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Davies MR, Greenberg Z, van Vuurden DG, Cross CB, Zannettino ACW, Bardy C, Wardill HR. More than a small adult brain: Lessons from chemotherapy-induced cognitive impairment for modelling paediatric brain disorders. Brain Behav Immun 2024; 115:229-247. [PMID: 37858741 DOI: 10.1016/j.bbi.2023.10.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 10/10/2023] [Accepted: 10/14/2023] [Indexed: 10/21/2023] Open
Abstract
Childhood is recognised as a period of immense physical and emotional development, and this, in part, is driven by underlying neurophysiological transformations. These neurodevelopmental processes are unique to the paediatric brain and are facilitated by augmented rates of neuroplasticity and expanded neural stem cell populations within neurogenic niches. However, given the immaturity of the developing central nervous system, innate protective mechanisms such as neuroimmune and antioxidant responses are functionally naïve which results in periods of heightened sensitivity to neurotoxic insult. This is highly relevant in the context of paediatric cancer, and in particular, the neurocognitive symptoms associated with treatment, such as surgery, radio- and chemotherapy. The vulnerability of the developing brain may increase susceptibility to damage and persistent symptomology, aligning with reports of more severe neurocognitive dysfunction in children compared to adults. It is therefore surprising, given this intensified neurocognitive burden, that most of the pre-clinical, mechanistic research focuses exclusively on adult populations and extrapolates findings to paediatric cohorts. Given this dearth of age-specific research, throughout this review we will draw comparisons with neurodevelopmental disorders which share comparable pathways to cancer treatment related side-effects. Furthermore, we will examine the unique nuances of the paediatric brain along with the somatic systems which influence neurological function. In doing so, we will highlight the importance of developing in vitro and in vivo paediatric disease models to produce age-specific discovery and clinically translatable research.
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Affiliation(s)
- Maya R Davies
- School of Biomedicine, Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide, SA, Australia; Supportive Oncology Research Group, Precision Cancer Medicine Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA, Australia.
| | - Zarina Greenberg
- South Australian Health and Medical Research Institute (SAHMRI), Laboratory of Human Neurophysiology and Genetics, Adelaide, SA, Australia
| | - Dannis G van Vuurden
- Princess Máxima Center for Pediatric Oncology, Heidelberglaan 25, 3584 CS Utrecht, the weNetherlands
| | - Courtney B Cross
- Supportive Oncology Research Group, Precision Cancer Medicine Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA, Australia
| | - Andrew C W Zannettino
- School of Biomedicine, Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide, SA, Australia
| | - Cedric Bardy
- South Australian Health and Medical Research Institute (SAHMRI), Laboratory of Human Neurophysiology and Genetics, Adelaide, SA, Australia; Flinders Health and Medical Research Institute, College of Medicine and Public Health, Flinders University, Adelaide, SA, Australia
| | - Hannah R Wardill
- School of Biomedicine, Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide, SA, Australia; Supportive Oncology Research Group, Precision Cancer Medicine Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA, Australia
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Castillo-Ruiz A, Gars A, Sturgeon H, Ronczkowski NM, Pyaram DN, Dauriat CJG, Chassaing B, Forger NG. Brain effects of gestating germ-free persist in mouse neonates despite acquisition of a microbiota at birth. Front Neurosci 2023; 17:1130347. [PMID: 37207179 PMCID: PMC10188942 DOI: 10.3389/fnins.2023.1130347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 04/10/2023] [Indexed: 05/21/2023] Open
Abstract
At birth, mammals experience a massive colonization by microorganisms. We previously reported that newborn mice gestated and born germ-free (GF) have increased microglial labeling and alterations in developmental neuronal cell death in the hippocampus and hypothalamus, as well as greater forebrain volume and body weight when compared to conventionally colonized (CC) mice. To test whether these effects are solely due to differences in postnatal microbial exposure, or instead may be programmed in utero, we cross-fostered GF newborns immediately after birth to CC dams (GF→CC) and compared them to offspring fostered within the same microbiota status (CC→CC, GF→GF). Because key developmental events (including microglial colonization and neuronal cell death) shape the brain during the first postnatal week, we collected brains on postnatal day (P) 7. To track gut bacterial colonization, colonic content was also collected and subjected to 16S rRNA qPCR and Illumina sequencing. In the brains of GF→GF mice, we replicated most of the effects seen previously in GF mice. Interestingly, the GF brain phenotype persisted in GF→CC offspring for almost all measures. In contrast, total bacterial load did not differ between the CC→CC and GF→CC groups on P7, and bacterial community composition was also very similar, with a few exceptions. Thus, GF→CC offspring had altered brain development during at least the first 7 days after birth despite a largely normal microbiota. This suggests that prenatal influences of gestating in an altered microbial environment programs neonatal brain development.
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Affiliation(s)
- Alexandra Castillo-Ruiz
- Neuroscience Institute, Georgia State University, Atlanta, GA, United States
- *Correspondence: Alexandra Castillo-Ruiz,
| | - Aviva Gars
- Neuroscience Institute, Georgia State University, Atlanta, GA, United States
| | - Hannah Sturgeon
- Neuroscience Institute, Georgia State University, Atlanta, GA, United States
| | | | - Dhanya N. Pyaram
- Neuroscience Institute, Georgia State University, Atlanta, GA, United States
| | - Charlène J. G. Dauriat
- INSERM U1016, Team “Mucosal Microbiota in Chronic Inflammatory Diseases,” Université Paris Cité, Paris, France
| | - Benoit Chassaing
- INSERM U1016, Team “Mucosal Microbiota in Chronic Inflammatory Diseases,” Université Paris Cité, Paris, France
| | - Nancy G. Forger
- Neuroscience Institute, Georgia State University, Atlanta, GA, United States
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Ren Y, Zhou Y, You Z, Deng H, Kem WR, Mao J, Zhang W, Martyn JJ. The nonopioid cholinergic agonist GTS-21 mitigates morphine-induced aggravation of burn injury pain together with inhibition of spinal microglia activation in young rats. Br J Anaesth 2022. [DOI: 10.1016/j.bja.2022.07.055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 07/06/2022] [Accepted: 07/12/2022] [Indexed: 11/20/2022] Open
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Ngwa C, Qi S, Mamun AA, Xu Y, Sharmeen R, Liu F. Age and sex differences in primary microglia culture: A comparative study. J Neurosci Methods 2021; 364:109359. [PMID: 34537225 DOI: 10.1016/j.jneumeth.2021.109359] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 08/27/2021] [Accepted: 09/13/2021] [Indexed: 01/02/2023]
Abstract
BACKGROUND Microglia play a central role in neuroinflammation in various CNS diseases.Neonatal microglial culture has been extensively used to in vitro study microglial activation; however, as many neuroinflammatory diseases occur in the elderly, the neonatal microglial culture may not fully replicate the aged microglial activity seen in these diseases. NEW METHOD Primary microglia from both 18-24-month-old and P0-P4 C57BL/6 mice were cultured simultaneously. Morphology and activation profiles of the two age groups of microglia were examined following ischemic stimulation, by ELISA, RT-PCR, live microscopy, immunocytochemistry, and Western blotting. RESULTS We showed that aged microglia had larger cell bodies, more cytoplasmic inclusions, and enhanced phagocytosis than neonatal microglia. Cytokine production in these cells exhibited heterogeneity either after or before ischemic stimulation. The baseline expression of microglial marker CD11b was significantly higher in aged vs. neonatal cells; ischemic stimulation increased the expression in neonatal vs. aged microglia only in males but not in females. COMPARISON WITH EXISTING METHODS Previous primary microglia cultures have been limited to using neonatal/adult cells. This method is complementary to exiting methods and works for aged microglia, and does not suffer from potential limitations due to filtering artifacts. The protocol renders microglial culture no need for meningeal/hippocampal removal prior to brain tissue dissociation, and compares microglia between males vs. females, and between the aged vs. neonates. CONCLUSIONS We concluded that neonatal microglial culture is not appropriate for those in vitro studies that mimic the neuroinflammatory central nervous system disorders occurring in the elderly, in which case the aged microglial culture should be applied, and sex differences should be considered.
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Affiliation(s)
- Conelius Ngwa
- Department of Neurology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Shaohua Qi
- Department of Neurology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Abdullah Al Mamun
- Department of Neurology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Yan Xu
- Department of Neurology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Romana Sharmeen
- Department of Neurology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Fudong Liu
- Department of Neurology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA.
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Delahaye-Duriez A, Dufour A, Bokobza C, Gressens P, Van Steenwinckel J. Targeting Microglial Disturbances to Protect the Brain From Neurodevelopmental Disorders Associated With Prematurity. J Neuropathol Exp Neurol 2021; 80:634-648. [PMID: 34363661 DOI: 10.1093/jnen/nlab049] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Microglial activation during critical phases of brain development can result in short- and long-term consequences for neurological and psychiatric health. Several studies in humans and rodents have shown that microglial activation, leading to a transition from the homeostatic state toward a proinflammatory phenotype, has adverse effects on the developing brain and neurodevelopmental disorders. Targeting proinflammatory microglia may be an effective strategy for protecting the brain and attenuating neurodevelopmental disorders induced by inflammation. In this review we focus on the role of inflammation and the activation of immature microglia (pre-microglia) soon after birth in prematurity-associated neurodevelopmental disorders, and the specific features of pre-microglia during development. We also highlight the relevance of immunomodulatory strategies for regulating activated microglia in a rodent model of perinatal brain injury. An original neuroprotective approach involving a nanoparticle-based therapy and targeting microglia, with the aim of improving myelination and protecting the developing brain, is also addressed.
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Affiliation(s)
- Andrée Delahaye-Duriez
- From the NeuroDiderot, UMR 1141, Inserm, Université de Paris, Paris, France.,UFR SMBH, Université Sorbonne Paris Nord, Bobigny, France.,Assistance Publique des Hôpitaux de Paris, Hôpital Jean Verdier, Service d'Histologie-Embryologie-Cytogénétique, Bondy, France
| | - Adrien Dufour
- From the NeuroDiderot, UMR 1141, Inserm, Université de Paris, Paris, France
| | - Cindy Bokobza
- From the NeuroDiderot, UMR 1141, Inserm, Université de Paris, Paris, France
| | - Pierre Gressens
- From the NeuroDiderot, UMR 1141, Inserm, Université de Paris, Paris, France
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Pietrowski MJ, Gabr AA, Kozlov S, Blum D, Halle A, Carvalho K. Glial Purinergic Signaling in Neurodegeneration. Front Neurol 2021; 12:654850. [PMID: 34054698 PMCID: PMC8160300 DOI: 10.3389/fneur.2021.654850] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Accepted: 04/16/2021] [Indexed: 12/15/2022] Open
Abstract
Purinergic signaling regulates neuronal and glial cell functions in the healthy CNS. In neurodegenerative diseases, purinergic signaling becomes dysregulated and can affect disease-associated phenotypes of glial cells. In this review, we discuss how cell-specific expression patterns of purinergic signaling components change in neurodegeneration and how dysregulated glial purinergic signaling and crosstalk may contribute to disease pathophysiology, thus bearing promising potential for the development of new therapeutical options for neurodegenerative diseases.
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Affiliation(s)
- Marie J Pietrowski
- Microglia and Neuroinflammation Laboratory, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Amr Ahmed Gabr
- Microglia and Neuroinflammation Laboratory, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany.,Department of Physiology, Faculty of Veterinary Medicine, Cairo University, Giza, Egypt
| | - Stanislav Kozlov
- Microglia and Neuroinflammation Laboratory, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - David Blum
- University of Lille, Inserm, CHU Lille, U1172 LilNCog - Lille Neuroscience and Cognition, Lille, France.,Alzheimer and Tauopathies, Labex DISTALZ, Lille, France
| | - Annett Halle
- Microglia and Neuroinflammation Laboratory, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany.,Institute of Neuropathology, University of Bonn, Bonn, Germany
| | - Kevin Carvalho
- University of Lille, Inserm, CHU Lille, U1172 LilNCog - Lille Neuroscience and Cognition, Lille, France.,Alzheimer and Tauopathies, Labex DISTALZ, Lille, France
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Jesudasan SJB, Gupta SJ, Churchward MA, Todd KG, Winship IR. Inflammatory Cytokine Profile and Plasticity of Brain and Spinal Microglia in Response to ATP and Glutamate. Front Cell Neurosci 2021; 15:634020. [PMID: 33889075 PMCID: PMC8057348 DOI: 10.3389/fncel.2021.634020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 03/10/2021] [Indexed: 11/27/2022] Open
Abstract
Microglia are the primary cells in the central nervous system that identify and respond to injury or damage. Such a perturbation in the nervous system induces the release of molecules including ATP and glutamate that act as damage-associated molecular patterns (DAMPs). DAMPs are detected by microglia, which then regulate the inflammatory response in a manner sensitive to their surrounding environment. The available data indicates that ATP and glutamate can induce the release of pro inflammatory factors TNF (tumor necrosis factor), IL-1β (interleukin 1 beta), and NO (nitric oxide) from microglia. However, non-physiological concentrations of ATP and glutamate were often used to derive these insights. Here, we have compared the response of spinal cord microglia (SM) relative to brain microglia (BM) using physiologically relevant concentrations of glutamate and ATP that mimic injured conditions in the central nervous system. The data show that ATP and glutamate are not significant modulators of the release of cytokines from either BM or SM. Consistent with previous studies, spinal microglia exhibited a general trend toward reduced release of inflammatory cytokines relative to brain-derived microglia. Moreover, we demonstrate that the responses of microglia to these DAMPs can be altered by modifying the biochemical milieu in their surrounding environment. Preconditioning brain derived microglia with media from spinal cord derived mixed glial cultures shifted their release of IL-1ß and IL-6 to a less inflammatory phenotype consistent with spinal microglia.
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Affiliation(s)
- Sam Joshva Baskar Jesudasan
- Neurochemical Research Unit, Department of Psychiatry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
| | - Somnath J. Gupta
- Neurochemical Research Unit, Department of Psychiatry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
| | - Matthew A. Churchward
- Neurochemical Research Unit, Department of Psychiatry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
- Department of Biology and Environmental Sciences, Concordia University of Edmonton, Edmonton, AB, Canada
| | - Kathryn G. Todd
- Neurochemical Research Unit, Department of Psychiatry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
| | - Ian R. Winship
- Neurochemical Research Unit, Department of Psychiatry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
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8
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Hermes DJ, Yadav-Samudrala BJ, Xu C, Paniccia JE, Meeker RB, Armstrong ML, Reisdorph N, Cravatt BF, Mackie K, Lichtman AH, Ignatowska-Jankowska BM, Lysle DT, Fitting S. GPR18 drives FAAH inhibition-induced neuroprotection against HIV-1 Tat-induced neurodegeneration. Exp Neurol 2021; 341:113699. [PMID: 33736974 PMCID: PMC8984429 DOI: 10.1016/j.expneurol.2021.113699] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 02/05/2021] [Accepted: 03/11/2021] [Indexed: 02/03/2023]
Abstract
Human immunodeficiency virus type 1 (HIV-1) is known to provoke microglial immune responses which likely play a paramount role in the development of chronic neuroinflammatory conditions and neuronal damage related to HIV-1 associated neurocognitive disorders (HAND). In particular, HIV-1 Tat protein is a proinflammatory neurotoxin which predisposes neurons to synaptodendritic injury. Drugs targeting the degradative enzymes of endogenous cannabinoids have shown promise in reducing inflammation with minimal side effects in rodent models. Considering that markers of neuroinflammation can predict the extent of neuronal injury in HAND patients, we evaluated the neurotoxic effect of HIV-1 Tat-exposed microglia following blockade of fatty acid amid hydrolyze (FAAH), a catabolic enzyme responsible for degradation of endocannabinoids, e.g. anandamide (AEA). In the present study, cultured murine microglia were incubated with Tat and/or a FAAH inhibitor (PF3845). After 24 h, cells were imaged for morphological analysis and microglial conditioned media (MCM) was collected. Frontal cortex neuron cultures (DIV 7–11) were then exposed to MCM, and neurotoxicity was assessed via live cell calcium imaging and staining of actin positive dendritic structures. Results demonstrate a strong attenuation of microglial responses to Tat by PF3845 pretreatment, which is indicated by 1) microglial changes in morphology to a less proinflammatory phenotype using fractal analysis, 2) a decrease in release of neurotoxic cytokines/chemokines (MCP-1/CCL2) and matrix metalloproteinases (MMPs; MMP-9) using ELISA/multiplex assays, and 3) enhanced production of endocannabinoids (AEA) using LC/MS/MS. Additionally, PF3845’s effects on Tat-induced microglial-mediated neurotoxicity, decreased dysregulation of neuronal intracellular calcium and prevented the loss of actin-positive staining and punctate structure in frontal cortex neuron cultures. Interestingly, these observed neuroprotective effects appeared to be independent of cannabinoid receptor activity (CB1R & CB2R). We found that a purported GPR18 antagonist, CID-85469571, blocked the neuroprotective effects of PF3845 in all experiments. Collectively, these experiments increase understanding of the role of FAAH inhibition and Tat in mediating microglial neurotoxicity in the HAND condition.
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Affiliation(s)
- Douglas J Hermes
- Department of Psychology and Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America.
| | - Barkha J Yadav-Samudrala
- Department of Psychology and Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
| | - Changqing Xu
- Department of Psychology and Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
| | - Jacqueline E Paniccia
- Department of Psychology and Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
| | - Rick B Meeker
- Department of Neurology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
| | - Michael L Armstrong
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Denver, CO, United States of America
| | - Nichole Reisdorph
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Denver, CO, United States of America
| | - Benjamin F Cravatt
- Department of Chemistry, Scripps Research Institute, La Jolla, CA, United States of America
| | - Ken Mackie
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, United States of America
| | - Aron H Lichtman
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA, United States of America
| | | | - Donald T Lysle
- Department of Psychology and Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
| | - Sylvia Fitting
- Department of Psychology and Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America.
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Shao R, Sun D, Hu Y, Cui D. White matter injury in the neonatal hypoxic-ischemic brain and potential therapies targeting microglia. J Neurosci Res 2021; 99:991-1008. [PMID: 33416205 DOI: 10.1002/jnr.24761] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 10/27/2020] [Accepted: 11/01/2020] [Indexed: 12/12/2022]
Abstract
Neonatal hypoxic-ischemic (H-I) injury, which mainly causes neuronal damage and white matter injury (WMI), is among the predominant causes of infant morbidity (cerebral palsy, cognitive and persistent motor disabilities) and mortality. Disruptions to the oxygen and blood supply in the perinatal brain affect the cerebral microenvironment and may affect microglial activation, excitotoxicity, and oxidative stress. Microglia are significantly associated with axonal damage and myelinating oligodendrocytes, which are major pathological components of WMI. However, the effects of H-I injury on microglial functions and underlying transformation mechanisms remain poorly understood. The historical perception that these cells are major risk factors for ischemic stroke has been questioned due to our improved understanding of the diversity of microglial phenotypes and their alterable functions, which exacerbate or attenuate injuries in different regions in response to environmental instability. Unfortunately, although therapeutic hypothermia is an efficient treatment, death and disability remain the prognosis for a large proportion of neonates with H-I injury. Hence, novel neuroprotective therapies to treat WMI following H-I injury are urgently needed. Here, we review microglial mechanisms that might occur in the developing brain due to neonatal H-I injury and discuss whether microglia function as a double-edged sword in WMI. Then, we emphasize microglial heterogeneity, notably at the single-cell level, and sex-specific effects on the etiology of neurological diseases. Finally, we discuss current knowledge of strategies aiming to improve microglia modulation and remyelination following neonatal H-I injury. Overall, microglia-targeted therapy might provide novel and valuable insights into the treatment of neonatal H-I insult.
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Affiliation(s)
- Rongjiao Shao
- Department of Anesthesiology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Dawei Sun
- Department of Anesthesiology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Yue Hu
- Department of Anesthesiology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Derong Cui
- Department of Anesthesiology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
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10
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Vaz AR, Falcão AS, Scarpa E, Semproni C, Brites D. Microglia Susceptibility to Free Bilirubin Is Age-Dependent. Front Pharmacol 2020; 11:1012. [PMID: 32765258 PMCID: PMC7381152 DOI: 10.3389/fphar.2020.01012] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 06/23/2020] [Indexed: 12/20/2022] Open
Abstract
Increased concentrations of unconjugated bilirubin (UCB), namely its free fraction (Bf), in neonatal life may cause transient or definitive injury to neurons and glial cells. We demonstrated that UCB damages neurons and glial cells by compromising oligodendrocyte maturation and myelination, and by activating astrocytes and microglia. Immature neurons and astrocytes showed to be especially vulnerable. However, whether microglia susceptibility to UCB is also age-related was never investigated. We developed a microglia culture model in which cells at 2 days in vitro (2DIV) revealed to behave as the neonatal microglia (amoeboid/reactive cells), in contrast with those at 16DIV microglia that performed as aged cells (irresponsive/dormant cells). Here, we aimed to unveil whether UCB-induced toxicity diverged from the young to the long-cultured microglia. Cells were isolated from the cortical brain of 1- to 2-day-old CD1 mice and incubated for 24 h with 50/100 nM Bf levels, which were associated to moderate and severe neonatal hyperbilirubinemia, respectively. These concentrations of Bf induced early apoptosis and amoeboid shape in 2DIV microglia, while caused late apoptosis in 16DIV cells, without altering their morphology. CD11b staining increased in both, but more markedly in 2DIV cells. Likewise, the gene expression of HMGB1, a well-known alarmin, as well as HMGB1 and GLT-1–positive cells, were enhanced as compared to long-maturated microglia. The CX3CR1 reduction in 2DIV microglia was opposed to the 16DIV cells and suggests a preferential Bf-induced sickness response in younger cells. In conformity, increased mitochondrial mass and NO were enhanced in 2DIV cells, but unchanged or reduced, respectively, in the 16DIV microglia. However, 100 nM Bf caused iNOS gene overexpression in 2DIV and 16DIV cells. While only arginase 1/IL-1β gene expression levels increased upon 50/100 nM Bf treatment in long-maturated microglia, MHCII/arginase 1/TNF-α/IL-1β/IL-6 (>10-fold) were upregulated in the 2DIV microglia. Remarkably, enhanced inflammatory-associated microRNAs (miR-155/miR-125b/miR-21/miR-146a) and reduced anti-inflammatory miR-124 were found in young microglia by both Bf concentrations, while remained unchanged (miR/21/miR-125b) or decreased (miR-155/miR-146a/miR-124) in aged cells. Altogether, these findings support the neurodevelopmental susceptibilities to UCB-induced neurotoxicity, the most severe disabilities in premature babies, and the involvement of immune-inflammation neonatal microglia processes in poorer outcomes.
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Affiliation(s)
- Ana Rita Vaz
- Faculty of Pharmacy, Research Institute for Medicines (iMed.ULisboa), Universidade de Lisboa, Lisbon, Portugal.,Department of Biochemistry and Human Biology, Faculty of Pharmacy, Universidade de Lisboa, Lisbon, Portugal
| | - Ana Sofia Falcão
- Faculty of Pharmacy, Research Institute for Medicines (iMed.ULisboa), Universidade de Lisboa, Lisbon, Portugal.,Department of Biochemistry and Human Biology, Faculty of Pharmacy, Universidade de Lisboa, Lisbon, Portugal.,Chronic Diseases Research Centre (CEDOC), Nova Medical School, Universidade Nova de Lisboa, Lisbon, Portugal
| | - Eleonora Scarpa
- Faculty of Pharmacy, Research Institute for Medicines (iMed.ULisboa), Universidade de Lisboa, Lisbon, Portugal
| | - Carlotta Semproni
- Faculty of Pharmacy, Research Institute for Medicines (iMed.ULisboa), Universidade de Lisboa, Lisbon, Portugal
| | - Dora Brites
- Faculty of Pharmacy, Research Institute for Medicines (iMed.ULisboa), Universidade de Lisboa, Lisbon, Portugal.,Department of Biochemistry and Human Biology, Faculty of Pharmacy, Universidade de Lisboa, Lisbon, Portugal
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11
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Li LZ, Huang YY, Yang ZH, Zhang SJ, Han ZP, Luo YM. Potential microglia-based interventions for stroke. CNS Neurosci Ther 2020; 26:288-296. [PMID: 32064759 PMCID: PMC7052807 DOI: 10.1111/cns.13291] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 12/10/2019] [Accepted: 01/16/2020] [Indexed: 12/17/2022] Open
Abstract
A large number of families worldwide suffer from the physical and mental burden posed by stroke. An increasing number of studies aimed at the prevention and treatment of stroke have been conducted. Specifically, manipulating the immune response to stroke is under intense investigation. Microglia are the principal immune cells in the brain and are the first line of defense against the pathophysiology induced by stroke. Increasing evidence has suggested that microglia play diverse roles that depend on dynamic interactions with neurons, astrocytes, and other neighboring cells both in the normal brain and under pathological conditions, including stroke. Moreover, there are dynamic alterations in microglial functions with respect to aging and sex differences in the human brain, which offer a deep understanding of the conditions of stroke patients of different ages and sex. Hence, we review the dynamic microglial reactions caused by aging, sex, and crosstalk with neighboring cells both in normal conditions and after stroke and relevant potential interventions.
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Affiliation(s)
- Ling-Zhi Li
- Institute of Cerebrovascular Disease Research and Department of Neurology, Xuanwu Hospital of Capital Medical University, Beijing, China
| | - Yu-You Huang
- Institute of Cerebrovascular Disease Research and Department of Neurology, Xuanwu Hospital of Capital Medical University, Beijing, China
| | - Zhen-Hong Yang
- Institute of Cerebrovascular Disease Research and Department of Neurology, Xuanwu Hospital of Capital Medical University, Beijing, China
| | - Si-Jia Zhang
- Institute of Cerebrovascular Disease Research and Department of Neurology, Xuanwu Hospital of Capital Medical University, Beijing, China
| | - Zi-Ping Han
- Institute of Cerebrovascular Disease Research and Department of Neurology, Xuanwu Hospital of Capital Medical University, Beijing, China.,Beijing Geriatric Medical Research Center and Beijing Key Laboratory of Translational Medicine for Cerebrovascular Diseases, Beijing, China
| | - Yu-Min Luo
- Institute of Cerebrovascular Disease Research and Department of Neurology, Xuanwu Hospital of Capital Medical University, Beijing, China.,Beijing Geriatric Medical Research Center and Beijing Key Laboratory of Translational Medicine for Cerebrovascular Diseases, Beijing, China.,Beijing Institute for Brain Disorders, Beijing, China
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12
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Solís-Chagoyán H, Flores-Soto E, Valdés-Tovar M, Cercós MG, Calixto E, Montaño LM, Barajas-López C, Sommer B, Aquino-Gálvez A, Trueta C, Benítez-King GA. Purinergic Signaling Pathway in Human Olfactory Neuronal Precursor Cells. Stem Cells Int 2019; 2019:2728786. [PMID: 31065271 DOI: 10.1155/2019/2728786] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 01/29/2019] [Accepted: 02/07/2019] [Indexed: 12/23/2022] Open
Abstract
Extracellular ATP and trophic factors released by exocytosis modulate in vivo proliferation, migration, and differentiation in multipotent stem cells (MpSC); however, the purinoceptors mediating this signaling remain uncharacterized in stem cells derived from the human olfactory epithelium (hOE). Our aim was to determine the purinergic pathway in isolated human olfactory neuronal precursor cells (hONPC) that exhibit MpSC features. Cloning by limiting dilution from a hOE heterogeneous primary culture was performed to obtain a culture predominantly constituted by hONPC. Effectiveness of cloning to isolate MpSC-like precursors was corroborated through immunodetection of specific protein markers and by functional criteria such as self-renewal, proliferation capability, and excitability of differentiated progeny. P2 receptor expression in hONPC was determined by Western blot, and the role of these purinoceptors in the ATP-induced exocytosis and changes in cytosolic Ca2+ ([Ca2+]i) were evaluated using the fluorescent indicators FM1-43 and Fura-2 AM, respectively. The clonal culture was enriched with SOX2 and OCT3/4 transcription factors; additionally, the proportion of nestin-immunopositive cells, the proliferation capability, and functionality of differentiated progeny remained unaltered through the long-term clonal culture. hONPC expressed P2X receptor subtypes 1, 3-5, and 7, as well as P2Y2, 4, 6, and 11; ATP induced both exocytosis and a transient [Ca2+]i increase predominantly by activation of metabotropic P2Y receptors. Results demonstrated for the first time that ex vivo-expressed functional P2 receptors in MpSC-like hONPC regulate exocytosis and Ca2+ signaling. This purinergic-triggered release of biochemical messengers to the extracellular milieu might be involved in the paracrine signaling among hOE cells.
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13
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Saito M, Saito M, Das BC. Involvement of AMP-activated protein kinase in neuroinflammation and neurodegeneration in the adult and developing brain. Int J Dev Neurosci 2019; 77:48-59. [PMID: 30707928 DOI: 10.1016/j.ijdevneu.2019.01.007] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2018] [Revised: 12/29/2018] [Accepted: 01/28/2019] [Indexed: 02/07/2023] Open
Abstract
Microglial activation followed by neuroinflammation is a defense mechanism of the brain to eliminate harmful endogenous and exogenous materials including pathogens and damaged tissues, while excessive or chronic neuroinflammation may cause or exacerbate neurodegeneration observed in brain injuries and neurodegenerative diseases. Depending on conditions/environments during activation, microglia acquire distinct phenotypes, such as pro-inflammatory, anti-inflammatory, and disease-associated phenotypes, and show their ability to phagocytose various objects and produce pro-and anti-inflammatory mediators. Prevention of excessive inflammation by regulating the microglia's pro/anti-inflammatory balance is important for alleviating progression of brain injuries and diseases. Among many factors involved in the regulation of microglial phenotypes, cellular energy status plays an important role. Adenosine monophosphate-activated protein kinase (AMPK), which serves as a master sensor and regulator of energy balance, is considered a candidate molecule. Accumulating evidence from adult rodent studies indicates that AMPK activation promotes anti-inflammatory responses in microglia exposed to danger signals or various stressors mainly through inhibition of the nuclear factor κB (NF-κB) signaling and activation of the nuclear factor erythroid-2-related factor-2 (Nrf2) pathway. However, AMPK activation in neurons exposed to stressors/insults may exacerbate neuronal damage if AMPK activation is excessive or prolonged. While AMPK affects microglial activation states and neuronal cell survival rates in both the adult and the developing brain, studies in the developing brain are still scarce, even though activated AMPK is highly expressed especially in the neonatal brain. More in depth studies in the developing brain are important, because neuroinflammation/neurodegeneration occurred during development can result in long-lasting brain damage.
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Affiliation(s)
- Mariko Saito
- Division of Neurochemistry, Nathan S. Kline Institute for Psychiatric Research, 140 Old Orangeburg, Orangeburg, NY, 10962, USA.,Department of Psychiatry, New York University Langone Medical Center, 550 First Avenue, New York, NY, 10016, USA
| | - Mitsuo Saito
- Division of Analytical Psychopharmacology, Nathan S. Kline Institute for Psychiatric Research, 140 Old Orangeburg, Orangeburg, NY, 10962, USA
| | - Bhaskar C Das
- Departments of Medicine and Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, 1468 Madison Avenue, Annenberg 19-201, New York, NY, 10029, USA
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14
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Feng C, Liu S, Zhou F, Gao Y, Li Y, Du G, Chen Y, Jiao H, Feng J, Zhang Y, Bo D, Li Z, Fan G. Oxidative stress in the neurodegenerative brain following lifetime exposure to lead in rats: Changes in lifespan profiles. Toxicology 2019; 411:101-9. [DOI: 10.1016/j.tox.2018.11.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2018] [Revised: 10/26/2018] [Accepted: 11/12/2018] [Indexed: 12/27/2022]
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15
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Mishra A, Brinton RD. Inflammation: Bridging Age, Menopause and APOEε4 Genotype to Alzheimer's Disease. Front Aging Neurosci 2018; 10:312. [PMID: 30356809 PMCID: PMC6189518 DOI: 10.3389/fnagi.2018.00312] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 09/18/2018] [Indexed: 12/19/2022] Open
Abstract
Neuro-inflammatory processes that contribute to development of Alzheimer’s are evident early in the latent prodromal phase and worsen during the course of the disease. Despite substantial mechanistic and clinical evidence of inflammation, therapeutic approaches targeting inflammation have failed to alter the course of the disease. Disparate results from epidemiological and clinical trials targeting inflammation, highlight the complexity of the inflammatory process. Herein we review the dynamics of the inflammatory process across aging, midlife endocrine transitions, and the APOEε4 genotype and their contribution to progression of Alzheimer’s disease (AD). We discuss the chronic inflammatory processes that are activated during midlife chronological and endocrine aging, which ultimately limit the clearance capacity of microglia and lead to immune senescence. Aging, menopause, and APOEε4 combine the three hits of a compromised bioenergetic system of menopause with the chronic low grade innate inflammation of aging with the APOEε4 dyslipidemia and adaptive immune response. The inflammatory immune response is the unifying factor that bridges across each of the risk factors for AD. Immune system regulators that are specific to stage of disease and inflammatory phenotype would provide a therapeutic strategy to disconnect the bridge that drives disease. Outcomes of this analysis provide plausible mechanisms underlying failed clinical trials of anti-inflammatory agents in Alzheimer’s patients. Further, they highlight the need for stratifying AD clinical trial cohorts based on inflammatory phenotype. Combination therapies that include targeted use of anti-inflammatory agent’s specific to the immune phenotype are considered.
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Affiliation(s)
- Aarti Mishra
- Titus Family Department of Clinical Pharmacy, School of Pharmacy, University of Southern California, Los Angeles, CA, United States.,Center for Innovation in Brain Science, University of Arizona, Tucson, AZ, United States
| | - Roberta D Brinton
- Center for Innovation in Brain Science, University of Arizona, Tucson, AZ, United States.,Department of Pharmacology, College of Medicine, University of Arizona, Tucson, AZ, United States.,Department of Neurology, College of Medicine, University of Arizona, Tucson, AZ, United States
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16
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Smolders S, Notter T, Smolders SMT, Rigo JM, Brône B. Controversies and prospects about microglia in maternal immune activation models for neurodevelopmental disorders. Brain Behav Immun 2018; 73:51-65. [PMID: 29870753 DOI: 10.1016/j.bbi.2018.06.001] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 05/26/2018] [Accepted: 06/01/2018] [Indexed: 12/16/2022] Open
Abstract
Activation of the maternal immune system during pregnancy is a well-established risk factor for neuropsychiatric disease in the offspring, yet, the underlying mechanisms leading to altered brain function remain largely undefined. Microglia, the resident immune cells of the brain, are key to adequate development of the central nervous system (CNS), and are prime candidates to mediate maternal immune activation (MIA)-induced brain abnormalities. As such, the effects of MIA on the immunological phenotype of microglia has been widely investigated. However, contradicting results due to differences in read-out and methodological approaches impede final conclusions on MIA-induced microglial alterations. The aim of this review is to critically discuss the evidence for an activated microglial phenotype upon MIA.
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Affiliation(s)
- Silke Smolders
- Uhasselt - BIOMED, Hasselt, Belgium; Laboratory of Neuronal Differentiation, VIB Center for the Biology of Disease, Leuven and Center for Human Genetics, KU Leuven Leuven, Belgium.
| | - Tina Notter
- Institute of Pharmacology and Toxicology, University of Zurich-Vetsuisse, Zurich, Switzerland; Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland.
| | - Sophie M T Smolders
- Uhasselt - BIOMED, Hasselt, Belgium; INSERM, UMR S 1130, Université Pierre et Marie Curie Paris, France; CNRS, UMR 8246, Université Pierre et Marie Curie Paris, France; UM 119 NPS, Université Pierre et Marie Curie Paris, France.
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17
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Abstract
Production of pro-inflammatory and anti-inflammatory cytokines is part of the defense system that mostly microglia and macrophages display to induce normal signaling to counteract the deleterious actions of invading pathogens in the brain. Also, redox activity in the central nervous system (CNS) constitutes an integral part of the metabolic processes needed by cells to exert their normal molecular and biochemical functions. Under normal conditions, the formation of reactive oxygen and nitrogen species, and the following oxidative activity encounter a healthy balance with immunological responses to preserve cell functions in the brain. However, under different pathological conditions, inflammatory responses recruit pro-oxidant signals and vice versa. The aim of this article is to review the basic concepts about the triggering of inflammatory and oxidative responses in the CNS. Recent Advances: Diverse concurrent toxic pathways are described to provide a solid mechanistic scope for considering intervention at the experimental and clinical levels that are aimed at diminishing the harmful actions of these two contributing factors to nerve cell damage. Critical Issues and Future Directions: The main conclusion supports the existence of a narrow cross-talk between pro-inflammatory and oxidative signals that can lead to neuronal damage and subsequent neurodegeneration. Further investigation about critical pathways crosslinking oxidative stress and inflammation will strength our knowlegde on this topic. Antioxid. Redox Signal. 28, 1626-1651.
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Affiliation(s)
- Gabriela Aguilera
- 1 Laboratorio de Aminoácidos Excitadores, Instituto Nacional de Neurología y Neurocirugía , Mexico City, Mexico
| | - Ana Laura Colín-González
- 1 Laboratorio de Aminoácidos Excitadores, Instituto Nacional de Neurología y Neurocirugía , Mexico City, Mexico
| | - Edgar Rangel-López
- 1 Laboratorio de Aminoácidos Excitadores, Instituto Nacional de Neurología y Neurocirugía , Mexico City, Mexico
| | - Anahí Chavarría
- 2 Unidad de Investigación en Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México , Mexico City, Mexico
| | - Abel Santamaría
- 1 Laboratorio de Aminoácidos Excitadores, Instituto Nacional de Neurología y Neurocirugía , Mexico City, Mexico
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18
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Castillo-Ruiz A, Mosley M, George AJ, Mussaji LF, Fullerton EF, Ruszkowski EM, Jacobs AJ, Gewirtz AT, Chassaing B, Forger NG. The microbiota influences cell death and microglial colonization in the perinatal mouse brain. Brain Behav Immun 2018; 67:218-29. [PMID: 28890156 DOI: 10.1016/j.bbi.2017.08.027] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 08/18/2017] [Accepted: 08/23/2017] [Indexed: 12/21/2022] Open
Abstract
The mammalian fetus develops in a largely sterile environment, and direct exposure to a complex microbiota does not occur until birth. We took advantage of this to examine the effect of the microbiota on brain development during the first few days of life. The expression of anti- and pro-inflammatory cytokines, developmental cell death, and microglial colonization in the brain were compared between newborn conventionally colonized mice and mice born in sterile, germ-free (GF) conditions. Expression of the pro-inflammatory cytokines interleukin 1β and tumor necrosis factor α was markedly suppressed in GF newborns. GF mice also had altered cell death, with some regions exhibiting higher rates (paraventricular nucleus of the hypothalamus and the CA1 oriens layer of the hippocampus) and other regions exhibiting no change or lower rates (arcuate nucleus of the hypothalamus) of cell death. Microglial labeling was elevated in GF mice, due to an increase in both microglial cell size and number. The changes in cytokine expression, cell death and microglial labeling were evident on the day of birth, but were absent on embryonic day 18.5, approximately one-half day prior to expected delivery. Taken together, our results suggest that direct exposure to the microbiota at birth influences key neurodevelopmental events and does so within hours. These findings may help to explain some of the behavioral and neurochemical alterations previously seen in adult GF mice.
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19
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Alawieyah Syed Mortadza S, Sim JA, Neubrand VE, Jiang LH. A critical role of TRPM2 channel in Aβ42
-induced microglial activation and generation of tumor necrosis factor-α. Glia 2017; 66:562-575. [DOI: 10.1002/glia.23265] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 10/26/2017] [Accepted: 11/03/2017] [Indexed: 12/18/2022]
Affiliation(s)
- Sharifah Alawieyah Syed Mortadza
- School of Biomedical Sciences, Faculty of Biological Sciences; University of Leeds; Leeds UK
- Faculty of Medicine and Health Science; University Putra Malaysia; Selangor Malaysia
| | - Joan A. Sim
- School of Medicine; University of Manchester; Manchester UK
| | - Veronika E. Neubrand
- Department of Cell Biology and Immunology, IPBLN-CSIC, Avda Conocimiento, PT Ciencias de La Salud; Institute of Parasitology and Biomedicine López-Neyra; Granada Spain
| | - Lin-Hua Jiang
- School of Biomedical Sciences, Faculty of Biological Sciences; University of Leeds; Leeds UK
- Sino-UK Joint Laboratory of Brain Function and Injury of Henan Province and Department of Physiology and Neurobiology; Xinxiang Medical University; Xinxiang China
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20
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Zhao SC, Wang C, Xu H, Wu WQ, Chu ZH, Ma LS, Zhang YD, Liu F. Age-related differences in interferon regulatory factor-4 and -5 signaling in ischemic brains of mice. Acta Pharmacol Sin 2017; 38:1425-1434. [PMID: 28905935 DOI: 10.1038/aps.2017.122] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Accepted: 06/30/2017] [Indexed: 02/07/2023] Open
Abstract
Stroke is a disease that mainly affects the elderly. Since the age-related differences in stroke have not been well studied, modeling stroke in aged animals is clinically more relevant. The inflammatory responses to stroke are a fundamental pathological procedure, in which microglial activation plays an important role. Interferon regulatory factor-5 (IRF5) and IRF4 regulate M1 and M2 activation of macrophages, respectively, in peripheral inflammation; but it is unknown whether IRF5/IRF4 are also involved in cerebral inflammatory responses to stroke and whether age-related differences of the IRF5/IRF4 signaling exist in ischemic brain. Here, we investigated the influences of aging on IRF5/IRF4 signaling and post-stroke inflammation in mice. Both young (9-12 weeks) and aged (18 months) male mice were subjected to middle cerebral artery occlusion (MCAO). Morphological and biochemical changes in the ischemic brains and behavior deficits were assessed on 1, 3, and 7 d post-stroke. After MCAO, the aged mice showed smaller infarct sizes but higher neurological deficits and corner test scores than young mice. Young mice had higher levels of IRF4 and CD206 microglia in the ischemic brains, whereas the aged mice expressed more IRF5 and MHCII microglia. After MCAO, serum pro-inflammatory cytokines (TNF-α, iNOS, IL-6) were more prominently up-regulated in aged mice, whereas serum anti-inflammatory cytokines (TGF-β, IL-4, IL-10) were more prominently up-regulated in young mice. Our results demonstrate that aging has a significant influence on stroke outcomes in mice, which is probably mediated by age-specific inflammatory responses.
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21
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Spittau B. Aging Microglia-Phenotypes, Functions and Implications for Age-Related Neurodegenerative Diseases. Front Aging Neurosci 2017; 9:194. [PMID: 28659790 PMCID: PMC5469878 DOI: 10.3389/fnagi.2017.00194] [Citation(s) in RCA: 151] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 05/30/2017] [Indexed: 12/23/2022] Open
Abstract
Aging of the central nervous system (CNS) is one of the major risk factors for the development of neurodegenerative pathologies such as Parkinson’s disease (PD) and Alzheimer’s disease (AD). The molecular mechanisms underlying the onset of AD and especially PD are not well understood. However, neuroinflammatory responses mediated by microglia as the resident immune cells of the CNS have been reported for both diseases. The unique nature and developmental origin of microglia causing microglial self-renewal and telomere shortening led to the hypothesis that these CNS-specific innate immune cells become senescent. Age-dependent and senescence-driven impairments of microglia functions and responses have been suggested to play essential roles during onset and progression of neurodegenerative diseases. This review article summarizes the current knowledge of microglia phenotypes and functions in the aging CNS and further discusses the implications of these age-dependent microglia changes for the development and progression of AD and PD as the most common neurodegenerative diseases.
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Affiliation(s)
- Björn Spittau
- Department of Molecular Embryology, Faculty of Medicine, Institute for Anatomy and Cell Biology, University of FreiburgFreiburg, Germany.,Institute of Anatomy, University of RostockRostock, Germany
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22
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Kabba JA, Xu Y, Christian H, Ruan W, Chenai K, Xiang Y, Zhang L, Saavedra JM, Pang T. Microglia: Housekeeper of the Central Nervous System. Cell Mol Neurobiol 2017; 38:53-71. [PMID: 28534246 DOI: 10.1007/s10571-017-0504-2] [Citation(s) in RCA: 152] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 05/16/2017] [Indexed: 12/17/2022]
Abstract
Microglia, of myeloid origin, play fundamental roles in the control of immune responses and the maintenance of central nervous system homeostasis. These cells, just like peripheral macrophages, may be activated into M1 pro-inflammatory or M2 anti-inflammatory phenotypes by appropriate stimuli. Microglia do not respond in isolation, but form part of complex networks of cells influencing each other. This review addresses the complex interaction of microglia with each cell type in the brain: neurons, astrocytes, cerebrovascular endothelial cells, and oligodendrocytes. We also highlight the participation of microglia in the maintenance of homeostasis in the brain, and their roles in the development and progression of age-related neurodegenerative disorders.
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Affiliation(s)
- John Alimamy Kabba
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Drug Screening, Jiangsu Key Laboratory of Drug Discovery for Metabolic Diseases, Jiangsu Key Laboratory of Druggability of Biopharmaceuticals, China Pharmaceutical University, #24 Tong Jia Xiang Street, Nanjing, 210009, People's Republic of China
| | - Yazhou Xu
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Drug Screening, Jiangsu Key Laboratory of Drug Discovery for Metabolic Diseases, Jiangsu Key Laboratory of Druggability of Biopharmaceuticals, China Pharmaceutical University, #24 Tong Jia Xiang Street, Nanjing, 210009, People's Republic of China
| | - Handson Christian
- Department of Pharmacology, School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, People's Republic of China
| | - Wenchen Ruan
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Drug Screening, Jiangsu Key Laboratory of Drug Discovery for Metabolic Diseases, Jiangsu Key Laboratory of Druggability of Biopharmaceuticals, China Pharmaceutical University, #24 Tong Jia Xiang Street, Nanjing, 210009, People's Republic of China
| | - Kitchen Chenai
- School of Pharmacy, China Pharmaceutical University, Nanjing, 210009, People's Republic of China
| | - Yun Xiang
- Department of Laboratory Medicine, Wuhan Children's Hospital, Tongji Medical College, Huazhong University of Science & Technology, Wuhan, 430016, People's Republic of China
| | - Luyong Zhang
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Drug Screening, Jiangsu Key Laboratory of Drug Discovery for Metabolic Diseases, Jiangsu Key Laboratory of Druggability of Biopharmaceuticals, China Pharmaceutical University, #24 Tong Jia Xiang Street, Nanjing, 210009, People's Republic of China
| | - Juan M Saavedra
- Department of Pharmacology and Physiology, Georgetown University Medical Center, Washington DC, 20057, USA
| | - Tao Pang
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Drug Screening, Jiangsu Key Laboratory of Drug Discovery for Metabolic Diseases, Jiangsu Key Laboratory of Druggability of Biopharmaceuticals, China Pharmaceutical University, #24 Tong Jia Xiang Street, Nanjing, 210009, People's Republic of China. .,Department of Pharmacology and Physiology, Georgetown University Medical Center, Washington DC, 20057, USA.
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23
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Cai W, Zhang K, Li P, Zhu L, Xu J, Yang B, Hu X, Lu Z, Chen J. Dysfunction of the neurovascular unit in ischemic stroke and neurodegenerative diseases: An aging effect. Ageing Res Rev 2017; 34:77-87. [PMID: 27697546 PMCID: PMC5384332 DOI: 10.1016/j.arr.2016.09.006] [Citation(s) in RCA: 173] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 08/15/2016] [Accepted: 09/26/2016] [Indexed: 12/23/2022]
Abstract
Current understanding on the mechanisms of brain injury and neurodegeneration highlights an appreciation of multicellular interactions within the neurovascular unit (NVU), which include the evolution of blood-brain barrier (BBB) damage, neuronal cell death or degeneration, glial reaction, and immune cell infiltration. Aging is an important factor that influences the integrity of the NVU. The age-related physiological or pathological changes in the cellular components of the NVU have been shown to increase the vulnerability of the NVU to ischemia/reperfusion injury or neurodegeneration, and to result in deteriorated brain damage. This review describes the impacts of aging on each NVU component and discusses the mechanisms by which aging increases NVU sensitivity to stroke and neurodegenerative diseases. Prophylactic or therapeutic perspectives that may delay or diminish aging and thus prevent the incidence of these neurological disorders will also be reviewed.
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Affiliation(s)
- Wei Cai
- Geriatric Research, Education and Clinical Center, Veterans Affairs Pittsburgh Health Care System, Pittsburgh, PA 15261, USA; Department of Neurology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, 510630, China; Pittsburgh Institute of Brain Disorders and Recovery, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Kai Zhang
- Geriatric Research, Education and Clinical Center, Veterans Affairs Pittsburgh Health Care System, Pittsburgh, PA 15261, USA; Pittsburgh Institute of Brain Disorders and Recovery, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Peiying Li
- Department of Anesthesiology, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200127, China; Pittsburgh Institute of Brain Disorders and Recovery, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Ling Zhu
- Geriatric Research, Education and Clinical Center, Veterans Affairs Pittsburgh Health Care System, Pittsburgh, PA 15261, USA; Department of Anesthesiology, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200127, China; Pittsburgh Institute of Brain Disorders and Recovery, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Jing Xu
- Geriatric Research, Education and Clinical Center, Veterans Affairs Pittsburgh Health Care System, Pittsburgh, PA 15261, USA; Pittsburgh Institute of Brain Disorders and Recovery, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Boyu Yang
- Geriatric Research, Education and Clinical Center, Veterans Affairs Pittsburgh Health Care System, Pittsburgh, PA 15261, USA; Pittsburgh Institute of Brain Disorders and Recovery, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Xiaoming Hu
- Geriatric Research, Education and Clinical Center, Veterans Affairs Pittsburgh Health Care System, Pittsburgh, PA 15261, USA; Pittsburgh Institute of Brain Disorders and Recovery, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Zhengqi Lu
- Department of Neurology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, 510630, China.
| | - Jun Chen
- Geriatric Research, Education and Clinical Center, Veterans Affairs Pittsburgh Health Care System, Pittsburgh, PA 15261, USA; Pittsburgh Institute of Brain Disorders and Recovery, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA.
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24
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Bartlett R, Sluyter V, Watson D, Sluyter R, Yerbury JJ. P2X7 antagonism using Brilliant Blue G reduces body weight loss and prolongs survival in female SOD1 G93A amyotrophic lateral sclerosis mice. PeerJ 2017; 5:e3064. [PMID: 28265522 PMCID: PMC5335685 DOI: 10.7717/peerj.3064] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2016] [Accepted: 02/04/2017] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Amyotrophic lateral sclerosis (ALS) is a rapidly progressive neurodegenerative disease characterised by the accumulation of aggregated proteins, microglia activation and motor neuron loss. The mechanisms underlying neurodegeneration and disease progression in ALS are unknown, but the ATP-gated P2X7 receptor channel is implicated in this disease. Therefore, the current study aimed to examine P2X7 in the context of neurodegeneration, and investigate whether the P2X7 antagonist, Brilliant Blue G (BBG), could alter disease progression in a murine model of ALS. METHODS Human SOD1G93A transgenic mice, which normally develop ALS, were injected with BBG or saline, three times per week, from pre-onset of clinical disease (62-64 days of age) until end-stage. During the course of treatment mice were assessed for weight, clinical score and survival, and motor coordination, which was assessed by rotarod performance. Various parameters from end-stage mice were assessed as follows. Motor neuron loss and microgliosis were assessed by immunohistochemistry. Relative amounts of lumbar spinal cord SOD1 and P2X7 were quantified by immunoblotting. Serum monocyte chemoattractant protein-1 was measured by ELISA. Splenic leukocyte populations were assessed by flow cytometry. Relative expression of splenic and hepatic P2X7 mRNA was measured by quantitative real-time PCR. Lumbar spinal cord SOD1 and P2X7 were also quantified by immunoblotting in untreated female SOD1G93A mice during the course of disease. RESULTS BBG treatment reduced body weight loss in SOD1G93A mice of combined sex, but had no effect on clinical score, survival or motor coordination. BBG treatment reduced body weight loss in female, but not male, SOD1G93A mice. BBG treatment also prolonged survival in female, but not male, SOD1G93A mice, extending the mean survival time by 4.3% in female mice compared to female mice treated with saline. BBG treatment had no effect on clinical score or motor coordination in either sex. BBG treatment had no major effect on any end-stage parameters. Total amounts of lumbar spinal cord SOD1 and P2X7 in untreated female SOD1G93A mice did not change over time. DISCUSSION Collectively, this data suggests P2X7 may have a partial role in ALS progression in mice, but additional research is required to fully elucidate the contribution of this receptor in this disease.
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Affiliation(s)
- Rachael Bartlett
- Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia
- School of Biological Sciences, University of Wollongong, Wollongong, NSW, Australia
- Centre for Medical and Molecular Biosciences, Wollongong, NSW, Australia
| | - Vanessa Sluyter
- Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia
- School of Biological Sciences, University of Wollongong, Wollongong, NSW, Australia
- Centre for Medical and Molecular Biosciences, Wollongong, NSW, Australia
| | - Debbie Watson
- Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia
- School of Biological Sciences, University of Wollongong, Wollongong, NSW, Australia
- Centre for Medical and Molecular Biosciences, Wollongong, NSW, Australia
| | - Ronald Sluyter
- Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia
- School of Biological Sciences, University of Wollongong, Wollongong, NSW, Australia
- Centre for Medical and Molecular Biosciences, Wollongong, NSW, Australia
| | - Justin J. Yerbury
- Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia
- School of Biological Sciences, University of Wollongong, Wollongong, NSW, Australia
- Centre for Medical and Molecular Biosciences, Wollongong, NSW, Australia
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Pierre WC, Smith PLP, Londono I, Chemtob S, Mallard C, Lodygensky GA. Neonatal microglia: The cornerstone of brain fate. Brain Behav Immun 2017; 59:333-345. [PMID: 27596692 DOI: 10.1016/j.bbi.2016.08.018] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Revised: 07/30/2016] [Accepted: 08/29/2016] [Indexed: 12/16/2022] Open
Abstract
Microglia, mainly known for their role in innate immunity and modulation of neuroinflammation, play an active role in central nervous system development and homeostasis. Depending on the context and environmental stimuli, microglia adopt a broad spectrum of activation status from pro-inflammatory, associated with neurotoxicity, to anti-inflammatory linked to neuroprotection. Pro-inflammatory microglial activation is a key hallmark of white matter injury in preterm infants and is involved in developmental origin of adult neurological diseases. Characterization of neonatal microglia function in brain development and inflammation has allowed the investigation of promising therapeutic targets with potential long-lasting neuroprotective effects. True prevention of neuro-degenerative diseases might eventually occur as early as the perinatal period.
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Affiliation(s)
- Wyston C Pierre
- Sainte-Justine Hospital and Research Center, Department of Pediatrics, Université de Montréal, 3175 Chemin de la Côte-Sainte-Catherine, Montréal, Québec, Canada
| | - Peter L P Smith
- Perinatal Center, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, 405 30 Gothenburg, Sweden
| | - Irène Londono
- Sainte-Justine Hospital and Research Center, Department of Pediatrics, Université de Montréal, 3175 Chemin de la Côte-Sainte-Catherine, Montréal, Québec, Canada
| | - Sylvain Chemtob
- Sainte-Justine Hospital and Research Center, Department of Pediatrics, Université de Montréal, 3175 Chemin de la Côte-Sainte-Catherine, Montréal, Québec, Canada; Departments of Ophtalmology, Université de Montréal, Montreal, Quebec, Canada; Departments of Pharmacology, Université de Montréal, Montreal, Quebec, Canada
| | - Carina Mallard
- Perinatal Center, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, 405 30 Gothenburg, Sweden
| | - Gregory A Lodygensky
- Sainte-Justine Hospital and Research Center, Department of Pediatrics, Université de Montréal, 3175 Chemin de la Côte-Sainte-Catherine, Montréal, Québec, Canada; Montreal Heart Institute, 5000 Rue Bélanger, Montreal, Quebec, Canada; Department of Neuroscience, Université de Montréal, Montreal, Quebec, Canada; Departments of Pharmacology, Université de Montréal, Montreal, Quebec, Canada.
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Wang C, Tao S, Fang Y, Guo J, Zhu L, Zhang S. Infiltrating cells from host brain restore the microglial population in grafted cortical tissue. Sci Rep 2016; 6:33080. [PMID: 27615195 DOI: 10.1038/srep33080] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 08/19/2016] [Indexed: 12/20/2022] Open
Abstract
Transplantation of embryonic cortical tissue is considered as a promising therapy for brain injury. Grafted neurons can reestablish neuronal network and improve cortical function of the host brain. Microglia is a key player in regulating neuronal survival and plasticity, but its activation and dynamics in grafted cortical tissue remain unknown. Using two-photon intravital imaging and parabiotic model, here we investigated the proliferation and source of microglia in the donor region by transplanting embryonic cortical tissue into adult cortex. Live imaging showed that the endogenous microglia of the grafted tissue were rapidly lost after transplantation. Instead, host-derived microglia infiltrated and colonized the graft. Parabiotic model suggested that the main source of infiltrating cells is the parenchyma of the host brain. Colonized microglia proliferated and experienced an extensive morphological transition and eventually differentiated into resting ramified morphology. Collectively, these results demonstrated that donor tissue has little contribution to the activated microglia and host brain controls the microglial population in the graft.
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Das A, Kim SH, Arifuzzaman S, Yoon T, Chai JC, Lee YS, Park KS, Jung KH, Chai YG. Transcriptome sequencing reveals that LPS-triggered transcriptional responses in established microglia BV2 cell lines are poorly representative of primary microglia. J Neuroinflammation 2016; 13:182. [PMID: 27400875 PMCID: PMC4940985 DOI: 10.1186/s12974-016-0644-1] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 06/27/2016] [Indexed: 12/22/2022] Open
Abstract
Background Microglia are resident myeloid cells in the CNS that are activated by infection, neuronal injury, and inflammation. Established BV2 microglial cell lines have been the primary in vitro models used to study neuroinflammation for more than a decade because they reduce the requirement of continuously maintaining cell preparations and animal experimentation models. However, doubt has recently been raised regarding the value of BV2 cell lines as a model system. Methods We used triplicate RNA sequencing (RNA-seq) to investigate the molecular signature of primary and BV2 microglial cell lines using two transcriptomic techniques: global transcriptomic biological triplicate RNA-seq and quantitative real-time PCR. We analyzed differentially expressed genes (DEGs) to identify transcription factor (TF) motifs (−950 to +50 bp of the 5′ upstream promoters) and epigenetic mechanisms. Results Sequencing assessment and quality evaluation revealed that primary microglia have a distinct transcriptomic signature and express a unique cluster of transcripts in response to lipopolysaccharide. This microglial signature was not observed in BV2 microglial cell lines. Importantly, we observed that previously unidentified TFs (i.e., IRF2, IRF5, IRF8, STAT1, STAT2, and STAT5A) and the epigenetic regulators KDM1A, NSD3, and SETDB2 were significantly and selectively expressed in primary microglia (PM). Although transcriptomic alterations known to occur in BV2 microglial cell lines were identified in PM, we also observed several novel transcriptomic alterations in PM that are not frequently observed in BV2 microglial cell lines. Conclusions Collectively, these unprecedented findings demonstrate that established BV2 microglial cell lines are probably a poor representation of PM, and we establish a resource for future studies of neuroinflammation. Electronic supplementary material The online version of this article (doi:10.1186/s12974-016-0644-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Amitabh Das
- Institute of Natural Science and Technology, Hanyang University, Ansan, 15588, Republic of Korea
| | - Sun Hwa Kim
- Department of Molecular and Life Sciences, Hanyang University, Ansan, 15588, Republic of Korea
| | - Sarder Arifuzzaman
- Department of Bionanotechnology, Hanyang University, Seoul, 04673, Republic of Korea
| | - Taeho Yoon
- Department of Molecular and Life Sciences, Hanyang University, Ansan, 15588, Republic of Korea
| | - Jin Choul Chai
- Department of Molecular and Life Sciences, Hanyang University, Ansan, 15588, Republic of Korea
| | - Young Seek Lee
- Department of Molecular and Life Sciences, Hanyang University, Ansan, 15588, Republic of Korea
| | - Kyoung Sun Park
- Institute of Natural Science and Technology, Hanyang University, Ansan, 15588, Republic of Korea
| | - Kyoung Hwa Jung
- Institute of Natural Science and Technology, Hanyang University, Ansan, 15588, Republic of Korea.
| | - Young Gyu Chai
- Department of Molecular and Life Sciences, Hanyang University, Ansan, 15588, Republic of Korea. .,Department of Bionanotechnology, Hanyang University, Seoul, 04673, Republic of Korea.
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Polazzi E, Mengoni I, Peña-Altamira E, Massenzio F, Virgili M, Petralla S, Monti B. Neuronal Regulation of Neuroprotective Microglial Apolipoprotein E Secretion in Rat In Vitro Models of Brain Pathophysiology. J Neuropathol Exp Neurol 2015; 74:818-34. [PMID: 26185969 DOI: 10.1097/NEN.0000000000000222] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Apolipoprotein E (ApoE) is mainly secreted by glial cells and is involved in many brain functions, including neuronal plasticity, β-amyloid clearance, and neuroprotection. Microglia--the main immune cells of the brain--are one source of ApoE, but little is known about the physiologic regulation of microglial ApoE secretion by neurons and whether this release changes under inflammatory or neurodegenerative conditions. Using rat primary neural cell cultures, we show that microglia release ApoE through a Golgi-mediated secretion pathway and that ApoE progressively accumulates in neuroprotective microglia-conditioned medium. This constitutive ApoE release is negatively affected by microglial activation both with lipopolysaccharide and with ATP. Microglial ApoE release is stimulated by neuron-conditioned media and under coculture conditions. Neuron-stimulated microglial ApoE release is mediated by serine and glutamate through N-methyl-D-aspartate receptors and is differently regulated by activation states (i.e. lipopolysaccharide vs ATP) and by 6-hydroxydopamine. Microglial ApoE silencing abrogated protection of cerebellar granule neurons against 6-hydroxydopamine toxicity in cocultures, indicating that microglial ApoE release is neuroprotective. Our findings shed light on the reciprocal cross-talk between neurons and microglia that is crucial for normal brain functions. They also open the way for the identification of possible pharmacologic targets that can modulate neuroprotective microglial ApoE release under pathologic conditions.
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Teo JD, Morris MJ, Jones NM. Hypoxic postconditioning reduces microglial activation, astrocyte and caspase activity, and inflammatory markers after hypoxia-ischemia in the neonatal rat brain. Pediatr Res 2015; 77:757-64. [PMID: 25751571 DOI: 10.1038/pr.2015.47] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Accepted: 11/12/2014] [Indexed: 11/09/2022]
Abstract
BACKGROUND Postconditioning (PostC) with mild hypoxia shortly after a neonatal hypoxic-ischemic (HI) brain injury can reduce brain damage, however, the mechanisms underlying this protection are not known. We hypothesize that hypoxic PostC reduces brain markers of glial activity, inflammation, and apoptosis following HI injury. METHODS Sprague Dawley rat pups were exposed to right common carotid artery occlusion and hypoxia (7% oxygen, 3 h) on postnatal day 7 and 24 h later, pups were exposed to hypoxic PostC (8% O2 for 1 h/day for 5 d) or kept at ambient conditions for the same duration. HI+N pups demonstrated ~10% loss in ipsilateral brain tissue which was rescued with HI+PostC. To investigate the cellular responses, markers of astrocytes, microglia, inflammation, and caspase 3 activity were examined using immunohistochemistry and enzyme-linked immunosorbent assay. RESULTS PostC reduced the area of astrocyte staining compared to HI+N. There was also a shift in microglial morphology toward a primed state in both PostC groups. Protein levels of interleukin-1β and caspase 3 were elevated in HI+N brains and reduced by PostC. CONCLUSION This is the first demonstration that PostC can reduce glial activity, inflammatory mediators, and cell death after a neonatal HI brain injury.
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Affiliation(s)
- Jonathan D Teo
- Department of Pharmacology, School of Medical Sciences, University of New South Wales, New South Wales, Australia
| | - Margaret J Morris
- Department of Pharmacology, School of Medical Sciences, University of New South Wales, New South Wales, Australia
| | - Nicole M Jones
- Department of Pharmacology, School of Medical Sciences, University of New South Wales, New South Wales, Australia
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Dean JM, Shi Z, Fleiss B, Gunn KC, Groenendaal F, van Bel F, Derrick M, Juul SE, Tan S, Gressens P, Mallard C, Bennet L, Gunn AJ. A Critical Review of Models of Perinatal Infection. Dev Neurosci 2015; 37:289-304. [DOI: 10.1159/000370309] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Accepted: 12/02/2014] [Indexed: 11/19/2022] Open
Abstract
One of the central, unanswered questions in perinatology is why preterm infants continue to have such poor long-term neurodevelopmental, cognitive and learning outcomes, even though severe brain injury is now rare. There is now strong clinical evidence that one factor underlying disability may be infection, as well as nonspecific inflammation, during fetal and early postnatal life. In this review, we examine the experimental evidence linking both acute and chronic infection/inflammation with perinatal brain injury and consider key experimental determinants, including the microglia response, relative brain and immune maturity and the pattern of exposure to infection. We highlight the importance of the origin and derivation of the bacterial cell wall component lipopolysaccharide. Such experimental paradigms are essential to determine the precise time course of the inflammatory reaction and to design targeted neuroprotective strategies to protect the perinatal brain from infection and inflammation.
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31
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Churchward MA, Todd KG. Statin treatment affects cytokine release and phagocytic activity in primary cultured microglia through two separable mechanisms. Mol Brain 2014; 7:85. [PMID: 25424483 PMCID: PMC4247600 DOI: 10.1186/s13041-014-0085-7] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Accepted: 11/08/2014] [Indexed: 12/14/2022] Open
Abstract
Background As the primary immune cells of the central nervous system, microglia contribute to development, homeostasis, and plasticity of the central nervous system, in addition to their well characterized roles in the foreign body and inflammatory responses. Increasingly, inappropriate activation of microglia is being reported as a component of inflammation in neurodegenerative and neuropsychiatric disorders. The statin class of cholesterol-lowering drugs have been observed to have anti-inflammatory and protective effects in both neurodegenerative diseases and ischemic stroke, and are suggested to act by attenuating microglial activity. Results We sought to investigate the effects of simvastatin treatment on the secretory profile and phagocytic activity of primary cultured rat microglia, and to dissect the mechanism of action of simvastatin on microglial activity. Simvastatin treatment altered the release of cytokines and trophic factors from microglia, including interleukin-1-β, tumour necrosis factor-α, and brain derived neurotrophic factor in a cholesterol-dependent manner. Conversely, simvastatin inhibited phagocytosis in microglia in a cholesterol-independent manner. Conclusions The disparity in cholesterol dependence of cytokine release and phagocytosis suggests the two effects occur through distinct molecular mechanisms. These two pathways may provide an opportunity for further refinement of pharmacotherapies for neuroinflammatory, neurodegenerative, and neuropsychiatric disorders.
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Affiliation(s)
- Matthew A Churchward
- Neurochemical Research Unit, University of Alberta Faculty of Medicine, Edmonton, AB, Canada, T6G 2R3. .,Department of Psychiatry, University of Alberta Faculty of Medicine, Edmonton, AB, Canada, T6G 2R3.
| | - Kathryn G Todd
- Neurochemical Research Unit, University of Alberta Faculty of Medicine, Edmonton, AB, Canada, T6G 2R3. .,Department of Psychiatry, University of Alberta Faculty of Medicine, Edmonton, AB, Canada, T6G 2R3. .,Neuroscience and Mental Health Institute, University of Alberta Faculty of Medicine, Edmonton, AB, Canada, T6G 2R3.
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Lucke-Wold BP, Turner RC, Logsdon AF, Bailes JE, Huber JD, Rosen CL. Linking traumatic brain injury to chronic traumatic encephalopathy: identification of potential mechanisms leading to neurofibrillary tangle development. J Neurotrauma 2014; 31:1129-38. [PMID: 24499307 PMCID: PMC4089022 DOI: 10.1089/neu.2013.3303] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Significant attention has recently been drawn to the potential link between head trauma and the development of neurodegenerative disease, namely chronic traumatic encephalopathy (CTE). The acute neurotrauma associated with sports-related concussions in athletes and blast-induced traumatic brain injury in soldiers elevates the risk for future development of chronic neurodegenerative diseases such as CTE. CTE is a progressive disease distinguished by characteristic tau neurofibrillary tangles (NFTs) and, occasionally, transactive response DNA binding protein 43 (TDP43) oligomers, both of which have a predilection for perivascular and subcortical areas near reactive astrocytes and microglia. The disease is currently only diagnosed postmortem by neuropathological identification of NFTs. A recent workshop sponsored by National Institute of Neurological Disorders and Stroke emphasized the need for premortem diagnosis, to better understand disease pathophysiology and to develop targeted treatments. In order to accomplish this objective, it is necessary to discover the mechanistic link between acute neurotrauma and the development of chronic neurodegenerative and neuropsychiatric disorders such as CTE. In this review, we briefly summarize what is currently known about CTE development and pathophysiology, and subsequently discuss injury-induced pathways that warrant further investigation. Understanding the mechanistic link between acute brain injury and chronic neurodegeneration will facilitate the development of appropriate diagnostic and therapeutic options for CTE and other related disorders.
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Affiliation(s)
- Brandon Peter Lucke-Wold
- Department of Neurosurgery, West Virginia University School of Medicine, Morgantown, West Virginia
- The Center for Neuroscience, West Virginia University School of Medicine, Morgantown, West Virginia
| | - Ryan Coddington Turner
- Department of Neurosurgery, West Virginia University School of Medicine, Morgantown, West Virginia
- The Center for Neuroscience, West Virginia University School of Medicine, Morgantown, West Virginia
| | - Aric Flint Logsdon
- The Center for Neuroscience, West Virginia University School of Medicine, Morgantown, West Virginia
- Department of Basic Pharmaceutical Sciences, West Virginia University School of Medicine, Morgantown, West Virginia
| | - Julian Edwin Bailes
- Department of Neurosurgery, NorthShore University Health System, University of Chicago Pritzker School of Medicine, Evanston, Illinois
| | - Jason Delwyn Huber
- The Center for Neuroscience, West Virginia University School of Medicine, Morgantown, West Virginia
- Department of Basic Pharmaceutical Sciences, West Virginia University School of Medicine, Morgantown, West Virginia
| | - Charles Lee Rosen
- Department of Neurosurgery, West Virginia University School of Medicine, Morgantown, West Virginia
- The Center for Neuroscience, West Virginia University School of Medicine, Morgantown, West Virginia
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Baskar Jesudasan SJ, Todd KG, Winship IR. Reduced inflammatory phenotype in microglia derived from neonatal rat spinal cord versus brain. PLoS One 2014; 9:e99443. [PMID: 24914808 DOI: 10.1371/journal.pone.0099443] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Accepted: 05/15/2014] [Indexed: 12/22/2022] Open
Abstract
Microglia are the primary immune cells of the central nervous system (CNS). Membrane bound sensors on their processes monitor the extracellular environment and respond to perturbations of the CNS such as injury or infection. Once activated, microglia play a crucial role in determining neuronal survival. Recent studies suggest that microglial functional response properties vary across different regions of the CNS. However, the activation profiles of microglia derived from the spinal cord have not been evaluated against brain microglia in vitro. Here, we studied the morphological properties and secretion of inflammatory and trophic effectors by microglia derived from the brain or spinal cord of neonatal rats under basal culture conditions and after activation with lipopolysaccharide (LPS). Our results demonstrate that spinal microglia assume a less inflammatory phenotype after LPS activation, with reduced release of the inflammatory effectors tumor necrosis factor alpha, interleukin-1 beta, and nitric oxide, a less amoeboid morphology, and reduced phagocytosis relative to brain-derived microglia. Phenotypic differences between brain and spinal microglia are an important consideration when evaluating anti-inflammatory or immunomodulatory therapies for brain versus spinal injury.
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Caldeira C, Oliveira AF, Cunha C, Vaz AR, Falcão AS, Fernandes A, Brites D. Microglia change from a reactive to an age-like phenotype with the time in culture. Front Cell Neurosci 2014; 8:152. [PMID: 24917789 PMCID: PMC4040822 DOI: 10.3389/fncel.2014.00152] [Citation(s) in RCA: 120] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Accepted: 05/13/2014] [Indexed: 01/25/2023] Open
Abstract
Age-related neurodegenerative diseases have been associated with chronic neuroinflammation and microglia activation. However, cumulative evidence supports that inflammation only occurs at an early stage once microglia change the endogenous characteristics with aging and switch to irresponsive/senescent and dystrophic phenotypes with disease progression. Thus, it will be important to have the means to assess the role of reactive and aged microglia when studying advanced brain neurodegeneration processes and age-associated related disorders. Yet, most studies are done with microglia from neonates since there are no adequate means to isolate degenerating microglia for experimentation. Indeed, only a few studies report microglia isolation from aged animals, using either short-term cultures or high concentrations of mitogens in the medium, which trigger microglia reactivity. The purpose of this study was to develop an experimental process to naturally age microglia after isolation from neonatal mice and to characterize the cultured cells at 2 days in vitro (DIV), 10 DIV, and 16 DIV. We found that 2 DIV (young) microglia had predominant amoeboid morphology and markers of stressed/reactive phenotype. In contrast, 16 DIV (aged) microglia evidenced ramified morphology and increased matrix metalloproteinase (MMP)-2 activation, as well as reduced MMP-9, glutamate release and nuclear factor kappa-B activation, in parallel with decreased expression of Toll-like receptor (TLR)-2 and TLR-4, capacity to migrate and phagocytose. These findings together with the reduced expression of microRNA (miR)-124, and miR-155, decreased autophagy, enhanced senescence associated beta-galactosidase activity and elevated miR-146a expression, are suggestive that 16 DIV cells mainly correspond to irresponsive/senescent microglia. Data indicate that the model represent an opportunity to understand and control microglial aging, as well as to explore strategies to recover microglia surveillance function.
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Affiliation(s)
- Cláudia Caldeira
- Research Institute for Medicines - iMed.ULisboa, Faculdade de Farmácia, Universidade de Lisboa Lisboa, Portugal ; Centro de Investigação Interdisciplinar Egas Moniz, Egas Moniz - Cooperativa de Ensino Superior, CRL, Campus Universitário Monte de Caparica, Portugal
| | - Ana F Oliveira
- Research Institute for Medicines - iMed.ULisboa, Faculdade de Farmácia, Universidade de Lisboa Lisboa, Portugal
| | - Carolina Cunha
- Research Institute for Medicines - iMed.ULisboa, Faculdade de Farmácia, Universidade de Lisboa Lisboa, Portugal
| | - Ana R Vaz
- Research Institute for Medicines - iMed.ULisboa, Faculdade de Farmácia, Universidade de Lisboa Lisboa, Portugal ; Department of Biochemistry and Human Biology, Faculdade de Farmácia, Universidade de Lisboa Lisboa, Portugal
| | - Ana S Falcão
- Research Institute for Medicines - iMed.ULisboa, Faculdade de Farmácia, Universidade de Lisboa Lisboa, Portugal ; Department of Biochemistry and Human Biology, Faculdade de Farmácia, Universidade de Lisboa Lisboa, Portugal
| | - Adelaide Fernandes
- Research Institute for Medicines - iMed.ULisboa, Faculdade de Farmácia, Universidade de Lisboa Lisboa, Portugal ; Department of Biochemistry and Human Biology, Faculdade de Farmácia, Universidade de Lisboa Lisboa, Portugal
| | - Dora Brites
- Research Institute for Medicines - iMed.ULisboa, Faculdade de Farmácia, Universidade de Lisboa Lisboa, Portugal ; Department of Biochemistry and Human Biology, Faculdade de Farmácia, Universidade de Lisboa Lisboa, Portugal
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Baburamani AA, Supramaniam VG, Hagberg H, Mallard C. Microglia toxicity in preterm brain injury. Reprod Toxicol 2014; 48:106-12. [PMID: 24768662 DOI: 10.1016/j.reprotox.2014.04.002] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Revised: 04/01/2014] [Accepted: 04/14/2014] [Indexed: 01/07/2023]
Abstract
Microglia responses in the preterm human brain in association with injury. Microglia responses in animal models of preterm brain injury. Mechanisms of microglia toxicity from in vitro primary microglia cell culture experiments.
Microglia are the resident phagocytic cells of the central nervous system. During brain development they are also imperative for apoptosis of excessive neurons, synaptic pruning, phagocytosis of debris and maintaining brain homeostasis. Brain damage results in a fast and dynamic microglia reaction, which can influence the extent and distribution of subsequent neuronal dysfunction. As a consequence, microglia responses can promote tissue protection and repair following brain injury, or become detrimental for the tissue integrity and functionality. In this review, we will describe microglia responses in the human developing brain in association with injury, with particular focus on the preterm infant. We also explore microglia responses and mechanisms of microglia toxicity in animal models of preterm white matter injury and in vitro primary microglia cell culture experiments.
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Abstract
Microglia are the principal resident innate immune cells of the CNS. Their contributions to the normal development of the CNS, the maintenance and plasticity of neuronal networks and the safeguarding of proper functionality are becoming more and more evident. Microglia also survey the tissue homeostasis to respond rapidly to exogenous and endogenous threats, primarily with a protective outcome. However, excessive acute activation, chronic activity or an improper adaptation of their functional performance can foster neuropathologies. A key to the versatile response behavior of these cells is their ability to commit to reactive phenotypes, which reveal enormous complexity. Yet the respective profiles of induced genes and installed functions may build up on heterogeneous contributions of cellular subsets. Here, we discuss findings and concepts that consider the variety of microglial activities and response options as being based-at least in part-on a diversity of the engaged cells. Whether it is the production of proinflammatory cytokines, clearance of tissue debris, antigen presentation or the ability to sense neurotransmitters, microglial cells present with an unanticipated heterogeneity of their constitutive and inducible features. While the organizational principles of this heterogeneity are still largely unknown, functional implications are already perceptible.
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Affiliation(s)
- Ulla Gertig
- Institute of Neuropathology, University of Göttingen Göttingen, Germany
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Mosher KI, Wyss-Coray T. Microglial dysfunction in brain aging and Alzheimer's disease. Biochem Pharmacol 2014; 88:594-604. [PMID: 24445162 DOI: 10.1016/j.bcp.2014.01.008] [Citation(s) in RCA: 407] [Impact Index Per Article: 40.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Revised: 01/06/2014] [Accepted: 01/07/2014] [Indexed: 12/23/2022]
Abstract
Microglia, the immune cells of the central nervous system, have long been a subject of study in the Alzheimer's disease (AD) field due to their dramatic responses to the pathophysiology of the disease. With several large-scale genetic studies in the past year implicating microglial molecules in AD, the potential significance of these cells has become more prominent than ever before. As a disease that is tightly linked to aging, it is perhaps not entirely surprising that microglia of the AD brain share some phenotypes with aging microglia. Yet the relative impacts of both conditions on microglia are less frequently considered in concert. Furthermore, microglial "activation" and "neuroinflammation" are commonly analyzed in studies of neurodegeneration but are somewhat ill-defined concepts that in fact encompass multiple cellular processes. In this review, we have enumerated six distinct functions of microglia and discuss the specific effects of both aging and AD. By calling attention to the commonalities of these two states, we hope to inspire new approaches for dissecting microglial mechanisms.
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Affiliation(s)
- Kira Irving Mosher
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, California 94305, USA; Neuroscience IDP Program, Stanford University School of Medicine, Stanford, California 94305, USA
| | - Tony Wyss-Coray
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, California 94305, USA; Center for Tissue Regeneration, Repair and Restoration, Veterans Administration Palo Alto Health Care System, Palo Alto, California 94304, USA.
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