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Tran NT, Muccini AM, Hale N, Tolcos M, Snow RJ, Walker DW, Ellery SJ. Creatine in the fetal brain: A regional investigation of acute global hypoxia and creatine supplementation in a translational fetal sheep model. Front Cell Neurosci 2023; 17:1154772. [PMID: 37066075 PMCID: PMC10097948 DOI: 10.3389/fncel.2023.1154772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 03/15/2023] [Indexed: 04/18/2023] Open
Abstract
Background Creatine supplementation during pregnancy is a promising prophylactic treatment for perinatal hypoxic brain injury. Previously, in near-term sheep we have shown that fetal creatine supplementation reduces cerebral metabolic and oxidative stress induced by acute global hypoxia. This study investigated the effects of acute hypoxia with or without fetal creatine supplementation on neuropathology in multiple brain regions. Methods Near-term fetal sheep were administered continuous intravenous infusion of either creatine (6 mg kg-1 h-1) or isovolumetric saline from 122 to 134 days gestational age (dGA; term is approx. 145 dGA). At 131 dGA, global hypoxia was induced by a 10 min umbilical cord occlusion (UCO). Fetuses were then recovered for 72 h at which time (134 dGA) cerebral tissue was collected for either RT-qPCR or immunohistochemistry analyses. Results UCO resulted in mild injury to the cortical gray matter, thalamus and hippocampus, with increased cell death and astrogliosis and downregulation of genes involved in regulating injury responses, vasculature development and mitochondrial integrity. Creatine supplementation reduced astrogliosis within the corpus callosum but did not ameliorate any other gene expression or histopathological changes induced by hypoxia. Of importance, effects of creatine supplementation on gene expression irrespective of hypoxia, including increased expression of anti-apoptotic (BCL-2) and pro-inflammatory (e.g., MPO, TNFa, IL-6, IL-1β) genes, particularly in the gray matter, hippocampus, and striatum were identified. Creatine treatment also effected oligodendrocyte maturation and myelination in white matter regions. Conclusion While supplementation did not rescue mild neuropathology caused by UCO, creatine did result in gene expression changes that may influence in utero cerebral development.
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Affiliation(s)
- Nhi T. Tran
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia
- Department of Obstetrics and Gynaecology, Monash University, Melbourne, VIC, Australia
- School of Health and Biomedical Sciences, RMIT University, Melbourne, VIC, Australia
- *Correspondence: Nhi T. Tran,
| | - Anna M. Muccini
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia
| | - Nadia Hale
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia
| | - Mary Tolcos
- School of Health and Biomedical Sciences, RMIT University, Melbourne, VIC, Australia
| | - Rod J. Snow
- Institute for Physical Activity and Nutrition, Deakin University, Melbourne, VIC, Australia
| | - David W. Walker
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia
- Department of Obstetrics and Gynaecology, Monash University, Melbourne, VIC, Australia
- School of Health and Biomedical Sciences, RMIT University, Melbourne, VIC, Australia
| | - Stacey J. Ellery
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia
- Department of Obstetrics and Gynaecology, Monash University, Melbourne, VIC, Australia
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Ishino Y, Shimizu S, Tohyama M, Miyata S. Coactivator‐associated arginine methyltransferase 1 controls oligodendrocyte differentiation in the corpus callosum during early brain development. Dev Neurobiol 2022; 82:245-260. [DOI: 10.1002/dneu.22871] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 01/07/2022] [Accepted: 01/27/2022] [Indexed: 11/10/2022]
Affiliation(s)
- Yugo Ishino
- Division of Molecular Brain Science Research Institute of Traditional Asian Medicine Kindai University Osaka‐Sayama Osaka 589–8511 Japan
| | - Shoko Shimizu
- Division of Molecular Brain Science Research Institute of Traditional Asian Medicine Kindai University Osaka‐Sayama Osaka 589–8511 Japan
| | - Masaya Tohyama
- Division of Molecular Brain Science Research Institute of Traditional Asian Medicine Kindai University Osaka‐Sayama Osaka 589–8511 Japan
| | - Shingo Miyata
- Division of Molecular Brain Science Research Institute of Traditional Asian Medicine Kindai University Osaka‐Sayama Osaka 589–8511 Japan
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Duncan GJ, Simkins TJ, Emery B. Neuron-Oligodendrocyte Interactions in the Structure and Integrity of Axons. Front Cell Dev Biol 2021; 9:653101. [PMID: 33763430 PMCID: PMC7982542 DOI: 10.3389/fcell.2021.653101] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 02/15/2021] [Indexed: 12/12/2022] Open
Abstract
The myelination of axons by oligodendrocytes is a highly complex cell-to-cell interaction. Oligodendrocytes and axons have a reciprocal signaling relationship in which oligodendrocytes receive cues from axons that direct their myelination, and oligodendrocytes subsequently shape axonal structure and conduction. Oligodendrocytes are necessary for the maturation of excitatory domains on the axon including nodes of Ranvier, help buffer potassium, and support neuronal energy metabolism. Disruption of the oligodendrocyte-axon unit in traumatic injuries, Alzheimer's disease and demyelinating diseases such as multiple sclerosis results in axonal dysfunction and can culminate in neurodegeneration. In this review, we discuss the mechanisms by which demyelination and loss of oligodendrocytes compromise axons. We highlight the intra-axonal cascades initiated by demyelination that can result in irreversible axonal damage. Both the restoration of oligodendrocyte myelination or neuroprotective therapies targeting these intra-axonal cascades are likely to have therapeutic potential in disorders in which oligodendrocyte support of axons is disrupted.
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Affiliation(s)
- Greg J. Duncan
- Jungers Center for Neurosciences Research, Department of Neurology, Oregon Health & Science University, Portland, OR, United States
| | - Tyrell J. Simkins
- Jungers Center for Neurosciences Research, Department of Neurology, Oregon Health & Science University, Portland, OR, United States
- Vollum Institute, Oregon Health & Science University, Portland, OR, United States
- Department of Neurology, VA Portland Health Care System, Portland, OR, United States
| | - Ben Emery
- Jungers Center for Neurosciences Research, Department of Neurology, Oregon Health & Science University, Portland, OR, United States
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Lubetzki C, Sol-Foulon N, Desmazières A. Nodes of Ranvier during development and repair in the CNS. Nat Rev Neurol 2020; 16:426-439. [DOI: 10.1038/s41582-020-0375-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/04/2020] [Indexed: 01/01/2023]
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Enright HA, Lam D, Sebastian A, Sales AP, Cadena J, Hum NR, Osburn JJ, Peters SKG, Petkus B, Soscia DA, Kulp KS, Loots GG, Wheeler EK, Fischer NO. Functional and transcriptional characterization of complex neuronal co-cultures. Sci Rep 2020; 10:11007. [PMID: 32620908 PMCID: PMC7335084 DOI: 10.1038/s41598-020-67691-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Accepted: 06/08/2020] [Indexed: 12/03/2022] Open
Abstract
Brain-on-a-chip systems are designed to simulate brain activity using traditional in vitro cell culture on an engineered platform. It is a noninvasive tool to screen new drugs, evaluate toxicants, and elucidate disease mechanisms. However, successful recapitulation of brain function on these systems is dependent on the complexity of the cell culture. In this study, we increased cellular complexity of traditional (simple) neuronal cultures by co-culturing with astrocytes and oligodendrocyte precursor cells (complex culture). We evaluated and compared neuronal activity (e.g., network formation and maturation), cellular composition in long-term culture, and the transcriptome of the two cultures. Compared to simple cultures, neurons from complex co-cultures exhibited earlier synapse and network development and maturation, which was supported by localized synaptophysin expression, up-regulation of genes involved in mature neuronal processes, and synchronized neural network activity. Also, mature oligodendrocytes and reactive astrocytes were only detected in complex cultures upon transcriptomic analysis of age-matched cultures. Functionally, the GABA antagonist bicuculline had a greater influence on bursting activity in complex versus simple cultures. Collectively, the cellular complexity of brain-on-a-chip systems intrinsically develops cell type-specific phenotypes relevant to the brain while accelerating the maturation of neuronal networks, important features underdeveloped in traditional cultures.
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Affiliation(s)
- Heather A Enright
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA.
| | - Doris Lam
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Aimy Sebastian
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Ana Paula Sales
- Engineering Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Jose Cadena
- Engineering Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Nicholas R Hum
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA.,University of California, Merced, School of Natural Sciences, Merced, CA, USA
| | - Joanne J Osburn
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Sandra K G Peters
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Bryan Petkus
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - David A Soscia
- Engineering Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Kristen S Kulp
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Gabriela G Loots
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA.,University of California, Merced, School of Natural Sciences, Merced, CA, USA
| | - Elizabeth K Wheeler
- Engineering Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Nicholas O Fischer
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA.
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Abstract
Remyelination is limited in the majority of multiple sclerosis (MS) lesions despite the presence of oligodendrocyte precursor cells (OPCs) in most lesions. This observation has led to the view that a failure of OPCs to fully differentiate underlies remyelination failure. OPC differentiation requires intricate transcriptional regulation, which may be disrupted in chronic MS lesions. The expression of few transcription factors has been differentially compared between remyelinating lesions and lesions refractory to remyelination. In particular, the oligodendrocyte transcription factor myelin regulatory factor (MYRF) is essential for myelination during development, but its role during remyelination and expression in MS lesions is unknown. To understand the role of MYRF during remyelination, we genetically fate mapped OPCs following lysolecithin-induced demyelination of the corpus callosum in mice and determined that MYRF is expressed in new oligodendrocytes. OPC-specific Myrf deletion did not alter recruitment or proliferation of these cells after demyelination, but decreased the density of new glutathione S-transferase π positive oligodendrocytes. Subsequent remyelination in both the spinal cord and corpus callosum is highly impaired following Myrf deletion from OPCs. Individual OPC-derived oligodendrocytes, produced in response to demyelination, showed little capacity to express myelin proteins following Myrf deletion. Collectively, these data demonstrate a crucial role of MYRF in the transition of oligodendrocytes from a premyelinating to a myelinating phenotype during remyelination. In the human brain, we find that MYRF is expressed in NogoA and CNP-positive oligodendrocytes. In MS, there was both a lower density and proportion of oligodendrocyte lineage cells and NogoA+ oligodendrocytes expressing MYRF in chronically demyelinated lesions compared to remyelinated shadow plaques. The relative scarcity of oligodendrocyte lineage cells expressing MYRF in demyelinated MS lesions demonstrates, for the first time, that chronic lesions lack oligodendrocytes that express this necessary transcription factor for remyelination and supports the notion that a failure to fully differentiate underlies remyelination failure.
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Freeman SA, Desmazières A, Fricker D, Lubetzki C, Sol-Foulon N. Mechanisms of sodium channel clustering and its influence on axonal impulse conduction. Cell Mol Life Sci 2016; 73:723-35. [PMID: 26514731 PMCID: PMC4735253 DOI: 10.1007/s00018-015-2081-1] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 10/21/2015] [Accepted: 10/22/2015] [Indexed: 12/16/2022]
Abstract
The efficient propagation of action potentials along nervous fibers is necessary for animals to interact with the environment with timeliness and precision. Myelination of axons is an essential step to ensure fast action potential propagation by saltatory conduction, a process that requires highly concentrated voltage-gated sodium channels at the nodes of Ranvier. Recent studies suggest that the clustering of sodium channels can influence axonal impulse conduction in both myelinated and unmyelinated fibers, which could have major implications in disease, particularly demyelinating pathology. This comprehensive review summarizes the mechanisms governing the clustering of sodium channels at the peripheral and central nervous system nodes and the specific roles of their clustering in influencing action potential conduction. We further highlight the classical biophysical parameters implicated in conduction timing, followed by a detailed discussion on how sodium channel clustering along unmyelinated axons can impact axonal impulse conduction in both physiological and pathological contexts.
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Affiliation(s)
- Sean A Freeman
- ICM-GHU Pitié-Salpêtrière, Sorbonne Universités UPMC Univ Paris 06, UMR_S 1127, 75013, Paris, France.
- Inserm U1127, 75013, Paris, France.
- CNRS UMR7225, 75013, Paris, France.
| | - Anne Desmazières
- ICM-GHU Pitié-Salpêtrière, Sorbonne Universités UPMC Univ Paris 06, UMR_S 1127, 75013, Paris, France.
- Inserm U1127, 75013, Paris, France.
- CNRS UMR7225, 75013, Paris, France.
| | - Desdemona Fricker
- ICM-GHU Pitié-Salpêtrière, Sorbonne Universités UPMC Univ Paris 06, UMR_S 1127, 75013, Paris, France.
- Inserm U1127, 75013, Paris, France.
- CNRS UMR7225, 75013, Paris, France.
| | - Catherine Lubetzki
- ICM-GHU Pitié-Salpêtrière, Sorbonne Universités UPMC Univ Paris 06, UMR_S 1127, 75013, Paris, France.
- Inserm U1127, 75013, Paris, France.
- CNRS UMR7225, 75013, Paris, France.
- Assistance Publique-Hôpitaux de Paris, Hôpital Pitié-Salpêtrière, Paris, France.
| | - Nathalie Sol-Foulon
- ICM-GHU Pitié-Salpêtrière, Sorbonne Universités UPMC Univ Paris 06, UMR_S 1127, 75013, Paris, France.
- Inserm U1127, 75013, Paris, France.
- CNRS UMR7225, 75013, Paris, France.
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Acceleration of conduction velocity linked to clustering of nodal components precedes myelination. Proc Natl Acad Sci U S A 2015; 112:E321-8. [PMID: 25561543 DOI: 10.1073/pnas.1419099112] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
High-density accumulation of voltage-gated sodium (Nav) channels at nodes of Ranvier ensures rapid saltatory conduction along myelinated axons. To gain insight into mechanisms of node assembly in the CNS, we focused on early steps of nodal protein clustering. We show in hippocampal cultures that prenodes (i.e., clusters of Nav channels colocalizing with the scaffold protein ankyrinG and nodal cell adhesion molecules) are detected before myelin deposition along axons. These clusters can be induced on purified neurons by addition of oligodendroglial-secreted factor(s), whereas ankyrinG silencing prevents their formation. The Nav isoforms Nav1.1, Nav1.2, and Nav1.6 are detected at prenodes, with Nav1.6 progressively replacing Nav1.2 over time in hippocampal neurons cultured with oligodendrocytes and astrocytes. However, the oligodendrocyte-secreted factor(s) can induce the clustering of Nav1.1 and Nav1.2 but not of Nav1.6 on purified neurons. We observed that prenodes are restricted to GABAergic neurons, whereas clustering of nodal proteins only occurs concomitantly with myelin ensheathment on pyramidal neurons, implying separate mechanisms of assembly among different neuronal subpopulations. To address the functional significance of these early clusters, we used single-axon electrophysiological recordings in vitro and showed that prenode formation is sufficient to accelerate the speed of axonal conduction before myelination. Finally, we provide evidence that prenodal clusters are also detected in vivo before myelination, further strengthening their physiological relevance.
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Abstract
This review, focused on demyelination in multiple sclerosis, is divided in two parts. The first part addresses the many and not exclusive mechanisms leading to demyelination in the central nervous system. Although the hypothesis that a primary oligodendrocyte or myelin injury induces a secondary immune response in the central nervous system is still a matter of debate, most recent advances underline the influence of a primary immune response against myelin antigen(s), with a diversity of potential targets. Whereas multiple sclerosis was long considered as a T cell-mediated disease, the role of B lymphocytes is now increasingly recognized, and the influence of antibodies on tissue damage actively investigated. The second part of the review describes the axonal consequences of demyelination. Segmental demyelination results in conduction block or slowing of conduction through adaptative responses, notably related to modifications in the distribution of voltage gated sodium channels along the denuded axon. If demyelination persists, these changes, as well as the loss of trophic and metabolic support, will lead to irreversible axonal damage and loss. In this respect, favouring early myelin repair, during a window of time when axonal damage is still reversible, might pave the way for neuroprotection.
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Affiliation(s)
- Catherine Lubetzki
- Correspondence to: Professeur Catherine Lubetzki, CRICM, UPMC/Inserm UMR_S975, GH Pitié-Salpêtrière, Bâtiment ICM, 47 Bld de l'Hôpital, 75651 Paris cedex 13, France. Tel: + 33-01-57-27-44-65
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Zoupi L, Markoullis K, Kleopa KA, Karagogeos D. Alterations of juxtaparanodal domains in two rodent models of CNS demyelination. Glia 2013; 61:1236-49. [DOI: 10.1002/glia.22511] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Accepted: 03/20/2013] [Indexed: 01/15/2023]
Affiliation(s)
| | - Kyriaki Markoullis
- Neuroscience Laboratory and Neurology Clinics; The Cyprus Institute of Neurology and Genetics (CING); P.O. Box 23462, 1683 Nicosia; Cyprus
| | - Kleopas A. Kleopa
- Neuroscience Laboratory and Neurology Clinics; The Cyprus Institute of Neurology and Genetics (CING); P.O. Box 23462, 1683 Nicosia; Cyprus
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Gonzalez-Perez O, Alvarez-Buylla A. Oligodendrogenesis in the subventricular zone and the role of epidermal growth factor. BRAIN RESEARCH REVIEWS 2011; 67:147-56. [PMID: 21236296 PMCID: PMC3109119 DOI: 10.1016/j.brainresrev.2011.01.001] [Citation(s) in RCA: 114] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2010] [Revised: 01/04/2011] [Accepted: 01/05/2011] [Indexed: 01/18/2023]
Abstract
Demyelinating diseases are characterized by an extensive loss of oligodendrocytes and myelin sheaths from axolemma. These neurological disorders are a common cause of disability in young adults, but so far, there is no effective treatment against them. It has been suggested that neural stem cells (NSCs) may play an important role in brain repair therapies. NSCs in the adult subventricular zone (SVZ), also known as Type-B cells, are multipotential cells that can self-renew and give rise to neurons and glia. Recent findings have shown that cells derived from SVZ Type-B cells actively respond to epidermal-growth-factor (EGF) stimulation becoming highly migratory and proliferative. Interestingly, a subpopulation of these EGF-activated cells expresses markers of oligodendrocyte precursor cells (OPCs). When EGF administration is removed, SVZ-derived OPCs differentiate into myelinating and pre-myelinating oligodendrocytes in the white matter tracts of corpus callosum, fimbria fornix and striatum. In the presence of a demyelinating lesion, OPCs derived from EGF-stimulated SVZ progenitors contribute to myelin repair. Given their high migratory potential and their ability to differentiate into myelin-forming cells, SVZ NSCs represent an important endogenous source of OPCs for preserving the oligodendrocyte population in the white matter and for the repair of demyelinating injuries.
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Affiliation(s)
- Oscar Gonzalez-Perez
- Laboratory of Neuroscience, School of Psychology, University of Colima, Colima, Colima 28040, Mexico.
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Oligodendrocytes as regulators of neuronal networks during early postnatal development. PLoS One 2011; 6:e19849. [PMID: 21589880 PMCID: PMC3093406 DOI: 10.1371/journal.pone.0019849] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2010] [Accepted: 04/18/2011] [Indexed: 11/30/2022] Open
Abstract
Oligodendrocytes are the glial cells responsible for myelin formation. Myelination occurs during the first postnatal weeks and, in rodents, is completed during the third week after birth. Myelin ensures the fast conduction of the nerve impulse; in the adult, myelin proteins have an inhibitory role on axon growth and regeneration after injury. During brain development, oligodendrocytes precursors originating in multiple locations along the antero-posterior axis actively proliferate and migrate to colonize the whole brain. Whether the initial interactions between oligodendrocytes and neurons might play a functional role before the onset of myelination is still not completely elucidated. In this article, we addressed this question by transgenically targeted ablation of proliferating oligodendrocytes during cerebellum development. Interestingly, we show that depletion of oligodendrocytes at postnatal day 1 (P1) profoundly affects the establishment of cerebellar circuitries. We observed an impressive deregulation in the expression of molecules involved in axon growth, guidance and synaptic plasticity. These effects were accompanied by an outstanding increase of neurofilament staining observed 4 hours after the beginning of the ablation protocol, likely dependent from sprouting of cerebellar fibers. Oligodendrocyte ablation modifies localization and function of ionotropic glutamate receptors in Purkinje neurons. These results show a novel oligodendrocyte function expressed during early postnatal brain development, where these cells participate in the formation of cerebellar circuitries, and influence its development.
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Cifuentes-Diaz C, Dubourg O, Irinopoulou T, Vigny M, Lachkar S, Decker L, Charnay P, Denisenko N, Maisonobe T, Léger JM, Viala K, Hauw JJ, Girault JA. Nodes of ranvier and paranodes in chronic acquired neuropathies. PLoS One 2011; 6:e14533. [PMID: 21267074 PMCID: PMC3022580 DOI: 10.1371/journal.pone.0014533] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2010] [Accepted: 12/10/2010] [Indexed: 11/18/2022] Open
Abstract
Chronic acquired neuropathies of unknown origin are classified as chronic inflammatory demyelinating polyneuropathies (CIDP) and chronic idiopathic axonal polyneuropathies (CIAP). The diagnosis can be very difficult, although it has important therapeutic implications since CIDP can be improved by immunomodulating treatment. The aim of this study was to examine the possible abnormalities of nodal and paranodal regions in these two types of neuropathies. Longitudinal sections of superficial peroneal nerves were obtained from biopsy material from 12 patients with CIDP and 10 patients with CIAP and studied by immunofluorescence and in some cases electron microscopy. Electron microscopy revealed multiple alterations in the nodal and paranodal regions which predominated in Schwann cells in CIDP and in axons in CIAP. In CIDP paranodin/Caspr immunofluorescence was more widespread than in control nerves, extending along the axon in internodes where it appeared intense. Nodal channels Nav and KCNQ2 were less altered but were also detected in the internodes. In CIAP paranodes, paranodin labeling was irregular and/or decreased. To test the consequences of acquired primary Schwann cells alteration on axonal proteins, we used a mouse model based on induced deletion of the transcription factor Krox-20 gene. In the demyelinated sciatic nerves of these mice we observed alterations similar to those found in CIDP by immunofluorescence, and immunoblotting demonstrated increased levels of paranodin. Finally we examined whether the alterations in paranodin immunoreactivity could have a diagnosis value. In a sample of 16 biopsies, the study of paranodin immunofluorescence by blind evaluators led to correct diagnosis in 70 ± 4% of the cases. This study characterizes for the first time the abnormalities of nodes of Ranvier in CIAP and CIDP, and the altered expression and distribution of nodal and paranodal proteins. Marked differences were observed between CIDP and CIAP and the alterations in paranodin immunofluorescence may be an interesting tool for their differential diagnosis.
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Affiliation(s)
- Carmen Cifuentes-Diaz
- Institut National de la Santé et de la Recherche Médicale (Inserm), Unité Mixte de Recherche en Santé (UMR-S) 839, Paris, France
- Université Pierre et Marie Curie (UPMC), Paris, France
- Institut du Fer à Moulin, Paris, France
| | - Odile Dubourg
- Laboratoire de Neuropathologie Raymond-Escourolle, Pitié-Salpêtrière Hospital, Assistance Publique des Hôpitaux de Paris (AP-HP), Paris, France
- Consultation de Pathologie Neuromusculaire, Centre de Référence de Paris Est, Pitié-Salpêtrière Hospital, AP-HP, Paris, France
| | - Theano Irinopoulou
- Institut National de la Santé et de la Recherche Médicale (Inserm), Unité Mixte de Recherche en Santé (UMR-S) 839, Paris, France
- Université Pierre et Marie Curie (UPMC), Paris, France
- Institut du Fer à Moulin, Paris, France
| | - Marc Vigny
- Institut National de la Santé et de la Recherche Médicale (Inserm), Unité Mixte de Recherche en Santé (UMR-S) 839, Paris, France
- Université Pierre et Marie Curie (UPMC), Paris, France
- Institut du Fer à Moulin, Paris, France
| | - Sylvie Lachkar
- Institut National de la Santé et de la Recherche Médicale (Inserm), Unité Mixte de Recherche en Santé (UMR-S) 839, Paris, France
- Université Pierre et Marie Curie (UPMC), Paris, France
- Institut du Fer à Moulin, Paris, France
| | - Laurence Decker
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Inserm U1024, Centre National de la Recherche Scientifique (CNRS) UMR 8197, Ecole Normale Supérieure, Paris, France
| | - Patrick Charnay
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Inserm U1024, Centre National de la Recherche Scientifique (CNRS) UMR 8197, Ecole Normale Supérieure, Paris, France
| | - Natalia Denisenko
- Institut National de la Santé et de la Recherche Médicale (Inserm), Unité Mixte de Recherche en Santé (UMR-S) 839, Paris, France
- Université Pierre et Marie Curie (UPMC), Paris, France
- Institut du Fer à Moulin, Paris, France
| | - Thierry Maisonobe
- Laboratoire de Neuropathologie Raymond-Escourolle, Pitié-Salpêtrière Hospital, Assistance Publique des Hôpitaux de Paris (AP-HP), Paris, France
- Fédération de Neurophysiologie Clinique and Fédération de Neurologie, Pitié-Salpêtrière Hospital, AP-HP, Paris, France
| | - Jean-Marc Léger
- Consultation de Pathologie Neuromusculaire, Centre de Référence de Paris Est, Pitié-Salpêtrière Hospital, AP-HP, Paris, France
| | - Karine Viala
- Fédération de Neurophysiologie Clinique and Fédération de Neurologie, Pitié-Salpêtrière Hospital, AP-HP, Paris, France
| | - Jean-Jacques Hauw
- Université Pierre et Marie Curie (UPMC), Paris, France
- Laboratoire de Neuropathologie Raymond-Escourolle, Pitié-Salpêtrière Hospital, Assistance Publique des Hôpitaux de Paris (AP-HP), Paris, France
| | - Jean-Antoine Girault
- Institut National de la Santé et de la Recherche Médicale (Inserm), Unité Mixte de Recherche en Santé (UMR-S) 839, Paris, France
- Université Pierre et Marie Curie (UPMC), Paris, France
- Institut du Fer à Moulin, Paris, France
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Activated microglia mediate axoglial disruption that contributes to axonal injury in multiple sclerosis. J Neuropathol Exp Neurol 2010; 69:1017-1033. [PMID: 20838243 DOI: 10.1097/nen.0b013e3181f3a5b1] [Citation(s) in RCA: 167] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
The complex manifestations of chronic multiple sclerosis (MS)are due in part to widespread axonal abnormalities that affect lesional and nonlesional areas in the central nervous system. We describe an association between microglial activation and axon/oligodendrocyte pathology at nodal and paranodal domains in normal-appearing white matter (NAWM) of MS cases and in experimental autoimmune encephalomyelitis (EAE). The extent of paranodal axoglial (neurofascin-155(+)/Caspr1(+)) disruption correlated with local microglial inflammation and axonal injury (expression of nonphosphorylated neurofilaments) in MS NAWM. These changes were independent of demyelinating lesions and did not correlate with the density of infiltrating lymphocytes. Similar axoglial alterations were seen in the subcortical white matter of Parkinson disease cases and in preclinical EAE, at a time point when there is microglial activation before the infiltration of immune cells. Disruption of the axoglial unit in adjuvant-immunized animals was reversible and coincided with the resolution of microglial inflammation; paranodal damage and microglial inflammation persisted in chronic EAE. Axoglial integrity could be preserved by the administration of minocycline, which inhibited microglial activation, in actively immunized animals. These data indicate that, in MS NAWM, permanent disruption to axoglial domains in an environment of microglial inflammation is an early indicator of axonal injury that likely affects nerve conduction and may contribute to physiologic dysfunction.
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15
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Parenti R, Cicirata F, Zappalà A, Catania A, La Delia F, Cicirata V, Tress O, Willecke K. Dynamic expression of Cx47 in mouse brain development and in the cuprizone model of myelin plasticity. Glia 2010; 58:1594-609. [DOI: 10.1002/glia.21032] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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16
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Crawford DK, Mangiardi M, Xia X, López-Valdés HE, Tiwari-Woodruff SK. Functional recovery of callosal axons following demyelination: a critical window. Neuroscience 2009; 164:1407-21. [PMID: 19800949 DOI: 10.1016/j.neuroscience.2009.09.069] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2009] [Revised: 09/24/2009] [Accepted: 09/28/2009] [Indexed: 01/14/2023]
Abstract
Axonal dysfunction as a result of persistent demyelination has been increasingly appreciated as a cause of functional deficit in demyelinating diseases such as multiple sclerosis. Therefore, it is crucial to understand the ultimate causes of ongoing axonal dysfunction and find effective measures to prevent axon loss. Our findings related to functional deficit and functional recovery of axons from a demyelinating insult are important preliminary steps towards understanding this issue. Cuprizone diet for 3-6 wks triggered extensive corpus callosum (CC) demyelination, reduced axon conduction, and resulted in loss of axon structural integrity including nodes of Ranvier. Replacing cuprizone diet with normal diet led to regeneration of myelin, but did not fully reverse the conduction and structural deficits. A shorter 1.5 wk cuprizone diet also caused demyelination of the CC, with minimal loss of axon structure and nodal organization. Switching to normal diet led to remyelination and restored callosal axon conduction to normal levels. Our findings suggest the existence of a critical window of time for remyelination, beyond which demyelinated axons become damaged beyond the point of repair and permanent functional loss follows. Moreover, initiating remyelination early within the critical period, before prolonged demyelination-induced axon damage ensues, will improve functional axon recovery and inhibit disease progression.
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Affiliation(s)
- D K Crawford
- Multiple Sclerosis Program, Department of Neurology, School of Medicine, University of California Los Angeles, Los Angeles, CA 90095-1769, USA
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17
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Goto J, Tezuka T, Nakazawa T, Sagara H, Yamamoto T. Loss of Fyn tyrosine kinase on the C57BL/6 genetic background causes hydrocephalus with defects in oligodendrocyte development. Mol Cell Neurosci 2008; 38:203-12. [PMID: 18403215 DOI: 10.1016/j.mcn.2008.02.009] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2007] [Revised: 01/16/2008] [Accepted: 02/14/2008] [Indexed: 12/01/2022] Open
Abstract
The supportive functions of oligodendrocytes are required for the survival and development of axons, ensuring the organization of highly specialized neuronal networks in brain. Although the molecules that regulate oligodendrocyte differentiation in vitro have been identified, their roles in vivo are largely uncertain. Here we report that fyn deficiency on the C57BL/6 genetic background resulted in premature death, showing severe hydrocephalus with neonatal onset. One week after birth, fyn-deficient mice showed enlarged lateral ventricles with thinner cerebral cortices and degenerating axons in the corpus callosum. In addition, before the onset of myelination, the number of oligodendrocytes was reduced and their morphogenesis was impaired in the cerebral cortex. These results demonstrate that Fyn is essential for normal brain development and suggest that defects in oligodendrocyte development cause degeneration of cortical axons and subsequent hydrocephalus in fyn-deficient mice.
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Affiliation(s)
- June Goto
- Division of Oncology, Department of Cancer Biology, Institute of Medical Science, University of Tokyo, Minato-ku, Tokyo 108-8639, Japan
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18
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Palminiello S, Kida E, Kaur K, Walus M, Wisniewski KE, Wierzba-Bobrowicz T, Rabe A, Albertini G, Golabek AA. Increased levels of carbonic anhydrase II in the developing Down syndrome brain. Brain Res 2008; 1190:193-205. [DOI: 10.1016/j.brainres.2007.11.023] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2007] [Revised: 11/07/2007] [Accepted: 11/08/2007] [Indexed: 11/26/2022]
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19
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Collin L, Doretto S, Malerba M, Ruat M, Borrelli E. Oligodendrocyte ablation affects the coordinated interaction between granule and Purkinje neurons during cerebellum development. Exp Cell Res 2007; 313:2946-57. [PMID: 17544395 DOI: 10.1016/j.yexcr.2007.05.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2007] [Revised: 05/01/2007] [Accepted: 05/02/2007] [Indexed: 01/06/2023]
Abstract
Oligodendrocytes (OLs) are the glial cells of the central nervous system (CNS) classically known to be devoted to the formation of myelin sheaths around most axons of the vertebrate brain. We have addressed the role of these cells during cerebellar development, by ablating OLs in vivo. Previous analyses had indicated that OL ablation during the first six postnatal days results into a striking cerebellar phenotype, whose major features are a strong reduction of granule neurons and aberrant Purkinje cells development. These two cell types are highly interconnected during cerebellar development through the production of molecules that help their proliferation, differentiation and maintenance. In this article, we present data showing that OL ablation has major effects on the physiology of Purkinje (PC) and granule cells (GC). In particular, OL ablation results into a reduction of sonic hedgehog (Shh), Brain Derived Neurotrophic Factor (BDNF), and Reelin (Rln) expression. These results indicate that absence of OLs profoundly alters the normal cerebellar developmental program.
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Affiliation(s)
- Ludovic Collin
- Institut de Genetique et de Biologie Moleculaire et Cellulaire, 1 rue L Fries 67404, Illkirch, France
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20
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Kida E, Palminiello S, Golabek AA, Walus M, Wierzba-Bobrowicz T, Rabe A, Albertini G, Wisniewski KE. Carbonic anhydrase II in the developing and adult human brain. J Neuropathol Exp Neurol 2006; 65:664-74. [PMID: 16825953 DOI: 10.1097/01.jnen.0000225905.52002.3e] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Carbonic anhydrase II (CA II) is one of 14 isozymes of carbonic anhydrases, zinc metalloenzymes that catalyze the reversible hydration of carbon dioxide to bicarbonate. Mutations in CA II in humans lead to osteopetrosis with renal tubular acidosis and cerebral calcifications, a disorder often associated with mental retardation. Recently, new avenues in CA II research have opened as a result of discoveries that the enzyme increases bicarbonate and proton fluxes and may play an important role in brain tissue. In the human brain, CA II was localized to oligodendrocytes, myelin, and choroid plexus epithelium. Because this conclusion was based on a few fragmentary reports, we analyzed in more detail the expression of the enzyme in human telencephalon. By immunoblotting, we found a gradual increase in CA II levels from 17 weeks' gestation to childhood and adolescence. By immunohistochemistry, CA II was found to be present not only in oligodendrocytes and choroid plexus epithelium (declining with aging in both these locations), but also in a subset of neurons mostly with GABAergic phenotype, in a few astrocytes, and transiently during brain development in the endothelial cells of microvessels. The enzyme also occurred in oligodendrocyte processes in contact with myelinating axons, myelin sheaths, and axolemma, but was either absent or appeared in minute amounts in compact myelin. These findings suggest the possible involvement of CA II in a wide spectrum of biologic processes in the developing and adult human brain and may contribute to better understanding of the pathogenesis of cerebral calcifications and mental retardation caused by CA II deficiency.
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Affiliation(s)
- Elizabeth Kida
- Department of Developmental Neurobiology, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York 10314, USA.
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21
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Adriani W, Leo D, Guarino M, Natoli A, Di Consiglio E, De Angelis G, Traina E, Testai E, Perrone-Capano C, Laviola G. Short-Term Effects of Adolescent Methylphenidate Exposure on Brain Striatal Gene Expression and Sexual/Endocrine Parameters in Male Rats. Ann N Y Acad Sci 2006; 1074:52-73. [PMID: 17105903 DOI: 10.1196/annals.1369.005] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Exposure to methylphenidate (MPH) during adolescence is the elective therapy for attention deficit/hyperactivity disorder (ADHD) children, but raises major concerns for public health, due to possibly persistent neurobehavioral changes. Rats (30- to 44-days old) were administered MPH (2 mg/kg, i.p once daily) or saline (SAL). At the end of the treatment we collected plasma, testicular, liver, and brain (striatum) samples. The testes and liver were used to evaluate conventional reproductive and metabolic endpoints. Testes of MPH-exposed rats weighed more and contained an increased quantity of sperm, whereas testicular levels of testosterone (TST) were markedly decreased. The MPH treatment exerted an inductive effect on enzymatic activity of TST hydroxylases, resulting in increased hepatic TST catabolism. These findings suggest that subchronic MPH exposure in adolescent rats could have a trophic action on testis growth and a negative impact on TST metabolism. We have analyzed striatal gene expression profiles as a consequence of MPH exposure during adolescence, using microarray technology. More than 700 genes were upregulated in the striatum of MPH-treated rats (foldchange >1.5). A first group of genes were apparently involved in migration of immature neural/glial cells and/or growth of novel axons. These genes include matrix proteases (ADAM-1, MMP14), their inhibitors (TIMP-2, TIMP-3), the hyaluronan-mediated motility receptor (RHAMM), and growth factors (transforming growth factor-beta3 [TGF-beta3] and fibroblast growth factor 14 [FGF14]). A second group of genes were suggestive of active axonal myelination. These genes mediate survival of immature cells after contact with newly produced axonal matrix (laminin B1, collagens, integrin alpha 6) and stabilization of myelinating glia-axon contacts (RAB13, contactins 3 and 4). A third group indicated the appearance and/or upregulation of mature processes. The latter included genes for: K+ channels (TASK-1, TASK-5), intercellular junctions (connexin30), neurotransmitter receptors (adrenergic alpha 1B, kainate 2, serotonin 7, GABA-A), as well as major proteins responsible for their transport and/or anchoring (Homer 1, MAGUK MPP3, Shank2). All these genes were possibly involved in synaptic plasticity, namely the formation, maturation, and stabilization of new neural connections within the striatum. MPH treatment seems to potentiate synaptic plasticity, which is an age-dependent developmental phenomenon that adolescent rats are very likely to show, compared to adults. Our observations suggest that adolescent MPH exposure causes only transient changes in reproductive and hormonal parameters, and a more enduring enhancement of neurobehavioral plasticity.
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Affiliation(s)
- Walter Adriani
- Department of Cell Biology & Neurosciences, Behavioural Neuroscience Section, Istituto Superiore di Sanità, viale Regina Elena 299, I-00161 Roma, Italy.
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22
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Sinha K, Karimi-Abdolrezaee S, Velumian AA, Fehlings MG. Functional Changes in Genetically Dysmyelinated Spinal Cord Axons ofShivererMice: Role of Juxtaparanodal Kv1 Family K+Channels. J Neurophysiol 2006; 95:1683-95. [PMID: 16319208 DOI: 10.1152/jn.00899.2005] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Axonal dysfunction after spinal cord injury (SCI) and other types of neurotrauma is associated with demyelination and exposure of juxtaparanodal K+channels. In this study, sucrose gap electrophysiology using selective and nonselective K+channel blockers, confocal immunohistochemistry, and Western blotting were used to study the role of Kv1.1 and Kv1.2 K+channel subunits in dysmyelination-induced spinal cord axonal dysfunction in s hiverer mice, which lack the gene encoding myelin basic protein (MBP) and exhibit incomplete myelin sheath formation on CNS axons. The s hiverer spinal cord axons exhibited smaller amplitude of compound action potentials (CAPs), reduced conduction velocity, reduced excitability, and greater degree of high-frequency conduction failure. The “fast” K+channel blocker 4-aminopyridine, the toxin DTX-I, which targets the Kv1.1 and Kv1.2, but not DTX- K, which has higher selectivity for Kv1.1, increased the amplitude and area of CAPs of shiverer mice spinal cord axons but had insignificant effects in wild-type mice. Confocal immunohistochemistry showed that, unlike wild-type mice, which have a precise juxtaparanodal localization of the Kv1.l and Kv1.2 K+channel subunits, shiverer mouse axons displayed a dispersed distribution of these subunits along the internodes. In contrast, the Kv1.l and Kv1.2 subunits, Na+channels remained highly localized to the nodal regions. Western blotting showed an increased expression of Kv 1.1 and 1.2 in the shiverer mouse spinal cord. These results provide evidence that the neurological deficits associated with myelin deficiency reflect the altered distribution and expression of the K+channel subunits Kv1.l and Kv1.2 along the internodes of spinal cord axons associated with the biophysical consequences caused by alterations in the myelin sheaths.
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Affiliation(s)
- Kusum Sinha
- Div. of Cell and Molecular Biology, Univ. of Toronto, Toronto Western Hospital, Univ. Health Network, Rm. 4W-449, 399 Bathurst St., Toronto, Ontario M5T 2S8, Canada
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23
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Eshed Y, Feinberg K, Poliak S, Sabanay H, Sarig-Nadir O, Spiegel I, Bermingham JR, Peles E. Gliomedin Mediates Schwann Cell-Axon Interaction and the Molecular Assembly of the Nodes of Ranvier. Neuron 2005; 47:215-29. [PMID: 16039564 DOI: 10.1016/j.neuron.2005.06.026] [Citation(s) in RCA: 239] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2005] [Revised: 05/16/2005] [Accepted: 06/26/2005] [Indexed: 01/06/2023]
Abstract
Accumulation of Na(+) channels at the nodes of Ranvier is a prerequisite for saltatory conduction. In peripheral nerves, clustering of these channels along the axolemma is regulated by myelinating Schwann cells through a yet unknown mechanism. We report the identification of gliomedin, a glial ligand for neurofascin and NrCAM, two axonal immunoglobulin cell adhesion molecules that are associated with Na+ channels at the nodes of Ranvier. Gliomedin is expressed by myelinating Schwann cells and accumulates at the edges of each myelin segment during development, where it aligns with the forming nodes. Eliminating the expression of gliomedin by RNAi, or the addition of a soluble extracellular domain of neurofascin to myelinating cultures, which caused the redistribution of gliomedin along the internodes, abolished node formation. Furthermore, a soluble gliomedin induced nodal-like clusters of Na+ channels in the absence of Schwann cells. We propose that gliomedin provides a glial cue for the formation of peripheral nodes of Ranvier.
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MESH Headings
- Age Factors
- Amino Acid Sequence
- Animals
- Ankyrins/metabolism
- Axons/metabolism
- Blotting, Northern/methods
- Blotting, Western/methods
- Cell Adhesion Molecules/immunology
- Cell Adhesion Molecules/metabolism
- Cell Adhesion Molecules, Neuronal/metabolism
- Cell Compartmentation
- Cells, Cultured
- Chlorocebus aethiops
- Claudins
- Cloning, Molecular/methods
- Cytoskeletal Proteins
- Fluorescent Antibody Technique/methods
- Ganglia, Spinal/metabolism
- Gene Expression Regulation, Developmental
- Humans
- Macromolecular Substances/immunology
- Macromolecular Substances/metabolism
- Membrane Proteins/metabolism
- Microfilament Proteins/metabolism
- Microscopy, Immunoelectron/methods
- Myelin Basic Protein/metabolism
- Myelin-Associated Glycoprotein/metabolism
- Neurofilament Proteins/metabolism
- Phosphoproteins/metabolism
- Protein Binding/physiology
- Protein Structure, Tertiary
- Ranvier's Nodes/metabolism
- Ranvier's Nodes/ultrastructure
- Rats
- Receptors, Peptide/metabolism
- S100 Proteins/metabolism
- Schwann Cells/metabolism
- Schwann Cells/ultrastructure
- Sciatic Nerve/growth & development
- Sciatic Nerve/metabolism
- Sodium Channels/metabolism
- Spectrin/metabolism
- Transfection/methods
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Affiliation(s)
- Yael Eshed
- Department of Molecular Cell Biology, The Weizmann Institute of Science, Rehovot 76100, Israel
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24
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Eftekharpour E, Karimi-Abdolrezaee S, Sinha K, Velumian AA, Kwiecien JM, Fehlings MG. Structural and functional alterations of spinal cord axons in adult Long Evans Shaker (LES) dysmyelinated rats. Exp Neurol 2005; 193:334-49. [PMID: 15869936 DOI: 10.1016/j.expneurol.2005.01.019] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2004] [Revised: 01/07/2005] [Accepted: 01/19/2005] [Indexed: 12/20/2022]
Abstract
Abnormal formation or loss of myelin is a distinguishing feature of many neurological disorders and contributes to the pathobiology of neurotrauma. In this study we characterize the functional and molecular changes in CNS white matter in Long Evans Shaker (LES) rats. These rats have a spontaneous mutation of the gene encoding myelin basic protein which results in severe dysmyelination of the central nervous system (CNS), providing a unique model for demyelinating/dysmyelinating disorders. To date, the functional and molecular changes in CNS white matter in this model are not well understood. We have used in vivo somatosensory evoked potential (SSEP), in vitro compound action potential (CAP) recording in isolated dorsal columns, confocal immunohistochemistry, Western blotting and real-time PCR to examine the electrophysiological, molecular and cellular changes in spinal cord white matter in LES rats. We observed that dysmyelination is associated with dispersed labeling of Kv1.1 and Kv1.2 K+ channel subunits, as well as Caspr, a protein normally confined to paranodes, along the LES rat spinal cord axons. Abnormal electrophysiological properties including attenuation of CAP amplitude and conduction velocity, high frequency conduction failure and enhanced sensitivity to K+ channel blockers 4-aminopyridine and dendrotoxin-I were observed in spinal cord axons from LES rats. Our results in LES rats clarify some of the key molecular, cellular and functional consequences of dysmyelination and myelin-axon interactions. Further understanding of these issues in this model could provide critical insights for neurological disorders characterized by demyelination.
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MESH Headings
- Action Potentials/drug effects
- Action Potentials/physiology
- Action Potentials/radiation effects
- Analysis of Variance
- Animals
- Axons/metabolism
- Axons/physiology
- Blotting, Western/methods
- Cell Adhesion Molecules, Neuronal/genetics
- Cell Adhesion Molecules, Neuronal/metabolism
- Dose-Response Relationship, Radiation
- Electric Stimulation/methods
- Evoked Potentials, Somatosensory/physiology
- Immunohistochemistry/methods
- In Vitro Techniques
- Kv1.1 Potassium Channel
- Kv1.2 Potassium Channel
- Myelin Basic Protein/genetics
- Myelin Basic Protein/metabolism
- Neural Conduction/physiology
- Neural Conduction/radiation effects
- Neurofilament Proteins/metabolism
- Peptides/pharmacology
- Potassium Channel Blockers/pharmacology
- Potassium Channels, Voltage-Gated/genetics
- Potassium Channels, Voltage-Gated/metabolism
- Pyrimidines/pharmacology
- RNA, Messenger/biosynthesis
- Rats
- Rats, Long-Evans
- Rats, Mutant Strains/genetics
- Rats, Mutant Strains/physiology
- Reverse Transcriptase Polymerase Chain Reaction/methods
- Spinal Cord/drug effects
- Spinal Cord/metabolism
- Spinal Cord/physiopathology
- Spinal Cord/radiation effects
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Affiliation(s)
- Eftekhar Eftekharpour
- Division of Cell and Molecular Biology, Toronto Western Research Institute, Krembil Neuroscience Center, McMaster University, Hamilton, Canada
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25
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Arroyo EJ, Sirkowski EE, Chitale R, Scherer SS. Acute demyelination disrupts the molecular organization of peripheral nervous system nodes. J Comp Neurol 2005; 479:424-34. [PMID: 15514980 DOI: 10.1002/cne.20321] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Intraneurally injected lysolecithin causes both segmental and paranodal demyelination. In demyelinated internodes, axonal components of nodes fragment and disappear, glial and axonal paranodal and juxtaparanodal proteins no longer cluster, and axonal Kv1.1/Kv1.2 K+ channels move from the juxtaparanodal region to appose the remaining heminodes. In paranodal demyelination, a gap separates two distinct heminodes, each of which contains the molecular components of normal nodes; paranodal and juxtaparanodal proteins are properly localized. As in normal nodes, widened nodal regions contain little or no band 4.1B. Lysolecithin also causes "unwinding" of paranodes: The spiral of Schwann cell membrane moves away from the paranodes, but the glial and axonal components of septate-like junctions remain colocalized. Thus, acute demyelination has distinct effects on the molecular organization of the nodal, paranodal, and juxtaparanodal region, reflecting altered axon-Schwann cell interactions.
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Affiliation(s)
- Edgardo J Arroyo
- Department of Neurology, The University of Pennsylvania Medical Center, Philadelphia, Pennsylvania 19104-6077, USA.
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26
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Abstract
Multiple sclerosis (MS) is the most common cause of neurological disability in young adults. The pathological hallmark is multifocal demyelination and inflammation in the CNS. In addition, there is also a variable extent of axonal damage. Remyelination has been seen in up to 70% of lesions but repair is generally incomplete. The demonstration of neuropathological heterogeneity of MS lesions suggests different pathophysiological subtypes and it is therefore unlikely that there is a uniform cause of incomplete remyelination in MS. In recent years, a great body of knowledge has accumulated in order to better understand the regulatory mechanisms of remyelination. This has led to a number of approaches to promote repair mechanisms, most of which have been successful in animal experiments. Unfortunately, the translation of these experimental data into clinical treatments has proven difficult. More information on the pathogenesis of MS, the reason why repair mechanisms fail in MS and a better understanding of the regulation of remyelination are required. This will ultimately lead to a specific treatment tailored for the individual patient and will probably involve a combination of immunomodulation, remyelination and neuroprotection.
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Affiliation(s)
- Martin Stangel
- Department of Neurology, Medical School Hannover, Germany.
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27
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Abstract
The central concept underlying ideas on the pathogenesis of multiple sclerosis is that inflammatory events cause acute injury of axons and myclin. The phases of symptom onset, recovery, persistence, and progression in multiple sclerosis can be summarized as functional impairment with intact structure due to direct effects of inflammatory mediators; demyelination and axonal injury with recovery through plasticity and remyelination; and chronic axonal loss due to failure of enduring remyelination from loss of trophic support for axons normally provided by cells of the oligodendrocyte lineage. Cell death may occur in response to a state of injury from which protection would be anticipated under more favourable neurobiological conditions. Conversely, optimal growth factor environment may save cells from otherwise lethal events occurring at the cell membrane. Hence, in the context of brain inflammation, there is an inseparable interplay between immunological and neurobiological contributions to tissue injury.
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Affiliation(s)
- A Compston
- Department of Clinical Neurosciences, University of Cambridge, Clinical School, Addenbrooke's Hospital, Hills Road, Cambridge, UK.
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28
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Takikita S, Fukuda T, Mohri I, Yagi T, Suzuki K. Perturbed myelination process of premyelinating oligodendrocyte in Niemann-Pick type C mouse. J Neuropathol Exp Neurol 2004; 63:660-73. [PMID: 15217094 DOI: 10.1093/jnen/63.6.660] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Niemann-Pick disease type C (NPC) is an autosomal recessive neurovisceral lipid storage disease caused by a loss of NPCI function, which results in perturbation of intracellular cholesterol transport. In BALB/c npc(nih) mice, the murine ortholog of NPCI gene is mutated. In NPC mouse, hypomyelination is conspicuous in the cerebral white matter and corpus callosum in addition to neuronal storage. However, the pathogenesis on hypomyelination is not well elucidated. We hypothesized that the hypomyelination in NPC mice resulted from either defective differentiation of oligodendrocyte lineage cells or a failure of proper axon-glial interaction. Myelin basic protein immunohistochemistry disclosed severe hypomyelination of cerebral cortex as well. NG2- or O4-positive progenitor cells and premyelinating oligodendrocytes (OLs) were abundant. However, pi-glutathione-S-transferase-positive mature OLs were considerably reduced. In hypomyelinated white matter, strong immunoreactivity of polysialylated-neural cell adhesion molecule, a negative regulator of myelination, was observed in axons. Given the fact that neuro-axonal degeneration has been observed in NPC mouse as early as 9 days of age prior to the commencement of myelination in the corpus callosum and that axonal signals are essential for the proper myelination, subtle axonal injury might be contributing to the pathogenesis of disturbed myelination in the NPC mouse.
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Affiliation(s)
- Shoichi Takikita
- Department of Pathology and Laboratory Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-7525, USA
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29
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Menon K, Rasband MN, Taylor CM, Brophy P, Bansal R, Pfeiffer SE. The myelin-axolemmal complex: biochemical dissection and the role of galactosphingolipids. J Neurochem 2004; 87:995-1009. [PMID: 14622129 DOI: 10.1046/j.1471-4159.2003.02075.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Myelin-axolemmal interactions regulate many cellular and molecular events, including gene expression, oligodendrocyte survival and ion channel clustering. Here we report the biochemical fractionation and enrichment of distinct subcellular domains from myelinated nerve fibers. Using antibodies against proteins found in compact myelin, non-compact myelin and axolemma, we show that a rigorous procedure designed to purify myelin also results in the isolation of the myelin-axolemmal complex, a high-affinity protein complex consisting of axonal and oligodendroglial components. Further, the isolation of distinct subcellular domains from galactolipid-deficient mice with disrupted axoglial junctions is altered in a manner consistent with the delocalization of axolemmal proteins observed in these animals. These results suggest a paradigm for identification of proteins involved in neuroglial signaling.
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Affiliation(s)
- Krishna Menon
- Department of Neuroscience, University of Connecticut Medical School, Farmington, Connecticut 06030-3401, USA
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30
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Abstract
Efficient and rapid propagation of action potentials in myelinated axons depends on the molecular specialization of the nodes of Ranvier. The nodal region is organized into several distinct domains, each of which contains a unique set of ion channels, cell-adhesion molecules and cytoplasmic adaptor proteins. Voltage-gated Na+ channels - which are concentrated at the nodes - are separated from K+ channels - which are clustered at the juxtaparanodal region - by a specialized axoglial contact that is formed between the axon and the myelinating cell at the paranodes. This local differentiation of myelinated axons is tightly regulated by oligodendrocytes and myelinating Schwann cells, and is achieved through complex mechanisms that are used by another specialized cell-cell contact - the synapse.
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Affiliation(s)
- Sebastian Poliak
- Department of Molecular Cell Biology, The Weizmann Institute of Science, Rehovot, Israel
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31
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Abstract
The entire length of myelinated axons is organized into a series of polarized domains that center around nodes of Ranvier. These domains, which are crucial for normal saltatory conduction, consist of distinct multiprotein complexes of cell adhesion molecules, ion channels, and scaffolding molecules; they also differ in their diameter, organelle content, and rates of axonal transport. Juxtacrine signals from myelinating glia direct their sequential assembly. The composition, mechanisms of assembly, and function of these molecular domains will be reviewed. I also discuss similarities of this domain organization to that of polarized epithelia and present emerging evidence that disorders of domain organization and function contribute to the axonopathies of myelin and other neurologic disorders.
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Affiliation(s)
- James L Salzer
- Department of Cell Biology and Neurology, Program in Molecular Neurobiology, Skirball Institute of Biomedical Research, New York University School of Medicine, 540 First Avenue, New York, NY 10016, USA.
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Traka M, Goutebroze L, Denisenko N, Bessa M, Nifli A, Havaki S, Iwakura Y, Fukamauchi F, Watanabe K, Soliven B, Girault JA, Karagogeos D. Association of TAG-1 with Caspr2 is essential for the molecular organization of juxtaparanodal regions of myelinated fibers. J Cell Biol 2003; 162:1161-72. [PMID: 12975355 PMCID: PMC2172849 DOI: 10.1083/jcb.200305078] [Citation(s) in RCA: 195] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Myelination results in a highly segregated distribution of axonal membrane proteins at nodes of Ranvier. Here, we show the role in this process of TAG-1, a glycosyl-phosphatidyl-inositol-anchored cell adhesion molecule. In the absence of TAG-1, axonal Caspr2 did not accumulate at juxtaparanodes, and the normal enrichment of shaker-type K+ channels in these regions was severely disrupted, in the central and peripheral nervous systems. In contrast, the localization of protein 4.1B, an axoplasmic partner of Caspr2, was only moderately altered. TAG-1, which is expressed in both neurons and glia, was able to associate in cis with Caspr2 and in trans with itself. Thus, a tripartite intercellular protein complex, comprised of these two proteins, appears critical for axo-glial contacts at juxtaparanodes. This complex is analogous to that described previously at paranodes, suggesting that similar molecules are crucial for different types of axo-glial interactions.
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Affiliation(s)
- Maria Traka
- Department of Basic Science, University of Crete Medical School, Heraklion 71110, Crete, Greece
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33
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Abstract
The developing nervous system has been long recognized as a primary target for a variety of toxicants. To date, most efforts to understand the impact of neurotoxic agents on the brain have focused primarily on neurons and to a lesser degree astroglia as cellular targets. The role of oligodendroglia, the myelin-forming cells in the central nervous system (CNS), in developmental neurotoxicity has been emphasized only in recent years. Oligodendrocytes originate from migratory, mitotic progenitors that mature progressively into postmitotic myelinating cells. During differentiation, oligodendroglial lineage cells pass through a series of distinct phenotypic stages that are characterized by different proliferative capacities and migratory abilities, as well as dramatic changes in morphology with sequential expression of unique developmental markers. In recent years, it has become appreciated that oligodendrocyte lineage cells have important functions other than those related to myelin formation and maintenance, including participation in neuronal survival and development, as well as neurotransmission and synaptic function. Substantial knowledge has accumulated on the control of oligodendroglial survival, migration, proliferation, and differentiation, as well as the cellular and molecular events involved in oligodendroglial development and myelin formation. Recently, studies have been initiated to address the role of oligodendrocyte lineage cells in neurotoxic processes. This article examines recent progress in oligodendroglial biology, focuses attention on the characteristic features of the oligodendrocyte developmental lineage as a model system for neurotoxicological studies, and explores the role of oligodendrocyte lineage cells in developmental neurotoxicity. The potential role of oligodendroglia in environmental lead neurotoxicity is presented to exemplify this thesis.
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Affiliation(s)
- Wenbin Deng
- Department of Biochemistry and Microbiology, Rutgers University, 76 Lipman Drive, New Brunswick, NJ 08901-8525, USA
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Denisenko-Nehrbass N, Oguievetskaia K, Goutebroze L, Galvez T, Yamakawa H, Ohara O, Carnaud M, Girault JA. Protein 4.1B associates with both Caspr/paranodin and Caspr2 at paranodes and juxtaparanodes of myelinated fibres. Eur J Neurosci 2003; 17:411-6. [PMID: 12542678 DOI: 10.1046/j.1460-9568.2003.02441.x] [Citation(s) in RCA: 112] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Caspr/paranodin, a neuronal transmembrane glycoprotein, is essential for the structure and function of septate-like paranodal axoglial junctions at nodes of Ranvier. A closely related protein, Caspr2, is concentrated in juxtaparanodal regions where it associates indirectly with the shaker-type potassium channels. Although ultrastructural studies indicate that paranodal complexes are linked to the cytoskeleton, the intracellular partners of Caspr/paranodin, as well as those of Caspr2, are poorly characterized. We show that the conserved intracellular juxtamembrane regions (GNP motif) of Caspr/paranodin and Caspr2 bind proteins 4.1R and 4.1B. 4.1B is known to be enriched in paranodal and juxtaparanodal regions. 4.1B immunoreactivity accumulates progressively at paranodes and juxtaparanodes during postnatal development, following the concentration of Caspr/paranodin and Caspr2, respectively, in central and peripheral myelinated axons. These two proteins coimmunoprecipitated with 4.1B in brain homogenates. Our results provide strong evidence for the association of 4.1B with Caspr/paranodin at paranodes and with Caspr2 at juxtaparanodes. We propose that 4.1B anchors these axonal proteins to the actin-based cytoskeleton in these two regions.
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35
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Denisenko-Nehrbass N, Goutebroze L, Galvez T, Bonnon C, Stankoff B, Ezan P, Giovannini M, Faivre-Sarrailh C, Girault JA. Association of Caspr/paranodin with tumour suppressor schwannomin/merlin and beta1 integrin in the central nervous system. J Neurochem 2003; 84:209-21. [PMID: 12558984 DOI: 10.1046/j.1471-4159.2003.01503.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Caspr/paranodin is an essential neuronal component of paranodal axoglial junctions, associated with contactin/F3. Its short intracellular domain contains a conserved motif (GNP motif) capable of binding protein 4.1 domains [FERM domains (four point one, ezrin, radixin, moesin)]. Schwannomin/merlin is a tumour suppressor expressed in many cell types, including in neurons, the function and partners of which are still poorly characterized. We show that the FERM domain of schwannomin binds to the paranodin GNP motif in glutathione S-transferase (GST)-pull down assays and in transfected COS-7 cells. The two proteins co-immunoprecipitated in brain extracts. In addition, paranodin and schwannomin were associated with integrin beta1 in transfected cells and in brain homogenates. The presence of paranodin increased the association between integrin beta1 and schwannomin or its N-terminal domain, suggesting that the interactions between these proteins are interdependent. In jimpy mutant mice, which display a severe dysmyelination with deficient paranodal junctions, the interactions between paranodin, schwannomin and integrin beta1 were profoundly altered. Our results show that schwannomin and integrin beta1 can be associated with paranodin in the central nervous system. Since integrin beta1 and schwannomin do not appear to be enriched in paranodes they may be quantitatively minor partners of paranodin in these regions and/or be associated with paranodin at other locations.
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Abstract
Demyelination is the pathological hallmark of multiple sclerosis (MS) lesions. The concept of remyelination has gained acceptance in recent years, but naturally occurring remyelination is incomplete. To improve repair processes, a number of strategies have been explored experimentally and clinical trials are being carried out. In principle, remyelination can be achieved by either promoting endogenous repair mechanisms or by providing an exogenous source of myelinating cells via transplantation. Both approaches have been successful in animal models of demyelination. Besides, many studies have elucidated principal mechanisms of oligodendrocyte biology and remyelination in the central nervous system (CNS). This progress in knowledge also allowed for more specific interventions. First clinical trials to enhance endogenous remyelination have been performed, unfortunately with disappointingly negative results. This illustrates that experimental data cannot be easily transferred to human disease, and more detailed knowledge on the regulatory mechanisms of remyelination in MS is required. Recently, the first MS patient received a transplant of autologous Schwann cells. Many other cell types are being studied experimentally, including stem cells. Despite the ethical problems associated with an embryonic cell source, new developments in stem cell biology indicate that adult stem cells or bone marrow-derived cells may substitute for embryonic cells in the future. In this review, we describe the current views on oligodendrocyte biology, myelination and remyelination, and focus on recent developments leading to reconstructing, remyelinating strategies in MS.
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Affiliation(s)
- Martin Stangel
- Department of Neurology, Medical School Hannover OE 7210, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany.
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37
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Abstract
The architecture and function of the nodes of Ranvier depend on several specialized cell contacts between the axon and myelinating glial cells. These sites contain highly organized multimolecular complexes of ion channels and cell adhesion molecules, closely connected with the cytoskeleton. Recent findings are beginning to reveal how this organization is achieved during the development of myelinated nerves. The role of membrane proteins involved in axoglial interactions and of associated cytoplasmic molecules is being elucidated, while studies of mutant mice have underlined the importance of glial cells and the specific role of axonal proteins in the organization of axonal domains.
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Affiliation(s)
- Jean-Antoine Girault
- INSERM U 536, Institut du Fer à Moulin, 17 rue du Fer à Moulin, 75005 Paris, France.
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