1
|
Bai G, Bai Y, Guan H, Ren H, Li H, Wang Y. A case report of lymphoproliferative disease in brain following therapies with mycophenolate Mofetil and Fingolimod and literature review. J Neuroimmunol 2024; 394:578410. [PMID: 39067241 DOI: 10.1016/j.jneuroim.2024.578410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Revised: 06/17/2024] [Accepted: 07/21/2024] [Indexed: 07/30/2024]
Abstract
Anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis is an autoimmune disorder. With the method of indirect immunofluorescence assay (IIF), more anti-NMDAR encephalitis patients have been discovered when its first onset. But it was rare that anti-NMDAR encephalitis overlapped with multiple sclerosis (MS) documented in literatures. Here, we present a case who initially developed anti-NMDAR encephalitis and MS. Furthermore, we concluded the characteristics of patients who were diagnosed as anti-NMDAR encephalitis overlapping with MS. Additionally, due to the relapsing process, mycophenolate mofetil and sequentially fingolimod for the treatment were taken, which subsequently led to the development of a lymphoproliferative disease in his brain and other organs. This case illustrates the complex role of immunosuppressive agents.
Collapse
Affiliation(s)
- Ge Bai
- Department of Neurology, Tangshan People's Hospital, Tangshan, Hebei Province, China.
| | - Ying Bai
- Department of Gastroenterology, Tangshan People 's Hospital, Tang Shan, Hebei Province, China
| | - Hongzhi Guan
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Haitao Ren
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Haifeng Li
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Yan Wang
- Department of Neurology, Tangshan People's Hospital, Tangshan, Hebei Province, China
| |
Collapse
|
2
|
D'Egidio F, Castelli V, d'Angelo M, Ammannito F, Quintiliani M, Cimini A. Brain incoming call from glia during neuroinflammation: Roles of extracellular vesicles. Neurobiol Dis 2024:106663. [PMID: 39251030 DOI: 10.1016/j.nbd.2024.106663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2024] [Revised: 09/04/2024] [Accepted: 09/06/2024] [Indexed: 09/11/2024] Open
Abstract
The functionality of the central nervous system (CNS) relies on the connection, integration, and the exchange of information among neural cells. The crosstalk among glial cells and neurons is pivotal for a series of neural functions, such as development of the nervous system, electric conduction, synaptic transmission, neural circuit establishment, and brain homeostasis. Glial cells are crucial players in the maintenance of brain functionality in physiological and disease conditions. Neuroinflammation is a common pathological process in various brain disorders, such as neurodegenerative diseases, and infections. Glial cells, including astrocytes, microglia, and oligodendrocytes, are the main mediators of neuroinflammation, as they can sense and respond to brain insults by releasing pro-inflammatory or anti-inflammatory factors. Recent evidence indicates that extracellular vesicles (EVs) are pivotal players in the intercellular communication that underlies physiological and pathological processes. In particular, glia-derived EVs play relevant roles in modulating neuroinflammation, either by promoting or inhibiting the activation of glial cells and neurons, or by facilitating the clearance or propagation of pathogenic proteins. The involvement of EVs in neurodegenerative diseases such as Alzheimer's Disease (AD), Parkinson's Disease (PD), Huntington's Disease (HD), and Multiple Sclerosis (MS)- which share hallmarks such as neuroinflammation and oxidative stress to DNA damage, alterations in neurotrophin levels, mitochondrial impairment, and altered protein dynamics- will be dissected, showing how EVs act as pivotal cell-cell mediators of toxic stimuli, thereby propagating degeneration and cell death signaling. Thus, this review focuses on the EVs secreted by microglia, astrocytes, oligodendrocytes and in neuroinflammatory conditions, emphasizing on their effects on neurons and on central nervous system functions, considering both their beneficial and detrimental effects.
Collapse
Affiliation(s)
- Francesco D'Egidio
- Department of Life, Health and Environmental Sciences, University of L'Aquila, Italy 67100, Via Vetoio - Coppito1, Building "Renato Ricamo"
| | - Vanessa Castelli
- Department of Life, Health and Environmental Sciences, University of L'Aquila, Italy 67100, Via Vetoio - Coppito1, Building "Renato Ricamo"
| | - Michele d'Angelo
- Department of Life, Health and Environmental Sciences, University of L'Aquila, Italy 67100, Via Vetoio - Coppito1, Building "Renato Ricamo".
| | - Fabrizio Ammannito
- Department of Life, Health and Environmental Sciences, University of L'Aquila, Italy 67100, Via Vetoio - Coppito1, Building "Renato Ricamo"
| | - Massimiliano Quintiliani
- Department of Life, Health and Environmental Sciences, University of L'Aquila, Italy 67100, Via Vetoio - Coppito1, Building "Renato Ricamo"
| | - Annamaria Cimini
- Department of Life, Health and Environmental Sciences, University of L'Aquila, Italy 67100, Via Vetoio - Coppito1, Building "Renato Ricamo"
| |
Collapse
|
3
|
Stys PK, Tsutsui S, Gafson AR, ‘t Hart BA, Belachew S, Geurts JJG. New views on the complex interplay between degeneration and autoimmunity in multiple sclerosis. Front Cell Neurosci 2024; 18:1426231. [PMID: 39161786 PMCID: PMC11330826 DOI: 10.3389/fncel.2024.1426231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2024] [Accepted: 06/14/2024] [Indexed: 08/21/2024] Open
Abstract
Multiple sclerosis (MS) is a frequently disabling neurological disorder characterized by symptoms, clinical signs and imaging abnormalities that typically fluctuate over time, affecting any level of the CNS. Prominent lymphocytic inflammation, many genetic susceptibility variants involving immune pathways, as well as potent responses of the neuroinflammatory component to immunomodulating drugs, have led to the natural conclusion that this disease is driven by a primary autoimmune process. In this Hypothesis and Theory article, we discuss emerging data that cast doubt on this assumption. After three decades of therapeutic experience, what has become clear is that potent immune modulators are highly effective at suppressing inflammatory relapses, yet exhibit very limited effects on the later progressive phase of MS. Moreover, neuropathological examination of MS tissue indicates that degeneration, CNS atrophy, and myelin loss are most prominent in the progressive stage, when lymphocytic inflammation paradoxically wanes. Finally, emerging clinical observations such as "progression independent of relapse activity" and "silent progression," now thought to take hold very early in the course, together argue that an underlying "cytodegenerative" process, likely targeting the myelinating unit, may in fact represent the most proximal step in a complex pathophysiological cascade exacerbated by an autoimmune inflammatory overlay. Parallels are drawn with more traditional neurodegenerative disorders, where a progressive proteopathy with prion-like propagation of toxic misfolded species is now known to play a key role. A potentially pivotal contribution of the Epstein-Barr virus and B cells in this process is also discussed.
Collapse
Affiliation(s)
- Peter K. Stys
- Department of Clinical Neurosciences, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Shigeki Tsutsui
- Department of Clinical Neurosciences, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Arie R. Gafson
- Biogen Digital Health, Biogen, Cambridge, MA, United States
| | - Bert A. ‘t Hart
- Department of Anatomy and Neurosciences, Amsterdam University Medical Centers (location VUmc), Amsterdam, Netherlands
| | - Shibeshih Belachew
- TheraPanacea, Paris, France
- Indivi (DBA of Healios AG), Basel, Switzerland
| | - Jeroen J. G. Geurts
- Department of Anatomy and Neurosciences, Amsterdam University Medical Centers (location VUmc), Amsterdam, Netherlands
| |
Collapse
|
4
|
Barbaresi P, Fabri M, Lorenzi T, Sagrati A, Morroni M. Intrinsic organization of the corpus callosum. Front Physiol 2024; 15:1393000. [PMID: 39035452 PMCID: PMC11259024 DOI: 10.3389/fphys.2024.1393000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Accepted: 05/16/2024] [Indexed: 07/23/2024] Open
Abstract
The corpus callosum-the largest commissural fiber system connecting the two cerebral hemispheres-is considered essential for bilateral sensory integration and higher cognitive functions. Most studies exploring the corpus callosum have examined either the anatomical, physiological, and neurochemical organization of callosal projections or the functional and/or behavioral aspects of the callosal connections after complete/partial callosotomy or callosal lesion. There are no works that address the intrinsic organization of the corpus callosum. We review the existing information on the activities that take place in the commissure in three sections: I) the topographical and neurochemical organization of the intracallosal fibers, II) the role of glia in the corpus callosum, and III) the role of the intracallosal neurons.
Collapse
Affiliation(s)
- Paolo Barbaresi
- Department of Experimental and Clinical Medicine, Section of Neuroscience and Cell Biology, Marche Polytechnic University, Ancona, Italy
| | - Mara Fabri
- Department of Life and Environmental Sciences, Marche Polytechnic University, Ancona, Italy
| | - Teresa Lorenzi
- Department of Experimental and Clinical Medicine, Section of Neuroscience and Cell Biology, Marche Polytechnic University, Ancona, Italy
| | - Andrea Sagrati
- Department of Life and Environmental Sciences, Marche Polytechnic University, Ancona, Italy
| | - Manrico Morroni
- Electron Microscopy Unit, Azienda Ospedaliero-Universitaria, Ancona, Italy
| |
Collapse
|
5
|
Peterson BS, Li J, Trujillo M, Sawardekar S, Balyozian D, Bansal S, Sun BF, Marcelino C, Nanda A, Xu T, Amen D, Bansal R. A multi-site 99mTc-HMPAO SPECT study of cerebral blood flow in a community sample of patients with major depression. Transl Psychiatry 2024; 14:234. [PMID: 38830866 PMCID: PMC11148018 DOI: 10.1038/s41398-024-02961-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 05/09/2024] [Accepted: 05/23/2024] [Indexed: 06/05/2024] Open
Abstract
Prior regional Cerebral Blood Flow (rCBF) studies in Major Depressive Disorder (MDD) have been limited by small, highly selective, non-representative samples that have yielded variable and poorly replicated findings. The aim of this study was to compare rCBF measures in a large, more representative community sample of adults with MDD and healthy control participants. This is a cross-sectional, retrospective multi-site cohort study in which clinical data from 338 patients 18-65 years of age with a primary diagnosis of MDD were retrieved from a central database for 8 privately owned, private-pay outpatient psychiatric centers across the United States. Two 99mTc-HMPAO SPECT brain scans, one at rest and one during performance of a continuous performance task, were acquired as a routine component of their initial clinical evaluation. In total, 103 healthy controls, 18-65 years old and recruited from the community were also assessed and scanned. Depressed patients had significantly higher rCBF in frontal, anterior cingulate, and association cortices, and in basal ganglia, thalamus, and cerebellum, after accounting for significantly higher overall CBF. Depression severity associated positively with rCBF in the basal ganglia, hippocampus, cerebellum, and posterior white matter. Elevated rCBF was especially prominent in women and older patients. Elevated rCBF likely represents pathogenic hypermetabolism in MDD, with its magnitude in direct proportion to depression severity. It is brain-wide, with disproportionate increases in cortical and subcortical attentional networks. Hypermetabolism may be a reasonable target for novel therapeutics in MDD.
Collapse
Affiliation(s)
- Bradley S Peterson
- Institute for the Developing Mind, Children's Hospital Los Angeles, Los Angeles, CA, USA.
- Department of Psychiatry, Keck School of Medicine at the University of Southern California, Los Angeles, CA, USA.
| | - Jennifer Li
- Institute for the Developing Mind, Children's Hospital Los Angeles, Los Angeles, CA, USA
- Department of Psychiatry, Keck School of Medicine at the University of Southern California, Los Angeles, CA, USA
| | - Manuel Trujillo
- Department of Psychiatry at NYU Grossman School of Medicine, New York, NY, USA
- Amen Clinics Inc., Costa Mesa, CA, USA
| | - Siddhant Sawardekar
- Institute for the Developing Mind, Children's Hospital Los Angeles, Los Angeles, CA, USA
| | - David Balyozian
- Department of Psychiatry, Keck School of Medicine at the University of Southern California, Los Angeles, CA, USA
| | - Siddharth Bansal
- Institute for the Developing Mind, Children's Hospital Los Angeles, Los Angeles, CA, USA
| | - Bernice F Sun
- Institute for the Developing Mind, Children's Hospital Los Angeles, Los Angeles, CA, USA
| | - Courtney Marcelino
- Institute for the Developing Mind, Children's Hospital Los Angeles, Los Angeles, CA, USA
| | - Anoop Nanda
- Institute for the Developing Mind, Children's Hospital Los Angeles, Los Angeles, CA, USA
| | - Tracy Xu
- Institute for the Developing Mind, Children's Hospital Los Angeles, Los Angeles, CA, USA
| | | | - Ravi Bansal
- Institute for the Developing Mind, Children's Hospital Los Angeles, Los Angeles, CA, USA
- Department of Psychiatry, Keck School of Medicine at the University of Southern California, Los Angeles, CA, USA
| |
Collapse
|
6
|
Khelfaoui H, Ibaceta-Gonzalez C, Angulo MC. Functional myelin in cognition and neurodevelopmental disorders. Cell Mol Life Sci 2024; 81:181. [PMID: 38615095 PMCID: PMC11016012 DOI: 10.1007/s00018-024-05222-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 03/18/2024] [Accepted: 03/30/2024] [Indexed: 04/15/2024]
Abstract
In vertebrates, oligodendrocytes (OLs) are glial cells of the central nervous system (CNS) responsible for the formation of the myelin sheath that surrounds the axons of neurons. The myelin sheath plays a crucial role in the transmission of neuronal information by promoting the rapid saltatory conduction of action potentials and providing neurons with structural and metabolic support. Saltatory conduction, first described in the peripheral nervous system (PNS), is now generally recognized as a universal evolutionary innovation to respond quickly to the environment: myelin helps us think and act fast. Nevertheless, the role of myelin in the central nervous system, especially in the brain, may not be primarily focused on accelerating conduction speed but rather on ensuring precision. Its principal function could be to coordinate various neuronal networks, promoting their synchronization through oscillations (or rhythms) relevant for specific information processing tasks. Interestingly, myelin has been directly involved in different types of cognitive processes relying on brain oscillations, and myelin plasticity is currently considered to be part of the fundamental mechanisms for memory formation and maintenance. However, despite ample evidence showing the involvement of myelin in cognition and neurodevelopmental disorders characterized by cognitive impairments, the link between myelin, brain oscillations, cognition and disease is not yet fully understood. In this review, we aim to highlight what is known and what remains to be explored to understand the role of myelin in high order brain processes.
Collapse
Affiliation(s)
- Hasni Khelfaoui
- Université Paris Cité, Institute of Psychiatry and Neuroscience of Paris (IPNP), INSERM U1266, 75014, Paris, France
| | - Cristobal Ibaceta-Gonzalez
- Université Paris Cité, Institute of Psychiatry and Neuroscience of Paris (IPNP), INSERM U1266, 75014, Paris, France
| | - Maria Cecilia Angulo
- Université Paris Cité, Institute of Psychiatry and Neuroscience of Paris (IPNP), INSERM U1266, 75014, Paris, France.
- GHU-PARIS Psychiatrie Et Neurosciences, Hôpital Sainte Anne, 75014, Paris, France.
| |
Collapse
|
7
|
Looser ZJ, Faik Z, Ravotto L, Zanker HS, Jung RB, Werner HB, Ruhwedel T, Möbius W, Bergles DE, Barros LF, Nave KA, Weber B, Saab AS. Oligodendrocyte-axon metabolic coupling is mediated by extracellular K + and maintains axonal health. Nat Neurosci 2024; 27:433-448. [PMID: 38267524 PMCID: PMC10917689 DOI: 10.1038/s41593-023-01558-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 12/13/2023] [Indexed: 01/26/2024]
Abstract
The integrity of myelinated axons relies on homeostatic support from oligodendrocytes (OLs). To determine how OLs detect axonal spiking and how rapid axon-OL metabolic coupling is regulated in the white matter, we studied activity-dependent calcium (Ca2+) and metabolite fluxes in the mouse optic nerve. We show that fast axonal spiking triggers Ca2+ signaling and glycolysis in OLs. OLs detect axonal activity through increases in extracellular potassium (K+) concentrations and activation of Kir4.1 channels, thereby regulating metabolite supply to axons. Both pharmacological inhibition and OL-specific inactivation of Kir4.1 reduce the activity-induced axonal lactate surge. Mice lacking oligodendroglial Kir4.1 exhibit lower resting lactate levels and altered glucose metabolism in axons. These early deficits in axonal energy metabolism are associated with late-onset axonopathy. Our findings reveal that OLs detect fast axonal spiking through K+ signaling, making acute metabolic coupling possible and adjusting the axon-OL metabolic unit to promote axonal health.
Collapse
Affiliation(s)
- Zoe J Looser
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
- Neuroscience Center Zurich, University and ETH Zurich, Zurich, Switzerland
| | - Zainab Faik
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
- Neuroscience Center Zurich, University and ETH Zurich, Zurich, Switzerland
| | - Luca Ravotto
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
- Neuroscience Center Zurich, University and ETH Zurich, Zurich, Switzerland
| | - Henri S Zanker
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
- Neuroscience Center Zurich, University and ETH Zurich, Zurich, Switzerland
| | - Ramona B Jung
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Hauke B Werner
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Torben Ruhwedel
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Wiebke Möbius
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Dwight E Bergles
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD, USA
| | - L Felipe Barros
- Centro de Estudios Científicos (CECs), Valdivia, Chile
- Facultad de Medicina y Ciencia, Universidad San Sebastián, Valdivia, Chile
| | - Klaus-Armin Nave
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Bruno Weber
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
- Neuroscience Center Zurich, University and ETH Zurich, Zurich, Switzerland
| | - Aiman S Saab
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland.
- Neuroscience Center Zurich, University and ETH Zurich, Zurich, Switzerland.
| |
Collapse
|
8
|
Husseini L, Geladaris A, Weber MS. Toward identifying key mechanisms of progression in multiple sclerosis. Trends Neurosci 2024; 47:58-70. [PMID: 38102058 DOI: 10.1016/j.tins.2023.11.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 10/16/2023] [Accepted: 11/14/2023] [Indexed: 12/17/2023]
Abstract
A major therapeutic goal in the treatment of multiple sclerosis (MS) is to prevent the accumulation of disability over an often decades-long disease course. Disability progression can result from acute relapses as well as from CNS intrinsic parenchymal disintegration without de novo CNS lesion formation. Research focus has shifted to progression not associated with acute inflammation, as it is not sufficiently controlled by currently available treatments. This review outlines how recent advances in the understanding of the pathogenesis of progressive MS have been facilitated by the development of more precise, less static pathogenetic concepts of progressive MS, as well as by new techniques for the analysis of region-specific proteomic and transcriptomic signatures in the human CNS. We highlight key drivers of MS disease progression and potential targets in its treatment.
Collapse
Affiliation(s)
- Leila Husseini
- Department of Neurology, University Medical Center, Göttingen, Germany
| | - Anastasia Geladaris
- Institute of Neuropathology, University Medical Center, Göttingen, Germany; Fraunhofer Institute for Translational Medicine and Pharmacology, 37073 Göttingen, Germany
| | - Martin S Weber
- Department of Neurology, University Medical Center, Göttingen, Germany; Institute of Neuropathology, University Medical Center, Göttingen, Germany; Fraunhofer Institute for Translational Medicine and Pharmacology, 37073 Göttingen, Germany.
| |
Collapse
|
9
|
Nave KA, Asadollahi E, Sasmita A. Expanding the function of oligodendrocytes to brain energy metabolism. Curr Opin Neurobiol 2023; 83:102782. [PMID: 37703600 DOI: 10.1016/j.conb.2023.102782] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 08/15/2023] [Accepted: 08/16/2023] [Indexed: 09/15/2023]
Abstract
Oligodendrocytes are best known for wrapping myelin, a unique specialization that enables energy-efficient and fast axonal impulse propagation in white matter tracts and fibers of the cortical circuitry. However, myelinating oligodendrocytes have additional metabolic functions that are only gradually understood, including the regulated release of pyruvate/lactate and extracellular vesicles, both of which are in support of the axonal energy balance. The axon-supportive functions of glial cells are older than myelin in nervous system evolution and implicate oligodendrocyte dysfunction and loss of myelin integrity as a risk factor for progressive neurodegeneration in brain diseases.
Collapse
Affiliation(s)
- Klaus-Armin Nave
- Department of Neurogenetics, Max Planck Institute of Multidisciplinary Sciences, Göttingen.
| | - Ebrahim Asadollahi
- Department of Neurogenetics, Max Planck Institute of Multidisciplinary Sciences, Göttingen. https://twitter.com/EbrahimAsadoll3
| | - Andrew Sasmita
- Department of Neurogenetics, Max Planck Institute of Multidisciplinary Sciences, Göttingen. https://twitter.com/AOSasmita
| |
Collapse
|
10
|
Krämer-Albers EM, Werner HB. Mechanisms of axonal support by oligodendrocyte-derived extracellular vesicles. Nat Rev Neurosci 2023:10.1038/s41583-023-00711-y. [PMID: 37258632 DOI: 10.1038/s41583-023-00711-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/28/2023] [Indexed: 06/02/2023]
Abstract
Extracellular vesicles (EVs) have recently emerged as versatile elements of cell communication in the nervous system, mediating tissue homeostasis. EVs influence the physiology of their target cells via horizontal transfer of molecular cargo between cells and by triggering signalling pathways. In this Review, we discuss recent work revealing that EVs mediate interactions between oligodendrocytes and neurons, which are relevant for maintaining the structural integrity of axons. In response to neuronal activity, myelinating oligodendrocytes release EVs, which are internalized by neurons and provide axons with key factors that improve axonal transport, stress resistance and energy homeostasis. Glia-to-neuron transfer of EVs is thus a crucial facet of axonal preservation. When glial support is impaired, axonal integrity is progressively lost, as observed in myelin-related disorders, other neurodegenerative diseases and with normal ageing. We highlight the mechanisms that oligodendroglial EVs use to sustain axonal integrity and function.
Collapse
Affiliation(s)
- Eva-Maria Krämer-Albers
- Institute of Developmental Biology and Neurobiology, Johannes Gutenberg University Mainz, Mainz, Germany.
| | - Hauke B Werner
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| |
Collapse
|
11
|
Masson MA, Nait-Oumesmar B. Emerging concepts in oligodendrocyte and myelin formation, inputs from the zebrafish model. Glia 2023; 71:1147-1163. [PMID: 36645033 DOI: 10.1002/glia.24336] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 12/20/2022] [Accepted: 12/29/2022] [Indexed: 01/17/2023]
Abstract
Oligodendrocytes (OLs) are the myelinating cells of the central nervous system (CNS), which are derived from OL precursor cells. Myelin insulates axons allowing the saltatory conduction of action potentials and also provides trophic and metabolic supports to axons. Interestingly, oligodendroglial cells have the capacity to sense neuronal activity, which regulates myelin sheath formation via the vesicular release of neurotransmitters. Neuronal activity-dependent regulation of myelination is mediated by specialized interaction between axons and oligodendroglia, involving both synaptic and extra-synaptic modes of communications. The zebrafish has provided key advantages for the study of the myelination process in the CNS. External development and transparent larval stages of this vertebrate specie combined with the existence of several transgenic reporter lines provided key advances in oligodendroglial cell biology, axo-glial interactions and CNS myelination. In this publication, we reviewed and discussed the most recent knowledge on OL development and myelin formation, with a focus on mechanisms regulating these fundamental biological processes in the zebrafish. Especially, we highlighted the critical function of axons and oligodendroglia modes of communications and calcium signaling in myelin sheath formation and growth. Finally, we reviewed the relevance of these knowledge's in demyelinating diseases and drug discovery of pharmacological compounds favoring myelin regeneration.
Collapse
Affiliation(s)
- Mary-Amélie Masson
- Sorbonne Université, Institut du Cerveau, Paris Brain Institute - ICM, Inserm, CNRS, APHP, Hôpital de la Pitié-Salpêtrière, Paris, France
| | - Brahim Nait-Oumesmar
- Sorbonne Université, Institut du Cerveau, Paris Brain Institute - ICM, Inserm, CNRS, APHP, Hôpital de la Pitié-Salpêtrière, Paris, France
| |
Collapse
|
12
|
Perez-Gianmarco L, Kurt B, Kukley M. Technical approaches and challenges to study AMPA receptors in oligodendrocyte lineage cells: Past, present, and future. Glia 2023; 71:819-847. [PMID: 36453615 DOI: 10.1002/glia.24305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 11/05/2022] [Accepted: 11/10/2022] [Indexed: 12/03/2022]
Abstract
Receptors for α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPARs) are ligand-gated ionotropic receptors for glutamate that is a major excitatory neurotransmitter in the central nervous system. AMPARs are located at postsynaptic sites of neuronal synapses where they mediate fast synaptic signaling and synaptic plasticity. Remarkably, AMPARs are also expressed by glial cells. Their expression by the oligodendrocyte (OL) lineage cells is of special interest because AMPARs mediate fast synaptic communication between neurons and oligodendrocyte progenitor cells (OPCs), modulate proliferation and differentiation of OPCs, and may also be involved in regulation of myelination. On the other hand, during pathological conditions, AMPARs may mediate damage of the OL lineage cells. In the present review, we focus on the technical approaches that have been used to study AMPARs in the OL lineage cells, and discuss future perspectives of AMPAR research in these glial cells.
Collapse
Affiliation(s)
- Lucila Perez-Gianmarco
- Laboratory of Neuronal and Glial Physiology, Achucarro Basque Center for Neuroscience, Leioa, Spain.,Department of Neurosciences, University of the Basque Country (UPV/EHU), Leioa, Spain
| | - Begüm Kurt
- Laboratory of Neuronal and Glial Physiology, Achucarro Basque Center for Neuroscience, Leioa, Spain.,Department of Neurosciences, University of the Basque Country (UPV/EHU), Leioa, Spain
| | - Maria Kukley
- Laboratory of Neuronal and Glial Physiology, Achucarro Basque Center for Neuroscience, Leioa, Spain.,Ikerbasque - Basque Foundation for Science, Bilbao, Spain
| |
Collapse
|
13
|
Recent Insights into the Functional Role of AMPA Receptors in the Oligodendrocyte Lineage Cells In Vivo. Int J Mol Sci 2023; 24:ijms24044138. [PMID: 36835546 PMCID: PMC9967469 DOI: 10.3390/ijms24044138] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 02/13/2023] [Accepted: 02/14/2023] [Indexed: 02/22/2023] Open
Abstract
This review discusses the experimental findings of several recent studies which investigated the functional role of AMPA receptors (AMPARs) in oligodendrocyte lineage cells in vivo, in mice and in zebrafish. These studies provided valuable information showing that oligodendroglial AMPARs may be involved in the modulation of proliferation, differentiation, and migration of oligodendroglial progenitors, as well as survival of myelinating oligodendrocytes during physiological conditions in vivo. They also suggested that targeting the subunit composition of AMPARs may be an important strategy for treating diseases. However, at the same time, the experimental findings taken together still do not provide a clear picture on the topic. Hence, new ideas and new experimental designs are required for understanding the functional role of AMPARs in the oligodendrocyte lineage cells in vivo. It is also necessary to consider more closely the temporal and spatial aspects of AMPAR-mediated signalling in the oligodendrocyte lineage cells. These two important aspects are routinely discussed by neuronal physiologists studying glutamatergic synaptic transmission, but are rarely debated and thought about by researchers studying glial cells.
Collapse
|
14
|
Kwon J, Lee S, Jo Y, Choi M. All-optical observation on activity-dependent nanoscale dynamics of myelinated axons. NEUROPHOTONICS 2023; 10:015003. [PMID: 36699624 PMCID: PMC9868287 DOI: 10.1117/1.nph.10.1.015003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 01/05/2023] [Indexed: 06/17/2023]
Abstract
SIGNIFICANCE In the mammalian brain, rapid conduction of neural information is supported by the myelin, the functional efficacy of which shows steep dependence on its nanoscale cytoarchitecture. Although previous in vitro studies have suggested that neural activity accompanies nanometer-scale cellular deformations, whether neural activity can dynamically remodel the myelinated axon has remained unexplored due to the technical challenge in observing its nanostructural dynamics in living tissues. AIM We aim to observe activity-dependent nanostructural dynamics of myelinated axons in a living brain tissue. APPROACH We introduced a novel all-optical approach combining a nanoscale dynamic readout based on spectral interferometry and optogenetic control of neural excitation in an acute brain slice preparation. RESULTS In response to optogenetically evoked neuronal burst firing, the myelinated axons exhibited progressive and reversible spectral redshifts, corresponding to the transient swelling at a subnanometer scale. We further revealed that the activity-dependent nanostructural dynamics was localized to the paranode. CONCLUSIONS Our all-optical studies substantiate that myelinated axon exhibits activity-dependent nanoscale swelling, which potentially serves to dynamically tune the transmission speed of neural information.
Collapse
Affiliation(s)
- Junhwan Kwon
- Sungkyunkwan University, Department of Biomedical Engineering, Suwon, Republic of Korea
- Institute for Basic Science, Center for Neuroscience Imaging Research, Suwon, Republic of Korea
| | - Sungho Lee
- Seoul National University, School of Biological Sciences, Seoul, Republic of Korea
- Seoul National University, The Institute of Molecular Biology and Genetics, Seoul, Republic of Korea
| | - Yongjae Jo
- Institute for Basic Science, Center for Neuroscience Imaging Research, Suwon, Republic of Korea
| | - Myunghwan Choi
- Seoul National University, School of Biological Sciences, Seoul, Republic of Korea
- Seoul National University, The Institute of Molecular Biology and Genetics, Seoul, Republic of Korea
| |
Collapse
|
15
|
Acheta J, Bhatia U, Haley J, Hong J, Rich K, Close R, Bechler ME, Belin S, Poitelon Y. Piezo channels contribute to the regulation of myelination in Schwann cells. Glia 2022; 70:2276-2289. [PMID: 35903933 PMCID: PMC10638658 DOI: 10.1002/glia.24251] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 07/11/2022] [Accepted: 07/14/2022] [Indexed: 12/19/2022]
Abstract
Peripheral nerves and Schwann cells have to sustain constant mechanical constraints, caused by developmental growth as well as stretches associated with movements of the limbs and mechanical compressions from daily activities. In Schwann cells, signaling molecules sensitive to stiffness or stretch of the extracellular matrix, such as YAP/TAZ, have been shown to be critical for Schwann cell development and peripheral nerve regeneration. YAP/TAZ have also been suggested to contribute to tumorigenesis, neuropathic pain, and inherited disorders. Yet, the role of mechanosensitive ion channels in myelinating Schwann cells is vastly unexplored. Here we comprehensively assessed the expression of mechanosensitive ion channels in Schwann cells and identified that PIEZO1 and PIEZO2 are among the most abundant mechanosensitive ion channels expressed by Schwann cells. Using classic genetic ablation studies, we show that PIEZO1 is a transient inhibitor of radial and longitudinal myelination in Schwann cells. Contrastingly, we show that PIEZO2 may be required for myelin formation, as the absence of PIEZO2 in Schwann cells delays myelin formation. We found an epistatic relationship between PIEZO1 and PIEZO2, at both the morphological and molecular levels. Finally, we show that PIEZO1 channels affect the regulation of YAP/TAZ activation in Schwann cells. Overall, we present here the first demonstration that PIEZO1 and PIEZO2 contribute to mechanosensation in Schwann cells as well myelin development in the peripheral nervous system.
Collapse
Affiliation(s)
- Jenica Acheta
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, New York, USA
| | - Urja Bhatia
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, New York, USA
| | - Jeanette Haley
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, New York, USA
| | - Jiayue Hong
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, New York, USA
| | - Kyle Rich
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, New York, USA
| | - Rachel Close
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, New York, USA
| | - Marie E. Bechler
- Department of Cell and Developmental Biology, State University of New York Upstate Medical University, Syracuse, New York, USA
- Department of Neuroscience and Physiology, State University of New York Upstate Medical University, Syracuse, New York, USA
| | - Sophie Belin
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, New York, USA
| | - Yannick Poitelon
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, New York, USA
| |
Collapse
|
16
|
Lam M, Takeo K, Almeida RG, Cooper MH, Wu K, Iyer M, Kantarci H, Zuchero JB. CNS myelination requires VAMP2/3-mediated membrane expansion in oligodendrocytes. Nat Commun 2022; 13:5583. [PMID: 36151203 PMCID: PMC9508103 DOI: 10.1038/s41467-022-33200-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Accepted: 09/07/2022] [Indexed: 11/08/2022] Open
Abstract
Myelin is required for rapid nerve signaling and is emerging as a key driver of CNS plasticity and disease. How myelin is built and remodeled remains a fundamental question of neurobiology. Central to myelination is the ability of oligodendrocytes to add vast amounts of new cell membrane, expanding their surface areas by many thousand-fold. However, how oligodendrocytes add new membrane to build or remodel myelin is not fully understood. Here, we show that CNS myelin membrane addition requires exocytosis mediated by the vesicular SNARE proteins VAMP2/3. Genetic inactivation of VAMP2/3 in myelinating oligodendrocytes caused severe hypomyelination and premature death without overt loss of oligodendrocytes. Through live imaging, we discovered that VAMP2/3-mediated exocytosis drives membrane expansion within myelin sheaths to initiate wrapping and power sheath elongation. In conjunction with membrane expansion, mass spectrometry of oligodendrocyte surface proteins revealed that VAMP2/3 incorporates axon-myelin adhesion proteins that are collectively required to form nodes of Ranvier. Together, our results demonstrate that VAMP2/3-mediated membrane expansion in oligodendrocytes is indispensable for myelin formation, uncovering a cellular pathway that could sculpt myelination patterns in response to activity-dependent signals or be therapeutically targeted to promote regeneration in disease.
Collapse
Affiliation(s)
- Mable Lam
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Koji Takeo
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA
- Pharmaceutical Research Laboratories, Toray Industries, Inc., Kamakura, Kanagawa, Japan
| | - Rafael G Almeida
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Madeline H Cooper
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Kathryn Wu
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Manasi Iyer
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Husniye Kantarci
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA
| | - J Bradley Zuchero
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA.
| |
Collapse
|
17
|
Tsutsui S, Morgan M, Tedford H, You H, Zamponi GW, Stys PK. Copper ions, prion protein and Aβ modulate Ca levels in central nervous system myelin in an NMDA receptor-dependent manner. Mol Brain 2022; 15:67. [PMID: 35883145 PMCID: PMC9327403 DOI: 10.1186/s13041-022-00955-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2022] [Accepted: 07/12/2022] [Indexed: 11/10/2022] Open
Abstract
As in neurons, CNS myelin expresses N-Methyl-D-Aspartate Receptors (NMDARs) that subserve physiological roles, but have the potential to induce injury to this vital element. Using 2-photon imaging of myelinic Ca in live ex vivo mouse optic nerves, we show that Cu ions potently modulate Ca levels in an NMDAR-dependent manner. Chelating Cu in the perfusate induced a substantial increase in Ca levels, and also caused significant axo-myelinic injury. Myelinic NMDARs are shown to be regulated by cellular prion protein; only in prion protein KO optic nerves does application of NMDA + D-serine induce a large Ca increase, consistent with strong desensitization of these receptors in the presence of prion protein limiting Ca overload. Aβ1-42 peptide induced a large Ca increase that was also Cu-dependent, and was blocked by NMDAR antagonism. Our results indicate that like in neurons, myelinic NMDARs permeate potentially injurious amounts of Ca, and are also potently regulated by micromolar Cu and activated by Aβ1-42 peptides. These findings shed mechanistic light on the important primary white matter injury frequently observed in Alzheimer's brain.
Collapse
Affiliation(s)
- Shigeki Tsutsui
- Department of Clinical Neurosciences, University of Calgary, Calgary, AB, T2N 4N1, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Megan Morgan
- Department of Clinical Neurosciences, University of Calgary, Calgary, AB, T2N 4N1, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Hugo Tedford
- Department of Clinical Neurosciences, University of Calgary, Calgary, AB, T2N 4N1, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Haitao You
- Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, T2N 4N1, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Gerald W Zamponi
- Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, T2N 4N1, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Peter K Stys
- Department of Clinical Neurosciences, University of Calgary, Calgary, AB, T2N 4N1, Canada. .,Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada.
| |
Collapse
|
18
|
Paes-Colli Y, Aguiar AFL, Isaac AR, Ferreira BK, Campos RMP, Trindade PMP, de Melo Reis RA, Sampaio LS. Phytocannabinoids and Cannabis-Based Products as Alternative Pharmacotherapy in Neurodegenerative Diseases: From Hypothesis to Clinical Practice. Front Cell Neurosci 2022; 16:917164. [PMID: 35707521 PMCID: PMC9189313 DOI: 10.3389/fncel.2022.917164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2022] [Accepted: 05/10/2022] [Indexed: 11/19/2022] Open
Abstract
Historically, Cannabis is one of the first plants to be domesticated and used in medicine, though only in the last years the amount of Cannabis-based products or medicines has increased worldwide. Previous preclinical studies and few published clinical trials have demonstrated the efficacy and safety of Cannabis-based medicines in humans. Indeed, Cannabis-related medicines are used to treat multiple pathological conditions, including neurodegenerative disorders. In clinical practice, Cannabis products have already been introduced to treatment regimens of Alzheimer’s disease, Parkinson’s disease and Multiple Sclerosis’s patients, and the mechanisms of action behind the reported improvement in the clinical outcome and disease progression are associated with their anti-inflammatory, immunosuppressive, antioxidant, and neuroprotective properties, due to the modulation of the endocannabinoid system. In this review, we describe the role played by the endocannabinoid system in the physiopathology of Alzheimer, Parkinson, and Multiple Sclerosis, mainly at the neuroimmunological level. We also discuss the evidence for the correlation between phytocannabinoids and their therapeutic effects in these disorders, thus describing the main clinical studies carried out so far on the therapeutic performance of Cannabis-based medicines.
Collapse
Affiliation(s)
- Yolanda Paes-Colli
- Instituto de Biofísica Carlos Chagas Filho (IBCCF), Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Andrey F. L. Aguiar
- Instituto de Biofísica Carlos Chagas Filho (IBCCF), Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Alinny Rosendo Isaac
- Instituto de Bioquímica Médica Leopoldo De Meis (IBqM), Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Bruna K. Ferreira
- Instituto de Bioquímica Médica Leopoldo De Meis (IBqM), Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Raquel Maria P. Campos
- Instituto de Biofísica Carlos Chagas Filho (IBCCF), Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Priscila Martins Pinheiro Trindade
- Instituto de Biofísica Carlos Chagas Filho (IBCCF), Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Ricardo Augusto de Melo Reis
- Instituto de Biofísica Carlos Chagas Filho (IBCCF), Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Luzia S. Sampaio
- Instituto de Biofísica Carlos Chagas Filho (IBCCF), Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
- *Correspondence: Luzia S. Sampaio,
| |
Collapse
|
19
|
Thomason EJ, Suárez-Pozos E, Afshari FS, Rosenberg PA, Dupree JL, Fuss B. Deletion of the Sodium-Dependent Glutamate Transporter GLT-1 in Maturing Oligodendrocytes Attenuates Myelination of Callosal Axons During a Postnatal Phase of Central Nervous System Development. Front Cell Neurosci 2022; 16:905299. [PMID: 35722615 PMCID: PMC9203689 DOI: 10.3389/fncel.2022.905299] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Accepted: 05/16/2022] [Indexed: 11/13/2022] Open
Abstract
The sodium-dependent glutamate transporter GLT-1 (EAAT2, SLC1A2) has been well-described as an important regulator of extracellular glutamate homeostasis in the central nervous system (CNS), a function that is performed mainly through its presence on astrocytes. There is, however, increasing evidence for the expression of GLT-1 in CNS cells other than astrocytes and in functional roles that are mediated by mechanisms downstream of glutamate uptake. In this context, GLT-1 expression has been reported for both neurons and oligodendrocytes (OLGs), and neuronal presynaptic presence of GLT-1 has been implicated in the regulation of glutamate uptake, gene expression, and mitochondrial function. Much less is currently known about the functional roles of GLT-1 expressed by OLGs. The data presented here provide first evidence that GLT-1 expressed by maturing OLGs contributes to the modulation of developmental myelination in the CNS. More specifically, using inducible and conditional knockout mice in which GLT-1 was deleted in maturing OLGs during a peak period of myelination (between 2 and 4 weeks of age) revealed hypomyelinated characteristics in the corpus callosum of preferentially male mice. These characteristics included reduced percentages of smaller diameter myelinated axons and reduced myelin thickness. Interestingly, this myelination phenotype was not found to be associated with major changes in myelin gene expression. Taken together, the data presented here demonstrate that GLT-1 expressed by maturing OLGs is involved in the modulation of the morphological aspects associated with CNS myelination in at least the corpus callosum and during a developmental window that appears of particular vulnerability in males compared to females.
Collapse
Affiliation(s)
- Elizabeth J Thomason
- Department of Anatomy and Neurobiology, Virginia Commonwealth University School of Medicine, Richmond, VA, United States
| | - Edna Suárez-Pozos
- Department of Anatomy and Neurobiology, Virginia Commonwealth University School of Medicine, Richmond, VA, United States
| | - Fatemah S Afshari
- Department of Anatomy and Neurobiology, Virginia Commonwealth University School of Medicine, Richmond, VA, United States
| | - Paul A Rosenberg
- Department of Neurology and the F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, United States
| | - Jeffrey L Dupree
- Department of Anatomy and Neurobiology, Virginia Commonwealth University School of Medicine, Richmond, VA, United States
| | - Babette Fuss
- Department of Anatomy and Neurobiology, Virginia Commonwealth University School of Medicine, Richmond, VA, United States
| |
Collapse
|
20
|
Morgan ML, Teo W, Hernandez Y, Brideau C, Cummins K, Kuipers HF, Stys PK. Cuprizone-induced Demyelination in Mouse Brain is not due to Depletion of Copper. ASN Neuro 2022; 14:17590914221126367. [PMID: 36114624 PMCID: PMC9483969 DOI: 10.1177/17590914221126367] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
The cuprizone (CPZ) model allows the study of the biochemical processes underlying
nonautoimmune-mediated demyelination, remyelination, and chronic white matter disease
progression. CPZ is a copper (Cu) chelator that chiefly causes oligodendrocyte apoptosis
in the corpus callosum and cerebellum when administered in the mouse diet. While
disruption of Cu homeostasis is known to cause neurodegeneration (as is observed in
Wilson’s and Menkes disease), no consensus exists to date as to CPZ’s mechanism of action.
We sought to determine whether CPZ-induced pathology is due to Cu depletion as is
generally believed. Cu supplementation in chow, in stoichiometric excess to the added CPZ,
did not reduce CPZ-induced demyelination in C57Bl/6 mice. Moreover, equivalent doses of
other known Cu chelators neocuproine and D-penicillamine (D-Pen) failed to induce central
nervous system (CNS) demyelination. Since administration of D-Pen in the treatment of
Wilson’s disease can induce hypocupremia, we next sought to recreate penicillamine-induced
Cu deficiency to compare with purported CPZ-induced Cu deficiency. The resulting clinical
phenotype and histopathology were unlike that of CPZ. D-Pen-treated mice exhibited digit
paralysis, tail flaccidity, subcutaneous hemorrhaging, and optic and sciatic neuropathy,
all of which were prevented with Cu supplementation. No demyelination of the corpus
callosum or cerebellum was observed, even with D-Pen doses tenfold higher than CPZ.
Intriguingly, addition of D-Pen to the CPZ diet paradoxically prevented demyelination in a
dose-dependent manner.
Collapse
Affiliation(s)
- Megan L. Morgan
- Cumming School of Medicine, Department of Clinical Neurosciences, University of Calgary, Hotchkiss Brain Institute, Calgary, 3330 Hospital Drive N.W. HRIC 1B37A, Calgary, AB, T2N 4N1, Canada
| | - Wulin Teo
- Cumming School of Medicine, Department of Clinical Neurosciences, University of Calgary, Hotchkiss Brain Institute, Calgary, 3330 Hospital Drive N.W. HRIC 1B37A, Calgary, AB, T2N 4N1, Canada
| | - Yda Hernandez
- Cumming School of Medicine, Department of Clinical Neurosciences, University of Calgary, Hotchkiss Brain Institute, Calgary, 3330 Hospital Drive N.W. HRIC 1B37A, Calgary, AB, T2N 4N1, Canada
| | - Craig Brideau
- Cumming School of Medicine, Department of Clinical Neurosciences, University of Calgary, Hotchkiss Brain Institute, Calgary, 3330 Hospital Drive N.W. HRIC 1B37A, Calgary, AB, T2N 4N1, Canada
| | - Karen Cummins
- Cumming School of Medicine, Department of Clinical Neurosciences, University of Calgary, Hotchkiss Brain Institute, Calgary, 3330 Hospital Drive N.W. HRIC 1B37A, Calgary, AB, T2N 4N1, Canada
| | - Hedwich F. Kuipers
- Cumming School of Medicine, Department of Clinical Neurosciences, University of Calgary, Hotchkiss Brain Institute, Calgary, 3330 Hospital Drive N.W. HRIC 1B37A, Calgary, AB, T2N 4N1, Canada
| | - Peter K. Stys
- Cumming School of Medicine, Department of Clinical Neurosciences, University of Calgary, Hotchkiss Brain Institute, Calgary, 3330 Hospital Drive N.W. HRIC 1B37A, Calgary, AB, T2N 4N1, Canada
| |
Collapse
|
21
|
Loss of monocarboxylate transporter 1 aggravates white matter injury after experimental subarachnoid hemorrhage in rats. Front Med 2021; 15:887-902. [PMID: 34874512 DOI: 10.1007/s11684-021-0879-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 06/25/2021] [Indexed: 11/26/2022]
Abstract
Monocarboxylic acid transporter 1 (MCT1) maintains axonal function by transferring lactic acid from oligodendrocytes to axons. Subarachnoid hemorrhage (SAH) induces white matter injury, but the involvement of MCT1 is unclear. In this study, the SAH model of adult male Sprague-Dawley rats was used to explore the role of MCT1 in white matter injury after SAH. At 48 h after SAH, oligodendrocyte MCT1 was significantly reduced, and the exogenous overexpression of MCT1 significantly improved white matter integrity and long-term cognitive function. Motor training after SAH significantly increased the number of ITPR2+SOX10+ oligodendrocytes and upregulated the level of MCT1, which was positively correlated with the behavioral ability of rats. In addition, miR-29b and miR-124 levels were significantly increased in SAH rats compared with non-SAH rats. Further intervention experiments showed that miR-29b and miR-124 could negatively regulate the level of MCT1. This study confirmed that the loss of MCT1 may be one of the mechanisms of white matter damage after SAH and may be caused by the negative regulation of miR-29b and miR-124. MCT1 may be involved in the neurological improvement of rehabilitation training after SAH.
Collapse
|
22
|
Fairless R, Bading H, Diem R. Pathophysiological Ionotropic Glutamate Signalling in Neuroinflammatory Disease as a Therapeutic Target. Front Neurosci 2021; 15:741280. [PMID: 34744612 PMCID: PMC8567076 DOI: 10.3389/fnins.2021.741280] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 09/30/2021] [Indexed: 01/15/2023] Open
Abstract
Glutamate signalling is an essential aspect of neuronal communication involving many different glutamate receptors, and underlies the processes of memory, learning and synaptic plasticity. Despite neuroinflammatory diseases covering a range of maladies with very different biological causes and pathophysiologies, a central role for dysfunctional glutamate signalling is becoming apparent. This is not just restricted to the well-described role of glutamate in mediating neurodegeneration, but also includes a myriad of other influences that glutamate can exert on the vasculature, as well as immune cell and glial regulation, reflecting the ability of neurons to communicate with these compartments in order to couple their activity with neuronal requirements. Here, we discuss the role of pathophysiological glutamate signalling in neuroinflammatory disease, using both multiple sclerosis and Alzheimer's disease as examples, and how current steps are being made to harness our growing understanding of these processes in the development of neuroprotective strategies. This review focuses in particular on N-methyl-D-aspartate (NMDA) and 2-amino-3-(3-hydroxy-5-methylisooxazol-4-yl) propionate (AMPA) type ionotropic glutamate receptors, although metabotropic, G-protein-coupled glutamate receptors may also contribute to neuroinflammatory processes. Given the indispensable roles of glutamate-gated ion channels in synaptic communication, means of pharmacologically distinguishing between physiological and pathophysiological actions of glutamate will be discussed that allow deleterious signalling to be inhibited whilst minimising the disturbance of essential neuronal function.
Collapse
Affiliation(s)
- Richard Fairless
- Department of Neurology, University Clinic Heidelberg, Heidelberg, Germany.,Clinical Cooperation Unit (CCU) Neurooncology, German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Hilmar Bading
- Department of Neurobiology, Interdisciplinary Center for Neurosciences, Heidelberg University, Heidelberg, Germany
| | - Ricarda Diem
- Department of Neurology, University Clinic Heidelberg, Heidelberg, Germany.,Clinical Cooperation Unit (CCU) Neurooncology, German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg, Germany
| |
Collapse
|
23
|
Periods of synchronized myelin changes shape brain function and plasticity. Nat Neurosci 2021; 24:1508-1521. [PMID: 34711959 DOI: 10.1038/s41593-021-00917-2] [Citation(s) in RCA: 63] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 07/30/2021] [Indexed: 12/11/2022]
Abstract
Myelin, a lipid membrane that wraps axons, enabling fast neurotransmission and metabolic support to axons, is conventionally thought of as a static structure that is set early in development. However, recent evidence indicates that in the central nervous system (CNS), myelination is a protracted and plastic process, ongoing throughout adulthood. Importantly, myelin is emerging as a potential modulator of neuronal networks, and evidence from human studies has highlighted myelin as a major player in shaping human behavior and learning. Here we review how myelin changes throughout life and with learning. We discuss potential mechanisms of myelination at different life stages, explore whether myelin plasticity provides the regenerative potential of the CNS white matter, and question whether changes in myelin may underlie neurological disorders.
Collapse
|
24
|
Sun Q, Cao W, Luo J. The roles of GluN3-containing N-methyl-D-aspartate receptor in central nerve system. Zhejiang Da Xue Xue Bao Yi Xue Ban 2021; 50:651-658. [PMID: 34986531 DOI: 10.3724/zdxbyxb-2021-0167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The N-methyl-D-aspartate receptor (NMDAR) in central nerve system is mostly composed of GluN1 and GluN2 subunits. The classical NMDAR has been intensively studied. However, GluN3‑containing NMDAR is much less expressed and have atypical channel properties. Recently, accumulating evidences have revealed two types of GluN3‑containing NMDAR: glutamate-gated GluN1/GluN2/GluN3 NMDAR and glycine-gated GluN1/GluN3 NMDAR. The former may play important roles in regulating synapse maturation and pruning non-used synapses, and its elevated expression at the adult stage may alter synaptic reorganization in some neuropsychiatric disorders. The latter is expressed in the medial habenula and involves in control of aversion. This article reviews the recent progresses on the expression, functional properties of GluN3‑containing atypical NMDARs and the physiological and pathological relevance.
Collapse
Affiliation(s)
- Qi Sun
- School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou 310058, China
| | - Wei Cao
- School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou 310058, China
| | - Jianhong Luo
- School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou 310058, China
| |
Collapse
|
25
|
Bordeleau M, Fernández de Cossío L, Lacabanne C, Savage JC, Vernoux N, Chakravarty M, Tremblay MÈ. Maternal high-fat diet modifies myelin organization, microglial interactions, and results in social memory and sensorimotor gating deficits in adolescent mouse offspring. Brain Behav Immun Health 2021; 15:100281. [PMID: 34589781 PMCID: PMC8474164 DOI: 10.1016/j.bbih.2021.100281] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 06/04/2021] [Indexed: 12/29/2022] Open
Abstract
Prenatal exposure to maternal high-fat diet (mHFD) acts as a risk factor for various neurodevelopmental alterations in the progeny. Recent studies in mice revealed that mHFD results in both neuroinflammation and hypomyelination in the exposed offspring. Microglia, the brain-resident macrophages, play crucial roles during brain development, notably by modulating oligodendrocyte populations and performing phagocytosis of myelin sheaths. Previously, we reported that mHFD modifies microglial phenotype (i.e., morphology, interactions with their microenvironment, transcripts) in the hippocampus of male and female offspring. In the current study, we further explored whether mHFD may induce myelination changes among the hippocampal-corpus callosum-prefrontal cortex pathway, and result in behavioral outcomes in adolescent offspring of the two sexes. To this end, female mice were fed with control chow or HFD for 4 weeks before mating, during gestation, and until weaning of their litter. Histological and ultrastructural analyses revealed an increased density of myelin associated with a reduced area of cytosolic myelin channels in the corpus callosum of mHFD-exposed male compared to female offspring. Transcripts of myelination-associated genes including Igf1 -a growth factor released by microglia- were also lower, specifically in the hippocampus (without changes in the prefrontal cortex) of adolescent male mouse offspring. These changes in myelin were not related to an altered density, distribution, or maturation of oligodendrocytes, instead we found that microglia within the corpus callosum of mHFD-exposed offspring showed reduced numbers of mature lysosomes and increased synaptic contacts, suggesting microglial implication in the modified myelination. At the behavioral level, both male and female mHFD-exposed adolescent offspring presented loss of social memory and sensorimotor gating deficits. These results together highlight the importance of studying oligodendrocyte-microglia crosstalk and its involvement in the long-term brain alterations that result from prenatal mHFD in offspring across sexes.
Collapse
Affiliation(s)
- Maude Bordeleau
- Integrated Program in Neuroscience, McGill University, Montréal, QC, Canada.,Axe Neurosciences, Centre de Recherche du CHU de Québec - Université Laval, Québec, QC, Canada
| | | | - Chloé Lacabanne
- Integrated Program in Neuroscience, McGill University, Montréal, QC, Canada
| | - Julie C Savage
- Axe Neurosciences, Centre de Recherche du CHU de Québec - Université Laval, Québec, QC, Canada
| | - Nathalie Vernoux
- Axe Neurosciences, Centre de Recherche du CHU de Québec - Université Laval, Québec, QC, Canada
| | - Mallar Chakravarty
- Integrated Program in Neuroscience, McGill University, Montréal, QC, Canada.,Cerebral Imaging Center, Douglas Mental Health University Institute, McGill University, Montréal, QC, Canada.,Department of Psychiatry, McGill University, Montréal, QC, Canada.,Department of Biological and Biomedical Engineering, McGill University, Montréal, QC, Canada
| | - Marie-Ève Tremblay
- Axe Neurosciences, Centre de Recherche du CHU de Québec - Université Laval, Québec, QC, Canada.,Département de Médecine Moléculaire, Université Laval, Québec, QC, Canada.,Department of Neurology and Neurosurgery, McGill University, Montréal, QC, Canada.,Division of Medical Sciences, University of Victoria, Victoria, BC, Canada.,Department of Biochemistry and Molecular Biology, Faculty of Medicine, The University of British Colombia, Vancouver, BC, Canada
| |
Collapse
|
26
|
Turan F, Yilmaz Ö, Schünemann L, Lindenberg TT, Kalanithy JC, Harder A, Ahmadi S, Duman T, MacDonald RB, Winter D, Liu C, Odermatt B. Effect of modulating glutamate signaling on myelinating oligodendrocytes and their development-A study in the zebrafish model. J Neurosci Res 2021; 99:2774-2792. [PMID: 34520578 DOI: 10.1002/jnr.24940] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Revised: 07/12/2021] [Accepted: 07/21/2021] [Indexed: 01/02/2023]
Abstract
Myelination is crucial for the development and maintenance of axonal integrity, especially fast axonal action potential conduction. There is increasing evidence that glutamate signaling and release through neuronal activity modulates the myelination process. In this study, we examine the effect of manipulating glutamate signaling on myelination of oligodendrocyte (OL) lineage cells and their development in zebrafish (zf). We use the "intensity-based glutamate-sensing fluorescent reporter" (iGluSnFR) in the zf model (both sexes) to address the hypothesis that glutamate is implicated in regulation of myelinating OLs. Our results show that glial iGluSnFR expression significantly reduces OL lineage cell number and the expression of myelin markers in larvae (zfl) and adult brains. The specific glutamate receptor agonist, L-AP4, rescues this iGluSnFR effect by significantly increasing the expression of the myelin-related genes, plp1b and mbpa, and enhances myelination in L-AP4-injected zfl compared to controls. Furthermore, we demonstrate that degrading glutamate using Glutamat-Pyruvate Transaminase (GPT) or the blockade of glutamate reuptake by L-trans-pyrrolidine-2,4-dicarboxylate (PDC) significantly decreases myelin-related genes and drastically declines myelination in brain ventricle-injected zfl. Moreover, we found that myelin-specific ClaudinK (CldnK) and 36K protein expression is significantly decreased in iGluSnFR-expressing zfl and adult brains compared to controls. Taken together, this study confirms that glutamate signaling is directly required for the preservation of myelinating OLs and for the myelination process itself. These findings further suggest that glutamate signaling may provide novel targets to therapeutically boost remyelination in several demyelinating diseases of the CNS.
Collapse
Affiliation(s)
- Funda Turan
- Medical Faculty, Institute of Neuroanatomy, University of Bonn, Bonn, Germany.,Faculty of Science, Biology Department, Ankara University, Ankara, Turkey
| | - Öznur Yilmaz
- Medical Faculty, Institute of Anatomy and Cell-Biology, University of Bonn, Bonn, Germany
| | - Lena Schünemann
- Medical Faculty, Institute of Anatomy and Cell-Biology, University of Bonn, Bonn, Germany
| | - Tobias T Lindenberg
- Medical Faculty, Institute of Neuroanatomy, University of Bonn, Bonn, Germany
| | - Jeshurun C Kalanithy
- Medical Faculty, Institute of Anatomy and Cell-Biology, University of Bonn, Bonn, Germany
| | - Alexander Harder
- Institute of Physical and Theoretical Chemistry, University of Bonn, Bonn, Germany
| | - Shiva Ahmadi
- Medical Faculty, Institute for Biochemistry and Molecular Biology (IBMB), University of Bonn, Bonn, Germany
| | - Türker Duman
- Faculty of Science, Biology Department, Ankara University, Ankara, Turkey
| | - Ryan B MacDonald
- Institute of Ophthalmology, University College London, London, UK
| | - Dominic Winter
- Medical Faculty, Institute for Biochemistry and Molecular Biology (IBMB), University of Bonn, Bonn, Germany
| | - Changsheng Liu
- Medical Faculty, Institute of Anatomy and Cell-Biology, University of Bonn, Bonn, Germany
| | - Benjamin Odermatt
- Medical Faculty, Institute of Neuroanatomy, University of Bonn, Bonn, Germany.,Medical Faculty, Institute of Anatomy and Cell-Biology, University of Bonn, Bonn, Germany
| |
Collapse
|
27
|
Almeida RG, Williamson JM, Madden ME, Early JJ, Voas MG, Talbot WS, Bianco IH, Lyons DA. Myelination induces axonal hotspots of synaptic vesicle fusion that promote sheath growth. Curr Biol 2021; 31:3743-3754.e5. [PMID: 34270947 PMCID: PMC8445327 DOI: 10.1016/j.cub.2021.06.036] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 05/17/2021] [Accepted: 06/11/2021] [Indexed: 02/08/2023]
Abstract
Myelination of axons by oligodendrocytes enables fast saltatory conduction. Oligodendrocytes are responsive to neuronal activity, which has been shown to induce changes to myelin sheaths, potentially to optimize conduction and neural circuit function. However, the cellular bases of activity-regulated myelination in vivo are unclear, partly due to the difficulty of analyzing individual myelinated axons over time. Activity-regulated myelination occurs in specific neuronal subtypes and can be mediated by synaptic vesicle fusion, but several questions remain: it is unclear whether vesicular fusion occurs stochastically along axons or in discrete hotspots during myelination and whether vesicular fusion regulates myelin targeting, formation, and/or growth. It is also unclear why some neurons, but not others, exhibit activity-regulated myelination. Here, we imaged synaptic vesicle fusion in individual neurons in living zebrafish and documented robust vesicular fusion along axons during myelination. Surprisingly, we found that axonal vesicular fusion increased upon and required myelination. We found that axonal vesicular fusion was enriched in hotspots, namely the heminodal non-myelinated domains into which sheaths grew. Blocking vesicular fusion reduced the stable formation and growth of myelin sheaths, and chemogenetically stimulating neuronal activity promoted sheath growth. Finally, we observed high levels of axonal vesicular fusion only in neuronal subtypes that exhibit activity-regulated myelination. Our results identify a novel "feedforward" mechanism whereby the process of myelination promotes the neuronal activity-regulated signal, vesicular fusion that, in turn, consolidates sheath growth along specific axons selected for myelination.
Collapse
Affiliation(s)
- Rafael G Almeida
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK.
| | - Jill M Williamson
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Megan E Madden
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Jason J Early
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Matthew G Voas
- Department of Developmental Biology, Stanford University, Stanford, CA, USA; National Cancer Institute, Frederick, MD, USA
| | - William S Talbot
- Department of Developmental Biology, Stanford University, Stanford, CA, USA
| | - Isaac H Bianco
- Department of Neuroscience, Physiology and Pharmacology, UCL, London, UK
| | - David A Lyons
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK.
| |
Collapse
|
28
|
Rupnik M, Baker D, Selwood DL. Oligodendrocytes, BK channels and remyelination. F1000Res 2021; 10:781. [PMID: 34909188 PMCID: PMC8596180 DOI: 10.12688/f1000research.53422.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/28/2021] [Indexed: 11/09/2023] Open
Abstract
Oligodendrocytes wrap multiple lamellae of their membrane, myelin, around axons of the central nervous system (CNS), to improve impulse conduction. Myelin synthesis is specialised and dynamic, responsive to local neuronal excitation. Subtle pathological insults are sufficient to cause significant neuronal metabolic impairment, so myelin preservation is necessary to safeguard neural networks. Multiple sclerosis (MS) is the most prevalent demyelinating disease of the CNS. In MS, inflammatory attacks against myelin, proposed to be autoimmune, cause myelin decay and oligodendrocyte loss, leaving neurons vulnerable. Current therapies target the prominent neuroinflammation but are mostly ineffective in protecting from neurodegeneration and the progressive neurological disability. People with MS have substantially higher levels of extracellular glutamate, the main excitatory neurotransmitter. This impairs cellular homeostasis to cause excitotoxic stress. Large conductance Ca2 +-activated K + channels (BK channels) could preserve myelin or allow its recovery by protecting cells from the resulting excessive excitability. This review evaluates the role of excitotoxic stress, myelination and BK channels in MS pathology, and explores the hypothesis that BK channel activation could be a therapeutic strategy to protect oligodendrocytes from excitotoxic stress in MS. This could reduce progression of neurological disability if used in parallel to immunomodulatory therapies.
Collapse
Affiliation(s)
- Maddalena Rupnik
- Wolfson Insitute for Biomedical Research, University College London, London, WC1E 6BT, UK
| | - David Baker
- Centre for Neuroscience and Trauma, Blizard Institute, Queen Mary University of London, London, WC1E 6BT, UK
| | - David L. Selwood
- Wolfson Insitute for Biomedical Research, University College London, London, WC1E 6BT, UK
| |
Collapse
|
29
|
Rupnik M, Baker D, Selwood DL. Oligodendrocytes, BK channels and the preservation of myelin. F1000Res 2021; 10:781. [PMID: 34909188 PMCID: PMC8596180 DOI: 10.12688/f1000research.53422.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/02/2021] [Indexed: 11/20/2022] Open
Abstract
Oligodendrocytes wrap multiple lamellae of their membrane, myelin, around axons of the central nervous system (CNS), to improve impulse conduction. Myelin synthesis is specialised and dynamic, responsive to local neuronal excitation. Subtle pathological insults are sufficient to cause significant neuronal metabolic impairment, so myelin preservation is necessary to safeguard neural networks. Multiple sclerosis (MS) is the most prevalent demyelinating disease of the CNS. In MS, inflammatory attacks against myelin, proposed to be autoimmune, cause myelin decay and oligodendrocyte loss, leaving neurons vulnerable. Current therapies target the prominent neuroinflammation but are mostly ineffective in protecting from neurodegeneration and the progressive neurological disability. People with MS have substantially higher levels of extracellular glutamate, the main excitatory neurotransmitter. This impairs cellular homeostasis to cause excitotoxic stress. Large conductance Ca2 +-activated K + channels (BK channels) could preserve myelin or allow its recovery by protecting cells from the resulting excessive excitability. This review evaluates the role of excitotoxic stress, myelination and BK channels in MS pathology, and explores the hypothesis that BK channel activation could be a therapeutic strategy to protect oligodendrocytes from excitotoxic stress in MS. This could reduce progression of neurological disability if used in parallel to immunomodulatory therapies.
Collapse
Affiliation(s)
- Maddalena Rupnik
- Wolfson Insitute for Biomedical Research, University College London, London, WC1E 6BT, UK
| | - David Baker
- Centre for Neuroscience and Trauma, Blizard Institute, Queen Mary University of London, London, WC1E 6BT, UK
| | - David L. Selwood
- Wolfson Insitute for Biomedical Research, University College London, London, WC1E 6BT, UK
| |
Collapse
|
30
|
Ion Channels as New Attractive Targets to Improve Re-Myelination Processes in the Brain. Int J Mol Sci 2021; 22:ijms22147277. [PMID: 34298893 PMCID: PMC8305962 DOI: 10.3390/ijms22147277] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 06/28/2021] [Accepted: 07/01/2021] [Indexed: 12/20/2022] Open
Abstract
Multiple sclerosis (MS) is the most demyelinating disease of the central nervous system (CNS) characterized by neuroinflammation. Oligodendrocyte progenitor cells (OPCs) are cycling cells in the developing and adult CNS that, under demyelinating conditions, migrate to the site of lesions and differentiate into mature oligodendrocytes to remyelinate damaged axons. However, this process fails during disease chronicization due to impaired OPC differentiation. Moreover, OPCs are crucial players in neuro-glial communication as they receive synaptic inputs from neurons and express ion channels and neurotransmitter/neuromodulator receptors that control their maturation. Ion channels are recognized as attractive therapeutic targets, and indeed ligand-gated and voltage-gated channels can both be found among the top five pharmaceutical target groups of FDA-approved agents. Their modulation ameliorates some of the symptoms of MS and improves the outcome of related animal models. However, the exact mechanism of action of ion-channel targeting compounds is often still unclear due to the wide expression of these channels on neurons, glia, and infiltrating immune cells. The present review summarizes recent findings in the field to get further insights into physio-pathophysiological processes and possible therapeutic mechanisms of drug actions.
Collapse
|
31
|
Boscia F, Elkjaer ML, Illes Z, Kukley M. Altered Expression of Ion Channels in White Matter Lesions of Progressive Multiple Sclerosis: What Do We Know About Their Function? Front Cell Neurosci 2021; 15:685703. [PMID: 34276310 PMCID: PMC8282214 DOI: 10.3389/fncel.2021.685703] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Accepted: 05/23/2021] [Indexed: 12/19/2022] Open
Abstract
Despite significant advances in our understanding of the pathophysiology of multiple sclerosis (MS), knowledge about contribution of individual ion channels to axonal impairment and remyelination failure in progressive MS remains incomplete. Ion channel families play a fundamental role in maintaining white matter (WM) integrity and in regulating WM activities in axons, interstitial neurons, glia, and vascular cells. Recently, transcriptomic studies have considerably increased insight into the gene expression changes that occur in diverse WM lesions and the gene expression fingerprint of specific WM cells associated with secondary progressive MS. Here, we review the ion channel genes encoding K+, Ca2+, Na+, and Cl- channels; ryanodine receptors; TRP channels; and others that are significantly and uniquely dysregulated in active, chronic active, inactive, remyelinating WM lesions, and normal-appearing WM of secondary progressive MS brain, based on recently published bulk and single-nuclei RNA-sequencing datasets. We discuss the current state of knowledge about the corresponding ion channels and their implication in the MS brain or in experimental models of MS. This comprehensive review suggests that the intense upregulation of voltage-gated Na+ channel genes in WM lesions with ongoing tissue damage may reflect the imbalance of Na+ homeostasis that is observed in progressive MS brain, while the upregulation of a large number of voltage-gated K+ channel genes may be linked to a protective response to limit neuronal excitability. In addition, the altered chloride homeostasis, revealed by the significant downregulation of voltage-gated Cl- channels in MS lesions, may contribute to an altered inhibitory neurotransmission and increased excitability.
Collapse
Affiliation(s)
- Francesca Boscia
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, University of Naples "Federico II", Naples, Italy
| | - Maria Louise Elkjaer
- Neurology Research Unit, Department of Clinical Research, University of Southern Denmark, Odense, Denmark.,Department of Neurobiology Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - Zsolt Illes
- Neurology Research Unit, Department of Clinical Research, University of Southern Denmark, Odense, Denmark.,Department of Neurobiology Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark.,Department of Neurology, Odense University Hospital, Odense, Denmark
| | - Maria Kukley
- Achucarro Basque Center for Neuroscience, Leioa, Spain.,Ikerbasque Basque Foundation for Science, Bilbao, Spain
| |
Collapse
|
32
|
Pease-Raissi SE, Chan JR. Building a (w)rapport between neurons and oligodendroglia: Reciprocal interactions underlying adaptive myelination. Neuron 2021; 109:1258-1273. [PMID: 33621477 PMCID: PMC8068592 DOI: 10.1016/j.neuron.2021.02.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 01/12/2021] [Accepted: 01/29/2021] [Indexed: 12/27/2022]
Abstract
Myelin, multilayered lipid-rich membrane extensions formed by oligodendrocytes around neuronal axons, is essential for fast and efficient action potential propagation in the central nervous system. Initially thought to be a static and immutable process, myelination is now appreciated to be a dynamic process capable of responding to and modulating neuronal function throughout life. While the importance of this type of plasticity, called adaptive myelination, is now well accepted, we are only beginning to understand the underlying cellular and molecular mechanisms by which neurons communicate experience-driven circuit activation to oligodendroglia and precisely how changes in oligodendrocytes and their myelin refine neuronal function. Here, we review recent findings addressing this reciprocal relationship in which neurons alter oligodendroglial form and oligodendrocytes conversely modulate neuronal function.
Collapse
Affiliation(s)
- Sarah E Pease-Raissi
- Weill Institute for Neuroscience, Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA.
| | - Jonah R Chan
- Weill Institute for Neuroscience, Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA.
| |
Collapse
|
33
|
Simkins TJ, Duncan GJ, Bourdette D. Chronic Demyelination and Axonal Degeneration in Multiple Sclerosis: Pathogenesis and Therapeutic Implications. Curr Neurol Neurosci Rep 2021; 21:26. [PMID: 33835275 DOI: 10.1007/s11910-021-01110-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/24/2021] [Indexed: 02/07/2023]
Abstract
PURPOSE OF REVIEW Multiple sclerosis (MS) is the most common demyelinating disease of the central nervous system (CNS). Inflammatory attacks in MS lead to both demyelination and axonal damage. However, due to incomplete remyelination most MS lesions remain chronically demyelinated. In parallel, there is axonal degeneration in the CNS of MS patients, contributing to progressive disability. There are currently no approved therapies that adequately restore myelin or protect axons from degeneration. In this review, we will discuss the pathophysiology of axonal loss and chronic demyelination in MS and how understanding this pathophysiology is leading to the development of new MS therapeutics. RECENT FINDINGS Ongoing research into the function of oligodendrocytes and myelin has revealed the importance of their relationship with neuronal health. Demyelination in MS leads to a number of pathophysiologic changes contributing to axonal generation. Among these are mitochondrial dysfunction, persistent neuroinflammation, and the effects of reactive oxygen and nitrogen species. With this information, we review currently approved and investigational therapies designed to restore lost or damaged myelin and protect against neuronal degeneration. The development of therapies to restore lost myelin and protect neurons is a promising avenue of investigation for the benefit of patients with MS.
Collapse
Affiliation(s)
- Tyrell J Simkins
- Department of Neurology, Oregon Health and Science University, 3181S W Sam Jackson Rd L226, Portland, OR, 97239, USA. .,Jungers Center for Neurosciences Research, Oregon Health and Science University, Portland, OR, USA. .,Department of Neurology, Portland VA Medical Center, Portland, OR, USA.
| | - Greg J Duncan
- Department of Neurology, Oregon Health and Science University, 3181S W Sam Jackson Rd L226, Portland, OR, 97239, USA.,Jungers Center for Neurosciences Research, Oregon Health and Science University, Portland, OR, USA
| | - Dennis Bourdette
- Department of Neurology, Oregon Health and Science University, 3181S W Sam Jackson Rd L226, Portland, OR, 97239, USA.,Jungers Center for Neurosciences Research, Oregon Health and Science University, Portland, OR, USA
| |
Collapse
|
34
|
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.
Collapse
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
| |
Collapse
|
35
|
Su X, Vasilkovska T, Fröhlich N, Garaschuk O. Characterization of cell type-specific S100B expression in the mouse olfactory bulb. Cell Calcium 2021; 94:102334. [PMID: 33460952 DOI: 10.1016/j.ceca.2020.102334] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 12/11/2020] [Accepted: 12/11/2020] [Indexed: 12/17/2022]
Abstract
S100B is an EF-hand type Ca2+-binding protein of the S100 family, known to support neurogenesis and to promote the interactions between brain's nervous and immune systems. Here, we characterized the expression of S100B in the mouse olfactory bulb, a neurogenic niche comprising mature and adult-born neurons, astrocytes, oligodendrocytes and microglia. Besides astrocytes, for which S100B is a classical marker, S100B was also expressed in NG2 cells and, surprisingly, in APC-positive myelinating oligodendrocytes but not in mature/adult-born neurons or microglia. Various layers of the bulb differed substantially in the composition of S100B-positive cells, with the highest fraction of the APC-positive oligodendrocytes found in the granule cell layer. Across all layers, ∼50 % of NG2 cells were S100B-negative. Finally, our data revealed a strong correlation between the fraction of myelinating oligodendrocytes among the S100B-positive cells and the oligodendrocyte density in different brain areas, underscoring the importance of S100B for the establishment and maintenance of myelin sheaths.
Collapse
Affiliation(s)
- Xin Su
- Institute of Physiology, Department of Neurophysiology, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Tamara Vasilkovska
- Institute of Physiology, Department of Neurophysiology, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Nicole Fröhlich
- Institute of Physiology, Department of Neurophysiology, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Olga Garaschuk
- Institute of Physiology, Department of Neurophysiology, Eberhard Karls University of Tübingen, Tübingen, Germany.
| |
Collapse
|
36
|
Bergaglio T, Luchicchi A, Schenk GJ. Engine Failure in Axo-Myelinic Signaling: A Potential Key Player in the Pathogenesis of Multiple Sclerosis. Front Cell Neurosci 2021; 15:610295. [PMID: 33642995 PMCID: PMC7902503 DOI: 10.3389/fncel.2021.610295] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 01/20/2021] [Indexed: 12/12/2022] Open
Abstract
Multiple Sclerosis (MS) is a complex and chronic disease of the central nervous system (CNS), characterized by both degenerative and inflammatory processes leading to axonal damage, demyelination, and neuronal loss. In the last decade, the traditional outside-in standpoint on MS pathogenesis, which identifies a primary autoimmune inflammatory etiology, has been challenged by a complementary inside-out theory. By focusing on the degenerative processes of MS, the axo-myelinic system may reveal new insights into the disease triggering mechanisms. Oxidative stress (OS) has been widely described as one of the means driving tissue injury in neurodegenerative disorders, including MS. Axonal mitochondria constitute the main energy source for electrically active axons and neurons and are largely vulnerable to oxidative injury. Consequently, axonal mitochondrial dysfunction might impair efficient axo-glial communication, which could, in turn, affect axonal integrity and the maintenance of axonal, neuronal, and synaptic signaling. In this review article, we argue that OS-derived mitochondrial impairment may underline the dysfunctional relationship between axons and their supportive glia cells, specifically oligodendrocytes and that this mechanism is implicated in the development of a primary cytodegeneration and a secondary pro-inflammatory response (inside-out), which in turn, together with a variably primed host's immune system, may lead to the onset of MS and its different subtypes.
Collapse
Affiliation(s)
| | | | - Geert J. Schenk
- Department of Anatomy and Neurosciences, Amsterdam Neuroscience, Amsterdam University Medical Center, Amsterdam MS Center, Amsterdam, Netherlands
| |
Collapse
|
37
|
Tong J, Zhou Y, Huang J, Zhang P, Fan F, Chen S, Tian B, Cui Y, Tian L, Tan S, Wang Z, Feng W, Yang F, Hare S, Goldwaser EL, Bruce HA, Kvarta M, Chen S, Kochunov P, Tan Y, Hong LE. N-methyl-D-aspartate Receptor Antibody and White Matter Deficits in Schizophrenia Treatment-Resistance. Schizophr Bull 2021; 47:1463-1472. [PMID: 33515249 PMCID: PMC8379535 DOI: 10.1093/schbul/sbab003] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Insufficient or lack of response to antipsychotic medications in some patients with schizophrenia is a major challenge in psychiatry, but the underlying mechanisms remain unclear. Two seemingly unrelated observations, cerebral white matter and N-methyl-D-aspartate receptor (NMDAR) hypofunction, have been linked to treatment-resistant schizophrenia (TRS). As NMDARs are critical to axonal myelination and signal transduction, we hypothesized that NMDAR antibody (Ab), when present in schizophrenia, may impair NMDAR functions and white matter microstructures, contributing to TRS. In this study, 50 patients with TRS, 45 patients with nontreatment-resistant schizophrenia (NTRS), 53 patients with schizophrenia at treatment initiation schizophrenia (TIS), and 90 healthy controls were enrolled. Serum NMDAR Ab levels and white matter diffusion tensor imaging fractional anisotropy (FA) were assessed. The white matter specificity effects by NMDAR Ab were assessed by comparing with effects on cortical and subcortical gray matter. Serum NMDAR Ab levels of the TRS were significantly higher than those of the NTRS (P = .035). In patients with TRS, higher NMDAR Ab levels were significantly associated with reduced whole-brain average FA (r = -.37; P = .026), with the strongest effect at the genu of corpus callosum (r = -.50; P = .0021, significant after correction for multiple comparisons). Conversely, there was no significant correlation between whole-brain or regional cortical thickness or any subcortical gray matter structural volume and NMDAR Ab levels in TRS. Our finding highlights a potential NMDAR mechanism on white matter microstructure impairment in schizophrenia that may contribute to their treatment resistance to antipsychotic medications.
Collapse
Affiliation(s)
- Jinghui Tong
- Peking University HuiLongGuan Clinical Medical School, Beijing Huilongguan Hospital, Beijing, P. R. China
| | - Yanfang Zhou
- Peking University HuiLongGuan Clinical Medical School, Beijing Huilongguan Hospital, Beijing, P. R. China
| | - Junchao Huang
- Peking University HuiLongGuan Clinical Medical School, Beijing Huilongguan Hospital, Beijing, P. R. China
| | - Ping Zhang
- Peking University HuiLongGuan Clinical Medical School, Beijing Huilongguan Hospital, Beijing, P. R. China
| | - Fengmei Fan
- Peking University HuiLongGuan Clinical Medical School, Beijing Huilongguan Hospital, Beijing, P. R. China
| | - Song Chen
- Peking University HuiLongGuan Clinical Medical School, Beijing Huilongguan Hospital, Beijing, P. R. China
| | - Baopeng Tian
- Peking University HuiLongGuan Clinical Medical School, Beijing Huilongguan Hospital, Beijing, P. R. China
| | - Yimin Cui
- Department of Pharmacy, Peking University First Hospital, Beijing, P. R. China
| | - Li Tian
- Institute of Biomedicine and Translational Medicine, Department of Physiology, Faculty of Medicine, University of Tartu, Tartu, Estonia
| | - Shuping Tan
- Peking University HuiLongGuan Clinical Medical School, Beijing Huilongguan Hospital, Beijing, P. R. China
| | - Zhiren Wang
- Peking University HuiLongGuan Clinical Medical School, Beijing Huilongguan Hospital, Beijing, P. R. China
| | - Wei Feng
- Peking University HuiLongGuan Clinical Medical School, Beijing Huilongguan Hospital, Beijing, P. R. China
| | - Fude Yang
- Peking University HuiLongGuan Clinical Medical School, Beijing Huilongguan Hospital, Beijing, P. R. China
| | - Stephanie Hare
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Eric L Goldwaser
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Heather A Bruce
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Mark Kvarta
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Shuo Chen
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Peter Kochunov
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Yunlong Tan
- Peking University HuiLongGuan Clinical Medical School, Beijing Huilongguan Hospital, Beijing, P. R. China,To whom correspondence should be addressed; tel: +86-(10)-83024319, fax: +86-(10)-62710156, e-mail:
| | - L Elliot Hong
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA
| |
Collapse
|
38
|
Gallego-Delgado P, James R, Browne E, Meng J, Umashankar S, Tan L, Picon C, Mazarakis ND, Faisal AA, Howell OW, Reynolds R. Neuroinflammation in the normal-appearing white matter (NAWM) of the multiple sclerosis brain causes abnormalities at the nodes of Ranvier. PLoS Biol 2020; 18:e3001008. [PMID: 33315860 PMCID: PMC7769608 DOI: 10.1371/journal.pbio.3001008] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 12/28/2020] [Accepted: 11/20/2020] [Indexed: 01/02/2023] Open
Abstract
Changes to the structure of nodes of Ranvier in the normal-appearing white matter (NAWM) of multiple sclerosis (MS) brains are associated with chronic inflammation. We show that the paranodal domains in MS NAWM are longer on average than control, with Kv1.2 channels dislocated into the paranode. These pathological features are reproduced in a model of chronic meningeal inflammation generated by the injection of lentiviral vectors for the lymphotoxin-α (LTα) and interferon-γ (IFNγ) genes. We show that tumour necrosis factor (TNF), IFNγ, and glutamate can provoke paranodal elongation in cerebellar slice cultures, which could be reversed by an N-methyl-D-aspartate (NMDA) receptor blocker. When these changes were inserted into a computational model to simulate axonal conduction, a rapid decrease in velocity was observed, reaching conduction failure in small diameter axons. We suggest that glial cells activated by pro-inflammatory cytokines can produce high levels of glutamate, which triggers paranodal pathology, contributing to axonal damage and conduction deficits. Current thinking on the mechanisms by which multiple sclerosis gives rise to cumulative neurological disability revolves largely around focal lesions of inflammation and demyelination. However, some of the debilitating symptoms, such as severe fatigue, might be better explained by a more diffuse pathology. This study shows that paranodes in the white matter become abnormal as a result of neuroinflammation, which may be the result of the action of cytokines that cause glia to release glutamate.
Collapse
Affiliation(s)
- Patricia Gallego-Delgado
- Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Rachel James
- Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Eleanor Browne
- Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Joanna Meng
- Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Swetha Umashankar
- Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Li Tan
- Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Carmen Picon
- Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Nicholas D. Mazarakis
- Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - A. Aldo Faisal
- Department of Bioengineering, Faculty of Engineering, Imperial College London, London, United Kingdom
- Department of Computing, Faculty of Engineering, Imperial College London, London, United Kingdom
- Data Science Institute, Imperial College London, London, United Kingdom
| | - Owain W. Howell
- Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
- Institute of Life Sciences, Swansea University Medical School, Swansea University, Swansea, Wales
| | - Richard Reynolds
- Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
- Centre for Molecular Neuropathology, Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
- * E-mail:
| |
Collapse
|
39
|
Koller EJ, Chakrabarty P. Tau-Mediated Dysregulation of Neuroplasticity and Glial Plasticity. Front Mol Neurosci 2020; 13:151. [PMID: 32973446 PMCID: PMC7472665 DOI: 10.3389/fnmol.2020.00151] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 07/20/2020] [Indexed: 01/14/2023] Open
Abstract
The inability of individual neurons to compensate for aging-related damage leads to a gradual loss of functional plasticity in the brain accompanied by progressive impairment in learning and memory. Whereas this loss in neuroplasticity is gradual during normal aging, in neurodegenerative diseases such as Alzheimer’s disease (AD), this loss is accelerated dramatically, leading to the incapacitation of patients within a decade of onset of cognitive symptoms. The mechanisms that underlie this accelerated loss of neuroplasticity in AD are still not completely understood. While the progressively increasing proteinopathy burden, such as amyloid β (Aβ) plaques and tau tangles, definitely contribute directly to a neuron’s functional demise, the role of non-neuronal cells in controlling neuroplasticity is slowly being recognized as another major factor. These non-neuronal cells include astrocytes, microglia, and oligodendrocytes, which through regulating brain homeostasis, structural stability, and trophic support, play a key role in maintaining normal functioning and resilience of the neuronal network. It is believed that chronic signaling from these cells affects the homeostatic network of neuronal and non-neuronal cells to an extent to destabilize this harmonious milieu in neurodegenerative diseases like AD. Here, we will examine the experimental evidence regarding the direct and indirect pathways through which astrocytes and microglia can alter brain plasticity in AD, specifically as they relate to the development and progression of tauopathy. In this review article, we describe the concepts of neuroplasticity and glial plasticity in healthy aging, delineate possible mechanisms underlying tau-induced plasticity dysfunction, and discuss current clinical trials as well as future disease-modifying approaches.
Collapse
Affiliation(s)
- Emily J Koller
- Department of Neuroscience, University of Florida, Gainesville, FL, United States.,Center for Translational Research in Neurodegenerative Disease, University of Florida, Gainesville, FL, United States
| | - Paramita Chakrabarty
- Department of Neuroscience, University of Florida, Gainesville, FL, United States.,Center for Translational Research in Neurodegenerative Disease, University of Florida, Gainesville, FL, United States.,McKnight Brain Institute, University of Florida, Gainesville, FL, United States
| |
Collapse
|
40
|
Ganesh A, Luengo-Fernandez R, Rothwell PM. Late functional improvement and 5-year poststroke outcomes: a population-based cohort study. J Neurol Neurosurg Psychiatry 2020; 91:831-839. [PMID: 32576613 PMCID: PMC7402458 DOI: 10.1136/jnnp-2019-322365] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 03/24/2020] [Accepted: 05/27/2020] [Indexed: 11/06/2022]
Abstract
BACKGROUND Late functional improvement between 3 and 12 months poststroke occurs in about one in four patients with ischaemic stroke, more commonly in lacunar strokes. It is unknown whether this late improvement is associated with better long-term clinical or health economic outcomes. METHODS In a prospective, population-based cohort of 1-year ischaemic stroke survivors (Oxford Vascular Study; 2002-2014), we examined changes in functional status (modified Rankin Scale (mRS), Rivermead Mobility Index (RMI), Barthel Index (BI)) from 3 to 12 months poststroke. We used Cox regressions adjusted for age, sex, 3-month disability and stroke subtype (lacunar vs non-lacunar) to examine the association of late improvement (by ≥1 mRS grades, ≥1 RMI points and/or ≥2 BI points between 3 and 12 months) with 5-year mortality and institutionalisation. We used similarly adjusted generalised linear models to examine association with 5-year healthcare/social-care costs. RESULTS Among 1288 one-year survivors, 1135 (88.1%) had 3-month mRS >0, of whom 319 (28.1%) demonstrated late functional improvement between 3 and 12 months poststroke. Late improvers had lower 5-year mortality (aHR per mRS=0.68, 95% CI 0.51 to 0.91, p=0.009), institutionalisation (aHR 0.48, 0.33 to 0.72, p<0.001) and healthcare/social care costs (margin US$17 524, -24 763 to -10 284, p<0.001). These associations remained on excluding patients with recurrent strokes during follow-up (eg, 5-year mortality/institutionalisation: aHR 0.59, 0.44 to 0.79, p<0.001) and on examining late improvement per RMI and/or BI (eg, 5-year mortality/institutionalisation with RMI/BI: aHR 0.73, 0.58 to 0.92, p=0.008). CONCLUSION Late functional improvement poststroke is associated with lower 5-year mortality, institutionalisation rates and healthcare/social care costs. These findings should motivate patients and clinicians to maximise late recovery in routine practice, and to consider extending access to proven rehabilitative therapies during the first year poststroke.
Collapse
Affiliation(s)
- Aravind Ganesh
- Wolfson Centre for Prevention of Stroke and Dementia, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK.,Department of Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada
| | - Ramon Luengo-Fernandez
- Wolfson Centre for Prevention of Stroke and Dementia, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Peter Malcolm Rothwell
- Wolfson Centre for Prevention of Stroke and Dementia, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| |
Collapse
|
41
|
Marshall-Phelps KL, Kegel L, Baraban M, Ruhwedel T, Almeida RG, Rubio-Brotons M, Klingseisen A, Benito-Kwiecinski SK, Early JJ, Bin JM, Suminaite D, Livesey MR, Möbius W, Poole RJ, Lyons DA. Neuronal activity disrupts myelinated axon integrity in the absence of NKCC1b. J Cell Biol 2020; 219:e201909022. [PMID: 32364583 PMCID: PMC7337504 DOI: 10.1083/jcb.201909022] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 03/09/2020] [Accepted: 04/07/2020] [Indexed: 02/07/2023] Open
Abstract
Through a genetic screen in zebrafish, we identified a mutant with disruption to myelin in both the CNS and PNS caused by a mutation in a previously uncharacterized gene, slc12a2b, predicted to encode a Na+, K+, and Cl- (NKCC) cotransporter, NKCC1b. slc12a2b/NKCC1b mutants exhibited a severe and progressive pathology in the PNS, characterized by dysmyelination and swelling of the periaxonal space at the axon-myelin interface. Cell-type-specific loss of slc12a2b/NKCC1b in either neurons or myelinating Schwann cells recapitulated these pathologies. Given that NKCC1 is critical for ion homeostasis, we asked whether the disruption to myelinated axons in slc12a2b/NKCC1b mutants is affected by neuronal activity. Strikingly, we found that blocking neuronal activity completely prevented and could even rescue the pathology in slc12a2b/NKCC1b mutants. Together, our data indicate that NKCC1b is required to maintain neuronal activity-related solute homeostasis at the axon-myelin interface, and the integrity of myelinated axons.
Collapse
Affiliation(s)
| | - Linde Kegel
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Marion Baraban
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Torben Ruhwedel
- Electron Microscopy Core Unit, Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Rafael G. Almeida
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | | | - Anna Klingseisen
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | | | - Jason J. Early
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Jenea M. Bin
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Daumante Suminaite
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Matthew R. Livesey
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Wiebke Möbius
- Electron Microscopy Core Unit, Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Richard J. Poole
- Department of Cell and Developmental Biology, University College London, London, UK
| | - David A. Lyons
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| |
Collapse
|
42
|
Association between human gray matter metabotropic glutamate receptor-5 availability in vivo and white matter properties: a [ 11C]ABP688 PET and diffusion tensor imaging study. Brain Struct Funct 2020; 225:1805-1816. [PMID: 32495131 DOI: 10.1007/s00429-020-02094-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Accepted: 05/26/2020] [Indexed: 10/24/2022]
Abstract
Excitatory corticofugal projections in the subcortical white matter (WM) convey signals arising from local neuronal activity in the gray matter (GM). We hypothesized that metabotropic glutamate receptor-5 (mGluR5) availability in GM, as a surrogate marker for local glutamatergic neuronal activity, correlates with WM properties in healthy brain. We examined the relationship in healthy individuals between GM mGluR5 availability measured in vivo using [11C]ABP688 positron emission tomography (PET) and WM properties measured as fractional anisotropy (FA) using diffusion tensor imaging (DTI). Twenty-three healthy volunteers underwent this multimodal imaging. We calculated mGluR5 availability, [11C]ABP688 binding potential (BPND), using the simplified reference tissue model, and generated DTI FA maps using FMRIB's Diffusion Toolbox (FDT) along with Tract-Based Spatial Statistics (TBSS). To investigate the relationship between mGluR5 availability and FA, we performed voxel-wise and region of interest (ROI)-based analyses. The voxel-wise analysis showed significant positive correlations between the whole cerebral GM [11C]ABP688 BPND and the FA in widespread WM regions including the corpus callosum body, internal capsule, and corona radiata (FWE corrected p < 0.05). The ROI-based analysis also revealed significant positive correlations (Bonferroni-corrected threshold p < 0.00021) between [11C]ABP688 BPND in the frontal and parietal cortical GM and FA in the internal capsule (anterior limb and retrolenticular part). Using a novel multimodal imaging interrogation, we provide the first evidence that GM mGluR5 availability is significantly positively associated with WM properties in healthy subjects. Future comparison studies could determine whether this relationship is perturbed in neuropsychiatric disorders with dysregulated mGluR5 signaling.
Collapse
|
43
|
High-Frequency Microdomain Ca 2+ Transients and Waves during Early Myelin Internode Remodeling. Cell Rep 2020; 26:182-191.e5. [PMID: 30605675 PMCID: PMC6316190 DOI: 10.1016/j.celrep.2018.12.039] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 11/09/2018] [Accepted: 12/07/2018] [Indexed: 11/25/2022] Open
Abstract
Ensheathment of axons by myelin is a highly complex and multi-cellular process. Cytosolic calcium (Ca2+) changes in the myelin sheath have been implicated in myelin synthesis, but the source of this Ca2+ and the role of neuronal activity is not well understood. Using one-photon Ca2+ imaging, we investigated myelin sheath formation in the mouse somatosensory cortex and found a high rate of spontaneous microdomain Ca2+ transients and large-amplitude Ca2+ waves propagating along the internode. The frequency of Ca2+ transients and waves rapidly declines with maturation and reactivates during remyelination. Unexpectedly, myelin microdomain Ca2+ transients occur independent of neuronal action potential generation or network activity but are nearly completely abolished when the mitochondrial permeability transition pores are blocked. These findings are supported by the discovery of mitochondria organelles in non-compacted myelin. Together, the results suggest that myelin microdomain Ca2+ signals are cell-autonomously driven by high activity of mitochondria during myelin remodeling. Developing myelin sheaths show high rates of calcium transients and calcium waves Myelin calcium transients are independent from neuronal activity Adaxonal and paranodal myelin contained mitochondria Calcium transients require opening of mitochondrial permeability transition pores
Collapse
|
44
|
Neuron-oligodendroglia interactions: Activity-dependent regulation of cellular signaling. Neurosci Lett 2020; 727:134916. [PMID: 32194135 DOI: 10.1016/j.neulet.2020.134916] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 03/11/2020] [Accepted: 03/15/2020] [Indexed: 12/31/2022]
Abstract
Oligodendrocyte lineage cells (oligodendroglia) and neurons engage in bidirectional communication throughout life to support healthy brain function. Recent work shows that changes in neuronal activity can modulate proliferation, differentiation, and myelination to support the formation and function of neural circuits. While oligodendroglia express a diverse collection of receptors for growth factors, signaling molecules, neurotransmitters and neuromodulators, our knowledge of the intracellular signaling pathways that are regulated by neuronal activity remains largely incomplete. Many of the pathways that modulate oligodendroglia behavior are driven by changes in intracellular calcium signaling, which may differentially affect cytoskeletal dynamics, gene expression, maturation, integration, and axonal support. Additionally, activity-dependent neuron-oligodendroglia communication plays an integral role in the recovery from demyelinating injuries. In this review, we summarize the modalities of communication between neurons and oligodendroglia and explore possible roles of activity-dependent calcium signaling in mediating cellular behavior and myelination.
Collapse
|
45
|
Suárez-Pozos E, Thomason EJ, Fuss B. Glutamate Transporters: Expression and Function in Oligodendrocytes. Neurochem Res 2020; 45:551-560. [PMID: 30628017 PMCID: PMC6616022 DOI: 10.1007/s11064-018-02708-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 12/19/2018] [Accepted: 12/22/2018] [Indexed: 12/14/2022]
Abstract
Glutamate, the main excitatory neurotransmitter of the vertebrate central nervous system (CNS), is well known as a regulator of neuronal plasticity and neurodevelopment. Such glutamate function is thought to be mediated primarily by signaling through glutamate receptors. Thus, it requires a tight regulation of extracellular glutamate levels and a fine-tuned homeostasis that, when dysregulated, has been associated with a wide range of central pathologies including neuropsychiatric, neurodevelopmental, and neurodegenerative disorders. In the mammalian CNS, extracellular glutamate levels are controlled by a family of sodium-dependent glutamate transporters belonging to the solute carrier family 1 (SLC1) that are also referred to as excitatory amino acid transporters (EAATs). The presumed main function of EAATs has been best described in the context of synaptic transmission where EAATs expressed by astrocytes and neurons effectively regulate extracellular glutamate levels so that synapses can function independently. There is, however, increasing evidence that EAATs are expressed by cells other than astrocytes and neurons, and that they exhibit functions beyond glutamate clearance. In this review, we will focus on the expression and functions of EAATs in the myelinating cells of the CNS, oligodendrocytes. More specifically, we will discuss potential roles of oligodendrocyte-expressed EAATs in contributing to extracellular glutamate homeostasis, and in regulating oligodendrocyte maturation and CNS myelination by exerting signaling functions that have traditionally been associated with glutamate receptors. In addition, we will provide some examples for how dysregulation of oligodendrocyte-expressed EAATs may be involved in the pathophysiology of neurologic diseases.
Collapse
Affiliation(s)
- Edna Suárez-Pozos
- Department of Anatomy and Neurobiology, Virginia Commonwealth University School of Medicine, Box 980709, Richmond, VA, 23298, USA
| | - Elizabeth J Thomason
- Department of Anatomy and Neurobiology, Virginia Commonwealth University School of Medicine, Box 980709, Richmond, VA, 23298, USA
| | - Babette Fuss
- Department of Anatomy and Neurobiology, Virginia Commonwealth University School of Medicine, Box 980709, Richmond, VA, 23298, USA.
| |
Collapse
|
46
|
Abstract
Cells of the oligodendrocyte lineage express a wide range of Ca2+ channels and receptors that regulate oligodendrocyte progenitor cell (OPC) and oligodendrocyte formation and function. Here we define those key channels and receptors that regulate Ca2+ signaling and OPC development and myelination. We then discuss how the regulation of intracellular Ca2+ in turn affects OPC and oligodendrocyte biology in the healthy nervous system and under pathological conditions. Activation of Ca2+ channels and receptors in OPCs and oligodendrocytes by neurotransmitters converges on regulating intracellular Ca2+, making Ca2+ signaling a central candidate mediator of activity-driven myelination. Indeed, recent evidence indicates that localized changes in Ca2+ in oligodendrocytes can regulate the formation and remodeling of myelin sheaths and perhaps additional functions of oligodendrocytes and OPCs. Thus, decoding how OPCs and myelinating oligodendrocytes integrate and process Ca2+ signals will be important to fully understand central nervous system formation, health, and function.
Collapse
Affiliation(s)
- Pablo M Paez
- Department of Pharmacology and Toxicology and Hunter James Kelly Research Institute, Jacobs School of Medicine and Biomedical Sciences, The State University of New York, University at Buffalo, Buffalo, New York 14203, USA;
| | - David A Lyons
- Centre for Discovery Brain Sciences, Centre for Multiple Sclerosis Research, and Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, Edinburgh EH16 4SB, United Kingdom;
| |
Collapse
|
47
|
Tian N, Hanson KA, Canty AJ, Vickers JC, King AE. Microtubule‐dependent processes precede pathological calcium influx in excitotoxin‐induced axon degeneration. J Neurochem 2019; 152:542-555. [DOI: 10.1111/jnc.14909] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 10/02/2019] [Accepted: 10/31/2019] [Indexed: 12/12/2022]
Affiliation(s)
- Nan Tian
- Wicking Dementia Research and Education Centre University of Tasmania Hobart Tasmania Australia
| | - Kelsey A. Hanson
- Wicking Dementia Research and Education Centre University of Tasmania Hobart Tasmania Australia
| | - Alison J. Canty
- Wicking Dementia Research and Education Centre University of Tasmania Hobart Tasmania Australia
| | - James C. Vickers
- Wicking Dementia Research and Education Centre University of Tasmania Hobart Tasmania Australia
| | - Anna E. King
- Wicking Dementia Research and Education Centre University of Tasmania Hobart Tasmania Australia
| |
Collapse
|
48
|
Heterogeneity of Astrocytes in Grey and White Matter. Neurochem Res 2019; 46:3-14. [PMID: 31797158 DOI: 10.1007/s11064-019-02926-x] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 11/21/2019] [Accepted: 11/28/2019] [Indexed: 02/07/2023]
Abstract
Astrocytes are a diverse and heterogeneous type of glial cells. The major task of grey and white matter areas in the brain are computation of information at neuronal synapses and propagation of action potentials along axons, respectively, resulting in diverse demands for astrocytes. Adapting their function to the requirements in the local environment, astrocytes differ in morphology, gene expression, metabolism, and many other properties. Here we review the differential properties of protoplasmic astrocytes of grey matter and fibrous astrocytes located in white matter in respect to glutamate and energy metabolism, to their function at the blood-brain interface and to coupling via gap junctions. Finally, we discuss how this astrocytic heterogeneity might contribute to the different susceptibility of grey and white matter to ischemic insults.
Collapse
|
49
|
Calcium Signaling in Neurons and Glial Cells: Role of Cav1 channels. Neuroscience 2019; 421:95-111. [DOI: 10.1016/j.neuroscience.2019.09.041] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 09/27/2019] [Accepted: 09/30/2019] [Indexed: 11/18/2022]
|
50
|
Hughes AN, Appel B. Oligodendrocytes express synaptic proteins that modulate myelin sheath formation. Nat Commun 2019; 10:4125. [PMID: 31511515 PMCID: PMC6739339 DOI: 10.1038/s41467-019-12059-y] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 08/14/2019] [Indexed: 02/03/2023] Open
Abstract
Vesicular release from neurons promotes myelin sheath growth on axons. Oligodendrocytes express proteins that allow dendrites to respond to vesicular release at synapses, suggesting that axon-myelin contacts use similar communication mechanisms as synapses to form myelin sheaths. To test this, we used fusion proteins to track synaptic vesicle localization and membrane fusion in zebrafish during developmental myelination and investigated expression and localization of PSD95, a dendritic post-synaptic protein, within oligodendrocytes. Synaptic vesicles accumulate and exocytose at ensheathment sites with variable patterning and most sheaths localize PSD95 with patterning similar to exocytosis site location. Disruption of candidate PDZ-binding transsynaptic adhesion proteins in oligodendrocytes cause variable effects on sheath length and number. One candidate, Cadm1b, localizes to myelin sheaths where both PDZ binding and extracellular adhesion to axons mediate sheath growth. Our work raises the possibility that axon-glial communication contributes to myelin plasticity, providing new targets for mechanistic unraveling of developmental myelination.
Collapse
Affiliation(s)
- Alexandria N Hughes
- University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - Bruce Appel
- University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, CO, 80045, USA.
| |
Collapse
|