1
|
Zhao D, Hu M, Liu S. Glial cells in the mammalian olfactory bulb. Front Cell Neurosci 2024; 18:1426094. [PMID: 39081666 PMCID: PMC11286597 DOI: 10.3389/fncel.2024.1426094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Accepted: 06/24/2024] [Indexed: 08/02/2024] Open
Abstract
The mammalian olfactory bulb (OB), an essential part of the olfactory system, plays a critical role in odor detection and neural processing. Historically, research has predominantly focused on the neuronal components of the OB, often overlooking the vital contributions of glial cells. Recent advancements, however, underscore the significant roles that glial cells play within this intricate neural structure. This review discus the diverse functions and dynamics of glial cells in the mammalian OB, mainly focused on astrocytes, microglia, oligodendrocytes, olfactory ensheathing cells, and radial glia cells. Each type of glial contributes uniquely to the OB's functionality, influencing everything from synaptic modulation and neuronal survival to immune defense and axonal guidance. The review features their roles in maintaining neural health, their involvement in neurodegenerative diseases, and their potential in therapeutic applications for neuroregeneration. By providing a comprehensive overview of glial cell types, their mechanisms, and interactions within the OB, this article aims to enhance our understanding of the olfactory system's complexity and the pivotal roles glial cells play in both health and disease.
Collapse
Affiliation(s)
| | | | - Shaolin Liu
- Isakson Center for Neurological Disease Research, Department of Physiology and Pharmacology, Department of Biomedical Sciences, University of Georgia College of Veterinary Medicine, Athens, GA, United States
| |
Collapse
|
2
|
Mehl LC, Manjally AV, Bouadi O, Gibson EM, Tay TL. Microglia in brain development and regeneration. Development 2022; 149:275253. [PMID: 35502782 PMCID: PMC9124570 DOI: 10.1242/dev.200425] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
It has recently emerged that microglia, the tissue-resident macrophages of the central nervous system, play significant non-innate immune roles to support the development, maintenance, homeostasis and repair of the brain. Apart from being highly specialized brain phagocytes, microglia modulate the development and functions of neurons and glial cells through both direct and indirect interactions. Thus, recognizing the elements that influence the homeostasis and heterogeneity of microglia in normal brain development is crucial to understanding the mechanisms that lead to early disease pathogenesis of neurodevelopmental disorders. In this Review, we discuss recent studies that have elucidated the physiological development of microglia and summarize our knowledge of their non-innate immune functions in brain development and tissue repair.
Collapse
Affiliation(s)
- Lindsey C Mehl
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Palo Alto, CA 94305, USA
| | | | - Ouzéna Bouadi
- Faculty of Biology, University of Freiburg, Freiburg, 79104, Germany
| | - Erin M Gibson
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Palo Alto, CA 94305, USA
| | - Tuan L Tay
- Faculty of Biology, University of Freiburg, Freiburg, 79104, Germany.,BrainLinks-BrainTools Centre, University of Freiburg, Freiburg, 79110, Germany.,Freiburg Institute of Advanced Studies, University of Freiburg, Freiburg, 79104, Germany
| |
Collapse
|
3
|
Sharma R, Mei A, Mathew V, Kashpur O, Wallingford MC. Interaction of extraembryonic microglia and neonatal brain development. Exp Neurol 2022; 351:113986. [DOI: 10.1016/j.expneurol.2022.113986] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 12/22/2021] [Accepted: 01/13/2022] [Indexed: 11/29/2022]
|
4
|
Rayasam A, Fukuzaki Y, Vexler ZS. Microglia-leucocyte axis in cerebral ischaemia and inflammation in the developing brain. Acta Physiol (Oxf) 2021; 233:e13674. [PMID: 33991400 DOI: 10.1111/apha.13674] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 05/06/2021] [Accepted: 05/08/2021] [Indexed: 12/13/2022]
Abstract
Development of the Central Nervous System (CNS) is reliant on the proper function of numerous intricately orchestrated mechanisms that mature independently, including constant communication between the CNS and the peripheral immune system. This review summarizes experimental knowledge of how cerebral ischaemia in infants and children alters physiological communication between leucocytes, brain immune cells, microglia and the neurovascular unit (NVU)-the "microglia-leucocyte axis"-and contributes to acute and long-term brain injury. We outline physiological development of CNS barriers in relation to microglial and leucocyte maturation and the plethora of mechanisms by which microglia and peripheral leucocytes communicate during postnatal period, including receptor-mediated and intracellular inflammatory signalling, lipids, soluble factors and extracellular vesicles. We focus on the "microglia-leucocyte axis" in rodent models of most common ischaemic brain diseases in the at-term infants, hypoxic-ischaemic encephalopathy (HIE) and focal arterial stroke and discuss commonalities and distinctions of immune-neurovascular mechanisms in neonatal and childhood stroke compared to stroke in adults. Given that hypoxic and ischaemic brain damage involve Toll-like receptor (TLR) activation, we discuss the modulatory role of viral and bacterial TLR2/3/4-mediated infection in HIE, perinatal and childhood stroke. Furthermore, we provide perspective of the dynamics and contribution of the axis in cerebral ischaemia depending on the CNS maturational stage at the time of insult, and modulation independently and in consort by individual axis components and in a sex dependent ways. Improved understanding on how to modify crosstalk between microglia and leucocytes will aid in developing age-appropriate therapies for infants and children who suffered cerebral ischaemia.
Collapse
Affiliation(s)
- Aditya Rayasam
- Department of Neurology University of California San Francisco San Francisco CA USA
| | - Yumi Fukuzaki
- Department of Neurology University of California San Francisco San Francisco CA USA
| | - Zinaida S. Vexler
- Department of Neurology University of California San Francisco San Francisco CA USA
| |
Collapse
|
5
|
Hanger B, Couch A, Rajendran L, Srivastava DP, Vernon AC. Emerging Developments in Human Induced Pluripotent Stem Cell-Derived Microglia: Implications for Modelling Psychiatric Disorders With a Neurodevelopmental Origin. Front Psychiatry 2020; 11:789. [PMID: 32848951 PMCID: PMC7433763 DOI: 10.3389/fpsyt.2020.00789] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 07/23/2020] [Indexed: 12/15/2022] Open
Abstract
Microglia, the resident tissue macrophages of the brain, are increasingly implicated in the pathophysiology of psychiatric disorders with a neurodevelopmental origin, including schizophrenia. To date, however, our understanding of the potential role for these cells in schizophrenia has been informed by studies of aged post-mortem samples, low resolution in vivo neuroimaging and rodent models. Whilst these have provided important insights, including signs of the heterogeneous nature of microglia, we currently lack a validated human in vitro system to characterize microglia in the context of brain health and disease during neurodevelopment. Primarily, this reflects a lack of access to human primary tissue during developmental stages. In this review, we first describe microglia, including their ontogeny and heterogeneity and consider their role in brain development. We then provide an evaluation of the potential for differentiating microglia from human induced pluripotent stem cells (hiPSCs) as a robust in vitro human model system to study these cells. We find the majority of protocols for hiPSC-derived microglia generate cells characteristically similar to foetal stage microglia when exposed to neuronal environment-like cues. This may represent a robust and relevant model for the study of cellular and molecular mechanisms in schizophrenia. Each protocol however, provides unique benefits as well as shortcomings, highlighting the need for context-dependent protocol choice and cross-lab collaboration and communication to identify the most robust and translatable microglia model.
Collapse
Affiliation(s)
- Bjørn Hanger
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, Maurice Wohl Clinical Neuroscience Institute, King’s College London, London, United Kingdom
| | - Amalie Couch
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, Maurice Wohl Clinical Neuroscience Institute, King’s College London, London, United Kingdom
| | - Lawrence Rajendran
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, Maurice Wohl Clinical Neuroscience Institute, King’s College London, London, United Kingdom
- UK Dementia Research Institute, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, United Kingdom
| | - Deepak P. Srivastava
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, Maurice Wohl Clinical Neuroscience Institute, King’s College London, London, United Kingdom
- MRC Centre for Neurodevelopmental Disorders, King’s College London, London, United Kingdom
| | - Anthony C. Vernon
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, Maurice Wohl Clinical Neuroscience Institute, King’s College London, London, United Kingdom
- MRC Centre for Neurodevelopmental Disorders, King’s College London, London, United Kingdom
| |
Collapse
|
6
|
Min Y, Yan L, Wang Q, Wang F, Hua H, Yuan Y, Jin H, Zhang M, Zhao Y, Yang J, Jiang X, Yang Y, Li F. Distinct Residential and Infiltrated Macrophage Populations and Their Phagocytic Function in Mild and Severe Neonatal Hypoxic-Ischemic Brain Damage. Front Cell Neurosci 2020; 14:244. [PMID: 32903800 PMCID: PMC7438904 DOI: 10.3389/fncel.2020.00244] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 07/15/2020] [Indexed: 01/10/2023] Open
Abstract
Neonatal brain injury, especially severe injury induced by hypoxia-ischemia (HI), causes mortality and long-term neurological impairments. Our previous study demonstrated activation of CD11b+ myeloid cells, including residential microglial cells (MGs) and infiltrating monocyte-derived macrophages (MDMs) in a murine model of hypoxic-ischemic brain damage (HIBD), with unknown functions. Here, we study the differences in the phagocytic function of MGs and MDMs to clarify their potential roles after HIBD. HI was induced in 9-10-day postnatal mice. On days 1 and 3 after injury, pathological and neurobehavioral tests were performed to categorize the brain damage as mild or severe. Flow cytometry was applied to quantify the dynamic change in the numbers of MGs and MDMs according to the relative expression level of CD45 in CD11b+ cells. CX3CR1 GFPCCR2 RFP double-transformed mice were used to identify MGs and MDMs in the brain parenchyma after HIBD. Lysosome-associated membrane protein 1 (LAMP1), toll-like receptor 2 (TLR2), CD36, and transforming growth factor (TGF-β) expression levels were measured to assess the underlying function of phagocytes and neuroprotective factors in these cells. The FITC-dextran 40 phagocytosis assay was applied to examine the change in phagocytic function under oxygen-glucose deprivation (OGD) in vitro. We found that neonatal HI induced a different degree of brain damage: mild or severe injury. Compared with mildly injured animals, mice with severe injury had lower weight, worse neurobehavioral scores, and abnormal brain morphology. In a severely injured brain, CD11b+ cells remarkably increased, including an increase in the MDM population and a decrease in the MG population. Furthermore, MDM infiltration into the brain parenchyma was evident in CX3CR1 GFPCCR2 RFP double-transformed mice. Mild and severe brain injury caused different phagocytosis-related responses and neuroprotective functions of MDMs and MGs at 1 and 3 days following HI. The phagocytic function was activated in BV2 cells but downregulated in Raw264.7 cells under OGD in vitro. These observations indicate that neonatal HI induced different degrees of brain injury. The proportion of infiltrated macrophage MDMs was increased and they were recruited into the injured brain parenchyma in severe brain injury. The resident macrophage MGs proportion decreased and maintained activated phagocytic function in both mild and severe brain injury, and restored neuroprotective function in severe brain injury.
Collapse
Affiliation(s)
- Yingjun Min
- Department of Pathology and Pathophysiology, School of Basic Medical Sciences, Kunming Medical University, Kunming, China
| | - Lin Yan
- Department of Pathology and Pathophysiology, School of Basic Medical Sciences, Kunming Medical University, Kunming, China
| | - Qian Wang
- Department of Pathology and Pathophysiology, School of Basic Medical Sciences, Kunming Medical University, Kunming, China
| | - Fang Wang
- Department of Pathology and Pathophysiology, School of Basic Medical Sciences, Kunming Medical University, Kunming, China
| | - Hairong Hua
- Department of Pathology and Pathophysiology, School of Basic Medical Sciences, Kunming Medical University, Kunming, China
| | - Yun Yuan
- Department of Human Anatomy and Histoembryology, School of Basic Medical Sciences, Kunming Medical University, Kunming, China
| | - Huiyan Jin
- Department of Functional Experiment, School of Basic Medical Sciences, Kunming Medical University, Kunming, China
| | - Ming Zhang
- Yunnan Key Laboratory of Stem Cell and Regenerative Medicine, Institute of Molecular and Clinical Medicine, Kunming Medical University, Kunming, China
| | - Yaling Zhao
- Department of Obstetrics and Gynecology, First Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Jianzhong Yang
- Department of Psychiatry, The Second Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Xiangning Jiang
- Department of Neurology, University of California, San Francisco, San Francisco, CA, United States
| | - Yuan Yang
- Department of Physiology, School of Basic Medical Sciences, Kunming Medical University, Kunming, China
| | - Fan Li
- Department of Pathology and Pathophysiology, School of Basic Medical Sciences, Kunming Medical University, Kunming, China
| |
Collapse
|
7
|
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
|
8
|
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: 321] [Impact Index Per Article: 64.2] [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
|
9
|
Konishi H, Kiyama H, Ueno M. Dual functions of microglia in the formation and refinement of neural circuits during development. Int J Dev Neurosci 2018; 77:18-25. [DOI: 10.1016/j.ijdevneu.2018.09.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 09/20/2018] [Accepted: 09/30/2018] [Indexed: 12/29/2022] Open
Affiliation(s)
- Hiroyuki Konishi
- Department of Functional Anatomy and NeuroscienceNagoya University Graduate School of MedicineNagoya466‐8550Japan
| | - Hiroshi Kiyama
- Department of Functional Anatomy and NeuroscienceNagoya University Graduate School of MedicineNagoya466‐8550Japan
| | - Masaki Ueno
- Department of System Pathology for Neurological DisordersBrain Research InstituteNiigata UniversityNiigata951‐8585Japan
| |
Collapse
|
10
|
Menassa DA, Gomez-Nicola D. Microglial Dynamics During Human Brain Development. Front Immunol 2018; 9:1014. [PMID: 29881376 PMCID: PMC5976733 DOI: 10.3389/fimmu.2018.01014] [Citation(s) in RCA: 124] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2018] [Accepted: 04/23/2018] [Indexed: 11/13/2022] Open
Abstract
Microglial cells are thought to colonize the human cerebrum between the 4th and 24th gestational weeks. Rodent studies have demonstrated that these cells originate from yolk sac progenitors though it is not clear whether this directly pertains to human development. Our understanding of microglial cell dynamics in the developing human brain comes mostly from postmortem studies demonstrating that the beginning of microglial colonization precedes the appearance of the vasculature, the blood–brain barrier, astrogliogenesis, oligodendrogenesis, neurogenesis, migration, and myelination of the various brain areas. Furthermore, migrating microglial populations cluster by morphology and express differential markers within the developing brain and according to developmental age. With the advent of novel technologies such as RNA-sequencing in fresh human tissue, we are beginning to identify the molecular features of the adult microglial signature. However, this is may not extend to the much more dynamic and rapidly changing antenatal microglial population and this is further complicated by the scarcity of tissue resources. In this brief review, we first describe the various historic schools of thought that had debated the origin of microglial cells while examining the evidence supporting the various theories. We then proceed to examine the evidence we have accumulated on microglial dynamics in the developing human brain, present evidence from rodent studies on the functional role of microglia during development and finally identify limitations for the used approaches in human studies and highlight under investigated questions.
Collapse
Affiliation(s)
- David A Menassa
- Biological Sciences, Faculty of Natural and Environmental Sciences, Southampton General Hospital, University of Southampton, Southampton, United Kingdom
| | - Diego Gomez-Nicola
- Biological Sciences, Faculty of Natural and Environmental Sciences, Southampton General Hospital, University of Southampton, Southampton, United Kingdom
| |
Collapse
|
11
|
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
|
12
|
Tay TL, Béchade C, D'Andrea I, St-Pierre MK, Henry MS, Roumier A, Tremblay ME. Microglia Gone Rogue: Impacts on Psychiatric Disorders across the Lifespan. Front Mol Neurosci 2018; 10:421. [PMID: 29354029 PMCID: PMC5758507 DOI: 10.3389/fnmol.2017.00421] [Citation(s) in RCA: 138] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Accepted: 12/04/2017] [Indexed: 12/21/2022] Open
Abstract
Microglia are the predominant immune response cells and professional phagocytes of the central nervous system (CNS) that have been shown to be important for brain development and homeostasis. These cells present a broad spectrum of phenotypes across stages of the lifespan and especially in CNS diseases. Their prevalence in all neurological pathologies makes it pertinent to reexamine their distinct roles during steady-state and disease conditions. A major question in the field is determining whether the clustering and phenotypical transformation of microglial cells are leading causes of pathogenesis, or potentially neuroprotective responses to the onset of disease. The recent explosive growth in our understanding of the origin and homeostasis of microglia, uncovering their roles in shaping of the neural circuitry and synaptic plasticity, allows us to discuss their emerging functions in the contexts of cognitive control and psychiatric disorders. The distinct mesodermal origin and genetic signature of microglia in contrast to other neuroglial cells also make them an interesting target for the development of therapeutics. Here, we review the physiological roles of microglia, their contribution to the effects of environmental risk factors (e.g., maternal infection, early-life stress, dietary imbalance), and their impact on psychiatric disorders initiated during development (e.g., Nasu-Hakola disease (NHD), hereditary diffuse leukoencephaly with spheroids, Rett syndrome, autism spectrum disorders (ASDs), and obsessive-compulsive disorder (OCD)) or adulthood (e.g., alcohol and drug abuse, major depressive disorder (MDD), bipolar disorder (BD), schizophrenia, eating disorders and sleep disorders). Furthermore, we discuss the changes in microglial functions in the context of cognitive aging, and review their implication in neurodegenerative diseases of the aged adult (e.g., Alzheimer’s and Parkinson’s). Taking into account the recent identification of microglia-specific markers, and the availability of compounds that target these cells selectively in vivo, we consider the prospect of disease intervention via the microglial route.
Collapse
Affiliation(s)
- Tuan Leng Tay
- Institute of Neuropathology, University of Freiburg, Freiburg, Germany.,Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Catherine Béchade
- INSERM UMR-S 839, Paris, France.,Sorbonne Universités, Université Pierre et Marie Curie (UPMC), Paris, France.,Institut du Fer à Moulin, Paris, France
| | - Ivana D'Andrea
- INSERM UMR-S 839, Paris, France.,Sorbonne Universités, Université Pierre et Marie Curie (UPMC), Paris, France.,Institut du Fer à Moulin, Paris, France
| | | | - Mathilde S Henry
- Axe Neurosciences, CRCHU de Québec-Université Laval, Québec, QC, Canada
| | - Anne Roumier
- INSERM UMR-S 839, Paris, France.,Sorbonne Universités, Université Pierre et Marie Curie (UPMC), Paris, France.,Institut du Fer à Moulin, Paris, France
| | - Marie-Eve Tremblay
- Axe Neurosciences, CRCHU de Québec-Université Laval, Québec, QC, Canada.,Département de Médecine Moléculaire, Université Laval, Québec, QC, Canada
| |
Collapse
|
13
|
Mildner A, Huang H, Radke J, Stenzel W, Priller J. P2Y12receptor is expressed on human microglia under physiological conditions throughout development and is sensitive to neuroinflammatory diseases. Glia 2016; 65:375-387. [DOI: 10.1002/glia.23097] [Citation(s) in RCA: 164] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 10/18/2016] [Accepted: 10/24/2016] [Indexed: 01/01/2023]
Affiliation(s)
- Alexander Mildner
- Department of Neuropsychiatry and Laboratory of Molecular Psychiatry; Charité-Universitätsmedizin Berlin; Berlin 10117 Germany
| | - Hao Huang
- Department of Neuropsychiatry and Laboratory of Molecular Psychiatry; Charité-Universitätsmedizin Berlin; Berlin 10117 Germany
| | - Josefine Radke
- Department of Neuropathology; Charité-Universitätsmedizin Berlin; Berlin 10117 Germany
- Berlin Institute of Health (BIH); Berlin Germany
- German Consortium for Translational Cancer Research (DKTK); Heidelberg Germany
| | - Werner Stenzel
- Department of Neuropathology; Charité-Universitätsmedizin Berlin; Berlin 10117 Germany
| | - Josef Priller
- Department of Neuropsychiatry and Laboratory of Molecular Psychiatry; Charité-Universitätsmedizin Berlin; Berlin 10117 Germany
- Berlin Institute of Health (BIH); Berlin Germany
- Cluster of Excellence NeuroCure and DZNE; Berlin 10117 Germany
| |
Collapse
|
14
|
Tay TL, Savage JC, Hui CW, Bisht K, Tremblay MÈ. Microglia across the lifespan: from origin to function in brain development, plasticity and cognition. J Physiol 2016; 595:1929-1945. [PMID: 27104646 DOI: 10.1113/jp272134] [Citation(s) in RCA: 352] [Impact Index Per Article: 44.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Accepted: 03/15/2016] [Indexed: 12/11/2022] Open
Abstract
Microglia are the only immune cells that permanently reside in the central nervous system (CNS) alongside neurons and other types of glial cells. The past decade has witnessed a revolution in our understanding of their roles during normal physiological conditions. Cutting-edge techniques revealed that these resident immune cells are critical for proper brain development, actively maintain health in the mature brain, and rapidly adapt their function to physiological or pathophysiological needs. In this review, we highlight recent studies on microglial origin (from the embryonic yolk sac) and the factors regulating their differentiation and homeostasis upon brain invasion. Elegant experiments tracking microglia in the CNS allowed studies of their unique roles compared with other types of resident macrophages. Here we review the emerging roles of microglia in brain development, plasticity and cognition, and discuss the implications of the depletion or dysfunction of microglia for our understanding of disease pathogenesis. Immune activation, inflammation and various other conditions resulting in undesirable microglial activity at different stages of life could severely impair learning, memory and other essential cognitive functions. The diversity of microglial phenotypes across the lifespan, between compartments of the CNS, and sexes, as well as their crosstalk with the body and external environment, is also emphasised. Understanding what defines particular microglial phenotypes is of major importance for future development of innovative therapies controlling their effector functions, with consequences for cognition across chronic stress, ageing, neuropsychiatric and neurological diseases.
Collapse
Affiliation(s)
- Tuan Leng Tay
- Institute of Neuropathology, University of Freiburg, Germany
| | - Julie C Savage
- Axe Neurosciences, Centre de recherche du CHU de Québec, Québec, Canada
| | - Chin Wai Hui
- Axe Neurosciences, Centre de recherche du CHU de Québec, Québec, Canada
| | - Kanchan Bisht
- Axe Neurosciences, Centre de recherche du CHU de Québec, Québec, Canada
| | | |
Collapse
|
15
|
Tay TL, Hagemeyer N, Prinz M. The force awakens: insights into the origin and formation of microglia. Curr Opin Neurobiol 2016; 39:30-7. [PMID: 27107946 DOI: 10.1016/j.conb.2016.04.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2015] [Revised: 04/05/2016] [Accepted: 04/06/2016] [Indexed: 12/12/2022]
Abstract
Microglia are tissue resident macrophages of the central nervous system (CNS) that maintain homeostasis and respond to immune challenges. New genetic fate mapping tools have revealed a yolk sac origin of microglia. Once established in the CNS, microglia persist throughout the lifetime of the organism behind the blood-brain barrier and maintain themselves by self-renewal. Recent studies uncovered a broad spectrum of microglial functions that are influenced by the dynamism of brain formation and neuronal wiring. This review focuses on current findings concerning microglia origin and formation during development and discusses the factors important for microglia survival and function.
Collapse
Affiliation(s)
- Tuan Leng Tay
- Institute of Neuropathology, University of Freiburg, Germany
| | - Nora Hagemeyer
- Institute of Neuropathology, University of Freiburg, Germany
| | - Marco Prinz
- Institute of Neuropathology, University of Freiburg, Germany; BIOSS Centre for Biological Signaling Studies, University of Freiburg, Germany.
| |
Collapse
|