1
|
Leavy A, Phelan J, Jimenez-Mateos EM. Contribution of microglia to the epileptiform activity that results from neonatal hypoxia. Neuropharmacology 2024; 253:109968. [PMID: 38692453 DOI: 10.1016/j.neuropharm.2024.109968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Revised: 04/13/2024] [Accepted: 04/22/2024] [Indexed: 05/03/2024]
Abstract
Microglia are described as the immune cells of the brain, their immune properties have been extensively studied since first described, however, their neural functions have only been explored over the last decade. Microglia have an important role in maintaining homeostasis in the central nervous system by surveying their surroundings to detect pathogens or damage cells. While these are the classical functions described for microglia, more recently their neural functions have been defined; they are critical to the maturation of neurons during embryonic and postnatal development, phagocytic microglia remove excess synapses during development, a process called synaptic pruning, which is important to overall neural maturation. Furthermore, microglia can respond to neuronal activity and, together with astrocytes, can regulate neural activity, contributing to the equilibrium between excitation and inhibition through a feedback loop. Hypoxia at birth is a serious neurological condition that disrupts normal brain function resulting in seizures and epilepsy later in life. Evidence has shown that microglia may contribute to this hyperexcitability after neonatal hypoxia. This review will summarize the existing data on the role of microglia in the pathogenesis of neonatal hypoxia and the plausible mechanisms that contribute to the development of hyperexcitability after hypoxia in neonates. This article is part of the Special Issue on "Microglia".
Collapse
Affiliation(s)
- Aisling Leavy
- Discipline of Physiology, School of Medicine, Trinity College Dublin, The University of Dublin, Dublin, Ireland
| | - Jessie Phelan
- Discipline of Physiology, School of Medicine, Trinity College Dublin, The University of Dublin, Dublin, Ireland
| | - Eva M Jimenez-Mateos
- Discipline of Physiology, School of Medicine, Trinity College Dublin, The University of Dublin, Dublin, Ireland.
| |
Collapse
|
2
|
Sakthivel PS, Scipioni L, Karam J, Keulen Z, Blurton-Jones M, Gratton E, Anderson AJ. Organelle phenotyping and multi-dimensional microscopy identify C1q as a novel regulator of microglial function. J Neurochem 2024. [PMID: 39018376 DOI: 10.1111/jnc.16173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 06/01/2024] [Accepted: 06/25/2024] [Indexed: 07/19/2024]
Abstract
Microglia, the immune cells of the central nervous system, are dynamic and heterogenous cells. While single cell RNA sequencing has become the conventional methodology for evaluating microglial state, transcriptomics do not provide insight into functional changes, identifying a critical gap in the field. Here, we propose a novel organelle phenotyping approach in which we treat live human induced pluripotent stem cell-derived microglia (iMGL) with organelle dyes staining mitochondria, lipids, lysosomes and acquire data by live-cell spectral microscopy. Dimensionality reduction techniques and unbiased cluster identification allow for recognition of microglial subpopulations with single-cell resolution based on organelle function. We validated this methodology using lipopolysaccharide and IL-10 treatment to polarize iMGL to an "inflammatory" and "anti-inflammatory" state, respectively, and then applied it to identify a novel regulator of iMGL function, complement protein C1q. While C1q is traditionally known as the initiator of the complement cascade, here we use organelle phenotyping to identify a role for C1q in regulating iMGL polarization via fatty acid storage and mitochondria membrane potential. Follow up evaluation of microglia using traditional read outs of activation state confirm that C1q drives an increase in microglia pro-inflammatory gene production and migration, while suppressing microglial proliferation. These data together validate the use of a novel organelle phenotyping approach and enable better mechanistic investigation of molecular regulators of microglial state.
Collapse
Affiliation(s)
- Pooja S Sakthivel
- Sue and Bill Gross Stem Cell Research Center, University of California, Irvine, California, USA
- Department of Anatomy and Neurobiology, University of California, Irvine, California, USA
| | - Lorenzo Scipioni
- Laboratory for Fluorescence Dynamics, Biomedical Engineering, University of California, Irvine, California, USA
| | - Josh Karam
- Sue and Bill Gross Stem Cell Research Center, University of California, Irvine, California, USA
| | - Zahara Keulen
- Sue and Bill Gross Stem Cell Research Center, University of California, Irvine, California, USA
- Department of Neurobiology and Behavior, University of California, Irvine, California, USA
| | - Mathew Blurton-Jones
- Sue and Bill Gross Stem Cell Research Center, University of California, Irvine, California, USA
- Department of Neurobiology and Behavior, University of California, Irvine, California, USA
- Institute for Memory Impairments and Neurological Disorders University of California, Irvine, California, USA
| | - Enrico Gratton
- Laboratory for Fluorescence Dynamics, Biomedical Engineering, University of California, Irvine, California, USA
| | - Aileen J Anderson
- Sue and Bill Gross Stem Cell Research Center, University of California, Irvine, California, USA
- Department of Anatomy and Neurobiology, University of California, Irvine, California, USA
- Institute for Memory Impairments and Neurological Disorders University of California, Irvine, California, USA
- Department of Physical Medicine and Rehabilitation, University of California, Irvine, California, USA
| |
Collapse
|
3
|
Marin-Rodero M, Reyes EC, Walker AJ, Jayewickreme T, Pinho-Ribeiro FA, Richardson Q, Jackson R, Chiu IM, Benoist C, Stevens B, Trejo JL, Mathis D. The meninges host a unique compartment of regulatory T cells that bulwarks adult hippocampal neurogenesis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.17.599387. [PMID: 38948783 PMCID: PMC11212874 DOI: 10.1101/2024.06.17.599387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/02/2024]
Abstract
Our knowledge about the meningeal immune system has recently burgeoned, particularly our understanding of how innate and adaptive effector cells are mobilized to meet brain challenges. However, information on how meningeal immunocytes guard brain homeostasis in healthy individuals remains sparse. This study highlights the heterogeneous and polyfunctional regulatory-T (Treg) cell compartment in the meninges. A Treg subtype specialized in controlling Th1-cell responses and another known to control responses in B-cell follicles were substantial components of this compartment, foretelling that punctual Treg-cell ablation rapidly unleashed interferon-gamma production by meningeal lymphocytes, unlocked their access to the brain parenchyma, and altered meningeal B-cell profiles. Distally, the hippocampus assumed a reactive state, with morphological and transcriptional changes in multiple glial-cell types; within the dentate gyrus, neural stem cells showed exacerbated death and desisted from further differentiation, associated with inhibition of spatial-reference memory. Thus, meningeal Treg cells are a multifaceted bulwark to brain homeostasis at steady-state. One sentence summary A distinct population of regulatory T cells in the murine meninges safeguards homeostasis by keeping local interferon-γ-producing lymphocytes in check, thereby preventing their invasion of the parenchyma, activation of hippocampal glial cells, death of neural stem cells, and memory decay.
Collapse
|
4
|
Nakaso K. Roles of Microglia in Neurodegenerative Diseases. Yonago Acta Med 2024; 67:1-8. [PMID: 38380436 PMCID: PMC10867232 DOI: 10.33160/yam.2024.02.001] [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: 01/11/2024] [Accepted: 01/24/2024] [Indexed: 02/22/2024]
Abstract
In recent years, microglia have attracted attention owing to their roles in various neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis. Microglia, which are brain-resident macrophages, not only act as immune cells but also perform other functions in the body. Interestingly, they exert contrasting effects on different neurodegenerative diseases. In addition to the previously reported M1 (toxic) and M2 (protective) types, microglia now also include disease-associated microglia owing to a more elaborate classification. Understanding this detailed classification is necessary to elucidate the association between microglia and neurodegenerative diseases. In this review, we discuss the diverse roles of microglia in neurodegenerative diseases and highlight their potential as therapeutic targets.
Collapse
Affiliation(s)
- Kazuhiro Nakaso
- Division of Biochemistry, Department of Pathophysiological and Therapeutic Sciences, School of Medicine, Faculty of Medicine, Tottori University, 683-8503 Yonago, Japan
| |
Collapse
|
5
|
Zhang X, Chen F, Sun M, Wu N, Liu B, Yi X, Ge R, Fan X. Microglia in the context of multiple sclerosis. Front Neurol 2023; 14:1157287. [PMID: 37360338 PMCID: PMC10287974 DOI: 10.3389/fneur.2023.1157287] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 05/10/2023] [Indexed: 06/28/2023] Open
Abstract
Multiple sclerosis (MS) is an inflammatory and neurodegenerative disease that commonly results in nontraumatic disability in young adults. The characteristic pathological hallmark of MS is damage to myelin, oligodendrocytes, and axons. Microglia provide continuous surveillance in the CNS microenvironment and initiate defensive mechanisms to protect CNS tissue. Additionally, microglia participate in neurogenesis, synaptic refinement, and myelin pruning through the expression and release of different signaling factors. Continuous activation of microglia has been implicated in neurodegenerative disorders. We first review the lifetime of microglia, including the origin, differentiation, development, and function of microglia. We then discuss microglia participate in the whole processes of remyelination and demyelination, microglial phenotypes in MS, and the NF-κB/PI3K-AKT signaling pathway in microglia. The damage to regulatory signaling pathways may change the homeostasis of microglia, which would accelerate the progression of MS.
Collapse
Affiliation(s)
- Xue Zhang
- Department of Neurology, Binzhou Medical University Hospital, Binzhou, China
| | - Fang Chen
- Department of Neurology, Binzhou Medical University Hospital, Binzhou, China
| | - Mingyue Sun
- Department of Neurology, Binzhou Medical University Hospital, Binzhou, China
| | - Nan Wu
- Department of Neurology, Binzhou Medical University Hospital, Binzhou, China
| | - Bin Liu
- Institute for Metabolic and Neuropsychiatric Disorders, Binzhou Medical University Hospital, Binzhou, China
| | - Xiangming Yi
- Department of Neurology, Binzhou Medical University Hospital, Binzhou, China
| | - Ruli Ge
- Department of Neurology, Binzhou Medical University Hospital, Binzhou, China
| | - Xueli Fan
- Department of Neurology, Binzhou Medical University Hospital, Binzhou, China
| |
Collapse
|
6
|
Rasia-Filho AA, Calcagnotto ME, von Bohlen Und Halbach O. Glial Cell Modulation of Dendritic Spine Structure and Synaptic Function. ADVANCES IN NEUROBIOLOGY 2023; 34:255-310. [PMID: 37962798 DOI: 10.1007/978-3-031-36159-3_6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Glia comprise a heterogeneous group of cells involved in the structure and function of the central and peripheral nervous system. Glial cells are found from invertebrates to humans with morphological specializations related to the neural circuits in which they are embedded. Glial cells modulate neuronal functions, brain wiring and myelination, and information processing. For example, astrocytes send processes to the synaptic cleft, actively participate in the metabolism of neurotransmitters, and release gliotransmitters, whose multiple effects depend on the targeting cells. Human astrocytes are larger and more complex than their mice and rats counterparts. Astrocytes and microglia participate in the development and plasticity of neural circuits by modulating dendritic spines. Spines enhance neuronal connectivity, integrate most postsynaptic excitatory potentials, and balance the strength of each input. Not all central synapses are engulfed by astrocytic processes. When that relationship occurs, a different pattern for thin and large spines reflects an activity-dependent remodeling of motile astrocytic processes around presynaptic and postsynaptic elements. Microglia are equally relevant for synaptic processing, and both glial cells modulate the switch of neuroendocrine secretion and behavioral display needed for reproduction. In this chapter, we provide an overview of the structure, function, and plasticity of glial cells and relate them to synaptic maturation and modulation, also involving neurotrophic factors. Together, neurons and glia coordinate synaptic transmission in both normal and abnormal conditions. Neglected over decades, this exciting research field can unravel the complexity of species-specific neural cytoarchitecture as well as the dynamic region-specific functional interactions between diverse neurons and glial subtypes.
Collapse
Affiliation(s)
- Alberto A Rasia-Filho
- Department of Basic Sciences/Physiology and Graduate Program in Biosciences, Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, RS, Brazil
- Graduate Program in Neuroscience, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Maria Elisa Calcagnotto
- Graduate Program in Neuroscience, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
- Department of Biochemistry, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
- Graduate Program in Biochemistry, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
- Graduate Program in Psychiatry and Behavioral Science, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | | |
Collapse
|
7
|
Paolicelli RC, Sierra A, Stevens B, Tremblay ME, Aguzzi A, Ajami B, Amit I, Audinat E, Bechmann I, Bennett M, Bennett F, Bessis A, Biber K, Bilbo S, Blurton-Jones M, Boddeke E, Brites D, Brône B, Brown GC, Butovsky O, Carson MJ, Castellano B, Colonna M, Cowley SA, Cunningham C, Davalos D, De Jager PL, de Strooper B, Denes A, Eggen BJL, Eyo U, Galea E, Garel S, Ginhoux F, Glass CK, Gokce O, Gomez-Nicola D, González B, Gordon S, Graeber MB, Greenhalgh AD, Gressens P, Greter M, Gutmann DH, Haass C, Heneka MT, Heppner FL, Hong S, Hume DA, Jung S, Kettenmann H, Kipnis J, Koyama R, Lemke G, Lynch M, Majewska A, Malcangio M, Malm T, Mancuso R, Masuda T, Matteoli M, McColl BW, Miron VE, Molofsky AV, Monje M, Mracsko E, Nadjar A, Neher JJ, Neniskyte U, Neumann H, Noda M, Peng B, Peri F, Perry VH, Popovich PG, Pridans C, Priller J, Prinz M, Ragozzino D, Ransohoff RM, Salter MW, Schaefer A, Schafer DP, Schwartz M, Simons M, Smith CJ, Streit WJ, Tay TL, Tsai LH, Verkhratsky A, von Bernhardi R, Wake H, Wittamer V, Wolf SA, Wu LJ, Wyss-Coray T. Microglia states and nomenclature: A field at its crossroads. Neuron 2022; 110:3458-3483. [PMID: 36327895 PMCID: PMC9999291 DOI: 10.1016/j.neuron.2022.10.020] [Citation(s) in RCA: 521] [Impact Index Per Article: 260.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 08/06/2022] [Accepted: 10/12/2022] [Indexed: 11/06/2022]
Abstract
Microglial research has advanced considerably in recent decades yet has been constrained by a rolling series of dichotomies such as "resting versus activated" and "M1 versus M2." This dualistic classification of good or bad microglia is inconsistent with the wide repertoire of microglial states and functions in development, plasticity, aging, and diseases that were elucidated in recent years. New designations continuously arising in an attempt to describe the different microglial states, notably defined using transcriptomics and proteomics, may easily lead to a misleading, although unintentional, coupling of categories and functions. To address these issues, we assembled a group of multidisciplinary experts to discuss our current understanding of microglial states as a dynamic concept and the importance of addressing microglial function. Here, we provide a conceptual framework and recommendations on the use of microglial nomenclature for researchers, reviewers, and editors, which will serve as the foundations for a future white paper.
Collapse
Affiliation(s)
- Rosa C Paolicelli
- Department of Biomedical Sciences, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland.
| | - Amanda Sierra
- Achucarro Basque Center for Neuroscience, Glial Cell Biology Lab, Leioa, Spain; Department of Neuroscience, University of the Basque Country EHU/UPV, Leioa, Spain; Ikerbasque Foundation, Bilbao, Spain.
| | - Beth Stevens
- Broad Institute of MIT and Harvard, Cambridge, MA, USA; Howard Hughes Medical Institute, (HHMI), MD, USA; Boston Children's Hospital, Boston, MA, USA.
| | - Marie-Eve Tremblay
- Centre de recherche du CHU de Québec-Université Laval, Québec City, QC, Canada; Department of Neurology and Neurosurgery, McGill University, Montréal, QC, Canada; Division of Medical Sciences, University of Victoria, Victoria, BC, Canada; Center for Advanced Materials and Related Technology (CAMTEC), University of Victoria, Victoria, BC, Canada; Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada.
| | - Adriano Aguzzi
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
| | - Bahareh Ajami
- Department of Molecular Microbiology & Immunology, Department of Behavioral and Systems Neuroscience, Oregon Health & Science University School of Medicine, Portland, OR, USA
| | - Ido Amit
- Department of Systems Immunology, Weizmann Institute of Science, Rehovot, Israel
| | - Etienne Audinat
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France
| | - Ingo Bechmann
- Institute of Anatomy, University of Leipzig, Leipzig, Germany
| | - Mariko Bennett
- Children's Hospital of Philadelphia, Department of Psychiatry, Department of Pediatrics, Division of Child Neurology, Philadelphia, PA, USA
| | - Frederick Bennett
- Children's Hospital of Philadelphia, University of Pennsylvania, Philadelphia, PA, USA
| | - Alain Bessis
- École Normale Supérieure, Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche Scientifique, Paris Sciences et Lettres Research University, Paris, France
| | - Knut Biber
- Neuroscience Discovery, AbbVie Deutschland GmbH, Ludwigshafen, Germany
| | - Staci Bilbo
- Departments of Psychology & Neuroscience, Neurobiology, and Cell Biology, Duke University, Durham, NC, USA
| | - Mathew Blurton-Jones
- Center for the Neurobiology of Learning and Memory, UCI MIND, University of California, Irvine, CA, USA
| | - Erik Boddeke
- Department Biomedical Sciences of Cells & Systems, Section Molecular Neurobiology, University of Groningen, University Medical Center, Groningen, the Netherlands
| | - Dora Brites
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Lisbon, Portugal
| | - Bert Brône
- BIOMED Research Institute, University of Hasselt, Hasselt, Belgium
| | - Guy C Brown
- Department of Biochemistry, University of Cambridge, Cambridge, UK
| | - Oleg Butovsky
- Ann Romney Center for Neurologic Diseases, Department Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Monica J Carson
- Center for Glial-Neuronal Interactions, Division of Biomedical Sciences, University of California Riverside School of Medicine, Riverside, CA, USA
| | - Bernardo Castellano
- Unidad de Histología Medica, Depto. Biología Celular, Fisiología e Inmunología, Barcelona, Spain; Instituto de Neurociencias, Universidad Autónoma de Barcelona, Barcelona, Spain
| | - Marco Colonna
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - Sally A Cowley
- James and Lillian Martin Centre for Stem Cell Research, Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Colm Cunningham
- School of Biochemistry & Immunology, Trinity Biomedical Sciences Institute, Trinity College, Dublin, Republic of Ireland; Trinity College Institute of Neuroscience, Trinity College, Dublin, Republic of Ireland
| | - Dimitrios Davalos
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA; Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Philip L De Jager
- Center for Translational & Computational Neuroimmunology, Department of Neurology, Columbia University Irving Medical Center, New York, NY, USA; Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY, USA
| | - Bart de Strooper
- UK Dementia Research Institute at University College London, London, UK; Vlaams Instituut voor Biotechnologie at Katholieke Universiteit Leuven, Leuven, Belgium
| | - Adam Denes
- "Momentum" Laboratory of Neuroimmunology, Institute of Experimental Medicine, Budapest, Hungary
| | - Bart J L Eggen
- Department of Biomedical Sciences of Cells & Systems, section Molecular Neurobiology, University of Groningen, Groningen, the Netherlands; University Medical Center Groningen, Groningen, the Netherlands
| | - Ukpong Eyo
- Department of Neuroscience, Center for Brain Immunology and Glia, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Elena Galea
- Institut de Neurociències and Departament de Bioquímica, Unitat de Bioquímica, Universitat Autònoma de Barcelona, Barcelona, Spain; ICREA, Barcelona, Spain
| | - Sonia Garel
- Institut de Biologie de l'ENS (IBENS), Département de Biologie, École Normale Supérieure, CNRS, INSERM, Paris, France; College de France, Paris, France
| | - Florent Ginhoux
- Singapore Immunology Network (SIgN), Agency for Science, Technology and Research (A(∗)STAR), Singapore, Singapore
| | | | - Ozgun Gokce
- Institute for Stroke and Dementia Research, Ludwig Maximillian's University of Munich, Munich, Germany
| | - Diego Gomez-Nicola
- School of Biological Sciences, University of Southampton, Southampton General Hospital, Southampton, UK
| | - Berta González
- Unidad de Histología Medica, Depto. Biología Celular, Fisiología e Inmunología and Instituto de Neurociencias, Universidad Autónoma de Barcelona, Barcelona, Spain
| | - Siamon Gordon
- Chang Gung University, Taoyuan City, Taiwan (ROC); Sir William Dunn School of Pathology, Oxford, UK
| | - Manuel B Graeber
- Ken Parker Brain Tumour Research Laboratories, Brain and Mind Centre, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, Australia
| | - Andrew D Greenhalgh
- Lydia Becker Institute of Immunology and Inflammation, Geoffrey Jefferson Brain Research Centre, Division of Infection, Immunity & Respiratory Medicine, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
| | - Pierre Gressens
- Université Paris Cité, Inserm, NeuroDiderot, 75019 Paris, France
| | - Melanie Greter
- Institute of Experimental Immunology, University of Zurich, Zurich, Switzerland
| | - David H Gutmann
- Department of Neurology, Washington University School of Medicine, St. Louis, MO, USA
| | - Christian Haass
- Division of Metabolic Biochemistry, Faculty of Medicine, Biomedical Center (BMC), Ludwig-Maximilians-Universität Munchen, Munich, Germany; German Center for Neurodegenerative Diseases (DZNE), Munich, Germany; Munich Cluster for Systems Neurology (SyNergy); Munich, Germany
| | - Michael T Heneka
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Belvaux, Luxembourg
| | - Frank L Heppner
- Department of Neuropathology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Soyon Hong
- UK Dementia Research Institute at University College London, London, UK
| | - David A Hume
- Mater Research Institute-University of Queensland, Brisbane, QLD, Australia
| | - Steffen Jung
- Department of Immunology and Regenerative Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Helmut Kettenmann
- Max-Delbrück Center for Molecular Medicine, Berlin, Germany; Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Jonathan Kipnis
- Center for Brain Immunology and Glia (BIG), Department of Pathology and Immunology, Washington University in St. Louis, St. Louis, MO, USA
| | - Ryuta Koyama
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Greg Lemke
- MNL-L, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Marina Lynch
- Trinity College Institute of Neuroscience, Trinity College, Dublin, Republic of Ireland
| | - Ania Majewska
- Department of Neuroscience, University of Rochester, Rochester, NY, USA
| | - Marzia Malcangio
- Wolfson Centre for Age-Related Diseases, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Tarja Malm
- University of Eastern Finland, Kuopio, Finland
| | - Renzo Mancuso
- Microglia and Inflammation in Neurological Disorders (MIND) Lab, VIB Center for Molecular Neurology, VIB, Antwerp, Belgium; Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium
| | - Takahiro Masuda
- Department of Molecular and System Pharmacology, Graduate School of Pharmaceutical Sciences, Kyushu University, Japan
| | - Michela Matteoli
- Humanitas University, Department of Biomedical Sciences, Milan, Italy
| | - Barry W McColl
- UK Dementia Research Institute, Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh BioQuarter, Edinburgh, UK
| | - Veronique E Miron
- MRC Centre for Reproductive Health, The Queen's Medical Research Institute, Edinburgh BioQuarter, Edinburgh, UK; UK Dementia Research Institute at the University of Edinburgh, Edinburgh BioQuarter, Edinburgh, UK
| | | | - Michelle Monje
- Howard Hughes Medical Institute, (HHMI), MD, USA; Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford University, Stanford, CA, USA
| | | | - Agnes Nadjar
- Neurocentre Magendie, University of Bordeaux, Bordeaux, France; Institut Universitaire de France (IUF), Paris, France
| | - Jonas J Neher
- German Center for Neurodegenerative Diseases (DZNE), Tübingen, Germany; Department of Cellular Neurology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Urte Neniskyte
- VU LSC-EMBL Partnership for Genome Editing Technologies, Life Sciences Center, Vilnius University, Vilnius, Lithuania; Institute of Biosciences, Life Sciences Center, Vilnius University, Vilnius, Lithuania
| | - Harald Neumann
- Institute of Reconstructive Neurobiology, Medical Faculty and University Hospital of Bonn, University of Bonn, Bonn, Germany
| | - Mami Noda
- Laboratory of Pathophysiology, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan; Institute of Mitochondrial Biology and Medicine of Xi'an Jiaotong University School of Life Science and Technology, Xi'an, China
| | - Bo Peng
- Department of Neurosurgery, Huashan Hospital, Institute for Translational Brain Research, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Fudan University, Shanghai, China
| | - Francesca Peri
- Department of Molecular Life Sciences, University of Zurich, Zurich, Switzerland
| | - V Hugh Perry
- UK Dementia Research Institute, University College London, London, UK; School of Biological Sciences, University of Southampton, Southampton, UK
| | - Phillip G Popovich
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH, USA
| | - Clare Pridans
- University of Edinburgh, Centre for Inflammation Research, Edinburgh, UK
| | - Josef Priller
- Department of Psychiatry & Psychotherapy, School of Medicine, Technical University of Munich, Munich, Germany; Charité - Universitätsmedizin Berlin and DZNE, Berlin, Germany; University of Edinburgh and UK DRI, Edinburgh, UK
| | - Marco Prinz
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, Freiburg, Germany; Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany; Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany
| | - Davide Ragozzino
- Department of Physiology and Pharmacology, Sapienza University of Rome, Rome, Italy; Santa Lucia Foundation (IRCCS Fondazione Santa Lucia), Rome, Italy
| | | | - Michael W Salter
- Hospital for Sick Children, Toronto, ON, Canada; University of Toronto, Toronto, ON, Canada
| | - Anne Schaefer
- Nash Family Department of Neuroscience, Center for Glial Biology, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Max Planck Institute for Biology of Ageing, Koeln, Germany
| | - Dorothy P Schafer
- Department of Neurobiology, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School, Worcester, MA, USA
| | - Michal Schwartz
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| | - Mikael Simons
- Institute of Neuronal Cell Biology, Technical University Munich, German Center for Neurodegenerative Diseases, Munich, Germany
| | - Cody J Smith
- Galvin Life Science Center, University of Notre Dame, Indianapolis, IN, USA
| | - Wolfgang J Streit
- Department of Neuroscience, University of Florida, Gainesville, FL, USA
| | - Tuan Leng Tay
- Faculty of Biology, University of Freiburg, Freiburg, Germany; BrainLinks-BrainTools Centre, University of Freiburg, Freiburg, Germany; Freiburg Institute of Advanced Studies, University of Freiburg, Freiburg, Germany; Department of Biology, Boston University, Boston, MA, USA; Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, MA, USA
| | - Li-Huei Tsai
- Broad Institute of MIT and Harvard, Cambridge, MA, USA; Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA, USA; Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Alexei Verkhratsky
- Achucarro Basque Center for Neuroscience, Glial Cell Biology Lab, Leioa, Spain; Department of Neuroscience, University of the Basque Country EHU/UPV, Leioa, Spain; Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
| | | | - Hiroaki Wake
- Department of Anatomy and Molecular Cell Biology, Graduate School of Medicine, Nagoya University, Nagoya, Japan
| | - Valérie Wittamer
- Institut de Recherche Interdisciplinaire en Biologie Humaine et Moléculaire (IRIBHM), Université Libre de Bruxelles (ULB), Brussels, Belgium; ULB Neuroscience Institute (UNI), Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Susanne A Wolf
- Charité Universitätsmedizin, Experimental Ophthalmology and Neuroimmunology, Berlin, Germany
| | - Long-Jun Wu
- Department of Neurology and Department of Immunology, Mayo Clinic, Rochester, MN, USA
| | - Tony Wyss-Coray
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford University, Stanford, CA, USA
| |
Collapse
|
8
|
Rosmus DD, Lange C, Ludwig F, Ajami B, Wieghofer P. The Role of Osteopontin in Microglia Biology: Current Concepts and Future Perspectives. Biomedicines 2022; 10:biomedicines10040840. [PMID: 35453590 PMCID: PMC9027630 DOI: 10.3390/biomedicines10040840] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/26/2022] [Accepted: 03/27/2022] [Indexed: 12/14/2022] Open
Abstract
The innate immune landscape of the central nervous system (CNS), including the brain and the retina, consists of different myeloid cell populations with distinct tasks to fulfill. Whereas the CNS borders harbor extraparenchymal CNS-associated macrophages whose main duty is to build up a defense against invading pathogens and other damaging factors from the periphery, the resident immune cells of the CNS parenchyma and the retina, microglia, are highly dynamic cells with a plethora of functions during homeostasis and disease. Therefore, microglia are constantly sensing their environment and closely interacting with surrounding cells, which is in part mediated by soluble factors. One of these factors is Osteopontin (OPN), a multifunctional protein that is produced by different cell types in the CNS, including microglia, and is upregulated in neurodegenerative and neuroinflammatory conditions. In this review, we discuss the current literature about the interaction between microglia and OPN in homeostasis and several disease entities, including multiple sclerosis (MS), Alzheimer’s and cerebrovascular diseases (AD, CVD), amyotrophic lateral sclerosis (ALS), age-related macular degeneration (AMD) and diabetic retinopathy (DR), in the context of the molecular pathways involved in OPN signaling shaping the function of microglia. As nearly all CNS diseases are characterized by pathological alterations in microglial cells, accompanied by the disturbance of the homeostatic microglia phenotype, the emergence of disease-associated microglia (DAM) states and their interplay with factors shaping the DAM-signature, such as OPN, is of great interest for therapeutical interventions in the future.
Collapse
Affiliation(s)
| | - Clemens Lange
- Eye Center, Freiburg Medical Center, University of Freiburg, 79106 Freiburg, Germany; (C.L.); (F.L.)
- Ophtha-Lab, Department of Ophthalmology, St. Franziskus Hospital, 48145 Muenster, Germany
| | - Franziska Ludwig
- Eye Center, Freiburg Medical Center, University of Freiburg, 79106 Freiburg, Germany; (C.L.); (F.L.)
| | - Bahareh Ajami
- Department of Microbiology and Immunology, Oregon Health and Science University, Portland, OR 97239, USA;
| | - Peter Wieghofer
- Institute of Anatomy, Leipzig University, 04103 Leipzig, Germany;
- Cellular Neuroanatomy, Institute of Theoretical Medicine, Medical Faculty, Augsburg University, 86159 Augsburg, Germany
- Correspondence:
| |
Collapse
|
9
|
Wieghofer P, Engelbert M, Chui TYP, Rosen RB, Sakamoto T, Sebag J. Hyalocyte origin, structure, and imaging. EXPERT REVIEW OF OPHTHALMOLOGY 2022; 17:233-248. [PMID: 36632192 PMCID: PMC9831111 DOI: 10.1080/17469899.2022.2100762] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Introduction Hyalocytes have been recognized as resident tissue macrophages of the vitreous body since the mid-19th century. Despite this, knowledge about their origin, turnover, and dynamics is limited. Areas covered Historically, initial studies on the origin of hyalocytes used light and electron microscopy. Modern investigations across species including rodents and humans will be described. Novel imaging is now available to study human hyalocytes in vivo. The shared ontogeny with retinal microglia and their eventual interdependence as well as differences will be discussed. Expert opinion Owing to a common origin as myeloid cells, hyalocytes and retinal microglia have similarities, but hyalocytes appear to be distinct as resident macrophages of the vitreous body.
Collapse
Affiliation(s)
- Peter Wieghofer
- Cellular Neuroanatomy, Institute of Theoretical Medicine, Medical Faculty, University of Augsburg, Universitätsstraße 2, 86159 Augsburg, Germany,Corresponding authors: Peter Wieghofer. , J Sebag.
| | - Michael Engelbert
- Vitreous Retina Macula Consultants of New York, New York, NY 10022, USA.,LuEsther T. Mertz Retinal Research Center, Manhattan Eye, Ear and Throat Hospital, New York, NY 10065, USA.,Department of Ophthalmology, New York University School of Medicine, New York, NY 10016, USA
| | - Toco YP Chui
- Department of Ophthalmology, New York Eye and Ear Infirmary of Mount Sinai, New York, New York; Department of Ophthalmology, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Richard B Rosen
- Department of Ophthalmology, New York Eye and Ear Infirmary of Mount Sinai, New York, New York; Department of Ophthalmology, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Taiji Sakamoto
- Department of Ophthalmology, Kagoshima University Graduate School of Medical and Dental Science, Kagoshima, Japan
| | - J Sebag
- Doheny Eye Institute, UCLA, Los Angeles, CA, USA.,Clinical Ophthalmology, Stein Eye Institute, Geffen School of Medicine, UCLA, Los Angeles, CA, USA.,VMR Institute for Vitreous Macula Retina, Huntington Beach, CA, USA.,Corresponding authors: Peter Wieghofer. , J Sebag.
| |
Collapse
|
10
|
Tremblay MÈ. Microglial functional alteration and increased diversity in the challenged brain: Insights into novel targets for intervention. Brain Behav Immun Health 2021; 16:100301. [PMID: 34589793 PMCID: PMC8474548 DOI: 10.1016/j.bbih.2021.100301] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 07/12/2021] [Accepted: 07/13/2021] [Indexed: 02/07/2023] Open
Abstract
Microglia are the resident immune cells of the central nervous system (CNS) parenchyma, which perform beneficial physiological roles across life. These immune cells actively maintain CNS health by clearing toxic debris and removing dysfunctional or degenerating cells. They also modify the wiring of neuronal circuits, by acting on the formation, modification, and elimination of synapses-the connections between neurons. Microglia furthermore recently emerged as highly diverse cells comprising several structural and functional states, indicating a far more critical involvement in orchestrating brain development, plasticity, behaviour, and cognition. Various environmental factors, together with the individual genetic predispositions, confer an increased risk for neurodevelopmental and neuropsychiatric disorders, as well as neurodegenerative diseases that include autism spectrum disorders, schizophrenia, major depressive disorder, and Alzheimer's disease, across life. Microglia are highly sensitive to chronic psychological stress, inadequate diet, viral/bacterial infection, pollution, and insufficient or altered sleep, especially during critical developmental periods, but also throughout life. These environmental challenges can compromise microglial physiological functions, resulting notably in defective neuronal circuit wiring, altered brain functional connectivity, and the onset of behavioral deficits into adolescence, adulthood, and aging. This short review provides a historical and technical perspective, notably focused on my contribution to the field, on how environmental challenges affect microglia, particularly their physiological functions, and increase their diversity, which provides novel targets for intervention.
Collapse
Affiliation(s)
- Marie-Ève Tremblay
- Axe Neurosciences, Centre de Recherche du CHU de Québec-Université Laval, Québec, QC, Canada
- Molecular Medicine Department, Université Laval, Québec City, QC, Canada
- Department of Neurology and Neurosurgery, McGill University, Montréal, QC, Canada
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- The Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, BC, Canada
| |
Collapse
|
11
|
Long-term in vivo two-photon imaging of the neuroinflammatory response to intracortical implants and micro-vessel disruptions in awake mice. Biomaterials 2021; 276:121060. [PMID: 34419839 DOI: 10.1016/j.biomaterials.2021.121060] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Revised: 07/16/2021] [Accepted: 08/04/2021] [Indexed: 12/17/2022]
Abstract
Our understanding of biomaterials in the brain have been greatly enhanced by advancements in in vivo imaging technologies such as two-photon microscopy. However, when applied to chronic studies, two-photon microscopy enables high-resolution imaging only in superficial regions due to inflammatory responses introduced by the craniotomy and insertion of foreign biomaterials. Microprisms provide a unique vertical view from brain surface to ~1 mm deep or more (depending on the size of the microprisms) which may break through this limitation on imaging depth. Although microprism has been used in the field of neuroscience, the in vivo foreign body responses to the microprism implant have yet to be fully elucidated. This is of important concern in broader applications of this approach, especially for neuroinflammation-sensitive studies. In this work, we first assessed the activation of microglia/macrophages for 16 weeks after microprism implantation using two-photon microscopy in awake CX3CR1-GFP mice. The imaging window became clear from bleedings after ~2 weeks and the maximum imaging distance (in the horizontal direction) stabilized at around 500 μm after ~5 weeks. We also quantified the microglial morphology from week 3 to week 16 post-implantation. Compared to non-implant controls, microglia near the microprism showed higher cell density, smaller soma, and shorter and less branched processes in the early-chronic phase. After week 5, microglial morphology further than 100 μm from the microprism was generally similar to microglia in the control group. In addition, time-lapse imaging confirmed that microglial processes were surveying normally from week 3, even for microglia as close as 50 μm away. These morphological analyses and dynamic imaging results suggest that microglia around chronically implanted microprism eventually exhibit inactive phenotypes. Next, we examined microglial/macrophage responses following laser induced micro-vessel disruptions as an example application of microprism implantation for neuroinflammation related studies. Through the microprism, we captured microglial/macrophage polarization and migration, as well as blood flow changes after the insult for additional 16 weeks. To our surprise, microglia/macrophage aggregation around the insult site was sustained over the 16-week observation period. This work demonstrates the feasibility of using microprisms for long-term characterizations of inflammatory responses to other injuries including implantable devices at deeper depths than that achievable by conventional two-photon microscopy.
Collapse
|
12
|
Carvalho-Paulo D, Bento Torres Neto J, Filho CS, de Oliveira TCG, de Sousa AA, dos Reis RR, dos Santos ZA, de Lima CM, de Oliveira MA, Said NM, Freitas SF, Sosthenes MCK, Gomes GF, Henrique EP, Pereira PDC, de Siqueira LS, de Melo MAD, Guerreiro Diniz C, Magalhães NGDM, Diniz JAP, Vasconcelos PFDC, Diniz DG, Anthony DC, Sherry DF, Brites D, Picanço Diniz CW. Microglial Morphology Across Distantly Related Species: Phylogenetic, Environmental and Age Influences on Microglia Reactivity and Surveillance States. Front Immunol 2021; 12:683026. [PMID: 34220831 PMCID: PMC8250867 DOI: 10.3389/fimmu.2021.683026] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 05/31/2021] [Indexed: 12/16/2022] Open
Abstract
Microglial immunosurveillance of the brain parenchyma to detect local perturbations in homeostasis, in all species, results in the adoption of a spectrum of morphological changes that reflect functional adaptations. Here, we review the contribution of these changes in microglia morphology in distantly related species, in homeostatic and non-homeostatic conditions, with three principal goals (1): to review the phylogenetic influences on the morphological diversity of microglia during homeostasis (2); to explore the impact of homeostatic perturbations (Dengue virus challenge) in distantly related species (Mus musculus and Callithrix penicillata) as a proxy for the differential immune response in small and large brains; and (3) to examine the influences of environmental enrichment and aging on the plasticity of the microglial morphological response following an immunological challenge (neurotropic arbovirus infection). Our findings reveal that the differences in microglia morphology across distantly related species under homeostatic condition cannot be attributed to the phylogenetic origin of the species. However, large and small brains, under similar non-homeostatic conditions, display differential microglial morphological responses, and we argue that age and environment interact to affect the microglia morphology after an immunological challenge; in particular, mice living in an enriched environment exhibit a more efficient immune response to the virus resulting in earlier removal of the virus and earlier return to the homeostatic morphological phenotype of microglia than it is observed in sedentary mice.
Collapse
Affiliation(s)
- Dario Carvalho-Paulo
- Laboratório de Investigações em Neurodegeneração e Infecção, Instituto de Ciências Biológicas, Hospital Universitário João de Barros Barreto, Universidade Federal do Pará, Belém, Brazil
| | - João Bento Torres Neto
- Laboratório de Investigações em Neurodegeneração e Infecção, Instituto de Ciências Biológicas, Hospital Universitário João de Barros Barreto, Universidade Federal do Pará, Belém, Brazil
- Faculdade de Fisioterapia e Terapia Ocupacional, Universidade Federal do Pará, Belém, Brazil
| | - Carlos Santos Filho
- Laboratório de Investigações em Neurodegeneração e Infecção, Instituto de Ciências Biológicas, Hospital Universitário João de Barros Barreto, Universidade Federal do Pará, Belém, Brazil
| | - Thais Cristina Galdino de Oliveira
- Laboratório de Investigações em Neurodegeneração e Infecção, Instituto de Ciências Biológicas, Hospital Universitário João de Barros Barreto, Universidade Federal do Pará, Belém, Brazil
| | - Aline Andrade de Sousa
- Laboratório de Investigações em Neurodegeneração e Infecção, Instituto de Ciências Biológicas, Hospital Universitário João de Barros Barreto, Universidade Federal do Pará, Belém, Brazil
| | - Renata Rodrigues dos Reis
- Laboratório de Investigações em Neurodegeneração e Infecção, Instituto de Ciências Biológicas, Hospital Universitário João de Barros Barreto, Universidade Federal do Pará, Belém, Brazil
| | - Zaire Alves dos Santos
- Laboratório de Investigações em Neurodegeneração e Infecção, Instituto de Ciências Biológicas, Hospital Universitário João de Barros Barreto, Universidade Federal do Pará, Belém, Brazil
| | - Camila Mendes de Lima
- Laboratório de Investigações em Neurodegeneração e Infecção, Instituto de Ciências Biológicas, Hospital Universitário João de Barros Barreto, Universidade Federal do Pará, Belém, Brazil
| | - Marcus Augusto de Oliveira
- Laboratório de Investigações em Neurodegeneração e Infecção, Instituto de Ciências Biológicas, Hospital Universitário João de Barros Barreto, Universidade Federal do Pará, Belém, Brazil
| | - Nivin Mazen Said
- Laboratório de Investigações em Neurodegeneração e Infecção, Instituto de Ciências Biológicas, Hospital Universitário João de Barros Barreto, Universidade Federal do Pará, Belém, Brazil
| | - Sinara Franco Freitas
- Laboratório de Investigações em Neurodegeneração e Infecção, Instituto de Ciências Biológicas, Hospital Universitário João de Barros Barreto, Universidade Federal do Pará, Belém, Brazil
| | - Marcia Consentino Kronka Sosthenes
- Laboratório de Investigações em Neurodegeneração e Infecção, Instituto de Ciências Biológicas, Hospital Universitário João de Barros Barreto, Universidade Federal do Pará, Belém, Brazil
| | - Giovanni Freitas Gomes
- Laboratório de Investigações em Neurodegeneração e Infecção, Instituto de Ciências Biológicas, Hospital Universitário João de Barros Barreto, Universidade Federal do Pará, Belém, Brazil
| | - Ediely Pereira Henrique
- Laboratório de Biologia Molecular e Neuroecologia, Instituto Federal de Educação Ciência e Tecnologia do Pará, Bragança, Brazil
| | - Patrick Douglas Côrrea Pereira
- Laboratório de Biologia Molecular e Neuroecologia, Instituto Federal de Educação Ciência e Tecnologia do Pará, Bragança, Brazil
| | - Lucas Silva de Siqueira
- Laboratório de Biologia Molecular e Neuroecologia, Instituto Federal de Educação Ciência e Tecnologia do Pará, Bragança, Brazil
| | - Mauro André Damasceno de Melo
- Laboratório de Biologia Molecular e Neuroecologia, Instituto Federal de Educação Ciência e Tecnologia do Pará, Bragança, Brazil
| | - Cristovam Guerreiro Diniz
- Laboratório de Biologia Molecular e Neuroecologia, Instituto Federal de Educação Ciência e Tecnologia do Pará, Bragança, Brazil
| | - Nara Gyzely de Morais Magalhães
- Laboratório de Biologia Molecular e Neuroecologia, Instituto Federal de Educação Ciência e Tecnologia do Pará, Bragança, Brazil
| | | | - Pedro Fernando da Costa Vasconcelos
- Dep. de Arbovirologia e Febres Hemorrágicas, Instituto Evandro Chagas, Belém, Brazil
- Departamento de Patologia, Universidade do Estado do Pará, Belém, Brazil
| | - Daniel Guerreiro Diniz
- Laboratório de Investigações em Neurodegeneração e Infecção, Instituto de Ciências Biológicas, Hospital Universitário João de Barros Barreto, Universidade Federal do Pará, Belém, Brazil
- Laboratório de Microscopia Eletrônica, Instituto Evandro Chagas, Belém, Brazil
| | | | - David Francis Sherry
- Department of Psychology, Advanced Facility for Avian Research, University of Western Ontario, London, ON, Canada
| | - Dora Brites
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Lisbon, Portugal
- Department of Pharmaceutical Sciences and Medicines, Faculty of Pharmacy, Universidade de Lisboa, Lisbon, Portugal
| | - Cristovam Wanderley Picanço Diniz
- Laboratório de Investigações em Neurodegeneração e Infecção, Instituto de Ciências Biológicas, Hospital Universitário João de Barros Barreto, Universidade Federal do Pará, Belém, Brazil
| |
Collapse
|
13
|
Awogbindin IO, Ben-Azu B, Olusola BA, Akinluyi ET, Adeniyi PA, Di Paolo T, Tremblay MÈ. Microglial Implications in SARS-CoV-2 Infection and COVID-19: Lessons From Viral RNA Neurotropism and Possible Relevance to Parkinson's Disease. Front Cell Neurosci 2021; 15:670298. [PMID: 34211370 PMCID: PMC8240959 DOI: 10.3389/fncel.2021.670298] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Accepted: 05/05/2021] [Indexed: 12/24/2022] Open
Abstract
Since December 2019, humankind has been experiencing a ravaging severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak, the second coronavirus pandemic in a decade after the Middle East respiratory syndrome coronavirus (MERS-CoV) disease in 2012. Infection with SARS-CoV-2 results in Coronavirus disease 2019 (COVID-19), which is responsible for over 3.1 million deaths worldwide. With the emergence of a second and a third wave of infection across the globe, and the rising record of multiple reinfections and relapses, SARS-CoV-2 infection shows no sign of abating. In addition, it is now evident that SARS-CoV-2 infection presents with neurological symptoms that include early hyposmia, ischemic stroke, meningitis, delirium and falls, even after viral clearance. This may suggest chronic or permanent changes to the neurons, glial cells, and/or brain vasculature in response to SARS-CoV-2 infection or COVID-19. Within the central nervous system (CNS), microglia act as the central housekeepers against altered homeostatic states, including during viral neurotropic infections. In this review, we highlight microglial responses to viral neuroinfections, especially those with a similar genetic composition and route of entry as SARS-CoV-2. As the primary sensor of viral infection in the CNS, we describe the pathogenic and neuroinvasive mechanisms of RNA viruses and SARS-CoV-2 vis-à-vis the microglial means of viral recognition. Responses of microglia which may culminate in viral clearance or immunopathology are also covered. Lastly, we further discuss the implication of SARS-CoV-2 CNS invasion on microglial plasticity and associated long-term neurodegeneration. As such, this review provides insight into some of the mechanisms by which microglia could contribute to the pathophysiology of post-COVID-19 neurological sequelae and disorders, including Parkinson's disease, which could be pervasive in the coming years given the growing numbers of infected and re-infected individuals globally.
Collapse
Affiliation(s)
- Ifeoluwa O. Awogbindin
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Neuroimmunology Group, Molecular Drug Metabolism and Toxicology Laboratory, Department of Biochemistry, College of Medicine, University of Ibadan, Ibadan, Nigeria
| | - Benneth Ben-Azu
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Neuropharmacology Unit, Department of Pharmacology and Therapeutics, Faculty of Basic Medical Sciences, College of Health Sciences, Delta State University, Abraka, Nigeria
| | - Babatunde A. Olusola
- Department of Virology, College of Medicine, University of Ibadan, Ibadan, Nigeria
| | - Elizabeth T. Akinluyi
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Department of Pharmacology and Therapeutics, College of Medicine and Health Sciences, Afe Babalola University, Ado-Ekiti, Nigeria
| | - Philip A. Adeniyi
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA, United States
| | - Therese Di Paolo
- Axe Neurosciences, Centre de Recherche du CHU de Québec-Université Laval, Québec, QC, Canada
- Faculté de Pharmacie, Université Laval, Québec, QC, Canada
| | - Marie-Ève Tremblay
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Axe Neurosciences, Centre de Recherche du CHU de Québec-Université Laval, Québec, QC, Canada
- Neurology and Neurosurgery Department, McGill University, Montréal, QC, Canada
- Department of Molecular Medicine, Université Laval, Québec, QC, Canada
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada
| |
Collapse
|
14
|
Wang J, Yue B, Zhang X, Guo X, Sun Z, Niu R. Effect of exercise on microglial activation and transcriptome of hippocampus in fluorosis mice. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 760:143376. [PMID: 33172640 DOI: 10.1016/j.scitotenv.2020.143376] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 10/02/2020] [Accepted: 10/21/2020] [Indexed: 06/11/2023]
Abstract
Fluorosis is a widespread endemic disease. Reports have shown that high fluoride causes the dysfunction of central nervous system (CNS) in animals. The neurotoxicity of fluoride may be related to the activation of microglia. Moreover, numerous studies have found that exercise facilitates the plasticity of structure and function in CNS, partly owing to the regulation of microglia activation. The present study was conducted to explore the effect of exercise on the microglial activation of hippocampus in fluorosis mice. One hundred adult female Institute of Cancer Research (ICR) mice were randomly divided into 4 groups: control group (group C, distilled water by gavage); exercise group (group E, distilled water by gavage and treadmill exercise); fluoride group [group F, 24 mg/kg sodium fluoride (NaF) by gavage]; fluoride plus exercise group (group F + E, 24 mg/kg NaF by gavage and treadmill exercise). After 8 weeks, hippocampal morphological structure, microglial activation and RNA transcriptome of mice in each group were evaluated by hematoxylin and eosin (HE) staining, Nissl staining, immunohistochemistry (IHC), quantitative real time PCR (QRT-PCR) and transcriptome sequencing. We discovered that the number of M1-type microglia in fluorosis-mice hippocampus was significantly increased when compared to group C; group F + E showed a decrease in the number of M1-type microglia with the comparison to group F. In addition, the hippocampal transcriptome analysis showed that 576 differential expression genes (DEG) were confirmed in group F, compared to group C, and 670 DEG were differently expressed in group F + E when compared to group F. Gene Ontology (GO) analysis showed that changed genes were implicated in regulation of transcription, DNA-templated, integral component of membrane and adenosine triphosphate (ATP) binding. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis of 670 DEG was helpful to find neuroactive ligand-receptor interaction pathway. In conclusion, these results indicate that treadmill running inhibits the excessive activation of microglia in hippocampus of the fluoride-toxic mice, accompanied with the alteration of neuroactive ligand-receptor interaction pathway.
Collapse
Affiliation(s)
- Jixiang Wang
- Shanxi Key Laboratory of Ecological Animal Science and Environmental Veterinary Medicine, College of Veterinary Medicine, Shanxi Agricultural University, Taigu, Shanxi 030801, China
| | - Baijuan Yue
- Shanxi Key Laboratory of Ecological Animal Science and Environmental Veterinary Medicine, College of Veterinary Medicine, Shanxi Agricultural University, Taigu, Shanxi 030801, China
| | - Xuhua Zhang
- Shanxi Key Laboratory of Ecological Animal Science and Environmental Veterinary Medicine, College of Veterinary Medicine, Shanxi Agricultural University, Taigu, Shanxi 030801, China
| | - Xin Guo
- Shanxi Key Laboratory of Ecological Animal Science and Environmental Veterinary Medicine, College of Veterinary Medicine, Shanxi Agricultural University, Taigu, Shanxi 030801, China
| | - Zilong Sun
- Shanxi Key Laboratory of Ecological Animal Science and Environmental Veterinary Medicine, College of Veterinary Medicine, Shanxi Agricultural University, Taigu, Shanxi 030801, China
| | - Ruiyan Niu
- Shanxi Key Laboratory of Ecological Animal Science and Environmental Veterinary Medicine, College of Veterinary Medicine, Shanxi Agricultural University, Taigu, Shanxi 030801, China.
| |
Collapse
|
15
|
Monitoring and Modulating Inflammation-Associated Alterations in Synaptic Plasticity: Role of Brain Stimulation and the Blood-Brain Interface. Biomolecules 2021; 11:biom11030359. [PMID: 33652912 PMCID: PMC7996828 DOI: 10.3390/biom11030359] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 02/18/2021] [Accepted: 02/20/2021] [Indexed: 12/20/2022] Open
Abstract
Inflammation of the central nervous system can be triggered by endogenous and exogenous stimuli such as local or systemic infection, trauma, and stroke. In addition to neurodegeneration and cell death, alterations in physiological brain functions are often associated with neuroinflammation. Robust experimental evidence has demonstrated that inflammatory cytokines affect the ability of neurons to express plasticity. It has been well-established that inflammation-associated alterations in synaptic plasticity contribute to the development of neuropsychiatric symptoms. Nevertheless, diagnostic approaches and interventional strategies to restore inflammatory deficits in synaptic plasticity are limited. Here, we review recent findings on inflammation-associated alterations in synaptic plasticity and the potential role of the blood–brain interface, i.e., the blood–brain barrier, in modulating synaptic plasticity. Based on recent findings indicating that brain stimulation promotes plasticity and modulates vascular function, we argue that clinically employed non-invasive brain stimulation techniques, such as transcranial magnetic stimulation, could be used for monitoring and modulating inflammation-induced alterations in synaptic plasticity.
Collapse
|
16
|
Scarante FF, Ribeiro MA, Almeida-Santos AF, Guimarães FS, Campos AC. Glial Cells and Their Contribution to the Mechanisms of Action of Cannabidiol in Neuropsychiatric Disorders. Front Pharmacol 2021; 11:618065. [PMID: 33613284 PMCID: PMC7890128 DOI: 10.3389/fphar.2020.618065] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 12/03/2020] [Indexed: 12/18/2022] Open
Abstract
Cannabidiol (CBD) is a phytocannabinoid with a broad-range of therapeutic potential in several conditions, including neurological (epilepsy, neurodegenerative diseases, traumatic and ischemic brain injuries) and psychiatric disorders (schizophrenia, addiction, major depressive disorder, and anxiety). The pharmacological mechanisms responsible for these effects are still unclear, and more than 60 potential molecular targets have been described. Regarding neuropsychiatric disorders, most studies investigating these mechanisms have focused on neuronal cells. However, glial cells (astrocytes, oligodendrocytes, microglia) also play a crucial role in keeping the homeostasis of the central nervous system. Changes in glial functions have been associated with neuropathological conditions, including those for which CBD is proposed to be useful. Mostly in vitro studies have indicated that CBD modulate the activation of proinflammatory pathways, energy metabolism, calcium homeostasis, and the proliferative rate of glial cells. Likewise, some of the molecular targets proposed for CBD actions are f expressed in glial cells, including pharmacological receptors such as CB1, CB2, PPAR-γ, and 5-HT1A. In the present review, we discuss the currently available evidence suggesting that part of the CBD effects are mediated by interference with glial cell function. We also propose additional studies that need to be performed to unveil the contribution of glial cells to CBD effects in neuropsychiatric disorders.
Collapse
Affiliation(s)
- Franciele F. Scarante
- Department of Pharmacology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Melissa A. Ribeiro
- Department of Pharmacology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Ana F. Almeida-Santos
- Department of Physiology and Biophysics, Biological Science Institute, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Francisco S. Guimarães
- Department of Pharmacology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Alline C. Campos
- Department of Pharmacology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| |
Collapse
|
17
|
Perea JR, Bolós M, Avila J. Microglia in Alzheimer's Disease in the Context of Tau Pathology. Biomolecules 2020; 10:biom10101439. [PMID: 33066368 PMCID: PMC7602223 DOI: 10.3390/biom10101439] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 10/09/2020] [Accepted: 10/10/2020] [Indexed: 12/13/2022] Open
Abstract
Microglia are the cells that comprise the innate immune system in the brain. First described more than a century ago, these cells were initially assigned a secondary role in the central nervous system (CNS) with respect to the protagonists, neurons. However, the latest advances have revealed the complexity and importance of microglia in neurodegenerative conditions such as Alzheimer’s disease (AD), the most common form of dementia associated with aging. This pathology is characterized by the accumulation of amyloid-β peptide (Aβ), which forms senile plaques in the neocortex, as well as by the aggregation of hyperphosphorylated tau protein, a process that leads to the development of neurofibrillary tangles (NFTs). Over the past few years, efforts have been focused on studying the interaction between Aβ and microglia, together with the ability of the latter to decrease the levels of this peptide. Given that most clinical trials following this strategy have failed, current endeavors focus on deciphering the molecular mechanisms that trigger the tau-induced inflammatory response of microglia. In this review, we summarize the most recent studies on the physiological and pathological functions of tau protein and microglia. In addition, we analyze the impact of microglial AD-risk genes (APOE, TREM2, and CD33) in tau pathology, and we discuss the role of extracellular soluble tau in neuroinflammation.
Collapse
Affiliation(s)
- Juan Ramón Perea
- Department of Molecular Neuropathology, Centro de Biología Molecular “Severo Ochoa” (CSIC-UAM), 1 Nicolás Cabrera, 28049 Madrid, Spain; (J.R.P.); (M.B.)
- Network Center for Biomedical Research on Neurodegenerative Diseases (CIBERNED), 5 Valderrebollo, 28031 Madrid, Spain
| | - Marta Bolós
- Department of Molecular Neuropathology, Centro de Biología Molecular “Severo Ochoa” (CSIC-UAM), 1 Nicolás Cabrera, 28049 Madrid, Spain; (J.R.P.); (M.B.)
- Network Center for Biomedical Research on Neurodegenerative Diseases (CIBERNED), 5 Valderrebollo, 28031 Madrid, Spain
| | - Jesús Avila
- Department of Molecular Neuropathology, Centro de Biología Molecular “Severo Ochoa” (CSIC-UAM), 1 Nicolás Cabrera, 28049 Madrid, Spain; (J.R.P.); (M.B.)
- Network Center for Biomedical Research on Neurodegenerative Diseases (CIBERNED), 5 Valderrebollo, 28031 Madrid, Spain
- Correspondence: ; Tel.:+34-196-4564
| |
Collapse
|
18
|
Holloway OG, King AE, Ziebell JM. Microglia Demonstrate Local Mixed Inflammation and a Defined Morphological Shift in an APP/PS1 Mouse Model. J Alzheimers Dis 2020; 77:1765-1781. [DOI: 10.3233/jad-200098] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Background: Microglia are traditionally described as the immune cells of the brain and have an inflammatory role in Alzheimer’s disease (AD). Microglial morphological and phenotypic shifts in AD have not been fully characterized; however, microglia are often described as either pro- or anti-inflammatory. Objective: To determine microglial if microglial morphology and phenotype changes with disease status. Methods: This study observed morphology through Iba1 immunohistochemistry on tissue sections encompassing the primary motor cortex and somatosensory barrel fields. Immunohistochemistry for pro-inflammatory markers: CD14 and CD40; and anti-inflammatory markers: CD16 and TREM2, was performed at 3, 6, and 12 months of age which correlated with pre-plaque, onset, and significant plaque load in APP/PS1 brains (n = 6) and compared to age-matched littermate controls (n = 6). Results: Microglia demonstrated a defined morphological shift with time. Deramified morphologies increased in the APP/PS1, at both 6 months (p < 0.0001) and 12 months (p < 0.0001). At 12 months, there were significantly lower numbers of ramified microglia (p < 0.001). Results indicated that microglia have a heterogenic marker immunoreactivity as CD16, TREM2, and CD40 were associated with an activated morphology at the same time points. All inflammatory markers were significantly upregulated at 12 months in the APP/PS1 mice (TREM2 (F (2,30) = 10.75, p = 0.0003), CD40 (F (2,30) = 15.86, p < 0.0001), CD14 (F (2,30) = 6.84, p = 0.0036), and CD16 (F (2,30) = 3.026, p = 0.0635)). Conclusion: Our data indicate that pro- and anti-inflammatory factors of microglia occur in APP/PS1 mice.
Collapse
Affiliation(s)
- Olivia G. Holloway
- Wicking Dementia Research and Education Centre, College of Health and Medicine, University of Tasmania, Tasmania, Australia
| | - Anna E. King
- Wicking Dementia Research and Education Centre, College of Health and Medicine, University of Tasmania, Tasmania, Australia
| | - Jenna M. Ziebell
- Wicking Dementia Research and Education Centre, College of Health and Medicine, University of Tasmania, Tasmania, Australia
| |
Collapse
|
19
|
Monga S, Weizman A, Gavish M. The Efficacy of the Novel TSPO Ligands 2-Cl-MGV-1 and 2,4-Di-Cl-MGV-1 Compared to the Classical TSPO Ligand PK 11195 to Counteract the Release of Chemokines from LPS-Stimulated BV-2 Microglial Cells. BIOLOGY 2020; 9:E291. [PMID: 32938018 PMCID: PMC7565396 DOI: 10.3390/biology9090291] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 09/08/2020] [Accepted: 09/10/2020] [Indexed: 12/15/2022]
Abstract
The impact of ligands of the 18 kDa translocator protein (TSPO) on the release of chemokines is not vastly investigated. In the present study, we assessed the effect of our novel TSPO ligands 2-Cl-MGV-1 and 2,4-Di-Cl-MGV-1 compared to the classical TSPO ligand PK 11195 on chemokine release in LPS-stimulated BV-2 microglial cells. As per the effect of 2-Cl-MGV-1, CCL2, CCL3, and CCL5 were inhibited by 90%, CCL8 by 97%, and IL-2 by 77% (p < 0.05 for all). 2,4-Di-Cl-MGV-1 inhibited CCL2 release by 92%, CCL3 by 91%, CCL5 by 90%, CCL8 by 89%, and IL-2 by 80% (p < 0.05 for all). PK 11195 exhibited weaker inhibitory effects: CCL2 by 22%, CCL3 by 83%, CCL5 by 34%, CCL8 by 41%, and the cytokine IL-2 by 14% (p < 0.05 for all). Thus, it appears that the novel TSPO ligands are potent suppressors of LPS-stimulated BV-2 microglial cells, and their inhibitory effect is larger than that of PK 11195. Such immunomodulatory effects on microglial cells may be relevant to the treatment of neurodegenerative and neuroinflammatory diseases.
Collapse
Affiliation(s)
- Sheelu Monga
- Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel;
| | - Abraham Weizman
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel;
- Research Unit, Geha Mental Health Center and Felsenstein Medical Research Center, Petah Tikva 4910002, Israel
| | - Moshe Gavish
- Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel;
| |
Collapse
|
20
|
Sabogal-Guáqueta AM, Marmolejo-Garza A, de Pádua VP, Eggen B, Boddeke E, Dolga AM. Microglia alterations in neurodegenerative diseases and their modeling with human induced pluripotent stem cell and other platforms. Prog Neurobiol 2020; 190:101805. [PMID: 32335273 DOI: 10.1016/j.pneurobio.2020.101805] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 03/16/2020] [Accepted: 04/09/2020] [Indexed: 12/13/2022]
Abstract
Microglia are the main innate immune cells of the central nervous system (CNS). Unlike neurons and glial cells, which derive from ectoderm, microglia migrate early during embryo development from the yolk-sac, a mesodermal-derived structure. Microglia regulate synaptic pruning during development and induce or modulate inflammation during aging and chronic diseases. Microglia are sensitive to brain injuries and threats, altering their phenotype and function to adopt a so-called immune-activated state in response to any perceived threat to the CNS integrity. Here, we present a short overview on the role of microglia in human neurodegenerative diseases and provide an update on the current model systems to study microglia, including cell lines, iPSC-derived microglia with an emphasis in their transcriptomic profile and integration into 3D brain organoids. We present various strategies to model and study their role in neurodegeneration providing a relevant platform for the development of novel and more effective therapies.
Collapse
Affiliation(s)
- Angélica María Sabogal-Guáqueta
- Department of Molecular Pharmacology, Faculty of Science and Engineering, Groningen Research Institute of Pharmacy, Behavioral and Cognitive Neurosciences (BCN), University of Groningen, Groningen, The Netherlands; Department of Biomedical Sciences of Cells & Systems, section Molecular Neurobiology, Faculty of Medical Sciences, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands; Neuroscience Group of Antioquia, Cellular and Molecular Neurobiology Area-School of Medicine, SIU, University of Antioquia, Medellín, Colombia
| | - Alejandro Marmolejo-Garza
- Department of Molecular Pharmacology, Faculty of Science and Engineering, Groningen Research Institute of Pharmacy, Behavioral and Cognitive Neurosciences (BCN), University of Groningen, Groningen, The Netherlands; Department of Biomedical Sciences of Cells & Systems, section Molecular Neurobiology, Faculty of Medical Sciences, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Vítor Passos de Pádua
- Department of Molecular Pharmacology, Faculty of Science and Engineering, Groningen Research Institute of Pharmacy, Behavioral and Cognitive Neurosciences (BCN), University of Groningen, Groningen, The Netherlands; Neurology Department, Medical School, University of São Paulo (USP), São Paulo, SP, Brazil
| | - Bart Eggen
- Department of Biomedical Sciences of Cells & Systems, section Molecular Neurobiology, Faculty of Medical Sciences, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Erik Boddeke
- Department of Biomedical Sciences of Cells & Systems, section Molecular Neurobiology, Faculty of Medical Sciences, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Amalia M Dolga
- Department of Molecular Pharmacology, Faculty of Science and Engineering, Groningen Research Institute of Pharmacy, Behavioral and Cognitive Neurosciences (BCN), University of Groningen, Groningen, The Netherlands.
| |
Collapse
|
21
|
Santiago AR, Madeira MH, Boia R, Aires ID, Rodrigues-Neves AC, Santos PF, Ambrósio AF. Keep an eye on adenosine: Its role in retinal inflammation. Pharmacol Ther 2020; 210:107513. [PMID: 32109489 DOI: 10.1016/j.pharmthera.2020.107513] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Adenosine is an endogenous purine nucleoside ubiquitously distributed throughout the body that interacts with G protein-coupled receptors, classified in four subtypes: A1R, A2AR, A2BR and A3R. Among the plethora of functions of adenosine, it has been increasingly recognized as a key mediator of the immune response. Neuroinflammation is a feature of chronic neurodegenerative diseases and contributes to the pathophysiology of several retinal degenerative diseases. Animal models of retinal diseases are helping to elucidate the regulatory roles of adenosine receptors in the development and progression of those diseases. Mounting evidence demonstrates that the adenosinergic system is altered in the retina during pathological conditions, compromising retinal physiology. This review focuses on the roles played by adenosine and the elements of the adenosinergic system (receptors, enzymes, transporters) in the neuroinflammatory processes occurring in the retina. An improved understanding of the molecular and cellular mechanisms of the signalling pathways mediated by adenosine underlying the onset and progression of retinal diseases will pave the way towards the identification of new therapeutic approaches.
Collapse
Affiliation(s)
- Ana Raquel Santiago
- Faculty of Medicine, Coimbra Institute for Clinical and Biomedical Research (iCBR), University of Coimbra, 3000-548 Coimbra, Portugal; Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3000-548 Coimbra, Portugal; Association for Innovation and Biomedical Research on Light and Image (AIBILI), Coimbra, 3000-548 Coimbra, Portugal.
| | - Maria H Madeira
- Faculty of Medicine, Coimbra Institute for Clinical and Biomedical Research (iCBR), University of Coimbra, 3000-548 Coimbra, Portugal; Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3000-548 Coimbra, Portugal; Association for Innovation and Biomedical Research on Light and Image (AIBILI), Coimbra, 3000-548 Coimbra, Portugal
| | - Raquel Boia
- Faculty of Medicine, Coimbra Institute for Clinical and Biomedical Research (iCBR), University of Coimbra, 3000-548 Coimbra, Portugal; Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3000-548 Coimbra, Portugal
| | - Inês Dinis Aires
- Faculty of Medicine, Coimbra Institute for Clinical and Biomedical Research (iCBR), University of Coimbra, 3000-548 Coimbra, Portugal; Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3000-548 Coimbra, Portugal
| | - Ana Catarina Rodrigues-Neves
- Faculty of Medicine, Coimbra Institute for Clinical and Biomedical Research (iCBR), University of Coimbra, 3000-548 Coimbra, Portugal; Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3000-548 Coimbra, Portugal
| | - Paulo Fernando Santos
- Faculty of Medicine, Coimbra Institute for Clinical and Biomedical Research (iCBR), University of Coimbra, 3000-548 Coimbra, Portugal; Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3000-548 Coimbra, Portugal; Department of Life Sciences, University of Coimbra, 3000-456 Coimbra, Portugal
| | - António Francisco Ambrósio
- Faculty of Medicine, Coimbra Institute for Clinical and Biomedical Research (iCBR), University of Coimbra, 3000-548 Coimbra, Portugal; Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3000-548 Coimbra, Portugal; Association for Innovation and Biomedical Research on Light and Image (AIBILI), Coimbra, 3000-548 Coimbra, Portugal.
| |
Collapse
|
22
|
Hashemiaghdam A, Mroczek M. Microglia heterogeneity and neurodegeneration: The emerging paradigm of the role of immunity in Alzheimer's disease. J Neuroimmunol 2020; 341:577185. [PMID: 32045774 DOI: 10.1016/j.jneuroim.2020.577185] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2019] [Revised: 02/01/2020] [Accepted: 02/01/2020] [Indexed: 12/22/2022]
Abstract
Alzheimer's disease (AD) is the most common dementia type affecting nearly 44 million people worldwide. Recent findings point to microglia as a significant contributor to neural development, neuroinflammation, and degeneration. Dysregulated immunoactivity in AD has been broadly studied, and current research on animal models enabled us to identify a new cluster of microglia (disease-associated microglia) alongside previously detected glial populations (e.g., plaque-associated microglia, dark microglia, Human Alzheimer's microglia) associated with neuroinflammation and with macrophagic activity. These distinct populations of glia show a spatial distribution within plaques with unique imaging features and distinct gene expression profile. Novel genetic approaches using single-nuclei RNA sequencing (sn-RNA seq) allowed researchers to identify gene expression profiles from fixed human samples. Recent studies, exposing transcriptomic clusters of disease-related cells and analyzing sequenced RNA from sorted myeloid cells, seem to confirm the hypothesis of the central role of glia in the pathogenesis of Alzheimer's disease. These discoveries may shed light on the effects of microglial activation and differences in gene expression profiles, furthering research towards the development of a cell-specific therapy. In this review, we examine recent studies that guide us towards recognizing the role of diverse populations of glial cells and their possible heterogeneous functional states in the pathogenesis of AD in humans.
Collapse
Affiliation(s)
| | - Magdalena Mroczek
- The John Walton Muscular Dystrophy Research Centre, Translational and Clinical Research Institute, Newcastle University and Newcastle Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK.
| |
Collapse
|
23
|
Hasselmann J, Blurton-Jones M. Human iPSC-derived microglia: A growing toolset to study the brain's innate immune cells. Glia 2020; 68:721-739. [PMID: 31926038 DOI: 10.1002/glia.23781] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 12/21/2019] [Accepted: 12/30/2019] [Indexed: 12/11/2022]
Abstract
Recent advances in the generation of microglia from human induced pluripotent stem cells (iPSCs) have provided exciting new approaches to examine and decipher the biology of microglia. As these techniques continue to evolve to encompass more complex in situ and in vivo paradigms, so too have they begun to yield novel scientific insight into the genetics and function of human microglia. As such, researchers now have access to a toolset comprised of three unique "flavors" of iPSC-derived microglia: in vitro microglia (iMGs), organoid microglia (oMGs), and xenotransplanted microglia (xMGs). The goal of this review is to discuss the variety of research applications that each of these techniques enables and to highlight recent discoveries that these methods have begun to uncover. By presenting the research paradigms in which each model has been successful, as well as the key benefits and limitations of each approach, it is our hope that this review will help interested researchers to incorporate these techniques into their studies, collectively advancing our understanding of human microglia biology.
Collapse
Affiliation(s)
- Jonathan Hasselmann
- Department of Neurobiology and Behavior, University of California Irvine, Irvine, California.,Sue and Bill Gross Stem Cell Research Center, University of California Irvine, Irvine, California.,Institute for Memory Impairments and Neurological Disorders, University of California Irvine, Irvine, California
| | - Mathew Blurton-Jones
- Department of Neurobiology and Behavior, University of California Irvine, Irvine, California.,Sue and Bill Gross Stem Cell Research Center, University of California Irvine, Irvine, California.,Institute for Memory Impairments and Neurological Disorders, University of California Irvine, Irvine, California
| |
Collapse
|
24
|
Boullerne AI, Feinstein DL. History of Neuroscience I. Pío del Río-Hortega (1882-1945): The Discoverer of Microglia and Oligodendroglia. ASN Neuro 2020; 12:1759091420953259. [PMID: 33070631 PMCID: PMC7580141 DOI: 10.1177/1759091420953259] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Affiliation(s)
- Anne I. Boullerne
- Department of Anesthesiology, University of Illinois, Chicago, Illinois
| | - Douglas L. Feinstein
- Department of Anesthesiology, University of Illinois, Chicago, Illinois
- Jesse Brown VAMC, Chicago, Illinois
| |
Collapse
|
25
|
Verkhratsky A, Rose CR. Na +-dependent transporters: The backbone of astroglial homeostatic function. Cell Calcium 2019; 85:102136. [PMID: 31835178 DOI: 10.1016/j.ceca.2019.102136] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2019] [Revised: 11/30/2019] [Accepted: 11/30/2019] [Indexed: 01/30/2023]
Abstract
Astrocytes are the principal homeostatic cells of the central nerves system (CNS) that support the CNS function at all levels of organisation, from molecular to organ. Several fundamental homeostatic functions of astrocytes are mediated through plasmalemmal pumps and transporters; most of which are also regulated by the transplasmalemmal gradient of Na+ ions. Neuronal activity as well as mechanical or chemical stimulation of astrocytes trigger plasmalemmal Na+ fluxes, which in turn generate spatio-temporally organised transient changes in the cytosolic Na+ concentration, which represent the substrate of astroglial Na+ signalling. Astroglial Na+ signals link and coordinate neuronal activity and CNS homeostatic demands with the astroglial homeostatic response.
Collapse
Affiliation(s)
- Alexei Verkhratsky
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, M13 9PT, UK; Achucarro Centre for Neuroscience, IKERBASQUE, Basque Foundation for Science, 48011, Bilbao, Spain.
| | - Christine R Rose
- Institute of Neurobiology, Faculty of Mathematics and Natural Sciences, Heinrich Heine University Düsseldorf, Universitätsstrasse 1, D-40225, Düsseldorf, Germany
| |
Collapse
|
26
|
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: 117] [Impact Index Per Article: 23.4] [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.
Collapse
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.
| |
Collapse
|
27
|
Stratoulias V, Venero JL, Tremblay MÈ, Joseph B. Microglial subtypes: diversity within the microglial community. EMBO J 2019. [PMID: 31373067 DOI: 10.15252/embj.2019a101997] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023] Open
Abstract
Microglia are brain-resident macrophages forming the first active immune barrier in the central nervous system. They fulfill multiple functions across development and adulthood and under disease conditions. Current understanding revolves around microglia acquiring distinct phenotypes upon exposure to extrinsic cues in their environment. However, emerging evidence suggests that microglia display differences in their functions that are not exclusively driven by their milieu, rather by the unique properties these cells possess. This microglial intrinsic heterogeneity has been largely overlooked, favoring the prevailing view that microglia are a single-cell type endowed with spectacular plasticity, allowing them to acquire multiple phenotypes and thereby fulfill their numerous functions in health and disease. Here, we review the evidence that microglia might form a community of cells in which each member (or "subtype") displays intrinsic properties and performs unique functions. Distinctive features and functional implications of several microglial subtypes are considered, across contexts of health and disease. Finally, we suggest that microglial subtype categorization shall be based on function and we propose ways for studying them. Hence, we advocate that plasticity (reaction states) and diversity (subtypes) should both be considered when studying the multitasking microglia.
Collapse
Affiliation(s)
- Vassilis Stratoulias
- Toxicology Unit, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Jose Luis Venero
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Sevilla, Sevilla, Spain.,Instituto de Biomedicina de Sevilla-Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Sevilla, Spain
| | - Marie-Ève Tremblay
- Department of Molecular Medicine, Université Laval, Quebec, QC, Canada.,Axe Neurosciences, Centre de Recherche du CHU de Québec-Université Laval, Quebec, QC, Canada
| | - Bertrand Joseph
- Toxicology Unit, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| |
Collapse
|
28
|
Stratoulias V, Venero JL, Tremblay M, Joseph B. Microglial subtypes: diversity within the microglial community. EMBO J 2019; 38:e101997. [PMID: 31373067 PMCID: PMC6717890 DOI: 10.15252/embj.2019101997] [Citation(s) in RCA: 313] [Impact Index Per Article: 62.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 04/29/2019] [Accepted: 05/03/2019] [Indexed: 12/03/2022] Open
Abstract
Microglia are brain-resident macrophages forming the first active immune barrier in the central nervous system. They fulfill multiple functions across development and adulthood and under disease conditions. Current understanding revolves around microglia acquiring distinct phenotypes upon exposure to extrinsic cues in their environment. However, emerging evidence suggests that microglia display differences in their functions that are not exclusively driven by their milieu, rather by the unique properties these cells possess. This microglial intrinsic heterogeneity has been largely overlooked, favoring the prevailing view that microglia are a single-cell type endowed with spectacular plasticity, allowing them to acquire multiple phenotypes and thereby fulfill their numerous functions in health and disease. Here, we review the evidence that microglia might form a community of cells in which each member (or "subtype") displays intrinsic properties and performs unique functions. Distinctive features and functional implications of several microglial subtypes are considered, across contexts of health and disease. Finally, we suggest that microglial subtype categorization shall be based on function and we propose ways for studying them. Hence, we advocate that plasticity (reaction states) and diversity (subtypes) should both be considered when studying the multitasking microglia.
Collapse
Affiliation(s)
- Vassilis Stratoulias
- Toxicology UnitInstitute of Environmental MedicineKarolinska InstitutetStockholmSweden
| | - Jose Luis Venero
- Departamento de Bioquímica y Biología MolecularFacultad de FarmaciaUniversidad de SevillaSevillaSpain
- Instituto de Biomedicina de Sevilla‐Hospital Universitario Virgen del Rocío/CSIC/Universidad de SevillaSevillaSpain
| | - Marie‐Ève Tremblay
- Department of Molecular MedicineUniversité LavalQuebecQCCanada
- Axe NeurosciencesCentre de Recherche du CHU de Québec‐Université LavalQuebecQCCanada
| | - Bertrand Joseph
- Toxicology UnitInstitute of Environmental MedicineKarolinska InstitutetStockholmSweden
| |
Collapse
|
29
|
Intravital 2-photon imaging reveals distinct morphology and infiltrative properties of glioblastoma-associated macrophages. Proc Natl Acad Sci U S A 2019; 116:14254-14259. [PMID: 31235603 DOI: 10.1073/pnas.1902366116] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Characterized by a dismal survival rate and limited response to therapy, glioblastoma (GBM) remains one of the most aggressive human malignancies. Recent studies of the role of tumor-associated macrophages (TAMs) in the progression of GBMs have demonstrated that TAMs are significant contributors to tumor growth, invasion, and therapeutic resistance. TAMs, which include brain-resident microglia and circulating bone marrow derived-monocytes (BMDMs), are typically grouped together in histopathological and molecular analyses due to the lack of reliable markers of distinction. To develop more effective therapies aimed at specific TAM populations, we must first understand how these cells differ both morphologically and behaviorally. Furthermore, we must develop a deeper understanding of the mechanisms encouraging their infiltration and how these mechanisms can be therapeutically exploited. In this study, we combined immunocompetent lineage tracing mouse models of GBM with high-resolution open-skull 2-photon microscopy to investigate the phenotypical and functional characteristics of TAMs. We demonstrate that TAMs are composed of 2 morphologically distinct cell types that have differential migratory propensities. We show that BMDMs are smaller, minimally branched cells that are highly migratory compared with microglia, which are larger, highly branched stationary cells. In addition, 2 populations of monocytic macrophages were observed that differed in terms of CX3CR1 expression and migratory capacity. Finally, we demonstrate the efficacy of anti-vascular endothelial growth factor A blockade for prohibiting TAM infiltration, especially against BMDMs. Taken together, our data clearly define characteristics of individual TAM populations and suggest that combination therapy with antivascular and antichemotaxis therapy may be an attractive option for treating these tumors.
Collapse
|
30
|
Ros-Bernal F, de Castro F. Fernando de Castro: Cajal's Man on the Peripheral Nervous System. Anat Rec (Hoboken) 2019; 303:1206-1214. [PMID: 31172650 DOI: 10.1002/ar.24191] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2018] [Revised: 12/13/2018] [Accepted: 12/28/2018] [Indexed: 11/08/2022]
Abstract
Santiago Ramón y Cajal developed his initial scientific career working alone. After the publication of his opus magna ("Textura del sistema nervioso del hombre y los vertebrados") and the general recognition of the scientific environments that crystallized with the concession of the International Moscow Prize (1900), the Spanish Government decided to officially support Cajal with a laboratory and the first salaries to pay collaborators. Is then when the Spanish Neurological School births: in 1902, Francisco Tello is the first one to be incorporated. With new additions, Cajal's work is complimented in new aspects, including Neuropathologies. Fernando de Castro is one of his youngest direct disciples, one of the closest and more beloved. Fernando de Castro worked from 1916 in Cajal's lab, until the death of El Maestro. He was specially committed by Cajal to unravel different aspects of the structure of the peripheral ganglia: sensitive and vegetative. Afterward, Fernando de Castro described by first time the nature of arterial chemoreceptors in the carotid body. While trying to confirm his anatomical description with physiological demonstrations, and accumulating delays because of scientific decision and the sociopolitical circumstances in Spain, Corneille Heymans was awarded with the Nobel Prize in Physiology or Medicine 1938 for his contributions to the knowledge of cardiorespiratory reflexes. The Karolinska Institutet forgot Heinrich Hering and Fernando de Castro in their decision. Undoubtedly, Fernando de Castro was the most important disciple of Cajal working in the different structures of the peripheral nervous system, and this work is now reviewed here. Anat Rec, 303:1206-1214, 2020. © 2019 American Association for Anatomy.
Collapse
Affiliation(s)
- Francisco Ros-Bernal
- Grupo de Neurotecnología, UP Medicina, Universitat Jaume I, Castellón de la Plana, Spain
| | - Fernando de Castro
- Grupo de Neurobiología del Desarrollo-GNDe, Instituto Cajal-CSIC, Madrid, Spain
| |
Collapse
|
31
|
de Castro F. Cajal and the Spanish Neurological School: Neuroscience Would Have Been a Different Story Without Them. Front Cell Neurosci 2019; 13:187. [PMID: 31178695 PMCID: PMC6542961 DOI: 10.3389/fncel.2019.00187] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Accepted: 04/12/2019] [Indexed: 02/02/2023] Open
Abstract
Santiago Ramón y Cajal was still young when he came across the reazione nera, discovered by the Italian Camillo Golgi. Cajal became absolutely entranced by the fine structure of the nervous system this technique revealed, which led him to embark on one of the last truly epic endeavors in Modern History: the characterization of nervous cells, and of their organization to form the brain. Cajal remained in Spain throughout his scientific career, working for years alone. With international recognition, Cajal began recruiting brilliant students as collaborators. A handful of his pupils also made decisive discoveries that served to lay the foundations of modern Neuroscience. Cajal's brother Pedro, Tello, Domingo Sánchez, Achúcarro, Lafora, Río-Hortega, de Castro and Lorente de Nó worked side by side with El Maestro. While Cajal himself pronounced some of the basic rules that have helped us to understand the nervous system (the neuron theory, the law of dynamic polarization of the neuron), as well as providing innumerable details about the histological organization of the different neural structures, it was Pío del Río-Hortega who identified two of the four main cell types in the CNS (oligodendrocytes and microglia), and Fernando de Castro who described the innervation of the blood vessels and identified the first chemoreceptors in the carotid body. Together, this group of scientists is known as the Spanish Neurological School, and if they had not existed, the History of Neuroscience would surely have been quite a different story; and proof that Cajal was a truly exceptional scientist but he was not an exception for Spanish Science.
Collapse
Affiliation(s)
- Fernando de Castro
- Grupo de Neurobiología del Desarrollo – GNDe, Instituto Cajal (CSIC), Madrid, Spain
| |
Collapse
|
32
|
Bar E, Barak B. Microglia roles in synaptic plasticity and myelination in homeostatic conditions and neurodevelopmental disorders. Glia 2019; 67:2125-2141. [DOI: 10.1002/glia.23637] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2019] [Revised: 04/15/2019] [Accepted: 04/16/2019] [Indexed: 12/28/2022]
Affiliation(s)
- Ela Bar
- The School of Psychological Sciences, Faculty of Social Sciences, and The Sagol School of NeuroscienceTel Aviv University Tel Aviv Israel
- The School of Neurobiology, Biochemistry & Biophysics, Faculty of Life SciencesTel Aviv University Tel Aviv Israel
| | - Boaz Barak
- The School of Psychological Sciences, Faculty of Social Sciences, and The Sagol School of NeuroscienceTel Aviv University Tel Aviv Israel
- The Sagol School of NeuroscienceTel Aviv University Tel Aviv Israel
| |
Collapse
|
33
|
Sharman MJ, Verdile G, Kirubakaran S, Parenti C, Singh A, Watt G, Karl T, Chang D, Li CG, Münch G. Targeting Inflammatory Pathways in Alzheimer's Disease: A Focus on Natural Products and Phytomedicines. CNS Drugs 2019; 33:457-480. [PMID: 30900203 DOI: 10.1007/s40263-019-00619-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Studies of the brains of Alzheimer's disease (AD) patients have revealed key neuropathological features, such as the deposition of aggregates of insoluble amyloid-β (Aβ) peptides and neurofibrillary tangles (NFTs). These pathological protein deposits, including Aβ peptides (which form senile plaques) and hyperphosphorylated tau (which aggregates into NFTs), have been assumed to be 'the cause of AD'. Aβ has been extensively targeted to develop an effective disease-modifying therapy, but with limited clinical success. Emerging therapies are also now targeting further pathological processes in AD, including neuroinflammation. This review focuses on the inflammatory and oxidative stress-related changes that occur in AD, and discusses some emerging anti-inflammatory natural products and phytomedicines. Many of the promising compounds are cytokine-suppressive anti-inflammatory drugs (CSAIDs), which target the proinflammatory AP1 and nuclear factor-κB signalling pathways and inhibit the expression of many proinflammatory cytokines, such as interleukin (IL)-1, IL-6, tumour necrosis factor-α, or nitric oxide produced by inducible nitric oxide synthase. However, many of these phytomedicines have not been tested in rigorous clinical trials in AD patients. It is not yet clear if the active compounds reach an effective concentration in the brain (due to limited bioavailability) or if they can slow down AD progression in long-term trials. The authors suggest that it is crucial for both the pharmacological and complementary medicine industries to conduct and fund those studies to significantly advance the field.
Collapse
Affiliation(s)
- Matthew J Sharman
- School of Health Sciences, College of Health and Medicine, University of Tasmania, Locked Bag 1322, Launceston, TAS, 7250, Australia
| | - Giuseppe Verdile
- School of Pharmacy and Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University, Bentley, WA, 6102, Australia
| | - Shanmugam Kirubakaran
- Department of Pharmacology, School of Medicine, Western Sydney University, Campbelltown, NSW, 2560, Australia
| | - Cristina Parenti
- Department of Pharmacology, School of Medicine, Western Sydney University, Campbelltown, NSW, 2560, Australia
| | - Ahilya Singh
- Department of Pharmacology, School of Medicine, Western Sydney University, Campbelltown, NSW, 2560, Australia
| | - Georgina Watt
- Department of Behavioural Neuroscience, School of Medicine, Western Sydney University, Campbelltown, NSW, 2560, Australia
| | - Tim Karl
- Department of Behavioural Neuroscience, School of Medicine, Western Sydney University, Campbelltown, NSW, 2560, Australia
| | - Dennis Chang
- NICM Health Research Institute, Western Sydney University, Campbelltown, NSW, 2560, Australia.,School of Science and Health, Western Sydney University, Campbelltown, NSW, 2560, Australia
| | - Chun Guang Li
- NICM Health Research Institute, Western Sydney University, Campbelltown, NSW, 2560, Australia
| | - Gerald Münch
- Department of Pharmacology, School of Medicine, Western Sydney University, Campbelltown, NSW, 2560, Australia. .,NICM Health Research Institute, Western Sydney University, Campbelltown, NSW, 2560, Australia. .,Pharmacology Unit, School of Medicine, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia.
| |
Collapse
|
34
|
Abstract
A century ago, Pío del Río-Hortega discovered that microglial cells are endowed with remarkable dynamic and plastic capabilities. The real-time plasticity of microglia could be revealed, however, only during the last 15 years with the development of new transgenic animal models and new molecular and functional analysis methods. Phenotyping microglia in situ with these new tools sealed the fate of the classical two state model of "resting" microglia in physiological conditions and "activated" microglia in pathological conditions. Our current view on functional behavior of microglia takes into account the exquisite reactivity of these immune cells to changes occurring in the CNS in both physiological and pathological conditions. We briefly review here the results and methods that have uncovered the dynamics and versatility of microglial reactivity.
Collapse
|
35
|
Ayana R, Singh S, Pati S. Deconvolution of Human Brain Cell Type Transcriptomes Unraveled Microglia-Specific Potential Biomarkers. Front Neurol 2018; 9:266. [PMID: 29755398 PMCID: PMC5932158 DOI: 10.3389/fneur.2018.00266] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 04/05/2018] [Indexed: 12/19/2022] Open
Abstract
Microglial cells form a context-dependent network of brain immunoeffector cells. Despite their indispensable roles, unresolved questions exist around biomarker discovery relevant to their cellular localization, self-renewing potential, and brain developmental dynamics. To resolve the existent gap in the annotation of candidate biomarkers, we conducted a meta-analysis of brain cells using available high-throughput data sets for deciphering microglia-specific expression profiles. We have identified 3,290 significant genes specific to microglia and further selected the top 20 dysregulated genes on the basis of p-value and log2FC. To this list, we added 7 known microglia-specific markers making the candidate list comprising 27 genes for further downstream analyses. Next, we established a connectome of these potential markers with their putative protein partners, which demonstrated strong associations of upregulated genes like Dedicator of cytokinesis 2 (DOCK2) with early/mature microglial markers such as Sphingosine kinase 1 (SPHK1), CD68, and CD45. To elucidate their respective brain anatomical location, we deconvoluted the BrainSpan Atlas expression data. This analysis showed high expression of the majority of candidate genes in microglia-dense regions (Amygdala, Hippocampus, Striatum) in the postnatal brain. Furthermore, to decipher their localized expression across brain ages, we constructed a developmental dynamics map (DDM) comprising extensive gene expression profiles throughout prenatal to postnatal stages, which resulted in the discovery of novel microglia-specific gene signatures. One of the interesting readout from DDM is that all the microglia-dense regions exhibit dynamic regulation of few genes at 37 post conception week (pcw), the transition period between pre- and postnatal stages. To validate these findings and correlate them as potential biomarkers, we analyzed the expression of corresponding proteins in hESC-derived human microglia precursors. The cultured microglial precursors showed expression of Pentraxin 3 (PTX3) and SPHK1 as well as several known markers like CD68, Allograft inflammatory factor 1 (AIF1/IBA1). In summary, this study has furnished critical insights into microglia dynamics across human brain ages and cataloged potential transcriptomic fingerprints that can be further exploited for designing novel neurotherapeutics.
Collapse
Affiliation(s)
- R Ayana
- Department of Life Sciences, School of Natural Sciences, Shiv Nadar University, Lucknow, India
| | - Shailja Singh
- Department of Life Sciences, School of Natural Sciences, Shiv Nadar University, Lucknow, India.,Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, India
| | - Soumya Pati
- Department of Life Sciences, School of Natural Sciences, Shiv Nadar University, Lucknow, India
| |
Collapse
|
36
|
Savage JC, Picard K, González-Ibáñez F, Tremblay MÈ. A Brief History of Microglial Ultrastructure: Distinctive Features, Phenotypes, and Functions Discovered Over the Past 60 Years by Electron Microscopy. Front Immunol 2018; 9:803. [PMID: 29922276 PMCID: PMC5996933 DOI: 10.3389/fimmu.2018.00803] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 04/03/2018] [Indexed: 01/01/2023] Open
Abstract
The first electron microscope was constructed in 1931. Several decades later, techniques were developed to allow the first ultrastructural analysis of microglia by transmission electron microscopy (EM). In the 50 years that followed, important roles of microglia have been identified, specifically due to the ultrastructural resolution currently available only with EM. In particular, the addition of electron-dense staining using immunohistochemical EM methods has allowed the identification of microglial cell bodies, as well as processes, which are difficult to recognize in EM, and to uncover their complex interactions with neurons and synapses. The ability to recognize neuronal, astrocytic, and oligodendrocytic compartments in the neuropil without any staining is another invaluable advantage of EM over light microscopy for studying intimate cell-cell contacts. The technique has been essential in defining microglial interactions with neurons and synapses, thus providing, among other discoveries, important insights into their roles in synaptic stripping and pruning via phagocytosis of extraneous synapses. Recent technological advances in EM including serial block-face imaging and focused-ion beam scanning EM have also facilitated automated acquisition of large tissue volumes required to reconstruct neuronal circuits in 3D at nanometer-resolution. These cutting-edge techniques which are now becoming increasingly available will further revolutionize the study of microglia across stages of the lifespan, brain regions, and contexts of health and disease. In this mini-review, we will focus on defining the distinctive ultrastructural features of microglia and the unique insights into their function that were provided by EM.
Collapse
Affiliation(s)
- Julie C. Savage
- Axe neurosciences, Centre de Recherche du CHU de Québec – Université Laval, Québec City, QC, Canada
- Département de médecine moléculaire, Université Laval, Québec City, QC, Canada
| | - Katherine Picard
- Axe neurosciences, Centre de Recherche du CHU de Québec – Université Laval, Québec City, QC, Canada
- Département de médecine moléculaire, Université Laval, Québec City, QC, Canada
| | - Fernando González-Ibáñez
- Axe neurosciences, Centre de Recherche du CHU de Québec – Université Laval, Québec City, QC, Canada
- Département de médecine moléculaire, Université Laval, Québec City, QC, Canada
| | - Marie-Ève Tremblay
- Axe neurosciences, Centre de Recherche du CHU de Québec – Université Laval, Québec City, QC, Canada
- Département de médecine moléculaire, Université Laval, Québec City, QC, Canada
| |
Collapse
|
37
|
Paolicelli RC, Bergamini G, Rajendran L. Cell-to-cell Communication by Extracellular Vesicles: Focus on Microglia. Neuroscience 2018; 405:148-157. [PMID: 29660443 DOI: 10.1016/j.neuroscience.2018.04.003] [Citation(s) in RCA: 239] [Impact Index Per Article: 39.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 03/30/2018] [Accepted: 04/04/2018] [Indexed: 12/20/2022]
Abstract
Extracellular vesicles, including exosomes and microvesicles, are small, nano-to-micrometer vesicles that are released from cells. While initially observed in immune cells and reticulocytes as vesicles meant to remove archaic proteins, now they have been observed in almost all cell types of multicellular organisms. Growing evidence indicates that extracellular vesicles, containing lipids, proteins and RNAs, represent an efficient way to transfer functional cargoes from one cell to another. In the central nervous system, the extensive cross-talk ongoing between neurons and glia, including microglia, the immune cells of the brain, takes advantage of secreted vesicles, which mediate intercellular communication over long range distance. Recent literature supports a critical role for extracellular vesicles in mediating complex and coordinated communication among neurons, astrocytes and microglia, both in the healthy and in the diseased brain. In this review, we focus on the biogenesis and function of microglia-related extracellular vesicles and focus on their putative role in Alzheimer's disease pathology.
Collapse
Affiliation(s)
- Rosa C Paolicelli
- Systems and Cell Biology of Neurodegeneration, IREM - Institute for Regenerative Medicine, University of Zurich, Switzerland.
| | - Giorgio Bergamini
- Preclinical Laboratory for Translational Research into Affective Disorders (PLaTRAD), Department of Psychiatry, Psychotherapy and Psychosomatics, University of Zurich, Switzerland
| | - Lawrence Rajendran
- Systems and Cell Biology of Neurodegeneration, IREM - Institute for Regenerative Medicine, University of Zurich, Switzerland
| |
Collapse
|
38
|
Sulzer D, Cassidy C, Horga G, Kang UJ, Fahn S, Casella L, Pezzoli G, Langley J, Hu XP, Zucca FA, Isaias IU, Zecca L. Neuromelanin detection by magnetic resonance imaging (MRI) and its promise as a biomarker for Parkinson's disease. NPJ PARKINSONS DISEASE 2018; 4:11. [PMID: 29644335 PMCID: PMC5893576 DOI: 10.1038/s41531-018-0047-3] [Citation(s) in RCA: 146] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 03/05/2018] [Accepted: 03/08/2018] [Indexed: 11/10/2022]
Abstract
The diagnosis of Parkinson’s disease (PD) occurs after pathogenesis is advanced and many substantia nigra (SN) dopamine neurons have already died. Now that therapies to block this neuronal loss are under development, it is imperative that the disease be diagnosed at earlier stages and that the response to therapies is monitored. Recent studies suggest this can be accomplished by magnetic resonance imaging (MRI) detection of neuromelanin (NM), the characteristic pigment of SN dopaminergic, and locus coeruleus (LC) noradrenergic neurons. NM is an autophagic product synthesized via oxidation of catecholamines and subsequent reactions, and in the SN and LC it increases linearly during normal aging. In PD, however, the pigment is lost when SN and LC neurons die. As shown nearly 25 years ago by Zecca and colleagues, NM’s avid binding of iron provides a paramagnetic source to enable electron and nuclear magnetic resonance detection, and thus a means for safe and noninvasive measure in living human brain. Recent technical improvements now provide a means for MRI to differentiate between PD patients and age-matched healthy controls, and should be able to identify changes in SN NM with age in individuals. We discuss how MRI detects NM and how this approach might be improved. We suggest that MRI of NM can be used to confirm PD diagnosis and monitor disease progression. We recommend that for subjects at risk for PD, and perhaps generally for older people, that MRI sequences performed at regular intervals can provide a pre-clinical means to detect presymptomatic PD.
Collapse
Affiliation(s)
- David Sulzer
- 1Department of Psychiatry, Columbia University Medical Center , New York State Psychiatric Institute, New York, NY USA.,2Department of Neurology, Columbia University Medical Center, New York, NY USA.,3Department of Pharmacology, Columbia University Medical Center, New York, NY USA
| | - Clifford Cassidy
- 4The Royal's Institute of Mental Health Research, Affiliated with the University of Ottawa, Ottawa, ON Canada
| | - Guillermo Horga
- 1Department of Psychiatry, Columbia University Medical Center , New York State Psychiatric Institute, New York, NY USA
| | - Un Jung Kang
- 2Department of Neurology, Columbia University Medical Center, New York, NY USA
| | - Stanley Fahn
- 2Department of Neurology, Columbia University Medical Center, New York, NY USA
| | - Luigi Casella
- 5Department of Chemistry, University of Pavia, Pavia, Italy
| | - Gianni Pezzoli
- Parkinson Institute, ASST "Gaetano Pini-CTO", Milan, Italy
| | - Jason Langley
- 7Center for Advanced NeuroImaging, University of California Riverside, Riverside, CA USA
| | - Xiaoping P Hu
- 8Department of Bioengineering, University of California Riverside, Riverside, CA USA
| | - Fabio A Zucca
- 9Institute of Biomedical Technologies, National Research Council of Italy, Milan, Italy
| | - Ioannis U Isaias
- Department of Neurology, University Hospital and Julius-Maximillian-University, Wuerzburg, Germany
| | - Luigi Zecca
- 9Institute of Biomedical Technologies, National Research Council of Italy, Milan, Italy
| |
Collapse
|
39
|
Microglia and Neonatal Brain Injury. Neuroscience 2018; 405:68-76. [PMID: 29352997 DOI: 10.1016/j.neuroscience.2018.01.023] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 12/21/2017] [Accepted: 01/09/2018] [Indexed: 12/16/2022]
Abstract
Microglial cells are now recognized as the "gate-keepers" of healthy brain microenvironment with their disrupted functions adversely affecting neurovascular integrity, neuronal homeostasis, and network connectivity. The perception that these cells are purely toxic under neurodegenerative conditions has been challenged by a continuously increasing understanding of their complexity, the existence of a broad array of microglial phenotypes, and their ability to rapidly change in a context-dependent manner to attenuate or exacerbate injuries of different nature. Recent studies have demonstrated that microglial cells exert crucial physiological functions during embryonic and postnatal brain development, some of these functions being unique to particular stages of development, and extending far beyond sensing dangerous signals and serving as antigen presenting cells. In this focused review we cover the roles of microglial cells in regulating embryonic vasculogenesis, neurogenesis, and establishing network connectivity during postnatal brain development. We further discuss context-dependent microglial contribution to neonatal brain injuries associated with prenatal and postnatal infection and inflammation, in relation to neurodevelopmental disorders, as well as perinatal hypoxia-ischemia and arterial focal stroke. We also emphasize microglial phenotypic diversity, notably at the ultrastructural level, and their sex-dependent influence on the pathophysiology of neurodevelopmental disorders.
Collapse
|
40
|
Sierra A, de Castro F, Del Río-Hortega J, Rafael Iglesias-Rozas J, Garrosa M, Kettenmann H. The "Big-Bang" for modern glial biology: Translation and comments on Pío del Río-Hortega 1919 series of papers on microglia. Glia 2018; 64:1801-40. [PMID: 27634048 DOI: 10.1002/glia.23046] [Citation(s) in RCA: 160] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 08/01/2016] [Indexed: 02/06/2023]
Abstract
The word "glia" was coined in the mid-19th century and defined as "the nerve glue". For decades, it was assumed to be a uniform matrix, until cell theorists raised the "neuron doctrine" which stipulated that nervous tissue was composed of individual cells. The term "astrocytes" was introduced in the late 19th century as a synonym for glial cells, but it was Santiago Ramón y Cajal who defined a "third element" distinct from glial cells (astrocytes) and neurons. It was not until 1919 when Pío del Río-Hortega, an alumnus of the Cajal School, introduced the modern terms we use today, and thoroughly described both "oligodendrocytes" and "microglia" to clearly distinguish them from astrocytes. In a series of four papers published that year in Spanish, Río-Hortega described the distribution and morphological phenotype of microglia. He also noted that these cells were the origin of the rod cells described earlier in pathologic tissue, and recognized that resting microglia transformed into an ameboid phenotype in different types of brain diseases and pathologies. He also noted the mesodermal origin of these cells and recognized their phagocytic capacity. We here provide the first English translation of these landmark series of papers, which paved the way for modern glial research. To heighten the value and accessibility of these classic papers and their original figures, an introduction to this critical period of neuroscience is provided, along with unpublished photographs. By adding comments to the translated text, we provide sufficient context so that contemporary scientists may fully appreciate it. GLIA 2016;64:1801-1840.
Collapse
Affiliation(s)
- Amanda Sierra
- Glial Cell Biology Lab, Achucarro Basque Center for Neuroscience, Zamudio, Bizkaia, Spain. .,Ikerbasque Foundation, Bilbao, Bizkaia, Spain. .,Department of Neuroscience, Faculty of Medicine, University of the Basque Country EHU/UPV, Leioa, Bizkaia, Spain.
| | | | - Juan Del Río-Hortega
- Department of Cell Biology, Histology and Pharmacology, Faculty of Medicine, University of Valladolid, Spain
| | | | | | - Helmut Kettenmann
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| |
Collapse
|
41
|
Bilbo S, Stevens B. Microglia: The Brain's First Responders. CEREBRUM : THE DANA FORUM ON BRAIN SCIENCE 2017; 2017:cer-14-17. [PMID: 30210663 PMCID: PMC6132046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
New knowledge about microglia is so fresh that it's not even in the textbooks yet. Microglia are cells that help guide brain development and serve as its immune system helpers by gobbling up diseased or damaged cells and discarding cellular debris. Our authors believe that microglia might hold the key to understanding not just normal brain development, but also what causes Alzheimer's disease, Huntington's disease, autism, schizophrenia, and other intractable brain disorders.
Collapse
|
42
|
|
43
|
Ontogeny and homeostasis of CNS myeloid cells. Nat Immunol 2017; 18:385-392. [PMID: 28323268 DOI: 10.1038/ni.3703] [Citation(s) in RCA: 283] [Impact Index Per Article: 40.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 01/30/2017] [Indexed: 12/12/2022]
Abstract
Myeloid cells in the central nervous system (CNS) represent a heterogeneous class of innate immune cells that contribute to the maintenance of tissue homeostasis differentially during development and adulthood. The subsets of CNS myeloid cells identified so far, including parenchymal microglia and non-parenchymal meningeal, perivascular and choroid-plexus macrophages, as well as disease-associated monocytes, have classically been distinguished on the basis of their surface epitope expression, localization and morphology. However, studies using cell-specific targeting, in vivo imaging, single-cell expression analysis and other sophisticated tools have now increased the depth of knowledge of this immune-cell compartment and call for reevaluation of the traditional views on the origin, fate and function of distinct CNS myeloid subsets. The concepts of CNS macrophage biology that are emerging from these new insights have broad implications for the understanding and treatment of CNS diseases.
Collapse
|
44
|
A polarizing question: do M1 and M2 microglia exist? Nat Neurosci 2017; 19:987-91. [PMID: 27459405 DOI: 10.1038/nn.4338] [Citation(s) in RCA: 1059] [Impact Index Per Article: 151.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 05/14/2016] [Indexed: 12/12/2022]
Abstract
Microglial research has entered a fertile, dynamic phase characterized by novel technologies including two-photon imaging, whole-genome transcriptomic and epigenomic analysis with complementary bioinformatics, unbiased proteomics, cytometry by time of flight (CyTOF; Fluidigm) cytometry, and complex high-content experimental models including slice culture and zebrafish. Against this vivid background of newly emerging data, investigators will encounter in the microglial research literature a body of published work using the terminology of macrophage polarization, most commonly into the M1 and M2 phenotypes. It is the assertion of this opinion piece that microglial polarization has not been established by research findings. Rather, the adoption of this schema was undertaken in an attempt to simplify data interpretation at a time when the ontogeny and functional significance of microglia had not yet been characterized. Now, terminology suggesting established meaningful pathways of microglial polarization hinders rather than aids research progress and should be discarded.
Collapse
|
45
|
Masgrau R, Guaza C, Ransohoff RM, Galea E. Should We Stop Saying 'Glia' and 'Neuroinflammation'? Trends Mol Med 2017; 23:486-500. [PMID: 28499701 DOI: 10.1016/j.molmed.2017.04.005] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Revised: 04/10/2017] [Accepted: 04/11/2017] [Indexed: 12/15/2022]
Abstract
Central nervous system (CNS) therapeutics based on the theoretical framework of neuroinflammation have only barely succeeded. We argue that a problem may be the wrong use of the term 'neuroinflammation' as a distinct nosological entity when, based on recent evidence, it may not explain CNS disease pathology. Indeed, the terms 'neuroinflammation' and 'glia' could be obsolete. First, unbiased molecular profiling of CNS cell populations and individual cells reveals striking phenotypic heterogeneity in health and disease. Second, astrocytes, microglia, oligodendrocytes, and NG2 cells may contribute to higher-brain functions by performing actions beyond housekeeping. We propose that CNS diseases be viewed as failed circuits caused in part by disease-specific dysfunction of cells traditionally called 'glia', and hence, favor therapies promoting their functional recovery.
Collapse
Affiliation(s)
- Roser Masgrau
- Institut de Neurociències and Departament de Bioquímica i Biologia Molecular, Unitat de Bioquímica de Medicina, Universitat Autònoma de Barcelona, 08193 Barcelona, Spain
| | - Carmen Guaza
- Neuroimmunology Group, Functional and Systems Neurobiology Department, Instituto Cajal, Agencia Estatal del Consejo Superior de Investigaciones Científicas, Madrid, España; Spanish Network of Multiple Sclerosis, RETICS, Instituto de Salud Carlos III, Madrid, España
| | | | - Elena Galea
- Institut de Neurociències and Departament de Bioquímica i Biologia Molecular, Unitat de Bioquímica de Medicina, Universitat Autònoma de Barcelona, 08193 Barcelona, Spain; ICREA, Pg. Lluís Companys 23, 08010 Barcelona, Spain.
| |
Collapse
|
46
|
Cerami C, Iaccarino L, Perani D. Molecular Imaging of Neuroinflammation in Neurodegenerative Dementias: The Role of In Vivo PET Imaging. Int J Mol Sci 2017; 18:ijms18050993. [PMID: 28475165 PMCID: PMC5454906 DOI: 10.3390/ijms18050993] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Revised: 04/14/2017] [Accepted: 04/18/2017] [Indexed: 11/16/2022] Open
Abstract
Neurodegeneration elicits neuroinflammatory responses to kill pathogens, clear debris and support tissue repair. Neuroinflammation is a dynamic biological response characterized by the recruitment of innate and adaptive immune system cells in the site of tissue damage. Resident microglia and infiltrating immune cells partake in the restoration of central nervous system homeostasis. Nevertheless, their activation may shift to chronic and aggressive responses, which jeopardize neuron survival and may contribute to the disease process itself. Positron Emission Tomography (PET) molecular imaging represents a unique tool contributing to in vivo investigating of neuroinflammatory processes in patients. In the present review, we first provide an overview on the molecular basis of neuroinflammation in neurodegenerative diseases with emphasis on microglia activation, astrocytosis and the molecular targets for PET imaging. Then, we review the state-of-the-art of in vivo PET imaging for neuroinflammation in dementia conditions associated with different proteinopathies, such as Alzheimer’s disease, frontotemporal lobar degeneration and Parkinsonian spectrum.
Collapse
Affiliation(s)
- Chiara Cerami
- Clinical Neuroscience Department, San Raffaele Turro Hospital, Milan 20121-20162, Italy.
- Division of Neuroscience, San Raffaele Scientific Institute, Milan 20121-20162, Italy.
| | - Leonardo Iaccarino
- Division of Neuroscience, San Raffaele Scientific Institute, Milan 20121-20162, Italy.
- Faculty of Psychology and Molecular Medicine Doctoral Course, Vita-Salute San Raffaele University, Milan 20121-20162, Italy.
| | - Daniela Perani
- Division of Neuroscience, San Raffaele Scientific Institute, Milan 20121-20162, Italy.
- Faculty of Psychology and Molecular Medicine Doctoral Course, Vita-Salute San Raffaele University, Milan 20121-20162, Italy.
- Nuclear Medicine Unit, San Raffaele Hospital, Milan 20121-20162, Italy.
| |
Collapse
|
47
|
Shibata M, Suzuki N. Exploring the role of microglia in cortical spreading depression in neurological disease. J Cereb Blood Flow Metab 2017; 37:1182-1191. [PMID: 28155572 PMCID: PMC5414895 DOI: 10.1177/0271678x17690537] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Microglia play a pivotal role in innate immunity in the brain. During development, they mature from myeloerythroid progenitor cells in the yolk sac and colonize the brain to establish a resident population of tissue macrophages. In the postnatal brain, they exert phagocytosis and induce inflammatory response against invading pathogens. Microglia also act as guardians of brain homeostasis by surveying the microenvironment using motile processes. Cortical spreading depression (CSD) is a slowly propagating (2-5 mm/min) wave of rapid, near-complete depolarization of neurons and astrocytes followed by a period of electrical suppression of a distinct population of cortical neurons. Not only has CSD been implicated in brain migraine aura, but CSD-like events have also been detected in stroke and traumatic injury. CSD causes a considerable perturbation of the ionic environment in the brain, which may be readily detected by microglia. Although CSD is known to activate microglia, the role of microglial activation in CSD-related neurological disorders remains poorly understood. In this article, we first provide an overview of microglial development and the multiple functions of microglia. Then, we review existing data on the relationship between microglia and CSD and discuss the relevance of CSD-induced microglial activation in neurological disease.
Collapse
Affiliation(s)
- Mamoru Shibata
- Department of Neurology, Keio University School of Medicine, Tokyo, Japan
| | - Norihiro Suzuki
- Department of Neurology, Keio University School of Medicine, Tokyo, Japan
| |
Collapse
|
48
|
Song J, Choi SM, Kim BC. Adiponectin Regulates the Polarization and Function of Microglia via PPAR-γ Signaling Under Amyloid β Toxicity. Front Cell Neurosci 2017; 11:64. [PMID: 28326017 PMCID: PMC5339235 DOI: 10.3389/fncel.2017.00064] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 02/23/2017] [Indexed: 12/17/2022] Open
Abstract
Alzheimer’s disease (AD), characterized by the abnormal accumulation of amyloid beta (Aβ), is gradually increasing globally. Given that AD is considered a neuroinflammatory disease, recent studies have focused on the cellular mechanisms in brain inflammatory conditions that underlie AD neuropathology. Microglia are macrophage cells in the central nervous system (CNS) that are activated in response to Aβ condition. The function of microglia contributes to the neuroinflammation in AD brain, suggesting that microglia regulate the production of inflammatory mediators and contribute to the regeneration of damaged tissues. Adiponectin, an adipokine derived from adipose tissue, has been known to regulate inflammation and control macrophages during oxidative stress conditions. In present study, we investigated whether adiponectin influences the polarization and function of microglia under Aβ toxicity by examining alterations of BV2 microglia function and polarization by Acrp30 (a globular form of adiponectin) treatment using reverse transcription PCR, western blotting and immunofluorescence staining. Acrp30 promoted the induction of the M2 phenotype, and regulated the inflammatory responses through peroxisome proliferator-activated receptor (PPAR)-γ signaling under Aβ toxicity. In addition, Acrp30 boosted the capacity of Aβ scavenging in microglia. Taken together, we suggest that adiponectin may control the function of microglia by promoting anti-inflammatory responses through PPAR- γ signaling. Hence, we conclude that adiponectin may act as a critical controller of microglia function in the AD brain.
Collapse
Affiliation(s)
- Juhyun Song
- Department of Biomedical Sciences, Center for Creative Biomedical Scientists at Chonnam National University Gwangju, South Korea
| | - Seong-Min Choi
- Department of Neurology, Chonnam National University Medical School Gwangju, South Korea
| | - Byeong C Kim
- Department of Neurology, Chonnam National University Medical School Gwangju, South Korea
| |
Collapse
|
49
|
Sousa C, Biber K, Michelucci A. Cellular and Molecular Characterization of Microglia: A Unique Immune Cell Population. Front Immunol 2017; 8:198. [PMID: 28303137 PMCID: PMC5332364 DOI: 10.3389/fimmu.2017.00198] [Citation(s) in RCA: 98] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 02/09/2017] [Indexed: 12/26/2022] Open
Abstract
Microglia are essential for the development and function of the adult brain. Microglia arise from erythro-myeloid precursors in the yolk sac and populate the brain rudiment early during development. Unlike monocytes that are constantly renewed from bone marrow hematopoietic stem cells throughout life, resident microglia in the healthy brain persist during adulthood via constant self-renewal. Their ontogeny, together with the absence of turnover from the periphery and the singular environment of the central nervous system, make microglia a unique cell population. Supporting this notion, recent genome-wide transcriptional studies revealed specific gene expression profiles clearly distinct from other brain and peripheral immune cells. Here, we highlight the breakthrough studies that, over the last decades, helped elucidate microglial cell identity, ontogeny, and function. We describe the main techniques that have been used for this task and outline the crucial milestones that have been achieved to reach our actual knowledge of microglia. Furthermore, we give an overview of the “microgliome” that is currently emerging thanks to the constant progress in the modern profiling techniques.
Collapse
Affiliation(s)
- Carole Sousa
- NORLUX Neuro-Oncology Laboratory, Department of Oncology, Luxembourg Institute of Health, Luxembourg, Luxembourg; Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Esch-Belval, Luxembourg
| | - Knut Biber
- Department of Psychiatry and Psychotherapy, Section Molecular Psychiatry, University of Freiburg, Freiburg, Germany; Department of Neuroscience, Section Medical Physiology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Alessandro Michelucci
- NORLUX Neuro-Oncology Laboratory, Department of Oncology, Luxembourg Institute of Health, Luxembourg, Luxembourg; Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Esch-Belval, Luxembourg
| |
Collapse
|
50
|
M1 and M2 Functional Imprinting of Primary Microglia: Role of P2X7 Activation and miR-125b. Mediators Inflamm 2016; 2016:2989548. [PMID: 28090150 PMCID: PMC5206439 DOI: 10.1155/2016/2989548] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Accepted: 11/24/2016] [Indexed: 12/12/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a most frequently occurring and severe form of motor neuron disease, causing death within 3-5 years from diagnosis and with a worldwide incidence of about 2 per 100,000 person-years. Mutations in over twenty genes associated with familial forms of ALS have provided insights into the mechanisms leading to motor neuron death. Moreover, mutations in two RNA binding proteins, TAR DNA binding protein 43 and fused in sarcoma, have raised the intriguing possibility that perturbations of RNA metabolism, including that of the small endogenous RNA molecules that repress target genes at the posttranscriptional level, that is, microRNAs, may contribute to disease pathogenesis. At present, the mechanisms by which microglia actively participate to both toxic and neuroprotective actions in ALS constitute an important matter of research. Among the pathways involved in ALS-altered microglia responses, in previous works we have uncovered the hyperactivation of P2X7 receptor by extracellular ATP and the overexpression of miR-125b, both leading to uncontrolled toxic M1 reactions. In order to shed further light on the complexity of these processes, in this short review we will describe the M1/M2 functional imprinting of primary microglia and a role played by P2X7 and miR-125b in ALS microglia activation.
Collapse
|