1
|
Planas AM. Role of microglia in stroke. Glia 2024; 72:1016-1053. [PMID: 38173414 DOI: 10.1002/glia.24501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 12/07/2023] [Accepted: 12/19/2023] [Indexed: 01/05/2024]
Abstract
Microglia play key roles in the post-ischemic inflammatory response and damaged tissue removal reacting rapidly to the disturbances caused by ischemia and working to restore the lost homeostasis. However, the modified environment, encompassing ionic imbalances, disruption of crucial neuron-microglia interactions, spreading depolarization, and generation of danger signals from necrotic neurons, induce morphological and phenotypic shifts in microglia. This leads them to adopt a proinflammatory profile and heighten their phagocytic activity. From day three post-ischemia, macrophages infiltrate the necrotic core while microglia amass at the periphery. Further, inflammation prompts a metabolic shift favoring glycolysis, the pentose-phosphate shunt, and lipid synthesis. These shifts, combined with phagocytic lipid intake, drive lipid droplet biogenesis, fuel anabolism, and enable microglia proliferation. Proliferating microglia release trophic factors contributing to protection and repair. However, some microglia accumulate lipids persistently and transform into dysfunctional and potentially harmful foam cells. Studies also showed microglia that either display impaired apoptotic cell clearance, or eliminate synapses, viable neurons, or endothelial cells. Yet, it will be essential to elucidate the viability of engulfed cells, the features of the local environment, the extent of tissue damage, and the temporal sequence. Ischemia provides a rich variety of region- and injury-dependent stimuli for microglia, evolving with time and generating distinct microglia phenotypes including those exhibiting proinflammatory or dysfunctional traits and others showing pro-repair features. Accurate profiling of microglia phenotypes, alongside with a more precise understanding of the associated post-ischemic tissue conditions, is a necessary step to serve as the potential foundation for focused interventions in human stroke.
Collapse
Affiliation(s)
- Anna M Planas
- Cerebrovascular Research Laboratory, Department of Neuroscience and Experimental Therapeutics, Instituto de Investigaciones Biomédicas de Barcelona (IIBB), Consejo Superior de Investigaciones Científicas (CSIC), Barcelona, Spain
- Cerebrovascular Diseases, Area of Clinical and Experimental Neuroscience, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS)-Hospital Clínic, Barcelona, Spain
| |
Collapse
|
2
|
Raffaele S, Thougaard E, Laursen CCH, Gao H, Andersen KM, Nielsen PV, Ortí-Casañ N, Blichfeldt-Eckhardt M, Koch S, Deb-Chatterji M, Magnus T, Stubbe J, Madsen K, Meyer M, Degn M, Eisel ULM, Wlodarczyk A, Fumagalli M, Clausen BH, Brambilla R, Lambertsen KL. Microglial TNFR2 signaling regulates the inflammatory response after CNS injury in a sex-specific fashion. Brain Behav Immun 2024; 116:269-285. [PMID: 38142915 DOI: 10.1016/j.bbi.2023.12.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 11/21/2023] [Accepted: 12/19/2023] [Indexed: 12/26/2023] Open
Abstract
Microglia, the resident immune cells of the central nervous system (CNS), play a major role in damage progression and tissue remodeling after acute CNS injury, including ischemic stroke (IS) and spinal cord injury (SCI). Understanding the molecular mechanisms regulating microglial responses to injury may thus reveal novel therapeutic targets to promote CNS repair. Here, we investigated the role of microglial tumor necrosis factor receptor 2 (TNFR2), a transmembrane receptor previously associated with pro-survival and neuroprotective responses, in shaping the neuroinflammatory environment after CNS injury. By inducing experimental IS and SCI in Cx3cr1CreER:Tnfrsf1bfl/fl mice, selectively lacking TNFR2 in microglia, and corresponding Tnfrsf1bfl/fl littermate controls, we found that ablation of microglial TNFR2 significantly reduces lesion size and pro-inflammatory cytokine levels, and favors infiltration of leukocytes after injury. Interestingly, these effects were paralleled by opposite sex-specific modifications of microglial reactivity, which was found to be limited in female TNFR2-ablated mice compared to controls, whereas it was enhanced in males. In addition, we show that TNFR2 protein levels in the cerebrospinal fluid (CSF) of human subjects affected by IS and SCI, as well as healthy donors, significantly correlate with disease stage and severity, representing a valuable tool to monitor the inflammatory response after acute CNS injury. Hence, these results advance our understanding of the mechanisms regulating microglia reactivity after acute CNS injury, aiding the development of sex- and microglia-specific, personalized neuroregenerative strategies.
Collapse
Affiliation(s)
- Stefano Raffaele
- Department of Neurobiology Research, Institute of Molecular Medicine, University of Southern Denmark, 5230 Odense M, Denmark; Department of Pharmacological and Biomolecular Sciences "Rodolfo Paoletti", Università degli Studi di Milano, 20133 Milan, Italy
| | - Estrid Thougaard
- Department of Neurobiology Research, Institute of Molecular Medicine, University of Southern Denmark, 5230 Odense M, Denmark
| | - Cathrine C H Laursen
- Department of Neurobiology Research, Institute of Molecular Medicine, University of Southern Denmark, 5230 Odense M, Denmark; BRIDGE-Brain Research Inter Disciplinary Guided Excellence, Department of Clinical Research, University of Southern Denmark, 5230 Odense M, Denmark
| | - Han Gao
- Department of Spine Surgery, The Third Affiliated Hospital of Sun Yat-Sen University, 510630 Guangzhou, China; Guangdong Provincial Center for Engineering and Technology Research of Minimally Invasive Spine Surgery, 510630 Guangzhou, China
| | - Katrine M Andersen
- Department of Neurobiology Research, Institute of Molecular Medicine, University of Southern Denmark, 5230 Odense M, Denmark
| | - Pernille V Nielsen
- Department of Neurobiology Research, Institute of Molecular Medicine, University of Southern Denmark, 5230 Odense M, Denmark
| | - Natalia Ortí-Casañ
- Department of Molecular Neurobiology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen 9713 AV, Netherlands
| | - Morten Blichfeldt-Eckhardt
- Department of Anaesthesiology, Vejle Hospital, 7100 Vejle, Denmark; Department of Clinical Research, University of Southern Denmark, 5230 Odense M, Denmark
| | - Simon Koch
- Department of Neurology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Milani Deb-Chatterji
- Department of Neurology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Tim Magnus
- Department of Neurology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Jane Stubbe
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, 5230 Odense M, Denmark
| | - Kirsten Madsen
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, 5230 Odense M, Denmark
| | - Morten Meyer
- Department of Neurobiology Research, Institute of Molecular Medicine, University of Southern Denmark, 5230 Odense M, Denmark; BRIDGE-Brain Research Inter Disciplinary Guided Excellence, Department of Clinical Research, University of Southern Denmark, 5230 Odense M, Denmark; Department of Neurology, Odense University Hospital, 5000 Odense C, Denmark
| | | | - Ulrich L M Eisel
- Department of Molecular Neurobiology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen 9713 AV, Netherlands
| | - Agnieszka Wlodarczyk
- Department of Neurobiology Research, Institute of Molecular Medicine, University of Southern Denmark, 5230 Odense M, Denmark; BRIDGE-Brain Research Inter Disciplinary Guided Excellence, Department of Clinical Research, University of Southern Denmark, 5230 Odense M, Denmark
| | - Marta Fumagalli
- Department of Pharmacological and Biomolecular Sciences "Rodolfo Paoletti", Università degli Studi di Milano, 20133 Milan, Italy
| | - Bettina H Clausen
- Department of Neurobiology Research, Institute of Molecular Medicine, University of Southern Denmark, 5230 Odense M, Denmark; BRIDGE-Brain Research Inter Disciplinary Guided Excellence, Department of Clinical Research, University of Southern Denmark, 5230 Odense M, Denmark
| | - Roberta Brambilla
- BRIDGE-Brain Research Inter Disciplinary Guided Excellence, Department of Clinical Research, University of Southern Denmark, 5230 Odense M, Denmark; The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami FL, USA.
| | - Kate L Lambertsen
- Department of Neurobiology Research, Institute of Molecular Medicine, University of Southern Denmark, 5230 Odense M, Denmark; BRIDGE-Brain Research Inter Disciplinary Guided Excellence, Department of Clinical Research, University of Southern Denmark, 5230 Odense M, Denmark; Department of Neurology, Odense University Hospital, 5000 Odense C, Denmark.
| |
Collapse
|
3
|
Jia J, Zheng L, Ye L, Chen J, Shu S, Xu S, Bao X, Xia S, Liu R, Xu Y, Zhang M. CD11c + microglia promote white matter repair after ischemic stroke. Cell Death Dis 2023; 14:156. [PMID: 36828819 PMCID: PMC9958101 DOI: 10.1038/s41419-023-05689-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Revised: 02/14/2023] [Accepted: 02/15/2023] [Indexed: 02/26/2023]
Abstract
Ischemic stroke leads to white matter damage and neurological deficits. However, the characteristics of white matter injury and repair after stroke are unclear. Additionally, the precise molecular communications between microglia and white matter repair during the stroke rehabilitation phase remain elusive. In this current study, MRI DTI scan and immunofluorescence staining were performed to trace white matter and microglia in the mouse transient middle cerebral artery occlusion (tMCAO) stroke model. We found that the most serious white matter damage was on Day 7 after the ischemic stroke, then it recovered gradually from Day 7 to Day 30. Parallel to white matter recovery, we observed that microglia centered around the damaged myelin sheath and swallowed myelin debris in the ischemic areas. Then, microglia of the ischemic hemisphere were sorted by flow cytometry for RNA sequencing and subpopulation analysis. We found that CD11c+ microglia increased from Day 7 to Day 30, demonstrating high phagocytotic capabilities, myelin-supportive genes, and lipid metabolism associated genes. CD11c+ microglia population was partly depleted by the stereotactic injecting of rAAV2/6M-taCasp3 (rAAV2/6M-CMV-DIO-taCasp3-TEVp) into CD11c-cre mice. Selective depletion of CD11c+ microglia disrupted white matter repair, oligodendrocyte maturation, and functional recovery after stroke by Rotarod test, Adhesive Removal test, and Morris Water Maze test. These findings suggest that spontaneous white matter repair occurs after ischemic stroke, while CD11c+ microglia play critical roles in this white matter restorative progress.
Collapse
Affiliation(s)
- Junqiu Jia
- Department of Neurology, Drum Tower Hospital, The State Key Laboratory of Pharmaceutical Biotechnology, Institute of Brain Science, Medical School, Nanjing University, Nanjing, China
| | - Lili Zheng
- Department of Neurology, Drum Tower Hospital, The State Key Laboratory of Pharmaceutical Biotechnology, Institute of Brain Science, Medical School, Nanjing University, Nanjing, China
| | - Lei Ye
- Department of Neurology, Drum Tower Hospital, The State Key Laboratory of Pharmaceutical Biotechnology, Institute of Brain Science, Medical School, Nanjing University, Nanjing, China
| | - Jian Chen
- Department of Neurology, Drum Tower Hospital, The State Key Laboratory of Pharmaceutical Biotechnology, Institute of Brain Science, Medical School, Nanjing University, Nanjing, China
| | - Shu Shu
- Department of Neurology, Drum Tower Hospital, The State Key Laboratory of Pharmaceutical Biotechnology, Institute of Brain Science, Medical School, Nanjing University, Nanjing, China
| | - Siyi Xu
- Department of Neurology, Nanjing Drum Tower Hospital Clinical College of Jiangsu University, Zhenjiang, China
| | - Xinyu Bao
- Department of Neurology, Drum Tower Hospital, The State Key Laboratory of Pharmaceutical Biotechnology, Institute of Brain Science, Medical School, Nanjing University, Nanjing, China
| | - Shengnan Xia
- Department of Neurology, Drum Tower Hospital, The State Key Laboratory of Pharmaceutical Biotechnology, Institute of Brain Science, Medical School, Nanjing University, Nanjing, China
| | - Renyuan Liu
- Department of Radiology, Affiliated Nanjing Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Yun Xu
- Department of Neurology, Drum Tower Hospital, The State Key Laboratory of Pharmaceutical Biotechnology, Institute of Brain Science, Medical School, Nanjing University, Nanjing, China.
- Jiangsu Key Laboratory for Molecular Medicine, Medical School of Nanjing University, Nanjing, China.
- Jiangsu Province Stroke Center for Diagnosis and Therapy, Nanjing, China.
- Nanjing Neuropsychiatry Clinic Medical Center, Nanjing, China.
| | - Meijuan Zhang
- Department of Neurology, Drum Tower Hospital, The State Key Laboratory of Pharmaceutical Biotechnology, Institute of Brain Science, Medical School, Nanjing University, Nanjing, China.
- Jiangsu Key Laboratory for Molecular Medicine, Medical School of Nanjing University, Nanjing, China.
- Jiangsu Province Stroke Center for Diagnosis and Therapy, Nanjing, China.
- Nanjing Neuropsychiatry Clinic Medical Center, Nanjing, China.
| |
Collapse
|
4
|
Göttle P, Groh J, Reiche L, Gruchot J, Rychlik N, Werner L, Samper Agrelo I, Akkermann R, Zink A, Prigione A, Hartung HP, Martini R, Küry P. Teriflunomide as a therapeutic means for myelin repair. J Neuroinflammation 2023; 20:7. [PMID: 36611185 PMCID: PMC9826576 DOI: 10.1186/s12974-022-02686-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Accepted: 12/23/2022] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Promotion of myelin repair in the context of demyelinating diseases such as multiple sclerosis (MS) still represents a clinical unmet need, given that this disease is not only characterized by autoimmune activities but also by impaired regeneration processes. Hence, this relates to replacement of lost oligodendrocytes and myelin sheaths-the primary targets of autoimmune attacks. Endogenous remyelination is mainly mediated via activation and differentiation of resident oligodendroglial precursor cells (OPCs), whereas its efficiency remains limited and declines with disease progression and aging. Teriflunomide has been approved as a first-line treatment for relapsing remitting MS. Beyond its role in acting via inhibition of de novo pyrimidine synthesis leading to a cytostatic effect on proliferating lymphocyte subsets, this study aims to uncover its potential to foster myelin repair. METHODS Within the cuprizone mediated de-/remyelination model teriflunomide dependent effects on oligodendroglial homeostasis and maturation, related to cellular processes important for myelin repair were analyzed in vivo. Teriflunomide administration was performed either as pulse or continuously and markers specific for oligodendroglial maturation and mitochondrial integrity were examined by means of gene expression and immunohistochemical analyses. In addition, axon myelination was determined using electron microscopy. RESULTS Both pulse and constant teriflunomide treatment efficiently boosted myelin repair activities in this model, leading to accelerated generation of oligodendrocytes and restoration of myelin sheaths. Moreover, teriflunomide restored mitochondrial integrity within oligodendroglial cells. CONCLUSIONS The link between de novo pyrimidine synthesis inhibition, oligodendroglial rescue, and maintenance of mitochondrial homeostasis appears as a key for successful myelin repair and hence for protection of axons from degeneration.
Collapse
Affiliation(s)
- Peter Göttle
- grid.411327.20000 0001 2176 9917Department of Neurology, Medical Faculty, Heinrich-Heine-University, Moorenstrasse 5, 40225 Düsseldorf, Germany
| | - Janos Groh
- grid.411760.50000 0001 1378 7891Department of Neurology, Section of Developmental Neurobiology, University Hospital, Würzburg, Germany
| | - Laura Reiche
- grid.411327.20000 0001 2176 9917Department of Neurology, Medical Faculty, Heinrich-Heine-University, Moorenstrasse 5, 40225 Düsseldorf, Germany
| | - Joel Gruchot
- grid.411327.20000 0001 2176 9917Department of Neurology, Medical Faculty, Heinrich-Heine-University, Moorenstrasse 5, 40225 Düsseldorf, Germany
| | - Nicole Rychlik
- grid.411327.20000 0001 2176 9917Department of Neurology, Medical Faculty, Heinrich-Heine-University, Moorenstrasse 5, 40225 Düsseldorf, Germany
| | - Luisa Werner
- grid.411327.20000 0001 2176 9917Department of Neurology, Medical Faculty, Heinrich-Heine-University, Moorenstrasse 5, 40225 Düsseldorf, Germany
| | - Iria Samper Agrelo
- grid.411327.20000 0001 2176 9917Department of Neurology, Medical Faculty, Heinrich-Heine-University, Moorenstrasse 5, 40225 Düsseldorf, Germany
| | - Rainer Akkermann
- grid.411327.20000 0001 2176 9917Department of Neurology, Medical Faculty, Heinrich-Heine-University, Moorenstrasse 5, 40225 Düsseldorf, Germany
| | - Annika Zink
- grid.411327.20000 0001 2176 9917Department of General Pediatrics, Neonatology and Pediatric Cardiology, Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany
| | - Alessandro Prigione
- grid.411327.20000 0001 2176 9917Department of General Pediatrics, Neonatology and Pediatric Cardiology, Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany
| | - Hans-Peter Hartung
- grid.411327.20000 0001 2176 9917Department of Neurology, Medical Faculty, Heinrich-Heine-University, Moorenstrasse 5, 40225 Düsseldorf, Germany ,grid.1013.30000 0004 1936 834XBrain and Mind Center, University of Sydney, Sydney, Australia ,grid.10979.360000 0001 1245 3953Department of Neurology, Palacky University Olomouc, Olomouc, Czech Republic
| | - Rudolf Martini
- grid.411760.50000 0001 1378 7891Department of Neurology, Section of Developmental Neurobiology, University Hospital, Würzburg, Germany
| | - Patrick Küry
- grid.411327.20000 0001 2176 9917Department of Neurology, Medical Faculty, Heinrich-Heine-University, Moorenstrasse 5, 40225 Düsseldorf, Germany
| |
Collapse
|
5
|
Peng L, Hu G, Yao Q, Wu J, He Z, Law BYK, Hu G, Zhou X, Du J, Wu A, Yu L. Microglia autophagy in ischemic stroke: A double-edged sword. Front Immunol 2022; 13:1013311. [PMID: 36466850 PMCID: PMC9708732 DOI: 10.3389/fimmu.2022.1013311] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2022] [Accepted: 10/25/2022] [Indexed: 08/14/2023] Open
Abstract
Ischemic stroke (IS) is one of the major types of cerebrovascular diseases causing neurological morbidity and mortality worldwide. In the pathophysiological process of IS, microglia play a beneficial role in tissue repair. However, it could also cause cellular damage, consequently leading to cell death. Inflammation is characterized by the activation of microglia, and increasing evidence showed that autophagy interacts with inflammation through regulating correlative mediators and signaling pathways. In this paper, we summarized the beneficial and harmful effects of microglia in IS. In addition, we discussed the interplay between microglia autophagy and ischemic inflammation, as along with its application in the treatment of IS. We believe this could help to provide the theoretical references for further study into IS and treatments in the future.
Collapse
Affiliation(s)
- Li Peng
- Sichuan Key Medical Laboratory of New Drug Discovery and Druggability Evaluation, School of Pharmacy, Southwest Medical University, Luzhou, China
- Luzhou Key Laboratory of Activity Screening and Druggability Evaluation for Chinese Materia Medica, School of Pharmacy, Southwest Medical University, Luzhou, China
- Department of Medicine Imaging, School of Clinical Medicine, Southwest Medical University, Luzhou, China
| | - Guangqiang Hu
- Department of Anatomy, School of Basic Medical Sciences, Southwest Medical University, Luzhou, China
| | - Qianfang Yao
- Sichuan Key Medical Laboratory of New Drug Discovery and Druggability Evaluation, School of Pharmacy, Southwest Medical University, Luzhou, China
- Luzhou Key Laboratory of Activity Screening and Druggability Evaluation for Chinese Materia Medica, School of Pharmacy, Southwest Medical University, Luzhou, China
| | - Jianming Wu
- Sichuan Key Medical Laboratory of New Drug Discovery and Druggability Evaluation, School of Pharmacy, Southwest Medical University, Luzhou, China
- Luzhou Key Laboratory of Activity Screening and Druggability Evaluation for Chinese Materia Medica, School of Pharmacy, Southwest Medical University, Luzhou, China
| | - Ziyang He
- Sichuan Key Medical Laboratory of New Drug Discovery and Druggability Evaluation, School of Pharmacy, Southwest Medical University, Luzhou, China
- Luzhou Key Laboratory of Activity Screening and Druggability Evaluation for Chinese Materia Medica, School of Pharmacy, Southwest Medical University, Luzhou, China
| | - Betty Yuen-Kwan Law
- State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Macao, Macao SAR, China
| | - Guishan Hu
- Sichuan Key Medical Laboratory of New Drug Discovery and Druggability Evaluation, School of Pharmacy, Southwest Medical University, Luzhou, China
- Luzhou Key Laboratory of Activity Screening and Druggability Evaluation for Chinese Materia Medica, School of Pharmacy, Southwest Medical University, Luzhou, China
| | - Xiaogang Zhou
- Sichuan Key Medical Laboratory of New Drug Discovery and Druggability Evaluation, School of Pharmacy, Southwest Medical University, Luzhou, China
- Luzhou Key Laboratory of Activity Screening and Druggability Evaluation for Chinese Materia Medica, School of Pharmacy, Southwest Medical University, Luzhou, China
| | - Junrong Du
- Key Laboratory of Drug Targeting and Drug Delivery Systems of Ministry of Education, Department of Pharmacology, West China School of Pharmacy, Sichuan University, Chengdu, China
| | - Anguo Wu
- Sichuan Key Medical Laboratory of New Drug Discovery and Druggability Evaluation, School of Pharmacy, Southwest Medical University, Luzhou, China
- Luzhou Key Laboratory of Activity Screening and Druggability Evaluation for Chinese Materia Medica, School of Pharmacy, Southwest Medical University, Luzhou, China
| | - Lu Yu
- Sichuan Key Medical Laboratory of New Drug Discovery and Druggability Evaluation, School of Pharmacy, Southwest Medical University, Luzhou, China
- Luzhou Key Laboratory of Activity Screening and Druggability Evaluation for Chinese Materia Medica, School of Pharmacy, Southwest Medical University, Luzhou, China
- Department of Medicine Imaging, School of Clinical Medicine, Southwest Medical University, Luzhou, China
- Department of Chemistry, School of Basic Medical Sciences, Southwest Medical University, Luzhou, China
| |
Collapse
|
6
|
Gabrielli M, Raffaele S, Fumagalli M, Verderio C. The multiple faces of extracellular vesicles released by microglia: Where are we 10 years after? Front Cell Neurosci 2022; 16:984690. [PMID: 36176630 PMCID: PMC9514840 DOI: 10.3389/fncel.2022.984690] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Accepted: 08/23/2022] [Indexed: 11/30/2022] Open
Abstract
As resident component of the innate immunity in the central nervous system (CNS), microglia are key players in pathology. However, they also exert fundamental roles in brain development and homeostasis maintenance. They are extremely sensitive and plastic, as they assiduously monitor the environment, adapting their function in response to stimuli. On consequence, microglia may be defined a heterogeneous community of cells in a dynamic equilibrium. Extracellular vesicles (EVs) released by microglia mirror the dynamic nature of their donor cells, exerting important and versatile functions in the CNS as unbounded conveyors of bioactive signals. In this review, we summarize the current knowledge on EVs released by microglia, highlighting their heterogeneous properties and multifaceted effects.
Collapse
Affiliation(s)
- Martina Gabrielli
- CNR Institute of Neuroscience, Vedano al Lambro, Italy
- *Correspondence: Martina Gabrielli,
| | - Stefano Raffaele
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan, Italy
| | - Marta Fumagalli
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan, Italy
| | - Claudia Verderio
- CNR Institute of Neuroscience, Vedano al Lambro, Italy
- Claudia Verderio,
| |
Collapse
|
7
|
Raffaele S, Fumagalli M. Dynamics of Microglia Activation in the Ischemic Brain: Implications for Myelin Repair and Functional Recovery. Front Cell Neurosci 2022; 16:950819. [PMID: 35899017 PMCID: PMC9309466 DOI: 10.3389/fncel.2022.950819] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 06/14/2022] [Indexed: 11/13/2022] Open
Abstract
Ischemic stroke is a neurological disorder representing a leading cause of death and permanent disability world-wide, for which effective regenerative treatments are missing. Oligodendrocyte degeneration and consequent myelin disruption are considered major contributing factors to stroke-associated neurological deficits. Therefore, fostering myelin reconstruction by oligodendrocyte precursor cells (OPCs) has emerged as a promising therapeutic approach to enhance functional recovery in stroke patients. A pivotal role in regulating remyelination is played by microglia, the resident immune cells of the brain. Early after stroke, microglial cells exert beneficial functions, promoting OPC recruitment toward the ischemic lesion and preserving myelin integrity. However, the protective features of microglia are lost during disease progression, contributing to remyelination failure. Unveiling the mechanisms driving the pro-remyelination properties of microglia may provide important opportunities for both reducing myelin damage and promoting its regeneration. Here, we summarize recent evidence describing microglia activation kinetics in experimental models of ischemic injury, focusing on the contribution of these innate immune cells to myelin damage and repair. Some molecular signals regulating the pro-regenerative functions of microglia after stroke have been highlighted to provide new possible therapeutic targets involved in the protective functions of these cells. Finally, we analyzed the impact of microglia-to-OPCs communication via extracellular vesicles on post-stroke remyelination and functional recovery. The results collected in this review underline the importance of supporting the pro-remyelination functions of microglial cells after stroke.
Collapse
|
8
|
Liu C, Han S, Zheng J, Wang H, Li S, Li J. EphA4 regulates white matter remyelination after ischemic stroke through Ephexin-1/RhoA/ROCK signaling pathway. Glia 2022; 70:1971-1991. [PMID: 35762396 DOI: 10.1002/glia.24232] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 06/06/2022] [Accepted: 06/16/2022] [Indexed: 11/07/2022]
Abstract
Ischemic stroke, which accounts for nearly 80% of all strokes, leads to white matter injury and neurobehavioral dysfunction, but relevant therapies to inhibit demyelination or promote remyelination after white matter injury are still unavailable. In this study, the middle cerebral artery occlusion/reperfusion (MCAO/R) in vivo and oxygen-glucose deprivation/reoxygenation (OGD/R) in vitro were used to establish the ischemic models. We found that Eph receptor A4 (EphA4) had no effect on the apoptosis of oligodendrocytes using TUNEL staining. In contrast, EphA4 promoted proliferation of oligodendrocyte precursor cells (OPCs), but reduced the numbers of mature oligodendrocytes and the levels of myelin-associated proteins (MAG, MOG, and MBP) in the process of remyelination in ischemic models in vivo and in vitro as determined using PDGFRα-EphA4-shRNA and LV-EphA4 treatments. Notably, conditional knockout of EphA4 in OPCs (EphA4fl/fl + AAV-PDGFRα-Cre) improved the levels of myelin-associated proteins and functional recovery following ischemic stroke. In addition, regulation of remyelination by EphA4 was mediated by the Ephexin-1/RhoA/ROCK signaling pathway. Therefore, EphA4 did not affect oligodendrocyte (OL) apoptosis but regulated white matter remyelination after ischemic stroke through the Ephexin-1/RhoA/ROCK signaling pathway. EphA4 may provide a novel and effective therapeutic target in clinical practice of ischemic stroke.
Collapse
Affiliation(s)
- Cui Liu
- Department of Neurobiology and Center of Stroke, Beijing Institute for Brain Disorders, School of Basic Medical Science, Capital Medical University, Beijing, China
| | - Song Han
- Department of Neurobiology and Center of Stroke, Beijing Institute for Brain Disorders, School of Basic Medical Science, Capital Medical University, Beijing, China
| | - Jiayin Zheng
- Department of Neurobiology and Center of Stroke, Beijing Institute for Brain Disorders, School of Basic Medical Science, Capital Medical University, Beijing, China
| | - Hongyu Wang
- Department of Neurobiology and Center of Stroke, Beijing Institute for Brain Disorders, School of Basic Medical Science, Capital Medical University, Beijing, China
| | - Shujuan Li
- The Neurological Department, Fu Wai Hospital, National Center for Cardiovascular Diseases, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Junfa Li
- Department of Neurobiology and Center of Stroke, Beijing Institute for Brain Disorders, School of Basic Medical Science, Capital Medical University, Beijing, China
| |
Collapse
|