151
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OUP accepted manuscript. Brain 2022; 145:3179-3186. [DOI: 10.1093/brain/awac107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 01/25/2022] [Accepted: 03/13/2022] [Indexed: 11/15/2022] Open
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152
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Age-related changes in multiple sclerosis and experimental autoimmune encephalomyelitis. Semin Immunol 2022; 59:101631. [PMID: 35752572 DOI: 10.1016/j.smim.2022.101631] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 06/03/2022] [Accepted: 06/13/2022] [Indexed: 01/15/2023]
Abstract
A better understanding of the pathological mechanisms that drive neurodegeneration in people living with multiple sclerosis (MS) is needed to design effective therapies to treat and/or prevent disease progression. We propose that CNS-intrinsic inflammation and re-modelling of the sub-arachnoid space of the leptomeninges sets the stage for neurodegeneration from the earliest stages of MS. While neurodegenerative processes are clinically silent early in disease, ageing results in neurodegenerative changes that become clinically manifest as progressive disability. Here we review pathological correlates of MS disease progression, highlight emerging mouse models that mimic key progressive changes in MS, and provide new perspectives on therapeutic approaches to protect against MS-associated neurodegeneration.
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153
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Möck EEA, Honkonen E, Airas L. Synaptic Loss in Multiple Sclerosis: A Systematic Review of Human Post-mortem Studies. Front Neurol 2021; 12:782599. [PMID: 34912290 PMCID: PMC8666414 DOI: 10.3389/fneur.2021.782599] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 10/26/2021] [Indexed: 11/13/2022] Open
Abstract
Background: Gray matter pathology plays a central role in the progression of multiple sclerosis (MS). The occurrence of synaptic loss appears to be important but, to date, still poorly investigated aspect of MS pathology. In this systematic review, we drew from the recent knowledge about synaptic loss in human post-mortem studies. Methods: We conducted a systematic search with PubMed to identify relevant publications. Publications available from15 June 2021 were taken into account. We selected human post-mortem studies that quantitatively assessed the synapse number in MS tissue. Results: We identified 14 relevant publications out of which 9 reported synaptic loss in at least one investigated subregion. The most commonly used synaptic marker was synaptophysin; non-etheless, we found substantial differences in the methodology and the selection of reference tissue. Investigated regions included the cortex, the hippocampus, the cerebellum, the thalamus, and the spinal cord. Conclusion: Synaptic loss seems to take place throughout the entire central nervous system. However, the results are inconsistent, probably due to differences in the methodology. Moreover, synaptic loss appears to be a dynamic process, and thus the nature of this pathology might be captured using in vivo synaptic density measurements.
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Affiliation(s)
- E E Amelie Möck
- Division of Clinical Neurosciences, Turku University Hospital and University of Turku, Turku, Finland.,Turku PET Centre, Turku University Hospital and University of Turku, Turku, Finland
| | - Eveliina Honkonen
- Division of Clinical Neurosciences, Turku University Hospital and University of Turku, Turku, Finland.,Turku PET Centre, Turku University Hospital and University of Turku, Turku, Finland
| | - Laura Airas
- Division of Clinical Neurosciences, Turku University Hospital and University of Turku, Turku, Finland.,Turku PET Centre, Turku University Hospital and University of Turku, Turku, Finland
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154
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Havton LA, Biscola NP, Stern E, Mihaylov PV, Kubal CA, Wo JM, Gupta A, Baronowsky E, Ward MP, Jaffey DM, Powley TL. Human organ donor-derived vagus nerve biopsies allow for well-preserved ultrastructure and high-resolution mapping of myelinated and unmyelinated fibers. Sci Rep 2021; 11:23831. [PMID: 34903749 PMCID: PMC8668909 DOI: 10.1038/s41598-021-03248-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 11/15/2021] [Indexed: 11/09/2022] Open
Abstract
The vagus nerve provides motor, sensory, and autonomic innervation of multiple organs, and electrical vagus nerve stimulation (VNS) provides an adjunctive treatment option for e.g. medication-refractory epilepsy and treatment-resistant depression. The mechanisms of action for VNS are not known, and high-resolution anatomical mapping of the human vagus nerve is needed to better understand its functional organization. Electron microscopy (EM) is required for the detection of both myelinated and unmyelinated axons, but access to well-preserved human vagus nerves for ultrastructural studies is sparse. Intact human vagus nerve samples were procured intra-operatively from deceased organ donors, and tissues were immediately immersion fixed and processed for EM. Ultrastructural studies of cervical and sub-diaphragmatic vagus nerve segments showed excellent preservation of the lamellated wall of myelin sheaths, and the axolemma of myelinated and unmyelinated fibers were intact. Microtubules, neurofilaments, and mitochondria were readily identified in the axoplasm, and the ultrastructural integrity of Schwann cell nuclei, Remak bundles, and basal lamina was also well preserved. Digital segmentation of myelinated and unmyelinated axons allowed for determination of fiber size and myelination. We propose a novel source of human vagus nerve tissues for detailed ultrastructural studies and mapping to support efforts to refine neuromodulation strategies, including VNS.
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Affiliation(s)
- Leif A Havton
- Departments of Neurology and Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.
- James J. Peters Department of Veterans Affairs Medical Center, Bronx, NY, USA.
| | - Natalia P Biscola
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Esther Stern
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Plamen V Mihaylov
- Department of Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
| | | | - John M Wo
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Anita Gupta
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Elizabeth Baronowsky
- Department of Psychological Sciences, Purdue University, West Lafayette, IN, USA
| | - Matthew P Ward
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA
| | - Deborah M Jaffey
- Department of Psychological Sciences, Purdue University, West Lafayette, IN, USA
| | - Terry L Powley
- Department of Psychological Sciences, Purdue University, West Lafayette, IN, USA
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155
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Complement as a powerful "influencer" in the brain during development, adulthood and neurological disorders. Adv Immunol 2021; 152:157-222. [PMID: 34844709 DOI: 10.1016/bs.ai.2021.09.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The complement system was long considered as only a powerful effector arm of the immune system that, while critically protective, could lead to inflammation and cell death if overactivated, even in the central nervous system (CNS). However, in the past decade it has been recognized as playing critical roles in key physiological processes in the CNS, including neurogenesis and synaptic remodeling in the developing and adult brain. Inherent in these processes are the interactions with cells in the brain, and the cascade of interactions and functional consequences that ensue. As a result, investigations of therapeutic approaches for both suppressing excessive complement driven neurotoxicity and aberrant sculpting of neuronal circuits, require broad (and deep) knowledge of the functional activities of multiple components of this highly evolved and regulated system to avoid unintended negative consequences in the clinic. Advances in basic science are beginning to provide a roadmap for translation to therapeutics, with both small molecule and biologics. Here, we present examples of the critical roles of proper complement function in the development and sculpting of the nervous system, and in enabling rapid protection from infection and clearance of dying cells. Microglia are highlighted as important command centers that integrate signals from the complement system and other innate sensors that are programed to provide support and protection, but that direct detrimental responses to aberrant activation and/or regulation of the system. Finally, we present promising research areas that may lead to effective and precision strategies for complement targeted interventions to promote neurological health.
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156
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A lymphocyte-glia connection sets the pace for smoldering inflammation. Cell 2021; 184:5696-5698. [PMID: 34767775 DOI: 10.1016/j.cell.2021.10.018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 10/14/2021] [Accepted: 10/15/2021] [Indexed: 11/22/2022]
Abstract
Successful therapeutic options directly targeting disability progression in patients with multiple sclerosis (MS), a chronic inflammatory disorder of the central nervous system, are lacking. Now, a study published in Nature by Absinta and colleagues profiles a lymphocyte-glia connection at the edge of chronic active lesions that continuously drives neurodegenerative pathways.
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157
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Complement component 3 from astrocytes mediates retinal ganglion cell loss during neuroinflammation. Acta Neuropathol 2021; 142:899-915. [PMID: 34487221 DOI: 10.1007/s00401-021-02366-4] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2021] [Revised: 08/13/2021] [Accepted: 08/27/2021] [Indexed: 12/14/2022]
Abstract
Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system (CNS) characterized by varying degrees of secondary neurodegeneration. Retinal ganglion cells (RGC) are lost in MS in association with optic neuritis but the mechanisms of neuronal injury remain unclear. Complement component C3 has been implicated in retinal and cerebral synaptic pathology that may precede neurodegeneration. Herein, we examined post-mortem MS retinas, and then used a mouse model, experimental autoimmune encephalomyelitis (EAE), to examine the role of C3 in the pathogenesis of RGC loss associated with optic neuritis. First, we show extensive C3 expression in astrocytes (C3+/GFAP+ cells) and significant RGC loss (RBPMS+ cells) in post-mortem retinas from people with MS compared to retinas from non-MS individuals. A patient with progressive MS with a remote history of optic neuritis showed marked reactive astrogliosis with C3 expression in the inner retina extending into deeper layers in the affected eye more than the unaffected eye. To study whether C3 mediates retinal degeneration, we utilized global C3-/- EAE mice and found that they had less RGC loss and partially preserved neurites in the retina compared with C3+/+ EAE mice. C3-/- EAE mice had fewer axonal swellings in the optic nerve, reflecting reduced axonal injury, but had no changes in demyelination or T cell infiltration into the CNS. Using a C3-tdTomato reporter mouse line, we show definitive evidence of C3 expression in astrocytes in the retina and optic nerves of EAE mice. Conditional deletion of C3 in astrocytes showed RGC protection replicating the effects seen in the global knockouts. These data implicate astrocyte C3 expression as a critical mediator of retinal neuronal pathology in EAE and MS, and are consistent with recent studies showing C3 gene variants are associated with faster rates of retinal neurodegeneration in human disease.
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158
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Synapse development is regulated by microglial THIK-1 K + channels. Proc Natl Acad Sci U S A 2021; 118:2106294118. [PMID: 34642249 PMCID: PMC8545484 DOI: 10.1073/pnas.2106294118] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/08/2021] [Indexed: 12/17/2022] Open
Abstract
Microglia are the brain’s resident immune cells, surveying the brain with motile processes, which can remove pathogens but also prune unnecessary junctions between the neurons (synapses). A potassium channel, THIK-1, in the microglial membrane allows efflux of potassium from these cells and thereby regulates their membrane voltage as well as their process motility and release of inflammatory mediators. Here, using THIK-1–blocking drugs and THIK-1–deficient mice, we demonstrate that THIK-1 controls removal of synaptic material by microglia, which reduces the number of functional synapses in the developing brain.
Microglia are the resident immune cells of the central nervous system. They constantly survey the brain parenchyma for redundant synapses, debris, or dying cells, which they remove through phagocytosis. Microglial ramification, motility, and cytokine release are regulated by tonically active THIK-1 K+ channels on the microglial plasma membrane. Here, we examined whether these channels also play a role in phagocytosis. Using pharmacological blockers and THIK-1 knockout (KO) mice, we found that a lack of THIK-1 activity approximately halved both microglial phagocytosis and marker levels for the lysosomes that degrade phagocytically removed material. These changes may reflect a decrease of intracellular [Ca2+]i activity, which was observed when THIK-1 activity was reduced, since buffering [Ca2+]i reduced phagocytosis. Less phagocytosis is expected to result in impaired pruning of synapses. In the hippocampus, mice lacking THIK-1 expression had an increased number of anatomically and electrophysiologically defined glutamatergic synapses during development. This resulted from an increased number of presynaptic terminals, caused by impaired removal by THIK-1 KO microglia. The dependence of synapse number on THIK-1 K+ channels, which control microglial surveillance and phagocytic ability, implies that changes in the THIK-1 expression level in disease states may contribute to altering neural circuit function.
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159
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Borst K, Dumas AA, Prinz M. Microglia: Immune and non-immune functions. Immunity 2021; 54:2194-2208. [PMID: 34644556 DOI: 10.1016/j.immuni.2021.09.014] [Citation(s) in RCA: 187] [Impact Index Per Article: 62.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 07/20/2021] [Accepted: 09/16/2021] [Indexed: 12/21/2022]
Abstract
As resident macrophages of the central nervous system (CNS), microglia are associated with diverse functions essential to the developing and adult brain during homeostasis and disease. They are aided in their tasks by intricate bidirectional communication with other brain cells under steady-state conditions as well as with infiltrating peripheral immune cells during perturbations. Harmonious cell-cell communication involving microglia are considered crucial to maintain the healthy state of the tissue environment and to overcome pathology such as neuroinflammation. Analyses of such intercellular pathways have contributed to our understanding of the heterogeneous but context-associated microglial responses to environmental cues across neuropathology, including inflammatory conditions such as infections and autoimmunity, as well as immunosuppressive states as seen in brain tumors. Here, we summarize the latest evidence demonstrating how these interactions drive microglia immune and non-immune functions, which coordinate the transition from homeostatic to disease-related cellular states.
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Affiliation(s)
- Katharina Borst
- Institute of Neuropathology, Medical Faculty, University of Freiburg, Freiburg, Germany.
| | - Anaelle Aurelie Dumas
- Institute of Neuropathology, Medical Faculty, University of Freiburg, Freiburg, Germany.
| | - Marco Prinz
- Institute of Neuropathology, Medical Faculty, University of Freiburg, Freiburg, Germany; Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany; Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany.
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160
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Gomez-Arboledas A, Acharya MM, Tenner AJ. The Role of Complement in Synaptic Pruning and Neurodegeneration. Immunotargets Ther 2021; 10:373-386. [PMID: 34595138 PMCID: PMC8478425 DOI: 10.2147/itt.s305420] [Citation(s) in RCA: 59] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Accepted: 09/04/2021] [Indexed: 12/14/2022] Open
Abstract
The complement system, an essential part of the innate immune system, is composed of a group of secreted and membrane proteins that collectively participate in maintaining the function of the healthy and diseased brain. However, an inappropriate activation of the complement system has been related to an inflammatory response in multiple diseases, such as stroke, traumatic brain injury, multiple sclerosis, and Alzheimer's disease, as well as Zika infection and radiotherapy. In addition, C1q and C3 (initial activation components of the complement cascade) have been shown to play a key beneficial role in the refinement of synaptic circuits during developmental stages and adult plasticity. Nevertheless, excessive synaptic pruning in the adult brain can be detrimental and has been associated with synaptic loss in several pathological conditions. In this brief review, we will discuss the role of the complement system in synaptic pruning as well as its contribution to neurodegeneration and cognitive deficits. We also mention potential therapeutic approaches to target the complement system to treat several neuroinflammatory diseases and unintended consequences of radiotherapy.
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Affiliation(s)
- Angela Gomez-Arboledas
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA, USA
| | - Munjal M Acharya
- Department of Anatomy and Neurobiology, University of California, Irvine, Irvine, CA, USA.,Department of Radiation Oncology, University of California, Irvine, Irvine, CA, USA
| | - Andrea J Tenner
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA, USA.,Department of Neurobiology and Behavior, University of California Irvine, Irvine, CA, USA.,Department of Pathology and Laboratory Medicine, University of California, Irvine, School of Medicine, Irvine, CA, USA
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161
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Complement-associated loss of CA2 inhibitory synapses in the demyelinated hippocampus impairs memory. Acta Neuropathol 2021; 142:643-667. [PMID: 34170374 PMCID: PMC8423657 DOI: 10.1007/s00401-021-02338-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 06/03/2021] [Accepted: 06/14/2021] [Indexed: 12/27/2022]
Abstract
The complement system is implicated in synapse loss in the MS hippocampus, but the functional consequences of synapse loss remain poorly understood. Here, in post-mortem MS hippocampi with demyelination we find that deposits of the complement component C1q are enriched in the CA2 subfield, are linked to loss of inhibitory synapses and are significantly higher in MS patients with cognitive impairments compared to those with preserved cognitive functions. Using the cuprizone mouse model of demyelination, we corroborated that C1q deposits are highest within the demyelinated dorsal hippocampal CA2 pyramidal layer and co-localized with inhibitory synapses engulfed by microglia/macrophages. In agreement with the loss of inhibitory perisomatic synapses, we found that Schaffer collateral feedforward inhibition but not excitation was impaired in CA2 pyramidal neurons and accompanied by intrinsic changes and a reduced spike output. Finally, consistent with excitability deficits, we show that cuprizone-treated mice exhibit impaired encoding of social memories. Together, our findings identify CA2 as a critical circuit in demyelinated intrahippocampal lesions and memory dysfunctions in MS.
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162
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Sullivan G, Galdi P, Borbye-Lorenzen N, Stoye DQ, Lamb GJ, Evans MJ, Skogstrand K, Chandran S, Boardman JP. Preterm Birth Is Associated With Immune Dysregulation Which Persists in Infants Exposed to Histologic Chorioamnionitis. Front Immunol 2021; 12:722489. [PMID: 34512648 PMCID: PMC8430209 DOI: 10.3389/fimmu.2021.722489] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 08/09/2021] [Indexed: 01/19/2023] Open
Abstract
Introduction Preterm infants are at increased risk of exposure to histologic chorioamnionitis (HCA) when compared to term-born controls, and this is associated with several neonatal morbidities involving brain, lungs and gut. Preterm infants could benefit from immunomodulatory therapies in the perinatal period, but development of rational treatment strategies requires improved characterization of the perinatal response to HCA. We had two objectives: The first, to characterize the umbilical cord blood immune profile in preterm infants compared to term-born controls; the second, to investigate the postnatal immune response in preterm infants exposed to HCA versus those who were not. Population For objective one 59 term infants [mean gestational age (GA) 39+4 (37+3 to 42+0)] and 55 preterm infants [mean GA29+0(23+3 to 32+0)] with umbilical cord samples available were included; for objective two we studied 96 preterm infants [mean GA29+1(23+2 to 32+0)] for whom placental histology and postnatal blood samples were available. Methods Placental histopathology was used to identify reaction patterns indicative of HCA, and a customized immunoassay of 24 inflammatory markers and trophic proteins selected to reflect the perinatal immune response was performed on umbilical cord blood in term and preterm participants and postnatal day 5 blood in the preterm group. Results The umbilical cord blood immune profile classified gestational age category with 86% accuracy (95% CI 0.78-0.92), p-value=1.242x10-14. Pro-inflammatory proteins IL-6, MCP-1 and CRP were elevated in the cord blood of preterm infants whilst BDNF, C3, C9, IL-18, MMP-9 and RANTES were decreased, compared to infants born at term. In preterm infants, exposure to HCA was associated with elevations in 8 immune proteins on postnatal day 5 (BDNF, C3, C5a, C9, IL-8, MCP-1, MIP-1β and MMP-9) when compared to preterm infants who were not exposed. Conclusion Preterm birth is associated with a distinct immune profile in umbilical cord blood and preterm infants exposed to HCA with evidence of a fetal inflammatory response have specific alterations in immune function that are apparent on day 5 of postnatal life.
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Affiliation(s)
- Gemma Sullivan
- Medical Research Council (MRC) Centre for Reproductive Health, University of Edinburgh, Edinburgh, United Kingdom
| | - Paola Galdi
- Medical Research Council (MRC) Centre for Reproductive Health, University of Edinburgh, Edinburgh, United Kingdom
| | - Nis Borbye-Lorenzen
- Danish Center for Neonatal Screening, Statens Serum Institut, Copenhagen, Denmark
| | - David Q Stoye
- Medical Research Council (MRC) Centre for Reproductive Health, University of Edinburgh, Edinburgh, United Kingdom
| | - Gillian J Lamb
- Medical Research Council (MRC) Centre for Reproductive Health, University of Edinburgh, Edinburgh, United Kingdom
| | - Margaret J Evans
- Department of Pathology, Royal Infirmary of Edinburgh, Edinburgh, United Kingdom
| | - Kristin Skogstrand
- Danish Center for Neonatal Screening, Statens Serum Institut, Copenhagen, Denmark
| | - Siddharthan Chandran
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom.,Medical Research Council (MRC) Centre for Regenerative Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - James P Boardman
- Medical Research Council (MRC) Centre for Reproductive Health, University of Edinburgh, Edinburgh, United Kingdom.,Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
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163
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Bellingacci L, Mancini A, Gaetani L, Tozzi A, Parnetti L, Di Filippo M. Synaptic Dysfunction in Multiple Sclerosis: A Red Thread from Inflammation to Network Disconnection. Int J Mol Sci 2021; 22:ijms22189753. [PMID: 34575917 PMCID: PMC8469646 DOI: 10.3390/ijms22189753] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 08/31/2021] [Accepted: 09/03/2021] [Indexed: 12/24/2022] Open
Abstract
Multiple sclerosis (MS) has been clinically considered a chronic inflammatory disease of the white matter; however, in the last decade growing evidence supported an important role of gray matter pathology as a major contributor of MS-related disability and the involvement of synaptic structures assumed a key role in the pathophysiology of the disease. Synaptic contacts are considered central units in the information flow, involved in synaptic transmission and plasticity, critical processes for the shaping and functioning of brain networks. During the course of MS, the immune system and its diffusible mediators interact with synaptic structures leading to changes in their structure and function, influencing brain network dynamics. The purpose of this review is to provide an overview of the existing literature on synaptic involvement during experimental and human MS, in order to understand the mechanisms by which synaptic failure eventually leads to brain networks alterations and contributes to disabling MS symptoms and disease progression.
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Affiliation(s)
- Laura Bellingacci
- Section of Neurology, Department of Medicine and Surgery, University of Perugia, 06132 Perugia, Italy; (L.B.); (A.M.); (L.G.); (L.P.)
| | - Andrea Mancini
- Section of Neurology, Department of Medicine and Surgery, University of Perugia, 06132 Perugia, Italy; (L.B.); (A.M.); (L.G.); (L.P.)
| | - Lorenzo Gaetani
- Section of Neurology, Department of Medicine and Surgery, University of Perugia, 06132 Perugia, Italy; (L.B.); (A.M.); (L.G.); (L.P.)
| | - Alessandro Tozzi
- Section of Physiology and Biochemistry, Department of Medicine and Surgery, University of Perugia, 06132 Perugia, Italy;
| | - Lucilla Parnetti
- Section of Neurology, Department of Medicine and Surgery, University of Perugia, 06132 Perugia, Italy; (L.B.); (A.M.); (L.G.); (L.P.)
| | - Massimiliano Di Filippo
- Section of Neurology, Department of Medicine and Surgery, University of Perugia, 06132 Perugia, Italy; (L.B.); (A.M.); (L.G.); (L.P.)
- Correspondence: ; Tel.: +39-075-578-3830
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164
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Absinta M, Maric D, Gharagozloo M, Garton T, Smith MD, Jin J, Fitzgerald KC, Song A, Liu P, Lin JP, Wu T, Johnson KR, McGavern DB, Schafer DP, Calabresi PA, Reich DS. A lymphocyte-microglia-astrocyte axis in chronic active multiple sclerosis. Nature 2021; 597:709-714. [PMID: 34497421 PMCID: PMC8719282 DOI: 10.1038/s41586-021-03892-7] [Citation(s) in RCA: 283] [Impact Index Per Article: 94.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 08/10/2021] [Indexed: 12/20/2022]
Abstract
Multiple sclerosis (MS) lesions that do not resolve in the months after they form harbour ongoing demyelination and axon degeneration, and are identifiable in vivo by their paramagnetic rims on MRI scans1-3. Here, to define mechanisms underlying this disabling, progressive neurodegenerative state4-6 and foster development of new therapeutic agents, we used MRI-informed single-nucleus RNA sequencing to profile the edge of demyelinated white matter lesions at various stages of inflammation. We uncovered notable glial and immune cell diversity, especially at the chronically inflamed lesion edge. We define 'microglia inflamed in MS' (MIMS) and 'astrocytes inflamed in MS', glial phenotypes that demonstrate neurodegenerative programming. The MIMS transcriptional profile overlaps with that of microglia in other neurodegenerative diseases, suggesting that primary and secondary neurodegeneration share common mechanisms and could benefit from similar therapeutic approaches. We identify complement component 1q (C1q) as a critical mediator of MIMS activation, validated immunohistochemically in MS tissue, genetically by microglia-specific C1q ablation in mice with experimental autoimmune encephalomyelitis, and therapeutically by treating chronic experimental autoimmune encephalomyelitis with C1q blockade. C1q inhibition is a potential therapeutic avenue to address chronic white matter inflammation, which could be monitored by longitudinal assessment of its dynamic biomarker, paramagnetic rim lesions, using advanced MRI methods.
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Affiliation(s)
- Martina Absinta
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
- Translational Neuroradiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA.
- IRCCS San Raffaele Hospital and Vita-Salute San Raffaele University, Milan, Italy.
| | - Dragan Maric
- Flow and Imaging Cytometry Core Facility, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Marjan Gharagozloo
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Thomas Garton
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Matthew D Smith
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jing Jin
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Kathryn C Fitzgerald
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Anya Song
- Department of Neurobiology and the Brudnik Neuropsychiatry Institute, University of Massachusetts Medical School, Worcester, MA, USA
| | - Poching Liu
- DNA Sequencing and Genomics Core, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Jing-Ping Lin
- Translational Neuroradiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Tianxia Wu
- Clinical Trials Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Kory R Johnson
- Bioinformatics Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Dorian B McGavern
- Viral Immunology and Intravital Imaging Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Dorothy P Schafer
- Department of Neurobiology and the Brudnik Neuropsychiatry Institute, University of Massachusetts Medical School, Worcester, MA, USA
| | - Peter A Calabresi
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Daniel S Reich
- Translational Neuroradiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA.
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165
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Cao P, Chen C, Liu A, Shan Q, Zhu X, Jia C, Peng X, Zhang M, Farzinpour Z, Zhou W, Wang H, Zhou JN, Song X, Wang L, Tao W, Zheng C, Zhang Y, Ding YQ, Jin Y, Xu L, Zhang Z. Early-life inflammation promotes depressive symptoms in adolescence via microglial engulfment of dendritic spines. Neuron 2021; 109:2573-2589.e9. [PMID: 34233151 DOI: 10.1016/j.neuron.2021.06.012] [Citation(s) in RCA: 141] [Impact Index Per Article: 47.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 05/02/2021] [Accepted: 06/10/2021] [Indexed: 02/07/2023]
Abstract
Early-life inflammation increases the risk for depression in later life. Here, we demonstrate how early-life inflammation causes adolescent depressive-like symptoms: by altering the long-term neuronal spine engulfment capacity of microglia. For mice exposed to lipopolysaccharide (LPS)-induced inflammation via the Toll-like receptor 4/NF-κB signaling pathway at postnatal day (P) 14, ongoing longitudinal imaging of the living brain revealed that later stress (delivered during adolescence on P45) increases the extent of microglial engulfment around anterior cingulate cortex (ACC) glutamatergic neuronal (ACCGlu) spines. When the ACC microglia of LPS-treated mice were deleted or chemically inhibited, the mice did not exhibit depressive-like behaviors during adolescence. Moreover, we show that the fractalkine receptor CX3CR1 mediates stress-induced engulfment of ACCGlu neuronal spines. Together, our findings establish that early-life inflammation causes dysregulation of microglial engulfment capacity, which encodes long-lasting maladaptation of ACCGlu neurons to stress, thus promoting development of depression-like symptoms during adolescence.
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Affiliation(s)
- Peng Cao
- Department of Anesthesiology, The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at the Microscale, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230036, China
| | - Changmao Chen
- Department of Anesthesiology, The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at the Microscale, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230036, China
| | - An Liu
- Department of Physiology, School of Basic Medical Sciences, Anhui Medical University, Hefei 230022, China
| | - Qinghong Shan
- Department of Anesthesiology, The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at the Microscale, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230036, China
| | - Xia Zhu
- Department of Anesthesiology, The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at the Microscale, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230036, China
| | - Chunhui Jia
- Department of Anesthesiology, The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at the Microscale, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230036, China
| | - Xiaoqi Peng
- Department of Anesthesiology, The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at the Microscale, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230036, China
| | - Mingjun Zhang
- Department of Anesthesiology, The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at the Microscale, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230036, China
| | - Zahra Farzinpour
- Department of Anesthesiology, The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at the Microscale, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230036, China
| | - Wenjie Zhou
- Department of Anesthesiology, The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at the Microscale, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230036, China
| | - Haitao Wang
- Department of Anesthesiology, The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at the Microscale, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230036, China
| | - Jiang-Ning Zhou
- Department of Anesthesiology, The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at the Microscale, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230036, China
| | - Xiaoyuan Song
- Department of Anesthesiology, The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at the Microscale, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230036, China
| | - Liecheng Wang
- Department of Physiology, School of Basic Medical Sciences, Anhui Medical University, Hefei 230022, China
| | - Wenjuan Tao
- Department of Physiology, School of Basic Medical Sciences, Anhui Medical University, Hefei 230022, China
| | - Changjian Zheng
- Department of Anesthesiology, the First Affiliated Hospital of Wannan Medical College, Wuhu 241002, China
| | - Yan Zhang
- Stroke Center & Department of Neurology, the First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230036, China
| | - Yu-Qiang Ding
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, and Department of Laboratory Animal Science, Fudan University, Shanghai 200032, China
| | - Yan Jin
- Department of Anesthesiology, The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at the Microscale, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230036, China.
| | - Lin Xu
- Key Laboratory of Animal Models and Human Disease Mechanisms, and Laboratory of Learning and Memory, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China.
| | - Zhi Zhang
- Department of Anesthesiology, The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at the Microscale, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230036, China.
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166
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Call CL, Bergles DE. Cortical neurons exhibit diverse myelination patterns that scale between mouse brain regions and regenerate after demyelination. Nat Commun 2021; 12:4767. [PMID: 34362912 PMCID: PMC8346564 DOI: 10.1038/s41467-021-25035-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 07/16/2021] [Indexed: 12/04/2022] Open
Abstract
Axons in the cerebral cortex show a broad range of myelin coverage. Oligodendrocytes establish this pattern by selecting a cohort of axons for myelination; however, the distribution of myelin on distinct neurons and extent of internode replacement after demyelination remain to be defined. Here we show that myelination patterns of seven distinct neuron subtypes in somatosensory cortex are influenced by both axon diameter and neuronal identity. Preference for myelination of parvalbumin interneurons was preserved between cortical areas with varying myelin density, suggesting that regional differences in myelin abundance arises through local control of oligodendrogenesis. By imaging loss and regeneration of myelin sheaths in vivo we show that myelin distribution on individual axons was altered but overall myelin content on distinct neuron subtypes was restored. Our findings suggest that local changes in myelination are tolerated, allowing regenerated oligodendrocytes to restore myelin content on distinct neurons through opportunistic selection of axons. Myelination patterns of different neurons in grey matter have not been fully defined. Here, the authors show that axon diameter and neuronal identity influence myelination patterns in the intact mouse somatosensory cortex. In vivo imaging revealed that remyelination altered myelin patterns but restored overall myelin content on distinct neuron subtypes.
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Affiliation(s)
- Cody L Call
- The Solomon Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD, USA
| | - Dwight E Bergles
- The Solomon Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD, USA. .,Johns Hopkins University, Kavli Neuroscience Discovery Institute, Baltimore, MD, USA.
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167
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Tsouki F, Williams A. Multifaceted involvement of microglia in gray matter pathology in multiple sclerosis. Stem Cells 2021; 39:993-1007. [PMID: 33754376 DOI: 10.1002/stem.3374] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 03/01/2021] [Indexed: 06/12/2023]
Abstract
In the inflammatory demyelinating neurodegenerative disease multiple sclerosis (MS), there is increasing interest in gray matter pathology, as neuronal loss and cortical atrophy correlate with disability and disease progression, and MS therapeutics fail to significantly slow or stop neurodegeneration. Microglia, the central nervous system (CNS)-resident macrophages, are extensively involved in white matter MS pathology, but are also implicated in gray matter pathology, similar to other neurodegenerative diseases, for which there is synaptic, axonal, and neuronal degeneration. Microglia display regional heterogeneity within the CNS, which reflects their highly plastic nature and their ability to deliver context-dependent responses tailored to the demands of their microenvironment. Therefore, microglial roles in the MS gray matter in part reflect and in part diverge from those in the white matter. The present review summarizes current knowledge of microglial involvement in gray matter changes in MS, in demyelination, synaptic damage, and neurodegeneration, with evidence implicating microglia in pathology, neuroprotection, and repair. As our understanding of microglial physiology and pathophysiology increases, we describe how we are moving toward potential therapeutic applications in MS, harnessing microglia to protect and regenerate the CNS.
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Affiliation(s)
- Foteini Tsouki
- Centre for Regenerative Medicine, Institute for Regeneration and Repair, The University of Edinburgh, Edinburgh BioQuarter, Edinburgh, UK
| | - Anna Williams
- Centre for Regenerative Medicine, Institute for Regeneration and Repair, The University of Edinburgh, Edinburgh BioQuarter, Edinburgh, UK
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168
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Kalafatakis I, Karagogeos D. Oligodendrocytes and Microglia: Key Players in Myelin Development, Damage and Repair. Biomolecules 2021; 11:1058. [PMID: 34356682 PMCID: PMC8301746 DOI: 10.3390/biom11071058] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Revised: 07/16/2021] [Accepted: 07/16/2021] [Indexed: 12/13/2022] Open
Abstract
Oligodendrocytes, the myelin-making cells of the CNS, regulate the complex process of myelination under physiological and pathological conditions, significantly aided by other glial cell types such as microglia, the brain-resident, macrophage-like innate immune cells. In this review, we summarize how oligodendrocytes orchestrate myelination, and especially myelin repair after damage, and present novel aspects of oligodendroglial functions. We emphasize the contribution of microglia in the generation and regeneration of myelin by discussing their beneficial and detrimental roles, especially in remyelination, underlining the cellular and molecular components involved. Finally, we present recent findings towards human stem cell-derived preclinical models for the study of microglia in human pathologies and on the role of microbiome on glial cell functions.
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Affiliation(s)
- Ilias Kalafatakis
- Laboratory of Neuroscience, Department of Basic Science, University of Crete Medical School, 70013 Heraklion, Greece;
- IMBB FORTH, Nikolaou Plastira 100, Vassilika Vouton, 70013 Heraklion, Greece
| | - Domna Karagogeos
- Laboratory of Neuroscience, Department of Basic Science, University of Crete Medical School, 70013 Heraklion, Greece;
- IMBB FORTH, Nikolaou Plastira 100, Vassilika Vouton, 70013 Heraklion, Greece
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169
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Gharagozloo M, Smith MD, Sotirchos ES, Jin J, Meyers K, Taylor M, Garton T, Bannon R, Lord HN, Dawson TM, Dawson VL, Lee S, Calabresi PA. Therapeutic Potential of a Novel Glucagon-like Peptide-1 Receptor Agonist, NLY01, in Experimental Autoimmune Encephalomyelitis. Neurotherapeutics 2021; 18:1834-1848. [PMID: 34260042 PMCID: PMC8608955 DOI: 10.1007/s13311-021-01088-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/02/2021] [Indexed: 02/04/2023] Open
Abstract
Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS), characterized by demyelination, gliosis, and neurodegeneration. While the currently available disease-modifying therapies effectively suppress the immune attack on the CNS, there are no therapies to date that directly mitigate neurodegeneration. Glucagon-like peptide-1 (GLP-1) is a small peptide hormone that maintains glucose homeostasis. A novel GLP-1 receptor (GLP-1R) agonist, NLY01, was recently shown to have neuroprotective effects in the animal models of Parkinson's disease and is now in a phase 2 clinical trial. In this study, we investigated the therapeutic potential of NLY01 in a mouse model of MS, experimental autoimmune encephalomyelitis (EAE). Our data show that NLY01 delays the onset and attenuates the severity of EAE in a prevention paradigm, when given before disease onset. NLY01 inhibits the activation of immune cells in the spleen and reduces their trafficking into the CNS. In addition, we show that NLY01 suppresses the production of chemokines that are involved in leukocyte recruitment to the site of inflammation. The anti-inflammatory effect of NLY01 at the early stage of EAE may block the expression of the genes associated with neurotoxic astrocytes in the optic nerves, thereby preventing retinal ganglion cell (RGC) loss in the progressive stage of EAE. In the therapeutic paradigm, NLY01 significantly decreases the clinical score and second attack in a model of relapsing-remitting EAE. GLP-1R agonists may have dual efficacy in MS by suppressing peripheral and CNS inflammation, thereby limiting neuronal loss.
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Affiliation(s)
| | | | | | - Jing Jin
- Department of Neurology, Johns Hopkins, Baltimore, MD, USA
| | - Keya Meyers
- Department of Neurology, Johns Hopkins, Baltimore, MD, USA
| | | | - Thomas Garton
- Department of Neurology, Johns Hopkins, Baltimore, MD, USA
| | - Riley Bannon
- Department of Neurology, Johns Hopkins, Baltimore, MD, USA
| | | | - Ted M Dawson
- Department of Neurology, Johns Hopkins, Baltimore, MD, USA
- Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Valina L Dawson
- Department of Neurology, Johns Hopkins, Baltimore, MD, USA
- Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | | | - Peter A Calabresi
- Department of Neurology, Johns Hopkins, Baltimore, MD, USA.
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
- Division of Neuroimmunology and Neurological Infections, Johns Hopkins Hospital, 600 N. Wolfe St, Baltimore, MD, 21287, USA.
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170
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Ferro A, Auguste YSS, Cheadle L. Microglia, Cytokines, and Neural Activity: Unexpected Interactions in Brain Development and Function. Front Immunol 2021; 12:703527. [PMID: 34276699 PMCID: PMC8281303 DOI: 10.3389/fimmu.2021.703527] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 06/11/2021] [Indexed: 12/01/2022] Open
Abstract
Intercellular signaling molecules such as cytokines and their receptors enable immune cells to communicate with one another and their surrounding microenvironments. Emerging evidence suggests that the same signaling pathways that regulate inflammatory responses to injury and disease outside of the brain also play powerful roles in brain development, plasticity, and function. These observations raise the question of how the same signaling molecules can play such distinct roles in peripheral tissues compared to the central nervous system, a system previously thought to be largely protected from inflammatory signaling. Here, we review evidence that the specialized roles of immune signaling molecules such as cytokines in the brain are to a large extent shaped by neural activity, a key feature of the brain that reflects active communication between neurons at synapses. We discuss the known mechanisms through which microglia, the resident immune cells of the brain, respond to increases and decreases in activity by engaging classical inflammatory signaling cascades to assemble, remodel, and eliminate synapses across the lifespan. We integrate evidence from (1) in vivo imaging studies of microglia-neuron interactions, (2) developmental studies across multiple neural circuits, and (3) molecular studies of activity-dependent gene expression in microglia and neurons to highlight the specific roles of activity in defining immune pathway function in the brain. Given that the repurposing of signaling pathways across different tissues may be an important evolutionary strategy to overcome the limited size of the genome, understanding how cytokine function is established and maintained in the brain could lead to key insights into neurological health and disease.
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Affiliation(s)
| | | | - Lucas Cheadle
- Neuroscience Department, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, United States
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171
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De Schepper S, Crowley G, Hong S. Understanding microglial diversity and implications for neuronal function in health and disease. Dev Neurobiol 2021; 81:507-523. [PMID: 32757416 PMCID: PMC8438703 DOI: 10.1002/dneu.22777] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 06/21/2020] [Accepted: 07/31/2020] [Indexed: 12/22/2022]
Abstract
Genetic data implicate microglia as central players in brain health and disease, urging the need to better understand what microglia do in the brain. Microglia are critical partners in neuronal wiring and function during development and disease. Emerging literature suggests that microglia have diverse functional roles, raising the intriguing question of which functions of microglia become impaired in disease to undermine proper neuronal function. It is also becoming increasingly clear that microglia exist in heterogeneous cell states. Microglial cell states appear context-dependent, that is, age, sex, location, and health of their microenvironment; these are further influenced by external signaling factors including gut microbiota and lipid metabolites. These data altogether suggest that microglia exist in functional clusters that impact, and are impacted by, surrounding neuronal microenvironment. However, we still lack understanding of how we can translate microglia cell states into function. Here, we summarize the state-of-the-art on the diverse functions of microglia in relation to neuronal health. Then, we discuss heterogeneity during developing, healthy adult and diseased brains, and whether this may be predetermined by origin and/or regulated by local milieu. Finally, we propose that it is critical to gain high-resolution functional discernment into microglia-neuron interactions while preserving the spatial architecture of the tissue. Such insight will reveal specific targets for biomarker and therapeutic development toward microglia-neuron crosstalk in disease.
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Affiliation(s)
| | - Gerard Crowley
- UK Dementia Research InstituteUniversity College LondonLondonUK
| | - Soyon Hong
- UK Dementia Research InstituteUniversity College LondonLondonUK
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172
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Huang S, Chen T, Suo Q, Shi R, Khan H, Ma Y, Tang Y, Yang GY, Zhang Z. BK Channel-Mediated Microglial Phagocytosis Alleviates Neurological Deficit After Ischemic Stroke. Front Cell Neurosci 2021; 15:683769. [PMID: 34276309 PMCID: PMC8281043 DOI: 10.3389/fncel.2021.683769] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 05/25/2021] [Indexed: 11/16/2022] Open
Abstract
Microglial phagocytosis benefits neurological recovery after stroke. Large-conductance Ca2+-activated K+ currents are expressed in activated microglia, and BK channel knockout aggravates cerebral ischemic injury. However, the effect of BK channels on microglial phagocytosis after ischemic stroke remains unknown. Here, we explored whether BK channel activation is beneficial for neurological outcomes through microglial phagocytosis after ischemic stroke. ICR mice after transient middle cerebral artery occlusion (tMCAO) were treated with dimethyl sulfoxide (DMSO), BK channel activator NS19504, and inhibitor Paxilline. The results showed a decrease in BK channel expression after tMCAO. BK channel activator NS19504 alleviates neurological deficit after experimental modeling of tMCAO in mice compared to the control. Furthermore, we treated primary microglia with DMSO, NS19504, and Paxilline after oxygen glucose deprivation (OGD). NS19504 promoted primary microglial phagocytosing fluorescent beads and neuronal debris, which reduced neuronal apoptosis after stroke. These effects could be reversed by BK channel inhibitor Paxilline. Finally, NS19504 increased relative phosphorylated extracellular signal-regulated kinase 1/2 expression compared to the Paxilline group at the third day after stroke. Our findings indicate that microglial BK channels are a potential target for acute stage of ischemic stroke therapy.
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Affiliation(s)
- Shuxian Huang
- Shanghai Jiao Tong University Affiliated Sixth People's Hospital, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Tingting Chen
- Shanghai Jiao Tong University Affiliated Sixth People's Hospital, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Qian Suo
- Shanghai Jiao Tong University Affiliated Sixth People's Hospital, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Rubing Shi
- Shanghai Jiao Tong University Affiliated Sixth People's Hospital, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Haroon Khan
- Shanghai Jiao Tong University Affiliated Sixth People's Hospital, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Yuanyuan Ma
- Shanghai Jiao Tong University Affiliated Sixth People's Hospital, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China.,Department of Neurology, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Yaohui Tang
- Shanghai Jiao Tong University Affiliated Sixth People's Hospital, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Guo-Yuan Yang
- Shanghai Jiao Tong University Affiliated Sixth People's Hospital, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China.,Department of Neurology, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Zhijun Zhang
- Shanghai Jiao Tong University Affiliated Sixth People's Hospital, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
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173
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Vercellino M, Marasciulo S, Grifoni S, Vallino-Costassa E, Bosa C, Pasanisi MB, Crociara P, Casalone C, Chiò A, Giordana MT, Corona C, Cavalla P. Acute and chronic synaptic pathology in multiple sclerosis gray matter. Mult Scler 2021; 28:369-382. [PMID: 34124960 DOI: 10.1177/13524585211022174] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVES To investigate the extent of synaptic loss, and the contribution of gray matter (GM) inflammation and demyelination to synaptic loss, in multiple sclerosis (MS) brain tissue. METHODS This study was performed on two different post-mortem series of MS and control brains, including deep GM and cortical GM. MS brain samples had been specifically selected for the presence of active demyelinating GM lesions. Over 1,000,000 individual synapses were identified and counted using confocal microscopy, and further characterized as glutamatergic/GABAergic. Synaptic counts were also correlated with neuronal/axonal loss. RESULTS Important synaptic loss was observed in active demyelinating GM lesions (-58.9%), while in chronic inactive GM lesions, synaptic density was only mildly reduced compared to adjacent non-lesional gray matter (NLGM) (-12.6%). Synaptic loss equally affected glutamatergic and GABAergic synapses. Diffuse synaptic loss was observed in MS NLGM compared to control GM (-21.2% overall). CONCLUSION This study provides evidence, in MS brain tissue, of acute synaptic damage/loss during active GM inflammatory demyelination and of synaptic reorganization in chronically demyelinated GM, affecting equally glutamatergic and GABAergic synapses. Furthermore, this study provides a strong indication of widespread synaptic loss in MS NLGM also independently from focal GM demyelination.
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Affiliation(s)
- Marco Vercellino
- I Division of Neurology and Multiple Sclerosis Center, Department of Neurosciences and Mental Health, AOU Città della Salute e della Scienza di Torino, Turin, Italy
| | - Stella Marasciulo
- "Rita Levi Montalcini" Department of Neuroscience, University of Turin, Turin, Italy
| | - Silvia Grifoni
- S.S. Neurobiologia Sperimentale, Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Turin, Italy
| | - Elena Vallino-Costassa
- S.S. Neurobiologia Sperimentale, Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Turin, Italy
| | - Chiara Bosa
- "Rita Levi Montalcini" Department of Neuroscience, University of Turin, Turin, Italy
| | | | - Paola Crociara
- S.S. Neurobiologia Sperimentale, Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Turin, Italy
| | - Cristina Casalone
- S.S. Neurobiologia Sperimentale, Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Turin, Italy
| | - Adriano Chiò
- I Division of Neurology and Multiple Sclerosis Center, Department of Neurosciences and Mental Health, AOU Città della Salute e della Scienza di Torino, Turin, Italy/"Rita Levi Montalcini" Department of Neuroscience, University of Turin, Turin, Italy/Neuroscience Institute of Torino (NIT), Turin, Italy
| | - Maria Teresa Giordana
- "Rita Levi Montalcini" Department of Neuroscience, University of Turin, Turin, Italy
| | - Cristiano Corona
- S.S. Neurobiologia Sperimentale, Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Turin, Italy
| | - Paola Cavalla
- I Division of Neurology and Multiple Sclerosis Center, Department of Neurosciences and Mental Health, AOU Città della Salute e della Scienza di Torino, Turin, Italy
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174
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van Olst L, Rodriguez-Mogeda C, Picon C, Kiljan S, James RE, Kamermans A, van der Pol SMA, Knoop L, Michailidou I, Drost E, Franssen M, Schenk GJ, Geurts JJG, Amor S, Mazarakis ND, van Horssen J, de Vries HE, Reynolds R, Witte ME. Meningeal inflammation in multiple sclerosis induces phenotypic changes in cortical microglia that differentially associate with neurodegeneration. Acta Neuropathol 2021; 141:881-899. [PMID: 33779783 PMCID: PMC8113309 DOI: 10.1007/s00401-021-02293-4] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 02/15/2021] [Accepted: 03/03/2021] [Indexed: 12/21/2022]
Abstract
Meningeal inflammation strongly associates with demyelination and neuronal loss in the underlying cortex of progressive MS patients, thereby contributing significantly to clinical disability. However, the pathological mechanisms of meningeal inflammation-induced cortical pathology are still largely elusive. By extensive analysis of cortical microglia in post-mortem progressive MS tissue, we identified cortical areas with two MS-specific microglial populations, termed MS1 and MS2 cortex. The microglial population in MS1 cortex was characterized by a higher density and increased expression of the activation markers HLA class II and CD68, whereas microglia in MS2 cortex showed increased morphological complexity and loss of P2Y12 and TMEM119 expression. Interestingly, both populations associated with inflammation of the overlying meninges and were time-dependently replicated in an in vivo rat model for progressive MS-like chronic meningeal inflammation. In this recently developed animal model, cortical microglia at 1-month post-induction of experimental meningeal inflammation resembled microglia in MS1 cortex, and microglia at 2 months post-induction acquired a MS2-like phenotype. Furthermore, we observed that MS1 microglia in both MS cortex and the animal model were found closely apposing neuronal cell bodies and to mediate pre-synaptic displacement and phagocytosis, which coincided with a relative sparing of neurons. In contrast, microglia in MS2 cortex were not involved in these synaptic alterations, but instead associated with substantial neuronal loss. Taken together, our results show that in response to meningeal inflammation, microglia acquire two distinct phenotypes that differentially associate with neurodegeneration in the progressive MS cortex. Furthermore, our in vivo data suggests that microglia initially protect neurons from meningeal inflammation-induced cell death by removing pre-synapses from the neuronal soma, but eventually lose these protective properties contributing to neuronal loss.
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Affiliation(s)
- Lynn van Olst
- Department of Molecular Cell Biology and Immunology, Amsterdam UMC, MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam, Netherlands
| | - Carla Rodriguez-Mogeda
- Department of Molecular Cell Biology and Immunology, Amsterdam UMC, MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam, Netherlands
| | - Carmen Picon
- Division of Neuroscience, Department of Brain Sciences, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK
| | - Svenja Kiljan
- Department of Anatomy and Neurosciences, Amsterdam UMC, MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam, Netherlands
| | - Rachel E James
- Division of Neuroscience, Department of Brain Sciences, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK
| | - Alwin Kamermans
- Department of Molecular Cell Biology and Immunology, Amsterdam UMC, MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam, Netherlands
| | - Susanne M A van der Pol
- Department of Molecular Cell Biology and Immunology, Amsterdam UMC, MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam, Netherlands
| | - Lydian Knoop
- Department of Pathology, Amsterdam UMC, MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam, Netherlands
| | - Iliana Michailidou
- Department of Clinical Genetics, Leiden University Medical Center, Leiden, Netherlands
| | - Evelien Drost
- Department of Molecular Cell Biology and Immunology, Amsterdam UMC, MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam, Netherlands
| | - Marc Franssen
- Department of Molecular Cell Biology and Immunology, Amsterdam UMC, MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam, Netherlands
| | - Geert J Schenk
- Department of Anatomy and Neurosciences, Amsterdam UMC, MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam, Netherlands
| | - Jeroen J G Geurts
- Department of Anatomy and Neurosciences, Amsterdam UMC, MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam, Netherlands
| | - Sandra Amor
- Department of Pathology, Amsterdam UMC, MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam, Netherlands
| | - Nicholas D Mazarakis
- Division of Neuroscience, Department of Brain Sciences, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK
| | - Jack van Horssen
- Department of Molecular Cell Biology and Immunology, Amsterdam UMC, MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam, Netherlands
| | - Helga E de Vries
- Department of Molecular Cell Biology and Immunology, Amsterdam UMC, MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam, Netherlands
- Department of Medical Biochemistry, Amsterdam UMC, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| | - Richard Reynolds
- Division of Neuroscience, Department of Brain Sciences, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK.
- Centre for Molecular Neuropathology, LKC School of Medicine, Nanyang Technological University, Singapore, Singapore.
| | - Maarten E Witte
- Department of Molecular Cell Biology and Immunology, Amsterdam UMC, MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam, Netherlands.
- Department of Pathology, Amsterdam UMC, MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam, Netherlands.
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175
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Clark IC, Gutiérrez-Vázquez C, Wheeler MA, Li Z, Rothhammer V, Linnerbauer M, Sanmarco LM, Guo L, Blain M, Zandee SEJ, Chao CC, Batterman KV, Schwabenland M, Lotfy P, Tejeda-Velarde A, Hewson P, Manganeli Polonio C, Shultis MW, Salem Y, Tjon EC, Fonseca-Castro PH, Borucki DM, Alves de Lima K, Plasencia A, Abate AR, Rosene DL, Hodgetts KJ, Prinz M, Antel JP, Prat A, Quintana FJ. Barcoded viral tracing of single-cell interactions in central nervous system inflammation. Science 2021; 372:372/6540/eabf1230. [PMID: 33888612 DOI: 10.1126/science.abf1230] [Citation(s) in RCA: 123] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 01/27/2021] [Accepted: 03/12/2021] [Indexed: 12/11/2022]
Abstract
Cell-cell interactions control the physiology and pathology of the central nervous system (CNS). To study astrocyte cell interactions in vivo, we developed rabies barcode interaction detection followed by sequencing (RABID-seq), which combines barcoded viral tracing and single-cell RNA sequencing (scRNA-seq). Using RABID-seq, we identified axon guidance molecules as candidate mediators of microglia-astrocyte interactions that promote CNS pathology in experimental autoimmune encephalomyelitis (EAE) and, potentially, multiple sclerosis (MS). In vivo cell-specific genetic perturbation EAE studies, in vitro systems, and the analysis of MS scRNA-seq datasets and CNS tissue established that Sema4D and Ephrin-B3 expressed in microglia control astrocyte responses via PlexinB2 and EphB3, respectively. Furthermore, a CNS-penetrant EphB3 inhibitor suppressed astrocyte and microglia proinflammatory responses and ameliorated EAE. In summary, RABID-seq identified microglia-astrocyte interactions and candidate therapeutic targets.
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Affiliation(s)
- Iain C Clark
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA.,Department of Bioengineering, University of California, Berkeley, California Institute for Quantitative Biosciences, Berkeley, CA 94720, USA
| | - Cristina Gutiérrez-Vázquez
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Michael A Wheeler
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA.,Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Zhaorong Li
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA.,Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Veit Rothhammer
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA.,Department of Neurology, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Mathias Linnerbauer
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA.,Department of Neurology, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Liliana M Sanmarco
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Lydia Guo
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Manon Blain
- Neuroimmunology Unit, Montreal Neurological Institute, Department of Neurology and Neurosurgery, McGill University, Montreal, QC H3A 2B4, Canada
| | - Stephanie E J Zandee
- Neuroimmunology Research Laboratory, Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, QC H2X 0A9, Canada
| | - Chun-Cheih Chao
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Katelyn V Batterman
- Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, MA 02118, USA
| | - Marius Schwabenland
- Institute of Neuropathology, University of Freiburg, D-79106 Freiburg, Germany
| | - Peter Lotfy
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA.,Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Amalia Tejeda-Velarde
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Patrick Hewson
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Carolina Manganeli Polonio
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Michael W Shultis
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Yasmin Salem
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Emily C Tjon
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Pedro H Fonseca-Castro
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Davis M Borucki
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Kalil Alves de Lima
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Agustin Plasencia
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Adam R Abate
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, California Institute for Quantitative Biosciences, San Francisco, CA 94158, USA.,Chan Zuckerberg Biohub, San Francisco, CA, USA
| | - Douglas L Rosene
- Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, MA 02118, USA
| | - Kevin J Hodgetts
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Marco Prinz
- Institute of Neuropathology, University of Freiburg, D-79106 Freiburg, Germany.,Signaling Research Centres BIOSS and CIBSS, University of Freiburg, D-79106 Freiburg, Germany.,Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, D-79106 Freiburg, Germany
| | - Jack P Antel
- Neuroimmunology Unit, Montreal Neurological Institute, Department of Neurology and Neurosurgery, McGill University, Montreal, QC H3A 2B4, Canada
| | - Alexandre Prat
- Neuroimmunology Research Laboratory, Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, QC H2X 0A9, Canada
| | - Francisco J Quintana
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA. .,Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
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176
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Ziabska K, Ziemka-Nalecz M, Pawelec P, Sypecka J, Zalewska T. Aberrant Complement System Activation in Neurological Disorders. Int J Mol Sci 2021; 22:4675. [PMID: 33925147 PMCID: PMC8125564 DOI: 10.3390/ijms22094675] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 04/22/2021] [Accepted: 04/26/2021] [Indexed: 12/13/2022] Open
Abstract
The complement system is an assembly of proteins that collectively participate in the functions of the healthy and diseased brain. The complement system plays an important role in the maintenance of uninjured (healthy) brain homeostasis, contributing to the clearance of invading pathogens and apoptotic cells, and limiting the inflammatory immune response. However, overactivation or underregulation of the entire complement cascade within the brain may lead to neuronal damage and disturbances in brain function. During the last decade, there has been a growing interest in the role that this cascading pathway plays in the neuropathology of a diverse array of brain disorders (e.g., acute neurotraumatic insult, chronic neurodegenerative diseases, and psychiatric disturbances) in which interruption of neuronal homeostasis triggers complement activation. Dysfunction of the complement promotes a disease-specific response that may have either beneficial or detrimental effects. Despite recent advances, the explicit link between complement component regulation and brain disorders remains unclear. Therefore, a comprehensible understanding of such relationships at different stages of diseases could provide new insight into potential therapeutic targets to ameliorate or slow progression of currently intractable disorders in the nervous system. Hence, the aim of this review is to provide a summary of the literature on the emerging role of the complement system in certain brain disorders.
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Affiliation(s)
| | | | | | | | - Teresa Zalewska
- Mossakowski Medical Research Centre, NeuroRepair Department, Polish Academy of Sciences, 5 Pawinskiego Street, 02-106 Warsaw, Poland; (K.Z.); (M.Z.-N.); (P.P.); (J.S.)
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177
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Qiu WQ, Luo S, Ma SA, Saminathan P, Li H, Gunnersen JM, Gelbard HA, Hammond JW. The Sez6 Family Inhibits Complement by Facilitating Factor I Cleavage of C3b and Accelerating the Decay of C3 Convertases. Front Immunol 2021; 12:607641. [PMID: 33936031 PMCID: PMC8081827 DOI: 10.3389/fimmu.2021.607641] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 03/23/2021] [Indexed: 12/31/2022] Open
Abstract
The Sez6 family consists of Sez6, Sez6L, and Sez6L2. Its members are expressed throughout the brain and have been shown to influence synapse numbers and dendritic morphology. They are also linked to various neurological and psychiatric disorders. All Sez6 family members contain 2-3 CUB domains and 5 complement control protein (CCP) domains, suggesting that they may be involved in complement regulation. We show that Sez6 family members inhibit C3b/iC3b opsonization by the classical and alternative pathways with varying degrees of efficacy. For the classical pathway, Sez6 is a strong inhibitor, Sez6L2 is a moderate inhibitor, and Sez6L is a weak inhibitor. For the alternative pathway, the complement inhibitory activity of Sez6, Sez6L, and Sez6L2 all equaled or exceeded the activity of the known complement regulator MCP. Using Sez6L2 as the representative family member, we show that it specifically accelerates the dissociation of C3 convertases. Sez6L2 also functions as a cofactor for Factor I to facilitate the cleavage of C3b; however, Sez6L2 has no cofactor activity toward C4b. In summary, the Sez6 family are novel complement regulators that inhibit C3 convertases and promote C3b degradation.
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Affiliation(s)
- Wen Q Qiu
- Center for Neurotherapeutics Discovery, Department of Neurology, University of Rochester Medical Center, Rochester, NY, United States
| | - Shaopeiwen Luo
- Center for Neurotherapeutics Discovery, Department of Neurology, University of Rochester Medical Center, Rochester, NY, United States
| | - Stefanie A Ma
- Center for Neurotherapeutics Discovery, Department of Neurology, University of Rochester Medical Center, Rochester, NY, United States
| | - Priyanka Saminathan
- Center for Neurotherapeutics Discovery, Department of Neurology, University of Rochester Medical Center, Rochester, NY, United States
| | - Herman Li
- Center for Neurotherapeutics Discovery, Department of Neurology, University of Rochester Medical Center, Rochester, NY, United States
| | - Jenny M Gunnersen
- Department of Anatomy and Neuroscience and The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, VIC, Australia
| | - Harris A Gelbard
- Center for Neurotherapeutics Discovery, Department of Neurology, University of Rochester Medical Center, Rochester, NY, United States
| | - Jennetta W Hammond
- Center for Neurotherapeutics Discovery, Department of Neurology, University of Rochester Medical Center, Rochester, NY, United States
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178
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Garred P, Tenner AJ, Mollnes TE. Therapeutic Targeting of the Complement System: From Rare Diseases to Pandemics. Pharmacol Rev 2021; 73:792-827. [PMID: 33687995 PMCID: PMC7956994 DOI: 10.1124/pharmrev.120.000072] [Citation(s) in RCA: 83] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The complement system was discovered at the end of the 19th century as a heat-labile plasma component that "complemented" the antibodies in killing microbes, hence the name "complement." Complement is also part of the innate immune system, protecting the host by recognition of pathogen-associated molecular patterns. However, complement is multifunctional far beyond infectious defense. It contributes to organ development, such as sculpting neuron synapses, promoting tissue regeneration and repair, and rapidly engaging and synergizing with a number of processes, including hemostasis leading to thromboinflammation. Complement is a double-edged sword. Although it usually protects the host, it may cause tissue damage when dysregulated or overactivated, such as in the systemic inflammatory reaction seen in trauma and sepsis and severe coronavirus disease 2019 (COVID-19). Damage-associated molecular patterns generated during ischemia-reperfusion injuries (myocardial infarction, stroke, and transplant dysfunction) and in chronic neurologic and rheumatic disease activate complement, thereby increasing damaging inflammation. Despite the long list of diseases with potential for ameliorating complement modulation, only a few rare diseases are approved for clinical treatment targeting complement. Those currently being efficiently treated include paroxysmal nocturnal hemoglobinuria, atypical hemolytic-uremic syndrome, myasthenia gravis, and neuromyelitis optica spectrum disorders. Rare diseases, unfortunately, preclude robust clinical trials. The increasing evidence for complement as a pathogenetic driver in many more common diseases suggests an opportunity for future complement therapy, which, however, requires robust clinical trials; one ongoing example is COVID-19 disease. The current review aims to discuss complement in disease pathogenesis and discuss future pharmacological strategies to treat these diseases with complement-targeted therapies. SIGNIFICANCE STATEMENT: The complement system is the host's defense friend by protecting it from invading pathogens, promoting tissue repair, and maintaining homeostasis. Complement is a double-edged sword, since when dysregulated or overactivated it becomes the host's enemy, leading to tissue damage, organ failure, and, in worst case, death. A number of acute and chronic diseases are candidates for pharmacological treatment to avoid complement-dependent damage, ranging from the well established treatment for rare diseases to possible future treatment of large patient groups like the pandemic coronavirus disease 2019.
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Affiliation(s)
- Peter Garred
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Rigshospitalet, Copenhagen, Denmark, and Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark (P.G.); Departments of Molecular Biology and Biochemistry, Neurobiology and Behavior, and Pathology and Laboratory Medicine, University of California, Irvine, California (A.J.T.); and Research Laboratory, Nordland Hospital, Bodø, Norway, Faculty of Health Sciences, K.G. Jebsen TREC, University of Tromsø, Tromsø, Norway (T.E.M.); Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, Trondheim, Norway (T.E.M.); and Department of Immunology, Oslo University Hospital and University of Oslo, Oslo, Norway (T.E.M.)
| | - Andrea J Tenner
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Rigshospitalet, Copenhagen, Denmark, and Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark (P.G.); Departments of Molecular Biology and Biochemistry, Neurobiology and Behavior, and Pathology and Laboratory Medicine, University of California, Irvine, California (A.J.T.); and Research Laboratory, Nordland Hospital, Bodø, Norway, Faculty of Health Sciences, K.G. Jebsen TREC, University of Tromsø, Tromsø, Norway (T.E.M.); Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, Trondheim, Norway (T.E.M.); and Department of Immunology, Oslo University Hospital and University of Oslo, Oslo, Norway (T.E.M.)
| | - Tom E Mollnes
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Rigshospitalet, Copenhagen, Denmark, and Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark (P.G.); Departments of Molecular Biology and Biochemistry, Neurobiology and Behavior, and Pathology and Laboratory Medicine, University of California, Irvine, California (A.J.T.); and Research Laboratory, Nordland Hospital, Bodø, Norway, Faculty of Health Sciences, K.G. Jebsen TREC, University of Tromsø, Tromsø, Norway (T.E.M.); Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, Trondheim, Norway (T.E.M.); and Department of Immunology, Oslo University Hospital and University of Oslo, Oslo, Norway (T.E.M.)
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179
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Microglial Pruning: Relevance for Synaptic Dysfunction in Multiple Sclerosis and Related Experimental Models. Cells 2021; 10:cells10030686. [PMID: 33804596 PMCID: PMC8003660 DOI: 10.3390/cells10030686] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 03/12/2021] [Accepted: 03/17/2021] [Indexed: 12/11/2022] Open
Abstract
Microglia, besides being able to react rapidly to a wide range of environmental changes, are also involved in shaping neuronal wiring. Indeed, they actively participate in the modulation of neuronal function by regulating the elimination (or “pruning”) of weaker synapses in both physiologic and pathologic processes. Mounting evidence supports their crucial role in early synaptic loss, which is emerging as a hallmark of several neurodegenerative diseases, including multiple sclerosis (MS) and its preclinical models. MS is an inflammatory, immune-mediated pathology of the white matter in which demyelinating lesions may cause secondary neuronal death. Nevertheless, primitive grey matter (GM) damage is emerging as an important contributor to patients’ long-term disability, since it has been associated with early and progressive cognitive decline (CD), which seriously worsens the quality of life of MS patients. Widespread synapse loss even in the absence of demyelination, axon degeneration and neuronal death has been demonstrated in different GM structures, thus raising the possibility that synaptic dysfunction could be an early and possibly independent event in the neurodegenerative process associated with MS. This review provides an overview of microglial-dependent synapse elimination in the neuroinflammatory process that underlies MS and its experimental models.
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180
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Butler CA, Popescu AS, Kitchener EJA, Allendorf DH, Puigdellívol M, Brown GC. Microglial phagocytosis of neurons in neurodegeneration, and its regulation. J Neurochem 2021; 158:621-639. [PMID: 33608912 DOI: 10.1111/jnc.15327] [Citation(s) in RCA: 113] [Impact Index Per Article: 37.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 01/13/2021] [Accepted: 02/10/2021] [Indexed: 02/06/2023]
Abstract
There is growing evidence that excessive microglial phagocytosis of neurons and synapses contributes to multiple brain pathologies. RNA-seq and genome-wide association (GWAS) studies have linked multiple phagocytic genes to neurodegenerative diseases, and knock-out of phagocytic genes has been found to protect against neurodegeneration in animal models, suggesting that excessive microglial phagocytosis contributes to neurodegeneration. Here, we review recent evidence that microglial phagocytosis of live neurons and synapses causes neurodegeneration in animal models of Alzheimer's disease and other tauopathies, Parkinson's disease, frontotemporal dementias, multiple sclerosis, retinal degeneration and neurodegeneration induced by ischaemia, infection or ageing. We also review factors regulating microglial phagocytosis of neurons, including: nucleotides, frackalkine, phosphatidylserine, calreticulin, UDP, CD47, sialylation, complement, galectin-3, Apolipoprotein E, phagocytic receptors, Siglec receptors, cytokines, microglial epigenetics and expression profile. Some of these factors may be potential treatment targets to prevent neurodegeneration mediated by excessive microglial phagocytosis of live neurons and synapses.
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Affiliation(s)
- Claire A Butler
- Department of Biochemistry, University of Cambridge, Cambridge, UK
| | - Alma S Popescu
- Department of Biochemistry, University of Cambridge, Cambridge, UK
| | | | | | - Mar Puigdellívol
- Department of Biochemistry, University of Cambridge, Cambridge, UK.,Departament de Biomedicina, Facultat de Medicina, Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain
| | - Guy C Brown
- Department of Biochemistry, University of Cambridge, Cambridge, UK
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181
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Lim TKY, Ruthazer ES. Microglial trogocytosis and the complement system regulate axonal pruning in vivo. eLife 2021; 10:e62167. [PMID: 33724186 PMCID: PMC7963485 DOI: 10.7554/elife.62167] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Accepted: 02/28/2021] [Indexed: 12/14/2022] Open
Abstract
Partial phagocytosis-called trogocytosis-of axons by microglia has been documented in ex vivo preparations but has not been directly observed in vivo. The mechanisms that modulate microglial trogocytosis of axons and its function in neural circuit development remain poorly understood. Here, we directly observe axon trogocytosis by microglia in vivo in the developing Xenopus laevis retinotectal circuit. We show that microglia regulate pruning of retinal ganglion cell axons and are important for proper behavioral response to dark and bright looming stimuli. Using bioinformatics, we identify amphibian regulator of complement activation 3, a homolog of human CD46, as a neuronally expressed synapse-associated complement inhibitory molecule that inhibits trogocytosis and axonal pruning. Using a membrane-bound complement C3 fusion protein, we demonstrate that enhancing complement activity enhances axonal pruning. Our results support the model that microglia remodel axons via trogocytosis and that neurons can control this process through expression of complement inhibitory proteins.
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Affiliation(s)
- Tony KY Lim
- Department of Neurology & Neurosurgery, Montreal Neurological Institute-Hospital, McGill UniversityMontrealCanada
| | - Edward S Ruthazer
- Department of Neurology & Neurosurgery, Montreal Neurological Institute-Hospital, McGill UniversityMontrealCanada
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182
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Sokolova D, Childs T, Hong S. Insight into the role of phosphatidylserine in complement-mediated synapse loss in Alzheimer's disease. Fac Rev 2021; 10:19. [PMID: 33718936 PMCID: PMC7946395 DOI: 10.12703/r/10-19] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The innate immune system plays an integral role in the brain. Synaptic pruning, a fundamental process in developmental circuit refinement, is partially mediated by neuroimmune signalling at the synapse. In particular, microglia, the major tissue-resident macrophages of the brain, and the classical complement cascade, an innate immune pathway that aids in the clearance of unwanted material, have been implicated in mediating synapse elimination. Emerging data suggest that improper signalling of the innate immune pathway at the synapse leads to pathological synapse loss in age-related neurodegenerative diseases, including Alzheimer's disease. Now the key questions are whether synapses are targeted by complement and, if so, which synapses are vulnerable to elimination. Here, we review recent work implicating C1q, the initiator of the classical complement cascade, and surrounding glia as mediators of synapse loss. We examine how synapses could undergo apoptosis-like pathways in the Alzheimer brain, which may lead to the externalisation of phosphatidylserine on synapses. Finally, we discuss potential roles for microglia and astrocytes in this 'synaptic apoptosis'. Critical insight into neuroimmune regulatory pathways on synapses will be key to developing effective targets against pathological synapse loss in dementia.
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Affiliation(s)
- Dimitra Sokolova
- UK Dementia Research Institute, Institute of Neurology, University College London, Gower Street, London WC1E 6BT, UK
| | - Thomas Childs
- UK Dementia Research Institute, Institute of Neurology, University College London, Gower Street, London WC1E 6BT, UK
| | - Soyon Hong
- UK Dementia Research Institute, Institute of Neurology, University College London, Gower Street, London WC1E 6BT, UK
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183
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Lacagnina MJ, Heijnen CJ, Watkins LR, Grace PM. Autoimmune regulation of chronic pain. Pain Rep 2021; 6:e905. [PMID: 33981931 PMCID: PMC8108590 DOI: 10.1097/pr9.0000000000000905] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 11/19/2020] [Accepted: 01/19/2021] [Indexed: 01/24/2023] Open
Abstract
Chronic pain is an unpleasant and debilitating condition that is often poorly managed by existing therapeutics. Reciprocal interactions between the nervous system and the immune system have been recognized as playing an essential role in the initiation and maintenance of pain. In this review, we discuss how neuroimmune signaling can contribute to peripheral and central sensitization and promote chronic pain through various autoimmune mechanisms. These pathogenic autoimmune mechanisms involve the production and release of autoreactive antibodies from B cells. Autoantibodies-ie, antibodies that recognize self-antigens-have been identified as potential molecules that can modulate the function of nociceptive neurons and thereby induce persistent pain. Autoantibodies can influence neuronal excitability by activating the complement pathway; by directly signaling at sensory neurons expressing Fc gamma receptors, the receptors for the Fc fragment of immunoglobulin G immune complexes; or by binding and disrupting ion channels expressed by nociceptors. Using examples primarily from rheumatoid arthritis, complex regional pain syndrome, and channelopathies from potassium channel complex autoimmunity, we suggest that autoantibody signaling at the central nervous system has therapeutic implications for designing novel disease-modifying treatments for chronic pain.
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Affiliation(s)
- Michael J. Lacagnina
- Laboratories of Neuroimmunology, Department of Symptom Research, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Cobi J. Heijnen
- Laboratories of Neuroimmunology, Department of Symptom Research, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Linda R. Watkins
- Department of Psychology and Neuroscience, Center for Neuroscience, University of Colorado, Boulder, CO, USA
| | - Peter M. Grace
- Laboratories of Neuroimmunology, Department of Symptom Research, University of Texas MD Anderson Cancer Center, Houston, TX, USA
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184
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Duncan GJ, Simkins TJ, Emery B. Neuron-Oligodendrocyte Interactions in the Structure and Integrity of Axons. Front Cell Dev Biol 2021; 9:653101. [PMID: 33763430 PMCID: PMC7982542 DOI: 10.3389/fcell.2021.653101] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 02/15/2021] [Indexed: 12/12/2022] Open
Abstract
The myelination of axons by oligodendrocytes is a highly complex cell-to-cell interaction. Oligodendrocytes and axons have a reciprocal signaling relationship in which oligodendrocytes receive cues from axons that direct their myelination, and oligodendrocytes subsequently shape axonal structure and conduction. Oligodendrocytes are necessary for the maturation of excitatory domains on the axon including nodes of Ranvier, help buffer potassium, and support neuronal energy metabolism. Disruption of the oligodendrocyte-axon unit in traumatic injuries, Alzheimer's disease and demyelinating diseases such as multiple sclerosis results in axonal dysfunction and can culminate in neurodegeneration. In this review, we discuss the mechanisms by which demyelination and loss of oligodendrocytes compromise axons. We highlight the intra-axonal cascades initiated by demyelination that can result in irreversible axonal damage. Both the restoration of oligodendrocyte myelination or neuroprotective therapies targeting these intra-axonal cascades are likely to have therapeutic potential in disorders in which oligodendrocyte support of axons is disrupted.
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Affiliation(s)
- Greg J Duncan
- Jungers Center for Neurosciences Research, Department of Neurology, Oregon Health & Science University, Portland, OR, United States
| | - Tyrell J Simkins
- Jungers Center for Neurosciences Research, Department of Neurology, Oregon Health & Science University, Portland, OR, United States.,Vollum Institute, Oregon Health & Science University, Portland, OR, United States.,Department of Neurology, VA Portland Health Care System, Portland, OR, United States
| | - Ben Emery
- Jungers Center for Neurosciences Research, Department of Neurology, Oregon Health & Science University, Portland, OR, United States
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185
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Andoh M, Koyama R. Microglia regulate synaptic development and plasticity. Dev Neurobiol 2021; 81:568-590. [PMID: 33583110 PMCID: PMC8451802 DOI: 10.1002/dneu.22814] [Citation(s) in RCA: 58] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 01/13/2021] [Accepted: 02/09/2021] [Indexed: 12/12/2022]
Abstract
Synapses are fundamental structures of neural circuits that transmit information between neurons. Thus, the process of neural circuit formation via proper synaptic connections shapes the basis of brain functions and animal behavior. Synapses continuously undergo repeated formation and elimination throughout the lifetime of an organism, reflecting the dynamics of neural circuit function. The structural transformation of synapses has been described mainly in relation to neural activity-dependent strengthening and weakening of synaptic functions, that is, functional plasticity of synapses. An increasing number of studies have unveiled the roles of microglia, brain-resident immune cells that survey the brain parenchyma with highly motile processes, in synapse formation and elimination as well as in regulating synaptic function. Over the past 15 years, the molecular mechanisms underlying microglia-dependent regulation of synaptic plasticity have been thoroughly studied, and researchers have reported that the disruption of microglia-dependent regulation causes synaptic dysfunction that leads to brain diseases. In this review, we will broadly introduce studies that report the roles of microglia in synaptic plasticity and the possible underlying molecular mechanisms.
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Affiliation(s)
- Megumi Andoh
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Ryuta Koyama
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
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186
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Wang K, Li J, Zhang Y, Huang Y, Chen D, Shi Z, Smith AD, Li W, Gao Y. Central nervous system diseases related to pathological microglial phagocytosis. CNS Neurosci Ther 2021; 27:528-539. [PMID: 33650762 PMCID: PMC8025646 DOI: 10.1111/cns.13619] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 01/20/2021] [Accepted: 01/27/2021] [Indexed: 12/18/2022] Open
Abstract
Microglia are important phagocytes of the central nervous system (CNS). They play an important role in protecting the CNS by clearing necrotic tissue and apoptotic cells in many CNS diseases. However, recent studies have found that microglia can phagocytose parts of neurons excessively, such as the neuronal cell body, synapse, or myelin sheaths, before or after the onset of CNS diseases, leading to aggravated injury and impaired tissue repair. Meanwhile, reduced phagocytosis of synapses and myelin results in abnormal circuit connections and inhibition of remyelination, respectively. Previous studies focused primarily on the positive effects of microglia phagocytosis, whereas only a few studies have focused on the negative effects. In this review, we use the term "pathological microglial phagocytosis" to refer to excessive or reduced phagocytosis by microglia that leads to structural or functional abnormalities in target cells and brain tissue. The classification of pathological microglial phagocytosis, the composition, and activation of related signaling pathways, as well as the process of pathological phagocytosis in various kinds of CNS diseases, are described in this review. We hypothesize that pathological microglial phagocytosis leads to aggravation of tissue damage and negative functional outcome. For example, excessive microglial phagocytosis of synapses can be observed in Alzheimer's disease and schizophrenia, leading to significant synapse loss and memory impairment. In Parkinson's disease, ischemic stroke, and traumatic brain injury, excessive microglial phagocytosis of neuronal cell bodies causes impaired gray matter recovery and sensory dysfunction. We therefore believe that more studies should focus on the mechanism of pathological microglial phagocytosis and activation to uncover potential targets of therapeutic intervention.
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Affiliation(s)
- Ke Wang
- State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Jiaying Li
- State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Yue Zhang
- State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Yichen Huang
- State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Di Chen
- State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Ziyu Shi
- State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Amanda D Smith
- Geriatric Research, Education and Clinical Center, Veterans Affairs Pittsburgh Health Care System, Pittsburgh, PA, USA
| | - Wei Li
- State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Yanqin Gao
- State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, China
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187
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Baltan S, Jawaid SS, Chomyk AM, Kidd GJ, Chen J, Battapady HD, Chan R, Dutta R, Trapp BD. Neuronal hibernation following hippocampal demyelination. Acta Neuropathol Commun 2021; 9:34. [PMID: 33648591 PMCID: PMC7923530 DOI: 10.1186/s40478-021-01130-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 02/11/2021] [Indexed: 12/15/2022] Open
Abstract
Cognitive dysfunction occurs in greater than 50% of individuals with multiple sclerosis (MS). Hippocampal demyelination is a prominent feature of postmortem MS brains and hippocampal atrophy correlates with cognitive decline in MS patients. Cellular and molecular mechanisms responsible for neuronal dysfunction in demyelinated hippocampi are not fully understood. Here we investigate a mouse model of hippocampal demyelination where twelve weeks of treatment with the oligodendrocyte toxin, cuprizone, demyelinates over 90% of the hippocampus and causes decreased memory/learning. Long-term potentiation (LTP) of hippocampal CA1 pyramidal neurons is considered to be a major cellular readout of learning and memory in the mammalian brain. In acute slices, we establish that hippocampal demyelination abolishes LTP and excitatory post-synaptic potentials of CA1 neurons, while pre-synaptic function of Schaeffer collateral fibers is preserved. Demyelination also reduced Ca2+-mediated firing of hippocampal neurons in vivo. Using three-dimensional electron microscopy, we investigated the number, shape (mushroom, stubby, thin), and post-synaptic densities (PSDs) of dendritic spines that facilitate LTP. Hippocampal demyelination did not alter the number of dendritic spines. Surprisingly, dendritic spines appeared to be more mature in demyelinated hippocampi, with a significant increase in mushroom-shaped spines, more perforated PSDs, and more astrocyte participation in the tripartite synapse. RNA sequencing experiments identified 400 altered transcripts in demyelinated hippocampi. Gene transcripts that regulate myelination, synaptic signaling, astrocyte function, and innate immunity were altered in demyelinated hippocampi. Hippocampal remyelination rescued synaptic transmission, LTP, and the majority of gene transcript changes. We establish that CA1 neurons projecting demyelinated axons silence their dendritic spines and hibernate in a state that may protect the demyelinated axon and facilitates functional recovery following remyelination.
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Affiliation(s)
- Selva Baltan
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue/NC30, Cleveland, OH, 44195, USA
- Department of Perioperative Medicine, Oregon Health and Science University, Portland, OR, 97239, USA
| | - Safdar S Jawaid
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue/NC30, Cleveland, OH, 44195, USA
- Department of Pediatrics, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA
- Department of Biomedical Engineering, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Anthony M Chomyk
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue/NC30, Cleveland, OH, 44195, USA
| | - Grahame J Kidd
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue/NC30, Cleveland, OH, 44195, USA
| | - Jacqueline Chen
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue/NC30, Cleveland, OH, 44195, USA
- Imaging Institute, Cleveland Clinic, Cleveland, OH, 44195, USA
| | - Harsha D Battapady
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue/NC30, Cleveland, OH, 44195, USA
| | - Ricky Chan
- Cleveland Institute for Computational Biology, Cleveland, OH, 44106, USA
| | - Ranjan Dutta
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue/NC30, Cleveland, OH, 44195, USA
| | - Bruce D Trapp
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue/NC30, Cleveland, OH, 44195, USA.
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188
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Zoupi L, Booker SA, Eigel D, Werner C, Kind PC, Spires-Jones TL, Newland B, Williams AC. Selective vulnerability of inhibitory networks in multiple sclerosis. Acta Neuropathol 2021; 141:415-429. [PMID: 33449171 PMCID: PMC7882577 DOI: 10.1007/s00401-020-02258-z] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 12/21/2020] [Accepted: 12/22/2020] [Indexed: 01/01/2023]
Abstract
In multiple sclerosis (MS), a chronic demyelinating disease of the central nervous system, neurodegeneration is detected early in the disease course and is associated with the long-term disability of patients. Neurodegeneration is linked to both inflammation and demyelination, but its exact cause remains unknown. This gap in knowledge contributes to the current lack of treatments for the neurodegenerative phase of MS. Here we ask if neurodegeneration in MS affects specific neuronal components and if it is the result of demyelination. Neuropathological examination of secondary progressive MS motor cortices revealed a selective vulnerability of inhibitory interneurons in MS. The generation of a rodent model of focal subpial cortical demyelination reproduces this selective neurodegeneration providing a new preclinical model for the study of neuroprotective treatments.
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Affiliation(s)
- Lida Zoupi
- Centre for Regenerative Medicine, Institute for Regeneration and Repair, University of Edinburgh, Edinburgh, EH16 4UU, UK
| | - Sam A Booker
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, EH8 9XD, UK
- Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, EH8 9XD, UK
- Patrick Wild Centre for Autism Research, University of Edinburgh, Edinburgh, EH8 9XD, UK
| | - Dimitri Eigel
- Leibniz-Institut Für Polymerforschung Dresden E.V, Max Bergmann Center of Biomaterials Dresden, Hohe Straße 6, 01069, Dresden, Germany
| | - Carsten Werner
- Leibniz-Institut Für Polymerforschung Dresden E.V, Max Bergmann Center of Biomaterials Dresden, Hohe Straße 6, 01069, Dresden, Germany
| | - Peter C Kind
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, EH8 9XD, UK
- Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, EH8 9XD, UK
- Patrick Wild Centre for Autism Research, University of Edinburgh, Edinburgh, EH8 9XD, UK
| | - Tara L Spires-Jones
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, EH8 9XD, UK
- UK Dementia Research Institute, University of Edinburgh, Edinburgh, EH8 9JZ, UK
| | - Ben Newland
- Leibniz-Institut Für Polymerforschung Dresden E.V, Max Bergmann Center of Biomaterials Dresden, Hohe Straße 6, 01069, Dresden, Germany
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, CF10 3NB, UK
| | - Anna C Williams
- Centre for Regenerative Medicine, Institute for Regeneration and Repair, University of Edinburgh, Edinburgh, EH16 4UU, UK.
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189
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Schirmer L, Schafer DP, Bartels T, Rowitch DH, Calabresi PA. Diversity and Function of Glial Cell Types in Multiple Sclerosis. Trends Immunol 2021; 42:228-247. [PMID: 33593693 PMCID: PMC7914214 DOI: 10.1016/j.it.2021.01.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 01/04/2021] [Accepted: 01/07/2021] [Indexed: 12/25/2022]
Abstract
Glial subtype diversity is an emerging topic in neurobiology and immune-mediated neurological diseases such as multiple sclerosis (MS). We discuss recent conceptual and technological advances that allow a better understanding of the transcriptomic and functional heterogeneity of oligodendrocytes (OLs), astrocytes, and microglial cells under inflammatory-demyelinating conditions. Recent single cell transcriptomic studies suggest the occurrence of novel homeostatic and reactive glial subtypes and provide insight into the molecular events during disease progression. Multiplexed RNA in situ hybridization has enabled 'mapping back' dysregulated gene expression to glial subtypes within the MS lesion microenvironment. These findings suggest novel homeostatic and reactive glial-cell-type functions both in immune-related processes and neuroprotection relevant to understanding the pathology of MS.
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Affiliation(s)
- Lucas Schirmer
- Department of Neurology, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany; Center for Translational Neuroscience and Institute for Innate Immunoscience, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany; Interdisciplinary Center for Neurosciences, Heidelberg University, Heidelberg, Germany.
| | - Dorothy P Schafer
- Department of Neurobiology and the Brudnik Neuropsychiatric Institute, University of Massachusetts Medical School, Worcester, MA, USA
| | - Theresa Bartels
- Department of Paediatrics, Wellcome - MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK
| | - David H Rowitch
- Department of Paediatrics, Wellcome - MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK; Departments of Pediatrics and Neurosurgery, Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California San Francisco, San Francisco, CA, USA
| | - Peter A Calabresi
- Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD, USA; Solomon H. Snyder Department of Neuroscience, Johns Hopkins School of Medicine, Baltimore, MD, USA.
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190
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Keller CW, Oechtering J, Wiendl H, Kappos L, Kuhle J, Lünemann JD. Impact of complement activation on clinical outcomes in multiple sclerosis. Ann Clin Transl Neurol 2021; 8:944-950. [PMID: 33646629 PMCID: PMC8045986 DOI: 10.1002/acn3.51334] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 02/04/2021] [Accepted: 02/14/2021] [Indexed: 11/08/2022] Open
Abstract
We determined activation profiles of the classical and alternative complement pathway in 39 treatment‐naïve patients with early relapse‐onset MS. Plasma concentrations of complement fragments were unchanged in MS compared to 32 patients with non‐inflammatory neurological diseases. Profiles in patients experiencing clinical exacerbations did not differ from patients with stable disease and did not correlate with baseline EDSS, numbers of T2 lesions and time to second relapse. Long‐term EDSS outcomes 4 years after diagnosis did not significantly correlate with baseline complement levels. These data do not support the use of complement activation products as biomarkers for disease activity in early MS.
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Affiliation(s)
- Christian W Keller
- Department of Neurology with Institute of Translational Neurology, University Hospital Münster, Münster, 48149, Germany
| | - Johanna Oechtering
- Neurologic Clinic and Policlinic, Research Center for Clinical Neuroimmunology and Neuroscience Basel, University Hospital Basel, University of Basel, Basel, Switzerland
| | - Heinz Wiendl
- Department of Neurology with Institute of Translational Neurology, University Hospital Münster, Münster, 48149, Germany
| | - Ludwig Kappos
- Neurologic Clinic and Policlinic, Research Center for Clinical Neuroimmunology and Neuroscience Basel, University Hospital Basel, University of Basel, Basel, Switzerland
| | - Jens Kuhle
- Neurologic Clinic and Policlinic, Research Center for Clinical Neuroimmunology and Neuroscience Basel, University Hospital Basel, University of Basel, Basel, Switzerland
| | - Jan D Lünemann
- Department of Neurology with Institute of Translational Neurology, University Hospital Münster, Münster, 48149, Germany
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191
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Jafari M, Schumacher AM, Snaidero N, Ullrich Gavilanes EM, Neziraj T, Kocsis-Jutka V, Engels D, Jürgens T, Wagner I, Weidinger JDF, Schmidt SS, Beltrán E, Hagan N, Woodworth L, Ofengeim D, Gans J, Wolf F, Kreutzfeldt M, Portugues R, Merkler D, Misgeld T, Kerschensteiner M. Phagocyte-mediated synapse removal in cortical neuroinflammation is promoted by local calcium accumulation. Nat Neurosci 2021; 24:355-367. [PMID: 33495636 DOI: 10.1038/s41593-020-00780-7] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 12/16/2020] [Indexed: 01/30/2023]
Abstract
Cortical pathology contributes to chronic cognitive impairment of patients suffering from the neuroinflammatory disease multiple sclerosis (MS). How such gray matter inflammation affects neuronal structure and function is not well understood. In the present study, we use functional and structural in vivo imaging in a mouse model of cortical MS to demonstrate that bouts of cortical inflammation disrupt cortical circuit activity coincident with a widespread, but transient, loss of dendritic spines. Spines destined for removal show local calcium accumulations and are subsequently removed by invading macrophages or activated microglia. Targeting phagocyte activation with a new antagonist of the colony-stimulating factor 1 receptor prevents cortical synapse loss. Overall, our study identifies synapse loss as a key pathological feature of inflammatory gray matter lesions that is amenable to immunomodulatory therapy.
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Affiliation(s)
- Mehrnoosh Jafari
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians University Munich, Munich, Germany.,Biomedical Center, Faculty of Medicine, Ludwig-Maximilians University Munich, Munich, Germany
| | - Adrian-Minh Schumacher
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians University Munich, Munich, Germany.,Biomedical Center, Faculty of Medicine, Ludwig-Maximilians University Munich, Munich, Germany
| | - Nicolas Snaidero
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians University Munich, Munich, Germany.,Institute of Neuronal Cell Biology, Technical University of Munich, Munich, Germany.,German Center for Neurodegenerative Diseases, Munich, Germany
| | - Emily M Ullrich Gavilanes
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians University Munich, Munich, Germany.,Biomedical Center, Faculty of Medicine, Ludwig-Maximilians University Munich, Munich, Germany
| | - Tradite Neziraj
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians University Munich, Munich, Germany.,Biomedical Center, Faculty of Medicine, Ludwig-Maximilians University Munich, Munich, Germany
| | - Virág Kocsis-Jutka
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians University Munich, Munich, Germany.,Biomedical Center, Faculty of Medicine, Ludwig-Maximilians University Munich, Munich, Germany
| | - Daniel Engels
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians University Munich, Munich, Germany.,Biomedical Center, Faculty of Medicine, Ludwig-Maximilians University Munich, Munich, Germany
| | - Tanja Jürgens
- Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland
| | - Ingrid Wagner
- Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland
| | - Juan Daniel Flórez Weidinger
- Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany.,Bernstein Center for Computational Neuroscience, University of Göttingen, Göttingen, Germany.,Max Planck Institute for Experimental Medicine, Göttingen, Germany.,Center for Biostructural Imaging of Neurodegeneration, Göttingen, Germany
| | - Stephanie S Schmidt
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians University Munich, Munich, Germany
| | - Eduardo Beltrán
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians University Munich, Munich, Germany.,Biomedical Center, Faculty of Medicine, Ludwig-Maximilians University Munich, Munich, Germany
| | - Nellwyn Hagan
- Rare and Neurological Disease Research, Sanofi, Framingham, MA, USA
| | - Lisa Woodworth
- Rare and Neurological Disease Research, Sanofi, Framingham, MA, USA
| | - Dimitry Ofengeim
- Rare and Neurological Disease Research, Sanofi, Framingham, MA, USA
| | - Joseph Gans
- Translational Sciences Genomics, Sanofi, Framingham, MA, USA
| | - Fred Wolf
- Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany.,Bernstein Center for Computational Neuroscience, University of Göttingen, Göttingen, Germany.,Max Planck Institute for Experimental Medicine, Göttingen, Germany.,Center for Biostructural Imaging of Neurodegeneration, Göttingen, Germany.,Campus Institute for Dynamics of Biological Networks, University of Göttingen, Göttingen, Germany
| | - Mario Kreutzfeldt
- Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland.,Division of Clinical Pathology, Geneva University Hospital, Geneva, Switzerland
| | - Ruben Portugues
- Sensorimotor Control, Max Planck Institute of Neurobiology, Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Doron Merkler
- Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland. .,Division of Clinical Pathology, Geneva University Hospital, Geneva, Switzerland.
| | - Thomas Misgeld
- Institute of Neuronal Cell Biology, Technical University of Munich, Munich, Germany. .,German Center for Neurodegenerative Diseases, Munich, Germany. .,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.
| | - Martin Kerschensteiner
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians University Munich, Munich, Germany. .,Biomedical Center, Faculty of Medicine, Ludwig-Maximilians University Munich, Munich, Germany. .,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.
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192
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Sekyi MT, Lauderdale K, Atkinson KC, Golestany B, Karim H, Feri M, Soto JS, Diaz C, Kim SH, Cilluffo M, Nusinowitz S, Katzenellenbogen JA, Tiwari‐Woodruff SK. Alleviation of extensive visual pathway dysfunction by a remyelinating drug in a chronic mouse model of multiple sclerosis. Brain Pathol 2021; 31:312-332. [PMID: 33368801 PMCID: PMC8018057 DOI: 10.1111/bpa.12930] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 12/09/2020] [Accepted: 12/11/2020] [Indexed: 11/30/2022] Open
Abstract
Visual deficits are among the most prevalent symptoms in patients with multiple sclerosis (MS). To understand deficits in the visual pathway during MS and potential treatment effects, we used experimental autoimmune encephalomyelitis (EAE), the most commonly used animal model of MS. The afferent visual pathway was assessed in vivo using optical coherence tomography (OCT), electroretinography (ERG), and visually evoked cortical potentials (VEPs). Inflammation, demyelination, and neurodegeneration were examined by immunohistochemistry ex vivo. In addition, an immunomodulatory, remyelinating agent, the estrogen receptor β ligand chloroindazole (IndCl), was tested for its therapeutic potential in the visual pathway. EAE produced functional deficits in visual system electrophysiology, including suppression of ERG and VEP waveform amplitudes and increased signal latencies. Therapeutic IndCl rescued overall visual system latency by VEP but had little impact on amplitude or ERG findings relative to vehicle. Faster VEP conduction in IndCl-treated mice was associated with enhanced myelin basic protein signal in all visual system structures examined. IndCl preserved retinal ganglion cells (RGCs) and oligodendrocyte density in the prechiasmatic white matter, but similar retinal nerve fiber layer thinning by OCT was noted in vehicle and IndCl-treated mice. Although IndCl differentially attenuated leukocyte and astrocyte staining signal throughout the structures analyzed, axolemmal varicosities were observed in all visual fiber tracts of mice with EAE irrespective of treatment, suggesting impaired axonal energy homeostasis. These data support incomplete functional recovery of VEP amplitude with IndCl, as fiber tracts displayed persistent axon pathology despite remyelination-induced decreases in latencies, evidenced by reduced optic nerve g-ratio in IndCl-treated mice. Although additional studies are required, these findings demonstrate the dynamics of visual pathway dysfunction and disability during EAE, along with the importance of early treatment to mitigate EAE-induced axon damage.
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Affiliation(s)
- Maria T. Sekyi
- Division of Biomedical SciencesRiverside School of MedicineUniversity of CaliforniaRiversideCAUSA
- Department of BioengineeringRiverside Bourns School of EngineeringUniversity of CaliforniaRiversideCAUSA
| | - Kelli Lauderdale
- Division of Biomedical SciencesRiverside School of MedicineUniversity of CaliforniaRiversideCAUSA
| | - Kelley C. Atkinson
- Division of Biomedical SciencesRiverside School of MedicineUniversity of CaliforniaRiversideCAUSA
| | - Batis Golestany
- Division of Biomedical SciencesRiverside School of MedicineUniversity of CaliforniaRiversideCAUSA
| | - Hawra Karim
- Division of Biomedical SciencesRiverside School of MedicineUniversity of CaliforniaRiversideCAUSA
| | - Micah Feri
- Division of Biomedical SciencesRiverside School of MedicineUniversity of CaliforniaRiversideCAUSA
| | - Joselyn S. Soto
- Division of Biomedical SciencesRiverside School of MedicineUniversity of CaliforniaRiversideCAUSA
| | - Cobi Diaz
- Division of Biomedical SciencesRiverside School of MedicineUniversity of CaliforniaRiversideCAUSA
| | - Sung Hoon Kim
- Department of Chemistry and Cancer CenterUniversity of Illinois at Urbana‐ChampaignUrbanaILUSA
| | - Marianne Cilluffo
- BRI Electron Microscopy LaboratoryLos Angeles School of MedicineUniversity of CaliforniaLos AngelesCAUSA
| | - Steven Nusinowitz
- Stein Eye InstituteLos Angeles School of MedicineUniversity of CaliforniaLos AngelesCAUSA
| | | | - Seema K. Tiwari‐Woodruff
- Division of Biomedical SciencesRiverside School of MedicineUniversity of CaliforniaRiversideCAUSA
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193
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Chen T, Bosco DB, Ying Y, Tian DS, Wu LJ. The Emerging Role of Microglia in Neuromyelitis Optica. Front Immunol 2021; 12:616301. [PMID: 33679755 PMCID: PMC7933531 DOI: 10.3389/fimmu.2021.616301] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Accepted: 01/04/2021] [Indexed: 12/13/2022] Open
Abstract
Neuromyelitis optica (NMO) is an autoantibody-triggered neuro-inflammatory disease which preferentially attacks the spinal cord and optic nerve. Its defining autoantibody is specific for the water channel protein, aquaporin-4 (AQP4), which primarily is localized at the end-feet of astrocytes. Histopathology studies of early NMO lesions demonstrated prominent activation of microglia, the resident immune sentinels of the central nervous system (CNS). Significant microglial reactivity is also observed in NMO animal models induced by introducing AQP4-IgG into the CNS. Here we review the potential roles for microglial activation in human NMO patients as well as different animal models of NMO. We will focus primarily on the molecular mechanisms underlying microglial function and microglia-astrocyte interaction in NMO pathogenesis. Understanding the role of microglia in NMO pathology may yield novel therapeutic approaches for this disease.
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Affiliation(s)
- Tingjun Chen
- Department of Neurology, Mayo Clinic, Rochester, MN, United States
| | - Dale B. Bosco
- Department of Neurology, Mayo Clinic, Rochester, MN, United States
| | - Yanlu Ying
- Department of Neurology, Mayo Clinic, Rochester, MN, United States
| | - Dai-Shi Tian
- Department of Neurology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Long-Jun Wu
- Department of Neurology, Mayo Clinic, Rochester, MN, United States
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, United States
- Department of Immunology, Mayo Clinic, Rochester, MN, United States
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194
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Yadav SK, Ito N, Soin D, Ito K, Dhib-Jalbut S. Dimethyl Fumarate Suppresses Demyelination and Axonal Loss through Reduction in Pro-Inflammatory Macrophage-Induced Reactive Astrocytes and Complement C3 Deposition. J Clin Med 2021; 10:jcm10040857. [PMID: 33669652 PMCID: PMC7922578 DOI: 10.3390/jcm10040857] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 02/06/2021] [Accepted: 02/14/2021] [Indexed: 01/24/2023] Open
Abstract
Dimethyl fumarate (DMF) is an oral agent for relapsing-remitting multiple sclerosis (RRMS). In this study, we investigated the therapeutic mechanism of DMF using experimental autoimmune encephalomyelitis (EAE). DMF treatment decreased the proliferation of T cells and the production of IL-17A and GM-CSF. DMF treatment also decreased the development and/or infiltration of macrophages in the central nervous system (CNS), and reduced the ratio of iNOS+ pro-inflammatory macrophage versus Ym1+ immunomodulatory macrophages. Furthermore, DMF treatment suppressed the deposition of complement C3 (C3) and development of reactive C3+ astrocytes. The decrease in iNOS+ macrophages, C3+astrocytes, and C3 deposition in the CNS resulted in the reduction in demyelination and axonal loss. This study suggests that the beneficial effects of DMF involve the suppression of iNOS+ pro-inflammatory macrophages, C3+ astrocytes, and deposition of C3 in the CNS.
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Affiliation(s)
- Sudhir K. Yadav
- Department of Neurology, Rutgers-Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA; (S.K.Y.); (N.I.); (D.S.)
| | - Naoko Ito
- Department of Neurology, Rutgers-Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA; (S.K.Y.); (N.I.); (D.S.)
| | - Devika Soin
- Department of Neurology, Rutgers-Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA; (S.K.Y.); (N.I.); (D.S.)
- Touro College of Osteopathic Medicine, Middletown, NY 10940, USA
| | - Kouichi Ito
- Department of Neurology, Rutgers-Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA; (S.K.Y.); (N.I.); (D.S.)
- Correspondence: (K.I.); (S.D.-J.); Tel.: +1-732-235-5482 (K.I.); +1-732-235-7335 (S.D.-J.)
| | - Suhayl Dhib-Jalbut
- Department of Neurology, Rutgers-Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA; (S.K.Y.); (N.I.); (D.S.)
- Department of Neurology, New Jersey Medical School, Newark, NJ 07101, USA
- Correspondence: (K.I.); (S.D.-J.); Tel.: +1-732-235-5482 (K.I.); +1-732-235-7335 (S.D.-J.)
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195
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Zarantonello A, Pedersen H, Laursen NS, Andersen GR. Nanobodies Provide Insight into the Molecular Mechanisms of the Complement Cascade and Offer New Therapeutic Strategies. Biomolecules 2021; 11:biom11020298. [PMID: 33671302 PMCID: PMC7922070 DOI: 10.3390/biom11020298] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 02/10/2021] [Accepted: 02/11/2021] [Indexed: 01/22/2023] Open
Abstract
The complement system is part of the innate immune response, where it provides immediate protection from infectious agents and plays a fundamental role in homeostasis. Complement dysregulation occurs in several diseases, where the tightly regulated proteolytic cascade turns offensive. Prominent examples are atypical hemolytic uremic syndrome, paroxysmal nocturnal hemoglobinuria and Alzheimer’s disease. Therapeutic intervention targeting complement activation may allow treatment of such debilitating diseases. In this review, we describe a panel of complement targeting nanobodies that allow modulation at different steps of the proteolytic cascade, from the activation of the C1 complex in the classical pathway to formation of the C5 convertase in the terminal pathway. Thorough structural and functional characterization has provided a deep mechanistic understanding of the mode of inhibition for each of the nanobodies. These complement specific nanobodies are novel powerful probes for basic research and offer new opportunities for in vivo complement modulation.
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Affiliation(s)
- Alessandra Zarantonello
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus, Denmark; (A.Z.); (H.P.)
| | - Henrik Pedersen
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus, Denmark; (A.Z.); (H.P.)
| | - Nick S. Laursen
- Department of Biomedicine, Aarhus University, 8000 Aarhus, Denmark;
| | - Gregers R. Andersen
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus, Denmark; (A.Z.); (H.P.)
- Correspondence: ; Tel.: +45-30256646
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196
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Nevoux J, Alexandru M, Bellocq T, Tanaka L, Hayashi Y, Watabe T, Lahlou H, Tani K, Edge ASB. An antibody to RGMa promotes regeneration of cochlear synapses after noise exposure. Sci Rep 2021; 11:2937. [PMID: 33536466 PMCID: PMC7859405 DOI: 10.1038/s41598-021-81294-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 01/05/2021] [Indexed: 11/09/2022] Open
Abstract
Auditory neuropathy is caused by the loss of afferent input to the brainstem via the components of the neural pathway comprising inner hair cells and the first order neurons of the spiral ganglion. Recent work has identified the synapse between cochlear primary afferent neurons and sensory hair cells as a particularly vulnerable component of this pathway. Loss of these synapses due to noise exposure or aging results in the pathology identified as hidden hearing loss, an initial stage of cochlear dysfunction that goes undetected in standard hearing tests. We show here that repulsive axonal guidance molecule a (RGMa) acts to prevent regrowth and synaptogenesis of peripheral auditory nerve fibers with inner hair cells. Treatment of noise-exposed animals with an anti-RGMa blocking antibody regenerated inner hair cell synapses and resulted in recovery of wave-I amplitude of the auditory brainstem response, indicating effective reversal of synaptopathy.
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Affiliation(s)
- Jerome Nevoux
- Department of Otololaryngology, Harvard Medical School, Boston, MA, 02115, USA.,Eaton-Peabody Laboratories, Massachusetts Eye and Ear, 243 Charles St., Boston, MA, 02114, USA
| | - Mihaela Alexandru
- Department of Otololaryngology, Harvard Medical School, Boston, MA, 02115, USA.,Eaton-Peabody Laboratories, Massachusetts Eye and Ear, 243 Charles St., Boston, MA, 02114, USA
| | - Thomas Bellocq
- Department of Otololaryngology, Harvard Medical School, Boston, MA, 02115, USA.,Eaton-Peabody Laboratories, Massachusetts Eye and Ear, 243 Charles St., Boston, MA, 02114, USA
| | - Lei Tanaka
- Department of Otololaryngology, Harvard Medical School, Boston, MA, 02115, USA.,Eaton-Peabody Laboratories, Massachusetts Eye and Ear, 243 Charles St., Boston, MA, 02114, USA
| | - Yushi Hayashi
- Department of Otololaryngology, Harvard Medical School, Boston, MA, 02115, USA.,Eaton-Peabody Laboratories, Massachusetts Eye and Ear, 243 Charles St., Boston, MA, 02114, USA
| | - Takahisa Watabe
- Department of Otololaryngology, Harvard Medical School, Boston, MA, 02115, USA.,Eaton-Peabody Laboratories, Massachusetts Eye and Ear, 243 Charles St., Boston, MA, 02114, USA
| | - Hanae Lahlou
- Department of Otololaryngology, Harvard Medical School, Boston, MA, 02115, USA.,Eaton-Peabody Laboratories, Massachusetts Eye and Ear, 243 Charles St., Boston, MA, 02114, USA
| | - Kohsuke Tani
- Department of Otololaryngology, Harvard Medical School, Boston, MA, 02115, USA.,Eaton-Peabody Laboratories, Massachusetts Eye and Ear, 243 Charles St., Boston, MA, 02114, USA
| | - Albert S B Edge
- Department of Otololaryngology, Harvard Medical School, Boston, MA, 02115, USA. .,Eaton-Peabody Laboratories, Massachusetts Eye and Ear, 243 Charles St., Boston, MA, 02114, USA. .,Program in Speech and Hearing Bioscience and Technology, Harvard Medical School, Boston, MA, 02115, USA. .,Harvard Stem Cell Institute, Cambridge, MA, 02138, USA.
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197
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Raiders S, Han T, Scott-Hewitt N, Kucenas S, Lew D, Logan MA, Singhvi A. Engulfed by Glia: Glial Pruning in Development, Function, and Injury across Species. J Neurosci 2021; 41:823-833. [PMID: 33468571 PMCID: PMC7880271 DOI: 10.1523/jneurosci.1660-20.2020] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 10/20/2020] [Accepted: 10/26/2020] [Indexed: 02/07/2023] Open
Abstract
Phagocytic activity of glial cells is essential for proper nervous system sculpting, maintenance of circuitry, and long-term brain health. Glial engulfment of apoptotic cells and superfluous connections ensures that neuronal connections are appropriately refined, while clearance of damaged projections and neurotoxic proteins in the mature brain protects against inflammatory insults. Comparative work across species and cell types in recent years highlights the striking conservation of pathways that govern glial engulfment. Many signaling cascades used during developmental pruning are re-employed in the mature brain to "fine tune" synaptic architecture and even clear neuronal debris following traumatic events. Moreover, the neuron-glia signaling events required to trigger and perform phagocytic responses are impressively conserved between invertebrates and vertebrates. This review offers a compare-and-contrast portrayal of recent findings that underscore the value of investigating glial engulfment mechanisms in a wide range of species and contexts.
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Affiliation(s)
- Stephan Raiders
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109
- Molecular and Cellular Biology Graduate Program, University of Washington, Seattle, Washington 98195
| | - Taeho Han
- UCSF Weill Institute for Neurosciences, University of California San Francisco, San Francisco, California 94158
| | - Nicole Scott-Hewitt
- F.M. Kirby Center for Neurobiology, Boston Children's Hospital, Boston, Massachusetts 02115
- Stanley Center for Psychiatric Research, Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, Massachusetts 02142
| | - Sarah Kucenas
- Department of Biology, University of Virginia, Charlottesville, Virginia 22904
| | - Deborah Lew
- Department of Biological Sciences, Fordham University, Bronx, New York 10458
| | - Mary A Logan
- Jungers Center, Department of Neurology, Oregon Health and Science University, Portland, Oregon 97239
| | - Aakanksha Singhvi
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109
- Molecular and Cellular Biology Graduate Program, University of Washington, Seattle, Washington 98195
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198
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Chhatbar C, Prinz M. The roles of microglia in viral encephalitis: from sensome to therapeutic targeting. Cell Mol Immunol 2021; 18:250-258. [PMID: 33437050 PMCID: PMC7802409 DOI: 10.1038/s41423-020-00620-5] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 12/08/2020] [Indexed: 01/31/2023] Open
Abstract
Viral encephalitis is a devastating disease with high mortality, and survivors often suffer from severe neurological complications. Microglia are innate immune cells of the central nervous system (CNS) parenchyma whose turnover is reliant on local proliferation. Microglia express a diverse range of proteins, which allows them to continuously sense the environment and quickly react to changes. Under inflammatory conditions such as CNS viral infection, microglia promote innate and adaptive immune responses to protect the host. However, during viral infection, a dysregulated microglia-T-cell interplay may result in altered phagocytosis of neuronal synapses by microglia that causes neurocognitive impairment. In this review, we summarize the current knowledge on the role of microglia in viral encephalitis, propose questions to be answered in the future and suggest possible therapeutic targets.
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Affiliation(s)
- Chintan Chhatbar
- grid.5963.9Institute of Neuropathology, Medical Faculty, University of Freiburg, Freiburg, Germany
| | - Marco Prinz
- grid.5963.9Institute of Neuropathology, Medical Faculty, University of Freiburg, Freiburg, Germany ,grid.5963.9Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany ,grid.5963.9Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany
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199
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Yilmaz M, Yalcin E, Presumey J, Aw E, Ma M, Whelan CW, Stevens B, McCarroll SA, Carroll MC. Overexpression of schizophrenia susceptibility factor human complement C4A promotes excessive synaptic loss and behavioral changes in mice. Nat Neurosci 2021; 24:214-224. [PMID: 33353966 PMCID: PMC8086435 DOI: 10.1038/s41593-020-00763-8] [Citation(s) in RCA: 157] [Impact Index Per Article: 52.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2019] [Accepted: 11/20/2020] [Indexed: 12/13/2022]
Abstract
The complement component 4 (C4) gene is linked to schizophrenia and synaptic refinement. In humans, greater expression of C4A in the brain is associated with an increased risk of schizophrenia. To investigate this genetic finding and address how C4A shapes brain circuits in vivo, here, we generated a mouse model with primate-lineage-specific isoforms of C4, human C4A and/or C4B. Human C4A bound synapses more efficiently than C4B. C4A (but not C4B) rescued the visual system synaptic refinement deficits of C4 knockout mice. Intriguingly, mice without C4 had normal numbers of cortical synapses, which suggests that complement is not required for normal developmental synaptic pruning. However, overexpressing C4A in mice reduced cortical synapse density, increased microglial engulfment of synapses and altered mouse behavior. These results suggest that increased C4A-mediated synaptic elimination results in abnormal brain circuits and behavior. Understanding pathological overpruning mechanisms has important therapeutic implications in disease conditions such as schizophrenia.
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Affiliation(s)
- Melis Yilmaz
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Esra Yalcin
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Jessy Presumey
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Ernest Aw
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Minghe Ma
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Christopher W Whelan
- Department of Genetics, Harvard Medical School, Boston, MA, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Beth Stevens
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Steven A McCarroll
- Department of Genetics, Harvard Medical School, Boston, MA, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Michael C Carroll
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.
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200
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Ramaglia V, Rojas O, Naouar I, Gommerman JL. The Ins and Outs of Central Nervous System Inflammation-Lessons Learned from Multiple Sclerosis. Annu Rev Immunol 2021; 39:199-226. [PMID: 33524273 DOI: 10.1146/annurev-immunol-093019-124155] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Multiple sclerosis (MS) is a chronic disease that is characterized by the inappropriate invasion of lymphocytes and monocytes into the central nervous system (CNS), where they orchestrate the demyelination of axons, leading to physical and cognitive disability. There are many reasons immunologists should be interested in MS. Aside from the fact that there is still significant unmet need for patients living with the progressive form of the disease, MS is a case study for how immune cells cross CNS barriers and subsequently interact with specialized tissue parenchymal cells. In this review, we describe the types of immune cells that infiltrate the CNS and then describe interactions between immune cells and glial cells in different types of lesions. Lastly, we provide evidence for CNS-compartmentalized immune cells and speculate on how this impacts disease progression for MS patients.
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Affiliation(s)
- Valeria Ramaglia
- Department of Immunology, University of Toronto, Ontario M5S 1A8, Canada;
| | - Olga Rojas
- Department of Immunology, University of Toronto, Ontario M5S 1A8, Canada;
| | - Ikbel Naouar
- Department of Immunology, University of Toronto, Ontario M5S 1A8, Canada;
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