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Hedley KE, Gomez HM, Kecelioglu E, Carroll OR, Jobling P, Horvat JC, Tadros MA. Neonatal Chlamydia muridarum respiratory infection causes neuroinflammation within the brainstem during the early postnatal period. J Neuroinflammation 2024; 21:158. [PMID: 38879567 PMCID: PMC11179230 DOI: 10.1186/s12974-024-03150-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Accepted: 06/10/2024] [Indexed: 06/19/2024] Open
Abstract
Respiratory infections are one of the most common causes of illness and morbidity in neonates worldwide. In the acute phase infections are known to cause wide-spread peripheral inflammation. However, the inflammatory consequences to the critical neural control centres for respiration have not been explored. Utilising a well characterised model of neonatal respiratory infection, we investigated acute responses within the medulla oblongata which contains key respiratory regions. Neonatal mice were intranasally inoculated within 24 h of birth, with either Chlamydia muridarum or sham-infected, and tissue collected on postnatal day 15, the peak of peripheral inflammation. A key finding of this study is that, while the periphery appeared to show no sex-specific effects of a neonatal respiratory infection, sex had a significant impact on the inflammatory response of the medulla oblongata. There was a distinct sex-specific response in the medulla coincident with peak of peripheral inflammation, with females demonstrating an upregulation of anti-inflammatory cytokines and males showing very few changes. Microglia also demonstrated sex-specificity with the morphology of females and males differing based upon the nuclei. Astrocytes showed limited changes during the acute response to neonatal infection. These data highlight the strong sex-specific impact of a respiratory infection can have on the medulla in the acute inflammatory phase.
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Affiliation(s)
- Kateleen E Hedley
- School of Biomedical Sciences & Pharmacy, The University of Newcastle Callaghan, NSW, 2308, Australia
- Hunter Medical Research Institute, New Lambton Heights, NSW, Australia
| | - Henry M Gomez
- School of Biomedical Sciences & Pharmacy, The University of Newcastle Callaghan, NSW, 2308, Australia
- Hunter Medical Research Institute, New Lambton Heights, NSW, Australia
| | - Eda Kecelioglu
- School of Biomedical Sciences & Pharmacy, The University of Newcastle Callaghan, NSW, 2308, Australia
- Hunter Medical Research Institute, New Lambton Heights, NSW, Australia
| | - Olivia R Carroll
- School of Biomedical Sciences & Pharmacy, The University of Newcastle Callaghan, NSW, 2308, Australia
- Hunter Medical Research Institute, New Lambton Heights, NSW, Australia
| | - Phillip Jobling
- School of Biomedical Sciences & Pharmacy, The University of Newcastle Callaghan, NSW, 2308, Australia
- Hunter Medical Research Institute, New Lambton Heights, NSW, Australia
| | - Jay C Horvat
- School of Biomedical Sciences & Pharmacy, The University of Newcastle Callaghan, NSW, 2308, Australia
- Hunter Medical Research Institute, New Lambton Heights, NSW, Australia
| | - Melissa A Tadros
- School of Biomedical Sciences & Pharmacy, The University of Newcastle Callaghan, NSW, 2308, Australia.
- Hunter Medical Research Institute, New Lambton Heights, NSW, Australia.
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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] [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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3
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Sheng G, Chu H, Duan H, Wang W, Tian N, Liu D, Sun H, Sun Z. LRRC25 Inhibits IFN-γ Secretion by Microglia to Negatively Regulate Anti-Tuberculosis Immunity in Mice. Microorganisms 2023; 11:2500. [PMID: 37894158 PMCID: PMC10608824 DOI: 10.3390/microorganisms11102500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 09/30/2023] [Accepted: 10/02/2023] [Indexed: 10/29/2023] Open
Abstract
BACKGROUND Leucine-rich repeat-containing protein-25 (LRRC25) can degrade the ISG15 gene in virus-infected cells and prevent overactivation of the type Ⅰ IFN pathway. However, the role of LRRC25 in bacterial infection is still unclear. In this pursuit, the present study aimed to explore the regulatory role and mechanism of LRRC25 in microglia infected with Mycobacterium tuberculosis in a mouse model. METHODS Q-PCR, WB, and cell immunofluorescence were employed to observe the change in LRRC25 in BV2 cells infected by H37Rv. Additionally, siRNA was designed to target the LRRC25 to inhibit its expression in BV2 cells. Flow cytometry and laser confocal imaging were used to observe the infection of BV2 cells after LRRC25 silencing. Q-PCR and ELISA were used to determine the changes in IFN-γ and ISG15 in the culture supernatant of each group. RESULTS Following H37Rv infection, it was observed that the expression of LRRC25 was upregulated. Upon silencing LRRC25, the proportion of BV2 cells infected by H37Rv decreased significantly. ELISA analysis showed that IFN-γ and ISG15 levels in cell culture supernatant decreased after H37Rv infection, while they significantly increased after LRRC25 silencing. CONCLUSIONS This study provides evidence that LRRC25 is the key negative regulator of microglial anti-Mtb immunity. It exerts its function by degrading free ISG15 and inhibiting the secretion of IFN-γ, thereby improving the anti-Mtb immunity of BV2 cells.
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Affiliation(s)
- Gang Sheng
- Beijing Chest Hospital Affiliated to Capital Medical University, Beijing 100000, China; (G.S.); (H.C.); (W.W.); (N.T.); (D.L.)
| | - Hongqian Chu
- Beijing Chest Hospital Affiliated to Capital Medical University, Beijing 100000, China; (G.S.); (H.C.); (W.W.); (N.T.); (D.L.)
- Beijing Thoracic Tumor and Tuberculosis Institute, Beijing 100000, China;
| | - Huijuan Duan
- Beijing Thoracic Tumor and Tuberculosis Institute, Beijing 100000, China;
| | - Wenjing Wang
- Beijing Chest Hospital Affiliated to Capital Medical University, Beijing 100000, China; (G.S.); (H.C.); (W.W.); (N.T.); (D.L.)
| | - Na Tian
- Beijing Chest Hospital Affiliated to Capital Medical University, Beijing 100000, China; (G.S.); (H.C.); (W.W.); (N.T.); (D.L.)
| | - Dingyi Liu
- Beijing Chest Hospital Affiliated to Capital Medical University, Beijing 100000, China; (G.S.); (H.C.); (W.W.); (N.T.); (D.L.)
| | - Hong Sun
- Beijing Chest Hospital Affiliated to Capital Medical University, Beijing 100000, China; (G.S.); (H.C.); (W.W.); (N.T.); (D.L.)
- Beijing Thoracic Tumor and Tuberculosis Institute, Beijing 100000, China;
| | - Zhaogang Sun
- Beijing Chest Hospital Affiliated to Capital Medical University, Beijing 100000, China; (G.S.); (H.C.); (W.W.); (N.T.); (D.L.)
- Beijing Thoracic Tumor and Tuberculosis Institute, Beijing 100000, China;
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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: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [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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Bourget C, Adams KV, Morshead CM. Reduced microglia activation following metformin administration or microglia ablation is sufficient to prevent functional deficits in a mouse model of neonatal stroke. J Neuroinflammation 2022; 19:146. [PMID: 35705953 PMCID: PMC9199194 DOI: 10.1186/s12974-022-02487-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Accepted: 04/29/2022] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Neonatal stroke is a devastating insult that can lead to life-long impairments. In response to hypoxic-ischaemic injury, there is loss of neurons and glia as well as a neuroinflammatory response mediated by resident immune cells, including microglia and astrocytes, which can exacerbate damage. Administration of the antidiabetic drug metformin has been shown to improve functional outcomes in preclinical models of brain injury and the cellular basis for metformin-mediated recovery is unknown. Given metformin's demonstrated anti-inflammatory properties, we investigated its role in regulating the microglia activation and used a microglia ablation strategy to investigate the microglia-mediated outcomes in a mouse model of neonatal stroke. METHODS Hypoxia-ischaemia (H-I) was performed on post-natal day 8. Metformin was administered for one week, starting one day after injury. Immunohistochemistry was used to examine the spatiotemporal response of microglia and astrocytes after hypoxia-ischaemia, with or without metformin treatment. To evaluate the effects of microglia depletion after hypoxia-ischaemia, we delivered Plexxikon 5622 for 1 or 2 weeks post-injury. The regional pattern of microglia and astrocyte depletion was assessed through immunohistochemistry. Motor behaviour was assessed with the righting reflex, hindlimb suspension, grip strength and cylinder tests. RESULTS Herein, we revealed a spatiotemporally regulated response of microglia and astrocytes after hypoxia-ischaemia. Metformin treatment after hypoxia-ischaemia had no effect on microglia number and proliferation, but significantly reduced microglia activation in all regions examined, concomitant with improved behavioural outcomes in injured mice. Plexxikon 5622 treatment successfully ablated microglia, resulting in a > 90% depletion in microglia in the neonatal brain. Microglia rapidly repopulated upon treatment cessation of Plexxikon. Most interesting, microglia ablation was sufficient to reduce functional deficits after hypoxia-ischaemia, mimicking the effects of 1 week of metformin treatment post-injury. CONCLUSION These results highlight the importance of regulating the neuroinflammatory response after neonatal stroke to promote recovery.
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Affiliation(s)
- Clara Bourget
- Institute of Medical Sciences, University of Toronto, Toronto, M5S1A8, Canada
| | - Kelsey V Adams
- Institute of Medical Sciences, University of Toronto, Toronto, M5S1A8, Canada
| | - Cindi M Morshead
- Institute of Medical Sciences, University of Toronto, Toronto, M5S1A8, Canada.
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College Street, Room 1006, Toronto, ON, M5S3E1, Canada.
- Division of Anatomy, Department of Surgery, University of Toronto, Toronto, M5S1A8, Canada.
- Institute of Biomedical Engineering, University of Toronto, Toronto, M5S3E1, Canada.
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6
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Carroll JA, Race B, Williams K, Striebel JF, Chesebro B. Innate immune responses after stimulation with Toll-like receptor agonists in ex vivo microglial cultures and an in vivo model using mice with reduced microglia. J Neuroinflammation 2021; 18:194. [PMID: 34488805 PMCID: PMC8419892 DOI: 10.1186/s12974-021-02240-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 08/14/2021] [Indexed: 12/02/2022] Open
Abstract
Background Past experiments studying innate immunity in the central nervous system (CNS) utilized microglia obtained from neonatal mouse brain, which differ developmentally from adult microglia. These differences might impact our current understanding of the role of microglia in CNS development, function, and disease. Methods Cytokine protein secretion was compared in ex vivo P3 and adult microglial cultures after exposure to agonists for three different toll-like receptors (TLR4, lipopolysaccharide [LPS]; TLR7, imiquimod [IMQ]; and TLR9, CpG Oligodeoxynucleotide [CpG-ODN] 1585). In addition, changes in inflammatory gene expression in ex vivo adult microglia in response to the TLR agonists was assessed. Furthermore, in vivo experiments evaluated changes in gene expression associated with inflammation and TLR signaling in brains of mice with or without treatment with PLX5622 to reduce microglia. Results Ex vivo adult and P3 microglia increased cytokine secretion when exposed to TLR4 agonist LPS and to TLR7 agonist IMQ. However, adult microglia decreased expression of numerous genes after exposure to TLR 9 agonist CpG-ODN 1585. In contrast, in vivo studies indicated a core group of inflammatory and TLR signaling genes increased when each of the TLR agonists was introduced into the CNS. Reducing microglia in the brain led to decreased expression of various inflammatory and TLR signaling genes. Mice with reduced microglia showed extreme impairment in upregulation of genes after exposure to TLR7 agonist IMQ. Conclusions Cultured adult microglia were more reactive than P3 microglia to LPS or IMQ exposure. In vivo results indicated microglial influences on neuroinflammation were agonist specific, with responses to TLR7 agonist IMQ more dysregulated in mice with reduced microglia. Thus, TLR7-mediated innate immune responses in the CNS appeared more dependent on the presence of microglia. Furthermore, partial responses to TLR4 and TLR9 agonists in mice with reduced microglia suggested other cell types in the CNS can compensate for their absence. Supplementary Information The online version contains supplementary material available at 10.1186/s12974-021-02240-w.
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Affiliation(s)
- James A Carroll
- Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 903 South Fourth Street, Hamilton, MT, 59840, USA.
| | - Brent Race
- Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 903 South Fourth Street, Hamilton, MT, 59840, USA
| | - Katie Williams
- Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 903 South Fourth Street, Hamilton, MT, 59840, USA
| | - James F Striebel
- Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 903 South Fourth Street, Hamilton, MT, 59840, USA
| | - Bruce Chesebro
- Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 903 South Fourth Street, Hamilton, MT, 59840, USA
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Parolisi R, Montarolo F, Pini A, Rovelli S, Cattaneo A, Bertolotto A, Buffo A, Bollati V, Boda E. Exposure to fine particulate matter (PM 2.5) hampers myelin repair in a mouse model of white matter demyelination. Neurochem Int 2021; 145:104991. [PMID: 33587955 DOI: 10.1016/j.neuint.2021.104991] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 01/05/2021] [Accepted: 02/10/2021] [Indexed: 12/31/2022]
Abstract
Epidemiological studies show a strong association between exposure to air pollution - and particularly to particulate matter (PM) -, increased prevalence of Multiple Sclerosis (MS) and higher rates of hospital admissions for MS and MS relapses. Besides having immunomodulatory effects and sustaining a systemic oxidative-inflammatory response, PM may participate in MS pathogenesis by targeting also Central Nervous System (CNS)-specific processes, such as myelin repair. Here we show that, in a mouse model of lysolecithin-induced demyelination of the subcortical white matter, post-injury exposure to fine PM hampers remyelination, disturbs oligodendroglia differentiation dynamics and promotes astroglia and microglia reactivity. These findings support the view that exposure to fine PM can contribute to demyelinating pathologies by targeting the endogenous regenerative capability of the CNS tissue.
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Affiliation(s)
- Roberta Parolisi
- Department of Neuroscience Rita Levi-Montalcini, University of Turin, Italy; Neuroscience Institute Cavalieri Ottolenghi (NICO), University of Turin, Regione Gonzole, 10, 10043, Orbassano (Turin), Italy
| | - Francesca Montarolo
- Neuroscience Institute Cavalieri Ottolenghi (NICO), University of Turin, Regione Gonzole, 10, 10043, Orbassano (Turin), Italy; Neurobiology Unit, Neurology-CReSM (Regional Referring Center of Multiple Sclerosis), AOU San Luigi Gonzaga, Regione Gonzole 10, 10043, Orbassano, Italy; Department of Molecular Biotechnology and Health Sciences, University of Turin, via Nizza 52, 10126, Turin, Italy
| | - Alessandro Pini
- Department of Clinical and Experimental Medicine, University of Florence, Viale Pieraccini 6, 50139, Florence, Italy
| | - Sabrina Rovelli
- Department of Science and High Technology, University of Insubria, 22100, Como, Italy
| | - Andrea Cattaneo
- Department of Science and High Technology, University of Insubria, 22100, Como, Italy
| | - Antonio Bertolotto
- Neuroscience Institute Cavalieri Ottolenghi (NICO), University of Turin, Regione Gonzole, 10, 10043, Orbassano (Turin), Italy; Neurobiology Unit, Neurology-CReSM (Regional Referring Center of Multiple Sclerosis), AOU San Luigi Gonzaga, Regione Gonzole 10, 10043, Orbassano, Italy
| | - Annalisa Buffo
- Department of Neuroscience Rita Levi-Montalcini, University of Turin, Italy; Neuroscience Institute Cavalieri Ottolenghi (NICO), University of Turin, Regione Gonzole, 10, 10043, Orbassano (Turin), Italy
| | - Valentina Bollati
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - Enrica Boda
- Department of Neuroscience Rita Levi-Montalcini, University of Turin, Italy; Neuroscience Institute Cavalieri Ottolenghi (NICO), University of Turin, Regione Gonzole, 10, 10043, Orbassano (Turin), Italy.
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Hetze S, Sure U, Schedlowski M, Hadamitzky M, Barthel L. Rodent Models to Analyze the Glioma Microenvironment. ASN Neuro 2021; 13:17590914211005074. [PMID: 33874781 PMCID: PMC8060738 DOI: 10.1177/17590914211005074] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 02/28/2021] [Accepted: 03/01/2021] [Indexed: 12/14/2022] Open
Abstract
Animal models are still indispensable for understanding the basic principles of glioma development and invasion. Preclinical approaches aim to analyze the treatment efficacy of new drugs before translation into clinical trials is possible. Various animal disease models are available, but not every approach is useful for addressing specific questions. In recent years, it has become increasingly evident that the tumor microenvironment plays a key role in the nature of glioma. In addition to providing an overview, this review evaluates available rodent models in terms of usability for research on the glioma microenvironment.
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Affiliation(s)
- Susann Hetze
- Department of Neurosurgery, University Hospital of
Essen, Essen, Germany
- Institute of Medical Psychology and Behavioral
Immunobiology, University Hospital of Essen, Essen, Germany
| | - Ulrich Sure
- Department of Neurosurgery, University Hospital of
Essen, Essen, Germany
| | - Manfred Schedlowski
- Institute of Medical Psychology and Behavioral
Immunobiology, University Hospital of Essen, Essen, Germany
- Department of Clinical Neuroscience, Osher Center for
Integrative Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Martin Hadamitzky
- Institute of Medical Psychology and Behavioral
Immunobiology, University Hospital of Essen, Essen, Germany
| | - Lennart Barthel
- Department of Neurosurgery, University Hospital of
Essen, Essen, Germany
- Institute of Medical Psychology and Behavioral
Immunobiology, University Hospital of Essen, Essen, Germany
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Bobermin LD, Roppa RHA, Gonçalves CA, Quincozes-Santos A. Ammonia-Induced Glial-Inflammaging. Mol Neurobiol 2020; 57:3552-3567. [DOI: 10.1007/s12035-020-01985-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 06/08/2020] [Indexed: 12/13/2022]
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10
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Carroll JA, Race B, Williams K, Striebel J, Chesebro B. RNA-seq and network analysis reveal unique glial gene expression signatures during prion infection. Mol Brain 2020; 13:71. [PMID: 32381108 PMCID: PMC7206698 DOI: 10.1186/s13041-020-00610-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 04/24/2020] [Indexed: 02/01/2023] Open
Abstract
Background Prion diseases and prion-like disorders, including Alzheimer’s disease and Parkinson’s disease, are characterized by gliosis and accumulation of misfolded aggregated host proteins. Ablating microglia in prion-infected brain by treatment with the colony-stimulating factor-1 receptor (CSF-1R) inhibitor, PLX5622, increased accumulation of misfolded prion protein and decreased survival time. Methods To better understand the role of glia during neurodegeneration, we used RNA-seq technology, network analysis, and hierarchical cluster analysis to compare gene expression in brains of prion-infected versus mock-inoculated mice. Comparisons were also made between PLX5622-treated prion-infected mice and untreated prion-infected mice to assess mechanisms involved in disease acceleration in the absence of microglia. Results RNA-seq and network analysis suggested that microglia responded to prion infection through activation of integrin CD11c/18 and did not adopt the expression signature associated with other neurodegenerative disease models. Instead, microglia acquired an alternative molecular signature late in the disease process. Furthermore, astrocytes expressed a signature pattern of genes which appeared to be specific for prion diseases. Comparisons were also made with prion-infected mice treated with PLX5622 to assess the impact of microglia ablation on astrocyte gene expression during prion infection. In the presence of microglia, a unique mix of transcripts associated with A1- and A2-reactive astrocytes was increased in brains of prion-infected mice. After ablation of microglia, this reactive astrocyte expression pattern was enhanced. Thus, after prion infection, microglia appeared to decrease the overall A1/A2-astrocyte responses which might contribute to increased survival after infection. Conclusions RNA-seq analysis indicated dysregulation of over 300 biological processes within the CNS during prion disease. Distinctive microglia- and astrocyte-associated expression signatures were identified during prion infection. Furthermore, astrogliosis and the unique astrocyte-associated expression signature were independent of microglial influences. Astrogliosis and the unique astrocyte-associated gene expression pattern were increased when microglia were ablated. Our findings emphasize the potential existence of alternative pathways for activating the A1/A2 paradigm in astrocytes during neurodegenerative disease.
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Affiliation(s)
- James A Carroll
- Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 903 South Fourth Street, Hamilton, MT, 59840, USA.
| | - Brent Race
- Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 903 South Fourth Street, Hamilton, MT, 59840, USA
| | - Katie Williams
- Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 903 South Fourth Street, Hamilton, MT, 59840, USA
| | - James Striebel
- Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 903 South Fourth Street, Hamilton, MT, 59840, USA
| | - Bruce Chesebro
- Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 903 South Fourth Street, Hamilton, MT, 59840, USA
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11
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De Dios R, Nguyen L, Ghosh S, McKenna S, Wright CJ. CpG-ODN-mediated TLR9 innate immune signalling and calcium dyshomeostasis converge on the NFκB inhibitory protein IκBβ to drive IL1α and IL1β expression. Immunology 2020; 160:64-77. [PMID: 32064589 DOI: 10.1111/imm.13182] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 01/31/2020] [Accepted: 02/11/2020] [Indexed: 12/24/2022] Open
Abstract
Sterile inflammation contributes to many pathological states associated with mitochondrial injury. Mitochondrial injury disrupts calcium homeostasis and results in the release of CpG-rich mitochondrial DNA. The role of CpG-stimulated TLR9 innate immune signalling and sterile inflammation is well studied; however, how calcium dyshomeostasis affects this signalling is unknown. Therefore, we interrogated the relationship beτween intracellular calcium and CpG-induced TLR9 signalling in murine macrophages. We found that CpG-ODN-induced NFκB-dependent IL1α and IL1β expression was significantly attenuated by both calcium chelation and calcineurin inhibition, a finding mediated by inhibition of degradation of the NFκB inhibitory protein IκBβ. In contrast, calcium ionophore exposure increased CpG-induced IκBβ degradation and IL1α and IL1β expression. These results demonstrate that through its effect on IκBβ degradation, increased intracellular Ca2+ drives a pro-inflammatory TLR9-mediated innate immune response. These results have implications for the study of innate immune signalling downstream of mitochondrial stress and injury.
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Affiliation(s)
- Robyn De Dios
- Section of Neonatology, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, USA
| | - Leanna Nguyen
- Section of Neonatology, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, USA
| | - Sankar Ghosh
- Department of Microbiology & Immunology, College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Sarah McKenna
- Section of Neonatology, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, USA
| | - Clyde J Wright
- Section of Neonatology, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, USA
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12
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Manangeeswaran M, Lewkowicz AP, Israely T, Ireland DDC, Verthelyi D. CpG Oligonucleotides Protect Mice From Alphavirus Encephalitis: Role of NK Cells, Interferons, and TNF. Front Immunol 2020; 11:237. [PMID: 32133008 PMCID: PMC7040238 DOI: 10.3389/fimmu.2020.00237] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 01/29/2020] [Indexed: 12/26/2022] Open
Abstract
Arboviruses including alphavirus are responsible for most emerging infectious diseases worldwide. Recent outbreaks of chikungunya virus serve as a stark reminder to their pathogenic potential. There are no vaccines or therapeutics currently available to contain alphavirus outbreaks. In this study we evaluated the effect of immunomodulatory CpG ODN on the clinical progression of neurotropic Sindbis virus infection. Neonatal C57Bl-6 mice challenged with Sindbis virus AR339 (25 PFU Subcutaneous) infect neurons in the CNS leading to the development of ataxia, seizures, paralysis, and death. We show that systemic administration of CpG ODN modulates the cytokine and chemokine gene expression levels in the CNS and ultimately protects neonatal mice from lethal neurotropic infection. The protection conferred by CpG ODN is controlled by innate immune response and T and B cells were dispensable. Further, protection required Type I, Type II interferons, and TNF as well as functional NK cells, but did not involve iNOS. This study confirms that administration of innate immune modulators can be used as a strategy to boost host innate immune responses and protect against neurotropic viruses reducing their pathogenic footprint.
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Affiliation(s)
- Mohanraj Manangeeswaran
- Division of Biotechnology Review and Research-III, Office of Biotechnology Products, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD, United States
| | - Aaron P Lewkowicz
- Division of Biotechnology Review and Research-III, Office of Biotechnology Products, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD, United States
| | - Tomer Israely
- Division of Biotechnology Review and Research-III, Office of Biotechnology Products, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD, United States
| | - Derek D C Ireland
- Division of Biotechnology Review and Research-III, Office of Biotechnology Products, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD, United States
| | - Daniela Verthelyi
- Division of Biotechnology Review and Research-III, Office of Biotechnology Products, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD, United States
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13
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Microglial Function in the Effects of Early-Life Stress on Brain and Behavioral Development. J Clin Med 2020; 9:jcm9020468. [PMID: 32046333 PMCID: PMC7074320 DOI: 10.3390/jcm9020468] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Revised: 01/30/2020] [Accepted: 02/05/2020] [Indexed: 02/06/2023] Open
Abstract
The putative effects of early-life stress (ELS) on later behavior and neurobiology have been widely investigated. Recently, microglia have been implicated in mediating some of the effects of ELS on behavior. In this review, findings from preclinical and clinical literature with a specific focus on microglial alterations induced by the exposure to ELS (i.e., exposure to behavioral stressors or environmental agents and infection) are summarized. These studies were utilized to interpret changes in developmental trajectories based on the time at which the stress occurred, as well as the paradigm used. ELS and microglial alterations were found to be associated with a wide array of deficits including cognitive performance, memory, reward processing, and processing of social stimuli. Four general conclusions emerged: (1) ELS interferes with microglial developmental programs, including their proliferation and death and their phagocytic activity; (2) this can affect neuronal and non-neuronal developmental processes, which are dynamic during development and for which microglial activity is instrumental; (3) the effects are extremely dependent on the time point at which the investigation is carried out; and (4) both pre- and postnatal ELS can prime microglial reactivity, indicating a long-lasting alteration, which has been implicated in behavioral abnormalities later in life.
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14
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Zanno AE, Romer MA, Fox L, Golden T, Jaeckle-Santos L, Simmons RA, Grinspan JB. Reducing Th2 inflammation through neutralizing IL-4 antibody rescues myelination in IUGR rat brain. J Neurodev Disord 2019; 11:34. [PMID: 31839002 PMCID: PMC6913005 DOI: 10.1186/s11689-019-9297-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 11/11/2019] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Intrauterine growth restriction (IUGR) is a common complication of pregnancy and is associated with significant neurological deficits in infants, including white matter damage. Previous work using an animal model of IUGR has demonstrated that IUGR rats exhibit neurobehavioral deficits and developmental delays in oligodendrocyte maturation and myelination, but the mechanisms which cause this delay are unknown. Inflammation may be an important etiological factor in IUGR and has been recognized as playing a fundamental role in the pathogenesis of myelin disorders, including cerebral palsy. METHODS To create the model, the uterine arteries of pregnant rats were ligated at embryonic day 15. Rats delivered spontaneously. Cytokine and chemokine expression was evaluated at one prenatal and three postnatal time points, and myelin protein expression and oligodendrocyte cell numbers were evaluated by several methods at postnatal day 14. IL-4 was identified as a potential inhibitor of myelination, and rat pups were injected with IL-4 function blocking antibody from postnatal days 1-5 and myelination was assessed. RESULTS Here, we show a novel mechanism of white matter injury. IUGR induces an exaggerated Th2 response in the developing rat brain, including upregulation of several Th2 cytokines. Of these, IL-4 is significantly increased during the period corresponding to robust developmental myelination. We show that neutralizing IL-4 antibody therapy given in the newborn period ameliorates inflammation and restores myelin protein expression and oligodendrocyte cell number in the IUGR brain to control levels, demonstrating a novel role for Th2 responses and IL-4 in IUGR and white matter injury. In addition, IL-4 directly affects oligodendrocytes in vitro decreasing differentiation. CONCLUSIONS In this study, we have identified inflammation as a factor in the decrease in myelin seen in an animal model of IUGR. IL-4, an inflammatory protein often thought to be protective in the adult, is specifically increased, and treatment of these animals to prevent this increase ameliorates white matter damage. Our results suggest that the immune system plays a role in IUGR that is different in the perinatal period than in the adult and preventing this exaggerated Th2 response may be a potential therapeutic target.
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Affiliation(s)
- Allison E. Zanno
- Department of Pediatrics, Children’s Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA USA
| | - Micah A. Romer
- Department of Neurology, Children’s Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, 516D Abramson Center, 3615 Civic Center Blvd, Philadelphia, PA 19104 USA
| | - Lauren Fox
- Department of Pediatrics, Children’s Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA USA
| | - Thea Golden
- Department of Pediatrics, Children’s Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA USA
| | - Lane Jaeckle-Santos
- Department of Pediatrics, Children’s Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA USA
| | - Rebecca A. Simmons
- Department of Pediatrics, Children’s Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA USA
| | - Judith B. Grinspan
- Department of Neurology, Children’s Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, 516D Abramson Center, 3615 Civic Center Blvd, Philadelphia, PA 19104 USA
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15
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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 PMCID: PMC6663660 DOI: 10.1016/j.ijdevneu.2019.01.007] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [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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16
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Ahmad SF, Ansari MA, Nadeem A, Bakheet SA, AL-Ayadhi LY, Alotaibi MR, Alhoshani AR, Alshammari MA, Attia SM. Dysregulation of T cell immunoglobulin and mucin domain 3 (TIM-3) signaling in peripheral immune cells is associated with immune dysfunction in autistic children. Mol Immunol 2019; 106:77-86. [DOI: 10.1016/j.molimm.2018.12.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 11/26/2018] [Accepted: 12/19/2018] [Indexed: 02/05/2023]
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17
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Ni P, Dong H, Wang Y, Zhou Q, Xu M, Qian Y, Sun J. IL-17A contributes to perioperative neurocognitive disorders through blood-brain barrier disruption in aged mice. J Neuroinflammation 2018; 15:332. [PMID: 30501622 PMCID: PMC6267879 DOI: 10.1186/s12974-018-1374-3] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 11/19/2018] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND Perioperative neurocognitive disorders (PND) occur frequently after surgery, especially in aged patients. Surgery-induced neuroinflammation and blood-brain barrier (BBB) dysfunction play a crucial role in the pathogenesis of PND. Interleukin-17A (IL-17A) increases after surgical stress and will be involved in BBB dysfunction. However, the effect of IL-17A on BBB function during PND remains poorly understood. METHODS Male wild-type C57BL/6J mice (15 months old) received tibial fracture surgery and fixation to establish the PND model. All the mice were injected intraperitoneally with an IL-17A-neutralizing antibody (Abs) or isotype-control Abs 30 min before tibial fracture surgery. Animal behaviour tests conducted 24 h after surgery included the contextual fear conditioning and Y maze tests. Serum and hippocampus IL-17A levels and hippocampus IL-6 and IL-1β levels were detected by ELISA. BBB function was detected by Evans blue (EB) test. Hippocampus matrix metalloproteinase-2 (MMP-2)- and MMP-9-positive cells were detected by immunohistochemistry. Hippocampus albumin, occludin, claudin-5 and IL-17A receptors were detected by Western blot. For the in vitro experiment, bEnd.3 cells were incubated with IL-17A. Cell IL-17A receptors were detected by immunofluorescence. Cellular MMP-2, MMP-9, occludin, and claudin-5 were detected by Western blot. RESULTS Tibial fracture surgery promoted memory impairment, increased levels of IL-17A and IL-17A receptors, inflammatory factor production and BBB dysfunction. IL-17A Abs inhibited this effect, including improving memory function, decreasing inflammatory factor production and alleviating BBB disruption, indicated by decreased tight junctions (TJs) and increased MMPs after surgery. The in vitro study suggested that recombinant IL-17A could upregulate the expression of IL-17A receptors, decrease TJs and increase the level of MMPs in bEnd.3 cells. CONCLUSIONS Our results suggested that IL-17A-promoted BBB disruption might play an important role in the pathogenesis of PND.
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Affiliation(s)
- Pengfei Ni
- Department of Anesthesiology, The First Affiliated Hospital of Nanjing Medical University, Jiangsu, 210029, People's Republic of China
| | - Hongquan Dong
- Department of Anesthesiology, The First Affiliated Hospital of Nanjing Medical University, Jiangsu, 210029, People's Republic of China
| | - Yiwei Wang
- Department of Anesthesiology, The First Affiliated Hospital of Nanjing Medical University, Jiangsu, 210029, People's Republic of China
| | - Qin Zhou
- Department of Anesthesiology, The First Affiliated Hospital of Nanjing Medical University, Jiangsu, 210029, People's Republic of China
| | - Mengmeng Xu
- Department of Anesthesiology, The First Affiliated Hospital of Nanjing Medical University, Jiangsu, 210029, People's Republic of China
| | - Yanning Qian
- Department of Anesthesiology, The First Affiliated Hospital of Nanjing Medical University, Jiangsu, 210029, People's Republic of China
| | - Jie Sun
- Department of Anesthesiology, The First Affiliated Hospital of Nanjing Medical University, Jiangsu, 210029, People's Republic of China.
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18
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Embryonic Neocortical Microglia Express Toll-Like Receptor 9 and Respond to Plasmid DNA Injected into the Ventricle: Technical Considerations Regarding Microglial Distribution in Electroporated Brain Walls. eNeuro 2018; 5:eN-MNT-0312-18. [PMID: 30627652 PMCID: PMC6325556 DOI: 10.1523/eneuro.0312-18.2018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 10/19/2018] [Accepted: 10/27/2018] [Indexed: 12/25/2022] Open
Abstract
Microglia, the resident immune cells in the CNS, play multiple roles during development. In the embryonic cerebral wall, microglia modulate the functions of neural stem/progenitor cells through their distribution in regions undergoing cell proliferation and/or differentiation. Previous studies using CX3CR1-GFP transgenic mice demonstrated that microglia extensively survey these regions. To simultaneously visualize microglia and neural-lineage cells that interact with each other, we applied the in utero electroporation (IUE) technique, which has been widely used for gene-transfer in neurodevelopmental studies, to CX3CR1-GFP mice (males and females). However, we unexpectedly faced a technical problem: although microglia are normally distributed homogeneously throughout the mid-embryonic cortical wall with only limited luminal entry, the intraventricular presence of exogenously derived plasmid DNAs induced microglia to accumulate along the apical surface of the cortex and aggregate in the choroid plexus. This effect was independent of capillary needle puncture of the brain wall or application of electrical pulses. The microglial response occurred at plasmid DNA concentrations lower than those routinely used for IUE, and was mediated by activation of Toll-like receptor 9 (TLR9), an innate immune sensor that recognizes unmethylated cytosine-phosphate guanosine motifs abundant in microbial DNA. Administration of plasmid DNA together with oligonucleotide 2088, the antagonist of TLR9, partially restored the dispersed intramural localization of microglia and significantly decreased luminal accumulation of these cells. Thus, via TLR9, intraventricular plasmid DNA administration causes aberrant distribution of embryonic microglia, suggesting that the behavior of microglia in brain primordia subjected to IUE should be carefully interpreted.
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19
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Hu S, Liu Q, Zang S, Zhang Z, Wang J, Cai X, He X. Microglia Are Derived from Peripheral Blood Mononuclear Cells After Pseudorabies Infection in Mice. Viral Immunol 2018; 31:596-604. [PMID: 30339053 DOI: 10.1089/vim.2018.0064] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Pseudorabies virus (PRV) can spread along the peripheral nerves near the site of infection in the animals, and gradually migrates into the central nervous system, where it leads to the development of brain lesions. The aim of this study was to investigate the dynamics of microglia after PRV inoculation. A mouse model inoculated with PRV was established to study the interactions between PRV and microglia, microglial recruitment, and polarization effects. The mice were subcutaneously inoculated with different doses of PRV-Bartha K61 vaccine strain. The obtained results showed that mouse mortality rates increased with the applied doses of virus, and brain lesions, located in the brain tail and brain stem, were observed in each investigated group. Inflammatory cells were shown to infiltrate through the vasculature into perivascular cuff, and the number of microglia was increased as well. Mouse group treated with a medium infection dose demonstrated a high survival rate while developing serious brain lesions, and therefore, this dose was selected for further experiments. Immunohistochemistry, flow cytometry, and confocal laser scanning microscopy were used to analyze PRV-microglia interactions. After PRV inoculation, proliferating cell nuclear antigen (Pcna) and Iba1 double-positive cells were observed in the brain lesions, together with the activated microglia, suggesting that PRV can induce microglial proliferation and activation. Furthermore, 5-bromo-deoxy-uridine (BrdU) labeling demonstrated that microglial cells did not proliferate in situ and the proliferating cells originated from peripheral blood monocytes, mainly from the inflammatory monocytes (Ly6Chigh). In addition, microglia polarized into both M1 and M2 phenotypes by PRV infection. The results obtained in this study may help understand the development of pseudorabies infection and help improve the treatment, by recruiting and enhancing immune response.
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Affiliation(s)
- Shouping Hu
- National Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute , Chinese Academy of Agricultural Sciences, Harbin, China
| | - Qiang Liu
- National Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute , Chinese Academy of Agricultural Sciences, Harbin, China
| | - Sufang Zang
- National Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute , Chinese Academy of Agricultural Sciences, Harbin, China
| | - Zhuo Zhang
- National Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute , Chinese Academy of Agricultural Sciences, Harbin, China
| | - Jingfei Wang
- National Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute , Chinese Academy of Agricultural Sciences, Harbin, China
| | - Xuehui Cai
- National Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute , Chinese Academy of Agricultural Sciences, Harbin, China
| | - Xijun He
- National Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute , Chinese Academy of Agricultural Sciences, Harbin, China
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20
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Song S, Wang S, Pigott VM, Jiang T, Foley LM, Mishra A, Nayak R, Zhu W, Begum G, Shi Y, Carney KE, Hitchens TK, Shull GE, Sun D. Selective role of Na + /H + exchanger in Cx3cr1 + microglial activation, white matter demyelination, and post-stroke function recovery. Glia 2018; 66:2279-2298. [PMID: 30043461 DOI: 10.1002/glia.23456] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 03/27/2018] [Accepted: 04/24/2018] [Indexed: 12/22/2022]
Abstract
Na+ /H+ exchanger (NHE1) activation is required for multiple microglial functions. We investigated effects of selective deletion of microglial Nhe1 in Cx3cr1-CreER ;Nhe1f/f mice on neuroinflammation and tissue repair after ischemic stroke. Infarct volume was similar in corn oil or tamoxifen (Tam)-treated mice at 48 hr and 14 days post-stroke. However, the Tam-treated mice showed significantly higher survival rate and faster neurological function recovery during day 1-14 post-stroke. Deletion of microglial Nhe1 prevented the elevation of CD11b+ /CD45low-med microglia in the ischemic hemisphere at day 3 post-stroke, but stimulated expression of Ym1, CD68, TGF-β, IL-10, decreased expression of CD86 and IL-1β, and reduced GFAP+ reactive astrocytes. Moreover, at day 14 post-stroke, enhanced white matter myelination was detected in the microglial Nhe1 deleted mice. In comparison, neuronal Nhe1-null mice (the CamKII-Cre+/- ;Nhe1f/f mice) showed a significant reduction in both acute and subacute infarct volume, along with increased survival rate and moderate neurological function recovery. However, these neuronal Nhe1-null mice did not exhibit reduced activation of CD11b+ /CD45low-med microglia or CD11b+ /CD45hi macrophages in the ischemic brains, and they exhibited no reductions in white matter lesions. Taken together, this study demonstrated that deletion of microglial and neuronal Nhe1 had differential effects on ischemic brain damage. Microglial NHE1 is involved in pro-inflammatory responses during post-stroke brain tissue repair. In contrast, neuronal NHE1 activation is directly associated with the acute ischemic neuronal injury but not inflammation. Our study reveals that NHE1 protein is a potential therapeutic target critical for differential regulation of ischemic neuronal injury, demyelination and tissue repair.
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Affiliation(s)
- Shanshan Song
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213.,Pittsburgh Institute for Neurodegenerative Disorders, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213
| | - Shaoxia Wang
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213.,Tianjin State Key Laboratory of Modern Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, 300193, China
| | - Victoria M Pigott
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213.,Pittsburgh Institute for Neurodegenerative Disorders, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213
| | - Tong Jiang
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213.,Pittsburgh Institute for Neurodegenerative Disorders, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213
| | - Lesley M Foley
- Animal Imaging Center, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213
| | - Abhishek Mishra
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213
| | - Rachana Nayak
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213
| | - Wen Zhu
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213
| | - Gulnaz Begum
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213.,Pittsburgh Institute for Neurodegenerative Disorders, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213
| | - Yejie Shi
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213
| | - Karen E Carney
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213
| | - T Kevin Hitchens
- Animal Imaging Center, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213.,Department of Neurobiology, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213
| | - Gary E Shull
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati, Cincinnati, Ohio, 45267
| | - Dandan Sun
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213.,Pittsburgh Institute for Neurodegenerative Disorders, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213.,Veterans Affairs Pittsburgh Health Care System, Geriatric Research, Educational and Clinical Center, Pittsburgh, Pennsylvania
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The microbiota influences cell death and microglial colonization in the perinatal mouse brain. Brain Behav Immun 2018; 67:218-229. [PMID: 28890156 PMCID: PMC5696094 DOI: 10.1016/j.bbi.2017.08.027] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [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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22
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Lameth J, Gervais A, Colin C, Lévêque P, Jay TM, Edeline JM, Mallat M. Acute Neuroinflammation Promotes Cell Responses to 1800 MHz GSM Electromagnetic Fields in the Rat Cerebral Cortex. Neurotox Res 2017; 32:444-459. [PMID: 28578480 DOI: 10.1007/s12640-017-9756-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 05/16/2017] [Accepted: 05/19/2017] [Indexed: 01/08/2023]
Abstract
Mobile phone communications are conveyed by radiofrequency (RF) electromagnetic fields, including pulse-modulated global system for mobile communications (GSM)-1800 MHz, whose effects on the CNS affected by pathological states remain to be specified. Here, we investigated whether a 2-h head-only exposure to GSM-1800 MHz could impact on a neuroinflammatory reaction triggered by lipopolysaccharide (LPS) in 2-week-old or adult rats. We focused on the cerebral cortex in which the specific absorption rate (SAR) of RF averaged 2.9 W/kg. In developing rats, 24 h after GSM exposure, the levels of cortical interleukin-1ß (IL1ß) or NOX2 NADPH oxidase transcripts were reduced by 50 to 60%, in comparison with sham-exposed animals (SAR = 0), as assessed by RT-qPCR. Adult rats exposed to GSM also showed a 50% reduction in the level of IL1ß mRNA, but they differed from developing rats by the lack of NOX2 gene suppression and by displaying a significant growth response of microglial cell processes imaged in anti-Iba1-stained cortical sections. As neuroinflammation is often associated with changes in excitatory neurotransmission, we evaluated changes in expression and phosphorylation of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors in the adult cerebral cortex by Western blot analyses. We found that GSM exposure decreased phosphorylation at two residues on the GluA1 AMPAR subunit (serine 831 and 845). The GSM-induced changes in gene expressions, microglia, and GluA1 phosphorylation did not persist 72 h after RF exposure and were not observed in the absence of LPS pretreatment. Together, our data provide evidence that GSM-1800 MHz can modulate CNS cell responses triggered by an acute neuroinflammatory state.
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Affiliation(s)
- Julie Lameth
- Sorbonne Universités, UPMC Univ Paris 06, INSERM U.1127, CNRS, Institut du Cerveau et de la Moelle épinière (ICM), Hôpital Pitié-Salpêtrière, Bat. ICM, 47 boulevard de l'Hôpital, F-75013, Paris, France
| | - Annie Gervais
- Sorbonne Universités, UPMC Univ Paris 06, INSERM U.1127, CNRS, Institut du Cerveau et de la Moelle épinière (ICM), Hôpital Pitié-Salpêtrière, Bat. ICM, 47 boulevard de l'Hôpital, F-75013, Paris, France
| | - Catherine Colin
- Sorbonne Universités, UPMC Univ Paris 06, INSERM U.1127, CNRS, Institut du Cerveau et de la Moelle épinière (ICM), Hôpital Pitié-Salpêtrière, Bat. ICM, 47 boulevard de l'Hôpital, F-75013, Paris, France
| | - Philippe Lévêque
- Université de Limoges, CNRS, XLIM, UMR 7252, 123 avenue Albert Thomas, F-87000, Limoges, France
| | - Thérèse M Jay
- Physiopathologie des Maladies Psychiatriques, Centre de Psychiatrie et Neurosciences, UMR_S894 INSERM, Université Paris Descartes, 102-108 rue de la Santé, 75014, Paris, France
| | - Jean-Marc Edeline
- Paris Saclay Institute of Neuroscience, Neuro-PSI, UMR 9197 CNRS, Université Paris-Sud, 91405, Orsay cedex, France
| | - Michel Mallat
- Sorbonne Universités, UPMC Univ Paris 06, INSERM U.1127, CNRS, Institut du Cerveau et de la Moelle épinière (ICM), Hôpital Pitié-Salpêtrière, Bat. ICM, 47 boulevard de l'Hôpital, F-75013, Paris, France.
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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: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [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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Cohen S, Ke X, Liu Q, Fu Q, Majnik A, Lane R. Adverse early life environment increases hippocampal microglia abundance in conjunction with decreased neural stem cells in juvenile mice. Int J Dev Neurosci 2016; 55:56-65. [PMID: 27666383 DOI: 10.1016/j.ijdevneu.2016.09.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Revised: 09/20/2016] [Accepted: 09/21/2016] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Adverse maternal lifestyle resulting in adverse early life environment (AELE) increases risks for neuropsychiatric disorders in offspring. Neuropsychiatric disorders are associated with impaired neurogenesis and neuro-inflammation in the hippocampus (HP). Microglia are neuro-inflammatory cells in the brain that regulate neurogenesis via toll-like receptors (TLR). TLR-9 is implicated in neurogenesis inhibition and is responsible for stress-related inflammatory responses. We hypothesized that AELE would increase microglia cell count and increase TLR-9 expression in juvenile mouse HP. These increases in microglia cell count and TLR-9 expression would be associated with decrease neural stem cell count and neuronal cell count. METHODS We developed a mouse model of AELE combining Western diet and a stress environment. Stress environment consisted of random change from embryonic day 13 (E13) to E17 as well as static change in maternal environment from E13 to postnatal day 21(P21). At P21, we measured hippocampal cell numbers of microglia, neural stem cell and neuron, as well as hippocampal TLR-9 expression. RESULTS AELE significantly increased total microglia number and TLR-9 expression in the hippocampus. Concurrently, AELE significantly decreased neural stem cell and neuronal numbers. CONCLUSIONS AELE increased the neuro-inflammatory cellular response in the juvenile HP. We speculate that increased neuro-inflammatory responses may contribute to impaired neurogenesis seen in this model.
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Affiliation(s)
- Susan Cohen
- Division of Neonatology, Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI, United States.
| | - Xingrao Ke
- Division of Neonatology, Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Qiuli Liu
- Division of Neonatology, Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Qi Fu
- Division of Neonatology, Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Amber Majnik
- Division of Neonatology, Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Robert Lane
- Division of Neonatology, Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI, United States
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25
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Suppression of microglia activation after hypoxia-ischemia results in age-dependent improvements in neurologic injury. J Neuroimmunol 2015; 291:18-27. [PMID: 26857490 DOI: 10.1016/j.jneuroim.2015.12.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 12/05/2015] [Accepted: 12/09/2015] [Indexed: 12/14/2022]
Abstract
We previously found increased microglial proliferation and pro-inflammatory cytokine release in infant mice compared to juvenile mice after hypoxia-ischemia (HI). The aim of the current study was to assess for differences in the effect of microglial suppression on HI-induced brain injury in infant and juvenile mice. HI was induced in neonatal (P9) and juvenile (P30) mice and minocycline or vehicle was administered at 2h and 24h post-HI. P9 minocycline-treated mice demonstrated early but transient improvements in neurologic injury, while P30 minocycline-treated mice demonstrated sustained improvements in cerebral atrophy and Morris Water Maze performance at 60days post-HI.
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26
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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: 125] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [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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