951
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Antonson AM, Balakrishnan B, Radlowski EC, Petr G, Johnson RW. Altered Hippocampal Gene Expression and Morphology in Fetal Piglets following Maternal Respiratory Viral Infection. Dev Neurosci 2018. [PMID: 29539630 DOI: 10.1159/000486850] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Maternal infection during pregnancy increases the risk of neurobehavioral problems in offspring. Evidence from rodent models indicates that the maternal immune response to infection can alter fetal brain development, particularly in the hippocampus. However, information on the effects of maternal viral infection on fetal brain development in gyrencephalic species is limited. Thus, the objective of this study was to assess several effects of maternal viral infection in the last one-third of gestation on hippocampal gene expression and development in fetal piglets. Pregnant gilts were inoculated with porcine reproductive and respiratory syndrome virus (PRRSV) at gestational day (GD) 76 and the fetuses were removed by cesarean section at GD 111 (3 days before anticipated parturition). The gilts infected with PRRSV had elevated plasma interleukin-6 levels and developed transient febrile and anorectic responses lasting approximately 21 days. Despite having a similar overall body weight, fetuses from the PRRSV-infected gilts had a decreased brain weight and altered hippocampal gene expression compared to fetuses from control gilts. Notably, maternal infection caused a reduction in estimated neuronal numbers in the fetal dentate gyrus and subiculum. The number of proliferative Ki-67+ cells was not altered, but the relative integrated density of GFAP+ staining was increased, in addition to an increase in GFAP gene expression, indicating astrocyte-specific gliosis. Maternal viral infection caused an increase in fetal hippocampal gene expression of the inflammatory cytokines TNF-α and IFN-γ and the myelination marker myelin basic protein. MHCII protein, a classic monocyte activation marker, was reduced in microglia, while expression of the MHCII gene was decreased in hippocampal tissue of the fetuses from PRRSV-infected gilts. Together, these data suggest that maternal viral infection at the beginning of the last trimester results in a reduction in fetal hippocampal neurons that is evident 5 weeks after infection, when fetal piglets are near full term. The neuronal reduction was not accompanied by pronounced neuroinflammation at GD 111, indicating that any activation of classic neuroinflammatory pathways by maternal viral infection, if present, is mostly resolved by parturition.
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Affiliation(s)
- Adrienne M Antonson
- Department of Animal Sciences, Laboratory of Integrative Immunology and Behavior, University of Illinois Urbana-Champaign, Urbana, Illinois, USA
| | - Bindu Balakrishnan
- Department of Animal Sciences, Laboratory of Integrative Immunology and Behavior, University of Illinois Urbana-Champaign, Urbana, Illinois, USA
| | - Emily C Radlowski
- Department of Animal Sciences, Laboratory of Integrative Immunology and Behavior, University of Illinois Urbana-Champaign, Urbana, Illinois, USA
| | - Geraldine Petr
- Department of Animal Sciences, Laboratory of Integrative Immunology and Behavior, University of Illinois Urbana-Champaign, Urbana, Illinois, USA
| | - Rodney W Johnson
- Department of Animal Sciences, Laboratory of Integrative Immunology and Behavior, University of Illinois Urbana-Champaign, Urbana, Illinois, USA.,Division of Nutritional Sciences, University of Illinois Urbana-Champaign, Urbana, Illinois, USA.,Neuroscience Program, University of Illinois Urbana-Champaign, Urbana, Illinois, USA
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952
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Abstract
Microglia are the principle immune cells of the brain. Once activated, microglial cells may exhibit a wide repertoire of the context-dependent profiles ranging from highly neurotoxic to more protective and pro-regenerative cellular phenotypes. While to date the mechanisms involved in the molecular regulation of the microglia polarization phenotypes remain elusive, growing evidence suggests that gender may markedly affect the inflammatory and/or glial responses following brain injuries. In the recent years, special attention has been given to the role of microglia in sexual dimorphism, both in healthy brain and diseased brain. Here, we review recent advances revealing microglia as an important determinant of gender differences under physiological conditions and in injured brain. We also discuss how microglia-driven innate immunity and signaling pathways might be involved in the sex-dependent responses following brain ischemic injury. Finally we describe how advanced methods such as live imaging techniques may help elucidate the role of microglia in the modulation of immune responses and gender difference after stroke.
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Affiliation(s)
- Reza Rahimian
- Department of Psychiatry and Neuroscience, Faculty of Medicine, CERVO Brain Research Centre, Laval University, Quebec, Quebec G1J 2G3, Canada
| | - Pierre Cordeau
- Department of Psychiatry and Neuroscience, Faculty of Medicine, CERVO Brain Research Centre, Laval University, Quebec, Quebec G1J 2G3, Canada
| | - Jasna Kriz
- Department of Psychiatry and Neuroscience, Faculty of Medicine, CERVO Brain Research Centre, Laval University, Quebec, Quebec G1J 2G3, Canada.
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953
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Single-cell mass cytometry reveals distinct populations of brain myeloid cells in mouse neuroinflammation and neurodegeneration models. Nat Neurosci 2018; 21:541-551. [DOI: 10.1038/s41593-018-0100-x] [Citation(s) in RCA: 192] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 01/21/2018] [Indexed: 12/26/2022]
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954
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Rangaraju S, Raza SA, Li NX, Betarbet R, Dammer EB, Duong D, Lah JJ, Seyfried NT, Levey AI. Differential Phagocytic Properties of CD45 low Microglia and CD45 high Brain Mononuclear Phagocytes-Activation and Age-Related Effects. Front Immunol 2018; 9:405. [PMID: 29552013 PMCID: PMC5840283 DOI: 10.3389/fimmu.2018.00405] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 02/14/2018] [Indexed: 12/20/2022] Open
Abstract
In the central nervous system (CNS), microglia are innate immune mononuclear phagocytes (CNS MPs) that can phagocytose infectious particles, apoptotic cells, neurons, and pathological protein aggregates, such as Aβ in Alzheimer’s disease (AD). While CD11b+CD45low microglia account for the majority of CNS MPs, a small population of CD11b+CD45high CNS MPs is also recognized in AD that surround Aβ plaques. These transcriptionally and pathologically unique CD45high cells have unclear origin and undefined phagocytic characteristics. We have comprehensively validated rapid flow cytometric assays of bulk-phase and amyloid β fibril (fAβ) phagocytosis and applied these to study acutely isolated CNS MPs. Using these methods, we provide novel insights into differential abilities of CD11b+ CD45low and CD45high CNS MPs to phagocytose macroparticles and fAβ under normal, acute, and chronic neuroinflammatory states. CD45high CNS MPs also highly upregulate TREM2, CD11c, and several disease-associated microglia signature genes and have a higher phagocytic capacity for Aβ as compared to CD45low microglia in the 5xFAD mouse model of AD that becomes more apparent with aging. Our data suggest an overall pro-phagocytic and protective role for CD11b+CD45high CNS MPs in neurodegeneration, which if promoted, could be beneficial.
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Affiliation(s)
- Srikant Rangaraju
- Department of Neurology, Emory University, Atlanta, GA, United States
| | - Syed Ali Raza
- Department of Neurology, Emory University, Atlanta, GA, United States
| | - Noel Xiang'An Li
- Department of Chemistry, Emory University, Atlanta, GA, United States
| | - Ranjita Betarbet
- Department of Neurology, Emory University, Atlanta, GA, United States
| | - Eric B Dammer
- Department of Neurology, Emory University, Atlanta, GA, United States
| | - Duc Duong
- Department of Biochemistry, Emory University, Atlanta, GA, United States
| | - James J Lah
- Department of Neurology, Emory University, Atlanta, GA, United States
| | | | - Allan I Levey
- Department of Neurology, Emory University, Atlanta, GA, United States
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955
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Bisphenol A exposure induces increased microglia and microglial related factors in the murine embryonic dorsal telencephalon and hypothalamus. Toxicol Lett 2018; 284:113-119. [DOI: 10.1016/j.toxlet.2017.12.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 11/24/2017] [Accepted: 12/13/2017] [Indexed: 11/22/2022]
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956
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Vanderwall AG, Noor S, Sun MS, Sanchez JE, Yang XO, Jantzie LL, Mellios N, Milligan ED. Effects of spinal non-viral interleukin-10 gene therapy formulated with d-mannose in neuropathic interleukin-10 deficient mice: Behavioral characterization, mRNA and protein analysis in pain relevant tissues. Brain Behav Immun 2018; 69:91-112. [PMID: 29113923 PMCID: PMC5857419 DOI: 10.1016/j.bbi.2017.11.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 10/20/2017] [Accepted: 11/03/2017] [Indexed: 12/17/2022] Open
Abstract
Studies show that spinal (intrathecal; i.t.) interleukin-10 (IL-10) gene therapy reverses neuropathic pain in animal models, and co-administration with the mannose receptor (MR; CD206) ligand d-mannose (DM) greatly improves therapeutic efficacy. However, the actions of endogenous IL-10 may be required for enduring pain control observed following i.t. IL-10 gene therapy, potentially narrowing the application of this non-viral transgene delivery approach. Here, we show that i.t. application of naked plasmid DNA expressing the IL-10 transgene co-injected with DM (DM/pDNA-IL-10) for the treatment of peripheral neuropathic pain in IL-10 deficient (IL-10 KO) mice results in a profound and prolonged bilateral pain suppression. Neuropathic pain is induced by unilateral sciatic chronic constriction injury (CCI), and while enduring relief of light touch sensitivity (mechanical allodynia) in both wild type (WT) and IL-10 KO mice was observed following DM/pDNA-IL-10 co-therapy, transient reversal from allodynia was observed following i.t. DM alone. In stably pain-relieved IL-10 KO mice given DM/pDNA-IL-10, mRNA for the IL-10 transgene is detected in the cauda equina and ipsilateral dorsal root ganglia (DRG), but not the lumbar spinal cord. Further, DM/pDNA-IL-10 application increases anti-inflammatory TGF-β1 and decreases pro-inflammatory TNF mRNA in the ipsilateral DRG compared to allodynic controls. Additionally, DM/pDNA-IL-10 treated mice exhibit decreased spinal pro-inflammatory mRNA expression for TNF, CCL2 (MCP-1), and for the microglial-specific marker TMEM119. Similarly, DM/pDNA-IL-10 treatment decreases immunoreactivity for the astrocyte activation marker GFAP in lumbar spinal cord dorsal horn. Despite transient reversal and early return to allodynia in DM-treated mice, lumbar spinal cord revealed elevated TNF, CCL2 and TMEM119 mRNA levels. Both MR (CD206) and IL-10 receptor mRNAs are increased in the DRG following CCI manipulation independent of injection treatment, suggesting that pathological conditions stimulate upregulation and availability of relevant receptors in critical anatomical regions required for the therapeutic actions of the DM/pDNA-IL-10 co-therapy. Taken together, the current report demonstrates that non-viral DM/pDNA-IL-10 gene therapy does not require endogenous IL-10 for enduring relief of peripheral neuropathic pain and does not require direct contact with the spinal cord dorsal horn for robust and enduring relief of neuropathic pain. Spinal non-viral DM/pDNA-IL-10 co-therapy may offer a framework for the development of non-viral gene therapeutic approaches for other diseases of the central nervous system.
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Affiliation(s)
- Arden G Vanderwall
- Department of Neurosciences, University of New Mexico School of Medicine, UNM Health Sciences Center, Albuquerque, NM 87131-0001, USA; Department of Anesthesiology & Critical Care Medicine, University of New Mexico School of Medicine, UNM Health Sciences Center, Albuquerque, NM 87131-0001, USA
| | - Shahani Noor
- Department of Neurosciences, University of New Mexico School of Medicine, UNM Health Sciences Center, Albuquerque, NM 87131-0001, USA
| | - Melody S Sun
- Department of Neurosciences, University of New Mexico School of Medicine, UNM Health Sciences Center, Albuquerque, NM 87131-0001, USA
| | - Jacob E Sanchez
- Department of Neurosciences, University of New Mexico School of Medicine, UNM Health Sciences Center, Albuquerque, NM 87131-0001, USA
| | - Xuexian O Yang
- Department of Molecular Genetics and Microbiology, University of New Mexico School of Medicine, UNM Health Sciences Center, Albuquerque, NM 87131-0001, USA
| | - Lauren L Jantzie
- Department of Neurosciences, University of New Mexico School of Medicine, UNM Health Sciences Center, Albuquerque, NM 87131-0001, USA; Department of Pediatrics, University of New Mexico School of Medicine, UNM Health Sciences Center, Albuquerque, NM 87131-0001, USA
| | - Nikolaos Mellios
- Department of Neurosciences, University of New Mexico School of Medicine, UNM Health Sciences Center, Albuquerque, NM 87131-0001, USA
| | - Erin D Milligan
- Department of Neurosciences, University of New Mexico School of Medicine, UNM Health Sciences Center, Albuquerque, NM 87131-0001, USA; Department of Anesthesiology & Critical Care Medicine, University of New Mexico School of Medicine, UNM Health Sciences Center, Albuquerque, NM 87131-0001, USA.
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957
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The impact of metallothionein-II on microglial response to tumor necrosis factor-alpha (TNFα) and downstream effects on neuronal regeneration. J Neuroinflammation 2018; 15:56. [PMID: 29471847 PMCID: PMC5822550 DOI: 10.1186/s12974-018-1070-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Accepted: 01/18/2018] [Indexed: 11/18/2022] Open
Abstract
Background The extracellular environment plays an important role in supporting the regeneration of axons after injury. Metallothionein-II (MTII) is a metal-binding protein known for its neuroprotective effect by directly stimulating the growth of axons after injury. Previous studies have shown that MTII also modulates the response of astrocytes and microglia after injury. However, a detailed analysis describing how MTII modulates the interaction between microglia and neurons is lacking. Methods We introduced fluorescently labelled MTII into the cortex at the time of needlestick injury to investigate the cellular uptake of MTII using immunohistochemistry with antibodies against cell-type-specific markers. The role of MTII in modulating the effect of microglia on axon outgrowth following an inflammatory response is further investigated using a co-culture model involving primary rodent microglia pre-treated with TNFα and primary rodent cortical neurons. The axon lengths were assessed 24 h after the plating of the neurons onto treated microglia. We also utilised siRNA to knockdown the expression of LRP1, which allows us to investigate the role of LRP1 receptors in the MTII-mediated effect of microglia on axon outgrowth. Results Fluorescently labelled MTII was found to be associated with neurons, astrocytes and microglia following injury in vivo. Microglia-neuron co-culture experiments demonstrated that exogenous MTII altered the response of microglia to TNFα. The neurons plated onto the TNFα-stimulated microglia pre-treated with MTII have shown a significantly longer axonal length compare to the TNFα-stimulated microglia without the MTII treatment. This suggested that MTII reduce cytokine-stimulated activation of microglia, which would ordinarily impair neurite outgrowth. This inhibitory effect of MTII on activated microglia was blocked by siRNA-mediated downregulation of LRP1 receptor expression in microglia, suggesting that MTII acts via the LRP1 receptor on microglia. Conclusions This study demonstrates that exogenous MTII acts via the LRP1 receptor to alter the inflammatory response of microglia following TNFα stimulation, providing a more supportive environment for axon growth.
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958
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Beckmann N, Giorgetti E, Neuhaus A, Zurbruegg S, Accart N, Smith P, Perdoux J, Perrot L, Nash M, Desrayaud S, Wipfli P, Frieauff W, Shimshek DR. Brain region-specific enhancement of remyelination and prevention of demyelination by the CSF1R kinase inhibitor BLZ945. Acta Neuropathol Commun 2018; 6:9. [PMID: 29448957 PMCID: PMC5815182 DOI: 10.1186/s40478-018-0510-8] [Citation(s) in RCA: 91] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Accepted: 01/26/2018] [Indexed: 11/10/2022] Open
Abstract
Multiple sclerosis (MS) is a chronic inflammatory disease affecting the central nervous system (CNS). While multiple effective immunomodulatory therapies for MS exist today, they lack the scope of promoting CNS repair, in particular remyelination. Microglia play a pivotal role in regulating myelination processes, and the colony-stimulating factor 1 (CSF-1) pathway is a key regulator for microglia differentiation and survival. Here, we investigated the effects of the CSF-1 receptor kinase inhibitor, BLZ945, on central myelination processes in the 5-week murine cuprizone model by non-invasive and longitudinal magnetic resonance imaging (MRI) and histology. Therapeutic 2-week BLZ945 treatment caused a brain region-specific enhancement of remyelination in the striatum/cortex, which was absent in the corpus callosum/external capsule. This beneficial effect correlated positively with microglia reduction, increased oligodendrocytes and astrogliosis. Prophylactic BLZ945 treatment prevented excessive demyelination in the corpus callosum by reducing microglia and increasing oligondendrocytes. In the external capsule oligodendrocytes were depleted but not microglia and a buildup of myelin debris and axonal damage was observed. A similar microglial dysfunction in the external capsule with an increase of myelin debris was obvious in triggering receptor expressed on myeloid cells 2 (TREM2) knock-out mice treated with cuprizone. Finally, therapeutic BLZ945 treatment did not change the disease course in experimental autoimmune encephalomyelitis mice, a peripherally driven neuroinflammation model. Taken together, our data suggest that a short-term therapeutic inhibition of the CSF-1 receptor pathway by BLZ945 in the murine cuprizone model enhances central remyelination by modulating neuroinflammation. Thus, microglia-modulating therapies could be considered clinically for promoting myelination in combination with standard-of-care treatments in MS patients.
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Affiliation(s)
- Nicolau Beckmann
- Musculoskeletal Diseases Area, Novartis Institutes for BioMedical Research, 4002, Basel, Switzerland
| | - Elisa Giorgetti
- Musculoskeletal Diseases Area, Novartis Institutes for BioMedical Research, 4002, Basel, Switzerland
| | - Anna Neuhaus
- Neuroscience, Novartis Institutes for BioMedical Research, 4002, Basel, Switzerland
| | - Stefan Zurbruegg
- Neuroscience, Novartis Institutes for BioMedical Research, 4002, Basel, Switzerland
| | - Nathalie Accart
- Musculoskeletal Diseases Area, Novartis Institutes for BioMedical Research, 4002, Basel, Switzerland
| | - Paul Smith
- Autoimmunity, Transplantation and Inflammation, Novartis Institutes for BioMedical Research, 4002, Basel, Switzerland
- Present address: Incyte, 1801 Augustine Cut-off, Wilmington, DE, 19803, USA
| | - Julien Perdoux
- Autoimmunity, Transplantation and Inflammation, Novartis Institutes for BioMedical Research, 4002, Basel, Switzerland
| | - Ludovic Perrot
- Global Scientific Operations, Novartis Institutes for BioMedical Research, 4002, Basel, Switzerland
| | - Mark Nash
- Musculoskeletal Diseases Area, Novartis Institutes for BioMedical Research, 4002, Basel, Switzerland
| | - Sandrine Desrayaud
- PK Sciences, Novartis Institutes for BioMedical Research, 4002, Basel, Switzerland
| | - Peter Wipfli
- PK Sciences, Novartis Institutes for BioMedical Research, 4002, Basel, Switzerland
| | - Wilfried Frieauff
- Preclinical Safety, Novartis Institutes for BioMedical Research, 4002, Basel, Switzerland
| | - Derya R Shimshek
- Neuroscience, Novartis Institutes for BioMedical Research, 4002, Basel, Switzerland.
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959
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Interleukin 4 modulates microglia homeostasis and attenuates the early slowly progressive phase of amyotrophic lateral sclerosis. Cell Death Dis 2018; 9:250. [PMID: 29445154 PMCID: PMC5833860 DOI: 10.1038/s41419-018-0288-4] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 12/28/2017] [Accepted: 01/04/2018] [Indexed: 12/31/2022]
Abstract
Microglia activation is a commonly pathological hallmark of neurodegenerative diseases, such as amyotrophic lateral sclerosis (ALS), a devastating disorder characterized by a selective motor neurons degeneration. Whether such activation might represent a causal event rather than a secondary epiphenomenon remains elusive. Here, we show that CNS-delivery of IL-4—via a lentiviral-mediated gene therapy strategy—skews microglia to proliferate, inducing these cells to adopt the phenotype of slowly proliferating cells. Transcriptome analysis revealed that IL-4-treated microglia express a broad number of genes normally encoded by embryonic microglia. Since embryonic microglia sustain CNS development, we then hypothesized that turning adult microglia to acquire such phenotype via IL-4 might be an efficient in vivo strategy to sustain motor neuron survival in ALS. IL-4 gene therapy in SOD1G93A mice resulted in a general amelioration of clinical outcomes during the early slowly progressive phase of the disease. However, such approach did not revert neurodegenerative processes occurring in the late and fast progressing phase of the disease.
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960
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Liu X, Wen S, Yan F, Liu K, Liu L, Wang L, Zhao S, Ji X. Salidroside provides neuroprotection by modulating microglial polarization after cerebral ischemia. J Neuroinflammation 2018; 15:39. [PMID: 29426336 PMCID: PMC5807735 DOI: 10.1186/s12974-018-1081-0] [Citation(s) in RCA: 98] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 01/26/2018] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Following stroke, microglia can be driven to the "classically activated" pro-inflammatory (M1) phenotype and the "alternatively activated" anti-inflammatory (M2) phenotype. Salidroside (SLDS) is known to inhibit inflammation and to possess protective effects in neurological diseases, but to date, the exact mechanisms involved in these processes after stroke have yet to be elucidated. The purpose of this study was to determine the effects of SLDS on neuroprotection and microglial polarization after stroke. METHODS Male adult C57/BL6 mice were subjected to focal transient cerebral ischemia followed by intravenous SLDS injection. The optimal dose was determined by evaluation of cerebral infarct volume and neurological functions. RT-PCR and immunostaining were performed to assess microglial polarization. A transwell system and a direct-contact coculture system were used to elucidate the effects of SLDS-induced microglial polarization on oligodendrocyte differentiation and neuronal survival. RESULTS SLDS significantly reduced cerebral infarction and improved neurological function after cerebral ischemia. SLDS treatment reduced the expression of M1 microglia/macrophage markers and increased the expression of M2 microglia/macrophage markers after stroke and induced primary microglia from M1 phenotype to M2 phenotype. Furthermore, SLDS treatment enhanced microglial phagocytosis and suppressed microglial-derived inflammatory cytokine release. Cocultures of oligodendrocytes and SLDS-treated M1 microglia resulted in increased oligodendrocyte differentiation. Moreover, SLDS protected neurons against oxygen glucose deprivation by promoting microglial M2 polarization. CONCLUSIONS These data demonstrate that SLDS protects against cerebral ischemia by modulating microglial polarization. An understanding of the mechanisms involved in SLDS-mediated microglial polarization may lead to new therapeutic opportunities after stroke.
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Affiliation(s)
- Xiangrong Liu
- China-America Institute of Neuroscience, Xuanwu Hospital of Capital Medical University, Beijing, 100053, People's Republic of China.,Beijing Key Laboratory of Translational Medicine for Cerebrovascular Diseases, Beijing, 100053, People's Republic of China
| | - Shaohong Wen
- China-America Institute of Neuroscience, Xuanwu Hospital of Capital Medical University, Beijing, 100053, People's Republic of China.,Beijing Key Laboratory of Translational Medicine for Cerebrovascular Diseases, Beijing, 100053, People's Republic of China
| | - Feng Yan
- Beijing Key Laboratory of Translational Medicine for Cerebrovascular Diseases, Beijing, 100053, People's Republic of China.,Cerebrovascular Diseases Research Institute, Xuanwu Hospital of Capital Medical University, Beijing, 100053, People's Republic of China
| | - Kuan Liu
- China-America Institute of Neuroscience, Xuanwu Hospital of Capital Medical University, Beijing, 100053, People's Republic of China.,Beijing Key Laboratory of Translational Medicine for Cerebrovascular Diseases, Beijing, 100053, People's Republic of China.,Cerebrovascular Diseases Research Institute, Xuanwu Hospital of Capital Medical University, Beijing, 100053, People's Republic of China
| | - Liqiang Liu
- China-America Institute of Neuroscience, Xuanwu Hospital of Capital Medical University, Beijing, 100053, People's Republic of China.,Beijing Key Laboratory of Translational Medicine for Cerebrovascular Diseases, Beijing, 100053, People's Republic of China.,Cerebrovascular Diseases Research Institute, Xuanwu Hospital of Capital Medical University, Beijing, 100053, People's Republic of China
| | - Lei Wang
- China-America Institute of Neuroscience, Xuanwu Hospital of Capital Medical University, Beijing, 100053, People's Republic of China.,Beijing Key Laboratory of Translational Medicine for Cerebrovascular Diseases, Beijing, 100053, People's Republic of China
| | - Shangfeng Zhao
- Department of Neurosurgery, Beijing Tongren Hospital, Capital University of Medical Sciences, Beijing, 100073, People's Republic of China
| | - Xunming Ji
- China-America Institute of Neuroscience, Xuanwu Hospital of Capital Medical University, Beijing, 100053, People's Republic of China. .,Beijing Key Laboratory of Translational Medicine for Cerebrovascular Diseases, Beijing, 100053, People's Republic of China. .,Department of Neurosurgery, Xuanwu Hospital, Capital University of Medical Sciences, Beijing, 100053, People's Republic of China. .,Cerebrovascular Diseases Research Institute, Xuanwu Hospital of Capital Medical University, 45 Changchun Street, Beijing, 100053, People's Republic of China.
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961
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Hirbec H, Marmai C, Duroux-Richard I, Roubert C, Esclangon A, Croze S, Lachuer J, Peyroutou R, Rassendren F. The microglial reaction signature revealed by RNAseq from individual mice. Glia 2018; 66:971-986. [PMID: 29399880 DOI: 10.1002/glia.23295] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Revised: 12/23/2017] [Accepted: 01/02/2018] [Indexed: 12/20/2022]
Abstract
Microglial cells have a double life as the immune cells of the brain in times of stress but have also specific physiological functions in homeostatic conditions. In pathological contexts, microglia undergo a phenotypic switch called "reaction" that promotes the initiation and the propagation of neuro-inflammation. Reaction is complex, molecularly heterogeneous and still poorly characterized, leading to the concept that microglial reactivity might be too diverse to be molecularly defined. However, it remains unknown whether reactive microglia from different pathological contexts share a common molecular signature. Using improved flow cytometry and RNAseq approaches we studied, with higher statistical power, the remodeling of microglia transcriptome in a mouse model of sepsis. Through bioinformatic comparison of our results with published datasets, we defined the microglial reactome as a set of genes discriminating reactive from homeostatic microglia. Ultimately, we identified a subset of 86 genes deregulated in both acute and neurodegenerative conditions. Our data provide a new comprehensive resource that includes functional analysis and specific molecular markers of microglial reaction which represent new tools for its unambiguous characterization.
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Affiliation(s)
- Hélène Hirbec
- Institute of Functional Genomics, CNRS, INSERM, University of Montpellier, Montpellier, France.,Labex ICST, Montpellier, France
| | - Camille Marmai
- Institute of Functional Genomics, CNRS, INSERM, University of Montpellier, Montpellier, France.,Labex ICST, Montpellier, France
| | | | | | | | - Séverine Croze
- ProfileXpert, Université Claude Bernard Lyon 1, Lyon, France
| | - Joël Lachuer
- ProfileXpert, Université Claude Bernard Lyon 1, Lyon, France
| | - Ronan Peyroutou
- Institute of Functional Genomics, CNRS, INSERM, University of Montpellier, Montpellier, France.,Labex ICST, Montpellier, France
| | - François Rassendren
- Institute of Functional Genomics, CNRS, INSERM, University of Montpellier, Montpellier, France.,Labex ICST, Montpellier, France
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962
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Organ-specific mechanisms linking innate and adaptive antifungal immunity. Semin Cell Dev Biol 2018; 89:78-90. [PMID: 29366628 DOI: 10.1016/j.semcdb.2018.01.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Revised: 01/09/2018] [Accepted: 01/15/2018] [Indexed: 12/24/2022]
Abstract
Fungal infections remain a significant global health problem in humans. Fungi infect millions of people worldwide and cause from acute superficial infections to life-threatening systemic disease to chronic illnesses. Trying to decipher the complex innate and adaptive immune mechanisms that protect humans from pathogenic fungi is therefore a key research goal that may lead to immune-based therapeutic strategies and improved patient outcomes. In this review, we summarize how the cells and molecules of the innate immune system activate the adaptive immune system to elicit long-term immunity to fungi. We present current knowledge and exciting new advances in the context of organ-specific immunity, outlining the tissue-specific tropisms for the major pathogenic fungi of humans, the antifungal functions of tissue-resident myeloid cells, and the adaptive immune responses required to protect specific organs from fungal challenge.
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963
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O'Loughlin E, Madore C, Lassmann H, Butovsky O. Microglial Phenotypes and Functions in Multiple Sclerosis. Cold Spring Harb Perspect Med 2018; 8:8/2/a028993. [PMID: 29419406 DOI: 10.1101/cshperspect.a028993] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Microglia are the resident immune cells that constantly survey the central nervous system. They can adapt to their environment and respond to injury or insult by altering their morphology, phenotype, and functions. It has long been debated whether microglial activation is detrimental or beneficial in multiple sclerosis (MS). Recently, the two opposing yet connected roles of microglial activation have been described with the aid of novel microglial markers, RNA profiling, and in vivo models. In this review, microglial phenotypes and functions in the context of MS will be discussed with evidence from both human pathological studies, in vitro and in vivo models. Microglial functional diversity-phagocytosis, antigen presentation, immunomodulation, support, and repair-will also be examined in detail. In addition, this review discusses the emerging evidence for microglia-related targets as biomarkers and therapeutic targets for MS.
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Affiliation(s)
- Elaine O'Loughlin
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115
| | - Charlotte Madore
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115
| | - Hans Lassmann
- Center for Brain Research, Medical University of Vienna, A-1090 Vienna, Austria
| | - Oleg Butovsky
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115.,Evergrande Center for Immunologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115
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964
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Shin JA, Kim YA, Kim HW, Kim HS, Lee KE, Kang JL, Park EM. Iron released from reactive microglia by noggin improves myelin repair in the ischemic brain. Neuropharmacology 2018; 133:202-215. [PMID: 29407213 DOI: 10.1016/j.neuropharm.2018.01.038] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Revised: 01/21/2018] [Accepted: 01/25/2018] [Indexed: 12/31/2022]
Abstract
We previously reported that the bone morphogenetic protein (BMP) antagonist, noggin, improved the repair process with an increase in the reactive microglia/macrophage population in the ischemic brain. Since BMP plays a role in intracellular iron homeostasis via the hepcidin/ferroportin axis, and iron is required for myelination, this study was aimed to determine whether noggin affected iron status and remyelination in the brain following ischemic stroke. We further examined the effect of blocking the BMP/hepcidin pathway on reactive microglia (BV2) and myelination of oligodendroglial cells (MO3.13) to define the link between microglial iron status and myelin formation. Following the noggin infusion into the ischemic brain of mice, the induction of hepcidin and ferritin protein levels decreased, and the number of myelinated axons and myelin thickness increased at 8 weeks after ischemic stroke. Noggin repressed the increase in hepcidin and ferritin levels in BV2 exposed to lipopolysaccharide (LPS) and oxygen/glucose deprivation and reperfusion (OGD/R). When MO3.13 were exposed to the conditioned media from noggin-treated BV2 (noggin CM) during reperfusion, OGD/R-induced MO3.13 cell death was reduced. Under normal conditions, noggin CM induced myelin production with an increase in ferritin levels in MO3.13, which was reversed by the iron chelator, deferoxamine. These results indicated that noggin altered the iron status in reactive microglia from the iron-storing to the iron-releasing phenotype, which contributed to myelin synthesis by providing iron. We suggest that the BMP/hepcidin pathway can be a target for the regulation of the iron status in microglia to enhance remyelination in the ischemic brain.
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Affiliation(s)
- Jin A Shin
- Department of Pharmacology, College of Medicine, Ewha Womans University, Seoul, 07985, Republic of Korea; Tissue Injury Defense Research Center, College of Medicine, Ewha Womans University, Seoul, 07985, Republic of Korea
| | - Yul A Kim
- Department of Pharmacology, College of Medicine, Ewha Womans University, Seoul, 07985, Republic of Korea
| | - Hye Won Kim
- Department of Pharmacology, College of Medicine, Ewha Womans University, Seoul, 07985, Republic of Korea; Tissue Injury Defense Research Center, College of Medicine, Ewha Womans University, Seoul, 07985, Republic of Korea
| | - Hee-Sun Kim
- Tissue Injury Defense Research Center, College of Medicine, Ewha Womans University, Seoul, 07985, Republic of Korea; Department of Molecular Medicine, College of Medicine, Ewha Womans University, Seoul, 07985, Republic of Korea
| | - Kyung-Eun Lee
- Department of Pharmacology, College of Medicine, Ewha Womans University, Seoul, 07985, Republic of Korea
| | - Jihee Lee Kang
- Tissue Injury Defense Research Center, College of Medicine, Ewha Womans University, Seoul, 07985, Republic of Korea; Department of Physiology, College of Medicine, Ewha Womans University, Seoul, 07985, Republic of Korea
| | - Eun-Mi Park
- Department of Pharmacology, College of Medicine, Ewha Womans University, Seoul, 07985, Republic of Korea; Tissue Injury Defense Research Center, College of Medicine, Ewha Womans University, Seoul, 07985, Republic of Korea.
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965
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Schetters STT, Gomez-Nicola D, Garcia-Vallejo JJ, Van Kooyk Y. Neuroinflammation: Microglia and T Cells Get Ready to Tango. Front Immunol 2018; 8:1905. [PMID: 29422891 PMCID: PMC5788906 DOI: 10.3389/fimmu.2017.01905] [Citation(s) in RCA: 231] [Impact Index Per Article: 38.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2017] [Accepted: 12/13/2017] [Indexed: 12/19/2022] Open
Abstract
In recent years, many paradigms concerning central nervous system (CNS) immunology have been challenged and shifted, including the discovery of CNS-draining lymphatic vessels, the origin and functional diversity of microglia, the impact of T cells on CNS immunological homeostasis and the role of neuroinflammation in neurodegenerative diseases. In parallel, antigen presentation outside the CNS has revealed the vital role of antigen-presenting cells in maintaining tolerance toward self-proteins, thwarting auto-immunity. Here, we review recent findings that unite these shifted paradigms of microglial functioning, antigen presentation, and CNS-directed T cell activation, focusing on common neurodegenerative diseases. It provides an important update on CNS adaptive immunity, novel targets, and a concept of the microglia T-cell equilibrium.
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Affiliation(s)
- Sjoerd T T Schetters
- Department of Molecular Cell Biology and Immunology, VU University Medical Center, Amsterdam, Netherlands
| | - Diego Gomez-Nicola
- Centre for Biological Sciences, University of Southampton, Southampton, United Kingdom
| | - Juan J Garcia-Vallejo
- Department of Molecular Cell Biology and Immunology, VU University Medical Center, Amsterdam, Netherlands
| | - Yvette Van Kooyk
- Department of Molecular Cell Biology and Immunology, VU University Medical Center, Amsterdam, Netherlands
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966
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Veremeyko T, Yung AWY, Dukhinova M, Kuznetsova IS, Pomytkin I, Lyundup A, Strekalova T, Barteneva NS, Ponomarev ED. Cyclic AMP Pathway Suppress Autoimmune Neuroinflammation by Inhibiting Functions of Encephalitogenic CD4 T Cells and Enhancing M2 Macrophage Polarization at the Site of Inflammation. Front Immunol 2018; 9:50. [PMID: 29422898 PMCID: PMC5788911 DOI: 10.3389/fimmu.2018.00050] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 01/09/2018] [Indexed: 12/15/2022] Open
Abstract
Although it has been demonstrated that cAMP pathway affect both adaptive and innate cell functions, the role of this pathway in the regulation of T-cell-mediated central nervous system (CNS) autoimmune inflammation, such as in experimental autoimmune encephalomyelitis (EAE), remains unclear. It is also unclear how cAMP pathway affects the function of CD4 T cells in vivo at the site of inflammation. We found that adenylyl cyclase activator Forskolin besides inhibition of functions autoimmune CD4 T cells also upregulated microRNA (miR)-124 in the CNS during EAE, which is associated with M2 phenotype of microglia/macrophages. Our study further established that in addition to direct influence of cAMP pathway on CD4 T cells, stimulation of this pathway promoted macrophage polarization toward M2 leading to indirect inhibition of function of T cells in the CNS. We demonstrated that Forskolin together with IL-4 or with Forskolin together with IL-4 and IFNγ effectively stimulated M2 phenotype of macrophages indicating high potency of this pathway in reprogramming of macrophage polarization in Th2- and even in Th1/Th2-mixed inflammatory conditions such as EAE. Mechanistically, Forskolin and/or IL-4 activated ERK pathway in macrophages resulting in the upregulation of M2-associated molecules miR-124, arginase (Arg)1, and Mannose receptor C-type 1 (Mrc1), which was reversed by ERK inhibitors. Administration of Forskolin after the onset of EAE substantially upregulated M2 markers Arg1, Mrc1, Fizz1, and Ym1 and inhibited M1 markers nitric oxide synthetase 2 and CD86 in the CNS during EAE resulting in decrease in macrophage/microglia activation, lymphocyte and CD4 T cell infiltration, and the recovery from the disease. Forskolin inhibited proliferation and IFNγ production by CD4 T cells in the CNS but had rather weak direct effect on proliferation of autoimmune T cells in the periphery and in vitro, suggesting prevalence of indirect effect of Forskolin on differentiation and functions of autoimmune CD4 T cells in vivo. Thus, our data indicate that Forskolin has potency to skew balance toward M2 affecting ERK pathway in macrophages and indirectly inhibit pathogenic CD4 T cells in the CNS leading to the suppression of autoimmune inflammation. These data may have also implications for future therapeutic approaches to inhibit autoimmune Th1 cells at the site of tissue inflammation.
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Affiliation(s)
- Tatyana Veremeyko
- School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Amanda W Y Yung
- School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Marina Dukhinova
- School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Inna S Kuznetsova
- School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Igor Pomytkin
- Department of Advanced Cell Technologies, Institute for Regenerative Medicine, I.M. Sechenov First Moscow State Medical University, Moscow, Russia
| | - Alexey Lyundup
- Department of Advanced Cell Technologies, Institute for Regenerative Medicine, I.M. Sechenov First Moscow State Medical University, Moscow, Russia
| | - Tatyana Strekalova
- Department of Neuroscience, Maastricht University, Maastricht, Netherlands.,Laboratory of Psychiatric Neurobiology, Institute of Molecular Medicine, I.M. Sechenov First Moscow State Medical University, Moscow, Russia
| | - Natasha S Barteneva
- Department of Pediatrics, Program in Cellular and Molecular Medicine, Children's Hospital Boston, Harvard Medical School, Boston, MA, United States.,School of Science and Technology, Nazarbayev University, Astana, Kazakhstan
| | - Eugene D Ponomarev
- School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong
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967
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Ising C, Heneka MT. Functional and structural damage of neurons by innate immune mechanisms during neurodegeneration. Cell Death Dis 2018; 9:120. [PMID: 29371603 PMCID: PMC5833757 DOI: 10.1038/s41419-017-0153-x] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 11/13/2017] [Accepted: 11/15/2017] [Indexed: 12/11/2022]
Abstract
Over the past decades, our view on neurodegenerative diseases has been mainly centered around neurons and their networks. Only recently it became evident that immunological processes arise alongside degenerating neurons, raising the question whether these represent just meaningless bystander reactions or in turn, contribute to pathogenesis and disease symptoms. When considering any effect of inflammatory events on the CNS one has to consider the site, duration and nature of immune activation. Likewise, one has to distinguish between mechanisms which directly impact the neuronal compartment and indirect mechanisms, which affect cells that are important for neuronal functioning and survival. As discussed in this review, both types of mechanisms may be present at the same time and additively or synergistically lead to neuronal demise. Inflammatory mediators released by the principle innate immune cells of the brain, microglia and astrocytes, can compromise the function and structure of neurons, thereby playing important roles in the pathogenesis of neurodegenerative diseases.
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Affiliation(s)
- Christina Ising
- German Center for Neurodegenerative Diseases (DZNE), Sigmund Freud Str. 27, 53127, Bonn, Germany
- Department of Neurodegenerative Diseases and Gerontopsychiatry/Neurology, University of Bonn Medical Center, Sigmund-Freud Str. 25, 53127, Bonn, Germany
| | - Michael T Heneka
- German Center for Neurodegenerative Diseases (DZNE), Sigmund Freud Str. 27, 53127, Bonn, Germany.
- Department of Neurodegenerative Diseases and Gerontopsychiatry/Neurology, University of Bonn Medical Center, Sigmund-Freud Str. 25, 53127, Bonn, Germany.
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968
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Mecca C, Giambanco I, Donato R, Arcuri C. Microglia and Aging: The Role of the TREM2-DAP12 and CX3CL1-CX3CR1 Axes. Int J Mol Sci 2018; 19:E318. [PMID: 29361745 PMCID: PMC5796261 DOI: 10.3390/ijms19010318] [Citation(s) in RCA: 155] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Revised: 01/17/2018] [Accepted: 01/18/2018] [Indexed: 12/21/2022] Open
Abstract
Depending on the species, microglial cells represent 5-20% of glial cells in the adult brain. As the innate immune effector of the brain, microglia are involved in several functions: regulation of inflammation, synaptic connectivity, programmed cell death, wiring and circuitry formation, phagocytosis of cell debris, and synaptic pruning and sculpting of postnatal neural circuits. Moreover, microglia contribute to some neurodevelopmental disorders such as Nasu-Hakola disease (NHD), and to aged-associated neurodegenerative diseases, such as Alzheimer's disease (AD), Parkinson's disease (PD), and others. There is evidence that human and rodent microglia may become senescent. This event determines alterations in the microglia activation status, associated with a chronic inflammation phenotype and with the loss of neuroprotective functions that lead to a greater susceptibility to the neurodegenerative diseases of aging. In the central nervous system (CNS), Triggering Receptor Expressed on Myeloid Cells 2-DNAX activation protein 12 (TREM2-DAP12) is a signaling complex expressed exclusively in microglia. As a microglial surface receptor, TREM2 interacts with DAP12 to initiate signal transduction pathways that promote microglial cell activation, phagocytosis, and microglial cell survival. Defective TREM2-DAP12 functions play a central role in the pathogenesis of several diseases. The CX3CL1 (fractalkine)-CX3CR1 signaling represents the most important communication channel between neurons and microglia. The expression of CX3CL1 in neurons and of its receptor CX3CR1 in microglia determines a specific interaction, playing fundamental roles in the regulation of the maturation and function of these cells. Here, we review the role of the TREM2-DAP12 and CX3CL1-CX3CR1 axes in aged microglia and the involvement of these pathways in physiological CNS aging and in age-associated neurodegenerative diseases.
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Affiliation(s)
- Carmen Mecca
- Department of Experimental Medicine, Perugia Medical School, University of Perugia, Piazza Lucio Severi 1, 06132 Perugia, Italy.
| | - Ileana Giambanco
- Department of Experimental Medicine, Perugia Medical School, University of Perugia, Piazza Lucio Severi 1, 06132 Perugia, Italy.
| | - Rosario Donato
- Department of Experimental Medicine, Perugia Medical School, University of Perugia, Piazza Lucio Severi 1, 06132 Perugia, Italy.
- Centro Universitario per la Ricerca sulla Genomica Funzionale, Perugia Medical School, University of Perugia, Piazza Lucio Severi 1, 06132 Perugia, Italy.
| | - Cataldo Arcuri
- Department of Experimental Medicine, Perugia Medical School, University of Perugia, Piazza Lucio Severi 1, 06132 Perugia, Italy.
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969
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Hammad A, Westacott L, Zaben M. The role of the complement system in traumatic brain injury: a review. J Neuroinflammation 2018; 15:24. [PMID: 29357880 PMCID: PMC5778697 DOI: 10.1186/s12974-018-1066-z] [Citation(s) in RCA: 99] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Accepted: 01/15/2018] [Indexed: 02/08/2023] Open
Abstract
Traumatic brain injury (TBI) is an important cause of disability and mortality in the western world. While the initial injury sustained results in damage, it is the subsequent secondary cascade that is thought to be the significant determinant of subsequent outcomes. The changes associated with the secondary injury do not become irreversible until some time after the start of the cascade. This may present a window of opportunity for therapeutic interventions aiming to improve outcomes subsequent to TBI. A prominent contributor to the secondary injury is a multifaceted inflammatory reaction. The complement system plays a notable role in this inflammatory reaction; however, it has often been overlooked in the context of TBI secondary injury. The complement system has homeostatic functions in the uninjured central nervous system (CNS), playing a part in neurodevelopment as well as having protective functions in the fully developed CNS, including protection from infection and inflammation. In the context of CNS injury, it can have a number of deleterious effects, evidence for which primarily comes not only from animal models but also, to a lesser extent, from human post-mortem studies. In stark contrast to this, complement may also promote neurogenesis and plasticity subsequent to CNS injury. This review aims to explore the role of the complement system in TBI secondary injury, by examining evidence from both clinical and animal studies. We examine whether specific complement activation pathways play more prominent roles in TBI than others. We also explore the potential role of complement in post-TBI neuroprotection and CNS repair/regeneration. Finally, we highlight the therapeutic potential of targeting the complement system in the context of TBI and point out certain areas on which future research is needed.
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Affiliation(s)
- Adnan Hammad
- School of Clinical Medicine, University of Cambridge, Cambridge, UK
| | - Laura Westacott
- Neuroscience and Mental Health Research Institute (NMHRI), School of Medicine, Cardiff University, Room 4FT 80E, 4th Floor, Heath Park, Cardiff, CF14 4XN UK
| | - Malik Zaben
- Neuroscience and Mental Health Research Institute (NMHRI), School of Medicine, Cardiff University, Room 4FT 80E, 4th Floor, Heath Park, Cardiff, CF14 4XN UK
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970
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Zeng HL, Shi JM. The role of microglia in the progression of glaucomatous neurodegeneration- a review. Int J Ophthalmol 2018; 11:143-149. [PMID: 29376003 DOI: 10.18240/ijo.2018.01.22] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2017] [Accepted: 08/28/2017] [Indexed: 12/11/2022] Open
Abstract
Glaucoma is a serious leading cause of irreversible blindness worldwide. Reducing intraocular pressure (IOP) does not always stop glaucomatous neurodegeneration and the optic nerve may continue to be damaged in the normal IOP. Microglial activity has been recognized to play essential roles in pathogenesis of the central nervous system (CNS) as well as retinal ganglion cell (RGC) survival. The relationship between the neurodegeneration and the microglia cells in glaucoma is very complicated and still remains unclear. In the present review, we summarize the recent studies of mechanisms of microglia in glaucoma neurodegeneration, which might provide new ways to treat glaucoma.
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Affiliation(s)
- Hui-Lan Zeng
- Department of Ophthalmology, the Second Xiangya Hospital, Central South University, Changsha 410011, Hunan Province, China
| | - Jing-Ming Shi
- Department of Ophthalmology, the Second Xiangya Hospital, Central South University, Changsha 410011, Hunan Province, China
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971
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Microglia and Neonatal Brain Injury. Neuroscience 2018; 405:68-76. [PMID: 29352997 DOI: 10.1016/j.neuroscience.2018.01.023] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 12/21/2017] [Accepted: 01/09/2018] [Indexed: 12/16/2022]
Abstract
Microglial cells are now recognized as the "gate-keepers" of healthy brain microenvironment with their disrupted functions adversely affecting neurovascular integrity, neuronal homeostasis, and network connectivity. The perception that these cells are purely toxic under neurodegenerative conditions has been challenged by a continuously increasing understanding of their complexity, the existence of a broad array of microglial phenotypes, and their ability to rapidly change in a context-dependent manner to attenuate or exacerbate injuries of different nature. Recent studies have demonstrated that microglial cells exert crucial physiological functions during embryonic and postnatal brain development, some of these functions being unique to particular stages of development, and extending far beyond sensing dangerous signals and serving as antigen presenting cells. In this focused review we cover the roles of microglial cells in regulating embryonic vasculogenesis, neurogenesis, and establishing network connectivity during postnatal brain development. We further discuss context-dependent microglial contribution to neonatal brain injuries associated with prenatal and postnatal infection and inflammation, in relation to neurodevelopmental disorders, as well as perinatal hypoxia-ischemia and arterial focal stroke. We also emphasize microglial phenotypic diversity, notably at the ultrastructural level, and their sex-dependent influence on the pathophysiology of neurodevelopmental disorders.
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972
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Laquinimod ameliorates excitotoxic damage by regulating glutamate re-uptake. J Neuroinflammation 2018; 15:5. [PMID: 29304807 PMCID: PMC5756343 DOI: 10.1186/s12974-017-1048-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 12/21/2017] [Indexed: 11/10/2022] Open
Abstract
Background Laquinimod is an immunomodulatory drug under clinical investigation for the treatment of the progressive form of multiple sclerosis (MS) with both anti-inflammatory and neuroprotective effects. Excitotoxicity, a prominent pathophysiological feature of MS and of its animal model, experimental autoimmune encephalomyelitis (EAE), involves glutamate transporter (GluT) dysfunction in glial cells. The aim of this study was to assess whether laquinimod might exert direct neuroprotective effects by interfering with the mechanisms of excitotoxicity linked to GluT function impairments in EAE. Methods Osmotic minipumps allowing continuous intracerebroventricular (icv) infusion of laquinimod for 4 weeks were implanted into C57BL/6 mice before EAE induction. EAE cerebella were taken to perform western blot and qPCR experiments. For ex vivo experiments, EAE cerebellar slices were incubated with laquinimod before performing electrophysiology, western blot, and qPCR. Results In vivo treatment with laquinimod attenuated EAE clinical score at the peak of the disease, without remarkable effects on inflammatory markers. In vitro application of laquinimod to EAE cerebellar slices prevented EAE-linked glutamatergic alterations without mitigating astrogliosis and inflammation. Moreover, such treatment induced an increase of Slcla3 mRNA coding for the glial glutamate–aspartate transporter (GLAST) without affecting the protein content. Concomitantly, laquinimod significantly increased the levels of the glial glutamate transporter 1 (GLT-1) protein and pharmacological blockade of GLT-1 function fully abolished laquinimod anti-excitotoxic effect. Conclusions Overall, our results suggest that laquinimod protects against glutamate excitotoxicity of the cerebellum of EAE mice by bursting the expression of glial glutamate transporters, independently of its anti-inflammatory effects.
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973
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Wang X, Zhao W, Ransohoff RM, Zhou L. Infiltrating macrophages are broadly activated at the early stage to support acute skeletal muscle injury repair. J Neuroimmunol 2018; 317:55-66. [PMID: 29325905 DOI: 10.1016/j.jneuroim.2018.01.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 01/03/2018] [Accepted: 01/04/2018] [Indexed: 12/16/2022]
Abstract
Acute skeletal muscle injury repair requires an adequate inflammatory response predominated by macrophage infiltration. We studied the activation of infiltrating macrophages by analyzing the expression of M1/M2 signature genes. Most of the intramuscular macrophages were Ly6Chi at day 1 after BaCl2 injection, while many were Ly6Clo at day 3. Ly6Chi macrophages at day 1 expressed a high level of both M1 and M2 genes, and the Ly6Chi and Ly6Clo macrophages at day 3 expressed a similar level of many M1/M2 genes. Infiltrating macrophages are broadly activated rather than polarized at the early stage to support acute skeletal muscle injury repair.
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Affiliation(s)
- Xingyu Wang
- Department of Neurology & Neurotherapeutics, UT Southwestern Medical Center, Dallas, TX 75390, United States
| | - Wanming Zhao
- Department of Human Oncology, Memorial Sloan Kattering Cancer Center, New York, NY 10065, United States
| | | | - Lan Zhou
- Department of Neurology & Neurotherapeutics, UT Southwestern Medical Center, Dallas, TX 75390, United States.
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974
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Maduna T, Audouard E, Dembélé D, Mouzaoui N, Reiss D, Massotte D, Gaveriaux-Ruff C. Microglia Express Mu Opioid Receptor: Insights From Transcriptomics and Fluorescent Reporter Mice. Front Psychiatry 2018; 9:726. [PMID: 30662412 PMCID: PMC6328486 DOI: 10.3389/fpsyt.2018.00726] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 12/10/2018] [Indexed: 12/18/2022] Open
Abstract
Background: Microglia activation contributes to chronic pain and to the adverse effects of opiate use such as analgesic tolerance and opioid-induced hyperalgesia. Both mu opioid receptor (MOR) encoded by Oprm1/OPRM1 gene and toll like receptor 4 (TLR4) have been reported to mediate these morphine effects and a current question is whether microglia express the Oprm1 transcript and MOR protein. The aim of this study was to characterize Oprm1-MOR expression in naive murine and human microglia, combining transcriptomics datasets previously published by other groups with our own imaging study using the Cx3cr1-eGFP-MOR-mCherry reporter mouse line. Methods: We analyzed microglial Oprm1/OPRM1 expression obtained from transcriptomics datasets, focusing on ex vivo studies from adult wild-type animals and adult post-mortem human cerebral cortex. Oprm1, as well as co-regulated gene sets were examined. The expression of MOR in microglia was also investigated using our novel fluorescent Cx3cr1-eGFP-MOR-mcherry reporter mouse line. We determined whether CX3cR1-eGFP positive microglial cells expressed MOR-mCherry protein by imaging various brain areas including the Frontal Cortex, Nucleus Accumbens, Ventral Tegmental Area, Central Amygdala, and Periaqueductal Gray matter, as well as spinal cord. Results: Oprm1 expression was found in all 12 microglia datasets from mouse whole brain, in 7 out of 8 from cerebral cortex, 3 out of 4 from hippocampus, 1 out of 1 from striatum, and 4 out of 5 from mouse or rat spinal cord. OPRM1 was expressed in 16 out of 17 microglia transcriptomes from human cerebral cortex. In Cx3cr1-eGFP-MOR-mCherry mice, the percentage of MOR-positive microglial cells ranged between 35.4 and 51.6% in the different brain areas, and between 36.8 and 42.4% in the spinal cord. Conclusion: The comparative analysis of the microglia transcriptomes indicates that Oprm1/OPRM1 transcripts are expressed in microglia. The investigation of Cx3cr1-eGFP-MOR-mCherry mice also shows microglial expression of MOR proteinin the brain and spine. These results corroborate functional studies showing the actions of MOR agonists on microglia and suppression of these effects by MOR-selective antagonists or MOR knockdown.
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Affiliation(s)
- Tando Maduna
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France.,Université de Strasbourg, Illkirch, France.,Centre National de la Recherche Scientifique, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, Illkirch, France
| | - Emilie Audouard
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France.,Université de Strasbourg, Illkirch, France.,Centre National de la Recherche Scientifique, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, Illkirch, France
| | - Doulaye Dembélé
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France.,Université de Strasbourg, Illkirch, France.,Centre National de la Recherche Scientifique, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, Illkirch, France
| | - Nejma Mouzaoui
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France.,Université de Strasbourg, Illkirch, France.,Centre National de la Recherche Scientifique, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, Illkirch, France.,Ecole Supérieure de Biotechnologie de Strasbourg, Illkirch, France
| | - David Reiss
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France.,Université de Strasbourg, Illkirch, France.,Centre National de la Recherche Scientifique, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, Illkirch, France
| | - Dominique Massotte
- CNRS UPR3212, Institut des Neurosciences Cellulaires et Intégratives, Centre National de la Recherche Scientifique, Université de Strasbourg, Strasbourg, France
| | - Claire Gaveriaux-Ruff
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France.,Université de Strasbourg, Illkirch, France.,Centre National de la Recherche Scientifique, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, Illkirch, France.,Ecole Supérieure de Biotechnologie de Strasbourg, Illkirch, France
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975
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Evidence of microglial activation following exposure to serum from first-onset drug-naïve schizophrenia patients. Brain Behav Immun 2018; 67:364-373. [PMID: 28988033 DOI: 10.1016/j.bbi.2017.10.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Revised: 09/18/2017] [Accepted: 10/02/2017] [Indexed: 01/29/2023] Open
Abstract
Abnormal activation of brain microglial cells is widely implicated in the pathogenesis of schizophrenia. Previously the pathophysiology of microglial activation was considered to be intrinsic to the central nervous system. We hypothesised that due to their perivascular localization, microglia can also be activated by factors present in circulating blood. Through application of high-content functional screening, we show that peripheral blood serum from first-onset drug-naïve schizophrenia patients is sufficient to provoke microglial cell signalling network responses in vitro which are indicative of proinflammatory activation. We further explore the composition of the serum for the presence of analytes, with the potential to activate microglia, and the utility of the resultant microglial cellular phenotype for novel drug discovery.
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976
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Caponegro MD, Miyauchi JT, Tsirka SE. Contributions of immune cell populations in the maintenance, progression, and therapeutic modalities of glioma. AIMS ALLERGY AND IMMUNOLOGY 2018; 2:24-44. [PMID: 32914058 PMCID: PMC7480949 DOI: 10.3934/allergy.2018.1.24] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Immunotherapies are becoming a promising strategy for malignant disease. Selectively directing host immune responses to target cancerous tissue is a milestone of human health care. The roles of the innate and adaptive immune systems in both cancer progression and elimination are now being realized. Defining the immune cell environment and identifying the contributions of each sub-population of these cells has lead to an understanding of the immunotherapeutic processes, and demonstrated the potential of the immune system to drive cancer shrinkage and sustained immunity against disease. Poorly treated diseases, such as high-grade glioma, suffer from lack of therapeutic efficacy and rapid progression. Immunotherapeutic success in other solid malignancies, such as melanoma, now provides the principals for which this treatment paradigm can be adapted for primary brain cancers. The central nervous system is complex, and relative contributions of immune sub-populations to high grade glioma progression are not fully characterized. Here, we summarize recent research in both animal and humans which add to the knowledge base of how innate and adaptive immune cells contribute to glioma progression, and outline work which has demonstrated their potential to elicit anti-tumorigenic responses. Additionally, we highlight Neuropilin 1, a cell surface receptor protein, describe its signaling functions in the context of immunity, and point to its potential to slow glioma progression.
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Affiliation(s)
- Michael D Caponegro
- Department of Pharmacological Sciences, BioMedical Sciences, Stony Brook University, Stony Brook, NY, USA
| | - Jeremy Tetsuo Miyauchi
- Department of Pharmacological Sciences, BioMedical Sciences, Stony Brook University, Stony Brook, NY, USA
| | - Stella E Tsirka
- Department of Pharmacological Sciences, BioMedical Sciences, Stony Brook University, Stony Brook, NY, USA
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977
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Usage of Multiparameter Flow Cytometry to Study Microglia and Macrophage Heterogeneity in the Central Nervous System During Neuroinflammation and Neurodegeneration. Methods Mol Biol 2018; 1745:167-177. [PMID: 29476469 DOI: 10.1007/978-1-4939-7680-5_10] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The resident macrophages of the central nervous system (CNS), also known as microglia, and blood-derived macrophages play an important role in the functional activity of the normal CNS, as well as in the development of neuroinflammation during various neurodegenerative disorders. Microglia and macrophages represent heterogeneous populations, which can modulate CNS environment and have different effects on neuronal regeneration. In this chapter, the main features of microglial and macrophage subsets and current methods for investigation of their heterogeneity will be discussed.
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978
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Fakhoury M. Microglia and Astrocytes in Alzheimer's Disease: Implications for Therapy. Curr Neuropharmacol 2018; 16:508-518. [PMID: 28730967 PMCID: PMC5997862 DOI: 10.2174/1570159x15666170720095240] [Citation(s) in RCA: 296] [Impact Index Per Article: 49.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2017] [Revised: 06/21/2017] [Accepted: 07/19/2017] [Indexed: 01/23/2023] Open
Abstract
BACKGROUND Alzheimer's disease (AD) is a complex neurodegenerative disorder characterized by the progressive loss of neurons, which typically leads to severe impairments in cognitive functions including memory and learning. Key pathological features of this disease include the deposition of highly insoluble amyloid β peptides and the formation of neurofibrillary tangles (NFTs) in the brain. Mounting evidence also implicates sustained glial-mediated inflammation as a major contributor of the neurodegenerative processes and cognitive deficits observed in AD. METHODS This paper provides an overview of findings from both human and animal studies investigating the role of microglia and astrocytes in AD, and discusses potential avenues for therapeutic intervention. RESULTS Glial-mediated inflammation is a 'double-edged sword', performing both detrimental and beneficial functions in AD. Despite tremendous effort in elucidating the molecular and cellular mechanisms underlying AD pathology, to date, there is no treatment that could prevent or cure this disease. Current treatments are only useful in slowing down the progression of AD and helping patients manage some of their behavioral and cognitive symptoms. CONCLUSION A better understanding of the role of microglia and astrocytes in the regulation of AD pathology is needed as this could pave the way for new therapeutic strategies.
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Affiliation(s)
- Marc Fakhoury
- Department of Neurosciences, Faculty of Medicine, Université de Montréal, Montreal, Quebec, Canada
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979
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Haley MJ, Brough D, Quintin J, Allan SM. Microglial Priming as Trained Immunity in the Brain. Neuroscience 2017; 405:47-54. [PMID: 29292078 DOI: 10.1016/j.neuroscience.2017.12.039] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 11/09/2017] [Accepted: 12/20/2017] [Indexed: 12/22/2022]
Abstract
In this review we discuss the possibility that the phenomenon of microglial priming can be explained by the mechanisms that underlie trained immunity. The latter involves the enhancement of inflammatory responses by epigenetic mechanisms that are mobilized after first exposure to an inflammatory stimulus. These mechanisms include long-lasting histone modifications, including H3K4me1 deposition at latent enhancer regions. Although such changes may be beneficial in peripheral infectious disease, in the context of microglial priming they may drive increased microglia reactivity that is damaging in diseases of brain aging.
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Affiliation(s)
- Michael J Haley
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Manchester M13 9PT, UK
| | - David Brough
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Manchester M13 9PT, UK.
| | - Jessica Quintin
- Immunology of Fungal Infections Group, Department of Mycology, Institut Pasteur, 25 rue du Docteur Roux, Paris, France
| | - Stuart M Allan
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Manchester M13 9PT, UK
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980
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Correani V, Di Francesco L, Mignogna G, Fabrizi C, Leone S, Giorgi A, Passeri A, Casata R, Fumagalli L, Maras B, Schininà ME. Plasma Membrane Protein Profiling in Beta-Amyloid-Treated Microglia Cell Line. Proteomics 2017; 17. [PMID: 28815942 DOI: 10.1002/pmic.201600439] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Revised: 08/01/2017] [Indexed: 01/13/2023]
Abstract
In the responsiveness of microglia to toxic stimuli, plasma membrane proteins play a key role. In this study we treated with a synthetic beta amyloid peptide murine microglial cells metabolically differently labelled with stable isotope amino acids (SILAC). The plasma membrane was selectively enriched by a multi-stage aqueous two-phase partition system. We were able to identify by 1D-LC-MS/MS analyses 1577 proteins, most of them are plasma membrane proteins according to the Gene Ontology annotation. An unchanged level of amyloid receptors in this data set suggests that microglia preserve their responsiveness capability to the environment even after 24-h challenge with amyloid peptides. On the other hand, 14 proteins were observed to change their plasma membrane abundance to a statistically significant extent. Among these, we proposed as reliable biomarkers of the inflammatory microglia phenotype in AD damaged tissues MAP/microtubule affinity-regulating kinase 3 (MARK3), Interferon-induced transmembrane protein 3 (IFITM3), Annexins A5 and A7 (ANXA5, ANXA7) and Neuropilin-1 (NRP1), all proteins known to be involved in the inflammation processes and in microtubule network assembly rate.
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Affiliation(s)
- Virginia Correani
- Dipartimento di Scienze Biochimiche, Sapienza Università di Roma, Rome, Italy
| | - Laura Di Francesco
- Dipartimento di Scienze Biochimiche, Sapienza Università di Roma, Rome, Italy
| | - Giuseppina Mignogna
- Dipartimento di Scienze Biochimiche, Sapienza Università di Roma, Rome, Italy
| | - Cinzia Fabrizi
- Dipartimento di Scienze Anatomiche Istologiche, Medico-Legali e dell'Apparato Locomotore, Sapienza Università di Roma, Rome, Italy
| | - Stefano Leone
- Dipartimento di Scienze, Università Roma Tre, Rome, Italy
| | - Alessandra Giorgi
- Dipartimento di Scienze Biochimiche, Sapienza Università di Roma, Rome, Italy
| | - Alessia Passeri
- Dipartimento di Scienze Biochimiche, Sapienza Università di Roma, Rome, Italy
| | - Roberto Casata
- Dipartimento di Scienze Biochimiche, Sapienza Università di Roma, Rome, Italy
| | - Lorenzo Fumagalli
- Dipartimento di Scienze Anatomiche Istologiche, Medico-Legali e dell'Apparato Locomotore, Sapienza Università di Roma, Rome, Italy
| | - Bruno Maras
- Dipartimento di Scienze Biochimiche, Sapienza Università di Roma, Rome, Italy
| | - M Eugenia Schininà
- Dipartimento di Scienze Biochimiche, Sapienza Università di Roma, Rome, Italy
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981
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Adams KL, Gallo V. The diversity and disparity of the glial scar. Nat Neurosci 2017; 21:9-15. [PMID: 29269757 DOI: 10.1038/s41593-017-0033-9] [Citation(s) in RCA: 245] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 10/17/2017] [Indexed: 01/02/2023]
Abstract
Injury or disease to the CNS results in multifaceted cellular and molecular responses. One such response, the glial scar, is a structural formation of reactive glia around an area of severe tissue damage. While traditionally viewed as a barrier to axon regeneration, beneficial functions of the glial scar have also been recently identified. In this Perspective, we discuss the divergent roles of the glial scar during CNS regeneration and explore the possibility that these disparities are due to functional heterogeneity within the cells of the glial scar-specifically, astrocytes, NG2 glia and microglia.
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Affiliation(s)
- Katrina L Adams
- Center for Neuroscience Research, Children's National Medical Center, Washington, DC, USA.
| | - Vittorio Gallo
- Center for Neuroscience Research, Children's National Medical Center, Washington, DC, USA.
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982
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Plastira I, Bernhart E, Goeritzer M, DeVaney T, Reicher H, Hammer A, Lohberger B, Wintersperger A, Zucol B, Graier WF, Kratky D, Malle E, Sattler W. Lysophosphatidic acid via LPA-receptor 5/protein kinase D-dependent pathways induces a motile and pro-inflammatory microglial phenotype. J Neuroinflammation 2017; 14:253. [PMID: 29258556 PMCID: PMC5735906 DOI: 10.1186/s12974-017-1024-1] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 12/06/2017] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Extracellular lysophosphatidic acid (LPA) species transmit signals via six different G protein-coupled receptors (LPAR1-6) and are indispensible for brain development and function of the nervous system. However, under neuroinflammatory conditions or brain damage, LPA levels increase, thereby inducing signaling cascades that counteract brain function. We describe a critical role for 1-oleyl-2-hydroxy-sn-glycero-3-phosphate (termed "LPA" throughout our study) in mediating a motile and pro-inflammatory microglial phenotype via LPAR5 that couples to protein kinase D (PKD)-mediated pathways. METHODS Using the xCELLigence system and time-lapse microscopy, we investigated the migrational response of microglial cells. Different M1 and M2 markers were analyzed by confocal microscopy, flow cytometry, and immunoblotting. Using qPCR and ELISA, we studied the expression of migratory genes and quantitated the secretion of pro-inflammatory cytokines and chemokines, respectively. Different transcription factors that promote the regulation of pro-inflammatory genes were analyzed by western blot. Reactive oxygen species (ROS) and nitric oxide (NO) production, phagocytosis, and microglial cytotoxicity were determined using commercially available assay kits. RESULTS LPA induces MAPK family and AKT activation and pro-inflammatory transcription factors' phosphorylation (NF-κB, c-Jun, STAT1, and STAT3) that were inhibited by both LPAR5 and PKD family antagonists. LPA increases migratory capacity, induces secretion of pro-inflammatory cytokines and chemokines and expression of M1 markers, enhances production of ROS and NO by microglia, and augments cytotoxicity of microglial cell-conditioned medium towards neurons. The PKD family inhibitor blunted all of these effects. We propose that interference with this signaling axis could aid in the development of new therapeutic approaches to control neuroinflammation under conditions of overshooting LPA production. CONCLUSIONS In the present study, we show that inflammatory LPA levels increased the migratory response of microglia and promoted a pro-inflammatory phenotype via the LPAR5/PKD axis. Interference with this signaling axis reduced microglial migration, blunted microglial cytotoxicity, and abrogated the expression and secretion of pro-inflammatory mediators.
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Affiliation(s)
- I. Plastira
- 0000 0000 8988 2476grid.11598.34Institute of Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstrasse 6/6, 8010 Graz, Austria
| | - E. Bernhart
- 0000 0000 8988 2476grid.11598.34Institute of Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstrasse 6/6, 8010 Graz, Austria
| | - M. Goeritzer
- 0000 0000 8988 2476grid.11598.34Institute of Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstrasse 6/6, 8010 Graz, Austria ,grid.452216.6BioTechMed-Graz, Graz, Austria
| | - T. DeVaney
- 0000 0000 8988 2476grid.11598.34Institute of Biophysics, Medical University of Graz, Graz, Austria
| | - H. Reicher
- 0000 0000 8988 2476grid.11598.34Institute of Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstrasse 6/6, 8010 Graz, Austria
| | - A. Hammer
- 0000 0000 8988 2476grid.11598.34Institute of Cell Biology, Histology and Embryology, Medical University of Graz, Graz, Austria
| | - B. Lohberger
- 0000 0000 8988 2476grid.11598.34Department of Orthopedic Surgery, Medical University of Graz, Graz, Austria
| | - A. Wintersperger
- 0000 0000 8988 2476grid.11598.34Institute of Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstrasse 6/6, 8010 Graz, Austria
| | - B. Zucol
- 0000 0000 8988 2476grid.11598.34Institute of Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstrasse 6/6, 8010 Graz, Austria
| | - W. F. Graier
- 0000 0000 8988 2476grid.11598.34Institute of Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstrasse 6/6, 8010 Graz, Austria ,grid.452216.6BioTechMed-Graz, Graz, Austria
| | - D. Kratky
- 0000 0000 8988 2476grid.11598.34Institute of Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstrasse 6/6, 8010 Graz, Austria ,grid.452216.6BioTechMed-Graz, Graz, Austria
| | - E. Malle
- 0000 0000 8988 2476grid.11598.34Institute of Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstrasse 6/6, 8010 Graz, Austria
| | - W. Sattler
- 0000 0000 8988 2476grid.11598.34Institute of Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstrasse 6/6, 8010 Graz, Austria ,grid.452216.6BioTechMed-Graz, Graz, Austria
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983
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Islam A, Choudhury ME, Kigami Y, Utsunomiya R, Matsumoto S, Watanabe H, Kumon Y, Kunieda T, Yano H, Tanaka J. Sustained anti-inflammatory effects of TGF-β1 on microglia/macrophages. Biochim Biophys Acta Mol Basis Dis 2017; 1864:721-734. [PMID: 29269050 DOI: 10.1016/j.bbadis.2017.12.022] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 12/07/2017] [Accepted: 12/13/2017] [Indexed: 12/26/2022]
Abstract
Ischemic brain injuries caused release of damage-associated molecular patterns (DAMPs) that activate microglia/macrophages (MG/MPs) by binding to Toll-like receptors. Using middle cerebral artery transiently occluded rats, we confirmed that MG/MPs expressed inducible nitric oxide synthase (iNOS) on 3days after reperfusion (dpr) in ischemic rat brain. iNOS expression almost disappeared on 7dpr when transforming growth factor-β1 (TGF-β1) expression was robustly increased. After transient incubation with TGF-β1 for 24h, rat primary microglial cells were incubated with lipopolysaccharide (LPS) and released NO level was measured. The NO release was persistently suppressed even 72h after removal of TGF-β1. The sustained TGF-β1 effects were not attributable to microglia-derived endogenous TGF-β1, as revealed by TGF-β1 knockdown and in vitro quantification studies. Then, boiled supernatants prepared from ischemic brain tissues showed the similar sustained inhibitory effects on LPS-treated microglial cells that were prevented by the TGF-β1 receptor-selective blocker SB525334. After incubation with TGF-β1 for 24h and its subsequent removal, LPS-induced phosphorylation of IκB kinases (IKKs), IκB degradation, and NFκB nuclear translocation were inhibited in a sustained manner. SB525334 abolished all these effects of TGF-β1. In consistent with the in vitro results, phosphorylated IKK-immunoreactivity was abundant in MG/MPs in ischemic brain lesion on 3dpr, whereas it was almost disappeared on 7dpr. The findings suggest that abundantly produced TGF-β1 in ischemic brain displays sustained anti-inflammatory effects on microglial cells by persistently inhibiting endogenous Toll-like receptor ligand-induced IκB degradation.
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Affiliation(s)
- Afsana Islam
- Department of Molecular and Cellular Physiology, Graduate School of Medicine, Ehime University, Japan
| | | | - Yuka Kigami
- Department of Molecular and Cellular Physiology, Graduate School of Medicine, Ehime University, Japan
| | - Ryo Utsunomiya
- Department of Molecular and Cellular Physiology, Graduate School of Medicine, Ehime University, Japan
| | - Shirabe Matsumoto
- Department of Neurosurgery, Graduate School of Medicine, Ehime University, Japan
| | - Hideaki Watanabe
- Department of Neurosurgery, Graduate School of Medicine, Ehime University, Japan
| | - Yoshiaki Kumon
- Department of Regeneration of Community Medicine, Graduate School of Medicine, Ehime University, Japan
| | - Takeharu Kunieda
- Department of Neurosurgery, Graduate School of Medicine, Ehime University, Japan
| | - Hajime Yano
- Department of Molecular and Cellular Physiology, Graduate School of Medicine, Ehime University, Japan
| | - Junya Tanaka
- Department of Molecular and Cellular Physiology, Graduate School of Medicine, Ehime University, Japan.
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984
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Mishra PS, Vijayalakshmi K, Nalini A, Sathyaprabha TN, Kramer BW, Alladi PA, Raju TR. Etiogenic factors present in the cerebrospinal fluid from amyotrophic lateral sclerosis patients induce predominantly pro-inflammatory responses in microglia. J Neuroinflammation 2017; 14:251. [PMID: 29246232 PMCID: PMC5732516 DOI: 10.1186/s12974-017-1028-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Accepted: 12/08/2017] [Indexed: 11/18/2022] Open
Abstract
Background Microglial cell-associated neuroinflammation is considered as a potential contributor to the pathophysiology of sporadic amyotrophic lateral sclerosis. However, the specific role of microglia in the disease pathogenesis remains to be elucidated. Methods We studied the activation profiles of the microglial cultures exposed to the cerebrospinal fluid from these patients which recapitulates the neurodegeneration seen in sporadic amyotrophic lateral sclerosis. This was done by investigating the morphological and functional changes including the expression levels of prostaglandin E2 (PGE2), cyclooxygenase-2 (COX-2), TNF-α, IL-6, IFN-γ, IL-10, inducible nitric oxide synthase (iNOS), arginase, and trophic factors. We also studied the effect of chitotriosidase, the inflammatory protein found upregulated in the cerebrospinal fluid from amyotrophic lateral sclerosis patients, on these cultures. Results We report that the cerebrospinal fluid from amyotrophic lateral sclerosis patients could induce an early and potent response in the form of microglial activation, skewed primarily towards a pro-inflammatory profile. It was seen in the form of upregulation of the pro-inflammatory cytokines and factors including IL-6, TNF-α, iNOS, COX-2, and PGE2. Concomitantly, a downregulation of beneficial trophic factors and anti-inflammatory markers including VEGF, glial cell line-derived neurotrophic factor, and IFN-γ was seen. In addition, chitotriosidase-1 appeared to act specifically via the microglial cells. Conclusion Our findings demonstrate that the cerebrospinal fluid from amyotrophic lateral sclerosis patients holds enough cues to induce microglial inflammatory processes as an early event, which may contribute to the neurodegeneration seen in the sporadic amyotrophic lateral sclerosis. These findings highlight the dynamic role of microglial cells in the pathogenesis of the disease, thus suggesting the need for a multidimensional and temporally guarded therapeutic approach targeting the inflammatory pathways for its treatment. Electronic supplementary material The online version of this article (10.1186/s12974-017-1028-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Pooja-Shree Mishra
- Department of Neurophysiology, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, 560029, India.,Present Address: Centre de Recherche CERVO, Quebec, QC, G1J 2G3, Canada
| | - K Vijayalakshmi
- Department of Neurophysiology, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, 560029, India
| | - A Nalini
- Department of Neurology, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, 560029, India
| | - T N Sathyaprabha
- Department of Neurophysiology, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, 560029, India
| | - B W Kramer
- School of Mental Health and Neuroscience, Maastricht Universitair Medisch Centrum, Maastricht, Limburg, Netherlands
| | - Phalguni Anand Alladi
- Department of Neurophysiology, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, 560029, India
| | - T R Raju
- Department of Neurophysiology, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, 560029, India.
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985
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Clayton KA, Van Enoo AA, Ikezu T. Alzheimer's Disease: The Role of Microglia in Brain Homeostasis and Proteopathy. Front Neurosci 2017; 11:680. [PMID: 29311768 PMCID: PMC5733046 DOI: 10.3389/fnins.2017.00680] [Citation(s) in RCA: 95] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2017] [Accepted: 11/21/2017] [Indexed: 01/15/2023] Open
Abstract
Brain aging is central to late-onset Alzheimer's disease (LOAD), although the mechanisms by which it occurs at protein or cellular levels are not fully understood. Alzheimer's disease is the most common proteopathy and is characterized by two unique pathologies: senile plaques and neurofibrillary tangles, the former accumulating earlier than the latter. Aging alters the proteostasis of amyloid-β peptides and microtubule-associated protein tau, which are regulated in both autonomous and non-autonomous manners. Microglia, the resident phagocytes of the central nervous system, play a major role in the non-autonomous clearance of protein aggregates. Their function is significantly altered by aging and neurodegeneration. This is genetically supported by the association of microglia-specific genes, TREM2 and CD33, and late onset Alzheimer's disease. Here, we propose that the functional characterization of microglia, and their contribution to proteopathy, will lead to a new therapeutic direction in Alzheimer's disease research.
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Affiliation(s)
- Kevin A Clayton
- Department of Pharmacology and Experimental Therapeutics, Medical School, Boston University, Boston, MA, United States
| | - Alicia A Van Enoo
- Department of Pharmacology and Experimental Therapeutics, Medical School, Boston University, Boston, MA, United States
| | - Tsuneya Ikezu
- Department of Pharmacology and Experimental Therapeutics, Medical School, Boston University, Boston, MA, United States.,Department of Neurology, Medical School, Boston University, Boston, MA, United States
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986
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Lannes N, Eppler E, Etemad S, Yotovski P, Filgueira L. Microglia at center stage: a comprehensive review about the versatile and unique residential macrophages of the central nervous system. Oncotarget 2017; 8:114393-114413. [PMID: 29371994 PMCID: PMC5768411 DOI: 10.18632/oncotarget.23106] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 11/15/2017] [Indexed: 02/07/2023] Open
Abstract
Microglia cells are the unique residential macrophages of the central nervous system (CNS). They have a special origin, as they derive from the embryonic yolk sac and enter the developing CNS at a very early stage. They play an important role during CNS development and adult homeostasis. They have a major contribution to adult neurogenesis and neuroinflammation. Thus, they participate in the pathogenesis of neurodegenerative diseases and contribute to aging. They play an important role in sustaining and breaking the blood-brain barrier. As innate immune cells, they contribute substantially to the immune response against infectious agents affecting the CNS. They play also a major role in the growth of tumours of the CNS. Microglia are consequently the key cell population linking the nervous and the immune system. This review covers all different aspects of microglia biology and pathology in a comprehensive way.
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Affiliation(s)
- Nils Lannes
- Albert Gockel, Anatomy, Department of Medicine, University of Fribourg, CH-1700 Fribourg, Switzerland
| | - Elisabeth Eppler
- Pestalozzistrasse Zo, Department of BioMedicine, University of Basel, CH-4056 Basel, Switzerland
| | - Samar Etemad
- Building 71/218 RBWH Herston, Centre for Clinical Research, The University of Queensland, QLD 4029 Brisbane, Australia
| | - Peter Yotovski
- Albert Gockel, Anatomy, Department of Medicine, University of Fribourg, CH-1700 Fribourg, Switzerland
| | - Luis Filgueira
- Albert Gockel, Anatomy, Department of Medicine, University of Fribourg, CH-1700 Fribourg, Switzerland
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987
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Song JJ, Oh SM, Kwon OC, Wulansari N, Lee HS, Chang MY, Lee E, Sun W, Lee SE, Chang S, An H, Lee CJ, Lee SH. Cografting astrocytes improves cell therapeutic outcomes in a Parkinson's disease model. J Clin Invest 2017; 128:463-482. [PMID: 29227284 DOI: 10.1172/jci93924] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 10/31/2017] [Indexed: 12/20/2022] Open
Abstract
Transplantation of neural progenitor cells (NPCs) is a potential therapy for treating neurodegenerative disorders, but this approach has faced many challenges and limited success, primarily because of inhospitable host brain environments that interfere with enriched neuron engraftment and function. Astrocytes play neurotrophic roles in the developing and adult brain, making them potential candidates for helping with modification of hostile brain environments. In this study, we examined whether astrocytic function could be utilized to overcome the current limitations of cell-based therapies in a murine model of Parkinson's disease (PD) that is characterized by dopamine (DA) neuron degeneration in the midbrain. We show here that cografting astrocytes, especially those derived from the midbrain, remarkably enhanced NPC-based cell therapeutic outcomes along with robust DA neuron engraftment in PD rats for at least 6 months after transplantation. We further show that engineering of donor astrocytes with Nurr1 and Foxa2, transcription factors that were recently reported to polarize harmful immunogenic glia into the neuroprotective form, further promoted the neurotrophic actions of grafted astrocytes in the cell therapeutic approach. Collectively, these findings suggest that cografting astrocytes could be a potential strategy for successful cell therapeutic outcomes in neurodegenerative disorders.
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Affiliation(s)
- Jae-Jin Song
- Department of Biochemistry and Molecular Biology, College of Medicine.,Hanyang Biomedical Research Institute, and.,Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul, South Korea
| | - Sang-Min Oh
- Department of Biochemistry and Molecular Biology, College of Medicine.,Hanyang Biomedical Research Institute, and.,Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul, South Korea
| | - Oh-Chan Kwon
- Department of Biochemistry and Molecular Biology, College of Medicine.,Hanyang Biomedical Research Institute, and.,Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul, South Korea
| | - Noviana Wulansari
- Department of Biochemistry and Molecular Biology, College of Medicine.,Hanyang Biomedical Research Institute, and.,Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul, South Korea
| | - Hyun-Seob Lee
- Genomic Core Facility, Transdisciplinary Research and Collaboration Division, Translational Research Institute, and.,Biomedical Research Institute, Seoul National University Hospital, Seoul, South Korea
| | - Mi-Yoon Chang
- Department of Biochemistry and Molecular Biology, College of Medicine.,Hanyang Biomedical Research Institute, and
| | - Eunsoo Lee
- Department of Anatomy and Division of Brain Korea 21 PLUS Program for Biomedical Science, Korea University College of Medicine, Seoul, South Korea
| | - Woong Sun
- Department of Anatomy and Division of Brain Korea 21 PLUS Program for Biomedical Science, Korea University College of Medicine, Seoul, South Korea
| | - Sang-Eun Lee
- Department of Physiology and Biomedical Sciences, Seoul National University College of Medicine, Seoul, South Korea
| | - Sunghoe Chang
- Department of Physiology and Biomedical Sciences, Seoul National University College of Medicine, Seoul, South Korea
| | - Heeyoung An
- Center for Neuroscience and.,Center for Glia-Neuron Interaction, Korea Institute of Science and Technology (KIST), Seoul, South Korea.,KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul, South Korea
| | - C Justin Lee
- Center for Neuroscience and.,Center for Glia-Neuron Interaction, Korea Institute of Science and Technology (KIST), Seoul, South Korea
| | - Sang-Hun Lee
- Department of Biochemistry and Molecular Biology, College of Medicine.,Hanyang Biomedical Research Institute, and.,Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul, South Korea
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988
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Wasilewski D, Priego N, Fustero-Torre C, Valiente M. Reactive Astrocytes in Brain Metastasis. Front Oncol 2017; 7:298. [PMID: 29312881 PMCID: PMC5732246 DOI: 10.3389/fonc.2017.00298] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Accepted: 11/20/2017] [Indexed: 11/13/2022] Open
Abstract
Brain metastasis, the secondary growth of malignant cells within the central nervous system (CNS), exceeds the incidence of primary brain tumors (i.e., gliomas) by tenfold and are seemingly on the rise owing to the emergence of novel targeted therapies that are more effective in controlling extracranial disease relatively to intracranial lesions. Despite the fact that metastasis to the brain poses a unmet clinical problem, with afflicted patients carrying significant morbidity and a fatal prognosis, our knowledge as to how metastatic cells manage to adapt to the tissue environment of the CNS remains limited. Answering this question could pave the way for novel and more specific therapeutic modalities in brain metastasis by targeting the specific makeup of the brain metastatic niche. In regard to this, astrocytes have emerged as the major host cell type that cancer cells encounter and interact with during brain metastasis formation. Similarly to other CNS disorders, astrocytes become reactive and respond to the presence of cancer cells by changing their phenotype and significantly influencing the outcome of disseminated cancer cells within the CNS. Here, we summarize the current knowledge on the contribution of reactive astrocytes in brain metastasis by focusing on the signaling pathways and types of interactions that play a crucial part in the communication with cancer cells and how these could be translated into innovative therapies.
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Affiliation(s)
- David Wasilewski
- Brain Metastasis Group, Spanish National Cancer Research Center (CNIO), Madrid, Spain
| | - Neibla Priego
- Brain Metastasis Group, Spanish National Cancer Research Center (CNIO), Madrid, Spain
| | - Coral Fustero-Torre
- Bioinformatics Unit, Spanish National Cancer Research Center (CNIO), Madrid, Spain
| | - Manuel Valiente
- Brain Metastasis Group, Spanish National Cancer Research Center (CNIO), Madrid, Spain
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989
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Satoh JI. Gene expression profiles of M1 and M2 microglia characterized by comparative analysis of public datasets. ACTA ACUST UNITED AC 2017. [DOI: 10.1111/cen3.12426] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Jun-ichi Satoh
- Department of Bioinformatics and Molecular Neuropathology; Meiji Pharmaceutical University; Tokyo Japan
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990
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Lee SH, Suk K. Emerging roles of protein kinases in microglia-mediated neuroinflammation. Biochem Pharmacol 2017; 146:1-9. [DOI: 10.1016/j.bcp.2017.06.137] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 06/30/2017] [Indexed: 11/27/2022]
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991
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Bollinger JL, Collins KE, Patel R, Wellman CL. Behavioral stress alters corticolimbic microglia in a sex- and brain region-specific manner. PLoS One 2017; 12:e0187631. [PMID: 29194444 PMCID: PMC5711022 DOI: 10.1371/journal.pone.0187631] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Accepted: 10/23/2017] [Indexed: 11/18/2022] Open
Abstract
Women are more susceptible to numerous stress-linked psychological disorders (e.g., depression) characterized by dysfunction of corticolimbic brain regions critical for emotion regulation and cognitive function. Although sparsely investigated, a number of studies indicate sex differences in stress effects on neuronal structure, function, and behaviors associated with these regions. We recently demonstrated a basal sex difference in- and differential effects of stress on- microglial activation in medial prefrontal cortex (mPFC). The resident immune cells of the brain, microglia are implicated in synaptic and dendritic plasticity, and cognitive-behavioral function. Here, we examined the effects of acute (3h/day, 1 day) and chronic (3h/day, 10 days) restraint stress on microglial density and morphology, as well as immune factor expression in orbitofrontal cortex (OFC), basolateral amygdala (BLA), and dorsal hippocampus (DHC) in male and female rats. Microglia were visualized, classified based on their morphology, and stereologically counted. Microglia-associated transcripts (CD40, iNOS, Arg1, CX3CL1, CX3CR1, CD200, and CD200R) were assessed in brain punches from each region. Expression of genes linked with cellular stress, neuroimmune state, and neuron-microglia communication varied between unstressed male and female rats in a region-specific manner. In OFC, chronic stress upregulated a wider variety of immune factors in females than in males. Acute stress increased microglia-associated transcripts in BLA in males, whereas chronic stress altered immune factor expression in BLA more broadly in females. In DHC, chronic stress increased immune factor expression in males but not females. Moreover, acute and chronic stress differentially affected microglial morphological activation state in male and female rats across all brain regions investigated. In males, chronic stress altered microglial activation in a pattern consistent with microglial involvement in stress-induced dendritic remodeling across OFC, BLA, and DHC. Together, these data suggest the potential for microglia-mediated sex differences in stress effects on neural structure, function, and behavior.
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Affiliation(s)
- Justin L. Bollinger
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, United States of America
- Program in Neuroscience, Indiana University, Bloomington, IN, United States of America
- Center for the Integrative Study of Animal Behavior, Indiana University, Bloomington, IN, United States of America
| | - Kaitlyn E. Collins
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, United States of America
| | - Rushi Patel
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, United States of America
| | - Cara L. Wellman
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, United States of America
- Program in Neuroscience, Indiana University, Bloomington, IN, United States of America
- Center for the Integrative Study of Animal Behavior, Indiana University, Bloomington, IN, United States of America
- * E-mail:
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992
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Abstract
Microglia and non-parenchymal macrophages in the brain are mononuclear phagocytes that are increasingly recognized to be essential players in the development, homeostasis and diseases of the central nervous system. With the availability of new genetic, molecular and pharmacological tools, considerable advances have been made towards our understanding of the embryonic origins, developmental programmes and functions of these cells. These exciting discoveries, some of which are still controversial, also raise many new questions, which makes brain macrophage biology a fast-growing field at the intersection of neuroscience and immunology. Here, we review the current knowledge of how and where brain macrophages are generated, with a focus on parenchymal microglia. We also discuss their normal functions during development and homeostasis, the disturbance of which may lead to various neurodegenerative and neuropsychiatric diseases.
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993
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Kreisl WC, Henter ID, Innis RB. Imaging Translocator Protein as a Biomarker of Neuroinflammation in Dementia. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2017; 82:163-185. [PMID: 29413519 PMCID: PMC6190574 DOI: 10.1016/bs.apha.2017.08.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Neuroinflammation has long been considered a potential contributor to neurodegenerative disorders that result in dementia. Accumulation of abnormal protein aggregates in Alzheimer's disease, frontotemporal dementia, and dementia with Lewy bodies is associated with the activation of microglia and astrocytes into proinflammatory states, and chronic low-level activation of glial cells likely contributes to the pathological changes observed in these and other neurodegenerative diseases. The 18kDa translocator protein (TSPO) is a key biomarker for measuring inflammation in the brain via positron emission tomography (PET). Increased TSPO density has been observed in brain tissue from patients with neurodegenerative diseases and colocalizes to activated microglia and reactive astrocytes. Several radioligands have been developed to measure TSPO density in vivo with PET, and these have been used in clinical studies of different dementia syndromes. However, TSPO radioligands have limitations, including low specific-to-nonspecific signal and differential affinity to a polymorphism on the TSPO gene, which must be taken into consideration in designing and interpreting human PET studies. Nonetheless, most PET studies have shown that increased TSPO binding is associated with various dementias, suggesting that TSPO has potential as a biomarker to further explore the role of neuroinflammation in dementia pathogenesis and may prove useful in monitoring disease progression.
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Affiliation(s)
- William C Kreisl
- Taub Institute, Columbia University Medical Center, New York, NY, United States.
| | - Ioline D Henter
- Molecular Imaging Branch, National Institute of Mental Health, Bethesda, MD, United States
| | - Robert B Innis
- Molecular Imaging Branch, National Institute of Mental Health, Bethesda, MD, United States
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994
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Tvrdik P, Kalani MYS. In Vivo Imaging of Microglial Calcium Signaling in Brain Inflammation and Injury. Int J Mol Sci 2017; 18:ijms18112366. [PMID: 29117112 PMCID: PMC5713335 DOI: 10.3390/ijms18112366] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Revised: 11/01/2017] [Accepted: 11/04/2017] [Indexed: 12/20/2022] Open
Abstract
Microglia, the innate immune sentinels of the central nervous system, are the most dynamic cells in the brain parenchyma. They are the first responders to insult and mediate neuroinflammation. Following cellular damage, microglia extend their processes towards the lesion, modify their morphology, release cytokines and other mediators, and eventually migrate towards the damaged area and remove cellular debris by phagocytosis. Intracellular Ca2+ signaling plays important roles in many of these functions. However, Ca2+ in microglia has not been systematically studied in vivo. Here we review recent findings using genetically encoded Ca2+ indicators and two-photon imaging, which have enabled new insights into Ca2+ dynamics and signaling pathways in large populations of microglia in vivo. These new approaches will help to evaluate pre-clinical interventions and immunomodulation for pathological brain conditions such as stroke and neurodegenerative diseases.
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Affiliation(s)
- Petr Tvrdik
- Department of Neurosurgery, University of Utah School of Medicine, Salt Lake City, UT 84132, USA.
| | - M Yashar S Kalani
- Department of Neurosurgery, University of Virginia School of Medicine, Charlottesville, VA 22908, USA.
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995
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Labandeira-Garcia JL, Costa-Besada MA, Labandeira CM, Villar-Cheda B, Rodríguez-Perez AI. Insulin-Like Growth Factor-1 and Neuroinflammation. Front Aging Neurosci 2017; 9:365. [PMID: 29163145 PMCID: PMC5675852 DOI: 10.3389/fnagi.2017.00365] [Citation(s) in RCA: 139] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2017] [Accepted: 10/23/2017] [Indexed: 12/15/2022] Open
Abstract
Insulin-like growth factor-1 (IGF-1) effects on aging and neurodegeneration is still controversial. However, it is widely admitted that IGF-1 is involved in the neuroinflammatory response. In peripheral tissues, several studies showed that IGF-1 inhibited the expression of inflammatory markers, although other studies concluded that IGF-1 has proinflammatory functions. Furthermore, proinflammatory cytokines such as TNF-α impaired IGF-1 signaling. In the brain, there are controversial results on effects of IGF-1 in neuroinflammation. In addition to direct protective effects on neurons, several studies revealed anti-inflammatory effects of IGF-1 acting on astrocytes and microglia, and that IGF-1 may also inhibit blood brain barrier permeability. Altogether suggests that the aging-related decrease in IGF-1 levels may contribute to the aging-related pro-inflammatory state. IGF-1 inhibits the astrocytic response to inflammatory stimuli, and modulates microglial phenotype (IGF-1 promotes the microglial M2 and inhibits of M1 phenotype). Furthermore, IGF-1 is mitogenic for microglia. IGF-1 and estrogen interact to modulate the neuroinflammatory response and microglial and astrocytic phenotypes. Brain renin-angiotensin and IGF-1 systems also interact to modulate neuroinflammation. Induction of microglial IGF-1 by angiotensin, and possibly by other pro-inflammatory inducers, plays a major role in the repression of the M1 microglial neurotoxic phenotype and the enhancement of the transition to an M2 microglial repair/regenerative phenotype. This mechanism is impaired in aged brains. Aging-related decrease in IGF-1 may contribute to the loss of capacity of microglia to undergo M2 activation. Fine tuning of IGF-1 levels may be critical for regulating the neuroinflammatory response, and IGF-1 may be involved in inflammation in a context-dependent mode.
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Affiliation(s)
- Jose L Labandeira-Garcia
- Laboratory of Neuroanatomy and Experimental Neurology, Department of Morphological Sciences, CIMUS, University of Santiago de Compostela, Santiago de Compostela, Spain.,Networking Research Center on Neurodegenerative Diseases (CIBERNED), Madrid, Spain
| | - Maria A Costa-Besada
- Laboratory of Neuroanatomy and Experimental Neurology, Department of Morphological Sciences, CIMUS, University of Santiago de Compostela, Santiago de Compostela, Spain.,Networking Research Center on Neurodegenerative Diseases (CIBERNED), Madrid, Spain
| | - Carmen M Labandeira
- Department of Clinical Neurology, Hospital Alvaro Cunqueiro, University Hospital Complex, Vigo, Spain
| | - Begoña Villar-Cheda
- Laboratory of Neuroanatomy and Experimental Neurology, Department of Morphological Sciences, CIMUS, University of Santiago de Compostela, Santiago de Compostela, Spain.,Networking Research Center on Neurodegenerative Diseases (CIBERNED), Madrid, Spain
| | - Ana I Rodríguez-Perez
- Laboratory of Neuroanatomy and Experimental Neurology, Department of Morphological Sciences, CIMUS, University of Santiago de Compostela, Santiago de Compostela, Spain.,Networking Research Center on Neurodegenerative Diseases (CIBERNED), Madrid, Spain
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996
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Espinosa-Garcia C, Sayeed I, Yousuf S, Atif F, Sergeeva EG, Neigh GN, Stein DG. Stress primes microglial polarization after global ischemia: Therapeutic potential of progesterone. Brain Behav Immun 2017. [PMID: 28648389 DOI: 10.1016/j.bbi.2017.06.012] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Despite the fact that stress is associated with increased risk of stroke and worsened outcome, most preclinical studies have ignored this comorbid factor, especially in the context of testing neuroprotective treatments. Preclinical research suggests that stress primes microglia, resulting in an enhanced reactivity to a subsequent insult and potentially increasing vulnerability to stroke. Ischemia-induced activated microglia can be polarized into a harmful phenotype, M1, which produces pro-inflammatory cytokines, or a protective phenotype, M2, which releases anti-inflammatory cytokines and neurotrophic factors. Selective modulation of microglial polarization by inhibiting M1 or stimulating M2 may be a potential therapeutic strategy for treating cerebral ischemia. Our laboratory and others have shown progesterone to be neuroprotective against ischemic stroke in rodents, but it is not known whether it will be as effective under a comorbid condition of chronic stress. Here we evaluated the neuroprotective effect of progesterone on the inflammatory response in the hippocampus after exposure to stress followed by global ischemia. We focused on the effects of microglial M1/M2 polarization and pro- and anti-inflammatory mediators in stressed ischemic animals. Male Sprague-Dawley rats were exposed to 8 consecutive days of social defeat stress and then subjected to global ischemia or sham surgery. The rats received intraperitoneal injections of progesterone (8mg/kg) or vehicle at 2h post-ischemia followed by subcutaneous injections at 6h and once every 24h post-injury for 7days. The animals were killed at 7 and 14days post-ischemia, and brains were removed and processed to assess outcome measures using histological, immunohistochemical and molecular biology techniques. Pre-ischemic stress (1) exacerbated neuronal loss and neurodegeneration as well as microglial activation in the selectively vulnerable CA1 hippocampal region, (2) dysregulated microglial polarization, leading to upregulation of both M1 and M2 phenotype markers, (3) increased pro-inflammatory cytokine expression, and (4) reduced anti-inflammatory cytokine and neurotrophic factor expression in the ischemic hippocampus. Treatment with progesterone significantly attenuated stress-induced microglia priming by modulating polarized microglia and the inflammatory environment in the hippocampus, the area most vulnerable to ischemic injury. Our findings can be taken to suggest that progesterone holds potential as a candidate for clinical testing in ischemic stroke where high stress may be a contributing factor.
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Affiliation(s)
| | - Iqbal Sayeed
- Department of Emergency Medicine, Emory University, Atlanta, GA 30322, USA.
| | - Seema Yousuf
- Department of Emergency Medicine, Emory University, Atlanta, GA 30322, USA.
| | - Fahim Atif
- Department of Emergency Medicine, Emory University, Atlanta, GA 30322, USA.
| | - Elena G Sergeeva
- Department of Emergency Medicine, Emory University, Atlanta, GA 30322, USA.
| | - Gretchen N Neigh
- Department of Psychiatry and Behavioral Sciences, Emory University, Atlanta, GA 30322, USA.
| | - Donald G Stein
- Department of Emergency Medicine, Emory University, Atlanta, GA 30322, USA.
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997
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On phagocytes and macular degeneration. Prog Retin Eye Res 2017; 61:98-128. [DOI: 10.1016/j.preteyeres.2017.06.002] [Citation(s) in RCA: 96] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Revised: 05/29/2017] [Accepted: 06/05/2017] [Indexed: 12/17/2022]
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998
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Zhang J, Xie X, Tang M, Zhang J, Zhang B, Zhao Q, Han Y, Yan W, Peng C, You Z. Salvianolic acid B promotes microglial M2-polarization and rescues neurogenesis in stress-exposed mice. Brain Behav Immun 2017; 66:111-124. [PMID: 28736034 DOI: 10.1016/j.bbi.2017.07.012] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2017] [Revised: 07/08/2017] [Accepted: 07/17/2017] [Indexed: 01/03/2023] Open
Abstract
Although accumulating evidence suggests that activated microglia are associated with deficits in neurogenesis and contribute to the physiopathology of major depressive disorder, the role of microglia in treating depression remains poorly understood. Our previous study showed that salvianolic acid (SalB) has the regulation of neuroinflammatory responses and antidepressant-like effects. Here, we hypothesized that SalB's therapeutic effects occur because it modulates microglial phenotypes that are associated with neurogenesis. To test this hypothesis, we treated CMS-exposed C57BL/6 mice with SalB (20mg/kg, intraperitoneally, once daily) for 3weeks and investigated microglial phenotypic profiles and hippocampal neurogenesis. The results showed that the SalB treatment skewed M1 microglial polarization toward M2 activation in the hippocampus and cortex and remedied CMS-induced deficits in hippocampal neurogenesis. SalB (40µM) inhibited LPS-stimulated microglial M1 activation as well as induced M2 activation in vitro, and the cultured microglia with the SalB treatment showed enhanced neural precursor cell proliferation, differentiation, and survival. SalB treatment also ameliorated the depressive-like behaviors of the CMS-treated mice in sucrose preference, forced swimming, and tail suspension tests. These findings suggest a possible antidepressive mechanism for anti-inflammatory agents that is correlated with microglial polarization and hippocampal neurogenesis and which may provide a new microglia-targeted strategy for depression therapy.
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Affiliation(s)
- Jinqiang Zhang
- School of Life Science and Technology, Center for Informational Biology, University of Electronic Science and Technology of China, Chengdu 610054, China
| | - Xiaofang Xie
- State Key Laboratory Breeding Base of Systematic Research, Development and Utilization of Chinese Medicine Resources, Pharmacy College, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China
| | - Mingming Tang
- School of Life Science and Technology, Center for Informational Biology, University of Electronic Science and Technology of China, Chengdu 610054, China
| | - Jing Zhang
- School of Life Science and Technology, Center for Informational Biology, University of Electronic Science and Technology of China, Chengdu 610054, China
| | - Boyang Zhang
- School of Life Science and Technology, Center for Informational Biology, University of Electronic Science and Technology of China, Chengdu 610054, China
| | - Qiuying Zhao
- School of Life Science and Technology, Center for Informational Biology, University of Electronic Science and Technology of China, Chengdu 610054, China
| | - Yue Han
- School of Life Science and Technology, Center for Informational Biology, University of Electronic Science and Technology of China, Chengdu 610054, China
| | - Wan Yan
- School of Life Science and Technology, Center for Informational Biology, University of Electronic Science and Technology of China, Chengdu 610054, China
| | - Cheng Peng
- State Key Laboratory Breeding Base of Systematic Research, Development and Utilization of Chinese Medicine Resources, Pharmacy College, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China
| | - Zili You
- School of Life Science and Technology, Center for Informational Biology, University of Electronic Science and Technology of China, Chengdu 610054, China.
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999
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Sun M, Brady RD, Wright DK, Kim HA, Zhang SR, Sobey CG, Johnstone MR, O'Brien TJ, Semple BD, McDonald SJ, Shultz SR. Treatment with an interleukin-1 receptor antagonist mitigates neuroinflammation and brain damage after polytrauma. Brain Behav Immun 2017; 66:359-371. [PMID: 28782716 DOI: 10.1016/j.bbi.2017.08.005] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 07/22/2017] [Accepted: 08/02/2017] [Indexed: 01/18/2023] Open
Abstract
Traumatic brain injury (TBI) and long bone fracture are common in polytrauma. This injury combination in mice results in elevated levels of the pro-inflammatory cytokine interleukin-1β (IL-1β) and exacerbated neuropathology when compared to isolated-TBI. Here we examined the effect of treatment with an IL-1 receptor antagonist (IL-1ra) in mice given a TBI and a concomitant tibial fracture (i.e., polytrauma). Adult male C57BL/6 mice were given sham-injuries or polytrauma and treated with saline-vehicle or IL-1ra (100mg/kg). Treatments were subcutaneously injected at 1, 6, and 24h, and then once daily for one week post-injury. 7-8 mice/group were euthanized at 48h post-injury. 12-16 mice/group underwent behavioral testing at 12weeks post-injury and MRI at 14weeks post-injury before being euthanized at 16weeks post-injury. At 48h post-injury, markers for activated microglia and astrocytes, as well as neutrophils and edema, were decreased in polytrauma mice treated with IL-1ra compared to polytrauma mice treated with vehicle. At 14weeks post-injury, MRI analysis demonstrated that IL-1ra treatment after polytrauma reduced volumetric loss in the injured cortex and mitigated track-weighted MRI markers for axonal injury. As IL-1ra (Anakinra) is approved for human use, it may represent a promising therapy in polytrauma cases involving TBI and fracture.
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Affiliation(s)
- Mujun Sun
- Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, VIC 3052, Australia
| | - Rhys D Brady
- Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, VIC 3052, Australia; Department of Physiology, Anatomy and Microbiology, La Trobe University, VIC 3083, Australia
| | - David K Wright
- Department of Anatomy and Neuroscience, The University of Melbourne, Parkville, VIC 3052, Australia; The Florey Institute of Neuroscience and Mental Health, Parkville, VIC 3052, Australia; Departments of Neuroscience and Medicine, Monash University, Melbourne, VIC 3004, Australia
| | - Hyun Ah Kim
- Department of Physiology, Anatomy and Microbiology, La Trobe University, VIC 3083, Australia
| | - Shenpeng R Zhang
- Department of Physiology, Anatomy and Microbiology, La Trobe University, VIC 3083, Australia; Department of Pharmacology, Monash University, Melbourne, VIC 3800, Australia
| | - Christopher G Sobey
- Department of Physiology, Anatomy and Microbiology, La Trobe University, VIC 3083, Australia
| | - Maddison R Johnstone
- Department of Physiology, Anatomy and Microbiology, La Trobe University, VIC 3083, Australia
| | - Terence J O'Brien
- Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, VIC 3052, Australia; Departments of Neuroscience and Medicine, Monash University, Melbourne, VIC 3004, Australia
| | - Bridgette D Semple
- Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, VIC 3052, Australia; Departments of Neuroscience and Medicine, Monash University, Melbourne, VIC 3004, Australia
| | - Stuart J McDonald
- Department of Physiology, Anatomy and Microbiology, La Trobe University, VIC 3083, Australia
| | - Sandy R Shultz
- Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, VIC 3052, Australia; Departments of Neuroscience and Medicine, Monash University, Melbourne, VIC 3004, Australia.
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1000
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Minocycline Has Anti-inflammatory Effects and Reduces Cytotoxicity in an Ex Vivo Spinal Cord Slice Culture Model of West Nile Virus Infection. J Virol 2017; 91:JVI.00569-17. [PMID: 28878079 DOI: 10.1128/jvi.00569-17] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 08/27/2017] [Indexed: 12/13/2022] Open
Abstract
West Nile virus (WNV) is a neurotropic flavivirus that can cause significant neurological disease. Mouse models of WNV infection demonstrate that a proinflammatory environment is induced within the central nervous system (CNS) after WNV infection, leading to entry of activated peripheral immune cells. We utilized ex vivo spinal cord slice cultures (SCSC) to demonstrate that anti-inflammatory mechanisms may also play a role in WNV-induced pathology and/or recovery. Microglia are a type of macrophage that function as resident CNS immune cells. Similar to mouse models, infection of SCSC with WNV induces the upregulation of proinflammatory genes and proteins that are associated with microglial activation, including the microglial activation marker Iba1 and CC motif chemokines CCL2, CCL3, and CCL5. This suggests that microglia assume a proinflammatory phenotype in response to WNV infection similar to the proinflammatory (M1) activation that can be displayed by other macrophages. We now show that the WNV-induced expression of these and other proinflammatory genes was significantly decreased in the presence of minocycline, which has antineuroinflammatory properties, including the ability to inhibit proinflammatory microglial responses. Minocycline also caused a significant increase in the expression of anti-inflammatory genes associated with alternative anti-inflammatory (M2) macrophage activation, including interleukin 4 (IL-4), IL-13, and FIZZ1. Minocycline-dependent alterations to M1/M2 gene expression were associated with a significant increase in survival of neurons, microglia, and astrocytes in WNV-infected slices and markedly decreased levels of inducible nitric oxide synthase (iNOS). These results demonstrate that an anti-inflammatory environment induced by minocycline reduces viral cytotoxicity during WNV infection in ex vivo CNS tissue.IMPORTANCE West Nile virus (WNV) causes substantial morbidity and mortality, with no specific therapeutic treatments available. Antiviral inflammatory responses are a crucial component of WNV pathology, and understanding how they are regulated is important for tailoring effective treatments. Proinflammatory responses during WNV infection have been extensively studied, but anti-inflammatory responses (and their potential protective and reparative capabilities) following WNV infection have not been investigated. Minocycline induced the expression of genes associated with the anti-inflammatory (M2) activation of CNS macrophages (microglia) in WNV-infected SCSC while inhibiting the expression of genes associated with proinflammatory (M1) macrophage activation and was protective for multiple CNS cell types, indicating its potential use as a therapeutic reagent. This ex vivo culture system can uniquely address the ability of CNS parenchymal cells (neurons, astrocytes, and microglia) to respond to minocycline and to modulate the inflammatory environment and cytotoxicity in response to WNV infection without peripheral immune cell involvement.
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