101
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Interferon-γ Potentiates α-Synuclein-induced Neurotoxicity Linked to Toll-like Receptors 2 and 3 and Tumor Necrosis Factor-α in Murine Astrocytes. Mol Neurobiol 2019; 56:7664-7679. [PMID: 31098954 DOI: 10.1007/s12035-019-1567-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 03/15/2019] [Indexed: 10/26/2022]
Abstract
α-Synuclein (α-syn), a metabolite of neurons, induces glial activation and neuroinflammation and participates in pathogenesis of neurodegenerative diseases. This inflammatory response involves activation of toll-like receptors (TLRs) and its neurotoxic outcomes such as cytokine expression and release. However, regulatory role of cytokines on α-syn-induced neurotoxicity is still unclear. In this study, we used interferon (IFN)-γ to costimulate primary astrocytes with wild-type or A53T mutant α-syn, and evaluated inflammatory pathway activation. Four α-syn concentrations (0.5, 2, 8 and 20 μg/mL, 24 h) and four α-syn time-points (3, 12, 24 and 48 h, 2 μg/mL) were chosen to coincubate with one IFN-γ concentration (2 ng/mL). IFN-γ alone upregulated expressions of TLR3 and tumor necrosis factor (TNF)-α (mRNA level), and A53T mutant or wild-type α-syn alone activated the pathway components including TLR2, TLR3, nuclear factor-κB, TNF-α and interleukin (IL)-1β. Additive application of IFN-γ amplified this activation effect except for IL-1β at mRNA and protein levels or TNF-α release, displaying a synergistic effect of α-syn and IFN-γ. Blocking TLR2 other than TLR4 suppressed TLR3, TLR2 and TNF-α expressions induced by α-syn or plus IFN-γ, reflecting an interaction of TLR2 and TLR3 in TNF-α expression. These data collectively showed that IFN-γ potentiated α-syn stimulation and inflammatory outcomes via TLR2, TLR3 and TNF-α other than IL-1β in astrocytes, suggesting that involvement of IFN-γ in α-syn-induced innate immunity may be required for initiation and maintenance of glial activation, a novel neurotoxic mechanism underlying pathogenesis of neurodegenerative diseases. Graphical Abstract IFN-γ potentiates α-synuclein (A53T or wild-type)-induced innate immunity, involving expressions of TLR2, TLR3, NF-κB, and TNF-α, other than IL-1β. This effect is suppressed by blockage of TLR2 other than TLR4, reflecting an interaction of TLR2 and TLR3 in TNF-α expression. Thus, involvement of IFN-γ in α-syn-induced neurotoxicity may be required for initiation and maintenance of glial activation, a novel neurotoxic mechanism underlying pathogenesis of neurodegenerative diseases.
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102
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Microglial LOX-1/MAPKs/NF-κB positive loop promotes the vicious cycle of neuroinflammation and neural injury. Int Immunopharmacol 2019; 70:187-200. [DOI: 10.1016/j.intimp.2019.02.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 02/03/2019] [Accepted: 02/06/2019] [Indexed: 12/23/2022]
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103
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Chunchai T, Apaijai N, Keawtep P, Mantor D, Arinno A, Pratchayasakul W, Chattipakorn N, Chattipakorn SC. Testosterone deprivation intensifies cognitive decline in obese male rats via glial hyperactivity, increased oxidative stress, and apoptosis in both hippocampus and cortex. Acta Physiol (Oxf) 2019; 226:e13229. [PMID: 30506942 DOI: 10.1111/apha.13229] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 11/24/2018] [Accepted: 11/24/2018] [Indexed: 12/15/2022]
Abstract
AIM The study hypothesized that testosterone deprivation aggravates cognitive decline in obesity through increasing oxidative stress, glial activation, and apoptosis. METHODS Male Wistar rats (n = 24) were fed with either normal-diet (ND) or high-fat diet (HFD) for 24 weeks. At week 13, ND-fed rats and HFD-fed rats were randomly assigned to two subgroups to receive either a sham-operation or bilateral-orchiectomy (ORX). Rats were evaluated for metabolic parameters and cognition at 4, 8, and 12 weeks after the operation. At the end of protocol, the reactive oxygen species (ROS), glial morphology, and cell apoptosis were determined in hippocampus and cortex. RESULTS Both HFD-fed groups developed obese-insulin resistance, but ND-fed rats did not. HFD-fed rats with sham-operation showed cognitive decline, when compared to ND-fed rats with sham-operation at all time points. At 4- and 8-week after ORX, the cognitive impairment of ND-fed rats and both HFD-fed groups was not different. However, 12-week after ORX, cognitive decline and of glial hyperactivity of HFD-fed rats had the greatest increase among all groups. Hippocampal ROS levels and apoptotic cells in both HFD-fed groups were equally increased, but the cortical ROS levels and apoptotic cells of HFD-fed rats with ORX were the highest ones. CONCLUSIONS These findings suggest that testosterone deprivation aggravates cognitive decline in obesity via increasing oxidative stress, glial activity and apoptosis.
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Affiliation(s)
- Titikorn Chunchai
- Neurophysiology Unit, Cardiac Electrophysiology Research and Training Center, Faculty of Medicine Chiang Mai University Chiang Mai Thailand
- Cardiac Electrophysiology Unit, Department of Physiology Faculty of Medicine Chiang Mai University Chiang Mai Thailand
| | - Nattayaporn Apaijai
- Neurophysiology Unit, Cardiac Electrophysiology Research and Training Center, Faculty of Medicine Chiang Mai University Chiang Mai Thailand
- Cardiac Electrophysiology Unit, Department of Physiology Faculty of Medicine Chiang Mai University Chiang Mai Thailand
| | - Puntarik Keawtep
- Neurophysiology Unit, Cardiac Electrophysiology Research and Training Center, Faculty of Medicine Chiang Mai University Chiang Mai Thailand
- Cardiac Electrophysiology Unit, Department of Physiology Faculty of Medicine Chiang Mai University Chiang Mai Thailand
| | - Duangkamol Mantor
- Neurophysiology Unit, Cardiac Electrophysiology Research and Training Center, Faculty of Medicine Chiang Mai University Chiang Mai Thailand
- Cardiac Electrophysiology Unit, Department of Physiology Faculty of Medicine Chiang Mai University Chiang Mai Thailand
| | - Apiwan Arinno
- Neurophysiology Unit, Cardiac Electrophysiology Research and Training Center, Faculty of Medicine Chiang Mai University Chiang Mai Thailand
- Cardiac Electrophysiology Unit, Department of Physiology Faculty of Medicine Chiang Mai University Chiang Mai Thailand
| | - Wasana Pratchayasakul
- Neurophysiology Unit, Cardiac Electrophysiology Research and Training Center, Faculty of Medicine Chiang Mai University Chiang Mai Thailand
- Cardiac Electrophysiology Unit, Department of Physiology Faculty of Medicine Chiang Mai University Chiang Mai Thailand
| | - Nipon Chattipakorn
- Neurophysiology Unit, Cardiac Electrophysiology Research and Training Center, Faculty of Medicine Chiang Mai University Chiang Mai Thailand
- Cardiac Electrophysiology Unit, Department of Physiology Faculty of Medicine Chiang Mai University Chiang Mai Thailand
| | - Siriporn C. Chattipakorn
- Neurophysiology Unit, Cardiac Electrophysiology Research and Training Center, Faculty of Medicine Chiang Mai University Chiang Mai Thailand
- Department of Oral Biology and Diagnostic Sciences, Faculty of Dentistry Chiang Mai University Chiang Mai Thailand
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104
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Zhu C, Li B, Frontzek K, Liu Y, Aguzzi A. SARM1 deficiency up-regulates XAF1, promotes neuronal apoptosis, and accelerates prion disease. J Exp Med 2019; 216:743-756. [PMID: 30842236 PMCID: PMC6446871 DOI: 10.1084/jem.20171885] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 11/27/2018] [Accepted: 01/11/2019] [Indexed: 01/20/2023] Open
Abstract
Zhu et al. show that SARM1 deficiency selectively up-regulates XAF1 expression, which, in turn, promotes prion-induced neuronal death and accelerates prion progression. This study reveals a novel link between SARM1, XAF1, and associated neuronal apoptosis in prion disease. SARM1 (sterile α and HEAT/armadillo motif–containing protein) is a member of the MyD88 (myeloid differentiation primary response gene 88) family, which mediates innate immune responses. Because inactivation of SARM1 prevents various forms of axonal degeneration, we tested whether it might protect against prion-induced neurotoxicity. Instead, we found that SARM1 deficiency exacerbates the progression of prion pathogenesis. This deleterious effect was not due to SARM1-dependent modulation of prion-induced neuroinflammation, since microglial activation, astrogliosis, and brain cytokine profiles were not altered by SARM1 deficiency. Whole-transcriptome analyses indicated that SARM1 deficiency led to strong, selective overexpression of the pro-apoptotic gene XAF1 (X-linked inhibitor of apoptosis-associated factor 1). Consequently, the activity of pro-apoptotic caspases and neuronal death were enhanced in prion-infected SARM1−/− mice. These results point to an unexpected function of SARM1 as a regulator of prion-induced neurodegeneration and suggest that XAF1 might constitute a therapeutic target in prion disease.
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Affiliation(s)
- Caihong Zhu
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
| | - Bei Li
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
| | - Karl Frontzek
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
| | - Yingjun Liu
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
| | - Adriano Aguzzi
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
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105
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Priming of microglia with IFN-γ slows neuronal gamma oscillations in situ. Proc Natl Acad Sci U S A 2019; 116:4637-4642. [PMID: 30782788 DOI: 10.1073/pnas.1813562116] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Type II IFN (IFN-γ) is a proinflammatory T lymphocyte cytokine that serves in priming of microglia-resident CNS macrophages-during the complex microglial activation process under pathological conditions. Priming generally permits an exaggerated microglial response to a secondary inflammatory stimulus. The impact of primed microglia on physiological neuronal function in intact cortical tissue (in situ) is widely unknown, however. We explored the effects of chronic IFN-γ exposure on microglia in hippocampal slice cultures, i.e., postnatal parenchyma lacking leukocyte infiltration (adaptive immunity). We focused on fast neuronal network waves in the gamma-band (30-70 Hz). Such gamma oscillations are fundamental to higher brain functions, such as perception, attention, and memory, and are exquisitely sensitive to metabolic and oxidative stress. IFN-γ induced substantial morphological changes and cell population expansion in microglia as well as moderate up-regulation of activation markers, MHC-II, CD86, IL-6, and inducible nitric oxide synthase (iNOS), but not TNF-α. Cytoarchitecture and morphology of pyramidal neurons and parvalbumin-positive inhibitory interneurons were well-preserved. Notably, gamma oscillations showed a specific decline in frequency of up to 8 Hz, which was not mimicked by IFN-α or IL-17 exposure. The rhythm disturbance was caused by moderate microglial nitric oxide (NO) release demonstrated by pharmacological microglia depletion and iNOS inhibition. In conclusion, IFN-γ priming induces substantial proliferation and moderate activation of microglia that is capable of slowing neural information processing. This mechanism might contribute to cognitive impairment in chronic brain disease featuring elevated IFN-γ levels, blood-brain barrier leakage, and/or T cell infiltration, well before neurodegeneration occurs.
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106
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Pulido-Salgado M, Vidal-Taboada JM, Barriga GGD, Solà C, Saura J. RNA-Seq transcriptomic profiling of primary murine microglia treated with LPS or LPS + IFNγ. Sci Rep 2018; 8:16096. [PMID: 30382133 PMCID: PMC6208373 DOI: 10.1038/s41598-018-34412-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 10/17/2018] [Indexed: 01/20/2023] Open
Abstract
Microglia, the main resident immune cells in the CNS, are thought to participate in the pathogenesis of various neurological disorders. LPS and LPS + IFNγ are stimuli that are widely used to activate microglia. However, the transcriptomic profiles of microglia treated with LPS and LPS + IFNγ have not been properly compared. Here, we treated murine primary microglial cultures with LPS or LPS + IFNγ for 6 hours and then performed RNA-Sequencing. Gene expression patterns induced by the treatments were obtained by WGCNA and 11 different expression profiles were found, showing differential responses to LPS and LPS + IFNγ in many genes. Interestingly, a subset of genes involved in Parkinson’s, Alzheimer’s and Huntington’s disease were downregulated by both treatments. By DESeq analysis we found differentially upregulated and downregulated genes that confirmed LPS and LPS + IFNγ as inducers of microglial pro-inflammatory responses, but also highlighted their involvement in specific cell functions. In response to LPS, microglia tended to be more proliferative, pro-inflammatory and phagocytic; whereas LPS + IFNγ inhibited genes were involved in pain, cell division and, unexpectedly, production of some inflammatory mediators. In summary, this study provides a detailed description of the transcriptome of LPS- and LPS + IFNγ treated primary microglial cultures. It may be useful to determine whether these in vitro phenotypes resemble microglia in in vivo pathological conditions.
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Affiliation(s)
- Marta Pulido-Salgado
- Department of Biomedical Sciences, Biochemistry and Molecular Biology Unit, School of Medicine, University of Barcelona, IDIBAPS, Barcelona, Spain.,Institute of Neurosciences, University of Barcelona, Barcelona, Spain
| | - Jose M Vidal-Taboada
- Department of Biomedical Sciences, Biochemistry and Molecular Biology Unit, School of Medicine, University of Barcelona, IDIBAPS, Barcelona, Spain. .,Institute of Neurosciences, University of Barcelona, Barcelona, Spain. .,Peripheral Nervous System, Neuroscience Dept, VHIR- Vall d'Hebron Research Institute, Barcelona, Spain.
| | - Gerardo Garcia-Diaz Barriga
- Department of Biomedical Sciences, Histology Unit, School of Medicine, University of Barcelona, IDIBAPS, Barcelona, Spain.,Institute of Neurosciences, University of Barcelona, Barcelona, Spain
| | - Carme Solà
- Department of Cerebral Ischemia and Neurodegeneration, Institut d'Investigacions Biomèdiques de Barcelona, CSIC, IDIBAPS, Barcelona, Spain
| | - Josep Saura
- Department of Biomedical Sciences, Biochemistry and Molecular Biology Unit, School of Medicine, University of Barcelona, IDIBAPS, Barcelona, Spain. .,Institute of Neurosciences, University of Barcelona, Barcelona, Spain.
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107
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Han J, Zhu K, Zhang X, Harris RA. Enforced microglial depletion and repopulation as a promising strategy for the treatment of neurological disorders. Glia 2018; 67:217-231. [PMID: 30378163 PMCID: PMC6635749 DOI: 10.1002/glia.23529] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 08/17/2018] [Accepted: 08/22/2018] [Indexed: 01/18/2023]
Abstract
Microglia are prominent immune cells in the central nervous system (CNS) and are critical players in both neurological development and homeostasis, and in neurological diseases when dysfunctional. Our previous understanding of the phenotypes and functions of microglia has been greatly extended by a dearth of recent investigations. Distinct genetically defined subsets of microglia are now recognized to perform their own independent functions in specific conditions. The molecular profiling of single microglial cells indicates extensively heterogeneous reactions in different neurological disorders, resulting in multiple potentials for crosstalk with other kinds of CNS cells such as astrocytes and neurons. In settings of neurological diseases it could thus be prudent to establish effective cell‐based therapies by targeting entire microglial networks. Notably, activated microglial depletion through genetic targeting or pharmacological therapies within a suitable time window can stimulate replenishment of the CNS niche with new microglia. Additionally, enforced repopulation through provision of replacement cells also represents a potential means of exchanging dysfunctional with functional microglia. In each setting the newly repopulated microglia might have the potential to resolve ongoing neuroinflammation. In this review, we aim to summarize the most recent knowledge of microglia and to highlight microglial depletion and subsequent repopulation as a promising cell replacement therapy. Although glial cell replacement therapy is still in its infancy and future translational studies are still required, the approach is scientifically sound and provides new optimism for managing the neurotoxicity and neuroinflammation induced by activated microglia.
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Affiliation(s)
- Jinming Han
- Applied Immunology and Immunotherapy, Department of Clinical NeuroscienceKarolinska Institutet, Center for Molecular Medicine, Karolinska University Hospital at SolnaStockholmSweden
| | - Keying Zhu
- Applied Immunology and Immunotherapy, Department of Clinical NeuroscienceKarolinska Institutet, Center for Molecular Medicine, Karolinska University Hospital at SolnaStockholmSweden
| | - Xing‐Mei Zhang
- Applied Immunology and Immunotherapy, Department of Clinical NeuroscienceKarolinska Institutet, Center for Molecular Medicine, Karolinska University Hospital at SolnaStockholmSweden
| | - Robert A. Harris
- Applied Immunology and Immunotherapy, Department of Clinical NeuroscienceKarolinska Institutet, Center for Molecular Medicine, Karolinska University Hospital at SolnaStockholmSweden
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108
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Takeda A, Shinozaki Y, Kashiwagi K, Ohno N, Eto K, Wake H, Nabekura J, Koizumi S. Microglia mediate non-cell-autonomous cell death of retinal ganglion cells. Glia 2018; 66:2366-2384. [PMID: 30375063 DOI: 10.1002/glia.23475] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 05/23/2018] [Accepted: 05/28/2018] [Indexed: 12/22/2022]
Abstract
Excitotoxicity is well known in the neuronal death in the brain and is also linked to neuronal damages in the retina. Recent accumulating evidence show that microglia greatly affect excitotoxicity in the brain, but their roles in retina have received only limited attention. Here, we report that retinal excitotoxicity is mediated by microglia. To this end, we employed three discrete methods, that is, pharmacological inhibition of microglia by minocycline, pharmacological ablation by an antagonist for colony stimulating factor 1 receptor (PLX5622), and genetic ablation of microglia using Iba1-tTA::DTAtetO/tetO mice. Intravitreal injection of NMDA increased the number of apoptotic retinal ganglion cells (RGCs) followed by reduction in the number of RGCs. Although microglia did not respond to NMDA directly, they became reactive earlier than RGC damages. Inhibition or ablation of microglia protected RGCs against NMDA. We found up-regulation of proinflammatory cytokine genes including Il1b, Il6 and Tnfa, among which Tnfa was selectively blocked by minocycline. PLX5622 also suppressed Tnfa expression. Tumor necrosis factor α (TNFα) signals were restricted in microglia at very early followed by spreading into other cell types. TNFα up-regulation in microglia and other cells were significantly attenuated by minocycline and PLX5622, suggesting a central role of microglia for TNFα induction. Both inhibition of TNFα and knockdown of TNF receptor type 1 by siRNA protected RGCs against NMDA. Taken together, our data demonstrate that a phenotypic change of microglia into a neurotoxic one is a critical event for the NMDA-induced degeneration of RGCs, suggesting an importance of non-cell-autonomous mechanism in the retinal neuronal excitotoxicity.
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Affiliation(s)
- Akiko Takeda
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan
| | - Youichi Shinozaki
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan
| | - Kenji Kashiwagi
- Department of Ophthalmology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan
| | - Nobuhiko Ohno
- Division of Neurobiology and Bioinformatics, National Institute for Physiological Sciences (NIPS), Aichi, Japan.,Department of Anatomy, Jichi Medical University, Tochigi, Japan
| | - Kei Eto
- Division of Homeostatic Development, NIPS, Aichi, Japan
| | - Hiroaki Wake
- Division of Homeostatic Development, NIPS, Aichi, Japan.,Division of System Neuroscience, Graduate School of Medicine, Kobe University, Hyogo, Japan.,Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, Saitama, Japan
| | | | - Schuichi Koizumi
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan
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109
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Qin C, Liu Q, Hu ZW, Zhou LQ, Shang K, Bosco DB, Wu LJ, Tian DS, Wang W. Microglial TLR4-dependent autophagy induces ischemic white matter damage via STAT1/6 pathway. Theranostics 2018; 8:5434-5451. [PMID: 30555556 PMCID: PMC6276098 DOI: 10.7150/thno.27882] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 10/03/2018] [Indexed: 12/28/2022] Open
Abstract
Rationale: Ischemic white matter damage frequently results in myelin loss, accompanied with microglial activation. We previously found that directing microglia towards an anti-inflammatory phenotype provided a beneficial microenvironment and helped maintain white matter integrity during chronic cerebral hypoperfusion. However, the molecular mechanisms underlying microglial polarization remain elusive. Methods: Hypoperfusion induced white matter damage mice model and lipopolysaccharide (LPS) induced primary cultured microglia were established. Autophagy activation in microglia was detected both in vivo and in vitro by immunofluorescence, Western blot and electron microscopy. Autophagy inhibitors/agonist were administrated to investigate the role of autophagic process in modulating microglial phenotypes. Quantitative real time-polymerase chain reaction and Western blot were carried out to investigate the possible pathway. Results: We identified rapid accumulation of autophagosomes in primary cultured microglia exposed to LPS and within activated microglia during white matter ischemic damage. Autophagy inhibitors switched microglial function from pro-inflammatory to anti-inflammatory phenotype. Furthermore, we found TLR4, one of the major receptors binding LPS, was most highly expressed on microglia in corpus callosum during white matter ischemic damage, and TLR4 deficiency could mimic the phenomenon in microglial functional transformation, and exhibit a protective activity in chronic cerebral hypoperfusion. Whereas, the anti-inflammatory phenotype of microglia in TLR4 deficiency group was largely abolished by the activation of autophagic process. Finally, our transcriptional analysis confirmed that the up-regulation of STAT1 and down-regulation of STAT6 in microglia exposure to LPS could be reversed by autophagy inhibition. Conclusion: These results indicated that TLR4-dependent autophagy regulates microglial polarization and induces ischemic white matter damage via STAT1/6 pathway.
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110
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Greenhalgh AD, Zarruk JG, Healy LM, Baskar Jesudasan SJ, Jhelum P, Salmon CK, Formanek A, Russo MV, Antel JP, McGavern DB, McColl BW, David S. Peripherally derived macrophages modulate microglial function to reduce inflammation after CNS injury. PLoS Biol 2018; 16:e2005264. [PMID: 30332405 PMCID: PMC6205650 DOI: 10.1371/journal.pbio.2005264] [Citation(s) in RCA: 139] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Revised: 10/29/2018] [Accepted: 10/01/2018] [Indexed: 12/19/2022] Open
Abstract
Infiltrating monocyte-derived macrophages (MDMs) and resident microglia dominate central nervous system (CNS) injury sites. Differential roles for these cell populations after injury are beginning to be uncovered. Here, we show evidence that MDMs and microglia directly communicate with one another and differentially modulate each other's functions. Importantly, microglia-mediated phagocytosis and inflammation are suppressed by infiltrating macrophages. In the context of spinal cord injury (SCI), preventing such communication increases microglial activation and worsens functional recovery. We suggest that macrophages entering the CNS provide a regulatory mechanism that controls acute and long-term microglia-mediated inflammation, which may drive damage in a variety of CNS conditions.
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Affiliation(s)
- Andrew D. Greenhalgh
- Centre for Research in Neuroscience, The Research Institute of the McGill University Health Center, Quebec, Canada
- Laboratory of Nutrition and Integrated Neurobiology, UMR INRA 1286, University of Bordeaux, Bordeaux, France
| | - Juan G. Zarruk
- Centre for Research in Neuroscience, The Research Institute of the McGill University Health Center, Quebec, Canada
| | - Luke M. Healy
- Neuroimmunology Unit, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
| | - Sam J. Baskar Jesudasan
- Centre for Research in Neuroscience, The Research Institute of the McGill University Health Center, Quebec, Canada
| | - Priya Jhelum
- Centre for Research in Neuroscience, The Research Institute of the McGill University Health Center, Quebec, Canada
| | - Christopher K. Salmon
- Centre for Research in Neuroscience, The Research Institute of the McGill University Health Center, Quebec, Canada
| | - Albert Formanek
- Centre for Research in Neuroscience, The Research Institute of the McGill University Health Center, Quebec, Canada
| | - Matthew V. Russo
- Viral Immunology and Intravital Imaging Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Jack P. Antel
- Neuroimmunology Unit, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
| | - Dorian B. McGavern
- Viral Immunology and Intravital Imaging Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Barry W. McColl
- UK Dementia Research Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Samuel David
- Centre for Research in Neuroscience, The Research Institute of the McGill University Health Center, Quebec, Canada
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111
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Lee JY, Joo B, Nam JH, Nam HY, Lee W, Nam Y, Seo Y, Kang HJ, Cho HJ, Jang YP, Kim J, We YM, Koo JW, Hoe HS. An Aqueous Extract of Herbal Medicine ALWPs Enhances Cognitive Performance and Inhibits LPS-Induced Neuroinflammation via FAK/NF-κB Signaling Pathways. Front Aging Neurosci 2018; 10:269. [PMID: 30319390 PMCID: PMC6168635 DOI: 10.3389/fnagi.2018.00269] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Accepted: 08/22/2018] [Indexed: 12/11/2022] Open
Abstract
Recent studies have shown that Liuwei Dihuang pills (LWPs) can positively affect learning, memory and neurogenesis. However, the underlying molecular mechanisms are not understood. In the present study, we developed ALWPs, a mixture of Antler and LWPs, and investigated whether ALWPs can affect neuroinflammatory responses. We found that ALWPs (500 mg/ml) inhibited lipopolysaccharide (LPS)-induced proinflammatory cytokine IL-1β mRNA levels in BV2 microglial cells but not primary astrocytes. ALWPs significantly reduced LPS-induced cell-surface levels of TLR4 to alter neuroinflammation. An examination of the molecular mechanisms by which ALWPs regulate the LPS-induced proinflammatory response revealed that ALWPs significantly downregulated LPS-induced levels of FAK phosphorylation, suggesting that ALWPs modulate FAK signaling to alter LPS-induced IL-1β levels. In addition, treatment with ALWPs followed by LPS resulted in decreased levels of the transcription factor NF-κB in the nucleus compared with LPS alone. Moreover, ALWPs significantly suppressed LPS-induced BV2 microglial cell migration. To examine whether ALWPs modulate learning and memory in vivo, wild-type C57BL/6J mice were orally administered ALWPs (200 mg/kg) or PBS daily for 3 days, intraperitoneally injected (i.p.) with LPS (250 μg/kg) or PBS, and assessed in Y maze and NOR tests. We observed that oral administration of ALWPs to LPS-injected wild-type C57BL/6J mice significantly rescued short- and long-term memory. More importantly, oral administration of ALWPs to LPS-injected wild-type C57BL/6J mice significantly reduced microglial activation in the hippocampus and cortex. Taken together, our results suggest that ALWPs can suppress neuroinflammation-associated cognitive deficits and that ALWPs have potential as a drug for neuroinflammation/neurodegeneration-related diseases, including Alzheimer's disease (AD).
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Affiliation(s)
- Ju-Young Lee
- Department of Neural Development and Disease, Korea Brain Research Institute, Daegu, South Korea
| | - Bitna Joo
- Department of Neural Development and Disease, Korea Brain Research Institute, Daegu, South Korea
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science & Technology, Daegu, South Korea
| | - Jin Han Nam
- Department of Neural Development and Disease, Korea Brain Research Institute, Daegu, South Korea
| | - Hye Yeon Nam
- Department of Neural Development and Disease, Korea Brain Research Institute, Daegu, South Korea
| | - Wonil Lee
- Department of Neural Development and Disease, Korea Brain Research Institute, Daegu, South Korea
| | - Youngpyo Nam
- Department of Neural Development and Disease, Korea Brain Research Institute, Daegu, South Korea
| | - Yongtaek Seo
- Division of Pharmacology, College of Pharmacy, Kyung Hee University, Seoul, South Korea
| | - Hye-Jin Kang
- Department of Neural Development and Disease, Korea Brain Research Institute, Daegu, South Korea
| | - Hyun-Ji Cho
- Department of Neural Development and Disease, Korea Brain Research Institute, Daegu, South Korea
| | - Young Pyo Jang
- Division of Pharmacology, College of Pharmacy, Kyung Hee University, Seoul, South Korea
| | - Jeongyeon Kim
- Department of Neural Development and Disease, Korea Brain Research Institute, Daegu, South Korea
| | - Young-Man We
- College of Korean Medicine, Wonkwang University, Iksan, South Korea
- Oriental Medical Clinic Center, Hyoo Medical Clinic, Seoul, South Korea
| | - Ja Wook Koo
- Department of Neural Development and Disease, Korea Brain Research Institute, Daegu, South Korea
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science & Technology, Daegu, South Korea
| | - Hyang-Sook Hoe
- Department of Neural Development and Disease, Korea Brain Research Institute, Daegu, South Korea
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112
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Song WM, Colonna M. The identity and function of microglia in neurodegeneration. Nat Immunol 2018; 19:1048-1058. [DOI: 10.1038/s41590-018-0212-1] [Citation(s) in RCA: 165] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 08/21/2018] [Indexed: 12/11/2022]
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113
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Gong H, Su WJ, Cao ZY, Lian YJ, Peng W, Liu YZ, Zhang Y, Liu LL, Wu R, Wang B, Zhang T, Wang YX, Jiang CL. Hippocampal Mrp8/14 signaling plays a critical role in the manifestation of depressive-like behaviors in mice. J Neuroinflammation 2018; 15:252. [PMID: 30180864 PMCID: PMC6122683 DOI: 10.1186/s12974-018-1296-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 08/29/2018] [Indexed: 12/17/2022] Open
Abstract
Background Depression is one of the most common mental disorders characterized mainly by low mood and loss of interest or pleasure. About a third of patients with depression do not respond to classic antidepressant treatments. Recent evidence suggests that Mrp8/14 (myeloid-related protein 8/14) plays a crucial role in cognitive dysfunction and neuroinflammatory diseases, yet its role in mood regulation remains largely uninvestigated. In the present work, we explored the potential role of Mrp8/14 in the progression of depression. Methods After 4 weeks of chronic unpredictable mild stress (CUMS), depressive-like symptoms and Mrp8/14 were determined. To verify the effects of Mrp8/14 on depressive-like behaviors, the inhibitor TAK-242 and recombinant Mrp8/14 were used. Furthermore, the molecular mechanisms in Mrp8/14-induced behavioral and biological changes were examined in vivo and ex vivo. Results Four-week CUMS contributed to the development of depressive symptoms. Mrp8 and Mrp14 were upregulated in the hippocampus and serum after exposure to CUMS. Pharmacological inhibition of Mrp14 attenuated CUMS-induced TLR4/NF-κB signaling activation and depressive-like behaviors. Furthermore, central administration of recombinant Mrp8, Mrp14, and Mrp8/14 resulted in neuroinflammation and depressive-like behaviors. Mrp8/14-provoked proinflammatory effects and depressive-like behaviors were improved by pretreatment with a TLR4 inhibitor. Moreover, pharmacological inhibition of TLR4 reduced the release of nitric oxide and reactive oxygen species in Mrp8/14-activated BV2 microglia. Conclusions These data suggest that the hippocampal Mrp8/14-TLR4-mediated neuroinflammation contributes to the development of depressive-like behaviors. Targeting the Mrp8/14 may be a novel promising antidepressant approach. Electronic supplementary material The online version of this article (10.1186/s12974-018-1296-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Hong Gong
- Department of Stress Medicine, Faculty of Psychology and Mental Health, Second Military Medical University, Shanghai, 200433, People's Republic of China.,Hainan Branch of Chinese PLA General Hospital, Sanya, 572013, People's Republic of China
| | - Wen-Jun Su
- Department of Stress Medicine, Faculty of Psychology and Mental Health, Second Military Medical University, Shanghai, 200433, People's Republic of China
| | - Zhi-Yong Cao
- Department of Stress Medicine, Faculty of Psychology and Mental Health, Second Military Medical University, Shanghai, 200433, People's Republic of China.,Department of Psychiatry, The 102nd Hospital of PLA, Changzhou, 213003, People's Republic of China
| | - Yong-Jie Lian
- Department of Stress Medicine, Faculty of Psychology and Mental Health, Second Military Medical University, Shanghai, 200433, People's Republic of China
| | - Wei Peng
- Department of Stress Medicine, Faculty of Psychology and Mental Health, Second Military Medical University, Shanghai, 200433, People's Republic of China
| | - Yun-Zi Liu
- Department of Stress Medicine, Faculty of Psychology and Mental Health, Second Military Medical University, Shanghai, 200433, People's Republic of China
| | - Yi Zhang
- Department of Psychiatry, Faculty of Psychology and Mental Health, Second Military Medical University, Shanghai, 200433, People's Republic of China
| | - Lin-Lin Liu
- Department of Stress Medicine, Faculty of Psychology and Mental Health, Second Military Medical University, Shanghai, 200433, People's Republic of China
| | - Ran Wu
- Department of Stress Medicine, Faculty of Psychology and Mental Health, Second Military Medical University, Shanghai, 200433, People's Republic of China
| | - Bo Wang
- Department of Stress Medicine, Faculty of Psychology and Mental Health, Second Military Medical University, Shanghai, 200433, People's Republic of China
| | - Ting Zhang
- Department of Navy Medicine, Second Military Medical University, Shanghai, 200433, People's Republic of China
| | - Yun-Xia Wang
- Department of Stress Medicine, Faculty of Psychology and Mental Health, Second Military Medical University, Shanghai, 200433, People's Republic of China
| | - Chun-Lei Jiang
- Department of Stress Medicine, Faculty of Psychology and Mental Health, Second Military Medical University, Shanghai, 200433, People's Republic of China.
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Verma DK, Gupta S, Biswas J, Joshi N, Sivarama Raju K, Wahajuddin M, Singh S. Metabolic Enhancer Piracetam Attenuates the Translocation of Mitochondrion-Specific Proteins of Caspase-Independent Pathway, Poly [ADP-Ribose] Polymerase 1 Up-regulation and Oxidative DNA Fragmentation. Neurotox Res 2018; 34:198-219. [PMID: 29532444 DOI: 10.1007/s12640-018-9878-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 01/29/2018] [Accepted: 01/31/2018] [Indexed: 11/28/2022]
Abstract
Piracetam, a nootropic drug, has been clinically used for decades; however, its mechanism of action still remains enigmatic. The present study was undertaken to evaluate the role of mitochondrion-specific factors of caspase-independent pathway like apoptotic-inducing factor (AIF) and endonuclease-G (endo-G) in piracetam-induced neuroprotection. N2A cells treated with lipopolysaccharide (LPS) exhibited significant cytotoxicity, impaired mitochondrial activity, and reactive oxygen species generation which was significantly attenuated with piracetam co-treatment. Cells co-treated with LPS and piracetam exhibited significant uptake of piracetam in comparison to only piracetam-treated cells as estimated by liquid chromatography-mass spectrometry (LC-MSMS). LPS treatment caused significant translocation of AIF and endonuclease-G in neuronal N2A cells which were significantly attenuated with piracetam co-treatment. Significant over-expression of proinflammatory cytokines was also observed after treatment of LPS to cells which was inhibited with piracetam co-treatment demonstrating its anti-inflammatory property. LPS-treated cells exhibited significant oxidative DNA fragmentation and poly [ADP-ribose] polymerase-1 (PARP-1) up-regulation in nucleus, both of which were attenuated with piracetam treatment. Antioxidant melatonin but not z-VAD offered the inhibited LPS-induced DNA fragmentation indicating the involvement of oxidative DNA fragmentation. Further, we did not observe the altered caspase-3 level after LPS treatment initially while at a later time point, significantly augmented level of caspase-3 was observed which was not inhibited with piracetam treatment. In total, our findings indicate the interference of piracetam in mitochondrion-mediated caspase-independent pathway, as well as its anti-inflammatory and antioxidative properties. Graphical Abstract Graphical abstract indicating the novel interference of metabolic enhancer piracetam (P) in neuronal death mechanisms.
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Affiliation(s)
- Dinesh Kumar Verma
- Toxicology Division, CSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, 226031, India
| | - Sonam Gupta
- Toxicology Division, CSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, 226031, India
| | - Joyshree Biswas
- Toxicology Division, CSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, 226031, India
| | - Neeraj Joshi
- Department of Biochemistry and Biophysics, Helen Diller Comprehensive Cancer Center, University of California San Francisco, San Francisco, CA, USA
| | - K Sivarama Raju
- Pharmacokinetics & Metabolism Division, CSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, 226031, India
| | - Mu Wahajuddin
- Pharmacokinetics & Metabolism Division, CSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, 226031, India
| | - Sarika Singh
- Toxicology Division, CSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, 226031, India.
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Zhang K, Wang H, Xu M, Frank JA, Luo J. Role of MCP-1 and CCR2 in ethanol-induced neuroinflammation and neurodegeneration in the developing brain. J Neuroinflammation 2018; 15:197. [PMID: 29976212 PMCID: PMC6034273 DOI: 10.1186/s12974-018-1241-2] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 06/26/2018] [Indexed: 01/06/2023] Open
Abstract
Background Neuroinflammation and microglial activation have been implicated in both alcohol use disorders (AUD) and fetal alcohol spectrum disorders (FASD). Chemokine monocyte chemoattractant protein 1 (MCP-1) and its receptor C-C chemokine receptor type 2 (CCR2) are critical mediators of neuroinflammation and microglial activation. FASD is the leading cause of mental retardation, and one of the most devastating outcomes of FASD is the loss of neurons in the central nervous system (CNS). The underlying molecular mechanisms, however, remain unclear. We hypothesize that MCP-1/CCR2 signaling mediates ethanol-induced neuroinflammation and microglial activation, which exacerbates neurodegeneration in the developing brain. Methods C57BL/6 mice and mice deficient of MCP-1 (MCP-1−/−) and CCR2 (CCR2−/−) were exposed to ethanol on postnatal day 4 (PD4). Neuroinflammation, and microglial activation, and neurodegeneration in the brain were evaluated by immunohistochemistry and immunoblotting. A neuronal and microglial co-culture system was used to evaluate the role of microglia and MCP-1/CCR2 signaling in ethanol-induced neurodegeneration. Specific inhibitors were employed to delineate the involved signaling pathways. Results Ethanol-induced microglial activation, neuroinflammation, and a drastic increase in the mRNA and protein levels of MCP-1. Treatment of Bindarit (MCP-1 synthesis inhibitor) and RS504393 (CCR2 antagonist) significantly reduced ethanol-induced microglia activation/neuroinflammation, and neuroapoptosis in the developing brain. MCP-1−/− and CCR2−/− mice were more resistant to ethanol-induced neuroapoptosis. Moreover, ethanol plus MCP-1 caused more neuronal death in a neuron/microglia co-culture system than neuronal culture alone, and Bindarit and RS504393 attenuated ethanol-induced neuronal death in the co-culture system. Ethanol activated TLR4 and GSK3β, two key mediators of microglial activation in the brain and cultured microglial cells (SIM-A9). Blocking MCP-1/CCR2 signaling attenuated ethanol-induced activation of TLR4 and GSK3β. Conclusion MCP-1/CCR2 signaling played an important role in ethanol-induced microglial activation/neuroinflammation and neurodegeneration in the developing brain. The effects may be mediated by the interaction among MCP-1/CCR2 signaling, TLR4, and GSK3β.
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Affiliation(s)
- Kai Zhang
- Department of Pharmacology and Nutritional Sciences, University of Kentucky College of Medicine, 132 Health Sciences Research Building, 1095 Veterans Drive, Lexington, KY, 40536, USA
| | - Haiping Wang
- Department of Pharmacology and Nutritional Sciences, University of Kentucky College of Medicine, 132 Health Sciences Research Building, 1095 Veterans Drive, Lexington, KY, 40536, USA
| | - Mei Xu
- Department of Pharmacology and Nutritional Sciences, University of Kentucky College of Medicine, 132 Health Sciences Research Building, 1095 Veterans Drive, Lexington, KY, 40536, USA
| | - Jacqueline A Frank
- Department of Pharmacology and Nutritional Sciences, University of Kentucky College of Medicine, 132 Health Sciences Research Building, 1095 Veterans Drive, Lexington, KY, 40536, USA
| | - Jia Luo
- Department of Pharmacology and Nutritional Sciences, University of Kentucky College of Medicine, 132 Health Sciences Research Building, 1095 Veterans Drive, Lexington, KY, 40536, USA.
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Das S, Mishra K, Ganju L, Singh S. Intranasally delivered small interfering RNA-mediated suppression of scavenger receptor Mac-1 attenuates microglial phenotype switching and working memory impairment following hypoxia. Neuropharmacology 2018; 137:240-255. [DOI: 10.1016/j.neuropharm.2018.05.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 04/22/2018] [Accepted: 05/02/2018] [Indexed: 01/06/2023]
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Park J, Wetzel I, Marriott I, Dréau D, D'Avanzo C, Kim DY, Tanzi RE, Cho H. A 3D human triculture system modeling neurodegeneration and neuroinflammation in Alzheimer's disease. Nat Neurosci 2018; 21:941-951. [PMID: 29950669 PMCID: PMC6800152 DOI: 10.1038/s41593-018-0175-4] [Citation(s) in RCA: 391] [Impact Index Per Article: 65.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 05/25/2018] [Indexed: 01/26/2023]
Abstract
Alzheimer's disease (AD) is characterized by beta-amyloid accumulation, phosphorylated tau formation, hyperactivation of glial cells, and neuronal loss. The mechanisms of AD pathogenesis, however, remain poorly understood, partially due to the lack of relevant models that can comprehensively recapitulate multistage intercellular interactions in human AD brains. Here we present a new three-dimensional (3D) human AD triculture model using neurons, astrocytes, and microglia in a 3D microfluidic platform. Our model provided key representative AD features: beta-amyloid aggregation, phosphorylated tau accumulation, and neuroinflammatory activity. In particular, the model mirrored microglial recruitment, neurotoxic activities such as axonal cleavage, and NO release damaging AD neurons and astrocytes. Our model will serve to facilitate the development of more precise human brain models for basic mechanistic studies in neural-glial interactions and drug discovery.
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Affiliation(s)
- Joseph Park
- Department of Mechanical Engineering and Engineering Science, University of North Carolina at Charlotte, Charlotte, NC, USA.,Center for Biomedical Engineering and Science, University of North Carolina at Charlotte, Charlotte, NC, USA.,Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC, USA.,The Nanoscale Science Program, University of North Carolina at Charlotte, Charlotte, NC, USA.,Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Isaac Wetzel
- Department of Mechanical Engineering and Engineering Science, University of North Carolina at Charlotte, Charlotte, NC, USA.,Center for Biomedical Engineering and Science, University of North Carolina at Charlotte, Charlotte, NC, USA.,Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC, USA.,The Nanoscale Science Program, University of North Carolina at Charlotte, Charlotte, NC, USA
| | - Ian Marriott
- Center for Biomedical Engineering and Science, University of North Carolina at Charlotte, Charlotte, NC, USA.,Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC, USA
| | - Didier Dréau
- Center for Biomedical Engineering and Science, University of North Carolina at Charlotte, Charlotte, NC, USA.,Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC, USA
| | - Carla D'Avanzo
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Doo Yeon Kim
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Rudolph E Tanzi
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Hansang Cho
- Department of Mechanical Engineering and Engineering Science, University of North Carolina at Charlotte, Charlotte, NC, USA. .,Center for Biomedical Engineering and Science, University of North Carolina at Charlotte, Charlotte, NC, USA. .,Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC, USA. .,The Nanoscale Science Program, University of North Carolina at Charlotte, Charlotte, NC, USA.
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Durrant A, Swift M, Beazley-Long N. A role for pericytes in chronic pain? Curr Opin Support Palliat Care 2018; 12:154-161. [PMID: 29553988 PMCID: PMC6027993 DOI: 10.1097/spc.0000000000000342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
PURPOSE OF REVIEW The importance of the blood-brain barrier (BBB) and neuroinflammation in neurodegenerative conditions is becoming increasingly apparent, yet very little is known about these neurovascular functions in nonmalignant disease chronic pain. Neural tissue pericytes play critical roles in the formation and maintenance of the BBB. Herein, we review the important roles of neural pericytes and address their potential role in chronic pain. RECENT FINDINGS Pericytes are implicated in the function of neural microvasculature, including BBB permeability, neuroimmune factor secretion and leukocyte transmigration. In addition, the multipotent stem cell nature of pericytes affords pericytes the ability to migrate into neural parenchyma and differentiate into pain-associated cell types. These recent findings indicate that pericytes are key players in pathological BBB disruption and neuroinflammation, and as such pericytes may be key players in chronic pain states. SUMMARY Pericytes play key roles in pathological processes associated with chronic pain. We propose that pericytes may be a therapeutic target for painful diseases that have associated neural vascular dysfunction. Given the paucity of new pharmacotherapies for chronic pain conditions, we hope that this review inspires researchers to unearth the potential role(s) of pericytes in chronic pain sowing the seeds for future new chronic pain therapies.
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Affiliation(s)
- A.M. Durrant
- Arthritis Research UK Pain Centre & School of Life Sciences, Medical School, University of Nottingham, Nottingham NG7 2UH
| | - M.N Swift
- Arthritis Research UK Pain Centre & School of Life Sciences, Medical School, University of Nottingham, Nottingham NG7 2UH
| | - N. Beazley-Long
- Arthritis Research UK Pain Centre & School of Life Sciences, Medical School, University of Nottingham, Nottingham NG7 2UH
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119
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Vodovozov W, Schneider J, Elzoheiry S, Hollnagel JO, Lewen A, Kann O. Metabolic modulation of neuronal gamma-band oscillations. Pflugers Arch 2018; 470:1377-1389. [DOI: 10.1007/s00424-018-2156-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 04/06/2018] [Accepted: 05/17/2018] [Indexed: 01/08/2023]
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Abstract
Microglia are a subset of tissue macrophages that constitute the major immune cell type of the central nervous system. These cells have long been known to change their morphology and functions in response to various neurological insults. Recently, a plethora of unbiased transcriptomics studies have revealed that across a broad spectrum of neurodegeneration-like disease models, microglia adopt a similar activation signature and perform similar functions. Despite these commonalities in response, the role of microglia has been described as both positive and negative in different murine disease models. In humans, genetic association studies have revealed strong connections between microglia genes and various neurodegenerative diseases, and mechanistic investigations of these mutations have added another layer of complexity. Here, we provide an overview of studies that have built a case for a common microglial response to neurodegeneration and discuss pathways that may be important to initiate and sustain this response; delineate the multifaceted functions of activated microglia spanning different diseases; and discuss insights from studying genes associated with disease in humans. We argue that strong evidence causally links activated microglia function to neurodegeneration and discuss what seems to be a conflict between mouse models and human genetics.
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Affiliation(s)
- Wilbur M Song
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, United States
| | - Marco Colonna
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, United States.
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Zeng Q, Hu C, Qi R, Lu D. PYNOD reduces microglial inflammation and consequent neurotoxicity upon lipopolysaccharides stimulation. Exp Ther Med 2018; 15:5337-5343. [PMID: 29904414 PMCID: PMC5996706 DOI: 10.3892/etm.2018.6108] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Accepted: 03/28/2018] [Indexed: 01/01/2023] Open
Abstract
PYNOD, a nod-like receptors (NLR)-like protein, was indicated to inhibit NF-κB activation, caspase-1-mediated interleukin (IL)-1β release and cell apoptosis in a dose-dependent manner. Exogenous addition of recombinant PYNOD to mixed glial cultures may suppress caspase-1 activation and IL-1β secretion induced by Aβ. However, to the best of our knowledge, there no study has focused on the immunoregulatory effects of PYNOD specifically in microglia. The present study aimed to explore the roles of PYNOD involved in the lipopolysaccharides (LPS)-induced microglial inflammation and consequent neurotoxicity. Murine microglial BV-2 cells were transfected with pEGFP-C2-PYNOD (0–5.0 µg/ml) for 24 h and incubated with or without LPS (1 µg/ml) for a further 24 h. Cell viability was determined using MTT assay and the secretion of nitric oxide (NO), IL-1β and caspase-1 was measured using the Griess method or ELISA. Protein expression levels of NF-κB p65 and inducible nitric oxide synthase (iNOS) were detected by immunofluorescent staining and/or western blot analysis. Co-culture of BV-2 cells with human neuroblastoma cell line SK-N-SH was performed in Transwell plates and the cell viability and apoptosis (using flow cytometry) of SK-N-SH cells were determined. Results indicated that PYNOD overexpression inhibited NO secretion and iNOS protein expression induced by LPS in BV-2 cells, with no detectable cytotoxicity. PYNOD overexpression also reduced the secretion of IL-1β and caspase-1 from BV-2 cells upon LPS stimulation. These effects were dose-dependent. Additionally, PYNOD overexpression prevented LPS-induced nuclear translocation of NF-κB p65 in BV-2 cells. The growth-inhibitory and apoptosis-promoting effects of BV-2 cells towards SK-N-SH cells were alleviated as a result of PYNOD overexpression. In conclusion, PYNOD may mitigate microglial inflammation and consequent neurotoxicity.
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Affiliation(s)
- Qi Zeng
- Department of Ultrasonic Diagnosis, The First Affiliated Hospital of Gannan Medical College, Ganzhou, Jiangxi 341000, P.R. China
| | - Chaofeng Hu
- Key Laboratory of State Administration of Traditional Chinese Medicine of The People's Republic of China, Institute of Brain Research, Department of Pathophysiology, School of Medicine, Jinan University, Guangzhou, Guangdong 510632, P.R. China
| | - Renbin Qi
- Key Laboratory of State Administration of Traditional Chinese Medicine of The People's Republic of China, Institute of Brain Research, Department of Pathophysiology, School of Medicine, Jinan University, Guangzhou, Guangdong 510632, P.R. China
| | - Daxiang Lu
- Key Laboratory of State Administration of Traditional Chinese Medicine of The People's Republic of China, Institute of Brain Research, Department of Pathophysiology, School of Medicine, Jinan University, Guangzhou, Guangdong 510632, P.R. China
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Kiguchi N, Kobayashi D, Saika F, Matsuzaki S, Kishioka S. Inhibition of peripheral macrophages by nicotinic acetylcholine receptor agonists suppresses spinal microglial activation and neuropathic pain in mice with peripheral nerve injury. J Neuroinflammation 2018; 15:96. [PMID: 29587798 PMCID: PMC5872578 DOI: 10.1186/s12974-018-1133-5] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Accepted: 03/15/2018] [Indexed: 12/24/2022] Open
Abstract
Background Neuro–immune interaction underlies chronic neuroinflammation and aberrant sensory processing resulting in neuropathic pain. Despite the pathological significance of both neuroinflammation-driven peripheral sensitization and spinal sensitization, the functional relationship between these two distinct events has not been understood. Methods In this study, we determined whether inhibition of inflammatory macrophages by administration of α4β2 nicotinic acetylcholine receptor (nAChR) agonists improves neuropathic pain and affects microglial activation in the spinal dorsal horn (SDH) in mice following partial sciatic nerve ligation (PSL). Expression levels of neuroinflammatory molecules were evaluated by RT-qPCR and immunohistochemistry, and PSL-induced mechanical allodynia was defined by the von Frey test. Results Flow cytometry revealed that CD11b+ F4/80+ macrophages were accumulated in the injured sciatic nerve (SCN) after PSL. TC-2559, a full agonist for α4β2 nAChR, suppressed the upregulation of interleukin-1β (IL-1β) in the injured SCN after PSL and attenuated lipopolysaccharide-induced upregulation of IL-1β in cultured macrophages. Systemic (subcutaneous, s.c.) administration of TC-2559 during either the early (days 0–3) or middle/late (days 7–10) phase of PSL improved mechanical allodynia. Moreover, local (perineural, p.n.) administration of TC-2559 and sazetidine A, a partial agonist for α4β2 nAChR, during either the early or middle phase of PSL improved mechanical allodynia. However, p.n. administration of sazetidine A during the late (days 21–24) phase did not show the attenuating effect, whereas p.n. administration of TC-2559 during this phase relieved mechanical allodynia. Most importantly, p.n. administration of TC-2559 significantly suppressed morphological activation of Iba1+ microglia and decreased the upregulation of inflammatory microglia-dominant molecules, such as CD68, interferon regulatory factor 5, and IL-1β in the SDH after PSL. Conclusion These findings support the notion that pharmacological inhibition of inflammatory macrophages using an α4β2 nAChR agonist exhibit a wide therapeutic window on neuropathic pain after nerve injury, and it could be nominated as a novel pharmacotherapy to relieve intractable pain. Electronic supplementary material The online version of this article (10.1186/s12974-018-1133-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Norikazu Kiguchi
- Department of Pharmacology, Wakayama Medical University, 811-1 Kimiidera, Wakayama city, Wakayama, 641-0012, Japan.
| | - Daichi Kobayashi
- Department of Pharmacology, Wakayama Medical University, 811-1 Kimiidera, Wakayama city, Wakayama, 641-0012, Japan
| | - Fumihiro Saika
- Department of Pharmacology, Wakayama Medical University, 811-1 Kimiidera, Wakayama city, Wakayama, 641-0012, Japan
| | - Shinsuke Matsuzaki
- Department of Pharmacology, Wakayama Medical University, 811-1 Kimiidera, Wakayama city, Wakayama, 641-0012, Japan
| | - Shiroh Kishioka
- Department of Pharmacology, Wakayama Medical University, 811-1 Kimiidera, Wakayama city, Wakayama, 641-0012, Japan
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Beazley-Long N, Durrant AM, Swift MN, Donaldson LF. The physiological functions of central nervous system pericytes and a potential role in pain. F1000Res 2018; 7:341. [PMID: 29623199 PMCID: PMC5861511 DOI: 10.12688/f1000research.13548.1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/16/2018] [Indexed: 12/29/2022] Open
Abstract
Central nervous system (CNS) pericytes regulate critical functions of the neurovascular unit in health and disease. CNS pericytes are an attractive pharmacological target for their position within the neurovasculature and for their role in neuroinflammation. Whether the function of CNS pericytes also affects pain states and nociceptive mechanisms is currently not understood. Could it be that pericytes hold the key to pain associated with CNS blood vessel dysfunction? This article reviews recent findings on the important physiological functions of CNS pericytes and highlights how these neurovascular functions could be linked to pain states.
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Affiliation(s)
- Nicholas Beazley-Long
- Arthritis Research UK Pain Centre & School of Life Sciences, Medical School, University of Nottingham, Nottingham, UK
| | - Alexandra M Durrant
- Arthritis Research UK Pain Centre & School of Life Sciences, Medical School, University of Nottingham, Nottingham, UK
| | - Matthew N Swift
- Arthritis Research UK Pain Centre & School of Life Sciences, Medical School, University of Nottingham, Nottingham, UK
| | - Lucy F Donaldson
- Arthritis Research UK Pain Centre & School of Life Sciences, Medical School, University of Nottingham, Nottingham, UK
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Bonaterra GA, Schwendler A, Hüther J, Schwarzbach H, Schwarz A, Kolb C, Abdel-Aziz H, Kinscherf R. Neurotrophic, Cytoprotective, and Anti-inflammatory Effects of St. John's Wort Extract on Differentiated Mouse Hippocampal HT-22 Neurons. Front Pharmacol 2018; 8:955. [PMID: 29403374 PMCID: PMC5778116 DOI: 10.3389/fphar.2017.00955] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 12/15/2017] [Indexed: 12/30/2022] Open
Abstract
Introduction: Since ancient times Hypericum perforatum L. named St. John's wort (SJW), has been used in the management of a wide range of applications, including nervous disorders. Development of mood disorders are due to alterations in glutamate metabolism, initiation of inflammatory pathways, and changes of the neuronal plasticity. Previous studies suggest that the glutamatergic system contributes to the pathophysiology of depression. Extracts of SJW have been recommended for the treatment of depression. The aim of the present in vitro study was to evaluate the action of STW3-VI, a special SJW extract in differentiated mouse hippocampal HT-22 neurons. We evaluated the stimulation of neurogenesis, the protective effect against glutamate or N-methyl-D-aspartate receptor induced-excitotoxicity and its anti-inflammatory properties in LPS-activated human macrophages. Results: After 48 h treatment, STW3-VI stimulated the neurite formation by 25% in comparison with the control and showed protective effects against glutamate- or NMDA-induced cytotoxicity by significantly increasing the viability about +25 or +50%. In conjunction with these effects, after pretreatment with STW3-VI, the intracellular reduced glutathione content was significantly 2.3-fold increased compared with the neurons incubated with glutamate alone. Additionally, pre-treatment of human macrophages with STW3-VI showed anti-inflammatory effects after 24 or 48 h concerning inhibition of LPS-induced TNF release by -47.3 and -53.8% (24 h) or -25.0 to -64.8% (48 h). Conclusions: Our data provide new evidence that STW3-VI protects hippocampal cells from NMDA- or glutamate-induced cytotoxicity. Moreover, our results indicate a morphological remodeling by increasing neurite outgrowth and activation of the anti-inflammatory defense by inhibition of the cytokine production in human macrophages after STW3-VI treatment. These protective, neurotrophic and anti-inflammatory properties may be beneficial in the treatment of depressive disorders.
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Affiliation(s)
- Gabriel A Bonaterra
- Department of Medical Cell Biology, Institute for Anatomy and Cell Biology, Philipps-University of Marburg, Marburg, Germany
| | - Anna Schwendler
- Department of Medical Cell Biology, Institute for Anatomy and Cell Biology, Philipps-University of Marburg, Marburg, Germany
| | - Julian Hüther
- Department of Medical Cell Biology, Institute for Anatomy and Cell Biology, Philipps-University of Marburg, Marburg, Germany
| | - Hans Schwarzbach
- Department of Medical Cell Biology, Institute for Anatomy and Cell Biology, Philipps-University of Marburg, Marburg, Germany
| | - Anja Schwarz
- Department of Medical Cell Biology, Institute for Anatomy and Cell Biology, Philipps-University of Marburg, Marburg, Germany
| | - Christiane Kolb
- Steigerwald Arzneimittelwerk GmbH, Scientific Department, Darmstadt, Germany
| | - Heba Abdel-Aziz
- Steigerwald Arzneimittelwerk GmbH, Scientific Department, Darmstadt, Germany
| | - Ralf Kinscherf
- Department of Medical Cell Biology, Institute for Anatomy and Cell Biology, Philipps-University of Marburg, Marburg, Germany
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125
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Saliba SW, Marcotegui AR, Fortwängler E, Ditrich J, Perazzo JC, Muñoz E, de Oliveira ACP, Fiebich BL. AM404, paracetamol metabolite, prevents prostaglandin synthesis in activated microglia by inhibiting COX activity. J Neuroinflammation 2017; 14:246. [PMID: 29237478 PMCID: PMC5729401 DOI: 10.1186/s12974-017-1014-3] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Accepted: 11/27/2017] [Indexed: 01/09/2023] Open
Abstract
Background N-arachidonoylphenolamine (AM404), a paracetamol metabolite, is a potent agonist of the transient receptor potential vanilloid type 1 (TRPV1) and low-affinity ligand of the cannabinoid receptor type 1 (CB1). There is evidence that AM404 exerts its pharmacological effects in immune cells. However, the effect of AM404 on the production of inflammatory mediators of the arachidonic acid pathway in activated microglia is still not fully elucidated. Method In the present study, we investigated the effects of AM404 on the eicosanoid production induced by lipopolysaccharide (LPS) in organotypic hippocampal slices culture (OHSC) and primary microglia cultures using Western blot, immunohistochemistry, and ELISA. Results Our results show that AM404 inhibited LPS-mediated prostaglandin E2 (PGE2) production in OHSC, and LPS-stimulated PGE2 release was totally abolished in OHSC if microglial cells were removed. In primary microglia cultures, AM404 led to a significant dose-dependent decrease in the release of PGE2, independent of TRPV1 or CB1 receptors. Moreover, AM404 also inhibited the production of PGD2 and the formation of reactive oxygen species (8-iso-PGF2 alpha) with a reversible reduction of COX-1- and COX-2 activity. Also, it slightly decreased the levels of LPS-induced COX-2 protein, although no effect was observed on LPS-induced mPGES-1 protein synthesis. Conclusions This study provides new significant insights about the potential anti-inflammatory role of AM404 and new mechanisms of action of paracetamol on the modulation of prostaglandin production by activated microglia. Electronic supplementary material The online version of this article (10.1186/s12974-017-1014-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Soraya Wilke Saliba
- Department of Psychiatry and Psychotherapy, Laboratory of Translational Psychiatry, Faculty of Medicine, Medical Center - University of Freiburg, Hauptstr. 5, 79104, Freiburg, Germany. .,Faculty of Biology, University of Freiburg, Freiburg, Germany.
| | - Ariel R Marcotegui
- Laboratory of Hepatic Encephalopathy and Portal Hypertension, Center of Applied and Experimental Pathology, University of Buenos Aires, Buenos Aires, Argentina
| | - Ellen Fortwängler
- Department of Psychiatry and Psychotherapy, Laboratory of Translational Psychiatry, Faculty of Medicine, Medical Center - University of Freiburg, Hauptstr. 5, 79104, Freiburg, Germany
| | - Johannes Ditrich
- Department of Psychiatry and Psychotherapy, Laboratory of Translational Psychiatry, Faculty of Medicine, Medical Center - University of Freiburg, Hauptstr. 5, 79104, Freiburg, Germany
| | - Juan Carlos Perazzo
- Laboratory of Hepatic Encephalopathy and Portal Hypertension, Center of Applied and Experimental Pathology, University of Buenos Aires, Buenos Aires, Argentina
| | - Eduardo Muñoz
- Departamento de Biología Celular, Instituto Maimónides de Investigación Biomédica de Córdoba, Hospital Universitario Reina Sofía, Fisiología e Inmunología, Universidad de Córdoba, Córdoba, Spain
| | | | - Bernd L Fiebich
- Department of Psychiatry and Psychotherapy, Laboratory of Translational Psychiatry, Faculty of Medicine, Medical Center - University of Freiburg, Hauptstr. 5, 79104, Freiburg, Germany.
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126
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Spatio-temporal expression of Hexokinase-3 in the injured female rat spinal cords. Neurochem Int 2017; 113:23-33. [PMID: 29196144 DOI: 10.1016/j.neuint.2017.11.015] [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: 09/07/2017] [Revised: 11/22/2017] [Accepted: 11/27/2017] [Indexed: 11/20/2022]
Abstract
Hexokinase-3 (HK3) is a member of hexokinase family, which can catalyze the first step of glucose metabolism. It can increase ATP levels, reduce the production of reactive oxygen species, increase mitochondrial biogenesis, protect mitochondrial membrane potential and play an antioxidant role. However, the change of its expression in spinal cord after injury is still unknown. In this study, we investigated the spatio-temporal expression of HK3 in the spinal cords by using a spinal cord injury (SCI) model in adult female Sprague-Dawley rats. Quantitative reverse transcription-PCR and western blot analysis revealed that HK3 could be detected in sham-opened spinal cords. After SCI, it gradually increased, reached a peak at 7 days post-injury (dpi), and then gradually decreased with the prolonging of injury time, but still maintained at a higher level for up to 28 dpi (the longest time evaluated in this study). Immunofluorescence staining showed that HK3 was found in GFAP+, β-tubulin III+ and IBA-1+ cells in sham-opened spinal cords. After SCI, in addition to the above-mentioned cells, it could also be found in CD45+ and CD68+ cells. These results demonstrate that HK3 is mainly expressed in astrocytes, neurons and microglia in normal spinal cords, and could rapidly increase in infiltrated leukocytes, activated microglia/macrophages and astrocytes after SCI. These data suggest that HK3 may be involved in the pathologic process of SCI by promoting glucose metabolism.
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127
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Ghafelehbashi H, Pahlevan Kakhki M, Kular L, Moghbelinejad S, Ghafelehbashi SH. Decreased Expression of IFNG-AS1
,IFNG
and IL-1B
Inflammatory Genes in Medicated Schizophrenia and Bipolar Patients. Scand J Immunol 2017; 86:479-485. [DOI: 10.1111/sji.12620] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 10/09/2017] [Indexed: 01/22/2023]
Affiliation(s)
- H. Ghafelehbashi
- Cellular and Molecular Research Center; Qazvin University of Medical Sciences; Qazvin Iran
| | - M. Pahlevan Kakhki
- Department of Genetics; Faculty of Biological Sciences; Tarbiat Modares University; Tehran Iran
| | - L. Kular
- Department of Clinical Neuroscience; Center for Molecular Medicine; Karolinska Institute; Karolinska University Hospital; Stockholm Sweden
| | - S. Moghbelinejad
- Cellular and Molecular Research Center; Qazvin University of Medical Sciences; Qazvin Iran
- Department of Psychiatry; Qazvin University of Medical Sciences; Qazvin Iran
| | - S. H. Ghafelehbashi
- Cellular and Molecular Research Center; Qazvin University of Medical Sciences; Qazvin Iran
- Department of Psychiatry; Qazvin University of Medical Sciences; Qazvin Iran
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128
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Gamma Interferon Mediates Experimental Cerebral Malaria by Signaling within Both the Hematopoietic and Nonhematopoietic Compartments. Infect Immun 2017; 85:IAI.01035-16. [PMID: 28874445 PMCID: PMC5649021 DOI: 10.1128/iai.01035-16] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2016] [Accepted: 08/23/2017] [Indexed: 12/18/2022] Open
Abstract
Experimental cerebral malaria (ECM) is a gamma interferon (IFN-γ)-dependent syndrome. However, whether IFN-γ promotes ECM through direct and synergistic targeting of multiple cell populations or by acting primarily on a specific responsive cell type is currently unknown. Here, using a panel of cell- and compartment-specific IFN-γ receptor 2 (IFN-γR2)-deficient mice, we show that IFN-γ causes ECM by signaling within both the hematopoietic and nonhematopoietic compartments. Mechanistically, hematopoietic and nonhematopoietic compartment-specific IFN-γR signaling exerts additive effects in orchestrating intracerebral inflammation, leading to the development of ECM. Surprisingly, mice with specific deletion of IFN-γR2 expression on myeloid cells, T cells, or neurons were completely susceptible to terminal ECM. Utilizing a reductionist in vitro system, we show that synergistic IFN-γ and tumor necrosis factor (TNF) stimulation promotes strong activation of brain blood vessel endothelial cells. Combined, our data show that within the hematopoietic compartment, IFN-γ causes ECM by acting redundantly or by targeting non-T cell or non-myeloid cell populations. Within the nonhematopoietic compartment, brain endothelial cells, but not neurons, may be the major target of IFN-γ leading to ECM development. Collectively, our data provide information on how IFN-γ mediates the development of cerebral pathology during malaria infection.
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129
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Woo J, Han D, Wang JI, Park J, Kim H, Kim Y. Quantitative Proteomics Reveals Temporal Proteomic Changes in Signaling Pathways during BV2 Mouse Microglial Cell Activation. J Proteome Res 2017; 16:3419-3432. [DOI: 10.1021/acs.jproteome.7b00445] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
| | - Dohyun Han
- Proteomics
Core Facility, Biomedical Research Institute, Seoul National University Hospital, 101 Daehangro, Seoul 110-799, Korea
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130
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Ginkgolide B Suppresses Methamphetamine-Induced Microglial Activation Through TLR4-NF-κB Signaling Pathway in BV2 Cells. Neurochem Res 2017; 42:2881-2891. [DOI: 10.1007/s11064-017-2309-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Revised: 02/14/2017] [Accepted: 05/22/2017] [Indexed: 01/20/2023]
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131
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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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132
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Hoeijmakers L, Ruigrok SR, Amelianchik A, Ivan D, van Dam AM, Lucassen PJ, Korosi A. Early-life stress lastingly alters the neuroinflammatory response to amyloid pathology in an Alzheimer's disease mouse model. Brain Behav Immun 2017; 63:160-175. [PMID: 28027926 DOI: 10.1016/j.bbi.2016.12.023] [Citation(s) in RCA: 92] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 12/12/2016] [Accepted: 12/23/2016] [Indexed: 12/16/2022] Open
Abstract
Exposure to stress during the sensitive period of early-life increases the risk to develop cognitive impairments and psychopathology later in life. In addition, early-life stress (ES) exposure, next to genetic causes, has been proposed to modulate the development and progression of Alzheimer's disease (AD), however evidence for this hypothesis is currently lacking. We here tested whether ES modulates progression of AD-related neuropathology and assessed the possible contribution of neuroinflammatory factors in this. We subjected wild-type (WT) and transgenic APP/PS1 mice, as a model for amyloid neuropathology, to chronic ES from postnatal day (P)2 to P9. We next studied how ES exposure affected; 1) amyloid β (Aβ) pathology at an early (4month old) and at a more advanced pathological (10month old) stage, 2) neuroinflammatory mediators immediately after ES exposure as well as in adult WT mice, and 3) the neuroinflammatory response in relation to Aβ neuropathology. ES exposure resulted in a reduction of cell-associated amyloid in 4month old APP/PS1 mice, but in an exacerbation of Aβ plaque load at 10months of age, demonstrating that ES affects Aβ load in the hippocampus in an age-dependent manner. Interestingly, ES modulated various neuroinflammatory mediators in the hippocampus of WT mice as well as in response to Aβ neuropathology. In WT mice, immediately following ES exposure (P9), Iba1-immunopositive microglia exhibited reduced complexity and hippocampal interleukin (IL)-1β expression was increased. In contrast, microglial Iba1 and CD68 were increased and hippocampal IL-6 expression was decreased at 4months, while these changes resolved by 10months of age. Finally, Aβ neuropathology triggered a neuroinflammatory response in APP/PS1 mice that was altered after ES exposure. APP/PS1 mice exhibited increased CD68 expression at 4months, which was further enhanced by ES, whereas the microglial response to Aβ neuropathology, as measured by Iba1 and CD11b, was less prominent after ES at 10months of age. Finally, the hippocampus appears to be more vulnerable for these ES-induced effects, since ES did not affect Aβ neuropathology and neuroinflammation in the entorhinal cortex of adult ES exposed mice. Overall, our results demonstrate that ES exposure has both immediate and lasting effects on the neuroinflammatory response. In the context of AD, such alterations in neuroinflammation might contribute to aggravated neuropathology in ES exposed mice, hence altering disease progression. This indicates that, at least in a genetic context, ES could aggravate AD pathology.
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Affiliation(s)
- Lianne Hoeijmakers
- Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, Science Park 904, Amsterdam, The Netherlands
| | - Silvie R Ruigrok
- Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, Science Park 904, Amsterdam, The Netherlands
| | - Anna Amelianchik
- Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, Science Park 904, Amsterdam, The Netherlands
| | - Daniela Ivan
- Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, Science Park 904, Amsterdam, The Netherlands
| | - Anne-Marie van Dam
- Department of Anatomy & Neurosciences, Amsterdam Neuroscience, VU University Medical Center, De Boelelaan 1108, Amsterdam, The Netherlands
| | - Paul J Lucassen
- Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, Science Park 904, Amsterdam, The Netherlands
| | - Aniko Korosi
- Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, Science Park 904, Amsterdam, The Netherlands.
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133
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Cocaine-Mediated Downregulation of miR-124 Activates Microglia by Targeting KLF4 and TLR4 Signaling. Mol Neurobiol 2017; 55:3196-3210. [PMID: 28478506 DOI: 10.1007/s12035-017-0584-5] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 04/27/2017] [Indexed: 12/26/2022]
Abstract
Cocaine is known to activate microglia both in vitro and in vivo. High expression of microglial Toll-like receptors (TLRs) and their downstream signal transducers play critical roles in determining microglial activation status. Emerging reports have also demonstrated that cocaine can enhance the strength of TLR signaling. Detailed molecular mechanisms underlying this phenomenon, however, remain elusive. In this study, we investigated the role(s) of miR-124 in regulating microglial TLR4 signaling in the context of cocaine. Herein, we found a dose- and time-dependent upregulation of KLF4 in cocaine-exposed BV-2 cells and rat primary microglial cells (rPMs). KLF4 also identified as a novel 3'-UTR target directly regulated by miR-124. In parallel, miR-124 regulated multiple TLR4 signaling molecules including TLR4, MyD88, TRAF6, and IRAK1. Repeated doses of cocaine (20 mg/kg; i.p.) administration in mice for 7 days further validated the in vitro key findings. Also, miR-124 overexpression significantly blocked the cocaine-mediated upregulation of pro-inflammatory cytokines. In contrast, miR-124 overexpression notably increased the expression of anti-inflammatory mediators in cocaine-exposed microglial cells. Intriguingly, stereotactic administration of lentivirus-miR-124 in the striatum significantly inhibited cocaine-mediated microglial activation and locomotor hyperactivity in vivo. In summary, these findings implicate the role of miR-124 in regulating TLR4 signaling, thereby indicating a new pathway responsible for cocaine-mediated microglial activation.
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134
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Au NPB, Ma CHE. Recent Advances in the Study of Bipolar/Rod-Shaped Microglia and their Roles in Neurodegeneration. Front Aging Neurosci 2017; 9:128. [PMID: 28522972 PMCID: PMC5415568 DOI: 10.3389/fnagi.2017.00128] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Accepted: 04/18/2017] [Indexed: 01/06/2023] Open
Abstract
Microglia are the resident immune cells of the central nervous system (CNS) and they contribute to primary inflammatory responses following CNS injuries. The morphology of microglia is closely associated with their functional activities. Most previous research efforts have attempted to delineate the role of ramified and amoeboid microglia in the pathogenesis of neurodegenerative diseases. In addition to ramified and amoeboid microglia, bipolar/rod-shaped microglia were first described by Franz Nissl in 1899 and their presence in the brain was closely associated with the pathology of infectious diseases and sleeping disorders. However, studies relating to bipolar/rod-shaped microglia are very limited, largely due to the lack of appropriate in vitro and in vivo experimental models. Recent studies have reported the formation of bipolar/rod-shaped microglia trains in in vivo models of CNS injury, including diffuse brain injury, focal transient ischemia, optic nerve transection and laser-induced ocular hypertension (OHT). These bipolar/rod-shaped microglia formed end-to-end alignments in close proximity to the adjacent injured axons, but they showed no interactions with blood vessels or other types of glial cell. Recent studies have also reported on a highly reproducible in vitro culture model system to enrich bipolar/rod-shaped microglia that acts as a powerful tool with which to characterize this form of microglia. The molecular aspects of bipolar/rod-shaped microglia are of great interest in the field of CNS repair. This review article focuses on studies relating to the morphology and transformation of microglia into the bipolar/rod-shaped form, along with the differential gene expression and spatial distribution of bipolar/rod-shaped microglia in normal and pathological CNSs. The spatial arrangement of bipolar/rod-shaped microglia is crucial in the reorganization and remodeling of neuronal and synaptic circuitry following CNS injuries. Finally, we discuss the potential neuroprotective roles of bipolar/rod-shaped microglia, and the possibility of transforming ramified/amoeboid microglia into bipolar/rod-shaped microglia. This will be of considerable clinical benefit in the development of novel therapeutic strategies for treating various neurodegenerative diseases and promoting CNS repair after injury.
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Affiliation(s)
- Ngan Pan Bennett Au
- Department of Biomedical Sciences, City University of Hong KongKowloon Tong, Hong Kong
| | - Chi Him Eddie Ma
- Department of Biomedical Sciences, City University of Hong KongKowloon Tong, Hong Kong.,Centre for Biosystems, Neuroscience, and Nanotechnology, City University of Hong KongKowloon Tong, Hong Kong.,State Key Laboratory in Marine Pollution, City University of Hong KongKowloon Tong, Hong Kong
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135
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Klein RS, Garber C, Howard N. Infectious immunity in the central nervous system and brain function. Nat Immunol 2017; 18:132-141. [PMID: 28092376 DOI: 10.1038/ni.3656] [Citation(s) in RCA: 141] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Accepted: 12/02/2016] [Indexed: 11/09/2022]
Abstract
Inflammation is emerging as a critical mechanism underlying neurological disorders of various etiologies, yet its role in altering brain function as a consequence of neuroinfectious disease remains unclear. Although acute alterations in mental status due to inflammation are a hallmark of central nervous system (CNS) infections with neurotropic pathogens, post-infectious neurologic dysfunction has traditionally been attributed to irreversible damage caused by the pathogens themselves. More recently, studies indicate that pathogen eradication within the CNS may require immune responses that interfere with neural cell function and communication without affecting their survival. In this Review we explore inflammatory processes underlying neurological impairments caused by CNS infection and discuss their potential links to established mechanisms of psychiatric and neurodegenerative diseases.
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Affiliation(s)
- Robyn S Klein
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA.,Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, USA.,Department of Neuroscience, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Charise Garber
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Nicole Howard
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA.,Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA
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136
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Peña-Ortega F. Pharmacological Tools to Activate Microglia and their Possible use to Study Neural Network Patho-physiology. Curr Neuropharmacol 2017; 15:595-619. [PMID: 27697040 PMCID: PMC5543677 DOI: 10.2174/1570159x14666160928151546] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 08/05/2016] [Accepted: 09/26/2016] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Microglia are the resident immunocompetent cells of the CNS and also constitute a unique cell type that contributes to neural network homeostasis and function. Understanding microglia cell-signaling not only will reveal their diverse functions but also will help to identify pharmacological and non-pharmacological tools to modulate the activity of these cells. METHODS We undertook a search of bibliographic databases for peer-reviewed research literature to identify microglial activators and their cell-specificity. We also looked for their effects on neural network function and dysfunction. RESULTS We identified several pharmacological targets to modulate microglial function, which are more or less specific (with the proper control experiments). We also identified pharmacological targets that would require the development of new potent and specific modulators. We identified a wealth of evidence about the participation of microglia in neural network function and their alterations in pathological conditions. CONCLUSION The identification of specific microglia-activating signals provides experimental tools to modulate the activity of this heterogeneous cell type in order to evaluate its impact on other components of the nervous system, and it also helps to identify therapeutic approaches to ease some pathological conditions related to microglial dysfunction.
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Affiliation(s)
- Fernando Peña-Ortega
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, UNAM-Campus Juriquilla, México
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CD68/macrosialin: not just a histochemical marker. J Transl Med 2017; 97:4-13. [PMID: 27869795 DOI: 10.1038/labinvest.2016.116] [Citation(s) in RCA: 384] [Impact Index Per Article: 54.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 09/27/2016] [Accepted: 10/11/2016] [Indexed: 12/15/2022] Open
Abstract
CD68 is a heavily glycosylated glycoprotein that is highly expressed in macrophages and other mononuclear phagocytes. Traditionally, CD68 is exploited as a valuable cytochemical marker to immunostain monocyte/macrophages in the histochemical analysis of inflamed tissues, tumor tissues, and other immunohistopathological applications. CD68 alone or in combination with other cell markers of tumor-associated macrophages showed a good predictive value as a prognostic marker of survival in cancer patients. Lowression of CD68 was found in the lymphoid cells, non-hematopoietic cells (fibroblasts, endothelial cells, etc), and tumor cells. Cell-specific CD68 expression and differentiated expression levels are determined by the complex interplay between transcription factors, regulatory transcriptional elements, and epigenetic factors. Human CD68 and its mouse ortholog macrosialin belong to the family of LAMP proteins located in the lysosomal membrane and share many structural similarities such as the presence of the LAMP-like domain. Except for a second LAMP-like domain present in LAMPs, CD68/microsialin has a highly glycosylated mucin-like domain involved in ligand binding. CD68 has been shown to bind oxLDL, phosphatidylserine, apoptotic cells and serve as a receptor for malaria sporozoite in liver infection. CD68 is mainly located in the endosomal/lysosomal compartment but can rapidly shuttle to the cell surface. However, the role of CD68 as a scavenger receptor remains to be confirmed. It seems that CD68 is not involved in binding bacterial/viral pathogens, innate, inflammatory or humoral immune responses, although it may potentially be involved in antigen processing/presentation. CD68 could be functionally important in osteoclasts since its deletion leads to reduced bone resorption capacity. The role of CD68 in atherosclerosis is contradictory.
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Peng H, Li H, Sheehy A, Cullen P, Allaire N, Scannevin RH. Dimethyl fumarate alters microglia phenotype and protects neurons against proinflammatory toxic microenvironments. J Neuroimmunol 2016; 299:35-44. [DOI: 10.1016/j.jneuroim.2016.08.006] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 08/03/2016] [Accepted: 08/04/2016] [Indexed: 12/15/2022]
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Forced treadmill exercise can induce stress and increase neuronal damage in a mouse model of global cerebral ischemia. Neurobiol Stress 2016; 5:8-18. [PMID: 27981192 PMCID: PMC5145912 DOI: 10.1016/j.ynstr.2016.09.002] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Revised: 08/24/2016] [Accepted: 09/07/2016] [Indexed: 12/19/2022] Open
Abstract
Physical exercise is known to be a beneficial factor by increasing the cellular stress tolerance. In ischemic stroke, physical exercise is suggested to both limit the brain injury and facilitate behavioral recovery. In this study we investigated the effect of physical exercise on brain damage following global cerebral ischemia in mice. We aimed to study the effects of 4.5 weeks of forced treadmill running prior to ischemia on neuronal damage, neuroinflammation and its effect on general stress by measuring corticosterone in feces. We subjected C57bl/6 mice (n = 63) to either treadmill running or a sedentary program prior to induction of global ischemia. Anxious, depressive, and cognitive behaviors were analyzed. Stress levels were analyzed using a corticosterone ELISA. Inflammatory and neurological outcomes were analyzed using immunohistochemistry, multiplex electrochemoluminescence ELISA and Western blot. To our surprise, we found that forced treadmill running induced a stress response, with increased anxiety in the Open Field test and increased levels of corticosterone. In accordance, mice subjected to forced exercise prior to ischemia developed larger neuronal damage in the hippocampus and showed higher cytokine levels in the brain and blood compared to non-exercised mice. The extent of neuronal damage correlated with increased corticosterone levels. To compare forced treadmill with voluntary wheel running, we used a different set of mice that exercised freely on running wheels. These mice did not show any anxiety or increased corticosterone levels. Altogether, our results indicate that exercise pre-conditioning may not be beneficial if the animals are forced to run as it can induce a detrimental stress response. Enforcement to run results in anxious behavior. Mice that are forced to run have elevated levels of corticosterone. Enforcement to run results in more neuronal death in hippocampus. Corticosterone levels correlates with the neuronal damage in hippocampus. Increased corticosterone and anxiety is not seen in mice that run voluntarily.
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Carbon monoxide treatment reduces microglial activation in the ischemic rat retina. Graefes Arch Clin Exp Ophthalmol 2016; 254:1967-1976. [PMID: 27443355 DOI: 10.1007/s00417-016-3435-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Revised: 06/06/2016] [Accepted: 07/04/2016] [Indexed: 12/21/2022] Open
Abstract
PURPOSE Ischemia and reperfusion (I/R) injury damages retinal neurons. Retinal injury is accompanied by activation of microglia, which scavenge the dead or dying neurons, but increasing evidence now indicates that amoeboid-shaped microglia cells activated in the brain after ischemia have neurotoxic and damaging properties in their own right. A previous study showed that postconditioning with carbon monoxide (CO) protects retinal ganglion cells (RGCs) after I/R through anti-apoptotic and anti-inflammatory mechanisms. The present study was designed to investigate and quantify the activation of retinal microglia after I/R with and without CO postconditioning. METHODS Adult Sprague-Dawley rats underwent retinal ischemia by increasing the ocular pressure to 120 mmHg for 1 h through a needle inserted into the anterior chamber. Reperfusion was induced by removing the needle. After I/R, one group of animals was kept in a CO (250 ppm) atmosphere for 1 h; the other group was kept in room air (Air). At 1, 2, 3, and 7 days after I/R, the eyes were enucleated and fixed. Intracardiac blood was analyzed for systemic effects of CO or I/R. Retinal cross sections were taken from the middle third of the eye and were stained with anti-Iba-1. Microglia cells were graded as amoeboid or ramified phenotypes according to morphologic criteria. Retinal thicknesses were determined. RESULTS Evaluation of retinal tissue revealed a significant reduction of amoeboid microglia cells after I/R + CO when compared to the I/R + Air group. The peak number of amoeboid microglia was observed at day 2 post-I/R + Air. This rise was attenuated by CO postconditioning (815 versus 572 cells/mm2 for I/R + Air versus I/R + CO, respectively; p = 0.005). CO reduced and further postponed the peak in the numbers of amoeboid and ramified microglia cells in ischemic eyes and prevented microglial activation in the contralateral eyes. I/R-induced leucocytosis was inhibited by CO inhalation. The reduction of retinal thickness after I/R was more serious after Air inhalation when compared to the CO group. CONCLUSIONS Numerous activated microglia cells appear in the inner retina after I/R, and CO-treatment significantly attenuates this glial response. Antagonism of microglial activation may be a further neuroprotective effect of CO, apart from its direct anti-apoptotic capacity.
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Kann O, Hollnagel JO, Elzoheiry S, Schneider J. Energy and Potassium Ion Homeostasis during Gamma Oscillations. Front Mol Neurosci 2016; 9:47. [PMID: 27378847 PMCID: PMC4909733 DOI: 10.3389/fnmol.2016.00047] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 05/30/2016] [Indexed: 12/21/2022] Open
Abstract
Fast neuronal network oscillations in the gamma frequency band (30-100 Hz) occur in various cortex regions, require timed synaptic excitation and inhibition with glutamate and GABA, respectively, and are associated with higher brain functions such as sensory perception, attentional selection and memory formation. However, little is known about energy and ion homeostasis during the gamma oscillation. Recent studies addressed this topic in slices of the rodent hippocampus using cholinergic and glutamatergic receptor models of gamma oscillations (GAM). Methods with high spatial and temporal resolution were applied in vitro, such as electrophysiological recordings of local field potential (LFP) and extracellular potassium concentration ([K(+)]o), live-cell fluorescence imaging of nicotinamide adenine dinucleotide (phosphate) and flavin adenine dinucleotide [NAD(P)H and FAD, respectively] (cellular redox state), and monitoring of the interstitial partial oxygen pressure (pO2) in depth profiles with microsensor electrodes, including mathematical modeling. The main findings are: (i) GAM are associated with high oxygen consumption rate and significant changes in the cellular redox state, indicating rapid adaptations in glycolysis and oxidative phosphorylation; (ii) GAM are accompanied by fluctuating elevations in [K(+)]o of less than 0.5 mmol/L from baseline, likely reflecting effective K(+)-uptake mechanisms of neuron and astrocyte compartments; and (iii) GAM are exquisitely sensitive to metabolic stress induced by lowering oxygen availability or by pharmacological inhibition of the mitochondrial respiratory chain. These findings reflect precise cellular adaptations to maintain adenosine-5'-triphosphate (ATP), ion and neurotransmitter homeostasis and thus neural excitability and synaptic signaling during GAM. Conversely, the exquisite sensitivity of GAM to metabolic stress might significantly contribute the exceptional vulnerability of higher brain functions in brain disease.
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Affiliation(s)
- Oliver Kann
- Institute of Physiology and Pathophysiology, University of HeidelbergHeidelberg, Germany; Interdisciplinary Center for Neurosciences (IZN), University of HeidelbergHeidelberg, Germany
| | - Jan-Oliver Hollnagel
- Institute of Physiology and Pathophysiology, University of HeidelbergHeidelberg, Germany; Interdisciplinary Center for Neurosciences (IZN), University of HeidelbergHeidelberg, Germany
| | - Shehabeldin Elzoheiry
- Institute of Physiology and Pathophysiology, University of HeidelbergHeidelberg, Germany; Interdisciplinary Center for Neurosciences (IZN), University of HeidelbergHeidelberg, Germany
| | - Justus Schneider
- Institute of Physiology and Pathophysiology, University of HeidelbergHeidelberg, Germany; Interdisciplinary Center for Neurosciences (IZN), University of HeidelbergHeidelberg, Germany
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Abstract
AbstractNatural bornavirus infections and their resulting diseases are largely restricted to horses and sheep in Central Europe. The disease also occurs naturally in cats, and can be induced experimentally in laboratory rodents and numerous other mammals. Borna disease virus-1 (BoDV-1), the cause of most cases of mammalian Borna disease, is a negative-stranded RNA virus that replicates within the nucleus of target cells. It causes severe, often lethal, encephalitis in susceptible species. Recent events, especially the discovery of numerous new species of bornaviruses in birds and a report of an acute, lethal bornaviral encephalitis in humans, apparently acquired from squirrels, have revived interest in this remarkable family of viruses. The clinical manifestations of the bornaviral diseases are highly variable. Thus, in addition to acute lethal encephalitis, they can cause persistent neurologic disease associated with diverse behavioral changes. They also cause a severe retinitis resulting in blindness. In this review, we discuss both the pathological lesions observed in mammalian bornaviral disease and the complex pathogenesis of the neurologic disease. Thus infected neurons may be destroyed by T-cell-mediated cytotoxicity. They may die as a result of excessive inflammatory cytokine release from microglia. They may also die as a result of a ‘glutaminergic storm’ due to a failure of infected astrocytes to regulate brain glutamate levels.
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