1001
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Minter MR, Hinterleitner R, Meisel M, Zhang C, Leone V, Zhang X, Oyler-Castrillo P, Zhang X, Musch MW, Shen X, Jabri B, Chang EB, Tanzi RE, Sisodia SS. Antibiotic-induced perturbations in microbial diversity during post-natal development alters amyloid pathology in an aged APP SWE/PS1 ΔE9 murine model of Alzheimer's disease. Sci Rep 2017; 7:10411. [PMID: 28874832 PMCID: PMC5585265 DOI: 10.1038/s41598-017-11047-w] [Citation(s) in RCA: 193] [Impact Index Per Article: 27.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Accepted: 08/18/2017] [Indexed: 02/06/2023] Open
Abstract
Recent evidence suggests the commensal microbiome regulates host immunity and influences brain function; findings that have ramifications for neurodegenerative diseases. In the context of Alzheimer’s disease (AD), we previously reported that perturbations in microbial diversity induced by life-long combinatorial antibiotic (ABX) selection pressure in the APPSWE/PS1ΔE9 mouse model of amyloidosis is commensurate with reductions in amyloid-β (Aβ) plaque pathology and plaque-localised gliosis. Considering microbiota-host interactions, specifically during early post-natal development, are critical for immune- and neuro-development we now examine the impact of microbial community perturbations induced by acute ABX exposure exclusively during this period in APPSWE/PS1ΔE9 mice. We show that early post-natal (P) ABX treatment (P14-P21) results in long-term alterations of gut microbial genera (predominantly Lachnospiraceae and S24-7) and reduction in brain Aβ deposition in aged APPSWE/PS1ΔE9 mice. These mice exhibit elevated levels of blood- and brain-resident Foxp3+ T-regulatory cells and display an alteration in the inflammatory milieu of the serum and cerebrospinal fluid. Finally, we confirm that plaque-localised microglia and astrocytes are reduced in ABX-exposed mice. These findings suggest that ABX-induced microbial diversity perturbations during post-natal stages of development coincide with altered host immunity mechanisms and amyloidosis in a murine model of AD.
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Affiliation(s)
- Myles R Minter
- Department of Neurobiology, The University of Chicago, Chicago, IL, 60637, USA.,The Microbiome Center, The University of Chicago, Chicago, IL, 60637, USA
| | - Reinhard Hinterleitner
- Department of Medicine, The University of Chicago, Chicago, IL, 60637, USA.,Committee on Immunology, The University of Chicago, Chicago, IL, 60637, USA
| | - Marlies Meisel
- Department of Medicine, The University of Chicago, Chicago, IL, 60637, USA.,Committee on Immunology, The University of Chicago, Chicago, IL, 60637, USA
| | - Can Zhang
- Department of Neurology, Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Diseases, Massachusetts General Hospital, Charlestown, MA, 02114, USA
| | - Vanessa Leone
- The Microbiome Center, The University of Chicago, Chicago, IL, 60637, USA.,Department of Medicine, The University of Chicago, Chicago, IL, 60637, USA
| | - Xiaoqiong Zhang
- Department of Neurobiology, The University of Chicago, Chicago, IL, 60637, USA
| | | | - Xulun Zhang
- Department of Neurobiology, The University of Chicago, Chicago, IL, 60637, USA
| | - Mark W Musch
- Department of Medicine, The University of Chicago, Chicago, IL, 60637, USA
| | - Xunuo Shen
- Department of Neurology, Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Diseases, Massachusetts General Hospital, Charlestown, MA, 02114, USA
| | - Bana Jabri
- Department of Medicine, The University of Chicago, Chicago, IL, 60637, USA.,Committee on Immunology, The University of Chicago, Chicago, IL, 60637, USA
| | - Eugene B Chang
- The Microbiome Center, The University of Chicago, Chicago, IL, 60637, USA.,Department of Medicine, The University of Chicago, Chicago, IL, 60637, USA
| | - Rudolph E Tanzi
- Department of Neurology, Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Diseases, Massachusetts General Hospital, Charlestown, MA, 02114, USA
| | - Sangram S Sisodia
- Department of Neurobiology, The University of Chicago, Chicago, IL, 60637, USA. .,The Microbiome Center, The University of Chicago, Chicago, IL, 60637, USA.
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1002
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Abstract
There is an increasing recognition that inflammation plays a critical role in neurodegenerative diseases of the CNS, including Alzheimer's disease, amyotrophic lateral sclerosis, Parkinson's disease, and the prototypic neuroinflammatory disease multiple sclerosis (MS). Differential immune responses involving the adaptive versus the innate immune system are observed at various stages of neurodegenerative diseases, and may not only drive disease processes but could serve as therapeutic targets. Ongoing investigations into the specific inflammatory mechanisms that play roles in disease causation and progression have revealed lessons about inflammation-driven neurodegeneration that can be applied to other neurodegenerative diseases. An increasing number of immunotherapeutic strategies that have been successful in MS are now being applied to other neurodegenerative diseases. Some approaches suppress CNS immune mechanisms, while others harness the immune system to clear deleterious products and cells. This Review focuses on the mechanisms by which inflammation, mediated either by the peripheral immune response or by endogenous CNS immune mechanisms, can affect CNS neurodegeneration.
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1003
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Abstract
Microglia are brain-resident myeloid cells that mediate key functions to support the CNS. Microglia express a wide range of receptors that act as molecular sensors, which recognize exogenous or endogenous CNS insults and initiate an immune response. In addition to their classical immune cell function, microglia act as guardians of the brain by promoting phagocytic clearance and providing trophic support to ensure tissue repair and maintain cerebral homeostasis. Conditions associated with loss of homeostasis or tissue changes induce several dynamic microglial processes, including changes of cellular morphology, surface phenotype, secretory mediators, and proliferative responses (referred to as an "activated state"). Activated microglia represent a common pathological feature of several neurodegenerative diseases, including Alzheimer's disease (AD). Cumulative evidence suggests that microglial inflammatory activity in AD is increased while microglial-mediated clearance mechanisms are compromised. Microglia are perpetually engaged in a mutual interaction with the surrounding environment in CNS; thus, diverse microglial reactions at different disease stages may open new avenues for therapeutic intervention and modification of inflammatory activities. In this Review, the role of microglia in the pathogenesis of AD and the modulation of microglia activity as a therapeutic modality will be discussed.
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Affiliation(s)
- Heela Sarlus
- Department of Neurodegenerative Diseases and Gerontopsychiatry, University of Bonn, Bonn, Germany.,Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE), Bonn, Germany
| | - Michael T Heneka
- Department of Neurodegenerative Diseases and Gerontopsychiatry, University of Bonn, Bonn, Germany.,Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE), Bonn, Germany.,Department of Infectious Diseases and Immunology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
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1004
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Zrzavy T, Hametner S, Wimmer I, Butovsky O, Weiner HL, Lassmann H. Loss of 'homeostatic' microglia and patterns of their activation in active multiple sclerosis. Brain 2017; 140:1900-1913. [PMID: 28541408 PMCID: PMC6057548 DOI: 10.1093/brain/awx113] [Citation(s) in RCA: 411] [Impact Index Per Article: 58.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 03/19/2017] [Indexed: 02/07/2023] Open
Abstract
Microglia and macrophages accumulate at the sites of active demyelination and neurodegeneration in the multiple sclerosis brain and are thought to play a central role in the disease process. We used recently described markers to characterize the origin and functional states of microglia/macrophages in acute, relapsing and progressive multiple sclerosis. We found microglia activation in normal white matter of controls and that the degree of activation increased with age. This microglia activation was more pronounced in the normal-appearing white matter of patients in comparison to controls and increased with disease duration. In contrast to controls, the normal-appearing white matter of patients with multiple sclerosis showed a significant reduction of P2RY12, a marker expressed in homeostatic microglia in rodents, which was completely lost in active and slowly expanding lesions. Early stages of demyelination and neurodegeneration in active lesions contained microglia with a pro-inflammatory phenotype, which expressed molecules involved in phagocytosis, oxidative injury, antigen presentation and T cell co-stimulation. In later stages, the microglia and macrophages in active lesions changed to a phenotype that was intermediate between pro- and anti-inflammatory activation. In inactive lesions, the density of microglia/macrophages was significantly reduced and microglia in part converted to a P2RY12+ phenotype. Analysis of TMEM119, which is expressed on microglia but not on recruited macrophages, demonstrated that on average 45% of the macrophage-like cells in active lesions were derived from the resident microglia pool. Our study demonstrates the loss of the homeostatic microglial signature in active multiple sclerosis with restoration associated with disease inactivity.
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Affiliation(s)
- Tobias Zrzavy
- Center for Brain Research, Medical University of Vienna, Austria
| | - Simon Hametner
- Center for Brain Research, Medical University of Vienna, Austria
| | - Isabella Wimmer
- Center for Brain Research, Medical University of Vienna, Austria
| | - Oleg Butovsky
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women´s Hospital, Harvard Medical School, Boston, MA, USA
| | - Howard L Weiner
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women´s Hospital, Harvard Medical School, Boston, MA, USA
| | - Hans Lassmann
- Center for Brain Research, Medical University of Vienna, Austria
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1005
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Kozareva DA, Hueston CM, Ó'Léime CS, Crotty S, Dockery P, Cryan JF, Nolan YM. Absence of the neurogenesis-dependent nuclear receptor TLX induces inflammation in the hippocampus. J Neuroimmunol 2017; 331:87-96. [PMID: 28844503 DOI: 10.1016/j.jneuroim.2017.08.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Revised: 08/18/2017] [Accepted: 08/18/2017] [Indexed: 12/25/2022]
Abstract
The orphan nuclear receptor TLX (Nr2e1) is a key regulator of hippocampal neurogenesis. Impaired adult hippocampal neurogenesis has been reported in neurodegenerative and psychiatric conditions including dementia and stress-related depression. Neuroinflammation is also implicated in the neuropathology of these disorders, and has been shown to negatively affect hippocampal neurogenesis. To investigate a role for TLX in hippocampal neuroinflammation, we assessed microglial activation in the hippocampus of mice with a spontaneous deletion of TLX. Results from our study suggest that a lack of TLX is implicated in deregulation of microglial phenotype and that consequently, the survival and function of newborn cells in the hippocampus is impaired. TLX may be an important target in understanding inflammatory-associated impairments in neurogenesis.
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Affiliation(s)
- Danka A Kozareva
- Department of Anatomy and Neuroscience, University College Cork, Ireland
| | - Cara M Hueston
- Department of Anatomy and Neuroscience, University College Cork, Ireland
| | - Ciarán S Ó'Léime
- Department of Anatomy and Neuroscience, University College Cork, Ireland
| | - Suzanne Crotty
- Department of Anatomy and Neuroscience, University College Cork, Ireland
| | - Peter Dockery
- Department of Anatomy, National University of Ireland, Galway, Ireland
| | - John F Cryan
- Department of Anatomy and Neuroscience, University College Cork, Ireland; APC Microbiome Institute, University College Cork, Ireland
| | - Yvonne M Nolan
- Department of Anatomy and Neuroscience, University College Cork, Ireland; APC Microbiome Institute, University College Cork, Ireland.
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1006
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Beier EE, Neal M, Alam G, Edler M, Wu LJ, Richardson JR. Alternative microglial activation is associated with cessation of progressive dopamine neuron loss in mice systemically administered lipopolysaccharide. Neurobiol Dis 2017; 108:115-127. [PMID: 28823928 DOI: 10.1016/j.nbd.2017.08.009] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Revised: 07/17/2017] [Accepted: 08/16/2017] [Indexed: 12/12/2022] Open
Abstract
Inflammation arising from central and/or peripheral sources contributes to the pathogenesis of multiple neurodegenerative diseases including Parkinson's disease (PD). Emerging data suggest that differential activation of glia could lead to the pathogenesis and progression of PD. Here, we sought to determine the relationship between lipopolysaccharide (LPS) treatment, loss of dopaminergic neurons and differential activation of glia. Using a model of repeated injections with LPS (1mg/kg, i.p. for 4days), we found that LPS induced a 34% loss of dopamine neurons in the substantia nigra 19days after initiation of treatment, but no further cell loss was observed at 36days. LPS induced a strong pro-inflammatory response with increased mRNA expression of pro-inflammatory markers, including tumor necrosis factor-α (4.8-fold), inducible nitric oxide synthase (2.0-fold), interleukin-1 beta (8.9-fold), interleukin-6 (10.7-fold), and robust glial activation were observed at 1day after final dose of LPS. These pro-inflammatory genes were then reduced at 19days after treatment, when there was a rise in the anti-inflammatory genes Ym1 (1.8-fold) and arginase-1 (2.6-fold). Additionally, 36days after the last LPS injection there was a significant increase in interleukin-10 (2.1-fold) expression. The qPCR data results were supported by protein data, including cytokine measurements, western blotting, and immunofluorescence in brain microglia. Taken together, these data demonstrate that progressive neurodegeneration in the substantia nigra following LPS is likely arrested by microglia shifting to an anti-inflammatory phenotype. Thus, strategies to promote resolution of neuroinflammation may be a promising avenue to slow the progressive loss of dopamine neurons in PD.
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Affiliation(s)
- Eric E Beier
- Environmental and Occupational Health Sciences Institute, Rutgers University, Piscataway, NJ, United States
| | - Matthew Neal
- Department of Pharmaceutical Sciences, Center for Neurodegenerative Disease and Aging, Northeast Ohio Medical University, Rootstown, OH, United States
| | - Gelerah Alam
- Department of Pharmaceutical Sciences, Center for Neurodegenerative Disease and Aging, Northeast Ohio Medical University, Rootstown, OH, United States
| | - Melissa Edler
- Department of Pharmaceutical Sciences, Center for Neurodegenerative Disease and Aging, Northeast Ohio Medical University, Rootstown, OH, United States
| | - Long-Jun Wu
- Department of Neurology, Mayo Clinic, Rochester, MN, United States
| | - Jason R Richardson
- Environmental and Occupational Health Sciences Institute, Rutgers University, Piscataway, NJ, United States; Department of Pharmaceutical Sciences, Center for Neurodegenerative Disease and Aging, Northeast Ohio Medical University, Rootstown, OH, United States.
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1007
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Kuboyama T, Wahane S, Huang Y, Zhou X, Wong JK, Koemeter-Cox A, Martini M, Friedel RH, Zou H. HDAC3 inhibition ameliorates spinal cord injury by immunomodulation. Sci Rep 2017; 7:8641. [PMID: 28819194 PMCID: PMC5561061 DOI: 10.1038/s41598-017-08535-4] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 07/13/2017] [Indexed: 11/30/2022] Open
Abstract
Following spinal cord injury (SCI), the innate immune response of microglia and infiltrating macrophages clears up cellular debris and promotes tissue repair, but it also inflicts secondary injury from inflammatory responses. Immunomodulation aimed at maximizing the beneficial effects while minimizing the detrimental roles of the innate immunity may aid functional recovery after SCI. However, intracellular drivers of global reprogramming of the inflammatory gene networks in the innate immune cells are poorly understood. Here we show that SCI resulted in an upregulation of histone deacetylase 3 (HDAC3) in the innate immune cells at the injury site. Remarkably, blocking HDAC3 with a selective small molecule inhibitor shifted microglia/macrophage responses towards inflammatory suppression, resulting in neuroprotective phenotypes and improved functional recovery in SCI model. Mechanistically, HDAC3 activity is largely responsible for histone deacetylation and inflammatory responses of primary microglia to classic inflammatory stimuli. Our results reveal a novel function of HDAC3 inhibitor in promoting functional recovery after SCI by dampening inflammatory cytokines, thus pointing towards a new direction of immunomodulation for SCI repair.
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Affiliation(s)
- Tomoharu Kuboyama
- Fishberg Department of Neuroscience, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, 10029, USA.,Division of Neuromedical Science, Institute of Natural Medicine, University of Toyama, Toyama, 930-0194, Japan
| | - Shalaka Wahane
- Fishberg Department of Neuroscience, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, 10029, USA
| | - Yong Huang
- Fishberg Department of Neuroscience, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, 10029, USA
| | - Xiang Zhou
- Fishberg Department of Neuroscience, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, 10029, USA
| | - Jamie K Wong
- Fishberg Department of Neuroscience, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, 10029, USA.,Tisch MS Research Center of New York, New York, New York, 10019, USA
| | - Andrew Koemeter-Cox
- Fishberg Department of Neuroscience, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, 10029, USA.,Alzheimer's Drug Discovery Foundation New York, New York, 10019, USA
| | - Michael Martini
- Fishberg Department of Neuroscience, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, 10029, USA
| | - Roland H Friedel
- Fishberg Department of Neuroscience, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, 10029, USA.,Department of Neurosurgery, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, 10029, USA
| | - Hongyan Zou
- Fishberg Department of Neuroscience, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, 10029, USA. .,Department of Neurosurgery, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, 10029, USA.
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1008
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Cheon SY, Kim EJ, Kim JM, Kam EH, Ko BW, Koo BN. Regulation of Microglia and Macrophage Polarization via Apoptosis Signal-Regulating Kinase 1 Silencing after Ischemic/Hypoxic Injury. Front Mol Neurosci 2017; 10:261. [PMID: 28855861 PMCID: PMC5557792 DOI: 10.3389/fnmol.2017.00261] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 07/31/2017] [Indexed: 12/28/2022] Open
Abstract
Inflammation is implicated in ischemic stroke and is involved in abnormal homeostasis. Activation of the immune system leads to breakdown of the blood-brain barrier and, thereby, infiltration of immune cells into the brain. Upon cerebral ischemia, infiltrated macrophages and microglia (resident CNS immune cell) are activated, change their phenotype to M1 or M2 based on the microenvironment, migrate toward damaged tissue, and are involved in repair or damage. Those of M1 phenotype release pro-inflammatory mediators, which are associated with tissue damage, while those of M2 phenotype release anti-inflammatory mediators, which are related to tissue recovery. Moreover, late inflammation continually stimulates immune cell infiltration and leads to brain infarction. Therefore, regulation of M1/M2 phenotypes under persistent inflammatory conditions after cerebral ischemia is important for brain repair. Herein, we focus on apoptosis signal-regulating kinase 1 (ASK1), which is involved in apoptotic cell death, brain infarction, and production of inflammatory mediators after cerebral ischemia. We hypothesized that ASK1 is involved in the polarization of M1/M2 phenotype and the function of microglia and macrophage during the late stage of ischemia/hypoxia. We investigated the effects of ASK1 in mice subjected to middle cerebral artery occlusion and on BV2 microglia and RAW264.7 macrophage cell lines subjected to oxygen-glucose deprivation. Our results showed that ASK1 silencing effectively reduced Iba-1 or CD11b-positive cells in ischemic areas, suppressed pro-inflammatory cytokines, and increased anti-inflammatory mediator levels at 7 days after cerebral ischemia. In cultured microglia and macrophages, ASK1 inhibition, induced by NQDI-1 drug, decreased the expression and release of M1-associated factors and increased those of M2-associated factors after hypoxia/reperfusion (H/R). At the gene level, ASK1 inhibition suppressed M1-associated genes and augmented M2-associated genes. In gap closure assay, ASK1 inhibition reduced the migration rate of microglia and macrophages after H/R. Taken together, our results provide new information that suggests ASK1 controls the polarization of M1/M2 and the function of microglia and macrophage under sustained-inflammatory conditions. Regulation of persistent inflammation via M1/M2 polarization by ASK1 is a novel strategy for repair after ischemic stroke.
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Affiliation(s)
- So Yeong Cheon
- Department of Anesthesiology and Pain Medicine, Yonsei University College of MedicineSeoul, South Korea.,Anesthesia and Pain Research Institute, Yonsei University College of MedicineSeoul, South Korea
| | - Eun Jung Kim
- Department of Anesthesiology and Pain Medicine, Yonsei University College of MedicineSeoul, South Korea.,Anesthesia and Pain Research Institute, Yonsei University College of MedicineSeoul, South Korea
| | - Jeong Min Kim
- Department of Anesthesiology and Pain Medicine, Yonsei University College of MedicineSeoul, South Korea.,Anesthesia and Pain Research Institute, Yonsei University College of MedicineSeoul, South Korea
| | - Eun Hee Kam
- Department of Anesthesiology and Pain Medicine, Yonsei University College of MedicineSeoul, South Korea.,Anesthesia and Pain Research Institute, Yonsei University College of MedicineSeoul, South Korea
| | - Byung Woong Ko
- Department of Anesthesiology and Pain Medicine, Yonsei University College of MedicineSeoul, South Korea
| | - Bon-Nyeo Koo
- Department of Anesthesiology and Pain Medicine, Yonsei University College of MedicineSeoul, South Korea.,Anesthesia and Pain Research Institute, Yonsei University College of MedicineSeoul, South Korea
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1009
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Walker DG, Tang TM, Lue LF. Studies on Colony Stimulating Factor Receptor-1 and Ligands Colony Stimulating Factor-1 and Interleukin-34 in Alzheimer's Disease Brains and Human Microglia. Front Aging Neurosci 2017; 9:244. [PMID: 28848420 PMCID: PMC5552759 DOI: 10.3389/fnagi.2017.00244] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2017] [Accepted: 07/12/2017] [Indexed: 01/08/2023] Open
Abstract
Microglia are dependent on signaling through the colony stimulating factor-1 receptor (CSF-1R/CD115) for growth and survival. Activation of CSF-1R can lead to cell division, while blocking CSF-1R can lead to rapid microglia cell death. CSF-1R has two ligands, the growth factors colony stimulating factor-1 (CSF-1) and the more recently identified interleukin-34 (IL-34). Studies of IL-34 activation of rodent microglia and human macrophages have suggested it has different properties to CSF-1, resulting in an anti-inflammatory reparative phenotype. The goal of this study was to identify if the responses of human postmortem brain microglia to IL-34 differed from their responses to CSF-1 with the aim of identifying different phenotypes of microglia as a result of their responses. To approach this question, we also sought to identify differences between IL-34, CSF-1, and CSF-1R expression in human brain samples to establish whether there was an imbalance in Alzheimer's disease (AD). Using human brain samples [inferior temporal gyrus (ITG) and middle temporal gyrus (MTG)] from distinct cohorts of AD, control and high pathology, or mild cognitive impairment cases, we showed that there was increased expression of CSF-1R and CSF-1 mRNAs in both series of AD cases, and reduced expression of IL-34 mRNA in AD ITG samples. There was no change in expression of these genes in RNA from cerebellum of AD, Parkinson's disease (PD), or control cases. The results suggested an imbalance in CSF-1R signaling in AD. Using RNA sequencing to compare gene expression responses of CSF-1 and IL-34 stimulated human microglia, a profile of responses to CSF-1 and IL-34 was identified. Contrary to earlier work with rodent microglia, IL-34 induced primarily a classical activation response similar to that of CSF-1. It was not possible to identify any genes expressed significantly different by IL-34-stimulated microglia compared to CSF-1-stimulated microglia, but both cytokines did induce certain alternative activation-associated genes. These profiles also showed that a number of genes associated with lysosomal function and Aβ removal were downregulated by IL-34 and CSF-1 stimulation. Compared to earlier results our data indicate that CSF-1R stimulation by IL-34 or CSF-1 produced similar types of responses by elderly postmortem brain-derived microglia.
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Affiliation(s)
- Douglas G Walker
- Neurodegenerative Disease Research Center, Biodesign Institute, Arizona State UniversityTempe, AZ, United States.,Laboratory of Neuroinflammation, Banner Sun Health Research Institute, Sun CityArizona, AZ, United States
| | - Tiffany M Tang
- Neurodegenerative Disease Research Center, Biodesign Institute, Arizona State UniversityTempe, AZ, United States
| | - Lih-Fen Lue
- Neurodegenerative Disease Research Center, Biodesign Institute, Arizona State UniversityTempe, AZ, United States.,Laboratory of Neuroinflammation, Banner Sun Health Research Institute, Sun CityArizona, AZ, United States
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1010
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Holtman IR, Skola D, Glass CK. Transcriptional control of microglia phenotypes in health and disease. J Clin Invest 2017; 127:3220-3229. [PMID: 28758903 DOI: 10.1172/jci90604] [Citation(s) in RCA: 130] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Microglia are the main resident macrophage population of the CNS and perform numerous functions required for CNS development, homeostasis, immunity, and repair. Many lines of evidence also indicate that dysregulation of microglia contributes to the pathogenesis of neurodegenerative and behavioral diseases. These observations provide a compelling argument to more clearly define the mechanisms that control microglia identity and function in health and disease. In this Review, we present a conceptual framework for how different classes of transcription factors interact to select and activate regulatory elements that control microglia development and their responses to internal and external signals. We then describe functions of specific transcription factors in normal and pathological contexts and conclude with a consideration of open questions to be addressed in the future.
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Affiliation(s)
- Inge R Holtman
- Department of Cellular and Molecular Medicine, UCSD, San Diego, California, USA.,Department of Medical Physiology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Dylan Skola
- Department of Cellular and Molecular Medicine, UCSD, San Diego, California, USA
| | - Christopher K Glass
- Department of Cellular and Molecular Medicine, UCSD, San Diego, California, USA.,Department of Medicine, UCSD, San Diego, California, USA
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1011
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Modulation of Astrocyte Activity by Cannabidiol, a Nonpsychoactive Cannabinoid. Int J Mol Sci 2017; 18:ijms18081669. [PMID: 28788104 PMCID: PMC5578059 DOI: 10.3390/ijms18081669] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 07/26/2017] [Accepted: 07/26/2017] [Indexed: 02/07/2023] Open
Abstract
The astrocytes have gained in recent decades an enormous interest as a potential target for neurotherapies, due to their essential and pleiotropic roles in brain physiology and pathology. Their precise regulation is still far from understood, although several candidate molecules/systems arise as promising targets for astrocyte-mediated neuroregulation and/or neuroprotection. The cannabinoid system and its ligands have been shown to interact and affect activities of astrocytes. Cannabidiol (CBD) is the main non-psychotomimetic cannabinoid derived from Cannabis. CBD is devoid of direct CB1 and CB2 receptor activity, but exerts a number of important effects in the brain. Here, we attempt to sum up the current findings on the effects of CBD on astrocyte activity, and in this way on central nervous system (CNS) functions, across various tested models and neuropathologies. The collected data shows that increased astrocyte activity is suppressed in the presence of CBD in models of ischemia, Alzheimer-like and Multiple-Sclerosis-like neurodegenerations, sciatic nerve injury, epilepsy, and schizophrenia. Moreover, CBD has been shown to decrease proinflammatory functions and signaling in astrocytes.
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1012
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Cerri C, Caleo M, Bozzi Y. Chemokines as new inflammatory players in the pathogenesis of epilepsy. Epilepsy Res 2017; 136:77-83. [PMID: 28780154 DOI: 10.1016/j.eplepsyres.2017.07.016] [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: 05/08/2017] [Revised: 07/13/2017] [Accepted: 07/25/2017] [Indexed: 12/22/2022]
Abstract
A large series of clinical and experimental studies supports a link between inflammation and epilepsy, indicating that inflammatory processes within the brain are important contributors to seizure recurrence and precipitation. Systemic inflammation can precipitate seizures in children suffering from epileptic encephalopathies, and hallmarks of a chronic inflammatory state have been found in patients with temporal lobe epilepsy. Research performed on animal models of epilepsy further corroborates the idea that seizures upregulate inflammatory mediators, which in turn may enhance brain excitability and neuronal degeneration. Several inflammatory molecules and their signaling pathways have been implicated in epilepsy. Among these, the chemokine pathway has increasingly gained attention. Chemokines are small cytokines secreted by blood cells, which act as chemoattractants for leukocyte migration. Recent studies indicate that chemokines and their receptors are also produced by brain cells, and are involved in various neurological disorders including epilepsy. In this review, we will focus on a subset of pro-inflammatory chemokines (namely CCL2, CCL3, CCL5, CX3CL1) and their receptors, and their increasingly recognized role in seizure control.
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Affiliation(s)
- Chiara Cerri
- CNR Neuroscience Institute, via G. Moruzzi 1, 56124, Pisa, Italy; Fondazione Umberto Veronesi, Piazza Velasca 5, 20122 Milano, Italy.
| | - Matteo Caleo
- CNR Neuroscience Institute, via G. Moruzzi 1, 56124, Pisa, Italy.
| | - Yuri Bozzi
- CNR Neuroscience Institute, via G. Moruzzi 1, 56124, Pisa, Italy; Neurodevelopmental Disorders Research Group, Centre for Mind/Brain Sciences, University of Trento, via Sommarive 9, 38123 Povo, Trento, Italy.
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1013
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Geloso MC, Corvino V, Marchese E, Serrano A, Michetti F, D'Ambrosi N. The Dual Role of Microglia in ALS: Mechanisms and Therapeutic Approaches. Front Aging Neurosci 2017; 9:242. [PMID: 28790913 PMCID: PMC5524666 DOI: 10.3389/fnagi.2017.00242] [Citation(s) in RCA: 157] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 07/11/2017] [Indexed: 12/14/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by a non-cell autonomous motor neuron loss. While it is generally believed that the disease onset takes place inside motor neurons, different cell types mediating neuroinflammatory processes are considered deeply involved in the progression of the disease. On these grounds, many treatments have been tested on ALS animals with the aim of inhibiting or reducing the pro-inflammatory action of microglia and astrocytes and counteract the progression of the disease. Unfortunately, these anti-inflammatory therapies have been only modestly successful. The non-univocal role played by microglia during stress and injuries might explain this failure. Indeed, it is now well recognized that, during ALS, microglia displays different phenotypes, from surveillant in early stages, to activated states, M1 and M2, characterized by the expression of respectively harmful and protective genes in later phases of the disease. Consistently, the inhibition of microglial function seems to be a valid strategy only if the different stages of microglia polarization are taken into account, interfering with the reactivity of microglia specifically targeting only the harmful pathways and/or potentiating the trophic ones. In this review article, we will analyze the features and timing of microglia activation in the light of M1/M2 phenotypes in the main mice models of ALS. Moreover, we will also revise the results obtained by different anti-inflammatory therapies aimed to unbalance the M1/M2 ratio, shifting it towards a protective outcome.
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Affiliation(s)
- Maria Concetta Geloso
- Institute of Anatomy and Cell Biology, Università Cattolica del Sacro CuoreRome, Italy
| | - Valentina Corvino
- Institute of Anatomy and Cell Biology, Università Cattolica del Sacro CuoreRome, Italy
| | - Elisa Marchese
- Institute of Anatomy and Cell Biology, Università Cattolica del Sacro CuoreRome, Italy
| | - Alessia Serrano
- Institute of Anatomy and Cell Biology, Università Cattolica del Sacro CuoreRome, Italy
| | - Fabrizio Michetti
- Institute of Anatomy and Cell Biology, Università Cattolica del Sacro CuoreRome, Italy.,IRCCS San Raffaele Scientific Institute, Università Vita-Salute San RaffaeleMilan, Italy
| | - Nadia D'Ambrosi
- Department of Biology, University of Rome Tor VergataRome, Italy
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1014
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Bohlen CJ, Bennett FC, Tucker AF, Collins HY, Mulinyawe SB, Barres BA. Diverse Requirements for Microglial Survival, Specification, and Function Revealed by Defined-Medium Cultures. Neuron 2017; 94:759-773.e8. [PMID: 28521131 DOI: 10.1016/j.neuron.2017.04.043] [Citation(s) in RCA: 402] [Impact Index Per Article: 57.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2016] [Revised: 03/31/2017] [Accepted: 04/28/2017] [Indexed: 12/14/2022]
Abstract
Microglia, the resident macrophages of the CNS, engage in various CNS-specific functions that are critical for development and health. To better study microglia and the properties that distinguish them from other tissue macrophage populations, we have optimized serum-free culture conditions to permit robust survival of highly ramified adult microglia under defined-medium conditions. We find that astrocyte-derived factors prevent microglial death ex vivo and that this activity results from three primary components, CSF-1/IL-34, TGF-β2, and cholesterol. Using microglial cultures that have never been exposed to serum, we demonstrate a dramatic and lasting change in phagocytic capacity after serum exposure. Finally, we find that mature microglia rapidly lose signature gene expression after isolation, and that this loss can be reversed by engrafting cells back into an intact CNS environment. These data indicate that the specialized gene expression profile of mature microglia requires continuous instructive signaling from the intact CNS.
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Affiliation(s)
- Christopher J Bohlen
- Department of Neurobiology, Stanford University School of Medicine, Stanford, CA 94305, USA.
| | - F Chris Bennett
- Department of Neurobiology, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Andrew F Tucker
- Department of Neurobiology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Hannah Y Collins
- Department of Neurobiology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Sara B Mulinyawe
- Department of Neurobiology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Ben A Barres
- Department of Neurobiology, Stanford University School of Medicine, Stanford, CA 94305, USA
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1015
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Belle L, Zhou V, Stuhr KL, Beatka M, Siebers EM, Knight JM, Lawlor MW, Weaver C, Hashizume M, Hillard CJ, Drobyski WR. Host interleukin 6 production regulates inflammation but not tryptophan metabolism in the brain during murine GVHD. JCI Insight 2017; 2:93726. [PMID: 28724796 DOI: 10.1172/jci.insight.93726] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 06/06/2017] [Indexed: 12/16/2022] Open
Abstract
Graft-versus-host disease (GVHD) induces pathological damage in peripheral target organs leading to well-characterized, organ-specific clinical manifestations. Patients with GVHD, however, can also have behavioral alterations that affect overall cognitive function, but the extent to which GVHD alters inflammatory and biochemical pathways in the brain remain poorly understood. In the current study, we employed complementary murine GVHD models to demonstrate that alloreactive donor T cells accumulate in the brain and affect a proinflammatory cytokine milieu that is associated with specific behavioral abnormalities. Host IL-6 was identified as a pivotal cytokine mediator, as was host indoleamine 2,3-dioxygenase (IDO-1), which was upregulated in GVHD in an IL-6-dependent manner in microglial cells and was accompanied by dysregulated tryptophan metabolism in the dorsal raphe nucleus and prefrontal cortex. Blockade of the IL-6 signaling pathway significantly reduced donor T cell accumulation, inflammatory cytokine gene expression, and host microglial cell expansion, but did not reverse GVHD-induced tryptophan metabolite dysregulation. Thus, these results indicate that inhibition of IL-6 signaling attenuates neuroinflammation, but does not reverse all of the metabolic abnormalities in the brain during GVHD, which may also have implications for the treatment of neurotoxicity occurring after other T cell-based immune therapies with IL-6-directed approaches.
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Affiliation(s)
| | | | | | | | | | | | - Michael W Lawlor
- Department of Pathology and Laboratory Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Casey Weaver
- University of Alabama Birmingham, Birmingham, Alabama, USA
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1016
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Thelin EP, Tajsic T, Zeiler FA, Menon DK, Hutchinson PJA, Carpenter KLH, Morganti-Kossmann MC, Helmy A. Monitoring the Neuroinflammatory Response Following Acute Brain Injury. Front Neurol 2017; 8:351. [PMID: 28775710 PMCID: PMC5517395 DOI: 10.3389/fneur.2017.00351] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 07/04/2017] [Indexed: 12/11/2022] Open
Abstract
Traumatic brain injury (TBI) and subarachnoid hemorrhage (SAH) are major contributors to morbidity and mortality. Following the initial insult, patients may deteriorate due to secondary brain damage. The underlying molecular and cellular cascades incorporate components of the innate immune system. There are different approaches to assess and monitor cerebral inflammation in the neuro intensive care unit. The aim of this narrative review is to describe techniques to monitor inflammatory activity in patients with TBI and SAH in the acute setting. The analysis of pro- and anti-inflammatory cytokines in compartments of the central nervous system (CNS), including the cerebrospinal fluid and the extracellular fluid, represent the most common approaches to monitor surrogate markers of cerebral inflammatory activity. Each of these compartments has a distinct biology that reflects local processes and the cross-talk between systemic and CNS inflammation. Cytokines have been correlated to outcomes as well as ongoing, secondary injury progression. Alongside the dynamic, focal assay of humoral mediators, imaging, through positron emission tomography, can provide a global in vivo measurement of inflammatory cell activity, which reveals long-lasting processes following the initial injury. Compared to the innate immune system activated acutely after brain injury, the adaptive immune system is likely to play a greater role in the chronic phase as evidenced by T-cell-mediated autoreactivity toward brain-specific proteins. The most difficult aspect of assessing neuroinflammation is to determine whether the processes monitored are harmful or beneficial to the brain as accumulating data indicate a dual role for these inflammatory cascades following injury. In summary, the inflammatory component of the complex injury cascade following brain injury may be monitored using different modalities. Using a multimodal monitoring approach can potentially aid in the development of therapeutics targeting different aspects of the inflammatory cascade and improve the outcome following TBI and SAH.
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Affiliation(s)
- Eric Peter Thelin
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom.,Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Tamara Tajsic
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
| | - Frederick Adam Zeiler
- Division of Anaesthesia, Department of Medicine, University of Cambridge, Cambridge, United Kingdom.,Rady Faculty of Health Sciences, Department of Surgery, University of Manitoba, Winnipeg, MB, Canada.,Clinician Investigator Program, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - David K Menon
- Division of Anaesthesia, Department of Medicine, University of Cambridge, Cambridge, United Kingdom.,Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
| | - Peter J A Hutchinson
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom.,Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
| | - Keri L H Carpenter
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom.,Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
| | - Maria Cristina Morganti-Kossmann
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, VIC, Australia.,Department of Child Health, Barrow Neurological Institute at Phoenix Children's Hospital, University of Arizona College of Medicine, Phoenix, Phoenix, AZ, United States
| | - Adel Helmy
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
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1017
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Katoh M, Wu B, Nguyen HB, Thai TQ, Yamasaki R, Lu H, Rietsch AM, Zorlu MM, Shinozaki Y, Saitoh Y, Saitoh S, Sakoh T, Ikenaka K, Koizumi S, Ransohoff RM, Ohno N. Polymorphic regulation of mitochondrial fission and fusion modifies phenotypes of microglia in neuroinflammation. Sci Rep 2017; 7:4942. [PMID: 28694451 PMCID: PMC5503944 DOI: 10.1038/s41598-017-05232-0] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Accepted: 05/25/2017] [Indexed: 12/18/2022] Open
Abstract
Microglia are the resident macrophages of the central nervous system and play complex roles in the milieu of diseases including the primary diseases of myelin. Although mitochondria are critical for cellular functions and survival in the nervous system, alterations in and the roles of mitochondrial dynamics and associated signaling in microglia are still poorly understood. In the present study, by combining immunohistochemistry and 3D ultrastructural analyses, we show that mitochondrial fission/fusion in reactive microglia is differentially regulated from that in monocyte-derived macrophages and the ramified microglia of normal white matter in myelin disease models. Mouse cerebral microglia in vitro demonstrated that stimulation of TLR4 with lipopolysaccharide, widely used to examine microglial reactions, caused the activation of the mitochondrial fission protein, dynamin-related protein 1 (Drp1) and enhanced production of reactive oxygen species (ROS). The increase in the ROS level activated 5' adenosine monophosphate-activated protein kinase (AMPK), and facilitated elongation of mitochondria along the microtubule tracks. These results suggest that the polymorphic regulation of mitochondrial fission and fusion in reactive microglia is mediated by distinct signaling under inflammatory conditions, and modulates microglial phenotypes through the production of ROS.
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Affiliation(s)
- Mitsuhiko Katoh
- Departments of Anatomy and Molecular Histology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Chuo, Yamanashi, 409-3898, Japan
| | - Bao Wu
- Departments of Anatomy and Molecular Histology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Chuo, Yamanashi, 409-3898, Japan.,Department of Histology and Embryology, Medical College of Chifeng University, Inner Mongolia, 024000, China
| | - Huy Bang Nguyen
- Departments of Anatomy and Molecular Histology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Chuo, Yamanashi, 409-3898, Japan
| | - Truc Quynh Thai
- Departments of Anatomy and Molecular Histology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Chuo, Yamanashi, 409-3898, Japan
| | - Ryo Yamasaki
- Neuroinflammation Research Center, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, 44195, USA
| | - Haiyan Lu
- Neuroinflammation Research Center, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, 44195, USA
| | - Anna M Rietsch
- Neuroinflammation Research Center, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, 44195, USA
| | - Musab M Zorlu
- Neuroinflammation Research Center, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, 44195, USA
| | - Youichi Shinozaki
- Neuropharmacology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Chuo, Yamanashi, 409-3898, Japan
| | - Yurika Saitoh
- Departments of Anatomy and Molecular Histology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Chuo, Yamanashi, 409-3898, Japan
| | - Sei Saitoh
- Departments of Anatomy and Molecular Histology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Chuo, Yamanashi, 409-3898, Japan
| | - Takashi Sakoh
- Departments of Anatomy and Molecular Histology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Chuo, Yamanashi, 409-3898, Japan
| | - Kazuhiro Ikenaka
- Division of Neurobiology and Bioinformatics, National Institute for Physiological Sciences, Okazaki, Aichi, 444-8787, Japan
| | - Schuichi Koizumi
- Neuropharmacology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Chuo, Yamanashi, 409-3898, Japan
| | - Richard M Ransohoff
- Neuroinflammation Research Center, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, 44195, USA
| | - Nobuhiko Ohno
- Departments of Anatomy and Molecular Histology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Chuo, Yamanashi, 409-3898, Japan. .,Division of Neurobiology and Bioinformatics, National Institute for Physiological Sciences, Okazaki, Aichi, 444-8787, Japan.
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1018
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Type-I interferon pathway in neuroinflammation and neurodegeneration: focus on Alzheimer's disease. J Neural Transm (Vienna) 2017; 125:797-807. [PMID: 28676934 DOI: 10.1007/s00702-017-1745-4] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 06/09/2017] [Indexed: 12/18/2022]
Abstract
Past research in Alzheimer's disease (AD) has largely been driven by the amyloid hypothesis; the accompanying neuroinflammation seen in AD has been assumed to be consequential and not disease modifying or causative. However, recent data from both clinical and preclinical studies have established that the immune-driven neuroinflammation contributes to AD pathology. Key evidence for the involvement of neuroinflammation in AD includes enhanced microglial and astroglial activation in the brains of AD patients, increased pro-inflammatory cytokine burden in AD brains, and epidemiological evidence that chronic non-steroidal anti-inflammatory drug use prior to disease onset leads to a lower incidence of AD. Identifying critical mediators controlling this neuroinflammation will prove beneficial in developing anti-inflammatory therapies for the treatment of AD. The type-I interferons (IFNs) are pleiotropic cytokines that control pro-inflammatory cytokine secretion and are master regulators of the innate immune response that impact on disorders of the central nervous system. This review provides evidence that the type-I IFNs play a critical role in the exacerbation of neuroinflammation and actively contribute to the progression of AD.
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1019
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Lan X, Han X, Li Q, Yang QW, Wang J. Modulators of microglial activation and polarization after intracerebral haemorrhage. Nat Rev Neurol 2017; 13:420-433. [PMID: 28524175 PMCID: PMC5575938 DOI: 10.1038/nrneurol.2017.69] [Citation(s) in RCA: 522] [Impact Index Per Article: 74.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Intracerebral haemorrhage (ICH) is the most lethal subtype of stroke but currently lacks effective treatment. Microglia are among the first non-neuronal cells on the scene during the innate immune response to ICH. Microglia respond to acute brain injury by becoming activated and developing classic M1-like (proinflammatory) or alternative M2-like (anti-inflammatory) phenotypes. This polarization implies as yet unrecognized actions of microglia in ICH pathology and recovery, perhaps involving microglial production of proinflammatory or anti-inflammatory cytokines and chemokines. Furthermore, alternatively activated M2-like microglia might promote phagocytosis of red blood cells and tissue debris, a major contribution to haematoma clearance. Interactions between microglia and other cells modulate microglial activation and function, and are also important in ICH pathology. This Review summarizes key studies on modulators of microglial activation and polarization after ICH, including M1-like and M2-like microglial phenotype markers, transcription factors and key signalling pathways. Microglial phagocytosis, haematoma resolution, and the potential crosstalk between microglia and T lymphocytes, neurons, astrocytes, and oligodendrocytes in the ICH brain are described. Finally, the clinical and translational implications of microglial polarization in ICH are presented, including the evidence that therapeutic approaches aimed at modulating microglial function might mitigate ICH injury and improve brain repair.
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Affiliation(s)
- Xi Lan
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, 720 Rutland Avenue, Ross Building 370B, Baltimore, Maryland 21205, USA
| | - Xiaoning Han
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, 720 Rutland Avenue, Ross Building 370B, Baltimore, Maryland 21205, USA
| | - Qian Li
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, 720 Rutland Avenue, Ross Building 370B, Baltimore, Maryland 21205, USA
| | - Qing-Wu Yang
- Department of Neurology, Xinqiao Hospital, Third Military Medical University, 183 Xinqiao Main Street, Shapingba District, Chongqing 400037, China
| | - Jian Wang
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, 720 Rutland Avenue, Ross Building 370B, Baltimore, Maryland 21205, USA
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1020
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Mondelli V, Vernon AC, Turkheimer F, Dazzan P, Pariante CM. Brain microglia in psychiatric disorders. Lancet Psychiatry 2017; 4:563-572. [PMID: 28454915 DOI: 10.1016/s2215-0366(17)30101-3] [Citation(s) in RCA: 167] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 01/30/2017] [Accepted: 01/31/2017] [Indexed: 12/30/2022]
Abstract
The role of immune activation in psychiatric disorders has attracted considerable attention over the past two decades, contributing to the rise of a new era for psychiatry. Microglia, the macrophages of the brain, are progressively becoming the main focus of the research in this field. In this Review, we assess the literature on microglia activation across different psychiatric disorders, including post-mortem and in-vivo studies in humans and experimental studies in animals. Although microglia activation has been noted in all types of psychiatric disorder, no association was seen with specific diagnostic categories. Furthermore, the findings from these studies highlight that not all psychiatric patients have microglial activation. Therefore, the cause of the neuroinflammation in these cohorts and its implications are unclear. We discuss psychosocial stress as one of the main factors determining microglial activation in patients with psychiatric disorders, and explore the relevance of these findings for future treatment strategies.
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Affiliation(s)
- Valeria Mondelli
- Department of Psychological Medicine, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK; National Institute for Health Research Mental Health Biomedical Research Centre, South London and Maudsley NHS Foundation Trust and King's College London, London, UK.
| | - Anthony C Vernon
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK; MRC Centre for Neurodevelopmental Disorders, King's College London, London, UK
| | - Federico Turkheimer
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK; MRC Centre for Neurodevelopmental Disorders, King's College London, London, UK
| | - Paola Dazzan
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK; National Institute for Health Research Mental Health Biomedical Research Centre, South London and Maudsley NHS Foundation Trust and King's College London, London, UK
| | - Carmine M Pariante
- Department of Psychological Medicine, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK; National Institute for Health Research Mental Health Biomedical Research Centre, South London and Maudsley NHS Foundation Trust and King's College London, London, UK
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1021
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Donat CK, Scott G, Gentleman SM, Sastre M. Microglial Activation in Traumatic Brain Injury. Front Aging Neurosci 2017; 9:208. [PMID: 28701948 PMCID: PMC5487478 DOI: 10.3389/fnagi.2017.00208] [Citation(s) in RCA: 282] [Impact Index Per Article: 40.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Accepted: 06/12/2017] [Indexed: 12/15/2022] Open
Abstract
Microglia have a variety of functions in the brain, including synaptic pruning, CNS repair and mediating the immune response against peripheral infection. Microglia rapidly become activated in response to CNS damage. Depending on the nature of the stimulus, microglia can take a number of activation states, which correspond to altered microglia morphology, gene expression and function. It has been reported that early microglia activation following traumatic brain injury (TBI) may contribute to the restoration of homeostasis in the brain. On the other hand, if they remain chronically activated, such cells display a classically activated phenotype, releasing pro-inflammatory molecules, resulting in further tissue damage and contributing potentially to neurodegeneration. However, new evidence suggests that this classification is over-simplistic and the balance of activation states can vary at different points. In this article, we review the role of microglia in TBI, analyzing their distribution, morphology and functional phenotype over time in animal models and in humans. Animal studies have allowed genetic and pharmacological manipulations of microglia activation, in order to define their role. In addition, we describe investigations on the in vivo imaging of microglia using translocator protein (TSPO) PET and autoradiography, showing that microglial activation can occur in regions far remote from sites of focal injuries, in humans and animal models of TBI. Finally, we outline some novel potential therapeutic approaches that prime microglia/macrophages toward the beneficial restorative microglial phenotype after TBI.
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Affiliation(s)
| | | | | | - Magdalena Sastre
- Division of Brain Sciences, Department of Medicine, Imperial College LondonLondon, United Kingdom
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1022
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Arcuri C, Mecca C, Bianchi R, Giambanco I, Donato R. The Pathophysiological Role of Microglia in Dynamic Surveillance, Phagocytosis and Structural Remodeling of the Developing CNS. Front Mol Neurosci 2017; 10:191. [PMID: 28674485 PMCID: PMC5474494 DOI: 10.3389/fnmol.2017.00191] [Citation(s) in RCA: 164] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 05/30/2017] [Indexed: 12/13/2022] Open
Abstract
In vertebrates, during an early wave of hematopoiesis in the yolk sac between embryonic day E7.0 and E9.0, cells of mesodermal leaflet addressed to macrophage lineage enter in developing central nervous system (CNS) and originate the developing native microglial cells. Depending on the species, microglial cells represent 5–20% of glial cells resident in adult brain. Here, we briefly discuss some canonical functions of the microglia, i.e., cytokine secretion and functional transition from M1 to M2 phenotype. In addition, we review studies on the non-canonical functions of microglia such as regulation of phagocytosis, synaptic pruning, and sculpting postnatal neural circuits. In this latter context the contribution of microglia to some neurodevelopmental disorders is now well established. Nasu-Hakola (NHD) disease is considered a primary microgliopathy with alterations of the DNAX activation protein 12 (DAP12)-Triggering receptor expressed on myeloid cells 2 (TREM-2) signaling and removal of macromolecules and apoptotic cells followed by secondary microglia activation. In Rett syndrome Mecp2-/- microglia shows a substantial impairment of phagocytic ability, although the role of microglia is not yet clear. In a mouse model of Tourette syndrome (TS), microglia abnormalities have also been described, and deficient microglia-mediated neuroprotection is obvious. Here we review the role of microglial cells in neurodevelopmental disorders without inflammation and on the complex role of microglia in developing CNS.
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Affiliation(s)
- Cataldo Arcuri
- Department of Experimental Medicine, Centro Universitario per la Ricerca sulla Genomica Funzionale, Perugia Medical School, University of PerugiaPerugia, Italy
| | - Carmen Mecca
- Department of Experimental Medicine, Centro Universitario per la Ricerca sulla Genomica Funzionale, Perugia Medical School, University of PerugiaPerugia, Italy
| | - Roberta Bianchi
- Department of Experimental Medicine, Centro Universitario per la Ricerca sulla Genomica Funzionale, Perugia Medical School, University of PerugiaPerugia, Italy
| | - Ileana Giambanco
- Department of Experimental Medicine, Centro Universitario per la Ricerca sulla Genomica Funzionale, Perugia Medical School, University of PerugiaPerugia, Italy
| | - Rosario Donato
- Department of Experimental Medicine, Centro Universitario per la Ricerca sulla Genomica Funzionale, Perugia Medical School, University of PerugiaPerugia, Italy
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1023
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Wang J, Zhao H, Fan Z, Li G, Ma Q, Tao Z, Wang R, Feng J, Luo Y. Long Noncoding RNA H19 Promotes Neuroinflammation in Ischemic Stroke by Driving Histone Deacetylase 1-Dependent M1 Microglial Polarization. Stroke 2017. [PMID: 28630232 DOI: 10.1161/strokeaha.117.017387] [Citation(s) in RCA: 182] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
BACKGROUND AND PURPOSE Long noncoding RNA H19 is repressed after birth, but can be induced by hypoxia. We aim to investigate the impact on and underlying mechanism of H19 induction after ischemic stroke. METHODS Circulating H19 levels in stroke patients and mice subjected to middle cerebral artery occlusion were assessed using real-time polymerase chain reaction. H19 siRNA and histone deacetylase 1 (HDAC1) plasmid were used to knock down H19 and overexpress HDAC1, respectively. Microglial polarization and ischemic outcomes were assessed in middle cerebral artery occlusion mice and BV2 microglial cells subjected to oxygen-glucose deprivation. RESULTS Circulating H19 levels were significantly higher in stroke patients compared with healthy controls, indicating high diagnostic sensitivity and specificity. Moreover, plasma H19 levels showed a positive correlation with National Institute of Health Stroke Scale score and tumor necrosis factor-α levels. After middle cerebral artery occlusion in mice, H19 levels increased in plasma, white blood cells, and brain. Intracerebroventricular injection of H19 siRNA reduced infarct volume and brain edema, decreased tumor necrosis factor-α and interleukin-1β levels in brain tissue and plasma, and increased plasma interleukin-10 concentrations 24 hours poststroke. Additionally, H19 knockdown attenuated brain tissue loss and neurological deficits 14 days poststroke. BV2 cell-based experiments showed that H19 knockdown blocked oxygen-glucose deprivation-driven M1 microglial polarization, decreased production of tumor necrosis factor-α and CD11b, and increased the expression of Arg-1 and CD206. Furthermore, H19 knockdown reversed oxygen-glucose deprivation-induced upregulation of HDAC1 and downregulation of acetyl-histone H3 and acetyl-histone H4. In contrast, HDAC1 overexpression negated the effects of H19 knockdown. CONCLUSIONS Our findings indicate that H19 promotes neuroinflammation by driving HDAC1-dependent M1 microglial polarization, suggesting a novel H19-based diagnosis and therapy for ischemic stroke.
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Affiliation(s)
- Jue Wang
- From the Cerebrovascular Diseases Research Institute and Department of Neurology, Xuanwu Hospital of Capital Medical University, Beijing, China (J.W., H.Z., Z.F., G.L., Q.M., Z.T., R.W., Y.L.); Beijing Institute for Brain Disorders, China (Y.L.); and Department of Neurology, Shengjing Hospital, Affiliated Hospital of China Medical University, Shen Yang (J.W., J.F.)
| | - Haiping Zhao
- From the Cerebrovascular Diseases Research Institute and Department of Neurology, Xuanwu Hospital of Capital Medical University, Beijing, China (J.W., H.Z., Z.F., G.L., Q.M., Z.T., R.W., Y.L.); Beijing Institute for Brain Disorders, China (Y.L.); and Department of Neurology, Shengjing Hospital, Affiliated Hospital of China Medical University, Shen Yang (J.W., J.F.)
| | - Zhibin Fan
- From the Cerebrovascular Diseases Research Institute and Department of Neurology, Xuanwu Hospital of Capital Medical University, Beijing, China (J.W., H.Z., Z.F., G.L., Q.M., Z.T., R.W., Y.L.); Beijing Institute for Brain Disorders, China (Y.L.); and Department of Neurology, Shengjing Hospital, Affiliated Hospital of China Medical University, Shen Yang (J.W., J.F.)
| | - Guangwen Li
- From the Cerebrovascular Diseases Research Institute and Department of Neurology, Xuanwu Hospital of Capital Medical University, Beijing, China (J.W., H.Z., Z.F., G.L., Q.M., Z.T., R.W., Y.L.); Beijing Institute for Brain Disorders, China (Y.L.); and Department of Neurology, Shengjing Hospital, Affiliated Hospital of China Medical University, Shen Yang (J.W., J.F.)
| | - Qingfeng Ma
- From the Cerebrovascular Diseases Research Institute and Department of Neurology, Xuanwu Hospital of Capital Medical University, Beijing, China (J.W., H.Z., Z.F., G.L., Q.M., Z.T., R.W., Y.L.); Beijing Institute for Brain Disorders, China (Y.L.); and Department of Neurology, Shengjing Hospital, Affiliated Hospital of China Medical University, Shen Yang (J.W., J.F.)
| | - Zhen Tao
- From the Cerebrovascular Diseases Research Institute and Department of Neurology, Xuanwu Hospital of Capital Medical University, Beijing, China (J.W., H.Z., Z.F., G.L., Q.M., Z.T., R.W., Y.L.); Beijing Institute for Brain Disorders, China (Y.L.); and Department of Neurology, Shengjing Hospital, Affiliated Hospital of China Medical University, Shen Yang (J.W., J.F.)
| | - Rongliang Wang
- From the Cerebrovascular Diseases Research Institute and Department of Neurology, Xuanwu Hospital of Capital Medical University, Beijing, China (J.W., H.Z., Z.F., G.L., Q.M., Z.T., R.W., Y.L.); Beijing Institute for Brain Disorders, China (Y.L.); and Department of Neurology, Shengjing Hospital, Affiliated Hospital of China Medical University, Shen Yang (J.W., J.F.)
| | - Juan Feng
- From the Cerebrovascular Diseases Research Institute and Department of Neurology, Xuanwu Hospital of Capital Medical University, Beijing, China (J.W., H.Z., Z.F., G.L., Q.M., Z.T., R.W., Y.L.); Beijing Institute for Brain Disorders, China (Y.L.); and Department of Neurology, Shengjing Hospital, Affiliated Hospital of China Medical University, Shen Yang (J.W., J.F.)
| | - Yumin Luo
- From the Cerebrovascular Diseases Research Institute and Department of Neurology, Xuanwu Hospital of Capital Medical University, Beijing, China (J.W., H.Z., Z.F., G.L., Q.M., Z.T., R.W., Y.L.); Beijing Institute for Brain Disorders, China (Y.L.); and Department of Neurology, Shengjing Hospital, Affiliated Hospital of China Medical University, Shen Yang (J.W., J.F.).
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1024
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The Effect of Osteopontin on Microglia. BIOMED RESEARCH INTERNATIONAL 2017; 2017:1879437. [PMID: 28698867 PMCID: PMC5494082 DOI: 10.1155/2017/1879437] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 04/29/2017] [Accepted: 05/24/2017] [Indexed: 12/16/2022]
Abstract
Osteopontin (OPN) is a proinflammatory cytokine that can be secreted from many cells, including activated macrophages and T-lymphocytes, and is widely distributed in many tissues and cells. OPN, a key factor in tissue repairing and extracellular matrix remodeling after injury, is a constituent of the extracellular matrix of the central nervous system (CNS). Recently, the role of OPN in neurodegenerative diseases has gradually caused widespread concern. Microglia are resident macrophage-like immune cells in CNS and play a vital role in both physiological and pathological conditions, including restoring the integrity of the CNS and promoting the progression of neurodegenerative disorders. Microglia's major function is to maintain homeostasis and the normal function of the CNS, both during development and in response to CNS injury. Although the functional mechanism of OPN in CNS neurodegenerative diseases has yet to be fully elucidated, most studies suggest that OPN play a role in pathogenesis of neurodegenerative diseases or in neuroprotection by regulating the activation and function of microglia. Here, we summarize the functions of OPN on microglia in response to various stimulations in vitro and in vivo.
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1025
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Spittau B. Aging Microglia-Phenotypes, Functions and Implications for Age-Related Neurodegenerative Diseases. Front Aging Neurosci 2017; 9:194. [PMID: 28659790 PMCID: PMC5469878 DOI: 10.3389/fnagi.2017.00194] [Citation(s) in RCA: 160] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 05/30/2017] [Indexed: 12/23/2022] Open
Abstract
Aging of the central nervous system (CNS) is one of the major risk factors for the development of neurodegenerative pathologies such as Parkinson’s disease (PD) and Alzheimer’s disease (AD). The molecular mechanisms underlying the onset of AD and especially PD are not well understood. However, neuroinflammatory responses mediated by microglia as the resident immune cells of the CNS have been reported for both diseases. The unique nature and developmental origin of microglia causing microglial self-renewal and telomere shortening led to the hypothesis that these CNS-specific innate immune cells become senescent. Age-dependent and senescence-driven impairments of microglia functions and responses have been suggested to play essential roles during onset and progression of neurodegenerative diseases. This review article summarizes the current knowledge of microglia phenotypes and functions in the aging CNS and further discusses the implications of these age-dependent microglia changes for the development and progression of AD and PD as the most common neurodegenerative diseases.
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Affiliation(s)
- Björn Spittau
- Department of Molecular Embryology, Faculty of Medicine, Institute for Anatomy and Cell Biology, University of FreiburgFreiburg, Germany.,Institute of Anatomy, University of RostockRostock, Germany
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1026
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Salvi V, Sozio F, Sozzani S, Del Prete A. Role of Atypical Chemokine Receptors in Microglial Activation and Polarization. Front Aging Neurosci 2017; 9:148. [PMID: 28603493 PMCID: PMC5445112 DOI: 10.3389/fnagi.2017.00148] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Accepted: 05/02/2017] [Indexed: 01/07/2023] Open
Abstract
Inflammatory reactions occurring in the central nervous system (CNS), known as neuroinflammation, are key components of the pathogenic mechanisms underlying several neurological diseases. The chemokine system plays a crucial role in the recruitment and activation of immune and non-immune cells in the brain, as well as in the regulation of microglia phenotype and function. Chemokines belong to a heterogeneous family of chemotactic agonists that signal through the interaction with G protein-coupled receptors (GPCRs). Recently, a small subset of chemokine receptors, now identified as “atypical chemokine receptors” (ACKRs), has been described. These receptors lack classic GPCR signaling and chemotactic activity and are believed to limit inflammation through their ability to scavenge chemokines at the inflammatory sites. Recent studies have highlighted a role for ACKRs in neuroinflammation. However, in the CNS, the role of ACKRs seems to be more complex than the simple control of inflammation. For instance, CXCR7/ACKR3 was shown to control T cell trafficking through the regulation of CXCL12 internalization at CNS endothelial barriers. Furthermore, D6/ACKR2 KO mice were protected in a model of experimental autoimmune encephalomyelitis (EAE). D6/ACKR2 KO showed an abnormal accumulation of dendritic cells at the immunization and a subsequent impairment in T cell priming. Finally, CCRL2, an ACKR-related protein, was shown to play a role in the control of the resolution phase of EAE. Indeed, CCRL2 KO mice showed exacerbated, non-resolving disease with protracted inflammation and increased demyelination. This phenotype was associated with increased microglia and macrophage activation markers and imbalanced M1 vs. M2 polarization. This review will summarize the current knowledge on the role of the ACKRs in neuroinflammation with a particular attention to their role in microglial polarization and function.
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Affiliation(s)
- Valentina Salvi
- Department of Molecular and Translational Medicine, University of BresciaBrescia, Italy
| | - Francesca Sozio
- Department of Molecular and Translational Medicine, University of BresciaBrescia, Italy.,IRCCS-Humanitas Clinical and Research CenterRozzano-Milano, Italy
| | - Silvano Sozzani
- Department of Molecular and Translational Medicine, University of BresciaBrescia, Italy.,IRCCS-Humanitas Clinical and Research CenterRozzano-Milano, Italy
| | - Annalisa Del Prete
- Department of Molecular and Translational Medicine, University of BresciaBrescia, Italy.,IRCCS-Humanitas Clinical and Research CenterRozzano-Milano, Italy
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1027
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Microglial Interferon Signaling and White Matter. Neurochem Res 2017; 42:2625-2638. [PMID: 28540600 DOI: 10.1007/s11064-017-2307-8] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Revised: 05/14/2017] [Accepted: 05/18/2017] [Indexed: 01/17/2023]
Abstract
Microglia, the resident immune cells of the CNS, are primary regulators of the neuroimmune response to injury. Type I interferons (IFNs), including the IFNαs and IFNβ, are key cytokines in the innate immune system. Their activity is implicated in the regulation of microglial function both during development and in response to neuroinflammation, ischemia, and neurodegeneration. Data from numerous studies in multiple sclerosis (MS) and stroke suggest that type I IFNs can modulate the microglial phenotype, influence the overall neuroimmune milieu, regulate phagocytosis, and affect blood-brain barrier integrity. All of these IFN-induced effects result in numerous downstream consequences on white matter pathology and microglial reactivity. Dysregulation of IFN signaling in mouse models with genetic deficiency in ubiquitin specific protease 18 (USP18) leads to a severe neurological phenotype and neuropathological changes that include white matter microgliosis and pro-inflammatory gene expression in dystrophic microglia. A class of genetic disorders in humans, referred to as pseudo-TORCH syndrome (PTS) for the clinical resemblance to infection-induced TORCH syndrome, also show dysregulation of IFN signaling, which leads to severe neurological developmental disease. In these disorders, the excessive activation of IFN signaling during CNS development results in a destructive interferonopathy with similar induction of microglial dysfunction as seen in USP18 deficient mice. Other recent studies implicate "microgliopathies" more broadly in neurological disorders including Alzheimer's disease (AD) and MS, suggesting that microglia are a potential therapeutic target for disease prevention and/or treatment, with interferon signaling playing a key role in regulating the microglial phenotype.
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1028
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Kabba JA, Xu Y, Christian H, Ruan W, Chenai K, Xiang Y, Zhang L, Saavedra JM, Pang T. Microglia: Housekeeper of the Central Nervous System. Cell Mol Neurobiol 2017; 38:53-71. [PMID: 28534246 DOI: 10.1007/s10571-017-0504-2] [Citation(s) in RCA: 152] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 05/16/2017] [Indexed: 12/17/2022]
Abstract
Microglia, of myeloid origin, play fundamental roles in the control of immune responses and the maintenance of central nervous system homeostasis. These cells, just like peripheral macrophages, may be activated into M1 pro-inflammatory or M2 anti-inflammatory phenotypes by appropriate stimuli. Microglia do not respond in isolation, but form part of complex networks of cells influencing each other. This review addresses the complex interaction of microglia with each cell type in the brain: neurons, astrocytes, cerebrovascular endothelial cells, and oligodendrocytes. We also highlight the participation of microglia in the maintenance of homeostasis in the brain, and their roles in the development and progression of age-related neurodegenerative disorders.
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Affiliation(s)
- John Alimamy Kabba
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Drug Screening, Jiangsu Key Laboratory of Drug Discovery for Metabolic Diseases, Jiangsu Key Laboratory of Druggability of Biopharmaceuticals, China Pharmaceutical University, #24 Tong Jia Xiang Street, Nanjing, 210009, People's Republic of China
| | - Yazhou Xu
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Drug Screening, Jiangsu Key Laboratory of Drug Discovery for Metabolic Diseases, Jiangsu Key Laboratory of Druggability of Biopharmaceuticals, China Pharmaceutical University, #24 Tong Jia Xiang Street, Nanjing, 210009, People's Republic of China
| | - Handson Christian
- Department of Pharmacology, School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, People's Republic of China
| | - Wenchen Ruan
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Drug Screening, Jiangsu Key Laboratory of Drug Discovery for Metabolic Diseases, Jiangsu Key Laboratory of Druggability of Biopharmaceuticals, China Pharmaceutical University, #24 Tong Jia Xiang Street, Nanjing, 210009, People's Republic of China
| | - Kitchen Chenai
- School of Pharmacy, China Pharmaceutical University, Nanjing, 210009, People's Republic of China
| | - Yun Xiang
- Department of Laboratory Medicine, Wuhan Children's Hospital, Tongji Medical College, Huazhong University of Science & Technology, Wuhan, 430016, People's Republic of China
| | - Luyong Zhang
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Drug Screening, Jiangsu Key Laboratory of Drug Discovery for Metabolic Diseases, Jiangsu Key Laboratory of Druggability of Biopharmaceuticals, China Pharmaceutical University, #24 Tong Jia Xiang Street, Nanjing, 210009, People's Republic of China
| | - Juan M Saavedra
- Department of Pharmacology and Physiology, Georgetown University Medical Center, Washington DC, 20057, USA
| | - Tao Pang
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Drug Screening, Jiangsu Key Laboratory of Drug Discovery for Metabolic Diseases, Jiangsu Key Laboratory of Druggability of Biopharmaceuticals, China Pharmaceutical University, #24 Tong Jia Xiang Street, Nanjing, 210009, People's Republic of China. .,Department of Pharmacology and Physiology, Georgetown University Medical Center, Washington DC, 20057, USA.
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1029
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Kata D, Földesi I, Feher LZ, Hackler L, Puskas LG, Gulya K. A novel pleiotropic effect of aspirin: Beneficial regulation of pro- and anti-inflammatory mechanisms in microglial cells. Brain Res Bull 2017; 132:61-74. [PMID: 28528204 DOI: 10.1016/j.brainresbull.2017.05.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2016] [Revised: 04/27/2017] [Accepted: 05/12/2017] [Indexed: 02/07/2023]
Abstract
Aspirin, one of the most widely used non-steroidal anti-inflammatory drugs, has extensively studied effects on the cardiovascular system. To reveal further pleiotropic, beneficial effects of aspirin on a number of pro- and anti-inflammatory microglial mechanisms, we performed morphometric and functional studies relating to phagocytosis, pro- and anti-inflammatory cytokine production (IL-1β, tumor necrosis factor-α (TNF-α) and IL-10, respectively) and analyzed the expression of a number of inflammation-related genes, including those related to the above functions, in pure microglial cells. We examined the effects of aspirin (0.1mM and 1mM) in unchallenged (control) and bacterial lipopolysaccharide (LPS)-challenged secondary microglial cultures. Aspirin affected microglial morphology and functions in a dose-dependent manner as it inhibited LPS-elicited microglial activation by promoting ramification and the inhibition of phagocytosis in both concentrations. Remarkably, aspirin strongly reduced the pro-inflammatory IL-1β and TNF-α production, while it increased the anti-inflammatory IL-10 level in LPS-challenged cells. Moreover, aspirin differentially regulated the expression of a number of inflammation-related genes as it downregulated such pro-inflammatory genes as Nos2, Kng1, IL1β, Ptgs2 or Ccr1, while it upregulated some anti-inflammatory genes such as IL10, Csf2, Cxcl1, Ccl5 or Tgfb1. Thus, the use of aspirin could be beneficial for the prophylaxis of certain neurodegenerative disorders as it effectively ameliorates inflammation in the brain.
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Affiliation(s)
- Diana Kata
- Department of Cell Biology and Molecular Medicine, University of Szeged, Szeged, Hungary.
| | - Imre Földesi
- Department of Laboratory Medicine, University of Szeged, Szeged, Hungary.
| | | | | | | | - Karoly Gulya
- Department of Cell Biology and Molecular Medicine, University of Szeged, Szeged, Hungary.
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1030
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Song GJ, Suk K. Pharmacological Modulation of Functional Phenotypes of Microglia in Neurodegenerative Diseases. Front Aging Neurosci 2017; 9:139. [PMID: 28555105 PMCID: PMC5430023 DOI: 10.3389/fnagi.2017.00139] [Citation(s) in RCA: 133] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Accepted: 04/25/2017] [Indexed: 01/06/2023] Open
Abstract
Microglia are the resident innate immune cells of the central nervous system that mediate brain homeostasis maintenance. Microglia-mediated neuroinflammation is a hallmark shared by various neurodegenerative diseases, including Alzheimer’s disease, Parkinson’s disease, and multiple sclerosis. Numerous studies have shown microglial activation phenotypes to be heterogeneous; however, these microglial phenotypes can largely be categorized as being either M1 or M2 type. Although the specific classification of M1 and M2 functionally polarized microglia remains a topic for debate, the use of functional modulators of microglial phenotypes as potential therapeutic approaches for the treatment of neurodegenerative diseases has garnered considerable attention. This review discusses M1 and M2 microglial phenotypes and their relevance in neurodegenerative disease models, as described in recent literature. The modulation of microglial polarization toward the M2 phenotype may lead to development of future therapeutic and preventive strategies for neuroinflammatory and neurodegenerative diseases. Thus, we focus on recent studies of microglial polarization modulators, with a particular emphasis on the small-molecule compounds and their intracellular target proteins.
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Affiliation(s)
- Gyun Jee Song
- BK21 Plus KNU Biomedical Convergence Program, Department of Pharmacology, Brain Science & Engineering Institute, School of Medicine, Kyungpook National UniversityDaegu, South Korea
| | - Kyoungho Suk
- BK21 Plus KNU Biomedical Convergence Program, Department of Pharmacology, Brain Science & Engineering Institute, School of Medicine, Kyungpook National UniversityDaegu, South Korea
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1031
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Mazaheri F, Snaidero N, Kleinberger G, Madore C, Daria A, Werner G, Krasemann S, Capell A, Trümbach D, Wurst W, Brunner B, Bultmann S, Tahirovic S, Kerschensteiner M, Misgeld T, Butovsky O, Haass C. TREM2 deficiency impairs chemotaxis and microglial responses to neuronal injury. EMBO Rep 2017; 18:1186-1198. [PMID: 28483841 DOI: 10.15252/embr.201743922] [Citation(s) in RCA: 226] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 03/27/2017] [Accepted: 03/31/2017] [Indexed: 12/20/2022] Open
Abstract
Sequence variations in the triggering receptor expressed on myeloid cells 2 (TREM2) have been linked to an increased risk for neurodegenerative disorders such as Alzheimer's disease and frontotemporal lobar degeneration. In the brain, TREM2 is predominantly expressed in microglia. Several disease-associated TREM2 variants result in a loss of function by reducing microglial phagocytosis, impairing lipid sensing, preventing binding of lipoproteins and affecting shielding of amyloid plaques. We here investigate the consequences of TREM2 loss of function on the microglia transcriptome. Among the differentially expressed messenger RNAs in wild-type and Trem2-/- microglia, gene clusters are identified which represent gene functions in chemotaxis, migration and mobility. Functional analyses confirm that loss of TREM2 impairs appropriate microglial responses to injury and signals that normally evoke chemotaxis on multiple levels. In an ex vivo organotypic brain slice assay, absence of TREM2 reduces the distance migrated by microglia. Moreover, migration towards defined chemo-attractants is reduced upon ablation of TREM2 and can be rescued by TREM2 re-expression. In vivo, microglia lacking TREM2 migrate less towards injected apoptotic neurons, and outgrowth of microglial processes towards sites of laser-induced focal CNS damage in the somatosensory cortex is slowed. The apparent lack of chemotactic stimulation upon depletion of TREM2 is consistent with a stable expression profile of genes characterizing the homoeostatic signature of microglia.
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Affiliation(s)
- Fargol Mazaheri
- German Center for Neurodegenerative Diseases (DZNE) Munich, Munich, Germany
| | - Nicolas Snaidero
- Institute of Neuronal Cell Biology, Technical University Munich, Munich, Germany.,Institute for Clinical Neuroimmunology, Biomedical Center (BMC) and University Hospital, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Gernot Kleinberger
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.,Biomedical Center (BMC), Biochemistry, Ludwig-Maximilians Universität München, Munich, Germany
| | - Charlotte Madore
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Anna Daria
- Biomedical Center (BMC), Biochemistry, Ludwig-Maximilians Universität München, Munich, Germany
| | - Georg Werner
- Biomedical Center (BMC), Biochemistry, Ludwig-Maximilians Universität München, Munich, Germany
| | - Susanne Krasemann
- Institute for Neuropathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Anja Capell
- Biomedical Center (BMC), Biochemistry, Ludwig-Maximilians Universität München, Munich, Germany
| | - Dietrich Trümbach
- Institute of Developmental Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Wolfgang Wurst
- German Center for Neurodegenerative Diseases (DZNE) Munich, Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.,Institute of Developmental Genetics, Helmholtz Zentrum München, Neuherberg, Germany.,Developmental Genetics, Technical University Munich-Weihenstephan, Neuherberg, Germany
| | - Bettina Brunner
- German Center for Neurodegenerative Diseases (DZNE) Munich, Munich, Germany
| | - Sebastian Bultmann
- Department of Biology and Center for Integrated Protein Science Munich (CIPSM), Ludwig Maximilians-Universität München, Munich, Germany
| | - Sabina Tahirovic
- German Center for Neurodegenerative Diseases (DZNE) Munich, Munich, Germany
| | - Martin Kerschensteiner
- Institute for Clinical Neuroimmunology, Biomedical Center (BMC) and University Hospital, Ludwig-Maximilians-Universität München, Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Thomas Misgeld
- German Center for Neurodegenerative Diseases (DZNE) Munich, Munich, Germany.,Institute of Neuronal Cell Biology, Technical University Munich, Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Oleg Butovsky
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Christian Haass
- German Center for Neurodegenerative Diseases (DZNE) Munich, Munich, Germany .,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.,Biomedical Center (BMC), Biochemistry, Ludwig-Maximilians Universität München, Munich, Germany
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1032
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Cerami C, Iaccarino L, Perani D. Molecular Imaging of Neuroinflammation in Neurodegenerative Dementias: The Role of In Vivo PET Imaging. Int J Mol Sci 2017; 18:ijms18050993. [PMID: 28475165 PMCID: PMC5454906 DOI: 10.3390/ijms18050993] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Revised: 04/14/2017] [Accepted: 04/18/2017] [Indexed: 11/16/2022] Open
Abstract
Neurodegeneration elicits neuroinflammatory responses to kill pathogens, clear debris and support tissue repair. Neuroinflammation is a dynamic biological response characterized by the recruitment of innate and adaptive immune system cells in the site of tissue damage. Resident microglia and infiltrating immune cells partake in the restoration of central nervous system homeostasis. Nevertheless, their activation may shift to chronic and aggressive responses, which jeopardize neuron survival and may contribute to the disease process itself. Positron Emission Tomography (PET) molecular imaging represents a unique tool contributing to in vivo investigating of neuroinflammatory processes in patients. In the present review, we first provide an overview on the molecular basis of neuroinflammation in neurodegenerative diseases with emphasis on microglia activation, astrocytosis and the molecular targets for PET imaging. Then, we review the state-of-the-art of in vivo PET imaging for neuroinflammation in dementia conditions associated with different proteinopathies, such as Alzheimer’s disease, frontotemporal lobar degeneration and Parkinsonian spectrum.
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Affiliation(s)
- Chiara Cerami
- Clinical Neuroscience Department, San Raffaele Turro Hospital, Milan 20121-20162, Italy.
- Division of Neuroscience, San Raffaele Scientific Institute, Milan 20121-20162, Italy.
| | - Leonardo Iaccarino
- Division of Neuroscience, San Raffaele Scientific Institute, Milan 20121-20162, Italy.
- Faculty of Psychology and Molecular Medicine Doctoral Course, Vita-Salute San Raffaele University, Milan 20121-20162, Italy.
| | - Daniela Perani
- Division of Neuroscience, San Raffaele Scientific Institute, Milan 20121-20162, Italy.
- Faculty of Psychology and Molecular Medicine Doctoral Course, Vita-Salute San Raffaele University, Milan 20121-20162, Italy.
- Nuclear Medicine Unit, San Raffaele Hospital, Milan 20121-20162, Italy.
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1033
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Iaccarino L, Moresco RM, Presotto L, Bugiani O, Iannaccone S, Giaccone G, Tagliavini F, Perani D. An In Vivo 11C-(R)-PK11195 PET and In Vitro Pathology Study of Microglia Activation in Creutzfeldt-Jakob Disease. Mol Neurobiol 2017; 55:2856-2868. [PMID: 28455699 DOI: 10.1007/s12035-017-0522-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Accepted: 04/06/2017] [Indexed: 01/08/2023]
Abstract
Microgliosis is part of the immunobiology of Creutzfeldt-Jakob disease (CJD). This is the first report using 11C-(R)-PK11195 PET imaging in vivo to measure 18 kDa translocator protein (TSPO) expression, indexing microglia activation, in symptomatic CJD patients, followed by a postmortem neuropathology comparison. One genetic CJD (gCJD) patient, two sporadic CJD (sCJD) patients, one variant CJD (vCJD) patient (mean ± SD age, 47.50 ± 15.95 years), and nine healthy controls (mean ± SD age, 44.00 ± 11.10 years) were included in the study. TSPO binding potentials were estimated using clustering and parametric analyses of reference regions. Statistical comparisons were run at the regional and at the voxel-wise levels. Postmortem evaluation measured scrapie prion protein (PrPSc) immunoreactivity, neuronal loss, spongiosis, astrogliosis, and microgliosis. 11C-(R)-PK11195-PET showed a significant TSPO overexpression at the cortical level in the two sCJD patients, as well as thalamic and cerebellar involvement; very limited parieto-occipital activation in the gCJD case; and significant increases at the subcortical level in the thalamus, basal ganglia, and midbrain and in the cerebellum in the vCJD brain. Along with misfolded prion deposits, neuropathology in all patients revealed neuronal loss, spongiosis and astrogliosis, and a diffuse cerebral and cerebellar microgliosis which was particularly dense in thalamic and basal ganglia structures in the vCJD brain. These findings confirm significant microgliosis in CJD, which was variably modulated in vivo and more diffuse at postmortem evaluation. Thus, TSPO overexpression in microglia activation, topography, and extent can vary in CJD subtypes, as shown in vivo, possibly related to the response to fast apoptotic processes, but reaches a large amount at the final disease course.
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Affiliation(s)
- Leonardo Iaccarino
- Vita-Salute San Raffaele University, Via Olgettina 58, 20132, Milan, Italy.,In Vivo Human Molecular and Structural Neuroimaging Unit, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Via Olgettina 58, 20132, Milan, Italy
| | - Rosa Maria Moresco
- Nuclear Medicine Unit, IRCCS San Raffaele Hospital, Via Olgettina 60, 20132, Milan, Italy.,IBFM-CNR, Via F.lli Cervi 93, Segrate, 20090, Milan, Italy.,Department of Health Sciences, University of Milan Bicocca, Piazza dell'Ateneo Nuovo, 1, 20126, Milan, Italy
| | - Luca Presotto
- In Vivo Human Molecular and Structural Neuroimaging Unit, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Via Olgettina 58, 20132, Milan, Italy.,Nuclear Medicine Unit, IRCCS San Raffaele Hospital, Via Olgettina 60, 20132, Milan, Italy
| | - Orso Bugiani
- IRCCS Foundation "Carlo Besta" Neurological Institute, Via Celoria 11, 20133, Milan, Italy
| | - Sandro Iannaccone
- Neurological Rehabilitation Unit, Clinical Neurosciences Department, IRCCS San Raffaele Hospital, Via Olgettina 60, 20132, Milan, Italy
| | - Giorgio Giaccone
- IRCCS Foundation "Carlo Besta" Neurological Institute, Via Celoria 11, 20133, Milan, Italy
| | - Fabrizio Tagliavini
- IRCCS Foundation "Carlo Besta" Neurological Institute, Via Celoria 11, 20133, Milan, Italy
| | - Daniela Perani
- Vita-Salute San Raffaele University, Via Olgettina 58, 20132, Milan, Italy. .,In Vivo Human Molecular and Structural Neuroimaging Unit, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Via Olgettina 58, 20132, Milan, Italy. .,Nuclear Medicine Unit, IRCCS San Raffaele Hospital, Via Olgettina 60, 20132, Milan, Italy.
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1034
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Liu YL, Chen WT, Lin YY, Lu PH, Hsieh SL, Cheng IHJ. Amelioration of amyloid-β-induced deficits by DcR3 in an Alzheimer's disease model. Mol Neurodegener 2017; 12:30. [PMID: 28438208 PMCID: PMC5402663 DOI: 10.1186/s13024-017-0173-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2016] [Accepted: 04/07/2017] [Indexed: 12/03/2022] Open
Abstract
Background Microglia mediate amyloid-beta peptide (Aβ)-induced neuroinflammation, which is one of the key events in the pathogenesis of Alzheimer’s disease (AD). Decoy receptor 3 (DcR3)/TNFRSF6B is a pleiotropic immunomodulator that promotes macrophage differentiation toward the M2 anti-inflammatory phenotype. Based on its role as an immunosupressor, we examined whether DcR3 could alleviate neuroinflammation and AD-like deficits in the central nervous system. Method We crossed human APP transgenic mice (line J20) with human DcR3 transgenic mice to generate wild-type, APP, DcR3, and APP/DcR3 mice for pathological analysis. The Morris water maze, fear conditioning test, open-field, and elevated-plus maze were used to access their cognitive behavioral changes. Furthermore, the pathological and immune profiles were examined by immunostaining, ELISA, Q-PCR, and IP. In vitro assays were designed to examine DcR3-mediated innate cytokine profile alteration and the potential protective mechanism. Results We reported that DcR3 ameliorates hippocampus-dependent memory deficits and reduces amyloid plaque deposition in APP transgenic mouse. The protective mechanism of DcR3 mediates through interacting with heparan sulfate proteoglycans and activating IL-4+YM1+ M2a-like microglia that reduces Aβ-induced proinflammatory cytokines and promotes phagocytosis ability of microglia. Conclusion The neuroprotective effect of DcR3 is mediated via modulating microglia activation into anti-inflammatory M2a phenotype, and upregulating DcR3 expression in the brain may be a potential therapeutic approach for AD. Electronic supplementary material The online version of this article (doi:10.1186/s13024-017-0173-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Yi-Ling Liu
- Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan
| | - Wei-Ting Chen
- Brain Research Center, National Yang-Ming University, Taipei, Taiwan
| | - Yu-Yi Lin
- Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan
| | - Po-Hung Lu
- Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan
| | - Shie-Liang Hsieh
- Genomics Research Center, Academia Sinica, Taipei, Taiwan. .,Institute of Clinical Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan. .,Institute of Microbiology and Immunology, National Yang-Ming University, Taipei, Taiwan. .,Department of Medical Research and Education, Taipei Veterans General Hospital, Taipei, Taiwan.
| | - Irene Han-Juo Cheng
- Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan. .,Brain Research Center, National Yang-Ming University, Taipei, Taiwan. .,Infection and Immunity Research Center, National Yang-Ming University, Taipei, Taiwan.
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1035
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Walter TJ, Crews FT. Microglial depletion alters the brain neuroimmune response to acute binge ethanol withdrawal. J Neuroinflammation 2017; 14:86. [PMID: 28427424 PMCID: PMC5439231 DOI: 10.1186/s12974-017-0856-z] [Citation(s) in RCA: 101] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Accepted: 03/28/2017] [Indexed: 01/15/2023] Open
Abstract
Background Recent studies have implicated microglia—the resident immune cells of the brain—in the pathophysiology of alcoholism. Indeed, post-mortem alcoholic brains show increased microglial markers and increased immune gene expression; however, the effects of ethanol on microglial functioning and how this impacts the brain remain unclear. In this present study, we investigate the effects of acute binge ethanol on microglia and how microglial depletion changes the brain neuroimmune response to acute binge ethanol withdrawal. Methods C57BL/6J mice were treated intragastrically with acute binge ethanol for time course and dose-response studies. Cultured mouse BV2 microglia-like cells were treated with ethanol in vitro for time course studies. Mice were also administered the colony stimulating factor 1 receptor (CSF1R) inhibitor PLX5622 to deplete microglia from the brain. These mice were subsequently treated with acute binge ethanol and sacrificed during withdrawal. Brain and BV2 mRNA were isolated and assessed using RT-PCR to examine expression of microglial and neuroimmune genes. Results Acute binge ethanol biphasically changed microglial (e.g., Iba1, CD68) gene expression, with initial decreases during intoxication and subsequent increases during withdrawal. Acute ethanol withdrawal dose dependently increased neuroimmune gene (e.g., TNFα, Ccl2, IL-1ra, IL-4) expression beginning at high doses. BV2 cells showed biphasic changes in pro-inflammatory (e.g., TNFα, Ccl2) gene expression following ethanol treatment in vitro. Administration of PLX5622 depleted microglia from the brains of mice. Although some neuroimmune genes were reduced by microglial depletion, many others were unchanged. Microglial depletion blunted pro-inflammatory (e.g., TNFα, Ccl2) gene expression and enhanced anti-inflammatory (e.g., IL-1ra, IL-4) gene expression during acute binge ethanol withdrawal. Conclusions These studies find acute binge ethanol withdrawal increases microglial and neuroimmune gene expression. Ethanol exposure also increases microglial pro-inflammatory gene expression in vitro. Furthermore, microglial depletion decreases expression of microglia-specific genes but has little effect on expression of many other neuroimmune signaling genes. Microglial depletion blunted the acute binge ethanol withdrawal induction of pro-inflammatory genes and enhanced induction of anti-inflammatory genes. These findings indicate microglia impact the brain response to acute binge ethanol withdrawal. Electronic supplementary material The online version of this article (doi:10.1186/s12974-017-0856-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- T Jordan Walter
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.,Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, Thurston-Bowles Building, Chapel Hill, NC, 27599, USA
| | - Fulton T Crews
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA. .,Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, Thurston-Bowles Building, Chapel Hill, NC, 27599, USA.
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1036
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Immunomodulation-accelerated neuronal regeneration following selective rod photoreceptor cell ablation in the zebrafish retina. Proc Natl Acad Sci U S A 2017; 114:E3719-E3728. [PMID: 28416692 DOI: 10.1073/pnas.1617721114] [Citation(s) in RCA: 97] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Müller glia (MG) function as inducible retinal stem cells in zebrafish, completely repairing the eye after damage. The innate immune system has recently been shown to promote tissue regeneration in which classic wound-healing responses predominate. However, regulatory roles for leukocytes during cellular regeneration-i.e., selective cell-loss paradigms akin to degenerative disease-are less well defined. To investigate possible roles innate immune cells play during retinal cell regeneration, we used intravital microscopy to visualize neutrophil, macrophage, and retinal microglia responses to induced rod photoreceptor apoptosis. Neutrophils displayed no reactivity to rod cell loss. Peripheral macrophage cells responded to rod cell loss, as evidenced by morphological transitions and increased migration, but did not enter the retina. Retinal microglia displayed multiple hallmarks of immune cell activation: increased migration, translocation to the photoreceptor cell layer, proliferation, and phagocytosis of dying cells. To test function during rod cell regeneration, we coablated microglia and rod cells or applied immune suppression and quantified the kinetics of (i) rod cell clearance, (ii) MG/progenitor cell proliferation, and (iii) rod cell replacement. Coablation and immune suppressants applied before cell loss caused delays in MG/progenitor proliferation rates and slowed the rate of rod cell replacement. Conversely, immune suppressants applied after cell loss had been initiated led to accelerated photoreceptor regeneration kinetics, possibly by promoting rapid resolution of an acute immune response. Our findings suggest that microglia control MG responsiveness to photoreceptor loss and support the development of immune-targeted therapeutic strategies for reversing cell loss associated with degenerative retinal conditions.
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1037
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Old Maids: Aging and Its Impact on Microglia Function. Int J Mol Sci 2017; 18:ijms18040769. [PMID: 28379162 PMCID: PMC5412353 DOI: 10.3390/ijms18040769] [Citation(s) in RCA: 145] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 03/27/2017] [Accepted: 03/28/2017] [Indexed: 12/20/2022] Open
Abstract
Microglia are highly active and vigilant housekeepers of the central nervous system that function to promote neuronal growth and activity. With advanced age, however, dysregulated inflammatory signaling and defects in phagocytosis impede their ability to perform the most essential of homeostatic functions, including immune surveillance and debris clearance. Microglial activation is one of the hallmarks of the aging brain and coincides with age-related neurodegeneration and cognitive decline. Age-associated microglial dysfunction leads to cellular senescence and can profoundly alter the response to sterile injuries and immune diseases, often resulting in maladaptive responses, chronic inflammation, and worsened outcomes after injury. Our knowledge of microglia aging and the factors that regulate age-related microglial dysfunction remain limited, as the majority of pre-clinical studies are performed in young animals, and human brain samples are difficult to obtain quickly post-mortem or in large numbers. This review outlines the impact of normal aging on microglial function, highlights the potential mechanisms underlying age-related changes in microglia, and discusses how aging can shape the recovery process following injury.
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1038
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Noristani HN, Gerber YN, Sabourin JC, Le Corre M, Lonjon N, Mestre-Frances N, Hirbec HE, Perrin FE. RNA-Seq Analysis of Microglia Reveals Time-Dependent Activation of Specific Genetic Programs following Spinal Cord Injury. Front Mol Neurosci 2017; 10:90. [PMID: 28420963 PMCID: PMC5376598 DOI: 10.3389/fnmol.2017.00090] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 03/15/2017] [Indexed: 12/18/2022] Open
Abstract
Neurons have inherent competence to regrow following injury, although not spontaneously. Spinal cord injury (SCI) induces a pronounced neuroinflammation driven by resident microglia and infiltrating peripheral macrophages. Microglia are the first reactive glial population after SCI and participate in recruitment of monocyte-derived macrophages to the lesion site. Both positive and negative influence of microglia and macrophages on axonal regeneration had been reported after SCI, raising the issue whether their response depends on time post-lesion or different lesion severity. We analyzed molecular alterations in microglia at several time-points after different SCI severities using RNA-sequencing. We demonstrate that activation of microglia is time-dependent post-injury but is independent of lesion severity. Early transcriptomic response of microglia after SCI involves proliferation and neuroprotection, which is then switched to neuroinflammation at later stages. Moreover, SCI induces an autologous microglial expression of astrocytic markers with over 6% of microglia expressing glial fibrillary acidic protein and vimentin from as early as 72 h post-lesion and up to 6 weeks after injury. We also identified the potential involvement of DNA damage and in particular tumor suppressor gene breast cancer susceptibility gene 1 (Brca1) in microglia after SCI. Finally, we established that BRCA1 protein is specifically expressed in non-human primate spinal microglia and is upregulated after SCI. Our data provide the first transcriptomic analysis of microglia at multiple stages after different SCI severities. Injury-induced microglia expression of astrocytic markers at RNA and protein levels demonstrates novel insights into microglia plasticity. Finally, increased microglia expression of BRCA1 in rodents and non-human primate model of SCI, suggests the involvement of oncogenic proteins after CNS lesion.
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Affiliation(s)
- Harun N Noristani
- MMDN, University of Montpellier; EPHE, Institut National de la Santé et de la Recherche Médicale U1198Montpellier, France.,Institut National de la Santé et de la Recherche Médicale U1051Montpellier, France
| | - Yannick N Gerber
- MMDN, University of Montpellier; EPHE, Institut National de la Santé et de la Recherche Médicale U1198Montpellier, France.,Institut National de la Santé et de la Recherche Médicale U1051Montpellier, France.,"Integrative Biology of Neurodegeneration", IKERBASQUE Basque Foundation for Science and Neuroscience Department, University of the Basque CountryBilbao, Spain
| | - Jean-Charles Sabourin
- "Integrative Biology of Neurodegeneration", IKERBASQUE Basque Foundation for Science and Neuroscience Department, University of the Basque CountryBilbao, Spain
| | - Marine Le Corre
- Institut National de la Santé et de la Recherche Médicale U1051Montpellier, France.,Department of Neurosurgery, Gui de Chauliac HospitalMontpellier, France
| | - Nicolas Lonjon
- MMDN, University of Montpellier; EPHE, Institut National de la Santé et de la Recherche Médicale U1198Montpellier, France.,Department of Neurosurgery, Gui de Chauliac HospitalMontpellier, France
| | - Nadine Mestre-Frances
- MMDN, University of Montpellier; EPHE, Institut National de la Santé et de la Recherche Médicale U1198Montpellier, France
| | - Hélène E Hirbec
- Institute for Functional Genomics, CNRS UMR5203, Institut National de la Santé et de la Recherche Médicale U1191Montpellier, France
| | - Florence E Perrin
- MMDN, University of Montpellier; EPHE, Institut National de la Santé et de la Recherche Médicale U1198Montpellier, France.,Institut National de la Santé et de la Recherche Médicale U1051Montpellier, France.,"Integrative Biology of Neurodegeneration", IKERBASQUE Basque Foundation for Science and Neuroscience Department, University of the Basque CountryBilbao, Spain
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1039
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Mangani D, Weller M, Roth P. The network of immunosuppressive pathways in glioblastoma. Biochem Pharmacol 2017; 130:1-9. [DOI: 10.1016/j.bcp.2016.12.011] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Accepted: 12/13/2016] [Indexed: 12/21/2022]
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1040
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Shobin E, Bowley MP, Estrada LI, Heyworth NC, Orczykowski ME, Eldridge SA, Calderazzo SM, Mortazavi F, Moore TL, Rosene DL. Microglia activation and phagocytosis: relationship with aging and cognitive impairment in the rhesus monkey. GeroScience 2017; 39:199-220. [PMID: 28238188 PMCID: PMC5411373 DOI: 10.1007/s11357-017-9965-y] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Accepted: 02/07/2017] [Indexed: 02/07/2023] Open
Abstract
While cognitive decline is observed in the normal aging monkey, neurons are not lost with age. Instead, frontal white matter is lost as myelin degenerates and both correlate with age-related cognitive decline. As age-related myelin damage increases, there should be an increase in clearance of damaged myelin by microglial phagocytosis. In this study, brains of behaviorally tested rhesus monkeys were assessed using unbiased stereology to quantify the density of activated microglia (LN3 antibody positive) and phagocytic microglia (galectin-3 (Gal-3) antibody positive) in three white matter regions: the corpus callosum, cingulum bundle (CGB), and frontal white matter (FWM). LN3 cell density was significantly increased in the CGB, whereas Gal-3 cell density was significantly increased in all regions. Increases in Gal-3 cell density in the FWM were associated with cognitive impairment. In the FWM of old animals, Gal-3-positive microglia were classified by morphological subtype as ramified, hypertrophic, or amoeboid. The densities of hypertrophic and amoeboid microglia significantly correlated with cognitive impairment. Finally, microglia were double-labeled with LN3 and Gal-3 showing that 91% of Gal-3 cells were also LN3 positive, thus expressing an "activated" phenotype. Furthermore, 15% of all double-labeled cells formed phagocytic cups. Overall, these results suggest that microglia become activated in white matter with age where the majority express a phagocytic phenotype. We hypothesize that age-related phagocytic activation of microglia is a response to accumulating myelin pathology. The association of Gal-3 in the FWM with cognitive impairment may reflect regional differences in damage or dysfunction of normal clearance mechanisms.
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Affiliation(s)
- Eli Shobin
- Department of Anatomy and Neurobiology, Boston University, Boston, MA, 02118, USA.
- Graduate Program for Neuroscience, Boston University, Boston, MA, 02118, USA.
| | - Michael P Bowley
- Department of Neurology, Massachusetts General Hospital, Boston, MA, 02144, USA
| | - Larissa I Estrada
- Department of Anatomy and Neurobiology, Boston University, Boston, MA, 02118, USA
- Department of Pharmacology and Experimental Therapeutics, Boston University, Boston, MA, 02118, USA
| | - Nadine C Heyworth
- Department of Anatomy and Neurobiology, Boston University, Boston, MA, 02118, USA
| | - Mary E Orczykowski
- Department of Anatomy and Neurobiology, Boston University, Boston, MA, 02118, USA
| | - Sherri A Eldridge
- Department of Anatomy and Neurobiology, Boston University, Boston, MA, 02118, USA
- Biology Department, University of Massachusetts Dartmouth, Dartmouth, MA, 02747, USA
| | | | - Farzad Mortazavi
- Department of Anatomy and Neurobiology, Boston University, Boston, MA, 02118, USA
| | - Tara L Moore
- Department of Anatomy and Neurobiology, Boston University, Boston, MA, 02118, USA
- Department of Neurology, Boston University School of Medicine, Boston, MA, 02118, USA
| | - Douglas L Rosene
- Department of Anatomy and Neurobiology, Boston University, Boston, MA, 02118, USA
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1041
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Barrett JP, Henry RJ, Villapol S, Stoica BA, Kumar A, Burns MP, Faden AI, Loane DJ. NOX2 deficiency alters macrophage phenotype through an IL-10/STAT3 dependent mechanism: implications for traumatic brain injury. J Neuroinflammation 2017; 14:65. [PMID: 28340575 PMCID: PMC5366128 DOI: 10.1186/s12974-017-0843-4] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 03/16/2017] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND NADPH oxidase (NOX2) is an enzyme system that generates reactive oxygen species (ROS) in microglia and macrophages. Excessive ROS production is linked with neuroinflammation and chronic neurodegeneration following traumatic brain injury (TBI). Redox signaling regulates macrophage/microglial phenotypic responses (pro-inflammatory versus anti-inflammatory), and NOX2 inhibition following moderate-to-severe TBI markedly reduces pro-inflammatory activation of macrophages/microglia resulting in concomitant increases in anti-inflammatory responses. Here, we report the signaling pathways that regulate NOX2-dependent macrophage/microglial phenotype switching in the TBI brain. METHODS Bone marrow-derived macrophages (BMDMs) prepared from wildtype (C57Bl/6) and NOX2 deficient (NOX2-/-) mice were treated with lipopolysaccharide (LPS; 10 ng/ml), interleukin-4 (IL-4; 10 ng/ml), or combined LPS/IL-4 to investigate signal transduction pathways associated with macrophage activation using western immunoblotting and qPCR analyses. Signaling pathways and activation markers were evaluated in ipsilateral cortical tissue obtained from adult male wildtype and NOX2-/- mice that received moderate-level controlled cortical impact (CCI). A neutralizing anti-IL-10 approach was used to determine the effects of IL-10 on NOX2-dependent transitions from pro- to anti-inflammatory activation states. RESULTS Using an LPS/IL-4-stimulated BMDM model that mimics the mixed pro- and anti-inflammatory responses observed in the injured cortex, we show that NOX2-/- significantly reduces STAT1 signaling and markers of pro-inflammatory activation. In addition, NOX2-/- BMDMs significantly increase anti-inflammatory marker expression; IL-10-mediated STAT3 signaling, but not STAT6 signaling, appears to be critical in regulating this anti-inflammatory response. Following moderate-level CCI, IL-10 is significantly increased in microglia/macrophages in the injured cortex of NOX2-/- mice. These changes are associated with increased STAT3 activation, but not STAT6 activation, and a robust anti-inflammatory response. Neutralization of IL-10 in NOX2-/- BMDMs or CCI mice blocks STAT3 activation and the anti-inflammatory response, thereby demonstrating a critical role for IL-10 in regulating NOX2-dependent transitions between pro- and anti-inflammatory activation states. CONCLUSIONS These studies indicate that following TBI NOX2 inhibition promotes a robust anti-inflammatory response in macrophages/microglia that is mediated by the IL-10/STAT3 signaling pathway. Thus, therapeutic interventions that inhibit macrophage/microglial NOX2 activity may improve TBI outcomes by not only limiting pro-inflammatory neurotoxic responses, but also enhancing IL-10-mediated anti-inflammatory responses that are neuroprotective.
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Affiliation(s)
- James P Barrett
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, 655 West Baltimore Street, #6-011, Baltimore, MD, 21201, USA
| | - Rebecca J Henry
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, 655 West Baltimore Street, #6-011, Baltimore, MD, 21201, USA
| | - Sonia Villapol
- Laboratory for Brain Injury and Dementia, Department of Neuroscience, Georgetown University, Washington, DC, USA
| | - Bogdan A Stoica
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, 655 West Baltimore Street, #6-011, Baltimore, MD, 21201, USA
| | - Alok Kumar
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, 655 West Baltimore Street, #6-011, Baltimore, MD, 21201, USA
| | - Mark P Burns
- Laboratory for Brain Injury and Dementia, Department of Neuroscience, Georgetown University, Washington, DC, USA
| | - Alan I Faden
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, 655 West Baltimore Street, #6-011, Baltimore, MD, 21201, USA
| | - David J Loane
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, 655 West Baltimore Street, #6-011, Baltimore, MD, 21201, USA.
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1042
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Datta G, Colasanti A, Kalk N, Owen D, Scott G, Rabiner EA, Gunn RN, Lingford-Hughes A, Malik O, Ciccarelli O, Nicholas R, Nei L, Battaglini M, Stefano ND, Matthews PM. 11C-PBR28 and 18F-PBR111 Detect White Matter Inflammatory Heterogeneity in Multiple Sclerosis. J Nucl Med 2017; 58:1477-1482. [DOI: 10.2967/jnumed.116.187161] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 02/28/2017] [Indexed: 11/16/2022] Open
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1043
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Laudati E, Currò D, Navarra P, Lisi L. Blockade of CCR5 receptor prevents M2 microglia phenotype in a microglia-glioma paradigm. Neurochem Int 2017; 108:100-108. [PMID: 28279751 DOI: 10.1016/j.neuint.2017.03.002] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Revised: 02/24/2017] [Accepted: 03/03/2017] [Indexed: 02/08/2023]
Abstract
Microglia express chemokines and their cognate receptors that were found to play important roles in many processes required for tumor development, such as tumor growth, proliferation, invasion, and angiogenesis. Among the chemokine receptor, CCR5 have been documented in different cancer models; in particular, CCR5 is highly expressed in human glioblastoma, where it is associated to poor prognosis. In the present study, we investigated the effect of CCR5 receptor blockade on a paradigm of microglia-glioma interaction; the CCR5 blocker maraviroc (MRV) was used as a pharmacological tool. We found that MVR is able to reduce the gene expression and function of the M2 markers ARG1 and IL-10 in presence of both basal glioma-released factors (C-CM) and activated glioma-released factors (LI-CM), but it up-regulates the M1 markers NO and IL-1β only if microglia is stimulated by LI-CM; the latter effect appears to be mediated by the inhibition of mTOR pathway. In addition, CCR5 blockade was associated to a significant reduction in microglia migration, an effect mediated through the inhibition of AKT pathway.
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Affiliation(s)
- Emilia Laudati
- Institute of Pharmacology, Catholic University Medical School, L.go F Vito 1, Rome, Italy
| | - Diego Currò
- Institute of Pharmacology, Catholic University Medical School, L.go F Vito 1, Rome, Italy
| | - Pierluigi Navarra
- Institute of Pharmacology, Catholic University Medical School, L.go F Vito 1, Rome, Italy.
| | - Lucia Lisi
- Institute of Pharmacology, Catholic University Medical School, L.go F Vito 1, Rome, Italy
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1044
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Expression of iNOS, CD163 and ARG-1 taken as M1 and M2 markers of microglial polarization in human glioblastoma and the surrounding normal parenchyma. Neurosci Lett 2017; 645:106-112. [PMID: 28259657 DOI: 10.1016/j.neulet.2017.02.076] [Citation(s) in RCA: 147] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Revised: 02/27/2017] [Accepted: 02/28/2017] [Indexed: 01/05/2023]
Abstract
Microglia and macrophages appear to be the most common cells in the GBM microenvironment. In the present study we investigated the status of macrophages/microglia activation in surgical specimens from 41 patients diagnosed with grade IV GBM. For each patient we analyzed both the center of tumor and the parenchyma surrounding the tumor. The specimens were stained for: i) IBA1, a 17-kDa EF hand protein specifically expressed in microglia/macrophages ii) CD163, a cell surface antigen associated with M2 phenotype; iii) iNOS, taken as a functional marker of M1 phenotype, and iv) ARG-I, taken as a functional marker of M2 phenotype. Staining was scored in a double-blinded score on a scale from 0 to 5. Our results suggest that CD163 expression is higher within the tumor than in surrounding periphery in both male and female patients; while iNOS is higher within the tumor in males, no significant difference was found for ARG-1. In addition, analyzing the data in TGCA database, we found that CD163 expression was significantly and inversely correlated with mean survival times, with average survival times ranging from 448days in patients having low expression, to 319 in mid, and 353 in patients with high CD163 expressing tumors. In contrast, no significant association was found between survival time and ARG-1 or iNOS expression.
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1045
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Sousa C, Biber K, Michelucci A. Cellular and Molecular Characterization of Microglia: A Unique Immune Cell Population. Front Immunol 2017; 8:198. [PMID: 28303137 PMCID: PMC5332364 DOI: 10.3389/fimmu.2017.00198] [Citation(s) in RCA: 98] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 02/09/2017] [Indexed: 12/26/2022] Open
Abstract
Microglia are essential for the development and function of the adult brain. Microglia arise from erythro-myeloid precursors in the yolk sac and populate the brain rudiment early during development. Unlike monocytes that are constantly renewed from bone marrow hematopoietic stem cells throughout life, resident microglia in the healthy brain persist during adulthood via constant self-renewal. Their ontogeny, together with the absence of turnover from the periphery and the singular environment of the central nervous system, make microglia a unique cell population. Supporting this notion, recent genome-wide transcriptional studies revealed specific gene expression profiles clearly distinct from other brain and peripheral immune cells. Here, we highlight the breakthrough studies that, over the last decades, helped elucidate microglial cell identity, ontogeny, and function. We describe the main techniques that have been used for this task and outline the crucial milestones that have been achieved to reach our actual knowledge of microglia. Furthermore, we give an overview of the “microgliome” that is currently emerging thanks to the constant progress in the modern profiling techniques.
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Affiliation(s)
- Carole Sousa
- NORLUX Neuro-Oncology Laboratory, Department of Oncology, Luxembourg Institute of Health, Luxembourg, Luxembourg; Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Esch-Belval, Luxembourg
| | - Knut Biber
- Department of Psychiatry and Psychotherapy, Section Molecular Psychiatry, University of Freiburg, Freiburg, Germany; Department of Neuroscience, Section Medical Physiology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Alessandro Michelucci
- NORLUX Neuro-Oncology Laboratory, Department of Oncology, Luxembourg Institute of Health, Luxembourg, Luxembourg; Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Esch-Belval, Luxembourg
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1046
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Bolós M, Perea JR, Avila J. Alzheimer's disease as an inflammatory disease. Biomol Concepts 2017; 8:37-43. [PMID: 28231054 DOI: 10.1515/bmc-2016-0029] [Citation(s) in RCA: 151] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 01/10/2017] [Indexed: 02/08/2023] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative condition characterized by the formation of amyloid-β plaques, aggregated and hyperphosphorylated tau protein, activated microglia and neuronal cell death, ultimately leading to progressive dementia. In this short review, we focus on neuroinflammation in AD. Specifically, we describe the participation of microglia, as well as other factors that may contribute to inflammation, in neurodegeneration.
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Affiliation(s)
- Marta Bolós
- Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Valderrebollo 5, E-28041-Madrid, Spain.,Centro de Biología Molecular "Severo Ochoa" CSIC-UAM, Nicolás Cabrera 1, E-28049-Madrid, Spain
| | - Juan Ramón Perea
- Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Valderrebollo 5, E-28041-Madrid, Spain.,Centro de Biología Molecular "Severo Ochoa" CSIC-UAM, Nicolás Cabrera 1, E-28049-Madrid, Spain
| | - Jesús Avila
- Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Valderrebollo 5, E-28041-Madrid, Spain.,Centro de Biología Molecular "Severo Ochoa" CSIC-UAM, Nicolás Cabrera 1, E-28049-Madrid, Spain
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1047
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Influence of extracellular zinc on M1 microglial activation. Sci Rep 2017; 7:43778. [PMID: 28240322 PMCID: PMC5327400 DOI: 10.1038/srep43778] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Accepted: 01/30/2017] [Indexed: 12/16/2022] Open
Abstract
Extracellular zinc, which is released from hippocampal neurons in response to brain ischaemia, triggers morphological changes in microglia. Under ischaemic conditions, microglia exhibit two opposite activation states (M1 and M2 activation), which may be further regulated by the microenvironment. We examined the role of extracellular zinc on M1 activation of microglia. Pre-treatment of microglia with 30–60 μM ZnCl2 resulted in dose-dependent increases in interleukin-1 beta (IL-1β), interleukin-6 (IL-6), and tumour necrosis factor-alpha (TNFα) secretion when M1 activation was induced by lipopolysaccharide administration. In contrast, the cell-permeable zinc chelator TPEN, the radical scavenger Trolox, and the P2X7 receptor antagonist A438079 suppressed the effects of zinc pre-treatment on microglia. Furthermore, endogenous zinc release was induced by cerebral ischaemia–reperfusion, resulting in increased expression of IL-1β, IL-6, TNFα, and the microglial M1 surface marker CD16/32, without hippocampal neuronal cell loss, in addition to impairments in object recognition memory. However, these effects were suppressed by the zinc chelator CaEDTA. These findings suggest that extracellular zinc may prime microglia to enhance production of pro-inflammatory cytokines via P2X7 receptor activation followed by reactive oxygen species generation in response to stimuli that trigger M1 activation, and that these inflammatory processes may result in deficits in object recognition memory.
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1048
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Thompson KK, Tsirka SE. The Diverse Roles of Microglia in the Neurodegenerative Aspects of Central Nervous System (CNS) Autoimmunity. Int J Mol Sci 2017; 18:ijms18030504. [PMID: 28245617 PMCID: PMC5372520 DOI: 10.3390/ijms18030504] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 02/21/2017] [Accepted: 02/21/2017] [Indexed: 02/07/2023] Open
Abstract
Autoimmune diseases of the central nervous system (CNS) involve inflammatory components and result in neurodegenerative processes. Microglia, the resident macrophages of the CNS, are the first responders after insults to the CNS and comprise a major link between the inflammation and neurodegeneration. Here, we will focus on the roles of microglia in two autoimmune diseases: the prevalent condition of multiple sclerosis (MS) and the much rarer Rasmussen’s encephalitis (RE). Although there is an abundance of evidence that microglia actively contribute to neuronal damage in pathological states such as MS and RE, there is also evidence of important reparative functions. As current research supports a more complex and diverse array of functions and phenotypes that microglia can assume, it is an especially interesting time to examine what is known about both the damaging and restorative roles that microglia can play in the inflammatory CNS setting. We will also discuss the pharmacological approaches to modulating microglia towards a more neuroprotective state.
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Affiliation(s)
- Kaitlyn K Thompson
- Molecular and Cellular Pharmacology Graduate Program, Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY 11794-8651, USA.
| | - Stella E Tsirka
- Molecular and Cellular Pharmacology Graduate Program, Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY 11794-8651, USA.
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1049
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Shan M, Lin S, Li S, Du Y, Zhao H, Hong H, Yang M, Yang X, Wu Y, Ren L, Peng J, Sun J, Zhou H, Su B. TIR-Domain-Containing Adapter-Inducing Interferon-β (TRIF) Is Essential for MPTP-Induced Dopaminergic Neuroprotection via Microglial Cell M1/M2 Modulation. Front Cell Neurosci 2017; 11:35. [PMID: 28275337 PMCID: PMC5319955 DOI: 10.3389/fncel.2017.00035] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 02/06/2017] [Indexed: 12/13/2022] Open
Abstract
Dynamic changes of two phenotypes of microglia, M1 and M2, are critically associated with the neurodegeneration of Parkinson's disease. However, the regulation of the M1/M2 paradigm is still unclear. In the MPTP induced neurodegeneration model, we examined the concentration of dopamine (DA) related metabolites and the survival of tyrosine hydroxylase (TH) positive cells in WT and Trif−/− mice. In in vitro experiments, MN9D cells were co-cultured with BV2 cells to mimic the animal experiments. Inhibition of TRIF aggravated TH+ cell loss, and DA-related metabolites decreased. TRIF inhibition was able to interrupt the microglial M1/M2 dynamic transformation. More BV2 cells were activated and migrated across the membrane of transwell plates by siTRIF treatment. Also, TRIF interruption inhibits the transformation of BV2 cells from the M1 to M2 phenotype which played a beneficial role in neuronal degenerative processes, and increased MN9D apoptosis. Moreover, MPP+ treatment decreases the (DAT) dopamine transporter and TH synthesis by MN9D. Taken together, the current results suggest that TRIF plays a key switch function in contributing to the microglial M1/M2 phenotype dynamic transformation. The interruption of TRIF may decrease the survival of MN9D cells as well as DAT and TH protein production. The current study sheds some light on the PD mechanism research by innate inflammation regulation.
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Affiliation(s)
- Minghui Shan
- Development and Regeneration Key Lab of Sichuan Province, Department of Pathology, Department of Anatomy and Histology and Embryology, Chengdu Medical CollegeChengdu, China; Department of Clinical Pathology, Nanyang Central HospitalNangyang, China
| | - Sen Lin
- Development and Regeneration Key Lab of Sichuan Province, Department of Pathology, Department of Anatomy and Histology and Embryology, Chengdu Medical College Chengdu, China
| | - Shurong Li
- Development and Regeneration Key Lab of Sichuan Province, Department of Pathology, Department of Anatomy and Histology and Embryology, Chengdu Medical CollegeChengdu, China; Research Center, Chengdu Medical College Infertility HospitalChengdu, China
| | - Yuchen Du
- Development and Regeneration Key Lab of Sichuan Province, Department of Pathology, Department of Anatomy and Histology and Embryology, Chengdu Medical College Chengdu, China
| | - Haixia Zhao
- Development and Regeneration Key Lab of Sichuan Province, Department of Pathology, Department of Anatomy and Histology and Embryology, Chengdu Medical College Chengdu, China
| | - Huarong Hong
- Development and Regeneration Key Lab of Sichuan Province, Department of Pathology, Department of Anatomy and Histology and Embryology, Chengdu Medical College Chengdu, China
| | - Ming Yang
- Development and Regeneration Key Lab of Sichuan Province, Department of Pathology, Department of Anatomy and Histology and Embryology, Chengdu Medical College Chengdu, China
| | - Xi Yang
- Development and Regeneration Key Lab of Sichuan Province, Department of Pathology, Department of Anatomy and Histology and Embryology, Chengdu Medical College Chengdu, China
| | - Yongmei Wu
- Development and Regeneration Key Lab of Sichuan Province, Department of Pathology, Department of Anatomy and Histology and Embryology, Chengdu Medical College Chengdu, China
| | - Liyi Ren
- Development and Regeneration Key Lab of Sichuan Province, Department of Pathology, Department of Anatomy and Histology and Embryology, Chengdu Medical College Chengdu, China
| | - Jiali Peng
- Development and Regeneration Key Lab of Sichuan Province, Department of Pathology, Department of Anatomy and Histology and Embryology, Chengdu Medical College Chengdu, China
| | - Jing Sun
- Development and Regeneration Key Lab of Sichuan Province, Department of Pathology, Department of Anatomy and Histology and Embryology, Chengdu Medical College Chengdu, China
| | - Hongli Zhou
- Development and Regeneration Key Lab of Sichuan Province, Department of Pathology, Department of Anatomy and Histology and Embryology, Chengdu Medical College Chengdu, China
| | - Bingyin Su
- Development and Regeneration Key Lab of Sichuan Province, Department of Pathology, Department of Anatomy and Histology and Embryology, Chengdu Medical CollegeChengdu, China; Research Center, Chengdu Medical College Infertility HospitalChengdu, China
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1050
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Michels M, Sonai B, Dal-Pizzol F. Polarization of microglia and its role in bacterial sepsis. J Neuroimmunol 2017; 303:90-98. [PMID: 28087076 DOI: 10.1016/j.jneuroim.2016.12.015] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 12/04/2016] [Accepted: 12/28/2016] [Indexed: 12/14/2022]
Abstract
Microglial polarization in response to brain inflammatory conditions is a crescent field in neuroscience. However, the effect of systemic inflammation, and specifically sepsis, is a relatively unexplored field that has great interest and relevance. Sepsis has been associated with both early and late harmful events of the central nervous system, suggesting that there is a close link between sepsis and neuroinflammation. During sepsis evolution it is supposed that microglial could exert both neurotoxic and repairing effects depending on the specific microglial phenotype assumed. In this context, here it was reviewed the role of microglial polarization during sepsis-associated brain dysfunction.
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Affiliation(s)
- Monique Michels
- Laboratory of Experimental Pathophysiology, Graduate Program in Health Sciences, University of Southern Santa Catarina, Av Universitária, 1105, Criciúma 88806000, SC, Brazil.
| | - Beatriz Sonai
- Laboratory of Experimental Pathophysiology, Graduate Program in Health Sciences, University of Southern Santa Catarina, Av Universitária, 1105, Criciúma 88806000, SC, Brazil.
| | - Felipe Dal-Pizzol
- Laboratory of Experimental Pathophysiology, Graduate Program in Health Sciences, University of Southern Santa Catarina, Av Universitária, 1105, Criciúma 88806000, SC, Brazil; Center of Excellence in Applied Neurosciences of Santa Catarina (NENASC), Graduate Program in Medical Sciences, Federal University of Santa Catarina (UFSC), Florianópolis, SC, Brazil.
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