor, Michigan
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, Michigan
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, Michigan
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534
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Pintado-Sierra M, García-Álvarez I, Bribián A, Medina-Rodríguez EM, Lebrón-Aguilar R, Garrido L, de Castro F, Fernández-Mayoralas A, Quintanilla-López JE. A comprehensive profiling of sulfatides in myelin from mouse brain using liquid chromatography coupled to high-resolution accurate tandem mass spectrometry. Anal Chim Acta 2016; 951:89-98. [PMID: 27998489 DOI: 10.1016/j.aca.2016.11.054] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 11/25/2016] [Accepted: 11/28/2016] [Indexed: 11/17/2022]
Abstract
Sulfatides are sulfoglycolipids found in the myelin sheath. The composition ratio of sulfatide molecular species changes with age, and it has also been associated with the pathogenesis of various human central nervous system diseases. However, profiling sulfatides in biological samples is difficult, due to the great variety of molecular species. In this work, a new, easy and reliable liquid chromatography-electrospray tandem mass spectrometry (LC-ESI(+)-MS/MS) method has been developed to profile sulfatide content in biological samples of myelin. The 'wrong-way-round' ionization effect has been described for this type of molecules for the first time, making it possible to correctly identify as many as 37 different sulfatides in mouse brain myelin samples, including molecules with different fatty acid chain lengths and varying degrees of unsaturation and hydroxylation. A chemometric analysis of their relative abundances showed that the main difference among individuals of different ages was the content of sulfatides with odd-numbered fatty acid chains, in addition to hydroxylated species.
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Affiliation(s)
- M Pintado-Sierra
- Instituto de Química Orgánica General (CSIC), Juan de la Cierva 3, 28006, Madrid, Spain
| | - I García-Álvarez
- Instituto de Química Orgánica General (CSIC), Juan de la Cierva 3, 28006, Madrid, Spain; Grupo de Neurobiología del Desarrollo-GNDe, Hospital Nacional de Parapléjicos, Finca "La Peraleda", 45071, Toledo, Spain
| | - A Bribián
- Grupo de Neurobiología del Desarrollo-GNDe, Hospital Nacional de Parapléjicos, Finca "La Peraleda", 45071, Toledo, Spain; Grupo de Neurobiología del Desarrollo-GNDe, Instituto Cajal (CSIC), Doctor Arce 37, 28002, Madrid, Spain
| | - E M Medina-Rodríguez
- Grupo de Neurobiología del Desarrollo-GNDe, Hospital Nacional de Parapléjicos, Finca "La Peraleda", 45071, Toledo, Spain
| | - R Lebrón-Aguilar
- Instituto de Química-Física 'Rocasolano' (CSIC), Serrano 119, 28006, Madrid, Spain
| | - L Garrido
- Instituto de Ciencia y Tecnología de Polímeros (CSIC), Juan de la Cierva 3, 28006, Madrid, Spain
| | - F de Castro
- Grupo de Neurobiología del Desarrollo-GNDe, Hospital Nacional de Parapléjicos, Finca "La Peraleda", 45071, Toledo, Spain; Grupo de Neurobiología del Desarrollo-GNDe, Instituto Cajal (CSIC), Doctor Arce 37, 28002, Madrid, Spain
| | - A Fernández-Mayoralas
- Instituto de Química Orgánica General (CSIC), Juan de la Cierva 3, 28006, Madrid, Spain
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535
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Ornelas IM, McLane LE, Saliu A, Evangelou AV, Khandker L, Wood TL. Heterogeneity in oligodendroglia: Is it relevant to mouse models and human disease? J Neurosci Res 2016; 94:1421-1433. [PMID: 27557736 PMCID: PMC5513674 DOI: 10.1002/jnr.23900] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2016] [Revised: 07/29/2016] [Accepted: 08/04/2016] [Indexed: 01/09/2023]
Abstract
There are many lines of evidence indicating that oligodendrocyte progenitor cells and oligodendrocyte populations in the central nervous system (CNS) are heterogeneous based on their developmental origins as well as from morphological and molecular criteria. Whether these distinctions reflect functional heterogeneity is less clear and has been the subject of considerable debate. Recent findings, particularly from knockout mouse models, have provided new evidence for regional variations in myelination phenotypes, particularly between brain and spinal cord. These data raise the possibility that oligodendrocytes in these regions have different functional capacities and/or ability to compensate for loss of a specific gene. The goal of this review is to briefly revisit the evidence for oligodendrocyte heterogeneity and then to present data from transgenic and demyelinating mouse models suggesting functional heterogeneity in myelination, demyelination, and remyelination in the CNS and, finally, to discuss the implications of these findings for human diseases. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Isis M Ornelas
- Department of Pharmacology, Physiology & Neuroscience, New Jersey Medical School, Rutgers University, Newark, New Jersey
| | - Lauren E McLane
- Department of Pharmacology, Physiology & Neuroscience, New Jersey Medical School, Rutgers University, Newark, New Jersey
| | - Aminat Saliu
- Department of Pharmacology, Physiology & Neuroscience, New Jersey Medical School, Rutgers University, Newark, New Jersey
| | - Angelina V Evangelou
- Department of Pharmacology, Physiology & Neuroscience, New Jersey Medical School, Rutgers University, Newark, New Jersey
| | - Luipa Khandker
- Department of Pharmacology, Physiology & Neuroscience, New Jersey Medical School, Rutgers University, Newark, New Jersey
| | - Teresa L Wood
- Department of Pharmacology, Physiology & Neuroscience, New Jersey Medical School, Rutgers University, Newark, New Jersey.
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536
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Ichihara Y, Doi T, Ryu Y, Nagao M, Sawada Y, Ogata T. Oligodendrocyte Progenitor Cells Directly Utilize Lactate for Promoting Cell Cycling and Differentiation. J Cell Physiol 2016; 232:986-995. [PMID: 27861886 PMCID: PMC5299506 DOI: 10.1002/jcp.25690] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 11/11/2016] [Indexed: 12/17/2022]
Abstract
Oligodendrocyte progenitor cells (OPCs) undergo marked morphological changes to become mature oligodendrocytes, but the metabolic resources for this process have not been fully elucidated. Although lactate, a metabolic derivative of glycogen, has been reported to be consumed in oligodendrocytes as a metabolite, and to ameliorate hypomyelination induced by low glucose conditions, it is not clear about the direct contribution of lactate to cell cycling and differentiation of OPCs, and the source of lactate for remyelination. Therefore, we evaluated the effect of 1,4‐dideoxy‐1,4‐imino‐d‐arabinitol (DAB), an inhibitor of the glycogen catabolic enzyme glycogen phosphorylase, in a mouse cuprizone model. Cuprizone induced demyelination in the corpus callosum and remyelination occurred after cuprizone treatment ceased. This remyelination was inhibited by the administration of DAB. To further examine whether lactate affects proliferation or differentiation of OPCs, we cultured mouse primary OPC‐rich cells and analyzed the effect of lactate. Lactate rescued the slowed cell cycling induced by 0.4 mM glucose, as assessed by the BrdU‐positive cell ratio. Lactate also promoted OPC differentiation detected by monitoring the mature oligodendrocyte marker myelin basic protein, in the presence of both 36.6 mM and 0.4 mM glucose. Furthermore, these lactate‐mediated effects were suppressed by the reported monocarboxylate transporter inhibitor, α‐cyano‐4‐hydroxy‐cinnamate. These results suggest that lactate directly promotes the cell cycling rate and differentiation of OPCs, and that glycogen, one of the sources of lactate, contributes to remyelination in vivo. J. Cell. Physiol. 232: 986–995, 2017. © 2016 The Authors. Journal of Cellular Physiology Published by Wiley Periodicals, Inc.
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Affiliation(s)
- Yoshinori Ichihara
- Department of Rehabilitation for Movement Functions, National Rehabilitation Center for Persons With Disabilities, Saitama, Japan
| | - Toru Doi
- Department of Rehabilitation for Movement Functions, National Rehabilitation Center for Persons With Disabilities, Saitama, Japan
| | - Youngjae Ryu
- Department of Rehabilitation for Movement Functions, National Rehabilitation Center for Persons With Disabilities, Saitama, Japan
| | - Motoshi Nagao
- Department of Rehabilitation for Movement Functions, National Rehabilitation Center for Persons With Disabilities, Saitama, Japan
| | - Yasuhiro Sawada
- Department of Rehabilitation for Movement Functions, National Rehabilitation Center for Persons With Disabilities, Saitama, Japan
| | - Toru Ogata
- Department of Rehabilitation for Movement Functions, National Rehabilitation Center for Persons With Disabilities, Saitama, Japan
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537
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Zhu H, Chen L, Yang Y, Zhu Z, Zhang X, Li W, Miao L, Zhang Y, Ou G. The glial actin cytoskeleton regulates neuronal ciliogenesis. Cell Res 2016; 27:448-451. [PMID: 27834345 DOI: 10.1038/cr.2016.131] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Affiliation(s)
- Hao Zhu
- Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Lianwan Chen
- Institute of Biophysics, Chinese Academy of Sciences, Beijing 100081, China
| | - Yihong Yang
- Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Zhiwen Zhu
- Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Xianliang Zhang
- Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Wei Li
- Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Long Miao
- Institute of Biophysics, Chinese Academy of Sciences, Beijing 100081, China
| | - Yan Zhang
- Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Guangshuo Ou
- Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
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538
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Wood TC, Simmons C, Hurley SA, Vernon AC, Torres J, Dell’Acqua F, Williams SC, Cash D. Whole-brain ex-vivo quantitative MRI of the cuprizone mouse model. PeerJ 2016; 4:e2632. [PMID: 27833805 PMCID: PMC5101606 DOI: 10.7717/peerj.2632] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Accepted: 09/29/2016] [Indexed: 11/20/2022] Open
Abstract
Myelin is a critical component of the nervous system and a major contributor to contrast in Magnetic Resonance (MR) images. However, the precise contribution of myelination to multiple MR modalities is still under debate. The cuprizone mouse is a well-established model of demyelination that has been used in several MR studies, but these have often imaged only a single slice and analysed a small region of interest in the corpus callosum. We imaged and analyzed the whole brain of the cuprizone mouse ex-vivo using high-resolution quantitative MR methods (multi-component relaxometry, Diffusion Tensor Imaging (DTI) and morphometry) and found changes in multiple regions, including the corpus callosum, cerebellum, thalamus and hippocampus. The presence of inflammation, confirmed with histology, presents difficulties in isolating the sensitivity and specificity of these MR methods to demyelination using this model.
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Affiliation(s)
- Tobias C. Wood
- Department of Neuroimaging, IOPPN, King’s College London, London, United Kingdom
| | - Camilla Simmons
- Department of Neuroimaging, IOPPN, King’s College London, London, United Kingdom
| | - Samuel A. Hurley
- FMRIB Centre, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, Oxfordshire, United Kingdom
- Synaptive Medical, Toronto, ON, Canada
| | - Anthony C. Vernon
- Cells and Behaviour Unit, Department of Basic and Clinical Neuroscience, IOPPN, King’s College London, London, United Kingdom
| | - Joel Torres
- Department of Neuroimaging, IOPPN, King’s College London, London, United Kingdom
| | - Flavio Dell’Acqua
- Department of Neuroimaging, IOPPN, King’s College London, London, United Kingdom
- NatBrainLab, Department of Basic and Clinical Neuroscience, IOPPN, King’s College London, London, United Kingdom
| | - Steve C.R. Williams
- Department of Neuroimaging, IOPPN, King’s College London, London, United Kingdom
| | - Diana Cash
- Department of Neuroimaging, IOPPN, King’s College London, London, United Kingdom
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539
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Yin F, Sancheti H, Patil I, Cadenas E. Energy metabolism and inflammation in brain aging and Alzheimer's disease. Free Radic Biol Med 2016; 100:108-122. [PMID: 27154981 PMCID: PMC5094909 DOI: 10.1016/j.freeradbiomed.2016.04.200] [Citation(s) in RCA: 312] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Revised: 04/07/2016] [Accepted: 04/29/2016] [Indexed: 02/07/2023]
Abstract
The high energy demand of the brain renders it sensitive to changes in energy fuel supply and mitochondrial function. Deficits in glucose availability and mitochondrial function are well-known hallmarks of brain aging and are particularly accentuated in neurodegenerative disorders such as Alzheimer's disease. As important cellular sources of H2O2, mitochondrial dysfunction is usually associated with altered redox status. Bioenergetic deficits and chronic oxidative stress are both major contributors to cognitive decline associated with brain aging and Alzheimer's disease. Neuroinflammatory changes, including microglial activation and production of inflammatory cytokines, are observed in neurodegenerative diseases and normal aging. The bioenergetic hypothesis advocates for sequential events from metabolic deficits to propagation of neuronal dysfunction, to aging, and to neurodegeneration, while the inflammatory hypothesis supports microglia activation as the driving force for neuroinflammation. Nevertheless, growing evidence suggests that these diverse mechanisms have redox dysregulation as a common denominator and connector. An independent view of the mechanisms underlying brain aging and neurodegeneration is being replaced by one that entails multiple mechanisms coordinating and interacting with each other. This review focuses on the alterations in energy metabolism and inflammatory responses and their connection via redox regulation in normal brain aging and Alzheimer's disease. Interaction of these systems is reviewed based on basic research and clinical studies.
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Affiliation(s)
- Fei Yin
- Pharmacology & Pharmaceutical Sciences, School of Pharmacy, University of Southern California, 1985 Zonal Avenue Los Angeles, CA 90089 9121, USA.
| | - Harsh Sancheti
- Pharmacology & Pharmaceutical Sciences, School of Pharmacy, University of Southern California, 1985 Zonal Avenue Los Angeles, CA 90089 9121, USA
| | - Ishan Patil
- Pharmacology & Pharmaceutical Sciences, School of Pharmacy, University of Southern California, 1985 Zonal Avenue Los Angeles, CA 90089 9121, USA
| | - Enrique Cadenas
- Pharmacology & Pharmaceutical Sciences, School of Pharmacy, University of Southern California, 1985 Zonal Avenue Los Angeles, CA 90089 9121, USA
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540
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Sroka IC, Chopra H, Das L, Gard JMC, Nagle RB, Cress AE. Schwann Cells Increase Prostate and Pancreatic Tumor Cell Invasion Using Laminin Binding A6 Integrin. J Cell Biochem 2016; 117:491-9. [PMID: 26239765 DOI: 10.1002/jcb.25300] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Accepted: 07/31/2015] [Indexed: 01/13/2023]
Abstract
Human pancreatic and prostate cancers metastasize along nerve axons during perineural invasion. The extracellular matrix laminin class of proteins is an abundant component of both myelinated and non-myelinated nerves. Analysis of human pancreatic and prostate tissue revealed both perineural and endoneural invasion with Schwann cells surrounded or disrupted by tumor, respectively. Tumor and nerve cell co-culture conditions were used to determine if myelinating or non-myelinating Schwann cell (S16 and S16Y, respectively) phenotype was equally likely to promote integrin-dependent cancer cell invasion and migration on laminin. Conditioned medium from S16 cells increased tumor cell (DU145, PC3, and CFPAC1) invasion into laminin approximately 1.3-2.0 fold compared to fetal bovine serum (FBS) treated cells. Integrin function (e.g., ITGA6p formation) increased up to 1.5 fold in prostate (DU145, PC3, RWPE-1) and pancreatic (CFPAC1) cells, and invasion was dependent on ITGA6p formation and ITGB1 as determined by function-blocking antibodies. In contrast, conditioned medium isolated from S16Y cells (non-myelinating phenotype) decreased constitutive levels of ITGA6p in the tumor cells by 50% compared to untreated cells and decreased ITGA6p formation 3.0 fold compared to S16 treated cells. Flow cytometry and western blot analysis revealed loss of ITGA6p formation as reversible and independent of overall loss of ITGA6 expression. These results suggest that the myelinating phenotype of Schwann cells within the tumor microenvironment increased integrin-dependent tumor invasion on laminin.
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Affiliation(s)
- Isis C Sroka
- Department of Pharmacology, University of Arizona College of Medicine, Tucson, Arizona, 85724
| | - Harsharon Chopra
- Department of Pathology, University of Arizona College of Medicine, Tucson, Arizona, 85724
| | - Lipsa Das
- University of Arizona Cancer Center, 1515 North Campbell Avenue, Tucson, Arizona, 85724
| | - Jaime M C Gard
- University of Arizona Cancer Center, 1515 North Campbell Avenue, Tucson, Arizona, 85724
| | - Raymond B Nagle
- Department of Pathology, University of Arizona College of Medicine, Tucson, Arizona, 85724
| | - Anne E Cress
- University of Arizona Cancer Center, 1515 North Campbell Avenue, Tucson, Arizona, 85724.,Department of Cellular and Molecular Medicine, University of Arizona College of Medicine, Tucson, Arizona, 85724
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541
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van Velthoven CT, Dzietko M, Wendland MF, Derugin N, Faustino J, Heijnen CJ, Ferriero DM, Vexler ZS. Mesenchymal stem cells attenuate MRI-identifiable injury, protect white matter, and improve long-term functional outcomes after neonatal focal stroke in rats. J Neurosci Res 2016; 95:1225-1236. [PMID: 27781299 DOI: 10.1002/jnr.23954] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Revised: 08/01/2016] [Accepted: 09/07/2016] [Indexed: 12/30/2022]
Abstract
Cell therapy has emerged as a potential treatment for many neurodegenerative diseases including stroke and neonatal ischemic brain injury. Delayed intranasal administration of mesenchymal stem cells (MSCs) after experimental hypoxia-ischemia and after a transient middle cerebral artery occlusion (tMCAO) in neonatal rats has shown improvement in long-term functional outcomes, but the effects of MSCs on white matter injury (WMI) are insufficiently understood. In this study we used longitudinal T2-weighted (T2W) and diffusion tensor magnetic resonance imaging (MRI) to characterize chronic injury after tMCAO induced in postnatal day 10 (P10) rats and examined the effects of delayed MSC administration on WMI, axonal coverage, and long-term somatosensory function. We show unilateral injury- and region-dependent changes in diffusion fraction anisotropy 1 and 2 weeks after tMCAO that correspond to accumulation of degraded myelin basic protein, astrocytosis, and decreased axonal coverage. With the use of stringent T2W-based injury criteria at 72 hr after tMCAO to randomize neonatal rats to receive intranasal MSCs or vehicle, we show that a single MSC administration attenuates WMI and enhances somatosensory function 28 days after stroke. A positive correlation was found between MSC-enhanced white matter integrity and functional performance in injured neonatal rats. Collectively, these data indicate that the damage induced by tMCAO progresses over time and is halted by administration of MSCs. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Cindy T van Velthoven
- Department of Neurology, University of California, San Francisco, San Francisco, California
| | - Mark Dzietko
- Department of Neurology, University of California, San Francisco, San Francisco, California
| | - Michael F Wendland
- Department of Neurology, University of California, San Francisco, San Francisco, California
| | - Nikita Derugin
- Department of Neurology, University of California, San Francisco, San Francisco, California
| | - Joel Faustino
- Department of Neurology, University of California, San Francisco, San Francisco, California
| | - Cobi J Heijnen
- Laboratory of Neuroimmunology, Division of Internal Medicine, University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Donna M Ferriero
- Department of Neurology, University of California, San Francisco, San Francisco, California.,Department of Pediatrics, University of California, San Francisco, San Francisco, California
| | - Zinaida S Vexler
- Department of Neurology, University of California, San Francisco, San Francisco, California
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542
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Griggs RB, Yermakov LM, Susuki K. Formation and disruption of functional domains in myelinated CNS axons. Neurosci Res 2016; 116:77-87. [PMID: 27717670 DOI: 10.1016/j.neures.2016.09.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 09/19/2016] [Accepted: 09/23/2016] [Indexed: 12/15/2022]
Abstract
Communication in the central nervous system (CNS) occurs through initiation and propagation of action potentials at excitable domains along axons. Action potentials generated at the axon initial segment (AIS) are regenerated at nodes of Ranvier through the process of saltatory conduction. Proper formation and maintenance of the molecular structure at the AIS and nodes are required for sustaining conduction fidelity. In myelinated CNS axons, paranodal junctions between the axolemma and myelinating oligodendrocytes delineate nodes of Ranvier and regulate the distribution and localization of specialized functional elements, such as voltage-gated sodium channels and mitochondria. Disruption of excitable domains and altered distribution of functional elements in CNS axons is associated with demyelinating diseases such as multiple sclerosis, and is likely a mechanism common to other neurological disorders. This review will provide a brief overview of the molecular structure of the AIS and nodes of Ranvier, as well as the distribution of mitochondria in myelinated axons. In addition, this review highlights important structural and functional changes within myelinated CNS axons that are associated with neurological dysfunction.
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Affiliation(s)
- Ryan B Griggs
- Department of Neuroscience, Cell Biology, and Physiology, Boonshoft School of Medicine, Wright State University, Dayton, OH, United States
| | - Leonid M Yermakov
- Department of Neuroscience, Cell Biology, and Physiology, Boonshoft School of Medicine, Wright State University, Dayton, OH, United States
| | - Keiichiro Susuki
- Department of Neuroscience, Cell Biology, and Physiology, Boonshoft School of Medicine, Wright State University, Dayton, OH, United States.
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543
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Yamazaki R, Ishibashi T, Baba H, Yamaguchi Y. Knockdown of Unconventional Myosin ID Expression Induced Morphological Change in Oligodendrocytes. ASN Neuro 2016; 8:1759091416669609. [PMID: 27655972 PMCID: PMC5036140 DOI: 10.1177/1759091416669609] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 08/05/2016] [Accepted: 08/22/2016] [Indexed: 11/19/2022] Open
Abstract
Myelin is a special multilamellar structure involved in various functions in the nervous system. In the central nervous system, the oligodendrocyte (OL) produces myelin and has a unique morphology. OLs have a dynamic membrane sorting system associated with cytoskeletal organization, which aids in the production of myelin. Recently, it was reported that the assembly and disassembly of actin filaments is crucial for myelination. However, the partner myosin molecule which associates with actin filaments during the myelination process has not yet been identified. One candidate myosin is unconventional myosin ID (Myo1d) which is distributed throughout central nervous system myelin; however, its function is still unclear. We report here that Myo1d is expressed during later stages of OL differentiation, together with myelin proteolipid protein (PLP). In addition, Myo1d is distributed at the leading edge of the myelin-like membrane in cultured OL, colocalizing mainly with actin filaments, 2',3'-cyclic nucleotide phosphodiesterase and partially with PLP. Myo1d-knockdown with specific siRNA induces significant morphological changes such as the retraction of processes and degeneration of myelin-like membrane, and finally apoptosis. Furthermore, loss of Myo1d by siRNA results in the impairment of intracellular PLP transport. Together, these results suggest that Myo1d may contribute to membrane dynamics either in wrapping or transporting of myelin membrane proteins during formation and maintenance of myelin.
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Affiliation(s)
- Reiji Yamazaki
- Department of Molecular Neurobiology, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, Japan
| | - Tomoko Ishibashi
- Department of Molecular Neurobiology, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, Japan
| | - Hiroko Baba
- Department of Molecular Neurobiology, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, Japan
| | - Yoshihide Yamaguchi
- Department of Molecular Neurobiology, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, Japan
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544
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Cercignani M, Giulietti G, Dowell NG, Gabel M, Broad R, Leigh PN, Harrison NA, Bozzali M. Characterizing axonal myelination within the healthy population: a tract-by-tract mapping of effects of age and gender on the fiber g-ratio. Neurobiol Aging 2016; 49:109-118. [PMID: 27792897 PMCID: PMC5156474 DOI: 10.1016/j.neurobiolaging.2016.09.016] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Revised: 09/22/2016] [Accepted: 09/22/2016] [Indexed: 11/21/2022]
Abstract
The g-ratio, equal to the ratio of the inner-to-outer diameter of a myelinated axon, is associated with the speed of conduction, and thus reflects axonal function and integrity. It is now possible to estimate an “aggregate” g-ratio in vivo using MRI. The aim of this study was to assess the variation of the MRI-derived fiber g-ratio in the brain of healthy individuals, and to characterize its variation across the lifespan. Thirty-eight healthy participants, aged between 20 and 76, were recruited. Whole-brain g-ratio maps were computed and analyzed voxel-wise. Median tract g-ratio values were also extracted. No significant effect of gender was found, whereas age was found to be significantly associated with the g-ratio within the white matter. The tract-specific analysis showed this relationship to follow a nearly-linear increase, although the slope appears to slow down slightly after the 6th decade of life. The most likely interpretation is a subtle but consistent reduction in myelin throughout adulthood, with the density of axons beginning to decrease between the 4th and 5th decade.
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Affiliation(s)
- Mara Cercignani
- Department of Neuroscience, Clinical Imaging Sciences Centre, Brighton and Sussex Medical School, University of Sussex, Brighton, East Sussex, UK; Neuroimaging Laboratory, Santa Lucia Foundation, Rome, Italy.
| | | | - Nick G Dowell
- Department of Neuroscience, Clinical Imaging Sciences Centre, Brighton and Sussex Medical School, University of Sussex, Brighton, East Sussex, UK
| | - Matt Gabel
- Department of Neuroscience, Clinical Imaging Sciences Centre, Brighton and Sussex Medical School, University of Sussex, Brighton, East Sussex, UK
| | - Rebecca Broad
- Neuroimaging Laboratory, Santa Lucia Foundation, Rome, Italy
| | - P Nigel Leigh
- Neuroimaging Laboratory, Santa Lucia Foundation, Rome, Italy
| | - Neil A Harrison
- Department of Neuroscience, Clinical Imaging Sciences Centre, Brighton and Sussex Medical School, University of Sussex, Brighton, East Sussex, UK
| | - Marco Bozzali
- Neuroimaging Laboratory, Santa Lucia Foundation, Rome, Italy
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545
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Akt Regulates Axon Wrapping and Myelin Sheath Thickness in the PNS. J Neurosci 2016; 36:4506-21. [PMID: 27098694 DOI: 10.1523/jneurosci.3521-15.2016] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 03/02/2016] [Indexed: 12/23/2022] Open
Abstract
UNLABELLED The signaling pathways that regulate myelination in the PNS remain poorly understood. Phosphatidylinositol-4,5-bisphosphate 3-kinase 1A, activated in Schwann cells by neuregulin and the extracellular matrix, has an essential role in the early events of myelination. Akt/PKB, a key effector of phosphatidylinositol-4,5-bisphosphate 3-kinase 1A, was previously implicated in CNS, but not PNS myelination. Here we demonstrate that Akt plays a crucial role in axon ensheathment and in the regulation of myelin sheath thickness in the PNS. Pharmacological inhibition of Akt in DRG neuron-Schwann cell cocultures dramatically decreased MBP and P0 levels and myelin sheath formation without affecting expression of Krox20/Egr2, a key transcriptional regulator of myelination. Conversely, expression of an activated form of Akt in purified Schwann cells increased expression of myelin proteins, but not Krox20/Egr2, and the levels of activated Rac1. Transgenic mice expressing a membrane-targeted, activated form of Akt under control of the 2',3'-cyclic nucleotide 3'-phosphodiesterase promoter, exhibited thicker PNS and CNS myelin sheaths, and PNS myelin abnormalities, such as tomacula and myelin infoldings/outfoldings, centered around the paranodes and Schmidt Lanterman incisures. These effects were corrected by rapamycin treatmentin vivo Importantly, Akt activity in the transgenic mice did not induce myelination of nonmyelinating Schwann cells in the sympathetic trunk or Remak fibers of the dorsal roots, although, in those structures, they wrapped membranes redundantly around axons. Together, our data indicate that Akt is crucial for PNS myelination driving axonal wrapping by unmyelinated and myelinated Schwann cells and enhancing myelin protein synthesis in myelinating Schwann cells. SIGNIFICANCE STATEMENT Although the role of the key serine/threonine kinase Akt in promoting CNS myelination has been demonstrated, its role in the PNS has not been established and remains uncertain. This work reveals that Akt controls several key steps of the PNS myelination. First, its activity promotes membrane production and axonal wrapping independent of a transcriptional effect. In myelinated axons, it also enhances myelin thickness through the mTOR pathway. Finally, sustained Akt activation in Schwann cells leads to hypermyelination/dysmyelination, mimicking some features present in neuropathies, such as hereditary neuropathy with liability to pressure palsies or demyelinating forms of Charcot-Marie-Tooth disease. Together, these data demonstrate the role of Akt in regulatory mechanisms underlying axonal wrapping and myelination in the PNS.
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546
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Ino D, Iino M. In Vivo Gene Transfer to Schwann Cells in the Rodent Sciatic Nerve by Electroporation. J Vis Exp 2016. [PMID: 27683960 PMCID: PMC5091998 DOI: 10.3791/54567] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The formation of the myelin sheath by Schwann cells (SCs) is essential for rapid conduction of nerve impulses along axons in the peripheral nervous system. SC-selective genetic manipulation in living animals is a powerful technique for studying the molecular and cellular mechanisms of SC myelination and demyelination in vivo. While knockout/knockin and transgenic mice are powerful tools for studying SC biology, these methods are costly and time consuming. Viral vector-mediated transgene introduction into the sciatic nerve is a simpler and less laborious method. However, viral methods have limitations, such as toxicity, transgene size constraints, and infectivity restricted to certain developmental stages. Here, we describe a new method that allows selective transfection of myelinating SCs in the rodent sciatic nerve using electroporation. By applying electric pulses to the sciatic nerve at the site of plasmid DNA injection, genes of interest can be easily silenced or overexpressed in SCs in both neonatal and more mature animals. Furthermore, this in vivo electroporation method allows for highly efficient simultaneous expression of multiple transgenes. Our novel technique should enable researchers to efficiently manipulate SC gene expression, and facilitate studies on SC development and function.
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Affiliation(s)
- Daisuke Ino
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo; Laboratory for Cell Polarity Regulation, Quantitative Biology Center, RIKEN;
| | - Masamitsu Iino
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo
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547
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Dietz KC, Polanco JJ, Pol SU, Sim FJ. Targeting human oligodendrocyte progenitors for myelin repair. Exp Neurol 2016; 283:489-500. [PMID: 27001544 PMCID: PMC5666574 DOI: 10.1016/j.expneurol.2016.03.017] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Revised: 03/15/2016] [Accepted: 03/16/2016] [Indexed: 12/31/2022]
Abstract
Oligodendrocyte development has been studied for several decades, and has served as a model system for both neurodevelopmental and stem/progenitor cell biology. Until recently, the vast majority of studies have been conducted in lower species, especially those focused on rodent development and remyelination. In humans, the process of myelination requires the generation of vastly more myelinating glia, occurring over a period of years rather than weeks. Furthermore, as evidenced by the presence of chronic demyelination in a variety of human neurologic diseases, it appears likely that the mechanisms that regulate development and become dysfunctional in disease may be, in key ways, divergent across species. Improvements in isolation techniques, applied to primary human neural and oligodendrocyte progenitors from both fetal and adult brain, as well as advancements in the derivation of defined progenitors from human pluripotent stem cells, have begun to reveal the extent of both species-conserved signaling pathways and potential key differences at cellular and molecular levels. In this article, we will review the commonalities and differences in myelin development between rodents and man, describing the approaches used to study human oligodendrocyte differentiation and myelination, as well as heterogeneity within targetable progenitor pools, and discuss the advances made in determining which conserved pathways may be both modeled in rodents and translate into viable therapeutic strategies to promote myelin repair.
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Affiliation(s)
- Karen C Dietz
- Program in Neuroscience, Department of Pharmacology and Toxicology, School of Medicine and Biomedical Sciences, State University of New York at Buffalo, 3435 Main Street, 119 Farber Hall, Buffalo, NY 14214, United States.
| | - Jessie J Polanco
- Program in Neuroscience, Department of Pharmacology and Toxicology, School of Medicine and Biomedical Sciences, State University of New York at Buffalo, 3435 Main Street, 119 Farber Hall, Buffalo, NY 14214, United States.
| | - Suyog U Pol
- Program in Neuroscience, Department of Pharmacology and Toxicology, School of Medicine and Biomedical Sciences, State University of New York at Buffalo, 3435 Main Street, 119 Farber Hall, Buffalo, NY 14214, United States.
| | - Fraser J Sim
- Program in Neuroscience, Department of Pharmacology and Toxicology, School of Medicine and Biomedical Sciences, State University of New York at Buffalo, 3435 Main Street, 119 Farber Hall, Buffalo, NY 14214, United States.
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548
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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.
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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
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549
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Microglia-induced activation of non-canonical Wnt signaling aggravates neurodegeneration in demyelinating disorders. Mol Cell Biol 2016; 36:2728-2741. [PMID: 27550808 DOI: 10.1128/mcb.00139-16] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Oligodendrocytes are myelinating cells of the central nervous system. Multiple sclerosis (MS) is a demyelinating disease characterized by both myelin loss and neuronal degeneration. However, the molecular mechanisms underlying neuronal degeneration in demyelinating disorders are not fully understood. In the experimental autoimmune encephalomyelitis (EAE) demyelinating mouse model of MS, inflammatory microglia produce cytokines including interleukin-1β (IL-1β). Since microglia and non-canonical Wnt signaling components in neurons, such as the co-receptor Ror2, were observed in the spinal cord of EAE mice, we postulated that the interplay between activated microglia and spinal neurons under EAE conditions is mediated through non-canonical Wnt signaling. EAE treatment up-regulated in vivo expression of non-canonical Wnt signaling components in spinal neurons through microglial activation. In accordance with the neuronal degeneration detected in the EAE spinal cord in vivo, co-culture of spinal neurons with microglia or the application of recombinant IL-1β up-regulated non-canonical Wnt signaling, and induced neuronal cell death, which was suppressed by the inhibition of the Wnt-Ror2 pathway. Ectopic non-canonical Wnt signaling aggravated the demyelinating pathology in another MS mouse model due to Wnt5a-induced neurodegeneration. The linkage between activated microglia and neuronal Wnt-Ror2 signaling may provide a possible candidate target for therapeutic approaches to demyelinating disorders.
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550
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Patzig J, Erwig MS, Tenzer S, Kusch K, Dibaj P, Möbius W, Goebbels S, Schaeren-Wiemers N, Nave KA, Werner HB. Septin/anillin filaments scaffold central nervous system myelin to accelerate nerve conduction. eLife 2016; 5. [PMID: 27504968 PMCID: PMC4978525 DOI: 10.7554/elife.17119] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 07/13/2016] [Indexed: 12/15/2022] Open
Abstract
Myelination of axons facilitates rapid impulse propagation in the nervous system. The axon/myelin-unit becomes impaired in myelin-related disorders and upon normal aging. However, the molecular cause of many pathological features, including the frequently observed myelin outfoldings, remained unknown. Using label-free quantitative proteomics, we find that the presence of myelin outfoldings correlates with a loss of cytoskeletal septins in myelin. Regulated by phosphatidylinositol-(4,5)-bisphosphate (PI(4,5)P2)-levels, myelin septins (SEPT2/SEPT4/SEPT7/SEPT8) and the PI(4,5)P2-adaptor anillin form previously unrecognized filaments that extend longitudinally along myelinated axons. By confocal microscopy and immunogold-electron microscopy, these filaments are localized to the non-compacted adaxonal myelin compartment. Genetic disruption of these filaments in Sept8-mutant mice causes myelin outfoldings as a very specific neuropathology. Septin filaments thus serve an important function in scaffolding the axon/myelin-unit, evidently a late stage of myelin maturation. We propose that pathological or aging-associated diminishment of the septin/anillin-scaffold causes myelin outfoldings that impair the normal nerve conduction velocity. DOI:http://dx.doi.org/10.7554/eLife.17119.001 Normal communication within the brain or between the brain and other parts of the body requires information to flow quickly around the nervous system. This information travels along nerve cells in the form of electrical signals. To speed up the signals, a part of the nerve cell called the axon is frequently wrapped in an electrically insulating sheath made up of a membrane structure called myelin. The myelin sheath becomes impaired as a result of disease or ageing. In order to understand what might produce these changes, Patzig et al. have used biochemical and microscopy techniques to study mice that had similar defects in their myelin sheaths. The study reveals that forming a normal myelin sheath around an axon requires a newly identified ‘scaffold’ made of a group of proteins called the septins. Combining with another protein called anillin, septins assemble into filaments in the myelin sheath. These filaments then knit together into a scaffold that grows lengthways along the myelin-wrapped axon. Without this scaffold, the myelin sheath grew defects known as outfoldings. Axons transmitted electrical signals much more slowly than normal when the septin scaffold was missing from the myelin sheath. Future studies are needed to understand the factors that control how the septin scaffold forms. This could help to reveal ways of reversing the changes that alter the myelin sheath during ageing and disease. DOI:http://dx.doi.org/10.7554/eLife.17119.002
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Affiliation(s)
- Julia Patzig
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Goettingen, Germany
| | - Michelle S Erwig
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Goettingen, Germany
| | - Stefan Tenzer
- Institute of Immunology, University Medical Center, Johannes Gutenberg University, Mainz, Germany
| | - Kathrin Kusch
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Goettingen, Germany
| | - Payam Dibaj
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Goettingen, Germany
| | - Wiebke Möbius
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Goettingen, Germany.,Center for Nanoscale Microscopy and Molecular Physiology of the Brain, Göttingen, Germany
| | - Sandra Goebbels
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Goettingen, Germany
| | | | - Klaus-Armin Nave
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Goettingen, Germany.,Center for Nanoscale Microscopy and Molecular Physiology of the Brain, Göttingen, Germany
| | - Hauke B Werner
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Goettingen, Germany
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