151
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Mesnil M, Defamie N, Naus C, Sarrouilhe D. Brain Disorders and Chemical Pollutants: A Gap Junction Link? Biomolecules 2020; 11:51. [PMID: 33396565 PMCID: PMC7824109 DOI: 10.3390/biom11010051] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 12/22/2020] [Accepted: 12/23/2020] [Indexed: 02/07/2023] Open
Abstract
The incidence of brain pathologies has increased during last decades. Better diagnosis (autism spectrum disorders) and longer life expectancy (Parkinson's disease, Alzheimer's disease) partly explain this increase, while emerging data suggest pollutant exposures as a possible but still underestimated cause of major brain disorders. Taking into account that the brain parenchyma is rich in gap junctions and that most pollutants inhibit their function; brain disorders might be the consequence of gap-junctional alterations due to long-term exposures to pollutants. In this article, this hypothesis is addressed through three complementary aspects: (1) the gap-junctional organization and connexin expression in brain parenchyma and their function; (2) the effect of major pollutants (pesticides, bisphenol A, phthalates, heavy metals, airborne particles, etc.) on gap-junctional and connexin functions; (3) a description of the major brain disorders categorized as neurodevelopmental (autism spectrum disorders, attention deficit hyperactivity disorders, epilepsy), neurobehavioral (migraines, major depressive disorders), neurodegenerative (Parkinson's and Alzheimer's diseases) and cancers (glioma), in which both connexin dysfunction and pollutant involvement have been described. Based on these different aspects, the possible involvement of pollutant-inhibited gap junctions in brain disorders is discussed for prenatal and postnatal exposures.
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Affiliation(s)
- Marc Mesnil
- Laboratoire STIM, ERL7003 CNRS-Université de Poitiers, 1 rue G. Bonnet–TSA 51 106, 86073 Poitiers, France; (M.M.); (N.D.)
| | - Norah Defamie
- Laboratoire STIM, ERL7003 CNRS-Université de Poitiers, 1 rue G. Bonnet–TSA 51 106, 86073 Poitiers, France; (M.M.); (N.D.)
| | - Christian Naus
- Faculty of Medicine, Department of Cellular & Physiological Sciences, Life Sciences Institute, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T1Z3, Canada;
| | - Denis Sarrouilhe
- Laboratoire de Physiologie Humaine, Faculté de Médecine et Pharmacie, 6 rue de La Milétrie, bât D1, TSA 51115, 86073 Poitiers, France
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152
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Lenz M, Eichler A, Kruse P, Strehl A, Rodriguez-Rozada S, Goren I, Yogev N, Frank S, Waisman A, Deller T, Jung S, Maggio N, Vlachos A. Interleukin 10 Restores Lipopolysaccharide-Induced Alterations in Synaptic Plasticity Probed by Repetitive Magnetic Stimulation. Front Immunol 2020; 11:614509. [PMID: 33391287 PMCID: PMC7772211 DOI: 10.3389/fimmu.2020.614509] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 11/16/2020] [Indexed: 12/26/2022] Open
Abstract
Systemic inflammation is associated with alterations in complex brain functions such as learning and memory. However, diagnostic approaches to functionally assess and quantify inflammation-associated alterations in synaptic plasticity are not well-established. In previous work, we demonstrated that bacterial lipopolysaccharide (LPS)-induced systemic inflammation alters the ability of hippocampal neurons to express synaptic plasticity, i.e., the long-term potentiation (LTP) of excitatory neurotransmission. Here, we tested whether synaptic plasticity induced by repetitive magnetic stimulation (rMS), a non-invasive brain stimulation technique used in clinical practice, is affected by LPS-induced inflammation. Specifically, we explored brain tissue cultures to learn more about the direct effects of LPS on neural tissue, and we tested for the plasticity-restoring effects of the anti-inflammatory cytokine interleukin 10 (IL10). As shown previously, 10 Hz repetitive magnetic stimulation (rMS) of organotypic entorhino-hippocampal tissue cultures induced a robust increase in excitatory neurotransmission onto CA1 pyramidal neurons. Furthermore, LPS-treated tissue cultures did not express rMS-induced synaptic plasticity. Live-cell microscopy in tissue cultures prepared from a novel transgenic reporter mouse line [C57BL/6-Tg(TNFa-eGFP)] confirms that ex vivo LPS administration triggers microglial tumor necrosis factor alpha (TNFα) expression, which is ameliorated in the presence of IL10. Consistent with this observation, IL10 hampers the LPS-induced increase in TNFα, IL6, IL1β, and IFNγ and restores the ability of neurons to express rMS-induced synaptic plasticity in the presence of LPS. These findings establish organotypic tissue cultures as a suitable model for studying inflammation-induced alterations in synaptic plasticity, thus providing a biological basis for the diagnostic use of transcranial magnetic stimulation in the context of brain inflammation.
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Affiliation(s)
- Maximilian Lenz
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Amelie Eichler
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Pia Kruse
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Andreas Strehl
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe-University Frankfurt, Frankfurt, Germany
| | - Silvia Rodriguez-Rozada
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe-University Frankfurt, Frankfurt, Germany
| | - Itamar Goren
- Pharmazentrum Frankfurt/ZAFES, Goethe-University Frankfurt, Frankfurt, Germany
| | - Nir Yogev
- Institute for Molecular Medicine, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
- Department of Dermatology, Faculty of Medicine, University of Cologne, Cologne, Germany
| | - Stefan Frank
- Pharmazentrum Frankfurt/ZAFES, Goethe-University Frankfurt, Frankfurt, Germany
| | - Ari Waisman
- Institute for Molecular Medicine, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Thomas Deller
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe-University Frankfurt, Frankfurt, Germany
| | - Steffen Jung
- Department of Immunology, Weizmann Institute of Science, Rehovot, Israel
| | - Nicola Maggio
- Department of Neurology and Sagol Center for Neurosciences, Talpiot Medical Leadership Program, The Chaim Sheba Medical Center, Tel HaShomer, Israel
- Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Andreas Vlachos
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Center Brain Links Brain Tools, University of Freiburg, Freiburg, Germany
- Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany
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153
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Ung MC, Garrett L, Dalke C, Leitner V, Dragosa D, Hladik D, Neff F, Wagner F, Zitzelsberger H, Miller G, de Angelis MH, Rößler U, Vogt Weisenhorn D, Wurst W, Graw J, Hölter SM. Dose-dependent long-term effects of a single radiation event on behaviour and glial cells. Int J Radiat Biol 2020; 97:156-169. [PMID: 33264576 DOI: 10.1080/09553002.2021.1857455] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
PURPOSE The increasing use of low-dose ionizing radiation in medicine requires a systematic study of its long-term effects on the brain, behaviour and its possible association with neurodegenerative disease vulnerability. Therefore, we analysed the long-term effects of a single low-dose irradiation exposure at 10 weeks of age compared to medium and higher doses on locomotor, emotion-related and sensorimotor behaviour in mice as well as on hippocampal glial cell populations. MATERIALS AND METHODS We determined the influence of radiation dose (0, 0.063, 0.125 or 0.5 Gy), time post-irradiation (4, 12 and 18 months p.i.), sex and genotype (wild type versus mice with Ercc2 DNA repair gene point mutation) on behaviour. RESULTS The high dose (0.5 Gy) had early-onset adverse effects at 4 months p.i. on sensorimotor recruitment and late-onset negative locomotor effects at 12 and 18 months p.i. Notably, the low dose (0.063 Gy) produced no early effects but subtle late-onset (18 months) protective effects on sensorimotor recruitment and exploratory behaviour. Quantification and morphological characterization of the microglial and the astrocytic cells of the dentate gyrus 24 months p.i. indicated heightened immune activity after high dose irradiation (0.125 and 0.5 Gy) while conversely, low dose (0.063 Gy) induced more neuroprotective features. CONCLUSION This is one of the first studies demonstrating such long-term and late-onset effects on brain and behaviour after a single radiation event in adulthood.
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Affiliation(s)
- Marie-Claire Ung
- Institute of Developmental Genetics, Helmholtz Zentrum München, German Research Centre for Environmental Health, Neuherberg, Germany.,Institute of Pathology, Helmholtz Zentrum München, German Research Centre for Environmental Health, Neuherberg, Germany.,Institute of Radiation Medicine, Helmholtz Zentrum München, German Research Centre for Environmental Health, Neuherberg, Germany.,Research Unit of Radiation Cytogenetics, Helmholtz Zentrum München, German Research Centre for Environmental Health, Neuherberg, Germany.,German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Centre for Environmental Health, Neuherberg, Germany
| | - Lillian Garrett
- Institute of Developmental Genetics, Helmholtz Zentrum München, German Research Centre for Environmental Health, Neuherberg, Germany.,German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Centre for Environmental Health, Neuherberg, Germany
| | - Claudia Dalke
- Institute of Developmental Genetics, Helmholtz Zentrum München, German Research Centre for Environmental Health, Neuherberg, Germany
| | | | - Daniel Dragosa
- Technische Universität München, Freising-Weihenstephan, Germany
| | - Daniela Hladik
- Technische Universität München, Freising-Weihenstephan, Germany
| | - Frauke Neff
- Institute of Pathology, Helmholtz Zentrum München, German Research Centre for Environmental Health, Neuherberg, Germany
| | - Florian Wagner
- Institute of Radiation Medicine, Helmholtz Zentrum München, German Research Centre for Environmental Health, Neuherberg, Germany
| | - Horst Zitzelsberger
- Research Unit of Radiation Cytogenetics, Helmholtz Zentrum München, German Research Centre for Environmental Health, Neuherberg, Germany
| | - Gregor Miller
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Centre for Environmental Health, Neuherberg, Germany
| | - Martin Hrabĕ de Angelis
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Centre for Environmental Health, Neuherberg, Germany.,Department of Experimental Genetics, School of Life Science Weihenstephan, Technische Universität München, Freising, Germany.,German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Ute Rößler
- Federal Office for Radiation Protection, Department of Radiation Protection and Health, Neuherberg, Germany
| | - Daniela Vogt Weisenhorn
- Institute of Developmental Genetics, Helmholtz Zentrum München, German Research Centre for Environmental Health, Neuherberg, Germany
| | - Wolfgang Wurst
- Institute of Developmental Genetics, Helmholtz Zentrum München, German Research Centre for Environmental Health, Neuherberg, Germany.,Chair of Developmental Genetics, Faculty of Life and Food Sciences Weihenstephan, Technische Universität München, Freising-Weihenstephan, Germany.,German Center for Neurodegenerative Diseases (DZNE), Site Munich, Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Jochen Graw
- Institute of Developmental Genetics, Helmholtz Zentrum München, German Research Centre for Environmental Health, Neuherberg, Germany
| | - Sabine M Hölter
- Institute of Developmental Genetics, Helmholtz Zentrum München, German Research Centre for Environmental Health, Neuherberg, Germany.,German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Centre for Environmental Health, Neuherberg, Germany.,Technische Universität München, Freising-Weihenstephan, Germany
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154
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Stolero N, Frenkel D. The dialog between neurons and microglia in Alzheimer's disease: The neurotransmitters view. J Neurochem 2020; 158:1412-1424. [PMID: 33314073 DOI: 10.1111/jnc.15262] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2020] [Revised: 11/12/2020] [Accepted: 12/04/2020] [Indexed: 02/06/2023]
Abstract
Microglia play a vital role in maintaining brain homeostasis. Their continuous sensing of surrounding micro-environments is crucial for their activity. Cross talk between specific neurons and microglia might occur through specific neurotransmitter receptors on microglia. Impairment with this interaction might result in pathological activity of microglia against potential insults. The reason for this activity in many neurodegenerative diseases such as Alzheimer's disease (AD) is not known. However, several papers report of the effects of different neurotransmitter agonists on microglial cells function that relate to their activity in AD. This review aims to summarize those works and to raise potential fundamental questions for future research.
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Affiliation(s)
- Nofar Stolero
- Department of Neurobiology, School of Neurobiology, Biochemistry and Biophysics School, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Dan Frenkel
- Department of Neurobiology, School of Neurobiology, Biochemistry and Biophysics School, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel.,Sagol School of Neuroscience, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
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155
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Keck T. Microglia Tweak Retinogeniculate Pathways during Visual Circuit Refinement. Neuron 2020; 108:397-399. [PMID: 33181071 DOI: 10.1016/j.neuron.2020.10.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Cheadle et al. reveal that microglia expressing TWEAK facilitate synapse elimination through a novel, non-phagocytic mechanism in the retinogeniculate pathway during visual circuit development. This mechanism is experience-dependent and occurs through the local binding of TWEAK to postsynaptic Fn14.
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Affiliation(s)
- Tara Keck
- Department of Neuroscience, Physiology and Pharmacology, University College London, 21 University St., London WC1E 6DE, UK.
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156
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Rexach JE, Polioudakis D, Yin A, Swarup V, Chang TS, Nguyen T, Sarkar A, Chen L, Huang J, Lin LC, Seeley W, Trojanowski JQ, Malhotra D, Geschwind DH. Tau Pathology Drives Dementia Risk-Associated Gene Networks toward Chronic Inflammatory States and Immunosuppression. Cell Rep 2020; 33:108398. [PMID: 33207193 PMCID: PMC7842189 DOI: 10.1016/j.celrep.2020.108398] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 06/29/2020] [Accepted: 10/26/2020] [Indexed: 12/31/2022] Open
Abstract
To understand how neural-immune-associated genes and pathways contribute to neurodegenerative disease pathophysiology, we performed a systematic functional genomic analysis in purified microglia and bulk tissue from mouse and human AD, FTD, and PSP. We uncover a complex temporal trajectory of microglial-immune pathways involving the type 1 interferon response associated with tau pathology in the early stages, followed by later signatures of partial immune suppression and, subsequently, the type 2 interferon response. We find that genetic risk for dementias shows disease-specific patterns of pathway enrichment. We identify drivers of two gene co-expression modules conserved from mouse to human, representing competing arms of microglial-immune activation (NAct) and suppression (NSupp) in neurodegeneration. We validate our findings by using chemogenetics, experimental perturbation data, and single-cell sequencing in post-mortem brains. Our results refine the understanding of stage- and disease-specific microglial responses, implicate microglial viral defense pathways in dementia pathophysiology, and highlight therapeutic windows. Rexach et al. use transcriptional network analysis to define dynamic microglial transitions across neurodegeneration, discovering that three dementias with tau pathology involve dysregulated microglial viral and antiviral pathways. Bio-informatics coupled with experimental validation identifies regulatory drivers, implicating double-stranded RNA and interferon-response genes as drivers of early immune suppression in disease.
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Affiliation(s)
- Jessica E Rexach
- Program in Neurogenetics, Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Damon Polioudakis
- Program in Neurogenetics, Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Anna Yin
- Program in Neurogenetics, Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Vivek Swarup
- Program in Neurogenetics, Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Timothy S Chang
- Program in Neurogenetics, Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Tam Nguyen
- Program in Neurogenetics, Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Arjun Sarkar
- Program in Neurogenetics, Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Lawrence Chen
- Program in Neurogenetics, Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Jerry Huang
- Program in Neurogenetics, Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Li-Chun Lin
- Department of Pathology, University of California, San Francisco, San Francisco, CA, USA
| | - William Seeley
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, San Francisco, CA, USA; Department of Pathology, University of California, San Francisco, San Francisco, CA, USA
| | - John Q Trojanowski
- Department of Pathology & Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Dheeraj Malhotra
- Neuroscience and Rare Diseases, Roche Pharma Research and Early Development, F. Hoffman-LaRoche, Basel, Switzerland
| | - Daniel H Geschwind
- Program in Neurogenetics, Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA; Institute of Precision Health, University of California, Los Angeles, Los Angeles, CA 90095, USA.
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157
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Purinergic signaling orchestrating neuron-glia communication. Pharmacol Res 2020; 162:105253. [PMID: 33080321 DOI: 10.1016/j.phrs.2020.105253] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 09/29/2020] [Accepted: 10/09/2020] [Indexed: 12/12/2022]
Abstract
This review discusses the evidence supporting a role for ATP signaling (operated by P2X and P2Y receptors) and adenosine signaling (mainly operated by A1 and A2A receptors) in the crosstalk between neurons, astrocytes, microglia and oligodendrocytes. An initial emphasis will be given to the cooperation between adenosine receptors to sharpen information salience encoding across synapses. The interplay between ATP and adenosine signaling in the communication between astrocytes and neurons will then be presented in context of the integrative properties of the astrocytic syncytium, allowing to implement heterosynaptic depression processes in neuronal networks. The process of microglia 'activation' and its control by astrocytes and neurons will then be analyzed under the perspective of an interplay between different P2 receptors and adenosine A2A receptors. In spite of these indications of a prominent role of purinergic signaling in the bidirectional communication between neurons and glia, its therapeutical exploitation still awaits obtaining an integrated view of the spatio-temporal action of ATP signaling and adenosine signaling, clearly distinguishing the involvement of both purinergic signaling systems in the regulation of physiological processes and in the control of pathogenic-like responses upon brain dysfunction or damage.
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158
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Wu W, Li Y, Wei Y, Bosco DB, Xie M, Zhao MG, Richardson JR, Wu LJ. Microglial depletion aggravates the severity of acute and chronic seizures in mice. Brain Behav Immun 2020; 89:245-255. [PMID: 32621847 PMCID: PMC7572576 DOI: 10.1016/j.bbi.2020.06.028] [Citation(s) in RCA: 76] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 06/12/2020] [Accepted: 06/24/2020] [Indexed: 01/03/2023] Open
Abstract
Microglia are the resident immune cells of the center nervous system and participate in various neurological diseases. Here we determined the function of microglia in epileptogenesis using microglial ablation approaches. Three different microglia-specific genetic tools were used, CX3CR1CreER/+:R26iDTA/+, CX3CR1CreER/+:R26iDTR/+, and CX3CR1CreER/+:Csf1rFlox/Flox mice. We found that microglial depletion led to worse kainic acid (KA)-induced status epilepticus, higher mortality rate, and increased neuronal degeneration in the hippocampus. In KA-induced chronic spontaneous recurrent seizures, microglial depletion increased seizure frequency, interictal spiking, and seizure duration. Therefore, microglial depletion aggravates the severity of KA-induced acute and chronic seizures. Interestingly, microglial repopulation reversed the effects of depletion upon KA-induced status epilepticus. Our results demonstrate a beneficial role of microglia in suppressing both acute and chronic seizures, suggesting that microglia are a potential therapeutic target for the management of epilepsy.
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Affiliation(s)
- Wenning Wu
- Department of Pharmacology, School of Basic Medical Sciences, Anhui Medical University, Hefei 230032, China; Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA
| | - Yujiao Li
- Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA; Department of Pharmacy, Tangdu Hospital, Fourth Military Medical University, Xi'an 710038, China
| | - Yujia Wei
- Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA
| | - Dale B Bosco
- Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA
| | - Manling Xie
- Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA
| | - Ming-Gao Zhao
- Department of Pharmacy, Tangdu Hospital, Fourth Military Medical University, Xi'an 710038, China
| | - Jason R Richardson
- Department of Environmental Health Sciences, Florida International University, Miami, FL 33199, USA
| | - Long-Jun Wu
- Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA; Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224, USA; Departments of Immunology, Mayo Clinic, Rochester, MN 55905, USA.
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159
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Carrier M, Robert MÈ, González Ibáñez F, Desjardins M, Tremblay MÈ. Imaging the Neuroimmune Dynamics Across Space and Time. Front Neurosci 2020; 14:903. [PMID: 33071723 PMCID: PMC7539119 DOI: 10.3389/fnins.2020.00903] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 08/04/2020] [Indexed: 12/13/2022] Open
Abstract
The immune system is essential for maintaining homeostasis, as well as promoting growth and healing throughout the brain and body. Considering that immune cells respond rapidly to changes in their microenvironment, they are very difficult to study without affecting their structure and function. The advancement of non-invasive imaging methods greatly contributed to elucidating the physiological roles performed by immune cells in the brain across stages of the lifespan and contexts of health and disease. For instance, techniques like two-photon in vivo microscopy were pivotal for studying microglial functional dynamics in the healthy brain. Through these observations, their interactions with neurons, astrocytes, blood vessels and synapses were uncovered. High-resolution electron microscopy with immunostaining and 3D-reconstruction, as well as super-resolution fluorescence microscopy, provided complementary insights by revealing microglial interventions at synapses (phagocytosis, trogocytosis, synaptic stripping, etc.). In addition, serial block-face scanning electron microscopy has provided the first 3D reconstruction of a microglial cell at nanoscale resolution. This review will discuss the technical toolbox that currently allows to study microglia and other immune cells in the brain, as well as introduce emerging methods that were developed and could be used to increase the spatial and temporal resolution of neuroimmune imaging. A special attention will also be placed on positron emission tomography and the development of selective functional radiotracers for microglia and peripheral macrophages, considering their strong potential for research translation between animals and humans, notably when paired with other imaging modalities such as magnetic resonance imaging.
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Affiliation(s)
- Micaël Carrier
- Axe Neurosciences, Centre de Recherche du CHU de Québec, Université Laval, Québec City, QC, Canada
| | - Marie-Ève Robert
- Axe Neurosciences, Centre de Recherche du CHU de Québec, Université Laval, Québec City, QC, Canada
| | - Fernando González Ibáñez
- Axe Neurosciences, Centre de Recherche du CHU de Québec, Université Laval, Québec City, QC, Canada
| | - Michèle Desjardins
- Axe Oncologie, Centre de Recherche du CHU de Québec, Université Laval, Québec City, QC, Canada
- Department of Physics, Physical Engineering and Optics, Université Laval, Québec City, QC, Canada
| | - Marie-Ève Tremblay
- Axe Neurosciences, Centre de Recherche du CHU de Québec, Université Laval, Québec City, QC, Canada
- Department of Molecular Medicine, Université Laval, Québec City, QC, Canada
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
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160
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Zimmer TS, Broekaart DWM, Gruber VE, van Vliet EA, Mühlebner A, Aronica E. Tuberous Sclerosis Complex as Disease Model for Investigating mTOR-Related Gliopathy During Epileptogenesis. Front Neurol 2020; 11:1028. [PMID: 33041976 PMCID: PMC7527496 DOI: 10.3389/fneur.2020.01028] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Accepted: 08/06/2020] [Indexed: 12/13/2022] Open
Abstract
Tuberous sclerosis complex (TSC) represents the prototypic monogenic disorder of the mammalian target of rapamycin (mTOR) pathway dysregulation. It provides the rational mechanistic basis of a direct link between gene mutation and brain pathology (structural and functional abnormalities) associated with a complex clinical phenotype including epilepsy, autism, and intellectual disability. So far, research conducted in TSC has been largely neuron-oriented. However, the neuropathological hallmarks of TSC and other malformations of cortical development also include major morphological and functional changes in glial cells involving astrocytes, oligodendrocytes, NG2 glia, and microglia. These cells and their interglial crosstalk may offer new insights into the common neurobiological mechanisms underlying epilepsy and the complex cognitive and behavioral comorbidities that are characteristic of the spectrum of mTOR-associated neurodevelopmental disorders. This review will focus on the role of glial dysfunction, the interaction between glia related to mTOR hyperactivity, and its contribution to epileptogenesis in TSC. Moreover, we will discuss how understanding glial abnormalities in TSC might give valuable insight into the pathophysiological mechanisms that could help to develop novel therapeutic approaches for TSC or other pathologies characterized by glial dysfunction and acquired mTOR hyperactivation.
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Affiliation(s)
- Till S Zimmer
- Department of (Neuro)Pathology, Amsterdam Neuroscience, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, Netherlands
| | - Diede W M Broekaart
- Department of (Neuro)Pathology, Amsterdam Neuroscience, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, Netherlands
| | | | - Erwin A van Vliet
- Department of (Neuro)Pathology, Amsterdam Neuroscience, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, Netherlands.,Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, Amsterdam, Netherlands
| | - Angelika Mühlebner
- Department of (Neuro)Pathology, Amsterdam Neuroscience, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, Netherlands
| | - Eleonora Aronica
- Department of (Neuro)Pathology, Amsterdam Neuroscience, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, Netherlands.,Stichting Epilepsie Instellingen Nederland (SEIN), Heemstede, Netherlands
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161
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Grigorovsky V, Breton VL, Bardakjian BL. Glial Modulation of Electrical Rhythms in a Neuroglial Network Model of Epilepsy. IEEE Trans Biomed Eng 2020; 68:2076-2087. [PMID: 32894704 DOI: 10.1109/tbme.2020.3022332] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE An important EEG-based biomarker for epilepsy is the phase-amplitude cross-frequency coupling (PAC) of electrical rhythms; however, the underlying pathways of these pathologic markers are not always clear. Since glial cells have been shown to play an active role in neuroglial networks, it is likely that some of these PAC markers are modulated via glial effects. METHODS We developed a 4-unit hybrid model of a neuroglial network, consisting of 16 sub-units, that combines a mechanistic representation of neurons with an oscillator-based Cognitive Rhythm Generator (CRG) representation of glial cells-astrocytes and microglia. The model output was compared with recorded generalized tonic-clonic patient data, both in terms of PAC features, and state classification using an unsupervised hidden Markov model (HMM). RESULTS The neuroglial model output showed PAC features similar to those observed in epileptic seizures. These generated PAC features were able to accurately identify spontaneous epileptiform discharges (SEDs) as seizure-like states, as well as a postictal-like state following the long-duration SED, when applied to the HMM machine learning algorithm trained on patient data. The evolution profile of the maximal PAC during the SED compared well with patient data, showing similar association with the duration of the postictal state. CONCLUSION The hybrid neuroglial network model was able to generate PAC features similar to those observed in ictal and postictal epileptic states, which has been used for state classification and postictal state duration prediction. SIGNIFICANCE Since PAC biomarkers are important for epilepsy research and postictal state duration has been linked with risk of sudden unexplained death in epilepsy, this model suggests glial synaptic effects as potential targets for further analysis and treatment.
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Koller EJ, Chakrabarty P. Tau-Mediated Dysregulation of Neuroplasticity and Glial Plasticity. Front Mol Neurosci 2020; 13:151. [PMID: 32973446 PMCID: PMC7472665 DOI: 10.3389/fnmol.2020.00151] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 07/20/2020] [Indexed: 01/14/2023] Open
Abstract
The inability of individual neurons to compensate for aging-related damage leads to a gradual loss of functional plasticity in the brain accompanied by progressive impairment in learning and memory. Whereas this loss in neuroplasticity is gradual during normal aging, in neurodegenerative diseases such as Alzheimer’s disease (AD), this loss is accelerated dramatically, leading to the incapacitation of patients within a decade of onset of cognitive symptoms. The mechanisms that underlie this accelerated loss of neuroplasticity in AD are still not completely understood. While the progressively increasing proteinopathy burden, such as amyloid β (Aβ) plaques and tau tangles, definitely contribute directly to a neuron’s functional demise, the role of non-neuronal cells in controlling neuroplasticity is slowly being recognized as another major factor. These non-neuronal cells include astrocytes, microglia, and oligodendrocytes, which through regulating brain homeostasis, structural stability, and trophic support, play a key role in maintaining normal functioning and resilience of the neuronal network. It is believed that chronic signaling from these cells affects the homeostatic network of neuronal and non-neuronal cells to an extent to destabilize this harmonious milieu in neurodegenerative diseases like AD. Here, we will examine the experimental evidence regarding the direct and indirect pathways through which astrocytes and microglia can alter brain plasticity in AD, specifically as they relate to the development and progression of tauopathy. In this review article, we describe the concepts of neuroplasticity and glial plasticity in healthy aging, delineate possible mechanisms underlying tau-induced plasticity dysfunction, and discuss current clinical trials as well as future disease-modifying approaches.
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Affiliation(s)
- Emily J Koller
- Department of Neuroscience, University of Florida, Gainesville, FL, United States.,Center for Translational Research in Neurodegenerative Disease, University of Florida, Gainesville, FL, United States
| | - Paramita Chakrabarty
- Department of Neuroscience, University of Florida, Gainesville, FL, United States.,Center for Translational Research in Neurodegenerative Disease, University of Florida, Gainesville, FL, United States.,McKnight Brain Institute, University of Florida, Gainesville, FL, United States
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163
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Fatoba O, Itokazu T, Yamashita T. Microglia as therapeutic target in central nervous system disorders. J Pharmacol Sci 2020; 144:102-118. [PMID: 32921391 DOI: 10.1016/j.jphs.2020.07.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 05/19/2020] [Accepted: 07/07/2020] [Indexed: 12/17/2022] Open
Abstract
Chronic microglial activation is associated with the pathogenesis of several CNS disorders. Microglia show phenotypic diversity and functional complexity in diseased CNS. Thus, understanding the pathology-specific heterogeneity of microglial behavior is crucial for the future development of microglia-modulating therapy for variety of CNS disorders. This review summarizes up-to-date knowledge on how microglia contribute to CNS homeostasis during development and throughout adulthood. We discuss the heterogeneity of microglial phenotypes in the context of CNS disorders with an emphasis on neurodegenerative diseases, demyelinating diseases, CNS trauma, and epilepsy. We conclude this review with a discussion about the disease-specific heterogeneity of microglial function and how it could be exploited for therapeutic intervention.
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Affiliation(s)
- Oluwaseun Fatoba
- Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan; WPI-Immunology Frontier Research Center, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
| | - Takahide Itokazu
- Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan; Department of Neuro-Medical Science, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Toshihide Yamashita
- Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan; WPI-Immunology Frontier Research Center, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan; Department of Neuro-Medical Science, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.
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164
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Rudzki L, Maes M. The Microbiota-Gut-Immune-Glia (MGIG) Axis in Major Depression. Mol Neurobiol 2020; 57:4269-4295. [DOI: 10.1007/s12035-020-01961-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 05/28/2020] [Indexed: 02/08/2023]
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165
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Prini P, Zamberletti E, Manenti C, Gabaglio M, Parolaro D, Rubino T. Neurobiological mechanisms underlying cannabis-induced memory impairment. Eur Neuropsychopharmacol 2020; 36:181-190. [PMID: 32139186 DOI: 10.1016/j.euroneuro.2020.02.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 01/27/2020] [Accepted: 02/17/2020] [Indexed: 01/23/2023]
Abstract
A growing body of literature suggests that cannabis intake can induce memory loss in humans and animals. Besides the recreational use, daily cannabis users may also belong to the ever-increasing population of patients who are administered cannabis as a medicine. As such, they also can experience impairments in memory as a negative side effect of their therapy. Comprehension of the neurobiological mechanisms responsible for such detrimental effects would be therefore of paramount relevance to public health. The investigation of neurobiological mechanisms in humans, despite the progress in the development of imaging technologies that allow the study of brain structure and function, still suffers substantial limitations. Animal models, instead, enable us to establish a causal relationship and thus to better elucidate the neurobiological mechanisms underlying the process under study. In this review, we will attempt to collect the insight coming from animal models about cannabis effects on memory, trying to depict a picture of the neurobiological mechanisms contributing to the development of cognitive deficits following cannabis use.
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Affiliation(s)
- Pamela Prini
- Department of Biotechnology and Life Sciences, and Neuroscience Center, University of Insubria, Busto Arsizio VA, Italy
| | - Erica Zamberletti
- Department of Biotechnology and Life Sciences, and Neuroscience Center, University of Insubria, Busto Arsizio VA, Italy
| | - Cristina Manenti
- Department of Biotechnology and Life Sciences, and Neuroscience Center, University of Insubria, Busto Arsizio VA, Italy
| | - Marina Gabaglio
- Department of Biotechnology and Life Sciences, and Neuroscience Center, University of Insubria, Busto Arsizio VA, Italy
| | - Daniela Parolaro
- Department of Biotechnology and Life Sciences, and Neuroscience Center, University of Insubria, Busto Arsizio VA, Italy; Zardi-Gori Foundation, Milan, Italy
| | - Tiziana Rubino
- Department of Biotechnology and Life Sciences, and Neuroscience Center, University of Insubria, Busto Arsizio VA, Italy.
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Tang XH, Zhang GF, Xu N, Duan GF, Jia M, Liu R, Zhou ZQ, Yang JJ. Extrasynaptic CaMKIIα is involved in the antidepressant effects of ketamine by downregulating GluN2B receptors in an LPS-induced depression model. J Neuroinflammation 2020; 17:181. [PMID: 32522211 PMCID: PMC7285526 DOI: 10.1186/s12974-020-01843-z] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 05/14/2020] [Indexed: 01/05/2023] Open
Abstract
Background A subanesthetic dose of ketamine provides rapid and effective antidepressant effects, but the molecular mechanism remains elusive. It has been reported that overactivation of extrasynaptic GluN2B receptors is associated with the antidepressant effects of ketamine and the interaction between GluN2B and calcium/calmodulin-dependent protein kinase IIα (CaMKIIα) is important for GluN2B localization and activity. Here, we tested whether changes of CaMKIIα and GluN2B are involved in the antidepressant effects of ketamine. Methods Lipopolysaccharide (LPS) was injected intraperitoneally (i.p.) into male C57BL/6 mice. For the interventional study, mice were administrated with ketamine (10 mg/kg, i.p.) or a CaMKIIα inhibitor KN93. Behavioral alterations were evaluated by open-field, novelty-suppressed feeding, and forced-swimming tests. Physiological functions were evaluated by the body weight and fur coat state of mice. The levels of p-CaMKIIα, CaMKIIα, p-GluN2B, GluN2B, p-CREB, CREB, BDNF, GluR1, and GluR2 in the hippocampus were detected by western blotting. The interaction between GluN2B and CaMKIIα was studied using immunoprecipitation assay and small interfering RNA (siRNA) assays. The colocalizations of GluN2B/PSD95 and p-GluN2B/PSD95 were detected by immunofluorescence. The long-term potentiation (LTP) in SC-CA1 of the hippocampus was detected by electrophysiology. Results LPS injection induced depression-like behaviors, which were accompanied by significant increases in extrasynaptic p-CaMKIIα expression, extrasynaptic GluN2B localization, and phosphorylation and decreases in p-CREB, BDNF, and GluR1 expressions and LTP impairment. These changes were prevented by ketamine administration. Immunoprecipitation assay revealed that LPS induced an increase in the p-CaMKIIα–GluN2B interaction, which was attenuated by ketamine administration. SiRNA assay revealed that CaMKIIα knockdown reduced the level and number of clusters of GluN2B in the cultured hippocampal neurons. KN93 administration also reduced extrasynaptic p-CaMKIIα expression, extrasynaptic GluN2B localization, and phosphorylation and exerted antidepressant effects. Conclusion These results indicate that extrasynaptic CaMKIIα plays a key role in the cellular mechanism of ketamine’s antidepressant effect and it is related to the downregulation of extrasynaptic GluN2B localization and phosphorylation.
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Affiliation(s)
- Xiao-Hui Tang
- Department of Anesthesiology, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu, China
| | - Guang-Fen Zhang
- Department of Anesthesiology, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu, China
| | - Ning Xu
- Department of Anesthesiology, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu, China
| | - Gui-Fang Duan
- Minister of Education Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing University, Nanjing, Jiangsu, China
| | - Min Jia
- Department of Anesthesiology, Jinling Hospital, School of Medicine, Nanjing University, Nanjing, Jiangsu, China
| | - Ru Liu
- Department of Anesthesiology, Jinling Hospital, School of Medicine, Nanjing University, Nanjing, Jiangsu, China
| | - Zhi-Qiang Zhou
- Department of Anesthesiology, Jinling Hospital, School of Medicine, Nanjing University, Nanjing, Jiangsu, China.
| | - Jian-Jun Yang
- Department of Anesthesiology, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu, China. .,Department of Anesthesiology, Pain and Perioperative Medicine, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China.
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167
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Rahmaninejad H, Pace T, Bhatt S, Sun B, Kekenes-Huskey P. Co-localization and confinement of ecto-nucleotidases modulate extracellular adenosine nucleotide distributions. PLoS Comput Biol 2020; 16:e1007903. [PMID: 32584811 PMCID: PMC7316229 DOI: 10.1371/journal.pcbi.1007903] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 04/22/2020] [Indexed: 12/30/2022] Open
Abstract
Nucleotides comprise small molecules that perform critical signaling roles in biological systems. Adenosine-based nucleotides, including adenosine tri-, di-, and mono-phosphate, are controlled through their rapid degradation by diphosphohydrolases and ecto-nucleotidases (NDAs). The interplay between nucleotide signaling and degradation is especially important in synapses formed between cells, which create signaling 'nanodomains'. Within these 'nanodomains', charged nucleotides interact with densely-packed membranes and biomolecules. While the contributions of electrostatic and steric interactions within such nanodomains are known to shape diffusion-limited reaction rates, less is understood about how these factors control the kinetics of nucleotidase activity. To quantify these factors, we utilized reaction-diffusion numerical simulations of 1) adenosine triphosphate (ATP) hydrolysis into adenosine monophosphate (AMP) and 2) AMP into adenosine (Ado) via two representative nucleotidases, CD39 and CD73. We evaluate these sequentially-coupled reactions in nanodomain geometries representative of extracellular synapses, within which we localize the nucleotidases. With this model, we find that 1) nucleotidase confinement reduces reaction rates relative to an open (bulk) system, 2) the rates of AMP and ADO formation are accelerated by restricting the diffusion of substrates away from the enzymes, and 3) nucleotidase co-localization and the presence of complementary (positive) charges to ATP enhance reaction rates, though the impact of these contributions on nucleotide pools depends on the degree to which the membrane competes for substrates. As a result, these contributions integratively control the relative concentrations and distributions of ATP and its metabolites within the junctional space. Altogether, our studies suggest that CD39 and CD73 nucleotidase activity within junctional spaces can exploit their confinement and favorable electrostatic interactions to finely control nucleotide signaling.
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Affiliation(s)
- Hadi Rahmaninejad
- Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky, United States of America
| | - Tom Pace
- Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky, United States of America
| | - Shashank Bhatt
- Paul Laurence Dunbar High School, Lexington, Kentucky, United States of America
| | - Bin Sun
- Department of Chemistry, University of Kentucky, Lexington, Kentucky, United States of America
| | - Peter Kekenes-Huskey
- Department of Cell & Molecular Physiology, Loyola University Chicago, Chicago, Illinois, United States of America
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168
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Esshili A, Manitz MP, Freund N, Juckel G. Induction of inducible nitric oxide synthase expression in activated microglia and astrocytes following pre- and postnatal immune challenge in an animal model of schizophrenia. Eur Neuropsychopharmacol 2020; 35:100-110. [PMID: 32439226 DOI: 10.1016/j.euroneuro.2020.04.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2019] [Revised: 02/24/2020] [Accepted: 04/09/2020] [Indexed: 12/15/2022]
Abstract
In the central nervous system, activated microglia and astrocytes produce proinflammatory mediators such as inducible nitric oxide (iNOS) and cytokines. Uncontrolled release of these mediators induced by immune challenge can lead to increased vulnerability to complex brain disorders such as schizophrenia. In this study, BALB/c mice were injected intraperitoneally (i.p) with the viral mimetic polyriboinosinic-polyribocytidilic acid (poly(I:C)) or saline. At postnatal day 30 (PND0), the animals were sacrificed and the hippocampus, corpus callosum, striatum, cortex, fimbria and ventricle were immunostained for Iba-1, a microglial marker, glial fibrillary acidic protein (GFAP), an astrocyte marker, and iNOS, an activation marker for NO. Additionally, serum cytokine profiling (Interleukin-2 (IL-2), IL- 4, IL-6, interferon gamma (IFN-γ), tumour necrosis factor (TNF), IL-17A and IL-10) was determined using serum samples from poly(I:C)-treated and control mice. Our results demonstrated that poly(I:C) induced overactivation of differential proinflammatory responses in microglia and astrocytes, which could be strongly enhanced by a postnatal poly(I:C) administration before PND 30 in one part of the animals investigated. Specifically, there was significant iNOS upregulation in hippocampus, cortex and corpus callosum of poly(I:C)-affected off-springs. These inflammatory alterations were accompanied by increased circulating levels of the proinflammatory cytokines tumour necrosis factor alpha (TNF-α) and interleukin-6 (IL-6). This study provides insight into the role of microglia and astrocytes in an animal model of schizophrenia and an understanding of the regulation of iNOS expression in glial cells and cytokine networks. This knowledge could help identify novel targets for anti-oxidative and anti-inflammatory therapeutic schizophrenia intervention.
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Affiliation(s)
- Awatef Esshili
- Laboratory of Psychoneuroimmunology, Department of Psychiatry, LWL-University Hospital, Ruhr University Bochum, Bochum, Germany; Laboratoire de génétique, biodiversité et valorisation des bioressources, Institut supérieur de biotechnologie de Monastir, Université de Monastir, Tunisie
| | - Marie-Pierre Manitz
- Laboratory of Psychoneuroimmunology, Department of Psychiatry, LWL-University Hospital, Ruhr University Bochum, Bochum, Germany
| | - Nadja Freund
- Laboratory of Psychoneuroimmunology, Department of Psychiatry, LWL-University Hospital, Ruhr University Bochum, Bochum, Germany
| | - Georg Juckel
- Laboratory of Psychoneuroimmunology, Department of Psychiatry, LWL-University Hospital, Ruhr University Bochum, Bochum, Germany.
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169
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Ward H, West SJ. Microglia: sculptors of neuropathic pain? ROYAL SOCIETY OPEN SCIENCE 2020; 7:200260. [PMID: 32742693 PMCID: PMC7353970 DOI: 10.1098/rsos.200260] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 06/01/2020] [Indexed: 05/02/2023]
Abstract
Neuropathic pain presents a huge societal and individual burden. The limited efficacy of current analgesics, diagnostic markers and clinical trial outcome measures arises from an incomplete understanding of the underlying mechanisms. A large and growing body of evidence has established the important role of microglia in the onset and possible maintenance of neuropathic pain, and these cells may represent an important target for future therapy. Microglial research has further revealed their important role in structural remodelling of the nervous system. In this review, we aim to explore the evidence for microglia in sculpting nervous system structure and function, as well as their important role in neuropathic pain, and finally integrate these studies to synthesize a new model for microglia in somatosensory circuit remodelling, composed of six key and inter-related mechanisms. Summarizing the mechanisms through which microglia modulate nervous system structure and function helps to frame a better understanding of neuropathic pain, and provide a clear roadmap for future research.
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Affiliation(s)
- Harry Ward
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Steven J. West
- Sainsbury Wellcome Centre, University College London, 25 Howland St, London WC1E 6BT, UK
- Author for correspondence: Steven J. West e-mail:
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Boggess T, Risher WC. Clinical and basic research investigations into the long-term effects of prenatal opioid exposure on brain development. J Neurosci Res 2020; 100:396-409. [PMID: 32459039 DOI: 10.1002/jnr.24642] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 04/01/2020] [Accepted: 04/27/2020] [Indexed: 12/26/2022]
Abstract
Coincident with the opioid epidemic in the United States has been a dramatic increase in the number of children born with neonatal abstinence syndrome (NAS), a form of withdrawal resulting from opioid exposure during pregnancy. Many research efforts on NAS have focused on short-term care, including acute symptom treatment and weaning of the infants off their drug dependency prior to authorizing their release. However, investigations into the long-term effects of prenatal opioid exposure (POE) on brain development, from the cellular to the behavioral level, have not been as frequent. Given the importance of the perinatal period for human brain development, opioid-induced disturbances in the formation and function of nascent synaptic networks and glia have the potential to impact brain connectivity and cognition long after the drug supply is cutoff shortly after birth. In this review, we will summarize the current state of NAS research, bringing together findings from human studies and preclinical animal models to highlight what is known about how POE can induce significant, prolonged deficits in brain structure and function. With rates of NAS continuing to rise, particularly in regions that already face substantial socioeconomic challenges, we speculate as to the most promising avenues for future research to alleviate this growing multigenerational threat.
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Affiliation(s)
- Taylor Boggess
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine at Marshall University, Huntington, WV, USA
| | - W Christopher Risher
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine at Marshall University, Huntington, WV, USA
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171
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Gupta N, Jadhav S, Tan KL, Saw G, Mallilankaraman KB, Dheen ST. miR-142-3p Regulates BDNF Expression in Activated Rodent Microglia Through Its Target CAMK2A. Front Cell Neurosci 2020; 14:132. [PMID: 32508597 PMCID: PMC7253665 DOI: 10.3389/fncel.2020.00132] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 04/20/2020] [Indexed: 12/31/2022] Open
Abstract
Microglia, the innate immune effector cells of the mammalian central nervous system (CNS), are involved in the development, homeostasis, and pathology of CNS. Microglia become activated in response to various insults and injuries and protect the CNS by phagocytosing the invading pathogens, dead neurons, and other cellular debris. Recent studies have demonstrated that the epigenetic mechanisms ensure the coordinated regulation of genes involved in microglial activation. In this study, we performed a microRNA (miRNA) microarray in activated primary microglia derived from rat pup's brain and identified differentially expressed miRNAs targeting key genes involved in cell survival, apoptosis, and inflammatory responses. Interestingly, miR-142-3p, one of the highly up-regulated miRNAs in microglia upon lipopolysaccharide (LPS)-mediated activation, compared to untreated primary microglia cells was predicted to target Ca2+/calmodulin dependent kinase 2a (CAMK2A). Further, luciferase reporter assay confirmed that miR-142-3p targets the 3'UTR of Camk2a. CAMK2A has been implicated in regulating the expression of brain-derived neurotrophic factor (BDNF) and long-term potentiation (LTP), a cellular mechanism underlying memory and learning. Given this, this study further focused on understanding the miR-142-3p mediated regulation of the CAMK2A-BDNF pathway via Cyclic AMP-responsive element-binding protein (CREB) in activated microglia. The results revealed that CAMK2A was downregulated in activated microglia, suggesting an inverse relationship between miR-142-3p and Camk2a in activated microglia. Overexpression of miR-142-3p in microglia was found to decrease the expression of CAMK2A and subsequently BDNF through regulation of CREB phosphorylation. Functional analysis through shRNA-mediated stable knockdown of CAMK2A in microglia confirmed that the regulation of BDNF by miR-142-3p is via CAMK2A. Overall, this study provides a database of differentially expressed miRNAs in activated primary microglia and reveals that microglial miR-142-3p regulates the CAMK2A-CREB-BDNF pathway which is involved in synaptic plasticity.
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Affiliation(s)
- Neelima Gupta
- Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Shweta Jadhav
- Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Kai-Leng Tan
- Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Genevieve Saw
- Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Karthik Babu Mallilankaraman
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - S Thameem Dheen
- Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
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Aging with Toxoplasma gondii results in pathogen clearance, resolution of inflammation, and minimal consequences to learning and memory. Sci Rep 2020; 10:7979. [PMID: 32409672 PMCID: PMC7224383 DOI: 10.1038/s41598-020-64823-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 04/15/2020] [Indexed: 12/31/2022] Open
Abstract
Persistent inflammation has been identified as a contributor to aging-related neurodegenerative disorders such as Alzheimer's disease. Normal aging, in the absence of dementia, also results in gradual cognitive decline and is thought to arise, in part, because of a chronic pro-inflammatory state in the brain. Toxoplasma gondii is an obligate intracellular parasite that establishes a persistent, asymptomatic infection of the central nervous system (CNS) accompanied by a pro-inflammatory immune response in many of its hosts, including humans and rodents. Several studies have suggested that the inflammation generated by certain strains of T. gondii infection can be neuroprotective in the context of a secondary insult like beta-amyloid accumulation or stroke. Given these neuroprotective studies, we hypothesized that a prolonged infection with T. gondii may protect against age-associated decline in cognition. To test this hypothesis, we infected young adult mice with either of two genetically distinct, persistent T. gondii strains (Prugniaud/type II/haplogroup 2 and CEP/type III/haplogroup 3) and monitored mouse weight, survival, and learning and memory over the ensuing 20 months. At the end of the study, we evaluated CNS inflammation and parasite burden in the surviving mice. We found that parasite infection had no impact on age-associated decline in learning and memory and that by 20 months post infection, in the surviving mice, we found no evidence of parasite DNA, cysts, or inflammation in the CNS. In addition, we found that mice infected with type III parasites, which are supposed to be less virulent than the type II parasites, had a lower rate of long-term survival. Collectively, these data indicate that T. gondii may not cause a life-long CNS infection. Rather, parasites are likely slowly cleared from the CNS and infection and parasite clearance neither positively nor negatively impacts learning and memory in aging.
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Lee J, Ha S, Lee ST, Park SG, Shin S, Choi JR, Cheon KA. Next-Generation Sequencing in Korean Children With Autism Spectrum Disorder and Comorbid Epilepsy. Front Pharmacol 2020; 11:585. [PMID: 32477112 PMCID: PMC7240034 DOI: 10.3389/fphar.2020.00585] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 04/16/2020] [Indexed: 12/23/2022] Open
Abstract
Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impairments in social communication and restricted and repetitive behaviors and interests. Identifying the genetic background may be one of the key features for the future diagnosis and treatment of ASD. With the tremendous development in genetic diagnosis techniques, next-generation sequencing (NGS) can be used to analyze multiple genes simultaneously with a single test in laboratory and clinical settings and is well suited for investigating autism genetics. According to previous studies, there are two types of genetic variants in ASD, rare variants and common variants, and both are important in explaining pathogenesis. In this study, NGS data from 137 participants with ASD were reviewed retrospectively with consideration for comorbid epilepsy. Diagnostic yield was 17.51% (24/137), and pathogenic/likely pathogenic variants were seen more frequently in female participants. Fourteen participants were diagnosed with comorbid epilepsy, six of them had pathogenic/likely pathogenic variants (43%). Genes with variants of unknown significance (VOUS) which have one or more evidence of pathogenicity following the American College of Medical Genetics (ACMG) criteria were also reviewed in both ASD and ASD with comorbid epilepsy groups. We found that most frequently found VOUS genes have previously been reported as genes related to ASD or other developmental disorders. These results suggest that when interpreting the NGS results in the clinical setting, careful observation of VOUS with some pathological evidence might contribute to the discovery of genetic pathogenesis of neurodevelopmental disorders such as ASD and epilepsy.
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Affiliation(s)
- Junghan Lee
- Division of Child and Adolescent Psychiatry, Department of Psychiatry, Severance Hospital, Institute of Behavioral Science in Medicine, Yonsei University College of Medicine, Seoul, South Korea
| | - Sungji Ha
- Department of Psychiatry, Institute of Behavioral Science in Medicine, Yonsei University College of Medicine, Seoul, South Korea
| | - Seung-Tae Lee
- Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, South Korea
| | - Sung-Gyun Park
- Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, South Korea
| | - Saeam Shin
- Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, South Korea
| | - Jong Rak Choi
- Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, South Korea
| | - Keun-Ah Cheon
- Division of Child and Adolescent Psychiatry, Department of Psychiatry, Severance Hospital, Institute of Behavioral Science in Medicine, Yonsei University College of Medicine, Seoul, South Korea
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174
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Mondelli V, Vernon AC. From early adversities to immune activation in psychiatric disorders: the role of the sympathetic nervous system. Clin Exp Immunol 2020; 197:319-328. [PMID: 31319436 DOI: 10.1111/cei.13351] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/14/2019] [Indexed: 02/07/2023] Open
Abstract
Increased peripheral levels of cytokines and central microglial activation have been reported in patients with psychiatric disorders. The degree of both innate and adaptive immune activation is also associated with worse clinical outcomes and poor treatment response in these patients. Understanding the possible causes and mechanisms leading to this immune activation is therefore an important and necessary step for the development of novel and more effective treatment strategies for these patients. In this work, we review the evidence of literature pointing to childhood trauma as one of the main causes behind the increased immune activation in patients with psychiatric disorders. We then discuss the potential mechanisms linking the experience of early life adversity (ELA) to innate immune activation. Specifically, we focus on the innervation of the bone marrow from sympathetic nervous system (SNS) as a new and emerging mechanism that has the potential to bridge the observed increases in both central and peripheral inflammatory markers in patients exposed to ELA. Experimental studies in laboratory rodents suggest that SNS activation following early life stress exposure causes a shift in the profile of innate immune cells, with an increase in proinflammatory monocytes. In turn, these cells traffic to the brain and influence neural circuitry, which manifests as increased anxiety and other relevant behavioural phenotypes. To date, however, very few studies have been conducted to explore this candidate mechanism in humans. Future research is also needed to clarify whether these pathways could be partially reversible to improve prevention and treatment strategies in the future.
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Affiliation(s)
- V Mondelli
- King's College London, Institute of Psychiatry Psychology and Neuroscience, Department of Psychological Medicine, London, UK.,NIHR Biomedical Research Centre South London and Maudsley NHS Trust, London, UK
| | - A C Vernon
- King's College London, Institute of Psychiatry Psychology and Neuroscience, Department of Basic and Clinical Neuroscience, London, UK.,MRC Centre for Neurodevelopmental Disorders, King's College London, London, UK
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175
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Kudryashova I, Stepanichev M, Manolova A, Gulyaeva N. Deficit of Long-Term Potentiation Induction, but Not Maintenance, in the Juvenile Hippocampus after Neonatal Proinflammatory Stress. Dev Neurosci 2020; 41:318-326. [PMID: 32369803 DOI: 10.1159/000507347] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 03/19/2020] [Indexed: 11/19/2022] Open
Abstract
CA3-CA1 long-term potentiation (LTP) in the hippocampal slices from juvenile Wistar rats was studied to reveal factors potentially contributing to different sensitivity to neonatal proinflammatory stress (NPS). NPS was induced by intra-peritoneal injections of bacterial lipopolysaccharide (LPS) to neonatal rats (two injections of LPS, or saline in the control group, consecutively on postnatal days 3 and 5 [PND3 and PND5]). In females, a significant effect of NPS on hippocampus development was associated with modifications of long-term synaptic plasticity, the synapses becoming more resistant to LTP induction. LTP deficit in the slices of the NPS group was not associated with a decrease in LTP maintenance, since late LTP generally corresponded to early LTP magnitude, similar in all groups. Moreover, partial correlation revealed significantly higher residual LTP 1 h after high-frequency stimulation in the NPS groups compared to the corresponding value of early LTP in the control groups, suggesting improved consolidation. Both effects were evident in NPS females. A number of males responded to NPS similarly to females, while others were relatively resistant to NPS exposure, a significant increase in variability of LTP magnitude being revealed in NPS males compared to respective females and the control groups. We suggest that postnatal development of long-term plasticity after NPS is similar in animals of both sexes; however, additional specific factor(s) may promote a relative resistance of the male brain.
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Affiliation(s)
- Irina Kudryashova
- Laboratory of Functional Biochemistry of the Nervous System, Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, Russian Federation
| | - Mikhail Stepanichev
- Laboratory of Functional Biochemistry of the Nervous System, Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, Russian Federation,
| | - Anna Manolova
- Laboratory of Functional Biochemistry of the Nervous System, Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, Russian Federation
| | - Natalia Gulyaeva
- Laboratory of Functional Biochemistry of the Nervous System, Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, Russian Federation
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176
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Regulation of Microglial Functions by Purinergic Mechanisms in the Healthy and Diseased CNS. Cells 2020; 9:cells9051108. [PMID: 32365642 PMCID: PMC7290360 DOI: 10.3390/cells9051108] [Citation(s) in RCA: 112] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 04/25/2020] [Accepted: 04/27/2020] [Indexed: 02/07/2023] Open
Abstract
Microglial cells, the resident macrophages of the central nervous system (CNS), exist in a process-bearing, ramified/surveying phenotype under resting conditions. Upon activation by cell-damaging factors, they get transformed into an amoeboid phenotype releasing various cell products including pro-inflammatory cytokines, chemokines, proteases, reactive oxygen/nitrogen species, and the excytotoxic ATP and glutamate. In addition, they engulf pathogenic bacteria or cell debris and phagocytose them. However, already resting/surveying microglia have a number of important physiological functions in the CNS; for example, they shield small disruptions of the blood–brain barrier by their processes, dynamically interact with synaptic structures, and clear surplus synapses during development. In neurodegenerative illnesses, they aggravate the original disease by a microglia-based compulsory neuroinflammatory reaction. Therefore, the blockade of this reaction improves the outcome of Alzheimer’s Disease, Parkinson’s Disease, multiple sclerosis, amyotrophic lateral sclerosis, etc. The function of microglia is regulated by a whole array of purinergic receptors classified as P2Y12, P2Y6, P2Y4, P2X4, P2X7, A2A, and A3, as targets of endogenous ATP, ADP, or adenosine. ATP is sequentially degraded by the ecto-nucleotidases and 5′-nucleotidase enzymes to the almost inactive inosine as an end product. The appropriate selective agonists/antagonists for purinergic receptors as well as the respective enzyme inhibitors may profoundly interfere with microglial functions and reconstitute the homeostasis of the CNS disturbed by neuroinflammation.
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177
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Haddad FL, Patel SV, Schmid S. Maternal Immune Activation by Poly I:C as a preclinical Model for Neurodevelopmental Disorders: A focus on Autism and Schizophrenia. Neurosci Biobehav Rev 2020; 113:546-567. [PMID: 32320814 DOI: 10.1016/j.neubiorev.2020.04.012] [Citation(s) in RCA: 107] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Revised: 01/28/2020] [Accepted: 04/09/2020] [Indexed: 12/18/2022]
Abstract
Maternal immune activation (MIA) in response to a viral infection during early and mid-gestation has been linked through various epidemiological studies to a higher risk for the child to develop autism or schizophrenia-related symptoms.. This has led to the establishment of the pathogen-free poly I:C-induced MIA animal model for neurodevelopmental disorders, which shows relatively high construct and face validity. Depending on the experimental variables, particularly the timing of poly I:C administration, different behavioural and molecular phenotypes have been described that relate to specific symptoms of neurodevelopmental disorders such as autism spectrum disorder and/or schizophrenia. We here review and summarize epidemiological evidence for the effects of maternal infection and immune activation, as well as major findings in different poly I:C MIA models with a focus on poly I:C exposure timing, behavioural and molecular changes in the offspring, and characteristics of the model that relate it to autism spectrum disorder and schizophrenia.
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Affiliation(s)
- Faraj L Haddad
- Anatomy & Cell Biology, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, ON, Canada.
| | - Salonee V Patel
- Anatomy & Cell Biology, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, ON, Canada.
| | - Susanne Schmid
- Anatomy & Cell Biology, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, ON, Canada.
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178
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Li D, Chen M, Meng T, Fei J. Hippocampal microglial activation triggers a neurotoxic-specific astrocyte response and mediates etomidate-induced long-term synaptic inhibition. J Neuroinflammation 2020; 17:109. [PMID: 32264970 PMCID: PMC7140340 DOI: 10.1186/s12974-020-01799-0] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 03/31/2020] [Indexed: 01/06/2023] Open
Abstract
Background Accumulating evidence has highlighted the importance of microglial and astrocyte responses in the pathological development of postoperative cognitive dysfunction (POCD). However, the mechanisms involved are not well understood. Methods A perioperative neurocognitive disorders (PND) mouse model was generated by administering etomidate, and cognitive function was assessed using the Morris water maze and novel object recognition tests. Excitatory and inhibitory postsynaptic currents were recorded to analyze neuronal activity. In addition, microglia and astrocytes were isolated by magnetic-activated cell sorting, and genes that were activated in these cells were identified using quantitative polymerase chain reaction. Results We observed dramatic cognitive impairment at 1 and 3 weeks after etomidate was administered to 18 month-old mice. Microglia and astrocytes isolated from the hippocampus showed significant microglial activation during the early pathological stage (i.e., 1 week after etomidate injection) and an A1-specific astrocyte response during the late pathological stage (i.e., 3 weeks after etomidate injection). Furthermore, when microglia were eliminated before etomidate was injected, the A1-specific astrocyte activation response was significantly reduced, and cognitive function improved. However, when microglia were eliminated after etomidate application, astrocyte activation and cognitive function were not significantly altered. In addition, activating microglia immediately after a sedative dose of etomidate was injected markedly increased A1-specific astrocyte activation and cognitive dysfunction. Conclusions A1-specific astrocyte activation is triggered by activated microglia during the initial pathological stage of PND and induces long-term synaptic inhibition and cognitive deficiencies. These results improve our understanding of how PND develops and may suggest therapeutic targets.
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Affiliation(s)
- Dongliang Li
- Department of Anesthesiology, Qilu Hospital of Shandong University, Ji'nan, 250012, China
| | - Mingming Chen
- Jiangsu Key Laboratory of Drug Screening, China Pharmaceutical University, Nanjing, 210009, China
| | - Tao Meng
- Department of Anesthesiology, Qilu Hospital of Shandong University, Ji'nan, 250012, China
| | - Jianchun Fei
- Department of Anesthesiology, Qilu Hospital of Shandong University, Ji'nan, 250012, China.
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179
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Hampel H, Caraci F, Cuello AC, Caruso G, Nisticò R, Corbo M, Baldacci F, Toschi N, Garaci F, Chiesa PA, Verdooner SR, Akman-Anderson L, Hernández F, Ávila J, Emanuele E, Valenzuela PL, Lucía A, Watling M, Imbimbo BP, Vergallo A, Lista S. A Path Toward Precision Medicine for Neuroinflammatory Mechanisms in Alzheimer's Disease. Front Immunol 2020; 11:456. [PMID: 32296418 PMCID: PMC7137904 DOI: 10.3389/fimmu.2020.00456] [Citation(s) in RCA: 189] [Impact Index Per Article: 47.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2019] [Accepted: 02/27/2020] [Indexed: 12/13/2022] Open
Abstract
Neuroinflammation commences decades before Alzheimer's disease (AD) clinical onset and represents one of the earliest pathomechanistic alterations throughout the AD continuum. Large-scale genome-wide association studies point out several genetic variants—TREM2, CD33, PILRA, CR1, MS4A, CLU, ABCA7, EPHA1, and HLA-DRB5-HLA-DRB1—potentially linked to neuroinflammation. Most of these genes are involved in proinflammatory intracellular signaling, cytokines/interleukins/cell turnover, synaptic activity, lipid metabolism, and vesicle trafficking. Proteomic studies indicate that a plethora of interconnected aberrant molecular pathways, set off and perpetuated by TNF-α, TGF-β, IL-1β, and the receptor protein TREM2, are involved in neuroinflammation. Microglia and astrocytes are key cellular drivers and regulators of neuroinflammation. Under physiological conditions, they are important for neurotransmission and synaptic homeostasis. In AD, there is a turning point throughout its pathophysiological evolution where glial cells sustain an overexpressed inflammatory response that synergizes with amyloid-β and tau accumulation, and drives synaptotoxicity and neurodegeneration in a self-reinforcing manner. Despite a strong therapeutic rationale, previous clinical trials investigating compounds with anti-inflammatory properties, including non-steroidal anti-inflammatory drugs (NSAIDs), did not achieve primary efficacy endpoints. It is conceivable that study design issues, including the lack of diagnostic accuracy and biomarkers for target population identification and proof of mechanism, may partially explain the negative outcomes. However, a recent meta-analysis indicates a potential biological effect of NSAIDs. In this regard, candidate fluid biomarkers of neuroinflammation are under analytical/clinical validation, i.e., TREM2, IL-1β, MCP-1, IL-6, TNF-α receptor complexes, TGF-β, and YKL-40. PET radio-ligands are investigated to accomplish in vivo and longitudinal regional exploration of neuroinflammation. Biomarkers tracking different molecular pathways (body fluid matrixes) along with brain neuroinflammatory endophenotypes (neuroimaging markers), can untangle temporal–spatial dynamics between neuroinflammation and other AD pathophysiological mechanisms. Robust biomarker–drug codevelopment pipelines are expected to enrich large-scale clinical trials testing new-generation compounds active, directly or indirectly, on neuroinflammatory targets and displaying putative disease-modifying effects: novel NSAIDs, AL002 (anti-TREM2 antibody), anti-Aβ protofibrils (BAN2401), and AL003 (anti-CD33 antibody). As a next step, taking advantage of breakthrough and multimodal techniques coupled with a systems biology approach is the path to pursue for developing individualized therapeutic strategies targeting neuroinflammation under the framework of precision medicine.
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Affiliation(s)
- Harald Hampel
- Sorbonne University, GRC no. 21, Alzheimer Precision Medicine (APM), AP-HP, Pitié-Salpêtrière Hospital, Boulevard de l'hôpital, Paris, France
| | - Filippo Caraci
- Department of Drug Sciences, University of Catania, Catania, Italy.,Oasi Research Institute-IRCCS, Troina, Italy
| | - A Claudio Cuello
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada.,Department of Anatomy and Cell Biology, McGill University, Montreal, QC, Canada.,Department of Pharmacology and Therapeutics, McGill University, Montreal, QC, Canada.,Department of Pharmacology, University of Oxford, Oxford, United Kingdom
| | | | - Robert Nisticò
- Laboratory of Neuropharmacology, EBRI Rita Levi-Montalcini Foundation, Rome, Italy.,School of Pharmacy, Department of Biology, University of Rome Tor Vergata, Rome, Italy
| | - Massimo Corbo
- Department of Neurorehabilitation Sciences, Casa Cura Policlinico, Milan, Italy
| | - Filippo Baldacci
- Sorbonne University, GRC no. 21, Alzheimer Precision Medicine (APM), AP-HP, Pitié-Salpêtrière Hospital, Boulevard de l'hôpital, Paris, France.,Brain & Spine Institute (ICM), INSERM U 1127, CNRS UMR 7225, Boulevard de l'hôpital, Paris, France.,Institute of Memory and Alzheimer's Disease (IM2A), Department of Neurology, Pitié-Salpêtrière Hospital, AP-HP, Paris, France.,Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Nicola Toschi
- Department of Biomedicine and Prevention, University of Rome "Tor Vergata", Rome, Italy.,Department of Radiology, "Athinoula A. Martinos" Center for Biomedical Imaging, Boston, MA, United States.,Harvard Medical School, Boston, MA, United States
| | - Francesco Garaci
- Department of Biomedicine and Prevention, University of Rome "Tor Vergata", Rome, Italy.,Casa di Cura "San Raffaele Cassino", Cassino, Italy
| | - Patrizia A Chiesa
- Sorbonne University, GRC no. 21, Alzheimer Precision Medicine (APM), AP-HP, Pitié-Salpêtrière Hospital, Boulevard de l'hôpital, Paris, France.,Brain & Spine Institute (ICM), INSERM U 1127, CNRS UMR 7225, Boulevard de l'hôpital, Paris, France.,Institute of Memory and Alzheimer's Disease (IM2A), Department of Neurology, Pitié-Salpêtrière Hospital, AP-HP, Paris, France
| | | | | | - Félix Hernández
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Madrid, Spain.,Network Center for Biomedical Research in Neurodegenerative Diseases (CIBERNED), Madrid, Spain
| | - Jesús Ávila
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Madrid, Spain.,Network Center for Biomedical Research in Neurodegenerative Diseases (CIBERNED), Madrid, Spain
| | | | | | - Alejandro Lucía
- Faculty of Sport Sciences, Universidad Europea de Madrid, Madrid, Spain.,Research Institute of the Hospital 12 de Octubre ("imas"), Madrid, Spain.,Centro de Investigación Biomédica en Red Fragilidad y Envejecimiento Saludable (CIBERFES), Madrid, Spain
| | | | - Bruno P Imbimbo
- Research & Development Department, Chiesi Farmaceutici, Parma, Italy
| | - Andrea Vergallo
- Sorbonne University, GRC no. 21, Alzheimer Precision Medicine (APM), AP-HP, Pitié-Salpêtrière Hospital, Boulevard de l'hôpital, Paris, France
| | - Simone Lista
- Sorbonne University, GRC no. 21, Alzheimer Precision Medicine (APM), AP-HP, Pitié-Salpêtrière Hospital, Boulevard de l'hôpital, Paris, France.,Brain & Spine Institute (ICM), INSERM U 1127, CNRS UMR 7225, Boulevard de l'hôpital, Paris, France.,Institute of Memory and Alzheimer's Disease (IM2A), Department of Neurology, Pitié-Salpêtrière Hospital, AP-HP, Paris, France
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180
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Kuter KZ, Cenci MA, Carta AR. The role of glia in Parkinson's disease: Emerging concepts and therapeutic applications. PROGRESS IN BRAIN RESEARCH 2020; 252:131-168. [PMID: 32247363 DOI: 10.1016/bs.pbr.2020.02.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Originally believed to primarily affect neurons, Parkinson's disease (PD) has recently been recognized to also affect the functions and integrity of microglia and astroglia, two cell categories of fundamental importance to brain tissue homeostasis, defense, and repair. Both a loss of glial supportive-defensive functions and a toxic gain of glial functions are implicated in the neurodegenerative process. Moreover, the chronic treatment with L-DOPA may cause maladaptive glial plasticity favoring a development of therapy complications. This chapter focuses on the pathophysiology of PD from a glial point of view, presenting this rapidly growing field from the first discoveries made to the most recent developments. We report and compare histopathological and molecular findings from experimental models of PD and human studies. We moreover discuss the important role played by astrocytes in compensatory adaptations taking place during presymptomatic disease stages. We finally describe examples of potential therapeutic applications stemming from an increased understanding of the important roles of glia in PD.
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Affiliation(s)
- Katarzyna Z Kuter
- Department of Neuropsychopharmacology, Maj Institute of Pharmacology, Polish Academy of Sciences, Krakow, Poland.
| | - M Angela Cenci
- Basal Ganglia Pathophysiology Unit, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Anna R Carta
- Department of Biomedical Sciences, University of Cagliari, Cittadella Universitaria di Monserrato, Cagliari, Italy.
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181
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Liu J, Tang M, Harkin K, Du X, Luo C, Chen M, Xu H. Single-cell RNA sequencing study of retinal immune regulators identified CD47 and CD59a expression in photoreceptors-Implications in subretinal immune regulation. J Neurosci Res 2020; 98:1498-1513. [PMID: 32166783 DOI: 10.1002/jnr.24618] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 02/21/2020] [Accepted: 02/29/2020] [Indexed: 12/29/2022]
Abstract
The neuroretina is protected by its own defense system, that is microglia and the complement system. Under normal physiological conditions, microglial activation is tightly regulated by the neurons although the underlying mechanism remains elusive. Using published single-cell RNA sequencing data sets, we found that immune regulatory molecules including CD200, CD47, CX3CL1, TGFβ, and complement inhibitor CD59a are expressed by various retinal neurons. Importantly, we found that photoreceptors express higher levels of CD47 and CD59a, which was further confirmed in cultured 661W cells, WERI-Rb1 cells, and microdissected photoreceptors from human eyes. The expression of CD59a mRNA in 661W cells was upregulated by TNFα and hypoxia, whereas LPS, hypoxia, and IL-4 upregulated CD47 mRNA expression in 661W cells. Immunofluorescence staining detected strong CD59a immunoreactivity in the outer nuclear layer, inner/outer segments, and discrete staining in ganglion cell layer (GCL), inner plexiform layer (IPL), and outer plexiform layer. The expression of CD59a in photoreceptors was increased in the detached retina, but decreased in retinas from experimental autoimmune uveoretinitis (EAU) mice. In EAU retina, CD59a was highly expressed by active immune cells. CD47 was detected in GCL, IPL, and inner nuclear layer and some photoreceptors. The expression of CD47 in photoreceptors was also increased in the detached retina but decreased in EAU retina. In a coculture system, 661W enhanced arginase-1 and reduced IL-6 mRNA expression in BV2 microglial cells. Our results suggest that photoreceptors express immune regulatory molecules and may have the potential to regulate immune activation in the outer retina/subretinal space under pathophysiological conditions.
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Affiliation(s)
- Jian Liu
- Aier Eye Institute, Aier School of Ophthalmology, Central South University, Changsha, P.R. China
| | - Miao Tang
- The Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, Belfast, UK
| | - Kevin Harkin
- The Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, Belfast, UK
| | - Xuan Du
- The Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, Belfast, UK
| | - Chang Luo
- Aier Eye Institute, Aier School of Ophthalmology, Central South University, Changsha, P.R. China
| | - Mei Chen
- The Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, Belfast, UK
| | - Heping Xu
- Aier Eye Institute, Aier School of Ophthalmology, Central South University, Changsha, P.R. China.,The Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, Belfast, UK
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182
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Stowell RD, Majewska AK. Acute ethanol exposure rapidly alters cerebellar and cortical microglial physiology. Eur J Neurosci 2020; 54:5834-5843. [PMID: 32064695 DOI: 10.1111/ejn.14706] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 01/20/2020] [Accepted: 02/09/2020] [Indexed: 12/13/2022]
Abstract
Alcohol use is highly prevalent in modern society and ramifications of alcohol abuse pose a large public health concern. Previous work investigating the effects of alcohol exposure on the brain has implicated microglia, the resident immune cells of the central nervous system (CNS), as critical participants in the brain's response to chronic and developmental ethanol (EtOH) exposure. As rapid sensors of their environment, microglia also have the capacity to rapidly respond to alcohol administration and to contribute to acute effects of alcohol on the brain; however, their acute responses have not been assessed. Here, for the first time, we have examined the acute response of microglia to alcohol intoxication in vivo utilizing two-photon microscopy to assess the dynamics of these motile cells in both visual cortex and the cerebellum of mice. We found that microglia respond rapidly to EtOH exposure with fast changes in morphology, motility, parenchyma surveillance, and injury response. However, regional differences between the responses of cerebellar and cortical microglial populations indicate that subtle differences in microglial physiology may alter their vulnerability to acute alcohol intoxication. Our findings suggest that the longer-term effects of repeated EtOH exposure on microglia may result from repeat acute alterations in microglial physiology by single exposure to alcohol which rapidly alter behavior in specific microglial populations.
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Affiliation(s)
- Rianne D Stowell
- Department of Neuroscience, Del Monte Institute for Neuroscience, University of Rochester Medical Center, Rochester, NY, USA.,Neuroscience Graduate Program, University of Rochester Medical Center, Rochester, NY, USA
| | - Ania K Majewska
- Department of Neuroscience, Del Monte Institute for Neuroscience, University of Rochester Medical Center, Rochester, NY, USA.,Center for Visual Science, University of Rochester Medical Center, Rochester, NY, USA
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183
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Li LZ, Huang YY, Yang ZH, Zhang SJ, Han ZP, Luo YM. Potential microglia-based interventions for stroke. CNS Neurosci Ther 2020; 26:288-296. [PMID: 32064759 PMCID: PMC7052807 DOI: 10.1111/cns.13291] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 12/10/2019] [Accepted: 01/16/2020] [Indexed: 12/17/2022] Open
Abstract
A large number of families worldwide suffer from the physical and mental burden posed by stroke. An increasing number of studies aimed at the prevention and treatment of stroke have been conducted. Specifically, manipulating the immune response to stroke is under intense investigation. Microglia are the principal immune cells in the brain and are the first line of defense against the pathophysiology induced by stroke. Increasing evidence has suggested that microglia play diverse roles that depend on dynamic interactions with neurons, astrocytes, and other neighboring cells both in the normal brain and under pathological conditions, including stroke. Moreover, there are dynamic alterations in microglial functions with respect to aging and sex differences in the human brain, which offer a deep understanding of the conditions of stroke patients of different ages and sex. Hence, we review the dynamic microglial reactions caused by aging, sex, and crosstalk with neighboring cells both in normal conditions and after stroke and relevant potential interventions.
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Affiliation(s)
- Ling-Zhi Li
- Institute of Cerebrovascular Disease Research and Department of Neurology, Xuanwu Hospital of Capital Medical University, Beijing, China
| | - Yu-You Huang
- Institute of Cerebrovascular Disease Research and Department of Neurology, Xuanwu Hospital of Capital Medical University, Beijing, China
| | - Zhen-Hong Yang
- Institute of Cerebrovascular Disease Research and Department of Neurology, Xuanwu Hospital of Capital Medical University, Beijing, China
| | - Si-Jia Zhang
- Institute of Cerebrovascular Disease Research and Department of Neurology, Xuanwu Hospital of Capital Medical University, Beijing, China
| | - Zi-Ping Han
- Institute of Cerebrovascular Disease Research and Department of Neurology, Xuanwu Hospital of Capital Medical University, Beijing, China.,Beijing Geriatric Medical Research Center and Beijing Key Laboratory of Translational Medicine for Cerebrovascular Diseases, Beijing, China
| | - Yu-Min Luo
- Institute of Cerebrovascular Disease Research and Department of Neurology, Xuanwu Hospital of Capital Medical University, Beijing, China.,Beijing Geriatric Medical Research Center and Beijing Key Laboratory of Translational Medicine for Cerebrovascular Diseases, Beijing, China.,Beijing Institute for Brain Disorders, Beijing, China
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184
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Illes P, Verkhratsky A, Tang Y. Pathological ATPergic Signaling in Major Depression and Bipolar Disorder. Front Mol Neurosci 2020; 12:331. [PMID: 32076399 PMCID: PMC7006450 DOI: 10.3389/fnmol.2019.00331] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2019] [Accepted: 12/26/2019] [Indexed: 12/11/2022] Open
Abstract
The mood disorders, major depression (MD) and bipolar disorder (BD), have a high lifetime prevalence in the human population and accordingly generate huge costs for health care. Efficient, rapidly acting, and side-effect-free pharmaceuticals are hitherto not available, and therefore, the identification of new therapeutic targets is an imperative task for (pre)clinical research. Such a target may be the purinergic P2X7 receptor (P2X7R), which is localized in the central nervous system (CNS) at microglial and neuroglial cells mediating neuroinflammation. MD and BD are due to neuroinflammation caused in the first line by the release of the pro-inflammatory cytokine interleukin-1β (IL-1β) from the microglia. IL-1β in turn induces the secretion of corticotropin-releasing hormone (CRH) and in consequence the secretion of adrenocorticotropic hormone (ACTH) and cortisol, which together with a plethora of further cytokines/chemokines lead to mood disorders. A number of biochemical/molecular biological measurements including the use of P2X7R- or IL-1β-deficient mice confirmed this chain of events. More recent studies showed that a decrease in the astrocytic release of ATP in the prefrontal cortex and hippocampus is a major cause of mood disorders. It is an attractive hypothesis that compensatory increases in P2X7Rs in these areas of the brain are the immediate actuators of MD and BD. Hence, blood-brain barrier-permeable P2X7R antagonists may be promising therapeutic tools to improve depressive disorders in humans.
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Affiliation(s)
- Peter Illes
- Rudolf-Boehm-Institut für Pharmakologie und Toxikologie, Universität Leipzig, Leipzig, Germany.,Acupuncture and Tuina School, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Alexei Verkhratsky
- Faculty of Life Sciences, The University of Manchester, Manchester, United Kingdom.,Achucarro Centre for Neuroscience, Ikerbasque, Basque Foundation for Science, Bilbao, Spain
| | - Yong Tang
- Acupuncture and Tuina School, Chengdu University of Traditional Chinese Medicine, Chengdu, China
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185
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Aghaie CI, Hausknecht KA, Wang R, Dezfuli PH, Haj-Dahmane S, Kane CJM, Sigurdson WJ, Shen RY. Prenatal Ethanol Exposure and Postnatal Environmental Intervention Alter Dopaminergic Neuron and Microglia Morphology in the Ventral Tegmental Area During Adulthood. Alcohol Clin Exp Res 2020; 44:435-444. [PMID: 31872887 DOI: 10.1111/acer.14275] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 12/13/2019] [Indexed: 12/27/2022]
Abstract
BACKGROUND Prenatal ethanol exposure (PE) impairs midbrain dopaminergic (DA) neuron function, which might contribute to various cognitive and behavioral deficits, including attention deficits and increased addiction risk, often observed in individuals with fetal alcohol spectrum disorders. Currently, the underlying mechanisms for PE-induced deficits are unclear. PE could lead to neuroinflammation by activating microglia, which play an important role in synaptic function. In the present study, we investigated PE effects on microglial activation and DA neuron density and morphology in the ventral tegmental area (VTA). Since postnatal environmental enrichment can reduce neuroinflammation and ameliorate several PE-induced behavioral deficits, we examined if a postnatal environmental intervention strategy using neonatal handling and postweaning complex housing could reverse PE effects on VTA DA neurons and microglia. METHODS Pregnant rats received 0 or 6 g/kg/d ethanol by 2 intragastric intubations on gestation days 8 to 20. After birth, rats were reared in the standard laboratory or enriched condition. Male adult rats (8 to 12 weeks old) were used for immunocytochemistry. RESULTS The results showed that PE decreased VTA DA neuron body size in standardly housed rats. Moreover, there was a significant decrease in numbers of VTA microglial branches and junctions in PE rats, suggesting morphological activation of microglia and possible neuroinflammation. The PE effects on microglia were normalized by postnatal environmental intervention, which also decreased the numbers of microglial branches and junctions in control animals, possibly via reduced stress. CONCLUSIONS Our findings show an association between PE-induced morphological activation of microglia and impaired DA neuron morphology in the VTA. Importantly, postnatal environmental intervention rescues possible PE-induced microglial activation. These data support that environmental intervention can be effective in ameliorating cognitive and behavioral deficits associated with VTA DA neuron dysfunctions, such as attention deficits and increased addiction risk.
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Affiliation(s)
- Claudia I Aghaie
- Department of Pathology and Anatomical Sciences, University at Buffalo, Buffalo, New York
| | - Kathryn A Hausknecht
- Department of Pharmacology and Toxicology, University at Buffalo, Buffalo, New York
| | - Ruixiang Wang
- Department of Pharmacology and Toxicology, University at Buffalo, Buffalo, New York
| | | | - Samir Haj-Dahmane
- Department of Pharmacology and Toxicology, University at Buffalo, Buffalo, New York
| | - Cynthia J M Kane
- Department of Neurobiology and Developmental Sciences, College of Medicine, the University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Wade J Sigurdson
- Department of Pathology and Anatomical Sciences, University at Buffalo, Buffalo, New York
| | - Roh-Yu Shen
- Department of Pathology and Anatomical Sciences, University at Buffalo, Buffalo, New York.,Department of Pharmacology and Toxicology, University at Buffalo, Buffalo, New York
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186
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Mishra PS, Raju TR. A Simple and Efficient Method for Concomitant Isolation and Culture of Enriched Astroglial and Microglial Cells from the Rat Spinal Cord. Bio Protoc 2020; 10:e3501. [PMID: 33654728 DOI: 10.21769/bioprotoc.3501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2019] [Revised: 12/16/2019] [Accepted: 12/17/2019] [Indexed: 11/02/2022] Open
Abstract
Investigations into glial biology have contributed substantially in understanding the physiology and pathology of the nervous system. However, intricacies of the neuron-glial and glial-glial interactions in vivo present significant challenges while delineating the individual cell-type contributions, thus making the in vitro techniques exceedingly relevant to study glial biology. However, obtaining optimal yield along with high purity has been challenging for microglial cultures. Here we present a simple protocol to establish enriched astroglial as well as microglial cultures from the neonatal rat spinal cord. This method results in highly enriched astroglial and microglial cultures with maximal yield.
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Affiliation(s)
- Pooja Shree Mishra
- Department of Neurophysiology, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, India
| | - Trichur R Raju
- Department of Neurophysiology, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, India
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187
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Díaz HS, Toledo C, Andrade DC, Marcus NJ, Del Rio R. Neuroinflammation in heart failure: new insights for an old disease. J Physiol 2020; 598:33-59. [PMID: 31671478 DOI: 10.1113/jp278864] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Accepted: 09/09/2019] [Indexed: 08/25/2023] Open
Abstract
Heart failure (HF) is a complex clinical syndrome affecting roughly 26 million people worldwide. Increased sympathetic drive is a hallmark of HF and is associated with disease progression and higher mortality risk. Several mechanisms contribute to enhanced sympathetic activity in HF, but these pathways are still incompletely understood. Previous work suggests that inflammation and activation of the renin-angiotensin system (RAS) increases sympathetic drive. Importantly, chronic inflammation in several brain regions is commonly observed in aged populations, and a growing body of evidence suggests neuroinflammation plays a crucial role in HF. In animal models of HF, central inhibition of RAS and pro-inflammatory cytokines normalizes sympathetic drive and improves cardiac function. The precise molecular and cellular mechanisms that lead to neuroinflammation and its effect on HF progression remain undetermined. This review summarizes the most recent advances in the field of neuroinflammation and autonomic control in HF. In addition, it focuses on cellular and molecular mediators of neuroinflammation in HF and in particular on brain regions involved in sympathetic control. Finally, we will comment on what is known about neuroinflammation in the context of preserved vs. reduced ejection fraction HF.
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Affiliation(s)
- Hugo S Díaz
- Laboratory of Cardiorespiratory Control, Department of Physiology, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Camilo Toledo
- Laboratory of Cardiorespiratory Control, Department of Physiology, Pontificia Universidad Católica de Chile, Santiago, Chile
- Centro de Excelencia en Biomedicina de Magallanes (CEBIMA), Universidad de Magallanes, Punta Arenas, Chile
| | - David C Andrade
- Laboratory of Cardiorespiratory Control, Department of Physiology, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Noah J Marcus
- Department of Physiology and Pharmacology, Des Moines University, Des Moines, IA, USA
| | - Rodrigo Del Rio
- Laboratory of Cardiorespiratory Control, Department of Physiology, Pontificia Universidad Católica de Chile, Santiago, Chile
- Centro de Envejecimiento y Regeneración (CARE-UC), Pontificia Universidad Católica de Chile, Santiago, Chile
- Centro de Excelencia en Biomedicina de Magallanes (CEBIMA), Universidad de Magallanes, Punta Arenas, Chile
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188
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Kolos EA, Korzhevskii DE. Spinal Cord Microglia in Health and Disease. Acta Naturae 2020; 12:4-17. [PMID: 32477594 PMCID: PMC7245960 DOI: 10.32607/actanaturae.10934] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Accepted: 11/09/2019] [Indexed: 12/11/2022] Open
Abstract
The review summarizes data of recent experimental studies on spinal microglia, the least explored cells of the spinal cord. It focuses on the origin and function of microglia in mammalian spinal cord embryogenesis. The main approaches to the classification of microgliocytes based on their structure, function, and immunophenotypic characteristics are analyzed. We discuss the results of studies conducted on experimental models of spinal cord diseases such as multiple sclerosis, amyotrophic lateral sclerosis, systemic inflammation, and some others, with special emphasis on the key role of microglia in the pathogenesis of these diseases. The review highlights the need to detect the new microglia-specific marker proteins expressed at all stages of ontogeny. New sensitive and selective microglial markers are necessary in order to improve identification of spinal cord microgliocytes in normal and pathological conditions. Possible morphometric methods to assess the functional activity of microglial cells are presented.
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Affiliation(s)
- E. A. Kolos
- Institute of Experimental Medicine, St. Petersburg, 197376 Russia
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189
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Hao X, Ou M, Zhang D, Zhao W, Yang Y, Liu J, Yang H, Zhu T, Li Y, Zhou C. The Effects of General Anesthetics on Synaptic Transmission. Curr Neuropharmacol 2020; 18:936-965. [PMID: 32106800 PMCID: PMC7709148 DOI: 10.2174/1570159x18666200227125854] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 01/20/2020] [Accepted: 02/26/2020] [Indexed: 02/08/2023] Open
Abstract
General anesthetics are a class of drugs that target the central nervous system and are widely used for various medical procedures. General anesthetics produce many behavioral changes required for clinical intervention, including amnesia, hypnosis, analgesia, and immobility; while they may also induce side effects like respiration and cardiovascular depressions. Understanding the mechanism of general anesthesia is essential for the development of selective general anesthetics which can preserve wanted pharmacological actions and exclude the side effects and underlying neural toxicities. However, the exact mechanism of how general anesthetics work is still elusive. Various molecular targets have been identified as specific targets for general anesthetics. Among these molecular targets, ion channels are the most principal category, including ligand-gated ionotropic receptors like γ-aminobutyric acid, glutamate and acetylcholine receptors, voltage-gated ion channels like voltage-gated sodium channel, calcium channel and potassium channels, and some second massager coupled channels. For neural functions of the central nervous system, synaptic transmission is the main procedure for which information is transmitted between neurons through brain regions, and intact synaptic function is fundamentally important for almost all the nervous functions, including consciousness, memory, and cognition. Therefore, it is important to understand the effects of general anesthetics on synaptic transmission via modulations of specific ion channels and relevant molecular targets, which can lead to the development of safer general anesthetics with selective actions. The present review will summarize the effects of various general anesthetics on synaptic transmissions and plasticity.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Yu Li
- Address correspondence to these authors at the Laboratory of Anesthesia & Critical Care Medicine, Translational Neuroscience Center, West China Hospital of Sichuan University, Chengdu 610041, Sichuan, P.R. China; E-mail: and Department of Anesthesiology, West China Hospital of Sichuan University, Chengdu, 610041, Sichuan, P.R. China; E-mail:
| | - Cheng Zhou
- Address correspondence to these authors at the Laboratory of Anesthesia & Critical Care Medicine, Translational Neuroscience Center, West China Hospital of Sichuan University, Chengdu 610041, Sichuan, P.R. China; E-mail: and Department of Anesthesiology, West China Hospital of Sichuan University, Chengdu, 610041, Sichuan, P.R. China; E-mail:
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190
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Abstract
The symptoms of Alzheimer disease reflect a loss of neural circuit integrity in the brain, but neurons do not work in isolation. Emerging evidence suggests that the intricate balance of interactions between neurons, astrocytes, microglia and vascular cells required for healthy brain function becomes perturbed during the disease, with early changes likely protecting neural circuits from damage, followed later by harmful effects when the balance cannot be restored. Moving beyond a neuronal focus to understand the complex cellular interactions in Alzheimer disease and how these change throughout the course of the disease may provide important insight into developing effective therapeutics.
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191
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Villa A, Gelosa P, Castiglioni L, Cimino M, Rizzi N, Pepe G, Lolli F, Marcello E, Sironi L, Vegeto E, Maggi A. Sex-Specific Features of Microglia from Adult Mice. Cell Rep 2019; 23:3501-3511. [PMID: 29924994 PMCID: PMC6024879 DOI: 10.1016/j.celrep.2018.05.048] [Citation(s) in RCA: 384] [Impact Index Per Article: 76.8] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Revised: 04/06/2018] [Accepted: 05/14/2018] [Indexed: 12/25/2022] Open
Abstract
Sex has a role in the incidence and outcome of neurological illnesses, also influencing the response to treatments. Neuroinflammation is involved in the onset and progression of several neurological diseases, and the fact that estrogens have anti-inflammatory activity suggests that these hormones may be a determinant in the sex-dependent manifestation of brain pathologies. We describe significant differences in the transcriptome of adult male and female microglia, possibly originating from perinatal exposure to sex steroids. Microglia isolated from adult brains maintain the sex-specific features when put in culture or transplanted in the brain of the opposite sex. Female microglia are neuroprotective because they restrict the damage caused by acute focal cerebral ischemia. This study therefore provides insight into a distinct perspective on the mechanisms underscoring a sexual bias in the susceptibility to brain diseases. Transcriptome sequencing indicates sexual differentiation in adult murine microglia Female microglia show a neuroprotective phenotype, independent from hormonal cues Female microglia phenotype is retained after transfer into male brains The presence of female microglia protects male brains from ischemic stroke
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Affiliation(s)
- Alessandro Villa
- Center of Excellence on Neurodegenerative Diseases of the University of Milan, Milan 20133, Italy; Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan 20133, Italy
| | - Paolo Gelosa
- Centro Cardiologico Monzino IRCCS, Milan 20138, Italy
| | - Laura Castiglioni
- Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan 20133, Italy
| | - Mauro Cimino
- Department of Biomolecular Sciences, University of Urbino, Urbino 61029, Italy
| | - Nicoletta Rizzi
- Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan 20133, Italy
| | - Giovanna Pepe
- Center of Excellence on Neurodegenerative Diseases of the University of Milan, Milan 20133, Italy; Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan 20133, Italy
| | - Federica Lolli
- Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan 20133, Italy
| | - Elena Marcello
- Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan 20133, Italy
| | - Luigi Sironi
- Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan 20133, Italy; Centro Cardiologico Monzino IRCCS, Milan 20138, Italy
| | - Elisabetta Vegeto
- Center of Excellence on Neurodegenerative Diseases of the University of Milan, Milan 20133, Italy; Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan 20133, Italy
| | - Adriana Maggi
- Center of Excellence on Neurodegenerative Diseases of the University of Milan, Milan 20133, Italy; Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan 20133, Italy.
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192
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Connexins-Based Hemichannels/Channels and Their Relationship with Inflammation, Seizures and Epilepsy. Int J Mol Sci 2019; 20:ijms20235976. [PMID: 31783599 PMCID: PMC6929063 DOI: 10.3390/ijms20235976] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 11/13/2019] [Accepted: 11/20/2019] [Indexed: 12/11/2022] Open
Abstract
Connexins (Cxs) are a family of 21 protein isoforms, eleven of which are expressed in the central nervous system, and they are found in neurons and glia. Cxs form hemichannels (connexons) and channels (gap junctions/electric synapses) that permit functional and metabolic coupling between neurons and astrocytes. Altered Cx expression and function is involved in inflammation and neurological diseases. Cxs-based hemichannels and channels have a relevance to seizures and epilepsy in two ways: First, this pathological condition increases the opening probability of hemichannels in glial cells to enable gliotransmitter release, sustaining the inflammatory process and exacerbating seizure generation and epileptogenesis, and second, the opening of channels favors excitability and synchronization through coupled neurons. These biological events highlight the global pathological mechanism of epilepsy, and the therapeutic potential of Cxs-based hemichannels and channels. Therefore, this review describes the role of Cxs in neuroinflammation and epilepsy and examines how the blocking of channels and hemichannels may be therapeutic targets of anti-convulsive and anti-epileptic treatments.
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193
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Guneykaya D, Ivanov A, Hernandez DP, Haage V, Wojtas B, Meyer N, Maricos M, Jordan P, Buonfiglioli A, Gielniewski B, Ochocka N, Cömert C, Friedrich C, Artiles LS, Kaminska B, Mertins P, Beule D, Kettenmann H, Wolf SA. Transcriptional and Translational Differences of Microglia from Male and Female Brains. Cell Rep 2019; 24:2773-2783.e6. [PMID: 30184509 DOI: 10.1016/j.celrep.2018.08.001] [Citation(s) in RCA: 292] [Impact Index Per Article: 58.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 04/19/2018] [Accepted: 07/31/2018] [Indexed: 02/07/2023] Open
Abstract
Sex differences in brain structure and function are of substantial scientific interest because of sex-related susceptibility to psychiatric and neurological disorders. Neuroinflammation is a common denominator of many of these diseases, and thus microglia, as the brain's immunocompetent cells, have come into focus in sex-specific studies. Here, we show differences in the structure, function, and transcriptomic and proteomic profiles in microglia freshly isolated from male and female mouse brains. We show that male microglia are more frequent in specific brain areas, have a higher antigen-presenting capacity, and appear to have a higher potential to respond to stimuli such as ATP, reflected in higher baseline outward and inward currents and higher protein expression of purinergic receptors. Altogether, we provide a comprehensive resource to generate and validate hypotheses regarding brain sex differences.
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Affiliation(s)
- Dilansu Guneykaya
- Cellular Neurocience, Max-Delbrueck-Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Andranik Ivanov
- Core Unit Bioinformatics, Berlin Institute of Health, Berlin, Germany; Charité-Universitaetsmedizin, Berlin, Germany
| | - Daniel Perez Hernandez
- Proteomics Platform, Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany; Berlin Institute of Health, 13125 Berlin, Germany
| | - Verena Haage
- Cellular Neurocience, Max-Delbrueck-Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Bartosz Wojtas
- Nencki Institute of Experimental Biology of the Polish Academy of Sciences, Warsaw, Poland
| | - Niklas Meyer
- Cellular Neurocience, Max-Delbrueck-Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Meron Maricos
- Cellular Neurocience, Max-Delbrueck-Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Philipp Jordan
- Cellular Neurocience, Max-Delbrueck-Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Alice Buonfiglioli
- Cellular Neurocience, Max-Delbrueck-Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany; Institute of Cell Biology and Neurobiology, Charité-Universitaetsmedizin, Berlin, Germany
| | - Bartlomiej Gielniewski
- Nencki Institute of Experimental Biology of the Polish Academy of Sciences, Warsaw, Poland
| | - Natalia Ochocka
- Nencki Institute of Experimental Biology of the Polish Academy of Sciences, Warsaw, Poland
| | - Cagla Cömert
- Cellular Neurocience, Max-Delbrueck-Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Corinna Friedrich
- Proteomics Platform, Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany
| | - Lorena Suarez Artiles
- Proteomics Platform, Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany
| | - Bozena Kaminska
- Nencki Institute of Experimental Biology of the Polish Academy of Sciences, Warsaw, Poland
| | - Philipp Mertins
- Proteomics Platform, Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany; Berlin Institute of Health, 13125 Berlin, Germany
| | - Dieter Beule
- Core Unit Bioinformatics, Berlin Institute of Health, Berlin, Germany; Max-Delbrueck-Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Helmut Kettenmann
- Cellular Neurocience, Max-Delbrueck-Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Susanne A Wolf
- Cellular Neurocience, Max-Delbrueck-Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany; Department of Ophthalmology, Charité-Universitaetsmedizin, Augustenburger Platz 1, 13353, Berlin, Germany.
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194
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Kiselev AV, Vedenkin AS, Stovbun IS, Sergienko VI, Kalinina TS. Calcium Salt of N-(5-Hydroxynicotinoyl)-L-Glutamic Acid Weakens Depressive-Like Behavior and Parkinsonian Syndrome in Experiment on Rodents. Bull Exp Biol Med 2019; 168:48-51. [DOI: 10.1007/s10517-019-04643-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Indexed: 11/29/2022]
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195
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Bordt EA, Ceasrine AM, Bilbo SD. Microglia and sexual differentiation of the developing brain: A focus on ontogeny and intrinsic factors. Glia 2019; 68:1085-1099. [PMID: 31743527 DOI: 10.1002/glia.23753] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 09/24/2019] [Accepted: 10/29/2019] [Indexed: 12/15/2022]
Abstract
Sexual differentiation of the brain during early development likely underlies the strong sex biases prevalent in many neurological conditions. Mounting evidence indicates that microglia, the innate immune cells of the central nervous system, are intricately involved in these sex-specific processes of differentiation. In this review, we synthesize literature demonstrating sex differences in microglial number, morphology, transcriptional state, and functionality throughout spatiotemporal development as well as highlight current literature regarding ontogeny of microglia. Along with vanRyzin et al. in this issue, we explore the idea that differences in microglia imparted by chromosomal or ontogeny-related programming can influence microglial-driven sexual differentiation of the brain, as well as the idea that extrinsic differences in the male and female brain microenvironment may in turn impart sex differences in microglia.
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Affiliation(s)
- Evan A Bordt
- Department of Pediatrics, Lurie Center for Autism, Massachusetts General Hospital for Children, Harvard Medical School, Boston, Massachusetts
| | - Alexis M Ceasrine
- Department of Psychology and Neuroscience, Duke University, Durham, North Carolina
| | - Staci D Bilbo
- Department of Pediatrics, Lurie Center for Autism, Massachusetts General Hospital for Children, Harvard Medical School, Boston, Massachusetts.,Department of Psychology and Neuroscience, Duke University, Durham, North Carolina
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196
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Saw G, Krishna K, Gupta N, Soong TW, Mallilankaraman K, Sajikumar S, Dheen ST. Epigenetic regulation of microglial phosphatidylinositol 3-kinase pathway involved in long-term potentiation and synaptic plasticity in rats. Glia 2019; 68:656-669. [PMID: 31702864 PMCID: PMC7003906 DOI: 10.1002/glia.23748] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 10/17/2019] [Accepted: 10/25/2019] [Indexed: 12/16/2022]
Abstract
Microglia are the main form of immune defense in the central nervous system. Microglia express phosphatidylinositol 3‐kinase (PI3K), which has been shown to play a significant role in synaptic plasticity in neurons and inflammation via microglia. This study shows that microglial PI3K is regulated epigenetically through histone modifications and posttranslationally through sumoylation and is involved in long‐term potentiation (LTP) by modulating the expression of brain‐derived neurotrophic factor (BDNF), which has been shown to be involved in neuronal synaptic plasticity. Sodium butyrate, a histone deacetylase inhibitor, upregulates PI3K expression, the phosphorylation of its downstream effectors, AKT and cAMP response element‐binding protein (CREB), and the expression of BDNF in microglia, suggesting that BDNF secretion is regulated in microglia via epigenetic regulation of PI3K. Further, knockdown of SUMO1 in BV2 microglia results in a decrease in the expression of PI3K, the phosphorylation of AKT and CREB, as well as the expression of BDNF. These results suggest that microglial PI3K is epigenetically regulated by histone modifications and posttranslationally modified by sumoylation, leading to altered expression of BDNF. Whole‐cell voltage‐clamp showed the involvement of microglia in neuronal LTP, as selective ablation or disruption of microglia with clodronate in rat hippocampal slices abolished LTP. However, LTP was rescued when the same hippocampal slices were treated with active PI3K or BDNF, indicating that microglial PI3K/AKT signaling contributes to LTP and synaptic plasticity. Understanding the mechanisms by which microglial PI3K influences synapses provides insights into the ways it can modulate synaptic transmission and plasticity in learning and memory.
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Affiliation(s)
- Genevieve Saw
- Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Kumar Krishna
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Neelima Gupta
- Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Tuck Wah Soong
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Karthik Mallilankaraman
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Sreedharan Sajikumar
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - S Thameem Dheen
- Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
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197
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Lainez NM, Coss D. Obesity, Neuroinflammation, and Reproductive Function. Endocrinology 2019; 160:2719-2736. [PMID: 31513269 PMCID: PMC6806266 DOI: 10.1210/en.2019-00487] [Citation(s) in RCA: 82] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 09/04/2019] [Indexed: 12/13/2022]
Abstract
The increasing occurrence of obesity has become a significant public health concern. Individuals with obesity have higher prevalence of heart disease, stroke, osteoarthritis, diabetes, and reproductive disorders. Reproductive problems include menstrual irregularities, pregnancy complications, and infertility due to anovulation, in women, and lower testosterone and diminished sperm count, in men. In particular, women with obesity have reduced levels of both gonadotropin hormones, and, in obese men, lower testosterone is accompanied by diminished LH. Taken together, these findings indicate central dysregulation of the hypothalamic-pituitary-gonadal axis, specifically at the level of the GnRH neuron function, which is the final brain output for the regulation of reproduction. Obesity is a state of hyperinsulinemia, hyperlipidemia, hyperleptinemia, and chronic inflammation. Herein, we review recent advances in our understanding of how these metabolic and immune changes affect hypothalamic function and regulation of GnRH neurons. In the latter part, we focus on neuroinflammation as a major consequence of obesity and discuss findings that reveal that GnRH neurons are uniquely positioned to respond to inflammatory changes.
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Affiliation(s)
- Nancy M Lainez
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, Riverside, California
| | - Djurdjica Coss
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, Riverside, California
- Correspondence: Djurdjica Coss, PhD, Division of Biomedical Sciences, School of Medicine, University of California, Riverside, 303 SOM Research Building, 900 University Avenue, Riverside, California 92521. E-mail:
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198
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Stowell RD, Sipe GO, Dawes RP, Batchelor HN, Lordy KA, Whitelaw BS, Stoessel MB, Bidlack JM, Brown E, Sur M, Majewska AK. Noradrenergic signaling in the wakeful state inhibits microglial surveillance and synaptic plasticity in the mouse visual cortex. Nat Neurosci 2019; 22:1782-1792. [PMID: 31636451 PMCID: PMC6875777 DOI: 10.1038/s41593-019-0514-0] [Citation(s) in RCA: 192] [Impact Index Per Article: 38.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 09/12/2019] [Indexed: 12/28/2022]
Abstract
Microglia are the brain's resident innate immune cells and also have a role in synaptic plasticity. Microglial processes continuously survey the brain parenchyma, interact with synaptic elements and maintain tissue homeostasis. However, the mechanisms that control surveillance and its role in synaptic plasticity are poorly understood. Microglial dynamics in vivo have been primarily studied in anesthetized animals. Here we report that microglial surveillance and injury response are reduced in awake mice as compared to anesthetized mice, suggesting that arousal state modulates microglial function. Pharmacologic stimulation of β2-adrenergic receptors recapitulated these observations and disrupted experience-dependent plasticity, and these effects required the presence of β2-adrenergic receptors in microglia. These results indicate that microglial roles in surveillance and synaptic plasticity in the mouse brain are modulated by noradrenergic tone fluctuations between arousal states and emphasize the need to understand the effect of disruptions of adrenergic signaling in neurodevelopment and neuropathology.
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Affiliation(s)
- Rianne D Stowell
- Department of Neuroscience, University of Rochester Medical Center, Rochester, NY, USA.,Neuroscience Graduate Program, University of Rochester Medical Center, Rochester, NY, USA
| | - Grayson O Sipe
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Ryan P Dawes
- Department of Neuroscience, University of Rochester Medical Center, Rochester, NY, USA.,Neuroscience Graduate Program, University of Rochester Medical Center, Rochester, NY, USA
| | - Hanna N Batchelor
- Department of Neuroscience, University of Rochester Medical Center, Rochester, NY, USA
| | - Katheryn A Lordy
- Department of Neuroscience, University of Rochester Medical Center, Rochester, NY, USA
| | - Brendan S Whitelaw
- Department of Neuroscience, University of Rochester Medical Center, Rochester, NY, USA.,Neuroscience Graduate Program, University of Rochester Medical Center, Rochester, NY, USA
| | - Mark B Stoessel
- Department of Neuroscience, University of Rochester Medical Center, Rochester, NY, USA.,Neuroscience Graduate Program, University of Rochester Medical Center, Rochester, NY, USA
| | - Jean M Bidlack
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, NY, USA
| | - Edward Brown
- Department of Biomedical Engineering, University of Rochester, Rochester, NY, USA
| | - Mriganka Sur
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Ania K Majewska
- Department of Neuroscience, University of Rochester Medical Center, Rochester, NY, USA. .,Center for Visual Science, University of Rochester Medical Center, Rochester, NY, USA.
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199
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Sierra A, Paolicelli RC, Kettenmann H. Cien Años de Microglía: Milestones in a Century of Microglial Research. Trends Neurosci 2019; 42:778-792. [PMID: 31635851 DOI: 10.1016/j.tins.2019.09.004] [Citation(s) in RCA: 123] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 09/09/2019] [Accepted: 09/10/2019] [Indexed: 12/11/2022]
Abstract
The year 2019 marks the 100-year anniversary of the discovery of microglia by Pío del Río-Hortega. We will recount the state of neuroscience research at the beginning of the 20th century and the heated scientific dispute regarding microglial identity. We will then walk through some of the milestones of microglial research in the decades since then. In the last 20 years, the field has grown exponentially. Researchers have shown that microglia are unlike any other resident macrophages: they have a unique origin and distinguishing features. Microglia are extraordinarily motile cells and constantly survey their environment, interacting with neurons, astrocytes, oligodendrocytes, neural stem cells, and infiltrating immune cells. We finally highlight some open questions for future research regarding microglia's identity, population dynamics, and dual (beneficial and detrimental) role in pathology.
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Affiliation(s)
- Amanda Sierra
- Achucarro Basque Center for Neuroscience, Ikerbasque Foundation, University of the Basque Country UPV/EHU, Parque Científico UPV/EHU, Barrio Sarriena s/n, Leioa, Bizkaia, 48940, Spain.
| | - Rosa C Paolicelli
- Department of Physiology, University of Lausanne, Rue du Bugnon 7, 1005 Lausanne, Switzerland.
| | - Helmut Kettenmann
- Max Delbrueck Center for Molecular Medicine in the Helmholtz Association, Cellular Neurosciences, Robert Roessle Str 10, 13092 Berlin, Germany.
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200
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Churchward MA, Michaud ER, Todd KG. Supporting microglial niches for therapeutic benefit in psychiatric disorders. Prog Neuropsychopharmacol Biol Psychiatry 2019; 94:109648. [PMID: 31078613 DOI: 10.1016/j.pnpbp.2019.109648] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 05/06/2019] [Accepted: 05/08/2019] [Indexed: 12/27/2022]
Abstract
Inflammation is an essential tissue response to injury, stress, or infection resulting in debris and/or pathogen clearance intended to promote healing and recovery. Due to the status as an immune 'privileged' tissue, microglia serve as endogenous regulators of inflammation in the central nervous system, but maintain communication with peripheral immune system to enable recruitment of peripheral immune cells in case of injury or infection. While microglia retain the functional capacity for a full range of inflammatory functions - microglia express a range of pattern-recognition receptors and function as innate immune cells, carry out phagocytosis of pathogens, and act as antigen presenting cells - in the healthy central nervous system (CNS) these functions are rarely engaged. Subsequently microglia are being recognized to occupy an increasing number of homeostatic niches, and in many cases have adopted immune or inflammatory mechanisms to carry out these niche functions absent immune activation. These sterile inflammatory functions are challenging long-held views of the role of inflammation in the central nervous system while simultaneously expanding the potential for the development of truly novel therapeutic interventions for a range of neuroinflammatory, neurodegenerative, and neuropsychiatric disorders. In the present review we discuss recent preclinical evidence for conserved niche functions for microglia whose disruption may causally contribute to various psychiatric disorders, and prospective targets for restoring disrupted niches.
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Affiliation(s)
- M A Churchward
- Neurochemical Research Unit, Department of Psychiatry, Faculty of Medicine, University of Alberta, Edmonton, AB T6G2R3, Canada; Neuroscience and Mental Health Institute, Faculty of Medicine, University of Alberta, Edmonton, AB T6G2R3, Canada.
| | - E R Michaud
- Neurochemical Research Unit, Department of Psychiatry, Faculty of Medicine, University of Alberta, Edmonton, AB T6G2R3, Canada; Neuroscience and Mental Health Institute, Faculty of Medicine, University of Alberta, Edmonton, AB T6G2R3, Canada
| | - K G Todd
- Neurochemical Research Unit, Department of Psychiatry, Faculty of Medicine, University of Alberta, Edmonton, AB T6G2R3, Canada; Neuroscience and Mental Health Institute, Faculty of Medicine, University of Alberta, Edmonton, AB T6G2R3, Canada; Department of Biomedical Engineering, University of Alberta, Edmonton, AB T6G2R3, Canada
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