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Cao M, Kuthiala S, Jean KJ, Liu HL, Courchesne M, Nygard K, Burns P, Desrochers A, Fecteau G, Faure C, Frasch MG. The Vagus Nerve Regulates Immunometabolic Homeostasis in the Ovine Fetus near Term: The Impact on Terminal Ileum. BIOLOGY 2024; 13:38. [PMID: 38248469 PMCID: PMC10812930 DOI: 10.3390/biology13010038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 01/04/2024] [Accepted: 01/05/2024] [Indexed: 01/23/2024]
Abstract
BACKGROUND Glucosensing elements are widely distributed throughout the body and relay information about circulating glucose levels to the brain via the vagus nerve. However, while anatomical wiring has been established, little is known about the physiological role of the vagus nerve in glucosensing. The contribution of the vagus nerve to inflammation in the fetus is poorly understood. Increased glucose levels and inflammation act synergistically when causing organ injury, but their interplay remains incompletely understood. We hypothesized that vagotomy (Vx) will trigger a rise in systemic glucose levels and this will be enhanced during systemic and organ-specific inflammation. Efferent vagus nerve stimulation (VNS) should reverse this phenotype. METHODS Near-term fetal sheep (n = 57) were surgically prepared using vascular catheters and ECG electrodes as the control and treatment groups (lipopolysaccharide (LPS), Vx + LPS, Vx + LPS + selective efferent VNS). The experiment was started 72 h postoperatively to allow for post-surgical recovery. Inflammation was induced with LPS bolus intravenously (LPS group, 400 ng/fetus/day for 2 days; n = 23). For the Vx + LPS group (n = 11), a bilateral cervical vagotomy was performed during surgery; of these n = 5 received double the LPS dose, LPS800. The Vx + LPS + efferent VNS group (n = 8) received cervical VNS probes bilaterally distal from Vx in eight animals. Efferent VNS was administered for 20 min on days 1 and 2 +/10 min around the LPS bolus. Fetal arterial blood samples were drawn on each postoperative day of recovery (-72 h, -48 h, and -24 h) as well as at the baseline and seven selected time points (3-54 h) to profile inflammation (ELISA IL-6, pg/mL), insulin (ELISA), blood gas, and metabolism (glucose). At 54 h post-LPS, a necropsy was performed, and the terminal ileum macrophages' CD11c (M1 phenotype) immunofluorescence was quantified to detect inflammation. The results are reported for p < 0.05 and for Spearman R2 > 0.1. The results are presented as the median (IQR). RESULTS Across the treatment groups, blood gas and cardiovascular changes indicated mild septicemia. At 3 h in the LPS group, IL-6 peaked. That peak was decreased in the Vx + LPS400 group and doubled in the Vx + LPS800 group. The efferent VNS sped up the reduction in the inflammatory response profile over 54 h. The M1 macrophage activity was increased in the LPS and Vx + LPS800 groups only. The glucose and insulin concentrations in the Vx + LPS group were, respectively, 1.3-fold (throughout the experiment) and 2.3-fold higher vs. control (at 3 h). The efferent VNS normalized the glucose concentrations. CONCLUSIONS The complete withdrawal of vagal innervation resulted in a 72-h delayed onset of a sustained increase in glucose for at least 54 h and intermittent hyperinsulinemia. Under the conditions of moderate fetal inflammation, this was related to higher levels of gut inflammation. The efferent VNS reduced the systemic inflammatory response as well as restored both the concentrations of glucose and the degree of terminal ileum inflammation, but not the insulin concentrations. Supporting our hypothesis, these findings revealed a novel regulatory, hormetic, role of the vagus nerve in the immunometabolic response to endotoxin in near-term fetuses.
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Affiliation(s)
- Mingju Cao
- Department of Obstetrics and Gynaecology and Department of Neurosciences, CHU Ste-Justine Research Centre, Université de Montréal, Montréal, QC H3T 1C5, Canada; (M.C.)
| | - Shikha Kuthiala
- Department of Obstetrics and Gynaecology and Department of Neurosciences, CHU Ste-Justine Research Centre, Université de Montréal, Montréal, QC H3T 1C5, Canada; (M.C.)
| | - Keven Jason Jean
- Department of Obstetrics and Gynaecology and Department of Neurosciences, CHU Ste-Justine Research Centre, Université de Montréal, Montréal, QC H3T 1C5, Canada; (M.C.)
| | - Hai Lun Liu
- Department of Obstetrics and Gynaecology and Department of Neurosciences, CHU Ste-Justine Research Centre, Université de Montréal, Montréal, QC H3T 1C5, Canada; (M.C.)
| | - Marc Courchesne
- Biotron Microscopy, Western University, London, ON N6A 3K7, Canada
| | - Karen Nygard
- Biotron Microscopy, Western University, London, ON N6A 3K7, Canada
| | - Patrick Burns
- Clinical Sciences, CHUV, Université de Montréal, St-Hyacinthe, QC J2S 2M2, Canada (A.D.)
| | - André Desrochers
- Clinical Sciences, CHUV, Université de Montréal, St-Hyacinthe, QC J2S 2M2, Canada (A.D.)
| | - Gilles Fecteau
- Clinical Sciences, CHUV, Université de Montréal, St-Hyacinthe, QC J2S 2M2, Canada (A.D.)
| | - Christophe Faure
- Department of Pediatrics, CHU Ste-Justine Research Centre, Université de Montréal, Montréal, QC H3T 1C5, Canada
| | - Martin G. Frasch
- Department of Obstetrics and Gynaecology and Department of Neurosciences, CHU Ste-Justine Research Centre, Université de Montréal, Montréal, QC H3T 1C5, Canada; (M.C.)
- Centre de Recherche en Reproduction Animale, l’Université de Montréal, St-Hyacinthe, QC H3T 1J4, Canada
- Department of Obstetrics and Gynecology and Institute on Human Development and Disability, School of Medicine, University of Washington, 1959 NE Pacific St Box 356460, Seattle, WA 98195, USA
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Nutma E, Fancy N, Weinert M, Tsartsalis S, Marzin MC, Muirhead RCJ, Falk I, Breur M, de Bruin J, Hollaus D, Pieterman R, Anink J, Story D, Chandran S, Tang J, Trolese MC, Saito T, Saido TC, Wiltshire KH, Beltran-Lobo P, Phillips A, Antel J, Healy L, Dorion MF, Galloway DA, Benoit RY, Amossé Q, Ceyzériat K, Badina AM, Kövari E, Bendotti C, Aronica E, Radulescu CI, Wong JH, Barron AM, Smith AM, Barnes SJ, Hampton DW, van der Valk P, Jacobson S, Howell OW, Baker D, Kipp M, Kaddatz H, Tournier BB, Millet P, Matthews PM, Moore CS, Amor S, Owen DR. Translocator protein is a marker of activated microglia in rodent models but not human neurodegenerative diseases. Nat Commun 2023; 14:5247. [PMID: 37640701 PMCID: PMC10462763 DOI: 10.1038/s41467-023-40937-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2023] [Accepted: 08/16/2023] [Indexed: 08/31/2023] Open
Abstract
Microglial activation plays central roles in neuroinflammatory and neurodegenerative diseases. Positron emission tomography (PET) targeting 18 kDa Translocator Protein (TSPO) is widely used for localising inflammation in vivo, but its quantitative interpretation remains uncertain. We show that TSPO expression increases in activated microglia in mouse brain disease models but does not change in a non-human primate disease model or in common neurodegenerative and neuroinflammatory human diseases. We describe genetic divergence in the TSPO gene promoter, consistent with the hypothesis that the increase in TSPO expression in activated myeloid cells depends on the transcription factor AP1 and is unique to a subset of rodent species within the Muroidea superfamily. Finally, we identify LCP2 and TFEC as potential markers of microglial activation in humans. These data emphasise that TSPO expression in human myeloid cells is related to different phenomena than in mice, and that TSPO-PET signals in humans reflect the density of inflammatory cells rather than activation state.
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Affiliation(s)
- Erik Nutma
- Department of Pathology, Amsterdam UMC - Location VUmc, Amsterdam, The Netherlands
- Department of Neurobiology and Aging, Biomedical Primate Research Centre, Rijswijk, The Netherlands
| | - Nurun Fancy
- Department of Brain Sciences, Imperial College London, London, UK
- UK Dementia Research Institute at Imperial College London, London, UK
| | - Maria Weinert
- Department of Brain Sciences, Imperial College London, London, UK
| | - Stergios Tsartsalis
- Department of Brain Sciences, Imperial College London, London, UK
- UK Dementia Research Institute at Imperial College London, London, UK
- Department of Psychiatry, University of Geneva, Geneva, Switzerland
| | - Manuel C Marzin
- Department of Pathology, Amsterdam UMC - Location VUmc, Amsterdam, The Netherlands
| | - Robert C J Muirhead
- Department of Brain Sciences, Imperial College London, London, UK
- UK Dementia Research Institute at Imperial College London, London, UK
| | - Irene Falk
- Viral Immunology Section, NIH, Bethesda, MD, USA
- Flow and Imaging Cytometry Core Facility, NIH, Bethesda, MD, USA
| | - Marjolein Breur
- Department of Pathology, Amsterdam UMC - Location VUmc, Amsterdam, The Netherlands
| | - Joy de Bruin
- Department of Pathology, Amsterdam UMC - Location VUmc, Amsterdam, The Netherlands
| | - David Hollaus
- Department of Pathology, Amsterdam UMC - Location VUmc, Amsterdam, The Netherlands
| | - Robin Pieterman
- Department of Pathology, Amsterdam UMC - Location VUmc, Amsterdam, The Netherlands
| | - Jasper Anink
- Department of (Neuro)Pathology, Amsterdam UMC, University of Amsterdam, Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - David Story
- UK Dementia Research Institute at Edinburgh, Edinburgh, UK
| | | | - Jiabin Tang
- Department of Brain Sciences, Imperial College London, London, UK
- UK Dementia Research Institute at Imperial College London, London, UK
| | - Maria C Trolese
- Department of Neuroscience, Mario Negri Institute for Pharmacological Research IRCCS, Milan, Italy
| | - Takashi Saito
- Laboratory for Proteolytic Neuroscience, RIKEN Brain Science Institute, Wako-shi, Saitama, Japan
| | - Takaomi C Saido
- Department of Neurocognitive Science, Institute of Brain Science, Nagoya City University, Nagoya, Japan
| | | | - Paula Beltran-Lobo
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Alexandra Phillips
- Department of Brain Sciences, Imperial College London, London, UK
- UK Dementia Research Institute at Imperial College London, London, UK
| | - Jack Antel
- Montreal Neurological Institute, McGill University, Montreal, Canada
| | - Luke Healy
- Montreal Neurological Institute, McGill University, Montreal, Canada
| | - Marie-France Dorion
- Division of Biomedical Sciences, Memorial University of Newfoundland, St. John's, Canada
| | - Dylan A Galloway
- Division of Biomedical Sciences, Memorial University of Newfoundland, St. John's, Canada
| | - Rochelle Y Benoit
- Division of Biomedical Sciences, Memorial University of Newfoundland, St. John's, Canada
| | - Quentin Amossé
- Department of Psychiatry, University of Geneva, Geneva, Switzerland
| | - Kelly Ceyzériat
- Department of Psychiatry, University of Geneva, Geneva, Switzerland
| | | | - Enikö Kövari
- Department of Psychiatry, University of Geneva, Geneva, Switzerland
| | - Caterina Bendotti
- Department of Neuroscience, Mario Negri Institute for Pharmacological Research IRCCS, Milan, Italy
| | - Eleonora Aronica
- Department of (Neuro)Pathology, Amsterdam UMC, University of Amsterdam, Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Carola I Radulescu
- Department of Brain Sciences, Imperial College London, London, UK
- UK Dementia Research Institute at Imperial College London, London, UK
| | - Jia Hui Wong
- Neurobiology of Aging and Disease Laboratory, Lee Kong Chian School of Medicine, Nanyang Technological University Singapore, Singapore, Singapore
| | - Anna M Barron
- Neurobiology of Aging and Disease Laboratory, Lee Kong Chian School of Medicine, Nanyang Technological University Singapore, Singapore, Singapore
| | - Amy M Smith
- UK Dementia Research Institute at Imperial College London, London, UK
- Centre for Brain Research and Department of Pharmacology and Clinical Pharmacology, University of Auckland, Auckland, New Zealand
| | - Samuel J Barnes
- Department of Brain Sciences, Imperial College London, London, UK
- UK Dementia Research Institute at Imperial College London, London, UK
| | | | - Paul van der Valk
- Department of Pathology, Amsterdam UMC - Location VUmc, Amsterdam, The Netherlands
| | | | - Owain W Howell
- Institute of Life Science (ILS), Swansea University Medical School, Swansea, UK
| | - David Baker
- Department of Neuroscience and Trauma, Blizard Institute, Queen Mary University of London, London, UK
| | - Markus Kipp
- Institute of Anatomy, Rostock University Medical Center, 18057, Rostock, Germany
| | - Hannes Kaddatz
- Institute of Anatomy, Rostock University Medical Center, 18057, Rostock, Germany
| | | | - Philippe Millet
- Department of Psychiatry, University of Geneva, Geneva, Switzerland
- Division of Adult Psychiatry, University Hospitals of Geneva, Geneva, Switzerland
| | - Paul M Matthews
- Department of Brain Sciences, Imperial College London, London, UK
- UK Dementia Research Institute at Imperial College London, London, UK
| | - Craig S Moore
- Division of Biomedical Sciences, Memorial University of Newfoundland, St. John's, Canada
| | - Sandra Amor
- Department of Pathology, Amsterdam UMC - Location VUmc, Amsterdam, The Netherlands.
- Department of Neuroscience and Trauma, Blizard Institute, Queen Mary University of London, London, UK.
- Institute of Anatomy, Rostock University Medical Center, 18057, Rostock, Germany.
| | - David R Owen
- Department of Brain Sciences, Imperial College London, London, UK.
- UK Dementia Research Institute at Imperial College London, London, UK.
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Oliveira AC, Karas MM, Alves M, He J, de Kloet AD, Krause EG, Richards EM, Bryant AJ, Raizada MK. ACE2 overexpression in corticotropin-releasing-hormone cells offers protection against pulmonary hypertension. Front Neurosci 2023; 17:1223733. [PMID: 37638323 PMCID: PMC10447887 DOI: 10.3389/fnins.2023.1223733] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Accepted: 07/21/2023] [Indexed: 08/29/2023] Open
Abstract
Background Pulmonary hypertension (PH), characterized by elevated pulmonary pressure and right heart failure, is a systemic disease involving inappropriate sympathetic activation and an impaired gut-brain-lung axis. Global overexpression of angiotensin converting enzyme 2 (ACE2), a cardiopulmonary protective enzyme of the renin-angiotensin system, attenuates PH induced by chronic hypoxia. Neurons within the paraventricular nucleus of the hypothalamus (PVN) that synthesize corticotropin-releasing hormone (CRH) are activated by stressors, like hypoxia, and this activation augments sympathetic outflow to cardiovascular tissues. These data coupled with our observations that ACE2 overexpression in CRH cells (CRH-ACE2KI mice) decreases anxiety-like behavior via suppression of hypothalamic-pituitary-adrenal (HPA) axis activity by decreasing CRH synthesis, led us to hypothesize that selective ACE2 overexpression in CRH neurons would protect against hypoxia-induced PH. Methods CRH-ACE2KI and WT male and female mice were exposed to chronic hypoxia (10%O2) or normoxia (21%O2) for 4 weeks in a ventilated chamber with continuous monitoring of oxygen and carbon dioxide concentrations (n = 7-10/group). Pulmonary hemodynamics were measured with Millar pressure catheters then tissues were collected for histological analyses. Results Chronic hypoxia induced a significant increase (36.4%) in right ventricular (RV) systolic pressure (RVSP) in WT mice, which was not observed in CRH-ACE2KI mice. No significant differences in RVSP were observed between male and female mice in any of the groups. Conclusion Overexpression of ACE2 in CRH cells was protective against hypoxia-induced PH. Since the majority of expression of CRH is in brain nuclei such as paraventricular nucleus of the hypothalamus (PVN) and/or central nucleus of the amygdala (CeA) these data indicate that the protective effects of ACE2 are, at least in part, centrally mediated. This contributes to the systemic nature of PH disease and that CRH neurons may play an important role in PH.
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Affiliation(s)
- Aline C. Oliveira
- Division of Pulmonary, Critical Care and Sleep Medicine, College of Medicine, University of Florida, Gainesville, FL, United States
| | - Marianthi M. Karas
- Division of Pulmonary, Critical Care and Sleep Medicine, College of Medicine, University of Florida, Gainesville, FL, United States
| | - Matthew Alves
- Division of Pulmonary, Critical Care and Sleep Medicine, College of Medicine, University of Florida, Gainesville, FL, United States
| | - Jacky He
- Evelyn F. and William L. McKnight Brain Institute, University of Florida, Gainesville, FL, United States
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, FL, United States
| | - Annette D. de Kloet
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, FL, United States
- Department of Physiology and Aging, College of Medicine, University of Florida, Gainesville, FL, United States
| | - Eric G. Krause
- Evelyn F. and William L. McKnight Brain Institute, University of Florida, Gainesville, FL, United States
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, FL, United States
- Center for Integrative Cardiovascular and Metabolic Diseases, University of Florida, Gainesville, FL, United States
| | - Elaine M. Richards
- Department of Physiology and Aging, College of Medicine, University of Florida, Gainesville, FL, United States
| | - Andrew J. Bryant
- Division of Pulmonary, Critical Care and Sleep Medicine, College of Medicine, University of Florida, Gainesville, FL, United States
| | - Mohan K. Raizada
- Department of Physiology and Aging, College of Medicine, University of Florida, Gainesville, FL, United States
- Center for Integrative Cardiovascular and Metabolic Diseases, University of Florida, Gainesville, FL, United States
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4
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Frasch MG, Yoon BJ, Helbing DL, Snir G, Antonelli MC, Bauer R. Autism Spectrum Disorder: A Neuro-Immunometabolic Hypothesis of the Developmental Origins. BIOLOGY 2023; 12:914. [PMID: 37508346 PMCID: PMC10375982 DOI: 10.3390/biology12070914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 06/15/2023] [Accepted: 06/21/2023] [Indexed: 07/30/2023]
Abstract
Fetal neuroinflammation and prenatal stress (PS) may contribute to lifelong neurological disabilities. Astrocytes and microglia, among the brain's non-neuronal "glia" cell populations, play a pivotal role in neurodevelopment and predisposition to and initiation of disease throughout lifespan. One of the most common neurodevelopmental disorders manifesting between 1-4 years of age is the autism spectrum disorder (ASD). A pathological glial-neuronal interplay is thought to increase the risk for clinical manifestation of ASD in at-risk children, but the mechanisms remain poorly understood, and integrative, multi-scale models are needed. We propose a model that integrates the data across the scales of physiological organization, from genome to phenotype, and provides a foundation to explain the disparate findings on the genomic level. We hypothesize that via gene-environment interactions, fetal neuroinflammation and PS may reprogram glial immunometabolic phenotypes that impact neurodevelopment and neurobehavior. Drawing on genomic data from the recently published series of ovine and rodent glial transcriptome analyses with fetuses exposed to neuroinflammation or PS, we conducted an analysis on the Simons Foundation Autism Research Initiative (SFARI) Gene database. We confirmed 21 gene hits. Using unsupervised statistical network analysis, we then identified six clusters of probable protein-protein interactions mapping onto the immunometabolic and stress response networks and epigenetic memory. These findings support our hypothesis. We discuss the implications for ASD etiology, early detection, and novel therapeutic approaches. We conclude with delineation of the next steps to verify our model on the individual gene level in an assumption-free manner. The proposed model is of interest for the multidisciplinary community of stakeholders engaged in ASD research, the development of novel pharmacological and non-pharmacological treatments, early prevention, and detection as well as for policy makers.
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Affiliation(s)
- Martin G Frasch
- Department of Obstetrics and Gynecology, University of Washington, Seattle, WA 98195, USA
- Center on Human Development and Disability, University of Washington, Seattle, WA 98195, USA
| | - Byung-Jun Yoon
- Electrical and Computer Engineering, Texas A&M University, College Station, TX 77843, USA
| | - Dario Lucas Helbing
- Institute for Molecular Cell Biology, Jena University Hospital, Friedrich Schiller University, 07747 Jena, Germany
- Leibniz Institute on Aging, Fritz Lipmann Institute, 07745 Jena, Germany
- Department of Psychiatry and Psychotherapy, Jena University Hospital, Friedrich Schiller University Jena, 07747 Jena, Germany
- Center for Intervention and Research on Adaptive and Maladaptive Brain Circuits Underlying Mental Health (C-I-R-C), Jena-Magdeburg-Halle, 07743 Jena, Germany
| | - Gal Snir
- Department of Obstetrics and Gynecology, University of Washington, Seattle, WA 98195, USA
| | - Marta C Antonelli
- Instituto de Biología Celular y Neurociencia "Prof. Eduardo De Robertis", Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires 1121, Argentina
- Institute for Advanced Study, Technical University of Munich, Lichtenbergstrasse 2 a, 85748 Garching, Germany
| | - Reinhard Bauer
- Institute for Molecular Cell Biology, Jena University Hospital, Friedrich Schiller University, 07747 Jena, Germany
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Lewis EL, Tulina N, Anton L, Brown AG, Porrett PM, Elovitz MA. IFNγ-Producing γ/δ T Cells Accumulate in the Fetal Brain Following Intrauterine Inflammation. Front Immunol 2021; 12:741518. [PMID: 34675929 PMCID: PMC8524441 DOI: 10.3389/fimmu.2021.741518] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 09/01/2021] [Indexed: 11/26/2022] Open
Abstract
Intrauterine inflammation impacts prenatal neurodevelopment and is linked to adverse neurobehavioral outcomes ranging from cerebral palsy to autism spectrum disorder. However, the mechanism by which a prenatal exposure to intrauterine inflammation contributes to life-long neurobehavioral consequences is unknown. To address this gap in knowledge, this study investigates how inflammation transverses across multiple anatomic compartments from the maternal reproductive tract to the fetal brain and what specific cell types in the fetal brain may cause long-term neuronal injury. Utilizing a well-established mouse model, we found that mid-gestation intrauterine inflammation resulted in a lasting neutrophil influx to the decidua in the absence of maternal systemic inflammation. Fetal immunologic changes were observed at 72-hours post-intrauterine inflammation, including elevated neutrophils and macrophages in the fetal liver, and increased granulocytes and activated microglia in the fetal brain. Through unbiased clustering, a population of Gr-1+ γ/δ T cells was identified as the earliest immune cell shift in the fetal brain of fetuses exposed to intrauterine inflammation and determined to be producing high levels of IFNγ when compared to γ/δ T cells in other compartments. In a case-control study of term infants, IFNγ was found to be elevated in the cord blood of term infants exposed to intrauterine inflammation compared to those without this exposure. Collectively, these data identify a novel cellular immune mechanism for fetal brain injury in the setting of intrauterine inflammation.
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Affiliation(s)
- Emma L Lewis
- Center for Research on Reproduction and Women's Health, University of Pennsylvania, Philadelphia, PA, United States
| | - Natalia Tulina
- Center for Research on Reproduction and Women's Health, University of Pennsylvania, Philadelphia, PA, United States
| | - Lauren Anton
- Center for Research on Reproduction and Women's Health, University of Pennsylvania, Philadelphia, PA, United States
| | - Amy G Brown
- Center for Research on Reproduction and Women's Health, University of Pennsylvania, Philadelphia, PA, United States
| | - Paige M Porrett
- Department of Surgery, Perelman School of Medicine, University of Pennsylvania, PA, United States
| | - Michal A Elovitz
- Center for Research on Reproduction and Women's Health, University of Pennsylvania, Philadelphia, PA, United States.,Department of Obstetrics and Gynecology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
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Couch ACM, Berger T, Hanger B, Matuleviciute R, Srivastava DP, Thuret S, Vernon AC. Maternal immune activation primes deficiencies in adult hippocampal neurogenesis. Brain Behav Immun 2021; 97:410-422. [PMID: 34352366 PMCID: PMC8478664 DOI: 10.1016/j.bbi.2021.07.021] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 06/25/2021] [Accepted: 07/28/2021] [Indexed: 12/19/2022] Open
Abstract
Neurogenesis, the process in which new neurons are generated, occurs throughout life in the mammalian hippocampus. Decreased adult hippocampal neurogenesis (AHN) is a common feature across psychiatric disorders, including schizophrenia, depression- and anxiety-related behaviours, and is highly regulated by environmental influences. Epidemiological studies have consistently implicated maternal immune activation (MIA) during neurodevelopment as a risk factor for psychiatric disorders in adulthood. The extent to which the reduction of hippocampal neurogenesis in adulthood may be driven by early life exposures, such as MIA, is however unclear. We therefore reviewed the literature for evidence of the involvement of MIA in disrupting AHN. Consistent with our hypothesis, data from both in vivo murine and in vitro human models of AHN provide evidence for key roles of specific cytokines induced by MIA in the foetal brain in disrupting hippocampal neural progenitor cell proliferation and differentiation early in development. The precise molecular mechanisms however remain unclear. Nonetheless, these data suggest a potential latent vulnerability mechanism, whereby MIA primes dysfunction in the unique hippocampal pool of neural stem/progenitor cells. This renders offspring potentially more susceptible to additional environmental exposures later in life, such as chronic stress, resulting in the unmasking of psychopathology. We highlight the need for studies to test this hypothesis using validated animal models of MIA, but also to test the relevance of such data for human pathology at a molecular basis through the use of patient-derived induced pluripotent stem cells (hiPSC) differentiated into hippocampal progenitor cells.
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Affiliation(s)
- Amalie C M Couch
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK; MRC Centre for Neurodevelopmental Disorders, King's College London, London, UK
| | - Thomas Berger
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Bjørn Hanger
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK; MRC Centre for Neurodevelopmental Disorders, King's College London, London, UK
| | | | - Deepak P Srivastava
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK; MRC Centre for Neurodevelopmental Disorders, King's College London, London, UK
| | - Sandrine Thuret
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Anthony C Vernon
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK; MRC Centre for Neurodevelopmental Disorders, King's College London, London, UK.
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7
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Recording and manipulation of vagus nerve electrical activity in chronically instrumented unanesthetized near term fetal sheep. J Neurosci Methods 2021; 360:109257. [PMID: 34139266 DOI: 10.1016/j.jneumeth.2021.109257] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Revised: 06/04/2021] [Accepted: 06/09/2021] [Indexed: 12/31/2022]
Abstract
BACKGROUND The chronically instrumented pregnant sheep has been used as a model of human fetal development and responses to pathophysiologic stimuli. This is due to the unique amenability of the unanesthetized fetal sheep to the surgical placement and maintenance of catheters and electrodes, allowing repetitive blood sampling, substance injection, recording of bioelectrical activity, application of electric stimulation, and in vivo organ imaging. Recently, there has been growing interest in the pleiotropic effects of vagus nerve stimulation (VNS) on various organ systems such as innate immunity and inflammation, and metabolism. There is no approach to study this in utero and corresponding physiological understanding is scarce. NEW METHOD Based on our previous presentation of a stable chronically instrumented unanesthetized fetal sheep model, here we describe the surgical instrumentation procedure allowing successful implantation of a cervical uni- or bilateral VNS probe with or without vagotomy. RESULTS In a cohort of 68 animals, we present the changes in blood gas, metabolic, and inflammatory markers during the postoperative period. We detail the design of a VNS probe which also allows recording from the fetal nerve. We also present an example of fetal vagus electroneurogram (VENG) recorded from the VNS probe and an analytical approach to the data. COMPARISON WITH EXISTING METHODS This method represents the first implementation of fetal VENG/VNS in a large pregnant mammalian organism. CONCLUSIONS This study describes a new surgical procedure allowing to record and manipulate chronically fetal vagus nerve activity in an animal model of human pregnancy.
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Epigenetic Modulation of Microglia Function and Phenotypes in Neurodegenerative Diseases. Neural Plast 2021; 2021:9912686. [PMID: 34194489 PMCID: PMC8181095 DOI: 10.1155/2021/9912686] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 05/14/2021] [Indexed: 12/14/2022] Open
Abstract
Microglia-mediated neuroinflammation is one of the most remarkable hallmarks of neurodegenerative diseases (NDDs), including AD, PD, and ALS. Accumulating evidence indicates that microglia play both neuroprotective and detrimental roles in the onset and progression of NDDs. Yet, the specific mechanisms of action surrounding microglia are not clear. Modulation of microglia function and phenotypes appears to be a potential strategy to reverse NDDs. Until recently, research into the epigenetic mechanisms of diseases has been gradually developed, making it possible to elucidate the molecular mechanisms underlying the epigenetic regulation of microglia in NDDs. This review highlights the function and phenotypes of microglia, elucidates the relationship between microglia, epigenetic modifications, and NDDs, as well as the possible mechanisms underlying the epigenetic modulation of microglia in NDDs with a focus on potential intervention strategies.
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9
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Han J, Fan Y, Zhou K, Blomgren K, Harris RA. Uncovering sex differences of rodent microglia. J Neuroinflammation 2021; 18:74. [PMID: 33731174 PMCID: PMC7972194 DOI: 10.1186/s12974-021-02124-z] [Citation(s) in RCA: 72] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 03/05/2021] [Indexed: 12/11/2022] Open
Abstract
There are inherent structural and functional differences in the central nervous systems (CNS) of females and males. It has been gradually established that these sex-specific differences are due to a spectrum of genetic, epigenetic, and hormonal factors which actively contribute to the differential incidences, disease courses, and even outcomes of CNS diseases between sexes. Microglia, as principle resident macrophages in the CNS, play a crucial role in both CNS physiology and pathology. However, sex differences of microglia have been relatively unexplored until recently. Emerging data has convincingly demonstrated the existence of sex-dependent structural and functional differences of rodent microglia, consequently changing our current understanding of these versatile cells. In this review, we attempt to comprehensively outline the current advances revealing microglial sex differences in rodent and their potential implications for specific CNS diseases with a stark sex difference. A detailed understanding of molecular processes underlying microglial sex differences is of major importance in design of translational sex- and microglia-specific therapeutic approaches.
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Affiliation(s)
- Jinming Han
- Applied Immunology and Immunotherapy, Department of Clinical Neuroscience, Karolinska Institutet, Center for Molecular Medicine, Karolinska University Hospital, CMM L8:04, Karolinska Sjukhuset, S-171 76, Stockholm, Sweden.
| | - Yueshan Fan
- Applied Immunology and Immunotherapy, Department of Clinical Neuroscience, Karolinska Institutet, Center for Molecular Medicine, Karolinska University Hospital, CMM L8:04, Karolinska Sjukhuset, S-171 76, Stockholm, Sweden.,Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin, China.,Key Laboratory of Injuries, Variations and Regeneration of Nervous System, Tianjin Neurological Institute, Tianjin, China.,Tianjin Medical University, Tianjin, China
| | - Kai Zhou
- Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden.,Department of Pediatrics, Children's Hospital of Zhengzhou, Zhengzhou, China
| | - Klas Blomgren
- Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden.,Pediatric Oncology, Karolinska University Hospital, Stockholm, Sweden
| | - Robert A Harris
- Applied Immunology and Immunotherapy, Department of Clinical Neuroscience, Karolinska Institutet, Center for Molecular Medicine, Karolinska University Hospital, CMM L8:04, Karolinska Sjukhuset, S-171 76, Stockholm, Sweden.
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10
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The Role of the Pathogen Dose and PI3Kγ in Immunometabolic Reprogramming of Microglia for Innate Immune Memory. Int J Mol Sci 2021; 22:ijms22052578. [PMID: 33806610 PMCID: PMC7961448 DOI: 10.3390/ijms22052578] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 01/23/2021] [Accepted: 02/26/2021] [Indexed: 12/16/2022] Open
Abstract
Microglia, the innate immune cells of the CNS, exhibit long-term response changes indicative of innate immune memory (IIM). Our previous studies revealed IIM patterns of microglia with opposing immune phenotypes: trained immunity after a low dose and immune tolerance after a high dose challenge with pathogen-associated molecular patterns (PAMP). Compelling evidence shows that innate immune cells adopt features of IIM via immunometabolic control. However, immunometabolic reprogramming involved in the regulation of IIM in microglia has not been fully addressed. Here, we evaluated the impact of dose-dependent microglial priming with ultra-low (ULP, 1 fg/mL) and high (HP, 100 ng/mL) lipopolysaccharide (LPS) doses on immunometabolic rewiring. Furthermore, we addressed the role of PI3Kγ on immunometabolic control using naïve primary microglia derived from newborn wild-type mice, PI3Kγ-deficient mice and mice carrying a targeted mutation causing loss of lipid kinase activity. We found that ULP-induced IIM triggered an enhancement of oxygen consumption and ATP production. In contrast, HP was followed by suppressed oxygen consumption and glycolytic activity indicative of immune tolerance. PI3Kγ inhibited glycolysis due to modulation of cAMP-dependent pathways. However, no impact of specific PI3Kγ signaling on immunometabolic rewiring due to dose-dependent LPS priming was detected. In conclusion, immunometabolic reprogramming of microglia is involved in IIM in a dose-dependent manner via the glycolytic pathway, oxygen consumption and ATP production: ULP (ultra-low-dose priming) increases it, while HP reduces it.
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11
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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] [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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12
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Timmerman R, Burm SM, Bajramovic JJ. Tissue-specific features of microglial innate immune responses. Neurochem Int 2020; 142:104924. [PMID: 33248205 DOI: 10.1016/j.neuint.2020.104924] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 11/21/2020] [Accepted: 11/22/2020] [Indexed: 02/07/2023]
Abstract
As tissue-resident macrophages of the brain, microglia are increasingly considered as cellular targets for therapeutical intervention. Innate immune responses in particular have been implicated in central nervous system (CNS) infections, neuro-oncology, neuroinflammatory and neurodegenerative diseases. We here review the impact of 'nature and nurture' on microglial innate immune responses and summarize documented tissue-specific adaptations. Overall, such adaptations are associated with regulatory processes rather than with overt differences in the expressed repertoire of activating receptors of different tissue-resident macrophages. Microglial responses are characterized by slower kinetics, by a more persistent nature and by a differential usage of downstream enzymes and accessory receptors. We further consider factors like aging, previous exposure to inflammatory stimuli, and differences in the microenvironment that can modulate innate immune responses. The long-life span of microglia in the metabolically active CNS renders them susceptible to the phenomenon of 'inflammaging', and major challenges lie in the unraveling of the factors that underlie age-related alterations in microglial behavior.
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Affiliation(s)
- R Timmerman
- Alternatives Unit, Biomedical Primate Research Centre, Rijswijk, the Netherlands
| | - S M Burm
- Genmab, Utrecht, the Netherlands
| | - J J Bajramovic
- Alternatives Unit, Biomedical Primate Research Centre, Rijswijk, the Netherlands.
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13
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Gamage R, Wagnon I, Rossetti I, Childs R, Niedermayer G, Chesworth R, Gyengesi E. Cholinergic Modulation of Glial Function During Aging and Chronic Neuroinflammation. Front Cell Neurosci 2020; 14:577912. [PMID: 33192323 PMCID: PMC7594524 DOI: 10.3389/fncel.2020.577912] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 09/07/2020] [Indexed: 12/12/2022] Open
Abstract
Aging is a complex biological process that increases the risk of age-related cognitive degenerative diseases such as dementia, including Alzheimer’s disease (AD), Lewy Body Dementia (LBD), and mild cognitive impairment (MCI). Even non-pathological aging of the brain can involve chronic oxidative and inflammatory stress, which disrupts the communication and balance between the brain and the immune system. There has been an increasingly strong connection found between chronic neuroinflammation and impaired memory, especially in AD. While microglia and astrocytes, the resident immune cells of the central nervous system (CNS), exerting beneficial effects during the acute inflammatory phase, during chronic neuroinflammation they can become more detrimental. Central cholinergic circuits are involved in maintaining normal cognitive function and regulating signaling within the entire cerebral cortex. While neuronal-glial cholinergic signaling is anti-inflammatory and anti-oxidative, central cholinergic neuronal degeneration is implicated in impaired learning, memory sleep regulation, and attention. Although there is evidence of cholinergic involvement in memory, fewer studies have linked the cholinergic anti-inflammatory and anti-oxidant pathways to memory processes during development, normal aging, and disease states. This review will summarize the current knowledge of cholinergic effects on microglia and astroglia, and their role in both anti-inflammatory and anti-oxidant mechanisms, concerning normal aging and chronic neuroinflammation. We provided details on how stimulation of α7 nicotinic acetylcholine (α7nACh) receptors can be neuroprotective by increasing amyloid-β phagocytosis, decreasing inflammation and reducing oxidative stress by promoting the nuclear factor erythroid 2-related factor 2 (Nrf2) pathways and decreasing the release of pro-inflammatory cytokines. There is also evidence for astroglial α7nACh receptor stimulation mediating anti-inflammatory and antioxidant effects by inhibiting the nuclear factor-κB (NF-κB) pathway and activating the Nrf2 pathway respectively. We conclude that targeting cholinergic glial interactions between neurons and glial cells via α7nACh receptors could regulate neuroinflammation and oxidative stress, relevant to the treatment of several neurodegenerative diseases.
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Affiliation(s)
- Rashmi Gamage
- Department of Pharmacology, School of Medicine, Western Sydney University, Penrith, NSW, Australia
| | - Ingrid Wagnon
- Department of Pharmacology, School of Medicine, Western Sydney University, Penrith, NSW, Australia
| | - Ilaria Rossetti
- Department of Pharmacology, School of Medicine, Western Sydney University, Penrith, NSW, Australia
| | - Ryan Childs
- Department of Pharmacology, School of Medicine, Western Sydney University, Penrith, NSW, Australia
| | - Garry Niedermayer
- School of Science, Western Sydney University, Penrith, NSW, Australia
| | - Rose Chesworth
- School of Medicine, Western Sydney University, Penrith, NSW, Australia
| | - Erika Gyengesi
- Department of Pharmacology, School of Medicine, Western Sydney University, Penrith, NSW, Australia
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14
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Desplats P, Gutierrez AM, Antonelli MC, Frasch MG. Microglial memory of early life stress and inflammation: Susceptibility to neurodegeneration in adulthood. Neurosci Biobehav Rev 2020; 117:232-242. [PMID: 31703966 PMCID: PMC7198341 DOI: 10.1016/j.neubiorev.2019.10.013] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2018] [Revised: 09/15/2019] [Accepted: 10/20/2019] [Indexed: 02/08/2023]
Abstract
We review evidence supporting the role of early life programming in the susceptibility for adult neurodegenerative diseases while highlighting questions and proposing avenues for future research to advance our understanding of this fundamental process. The key elements of this phenomenon are chronic stress, neuroinflammation triggering microglial polarization, microglial memory and their connection to neurodegeneration. We review the mediating mechanisms which may function as early biomarkers of increased susceptibility for neurodegeneration. Can we devise novel early life modifying interventions to steer developmental trajectories to their optimum?
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Affiliation(s)
- Paula Desplats
- Department of Neurosciences, University of California San Diego, CA, USA; Department of Pathology, University of California San Diego, CA, USA
| | - Ashley M Gutierrez
- Department of Neurosciences, University of California San Diego, CA, USA
| | - Marta C Antonelli
- Instituto de Biología Celular y Neurociencia "Prof. Eduardo De Robertis", Facultad de Medicina, Universidad de Buenos Aires, Argentina; Department of Obstetrics and Gynecology, Klinikum rechts der Isar, Technical University of Munich, Germany
| | - Martin G Frasch
- Department of Obstetrics and Gynecology, University of Washington, Seattle, WA, USA; Center on Human Development and Disability, University of Washington, Seattle, WA, USA.
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15
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Evans MI, Britt DW, Eden RD, Evans SM, Schifrin BS. Earlier and improved screening for impending fetal compromise. J Matern Fetal Neonatal Med 2020; 35:2895-2903. [PMID: 32873102 DOI: 10.1080/14767058.2020.1811670] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVE The use of pH and base excess (FSSPHBE) from fetal scalp sampling (FSS) was abandoned when cardiotocography (CTG) was believed to be sufficiently accurate to direct patient management. We sought to understand the fetus' tolerance to stress in the 1st stage of labor and to develop a better and earlier screening test for its risk for developing acidosis. To do so, we investigated sequential changes in fetal pH and BE obtained from FSS in the 1st stage of labor as part of a research protocol from the 1970s. We then examined the utility of multiple of the median (MoM's) conversion of BE and pH values, and the capacity of Fetal Reserve Index (FRI) scores to be a proxy for such changes. We then sought to examine the predictive capacity of 1st stage FRI and its change over the course of the first stage of labor for the subsequent development of acidosis risk in the 2nd stage of labor. METHODS Using a retrospective research database evaluation, we evaluated FSSPHBE data from 475 high-risk parturients monitored in labor and their neonates for 1 h postpartum. We categorized specimens according to cervical dilatation (CxD) at the time of FSSPHBE and developed non-parametric, multiples of the median (MOMs) assessments. FRI scores and their change over time were used as predictors of FSSPHBE. Our main outcome measures were the changes in BE and pH at different cervical dilatations (CxD) and acidosis risk in the early 2nd stage of labor. RESULTS FSSPHBE worsens over the course of the 1st stage. The implications of any given BE are very different depending upon CxD. At 9 cm, -8 Mmol/L is 1.1 MOM; at 3 cm, it would be 2.0 MOM. The FRI level and its trajectory provide a 1st stage screening tool for acidosis risk in the second stage. CONCLUSIONS Fetal acid-base balance ("reserve") deteriorates beginning early in the 1st stage of labor, irrespective of whether the fetus reaches a critical threshold of concern for actual acidosis. The use of MoM's logic improves appreciation of such information. The FRI and its trajectory reasonably approximate the trajectory of the FSSPHBE and appears to be a suitable screening test for early deterioration and for earlier interventions to keep the fetus out of trouble rather than wait until high risk status develops.
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Affiliation(s)
- Mark I Evans
- Comprehensive Genetics, Fetal Medicine Foundation of America, New York, NY, USA.,Departments of Obstetrics and Gynecology, Icahn School of Medicine at Mt. Sinai, New York, NY, USA
| | - David W Britt
- Comprehensive Genetics, Fetal Medicine Foundation of America, New York, NY, USA
| | - Robert D Eden
- Comprehensive Genetics, Fetal Medicine Foundation of America, New York, NY, USA.,SUNY Syracuse, New York, NY, USA
| | - Shara M Evans
- Comprehensive Genetics, Fetal Medicine Foundation of America, New York, NY, USA.,Departement of Maternal Child Health, Gillings School of Public Health, University of North Carolina at Chapel Hill Chapel Hill, NC, USA
| | - Barry S Schifrin
- Comprehensive Genetics, Fetal Medicine Foundation of America, New York, NY, USA
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16
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Oliveira AC, Richards EM, Raizada MK. Pulmonary hypertension: Pathophysiology beyond the lung. Pharmacol Res 2020; 151:104518. [PMID: 31730803 PMCID: PMC6981289 DOI: 10.1016/j.phrs.2019.104518] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 10/25/2019] [Accepted: 10/29/2019] [Indexed: 12/11/2022]
Abstract
Pulmonary hypertension (PH) is classically considered a disease of pulmonary vasculature which has been the predominant target for drug development and PH therapy. Despite significant advancement in recent years in identification of new drug targets and innovative treatment strategies, the prognosis of PH remains poor, with median survival of 5 years. Recent studies have demonstrated involvement of neuroinflammation, altered autonomic and gastrointestinal functions and increased trafficking of bone marrow-derived cells in cardiopulmonary pathophysiology. This has led to the proposal that PH could be considered a systemic disease involving complex interactions among many organs. Our objectives in this review is to summarize evidence for the involvement of the brain, bone marrow and gut in PH pathophysiology. Then, to synthesize all evidence supporting a brain-gut-lung interaction hypothesis for consideration in PH pathophysiology and finally to summarize unanswered questions and future directions to move this novel concept forward. This forward-thinking view, if proven by further experiments, would provide new opportunities and novel targets for the control and treatment of PH.
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Affiliation(s)
- Aline C Oliveira
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - Elaine M Richards
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - Mohan K Raizada
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville, FL 32610, USA.
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17
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McNamara NB, Miron VE. Microglia in developing white matter and perinatal brain injury. Neurosci Lett 2019; 714:134539. [PMID: 31614181 DOI: 10.1016/j.neulet.2019.134539] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 10/04/2019] [Accepted: 10/07/2019] [Indexed: 12/13/2022]
Abstract
Perinatal brain injury (PBI) to the developing white matter results in hypomyelination of axons and can cause long-term motor and cognitive deficits e.g. cerebral palsy. There are currently no approved therapies aimed at repairing the white matter following insult, underscoring the need to investigate the mechanisms underlying the pathogenesis of PBI. Microglia have been strongly implicated, but their function and heterogeneity in this context remain poorly understood, posing a barrier to the development of microglia-targeted therapies for white matter repair following PBI. In this review, we discuss the roles of microglia in normal white matter development and in PBI, and potential drug strategies to influence microglial responses in this setting.
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Affiliation(s)
- Niamh B McNamara
- Medical Research Council Centre for Reproductive Health, The Queen's Medical Research Institute, The University of Edinburgh, Edinburgh, United Kingdom
| | - Veronique E Miron
- Medical Research Council Centre for Reproductive Health, The Queen's Medical Research Institute, The University of Edinburgh, Edinburgh, United Kingdom.
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18
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Cao M, MacDonald JW, Liu HL, Weaver M, Cortes M, Durosier LD, Burns P, Fecteau G, Desrochers A, Schulkin J, Antonelli MC, Bernier RA, Dorschner M, Bammler TK, Frasch MG. α7 Nicotinic Acetylcholine Receptor Signaling Modulates Ovine Fetal Brain Astrocytes Transcriptome in Response to Endotoxin. Front Immunol 2019; 10:1063. [PMID: 31143190 PMCID: PMC6520997 DOI: 10.3389/fimmu.2019.01063] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Accepted: 04/25/2019] [Indexed: 11/13/2022] Open
Abstract
Neuroinflammation in utero may result in lifelong neurological disabilities. Astrocytes play a pivotal role in this process, but the mechanisms are poorly understood. No early postnatal treatment strategies exist to enhance neuroprotective potential of astrocytes. We hypothesized that agonism on α7 nicotinic acetylcholine receptor (α7nAChR) in fetal astrocytes will augment their neuroprotective transcriptome profile, while the inhibition of α7nAChR will achieve the opposite. Using an in vivo–in vitro model of developmental programming of neuroinflammation induced by lipopolysaccharide (LPS), we validated this hypothesis in primary fetal sheep astrocytes cultures re-exposed to LPS in the presence of a selective α7nAChR agonist or antagonist. Our RNAseq findings show that a pro-inflammatory astrocyte transcriptome phenotype acquired in vitro by LPS stimulation is reversed with α7nAChR agonistic stimulation. Conversely, α7nAChR inhibition potentiates the pro-inflammatory astrocytic transcriptome phenotype. Furthermore, we conducted a secondary transcriptome analysis against the identical α7nAChR experiments in fetal sheep primary microglia cultures. Similar to findings in fetal microglia, in fetal astrocytes we observed a memory effect of in vivo exposure to inflammation, expressed in a perturbation of the iron homeostasis signaling pathway (hemoxygenase 1, HMOX1), which persisted under pre-treatment with α7nAChR antagonist but was reversed with α7nAChR agonist. For both glia cell types, common pathways activated due to LPS included neuroinflammation signaling and NF-κB signaling in some, but not all comparisons. However, overall, the overlap on the level of signaling pathways was rather minimal. Astrocytes, not microglia—the primary immune cells of the brain, were characterized by unique inhibition patterns of STAT3 pathway due to agonistic stimulation of α7nAChR prior to LPS exposure. Lastly, we discuss the implications of our findings for fetal and postnatal brain development.
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Affiliation(s)
- Mingju Cao
- Department of Obstetrics and Gynaecology and Department of Neurosciences, CHU Ste-Justine Research Centre, Faculty of Medicine, Université de Montréal, Montréal, QC, Canada
| | - James W MacDonald
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, United States
| | - Hai L Liu
- Department of Obstetrics and Gynaecology and Department of Neurosciences, CHU Ste-Justine Research Centre, Faculty of Medicine, Université de Montréal, Montréal, QC, Canada
| | - Molly Weaver
- UW Medicine Center for Precision Diagnostics, University of Washington, Seattle, WA, United States
| | - Marina Cortes
- Animal Reproduction Research Centre (CRRA), Faculty of Veterinary Medicine, Université de Montréal, Montréal, QC, Canada
| | - Lucien D Durosier
- Department of Obstetrics and Gynaecology and Department of Neurosciences, CHU Ste-Justine Research Centre, Faculty of Medicine, Université de Montréal, Montréal, QC, Canada
| | - Patrick Burns
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Université de Montréal, Montréal, QC, Canada
| | - Gilles Fecteau
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Université de Montréal, Montréal, QC, Canada
| | - André Desrochers
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Université de Montréal, Montréal, QC, Canada
| | - Jay Schulkin
- Department of Obstetrics and Gynecology, University of Washington, Seattle, WA, United States
| | - Marta C Antonelli
- Instituto de Biología Celular y Neurociencia "Prof. Eduardo De Robertis", Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Raphael A Bernier
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA, United States
| | - Michael Dorschner
- UW Medicine Center for Precision Diagnostics, University of Washington, Seattle, WA, United States
| | - Theo K Bammler
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, United States
| | - Martin G Frasch
- Department of Obstetrics and Gynaecology and Department of Neurosciences, CHU Ste-Justine Research Centre, Faculty of Medicine, Université de Montréal, Montréal, QC, Canada.,Animal Reproduction Research Centre (CRRA), Faculty of Veterinary Medicine, Université de Montréal, Montréal, QC, Canada.,Department of Obstetrics and Gynecology, University of Washington, Seattle, WA, United States.,Center on Human Development and Disability, University of Washington, Seattle, WA, United States
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19
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Gumusoglu SB, Stevens HE. Maternal Inflammation and Neurodevelopmental Programming: A Review of Preclinical Outcomes and Implications for Translational Psychiatry. Biol Psychiatry 2019; 85:107-121. [PMID: 30318336 DOI: 10.1016/j.biopsych.2018.08.008] [Citation(s) in RCA: 129] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 08/01/2018] [Accepted: 08/06/2018] [Indexed: 02/06/2023]
Abstract
Early disruptions to neurodevelopment are highly relevant to understanding both psychiatric risk and underlying pathophysiology that can be targeted by new treatments. Much convergent evidence from the human literature associates inflammation during pregnancy with later neuropsychiatric disorders in offspring. Preclinical models of prenatal inflammation have been developed to examine the causal maternal physiological and offspring neural mechanisms underlying these findings. Here we review the strengths and limitations of preclinical models used for these purposes and describe selected studies that have shown maternal immune impacts on the brain and behavior of offspring. Maternal immune activation in mice, rats, nonhuman primates, and other mammalian model species have demonstrated convergent outcomes across methodologies. These outcomes include shifts and/or disruptions in the normal developmental trajectory of molecular and cellular processes in the offspring brain. Prenatal developmental origins are critical to a mechanistic understanding of maternal immune activation-induced alterations to microglia and immune molecules, brain growth and development, synaptic morphology and physiology, and anxiety- and depression-like, sensorimotor, and social behaviors. These phenotypes are relevant to brain functioning across domains and to anxiety and mood disorders, schizophrenia, and autism spectrum disorder, in which they have been identified. By turning a neurodevelopmental lens on this body of work, we emphasize the importance of acute changes to the prenatal offspring brain in fostering a better understanding of potential mechanisms for intervention. Collectively, overlapping results across maternal immune activation studies also highlight the need to examine preclinical offspring neurodevelopment alterations in terms of a multifactorial immune milieu, or immunome, to determine potential mechanisms of psychiatric risk.
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Affiliation(s)
- Serena B Gumusoglu
- Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, Iowa
| | - Hanna E Stevens
- Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, Iowa; Department of Psychiatry, Carver College of Medicine, University of Iowa, Iowa City, Iowa; Iowa Neuroscience Institute, University of Iowa, Iowa City, Iowa.
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20
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Edlow AG, Glass RM, Smith CJ, Tran PK, James K, Bilbo S. Placental Macrophages: A Window Into Fetal Microglial Function in Maternal Obesity. Int J Dev Neurosci 2018; 77:60-68. [PMID: 30465871 DOI: 10.1016/j.ijdevneu.2018.11.004] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 11/05/2018] [Accepted: 11/14/2018] [Indexed: 01/18/2023] Open
Abstract
Fetal placental macrophages and microglia (resident brain macrophages) have a common origin in the fetal yolk sac. Yolk-sac-derived macrophages comprise the permanent pool of brain microglia throughout an individual's lifetime. Inappropriate fetal microglial priming may therefore have lifelong neurodevelopmental consequences, but direct evaluation of microglial function in a living fetus or neonate is impossible. We sought to test the hypothesis that maternal obesity would prime both placental macrophages and fetal brain microglia to overrespond to an immune challenge, thus providing a window into microglial function using placental cells. Obesity was induced in C57BL/6 J mice using a 60% high-fat diet. On embryonic day 17.5, fetal brain microglia and corresponding CD11b + placental cells were isolated from fresh tissue. Cells were treated with media or lipopolysaccharide (LPS). Tumor necrosis factor-alpha (TNF-α) production by stimulated and unstimulated cells was quantified via ELISA. We demonstrate for the first time that the proinflammatory cytokine production of CD11b + placental cells is strongly correlated with that of brain microglia (Spearman's ρ = 0.73, p = 0.002) in the setting of maternal obesity. Maternal obesity-exposed CD11b + cells had an exaggerated response to LPS compared to controls, with a 5.1-fold increase in TNF-α production in placentas (p = 0.003) and 3.8-fold increase in TNF-α production in brains (p = 0.002). In sex-stratified analyses, only male obesity-exposed brains and placentas had significant increase in TNF-α production in response to LPS. Taken together, these data suggest that maternal obesity primes both placental macrophages and fetal brain microglia to overproduce a proinflammatory cytokine in response to immune challenge. Male brain and placental immune response is more marked than female in this setting. Given that fetal microglial priming may impact neuroimmune function throughout the lifespan, these data could provide insight into the male predominance of certain neurodevelopmental morbidities linked to maternal obesity, including cognitive dysfunction, autism spectrum disorder, and ADHD. Placental CD11b+ macrophages may have the potential to serve as an accessible biomarker of aberrant fetal brain immune activation in maternal obesity. This finding may have broader implications for assaying the impact of other maternal exposures on fetal brain development.
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Affiliation(s)
- Andrea G Edlow
- Obstetrics, Gynecology, and Reproductive Biology, Harvard Medical School, Massachusetts General Hospital, Vincent Center for Reproductive Biology
| | - Ruthy M Glass
- Obstetrics, Gynecology, and Reproductive Biology, Harvard Medical School, Massachusetts General Hospital, Vincent Center for Reproductive Biology
| | - Caroline J Smith
- Pediatrics and Program in Neuroscience, Harvard Medical School, Lurie Center for Autism, MassGeneral Hospital for Children
| | - Phuong Kim Tran
- Pediatrics and Program in Neuroscience, Harvard Medical School, Lurie Center for Autism, MassGeneral Hospital for Children
| | - Kaitlyn James
- Massachusetts General Hospital, Deborah Kelly Center for Outcomes Research
| | - Staci Bilbo
- Pediatrics and Program in Neuroscience, Harvard Medical School, Lurie Center for Autism, MassGeneral Hospital for Children
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Cheray M, Joseph B. Epigenetics Control Microglia Plasticity. Front Cell Neurosci 2018; 12:243. [PMID: 30123114 PMCID: PMC6085560 DOI: 10.3389/fncel.2018.00243] [Citation(s) in RCA: 92] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 07/18/2018] [Indexed: 01/31/2023] Open
Abstract
Microglia, resident immune cells of the central nervous system, fulfill multiple functions in the brain throughout life. These microglial functions range from participation in innate and adaptive immune responses, involvement in the development of the brain and its homeostasis maintenance, to contribution to degenerative, traumatic, and proliferative diseases; and take place in the developing, the aging, the healthy, or the diseased brain. Thus, an impressive level of cellular plasticity, appears as a requirement for the pleiotropic biological functions of microglia. Epigenetic changes, including histone modifications or DNA methylation as well as microRNA expression, are important modifiers of gene expression, and have been involved in cell phenotype regulation and reprogramming and are therefore part of the mechanisms regulating cellular plasticity. Here, we review and discuss the epigenetic mechanisms, which are emerging as contributors to this microglial cellular plasticity and thereby can constitute interesting targets to modulate microglia associated brain diseases, including developmental diseases, neurodegenerative diseases as well as cancer.
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Affiliation(s)
- Mathilde Cheray
- Toxicology Unit, Institute of Environmental Medicine, Karolinska Institutet, Solna, Sweden
| | - Bertrand Joseph
- Toxicology Unit, Institute of Environmental Medicine, Karolinska Institutet, Solna, Sweden
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22
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Trained innate immunity: a salient factor in the pathogenesis of neuroimmune psychiatric disorders. Mol Psychiatry 2018; 23:170-176. [PMID: 29230022 DOI: 10.1038/mp.2017.186] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Revised: 07/07/2017] [Accepted: 07/13/2017] [Indexed: 02/07/2023]
Abstract
Historically, only cells of the adaptive immune system have been considered capable of retaining memory for infectious challenges. Recently, however, cells of the innate immune system have been shown to be capable of displaying long-term functional memory following a single immunostimulatory challenge, leading to enhanced production of proinflammatory molecules upon other subsequent, and temporally distant, immunostimulatory challenges. This effect has been termed 'trained innate immunity', and is underwritten by stable epigenetic changes in immune and metabolic pathways. Importantly, the long-term training of innate immune cells can occur as a result of infectious as well as and non-infectious challenges, including stress. Given the role that both stress and an activated immune system have in neuropathology, innate immune training has important implications for our understanding and treatment of neuropsychiatric disorders. This review focuses on the evidence for trained innate immunity and highlights some insights into its relevance for psychiatric diseases.
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Frasch MG, Burns P, Benito J, Cortes M, Cao M, Fecteau G, Desrochers A. Sculpting the Sculptors: Methods for Studying the Fetal Cholinergic Signaling on Systems and Cellular Scales. Methods Mol Biol 2018; 1781:341-352. [PMID: 29705856 DOI: 10.1007/978-1-4939-7828-1_18] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The non-neuronal, immunological effects of the cholinergic signaling are exerted on the system's scale of observation via the vagus nerve and on the cellular scale via α7 nicotinic acetylcholine receptor (nAChR) signaling in myeloid cells of the periphery or brain's microglia and astrocytes. The developmental effects of such multi-scale signaling can be conceived of as an example of psychoneuroimmunological (PNI) homeokinesis and, while reported in the literature, are not yet systematically well studied. To be better understood, the intricacy of the multi-scale interactions requires relevant preclinical animal models. Chronically instrumented non-anesthetized fetal sheep model comes with a strong track record of bench-to-bed translation and a large body of evidence for its strong resemblance to and relevance for human physiology on various scales of organization. Recently, there has been growing interest in pleiotropic effects of vagus nerve stimulation (VNS) on various organ systems such as innate immunity, metabolism, and emotion with implications for programming of PNI phenotype. Here we describe the procedures required to record and manipulate the vagus nerve activity in this large pregnant mammalian organism. Extending this in vivo model to in vitro, on the cellular scale, we present the method to manipulate the cholinergic signaling in ovine fetal microglia and astrocytes and analyze their responses on protein and RNA levels. Together these models can provide multi-scale-level mechanistic insights into the effects of cholinergic signaling on PNI phenotype.
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Affiliation(s)
- Martin G Frasch
- Department of Obstetrics and Gynaecology, University of Washington, Seattle, WA, USA. .,Department of Obstetrics and Gynaecology, CHU Ste-Justine Research Centre, University of Montreal, Montreal, QC, Canada. .,Department of Neurosciences, CHU Ste-Justine Research Centre, University of Montreal, Montreal, QC, Canada. .,Centre de Recherche en Reproduction Animale (CRRA), University of Montreal, St-Hyacinthe, QC, Canada.
| | - Patrick Burns
- Bristol Veterinary School, University of Bristol, Bristol, UK
| | - Javier Benito
- Faculty of Veterinary Medicine, Department of Clinical Sciences, University of Montreal, St-Hyacinthe, QC, Canada
| | - Marina Cortes
- Centre de Recherche en Reproduction Animale (CRRA), University of Montreal, St-Hyacinthe, QC, Canada
| | - Mingju Cao
- Department of Obstetrics and Gynaecology, CHU Ste-Justine Research Centre, University of Montreal, Montreal, QC, Canada.,Department of Neurosciences, CHU Ste-Justine Research Centre, University of Montreal, Montreal, QC, Canada
| | - Gilles Fecteau
- Faculty of Veterinary Medicine, Department of Clinical Sciences, University of Montreal, St-Hyacinthe, QC, Canada
| | - André Desrochers
- Faculty of Veterinary Medicine, Department of Clinical Sciences, University of Montreal, St-Hyacinthe, QC, Canada
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Haley MJ, Brough D, Quintin J, Allan SM. Microglial Priming as Trained Immunity in the Brain. Neuroscience 2017; 405:47-54. [PMID: 29292078 DOI: 10.1016/j.neuroscience.2017.12.039] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 11/09/2017] [Accepted: 12/20/2017] [Indexed: 12/22/2022]
Abstract
In this review we discuss the possibility that the phenomenon of microglial priming can be explained by the mechanisms that underlie trained immunity. The latter involves the enhancement of inflammatory responses by epigenetic mechanisms that are mobilized after first exposure to an inflammatory stimulus. These mechanisms include long-lasting histone modifications, including H3K4me1 deposition at latent enhancer regions. Although such changes may be beneficial in peripheral infectious disease, in the context of microglial priming they may drive increased microglia reactivity that is damaging in diseases of brain aging.
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Affiliation(s)
- Michael J Haley
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Manchester M13 9PT, UK
| | - David Brough
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Manchester M13 9PT, UK.
| | - Jessica Quintin
- Immunology of Fungal Infections Group, Department of Mycology, Institut Pasteur, 25 rue du Docteur Roux, Paris, France
| | - Stuart M Allan
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Manchester M13 9PT, UK
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Domínguez Rubio AP, Correa F, Aisemberg J, Dorfman D, Bariani MV, Rosenstein RE, Zorrilla Zubilete M, Franchi AM. Maternal administration of melatonin exerts short- and long-term neuroprotective effects on the offspring from lipopolysaccharide-treated mice. J Pineal Res 2017; 63. [PMID: 28776755 DOI: 10.1111/jpi.12439] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Accepted: 07/31/2017] [Indexed: 01/02/2023]
Abstract
Preterm birth is a major contributor to early and delayed physical and cognitive impairment. Epidemiological and experimental data indicate that maternal infections are a significant and preventable cause of preterm birth. Recently, melatonin has been suggested to exert neuroprotective effects in several models of brain injury. Here, we sought to investigate whether the administration of melatonin is able to prevent lipopolysaccharide (LPS)-induced fetal brain damage in a model of LPS-induced preterm labor. For this purpose, 15-day pregnant BALB/c mice received intraperitoneally 2 doses of LPS or vehicle: the first one at 10:00 hours (0.26 mg/kg) and the second at 13:00 hours (0.52 mg/kg). On day 14 of pregnancy, a group of mice was subcutaneously implanted with a pellet of 25 mg melatonin. This experimental protocol resulted in 100% of preterm birth and pup death in the LPS group and a 50% of term birth and pup survival in the melatonin + LPS group. In the absence of melatonin, fetuses from LPS-treated mothers showed histological signs of brain damage, microglial/macrophage activation, and higher levels of IL-1β, inducible nitric oxide synthase (NOS), and neuronal NOS mRNAs as well as increased histone acetyltransferase activity and histone H3 hyperacetylation. In contrast, antenatal administration of melatonin prevented LPS-induced fetal brain damage. Moreover, when behavioral traits were analyzed in the offspring from control, melatonin, and melatonin + LPS, no significant differences were found, suggesting that melatonin prevented LPS-induced long-term neurodevelopmental impairments. Collectively, our results suggest that melatonin could be a new therapeutic tool to prevent fetal brain damage and its long-term consequences induced by maternal inflammation.
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Affiliation(s)
- Ana Paula Domínguez Rubio
- Laboratorio de Fisiopatología de la Preñez y el Parto, Facultad de Medicina, Centro de Estudios Farmacológicos y Botánicos (CEFyBO), Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
| | - Fernando Correa
- Laboratorio de Fisiopatología de la Preñez y el Parto, Facultad de Medicina, Centro de Estudios Farmacológicos y Botánicos (CEFyBO), Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
| | - Julieta Aisemberg
- Laboratorio de Fisiopatología de la Preñez y el Parto, Facultad de Medicina, Centro de Estudios Farmacológicos y Botánicos (CEFyBO), Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
| | - Damián Dorfman
- Laboratorio de Neuroquimíca Retiniana y Oftalmología Experimental, Departamento de Bioquímica Humana, Facultad de Medicina, Centro de Estudios Farmacológicos y Botánicos (CEFyBO), Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
| | - María Victoria Bariani
- Laboratorio de Fisiopatología de la Preñez y el Parto, Facultad de Medicina, Centro de Estudios Farmacológicos y Botánicos (CEFyBO), Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
| | - Ruth Estela Rosenstein
- Laboratorio de Neuroquimíca Retiniana y Oftalmología Experimental, Departamento de Bioquímica Humana, Facultad de Medicina, Centro de Estudios Farmacológicos y Botánicos (CEFyBO), Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
| | - María Zorrilla Zubilete
- Laboratorio de Neuropsicofarmacología del Estrés, Departamento de Farmacología, Facultad de Medicina, Centro de Estudios Farmacológicos y Botánicos (CEFyBO), Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
| | - Ana María Franchi
- Laboratorio de Fisiopatología de la Preñez y el Parto, Facultad de Medicina, Centro de Estudios Farmacológicos y Botánicos (CEFyBO), Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
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Akhtar F, Rouse CA, Catano G, Montalvo M, Ullevig SL, Asmis R, Kharbanda K, Maffi SK. Acute maternal oxidant exposure causes susceptibility of the fetal brain to inflammation and oxidative stress. J Neuroinflammation 2017; 14:195. [PMID: 28962577 PMCID: PMC5622443 DOI: 10.1186/s12974-017-0965-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 09/18/2017] [Indexed: 12/18/2022] Open
Abstract
Background Maternal exposure to environmental stressors poses a risk to fetal development. Oxidative stress (OS), microglia activation, and inflammation are three tightly linked mechanisms that emerge as a causal factor of neurodevelopmental anomalies associated with prenatal ethanol exposure. Antioxidants such as glutathione (GSH) and CuZnSOD are perturbed, and their manipulation provides evidence for neuroprotection. However, the cellular and molecular effects of GSH alteration in utero on fetal microglia activation and inflammation remain elusive. Methods Ethanol (EtOH) (2.5 g/kg) was administered to pregnant mice at gestational days 16–17. One hour prior to ethanol treatment, N-acetylcysteine (NAC) and L-buthionine sulfoximine (BSO) were administered to modulate glutathione (GSH) content in fetal and maternal brain. Twenty-four hours following ethanol exposure, GSH content and OS in brain tissues were analyzed. Cytokines and chemokines were selected based on their association with distinctive microglia phenotype M1-like (IL-1β, IFN γ, IL-6, CCL3, CCL4, CCL-7, CCL9,) or M2-like (TGF-β, IL-4, IL-10, CCL2, CCL22, CXCL10, Arg1, Chi1, CCR2 and CXCR2) and measured in the brain by qRT-PCR and ELISA. In addition, Western blot and confocal microscopy techniques in conjunction with EOC13.31 cells exposed to similar ethanol-induced oxidative stress and redox conditions were used to determine the underlying mechanism of microglia activation associated with the observed phenotypic changes. Results We show that a single episode of mild to moderate OS in the last trimester of gestation causes GSH depletion, increased protein and lipid peroxidation and inflammatory responses inclined towards a M1-like microglial phenotype (IL-1β, IFN-γ) in fetal brain tissue observed at 6–24 h post exposure. Maternal brain is resistant to many of these marked changes. Using EOC 13.31 cells, we show that GSH homeostasis in microglia is crucial to restore its anti-inflammatory state and modulate inflammation. Microglia under oxidative stress maintain a predominantly M1 activation state. Additionally, GSH depletion prevents the appearance of the M2-like phenotype, while enhancing morphological changes associated with a M1-like phenotype. This observation is also validated by an increased expression of inflammatory signatures (IL-1β, IFN-γ, IL-6, CCL9, CXCR2). In contrast, conserving intracellular GSH concentrations eliminates OS which precludes the nuclear translocation and more importantly the phosphorylation of the NFkB p105 subunit. These cells show significantly more pronounced elongations, ramifications, and the enhanced expression of M2-like microglial phenotype markers (IL-10, IL-4, TGF-β, CXCL10, CCL22, Chi, Arg, and CCR2). Conclusions Taken together, our data show that maintaining GSH homeostasis is not only important for quenching OS in the developing fetal brain, but equally critical to enhance M2 like microglia phenotype, thus suppressing inflammatory responses elicited by environmental stressors. Electronic supplementary material The online version of this article (10.1186/s12974-017-0965-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Feroz Akhtar
- School of Medicine, Department of Biomedical Sciences, Regional Academic Health Center, University of Texas Rio Grande Valley, 1204 W. Schunior, Edinburg, 78241, TX, USA
| | - Christopher A Rouse
- Department of Pediatrics, Uniformed Services University of Health Sciences & Walter Reed National Military Medical Center, Jones Bridge Rd, Bethesda, MD, USA
| | - Gabriel Catano
- Department of Medicine, The University of Texas Health Science Center, San Antonio, TX, USA
| | - Marcus Montalvo
- School of Medicine, Department of Biomedical Sciences, Regional Academic Health Center, University of Texas Rio Grande Valley, 1204 W. Schunior, Edinburg, 78241, TX, USA
| | - Sarah L Ullevig
- Department of Kinesiology, Health, and Nutrition, University of Texas at San Antonio, San Antonio, TX, USA
| | - Reto Asmis
- Department of Clinical Lab Sciences, The University of Texas Health Science Center, San Antonio, TX, USA
| | - Kusum Kharbanda
- Department of Internal Medicine, University of Nebraska Health Science Center, Omaha, NE, USA
| | - Shivani K Maffi
- School of Medicine, Department of Biomedical Sciences, Regional Academic Health Center, University of Texas Rio Grande Valley, 1204 W. Schunior, Edinburg, 78241, TX, USA.
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α7 nicotinic acetylcholine receptor signaling modulates the inflammatory phenotype of fetal brain microglia: first evidence of interference by iron homeostasis. Sci Rep 2017; 7:10645. [PMID: 28878260 PMCID: PMC5587535 DOI: 10.1038/s41598-017-09439-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Accepted: 07/26/2017] [Indexed: 12/17/2022] Open
Abstract
Neuroinflammation in utero may result in life-long neurological disabilities. Microglia play a pivotal role, but the mechanisms are poorly understood. No early postnatal treatment strategies exist to enhance neuroprotective potential of microglia. We hypothesized that agonism on α7 nicotinic acetylcholine receptor (α7nAChR) in fetal microglia will augment their neuroprotective transcriptome profile, while the antagonistic stimulation of α7nAChR will achieve the opposite. Using an in vivo - in vitro model of developmental programming of neuroinflammation induced by lipopolysaccharide (LPS), we validated this hypothesis in primary fetal sheep microglia cultures re-exposed to LPS in presence of a selective α7nAChR agonist or antagonist. Our RNAseq and protein level findings show that a pro-inflammatory microglial phenotype acquired in vitro by LPS stimulation is reversed with α7nAChR agonistic stimulation. Conversely, antagonistic α7nAChR stimulation potentiates the pro-inflammatory microglial phenotype. Surprisingly, under conditions of LPS double-hit an interference of a postulated α7nAChR - ferroportin signaling pathway may impede this mechanism. These results suggest a therapeutic potential of α7nAChR agonists in early re-programming of microglia in neonates exposed to in utero inflammation via an endogenous cerebral cholinergic anti-inflammatory pathway. Future studies will assess the role of interactions between inflammation-triggered microglial iron sequestering and α7nAChR signaling in neurodevelopment.
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Gussenhoven R, Ophelders DRMG, Kemp MW, Payne MS, Spiller OB, Beeton ML, Stock SJ, Cillero-Pastor B, Barré FPY, Heeren RMA, Kessels L, Stevens B, Rutten BP, Kallapur SG, Jobe AH, Kramer BW, Wolfs TGAM. The Paradoxical Effects of Chronic Intra-Amniotic Ureaplasma parvum Exposure on Ovine Fetal Brain Development. Dev Neurosci 2017; 39:472-486. [PMID: 28848098 DOI: 10.1159/000479021] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Accepted: 06/24/2017] [Indexed: 01/23/2023] Open
Abstract
Chorioamnionitis is associated with adverse neurodevelopmental outcomes in preterm infants. Ureaplasma spp. are the microorganisms most frequently isolated from the amniotic fluid of women diagnosed with chorioamnionitis. However, controversy remains concerning the role of Ureaplasma spp. in the pathogenesis of neonatal brain injury. We hypothesize that reexposure to an inflammatory trigger during the perinatal period might be responsible for the variation in brain outcomes of preterms following Ureaplasma-driven chorioamnionitis. To investigate these clinical scenarios, we performed a detailed multimodal study in which ovine neurodevelopmental outcomes were assessed following chronic intra-amniotic Ureaplasma parvum (UP) infection either alone or combined with subsequent lipopolysaccharide (LPS) exposure. We show that chronic intra-amniotic UP exposure during the second trimester provoked a decrease in astrocytes, increased oligodendrocyte numbers, and elevated 5-methylcytosine levels. In contrast, short-term LPS exposure before preterm birth induced increased microglial activation, myelin loss, elevation of 5-hydroxymethylcytosine levels, and lipid profile changes. These LPS-induced changes were prevented by chronic preexposure to UP (preconditioning). These data indicate that chronic UP exposure has dual effects on preterm brain development in utero. On the one hand, prolonged UP exposure causes detrimental cerebral changes that may predispose to adverse postnatal clinical outcomes. On the other, chronic intra-amniotic UP exposure preconditions the brain against a second inflammatory hit. This study demonstrates that microbial interactions and the timing and duration of the inflammatory insults determine the effects on the fetal brain. Therefore, this study helps to understand the complex and diverse postnatal neurological outcomes following UP driven chorioamnionitis.
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Affiliation(s)
- Ruth Gussenhoven
- Department of Pediatrics, Maastricht University Medical Center, Maastricht, The Netherlands
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Mosser CA, Baptista S, Arnoux I, Audinat E. Microglia in CNS development: Shaping the brain for the future. Prog Neurobiol 2017; 149-150:1-20. [DOI: 10.1016/j.pneurobio.2017.01.002] [Citation(s) in RCA: 158] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Revised: 01/24/2017] [Accepted: 01/24/2017] [Indexed: 12/22/2022]
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30
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Cortes M, Cao M, Liu HL, Burns P, Moore C, Fecteau G, Desrochers A, Barreiro LB, Antel JP, Frasch MG. RNAseq profiling of primary microglia and astrocyte cultures in near-term ovine fetus: A glial in vivo-in vitro multi-hit paradigm in large mammalian brain. J Neurosci Methods 2016; 276:23-32. [PMID: 27856275 DOI: 10.1016/j.jneumeth.2016.11.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Revised: 11/10/2016] [Accepted: 11/11/2016] [Indexed: 12/22/2022]
Abstract
BACKGROUND The chronically instrumented fetal sheep is a widely used animal model to study fetal brain development in health and disease, but no methods exist yet to interrogate dedicated brain cell populations to identify their molecular and genomic phenotype. For example, the molecular mechanisms whereby microglia or astrocytes contribute to inflammation in the brain remain incompletely understood. NEW METHOD Here we present a protocol to derive primary pure microglial or astrocyte cultures from near-term fetal sheep brain, after the animals have been chronically instrumented and studied in vivo. Next, we present the implementation of whole transcriptome sequencing (RNAseq) pipeline to deeper elucidate the phenotype of such primary sheep brain glial cultures. RESULTS We validate the new primary cultures method for cell purity and test the function of the glial cells on protein (IL-1β) and transcriptome (RNAseq) levels in response to a lipopolysaccharide (LPS) challenge in vitro. COMPARISON WITH EXISTING METHODS This method represents the first implementation of pure microglial or astrocytes cultures in fetal sheep brain. CONCLUSIONS The presented approach opens new possibilities for testing not only supernatant protein levels in response to an in vitro challenge, but also to evaluate changes in the transcriptome of glial cells derived from a large mammalian brain bearing high resemblance to the human brain. Moreover, the presented approach lends itself to modeling the complex multi-hit paradigms of antenatal and perinatal cerebral insults in vivo and in vitro.
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Affiliation(s)
- M Cortes
- Animal Reproduction Research Centre (CRRA), Faculty of Veterinary Medicine, Université de Montréal, Montréal, QC, Canada
| | - M Cao
- Department of Obstetrics and Gynaecology and Department of Neurosciences, CHU Ste.-Justine Research Centre, Faculty of Medicine, Université de Montréal, Montréal, QC, Canada
| | - H L Liu
- Department of Obstetrics and Gynaecology and Department of Neurosciences, CHU Ste.-Justine Research Centre, Faculty of Medicine, Université de Montréal, Montréal, QC, Canada
| | - P Burns
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Université de Montréal, QC, Canada
| | - C Moore
- Neuroimmunology Unit, Montréal Neurological Institute, McGill University, Montréal, QC, Canada
| | - G Fecteau
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Université de Montréal, QC, Canada
| | - A Desrochers
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Université de Montréal, QC, Canada
| | - L B Barreiro
- Department of Pediatrics, CHU Ste.-Justine Research Centre, Faculty of Medicine, Université de Montréal, Montréal, QC, Canada
| | - J P Antel
- Neuroimmunology Unit, Montréal Neurological Institute, McGill University, Montréal, QC, Canada
| | - M G Frasch
- Animal Reproduction Research Centre (CRRA), Faculty of Veterinary Medicine, Université de Montréal, Montréal, QC, Canada; Department of Obstetrics and Gynaecology and Department of Neurosciences, CHU Ste.-Justine Research Centre, Faculty of Medicine, Université de Montréal, Montréal, QC, Canada.
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31
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Barger SW. Gene regulation and genetics in neurochemistry, past to future. J Neurochem 2016; 139 Suppl 2:24-57. [PMID: 27747882 DOI: 10.1111/jnc.13629] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2015] [Revised: 03/01/2016] [Accepted: 03/30/2016] [Indexed: 12/14/2022]
Abstract
Ask any neuroscientist to name the most profound discoveries in the field in the past 60 years, and at or near the top of the list will be a phenomenon or technique related to genes and their expression. Indeed, our understanding of genetics and gene regulation has ushered in whole new systems of knowledge and new empirical approaches, many of which could not have even been imagined prior to the molecular biology boon of recent decades. Neurochemistry, in the classic sense, intersects with these concepts in the manifestation of neuropeptides, obviously dependent upon the central dogma (the established rules by which DNA sequence is eventually converted into protein primary structure) not only for their conformation but also for their levels and locales of expression. But, expanding these considerations to non-peptide neurotransmitters illustrates how gene regulatory events impact neurochemistry in a much broader sense, extending beyond the neurochemicals that translate electrical signals into chemical ones in the synapse, to also include every aspect of neural development, structure, function, and pathology. From the beginning, the mutability - yet relative stability - of genes and their expression patterns were recognized as potential substrates for some of the most intriguing phenomena in neurobiology - those instances of plasticity required for learning and memory. Near-heretical speculation was offered in the idea that perhaps the very sequence of the genome was altered to encode memories. A fascinating component of the intervening progress includes evidence that the central dogma is not nearly as rigid and consistent as we once thought. And this mutability extends to the potential to manipulate that code for both experimental and clinical purposes. Astonishing progress has been made in the molecular biology of neurochemistry during the 60 years since this journal debuted. Many of the gains in conceptual understanding have been driven by methodological progress, from automated high-throughput sequencing instruments to recombinant-DNA vectors that can convey color-coded genetic modifications in the chromosomes of live adult animals. This review covers the highlights of these advances, both theoretical and technological, along with a brief window into the promising science ahead. This article is part of the 60th Anniversary special issue.
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Affiliation(s)
- Steven W Barger
- Department of Geriatrics, Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA. .,Geriatric Research Education and Clinical Center, Central Arkansas Veterans Healthcare System, Little Rock, Arkansas, USA.
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Hoeijmakers L, Heinen Y, van Dam AM, Lucassen PJ, Korosi A. Microglial Priming and Alzheimer's Disease: A Possible Role for (Early) Immune Challenges and Epigenetics? Front Hum Neurosci 2016; 10:398. [PMID: 27555812 PMCID: PMC4977314 DOI: 10.3389/fnhum.2016.00398] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 07/26/2016] [Indexed: 12/11/2022] Open
Abstract
Neuroinflammation is thought to contribute to Alzheimer's disease (AD) pathogenesis that is, to a large extent, mediated by microglia. Given the tight interaction between the immune system and the brain, peripheral immune challenges can profoundly affect brain function. Indeed, both preclinical and clinical studies have indicated that an aberrant inflammatory response can elicit behavioral impairments and cognitive deficits, especially when the brain is in a vulnerable state, e.g., during early development, as a result of aging, or under disease conditions like AD. However, how exactly peripheral immune challenges affect brain function and whether this is mediated by aberrant microglial functioning remains largely elusive. In this review, we hypothesize that: (1) systemic immune challenges occurring during vulnerable periods of life can increase the propensity to induce later cognitive dysfunction and accelerate AD pathology; and (2) that "priming" of microglial cells is instrumental in mediating this vulnerability. We highlight how microglia can be primed by both neonatal infections as well as by aging, two periods of life during which microglial activity is known to be specifically upregulated. Lasting changes in (the ratios of) specific microglial phenotypes can result in an exaggerated pro-inflammatory cytokine response to subsequent inflammatory challenges. While the resulting changes in brain function are initially transient, a continued and/or excess release of such pro-inflammatory cytokines can activate various downstream cellular cascades known to be relevant for AD. Finally, we discuss microglial priming and the aberrant microglial response as potential target for treatment strategies for AD.
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Affiliation(s)
- Lianne Hoeijmakers
- Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam Amsterdam, Netherlands
| | - Yvonne Heinen
- Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam Amsterdam, Netherlands
| | - Anne-Marie van Dam
- Department of Anatomy and Neurosciences, Neuroscience Campus Amsterdam, VU University Medical Center Amsterdam, Netherlands
| | - Paul J Lucassen
- Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam Amsterdam, Netherlands
| | - Aniko Korosi
- Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam Amsterdam, Netherlands
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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] [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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Frasch MG, Szynkaruk M, Prout AP, Nygard K, Cao M, Veldhuizen R, Hammond R, Richardson BS. Decreased neuroinflammation correlates to higher vagus nerve activity fluctuations in near-term ovine fetuses: a case for the afferent cholinergic anti-inflammatory pathway? J Neuroinflammation 2016; 13:103. [PMID: 27165310 PMCID: PMC4894374 DOI: 10.1186/s12974-016-0567-x] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Accepted: 05/02/2016] [Indexed: 12/18/2022] Open
Abstract
Background Neuroinflammation in utero may contribute to brain injury resulting in life-long neurological disabilities. The pivotal role of the efferent cholinergic anti-inflammatory pathway (CAP) in controlling inflammation, e.g., by inhibiting the HMGB1 release, via the macrophages’ α7 nicotinic acetylcholine receptor (α7nAChR) has been described in adults, but its importance in the fetus is unknown. Moreover, it is unknown whether CAP may also exert anti-inflammatory effects on the brain via the anatomically predominant afferent component of the vagus nerve. Methods We measured microglial activation in the ovine fetal brain near term 24 h after the umbilical cord occlusions mimicking human labor versus controls (no occlusions) by quantifying HMGB1 nucleus-to-cytosol translocation in the Iba1+ and α7nAChR+ microglia. Based on multiple clinical studies in adults and our own work in fetal autonomic nervous system, we gauged the degree of CAP activity in vivo using heart rate variability measure RMSSD that reflects fluctuations in vagus nerve activity. Results RMSSD correlated to corresponding plasma IL-1β levels at R = 0.57 (p = 0.02, n = 17) and to white matter microglia cell counts at R = −0.89 (p = 0.03). The insult increased the HMGB1 translocation in α7nAChR+ microglia in a brain region-dependent manner (p < 0.001). In parallel, RMSSD at 1 h post insult correlated with cytosolic HMGB1 of thalamic microglia (R = −0.94, p = 0.005), and RMSSD at pH nadir correlated with microglial α7nAChR in the white matter (R = 0.83, p = 0.04). Overall, higher RMSSD values correlated with lower HMGB1 translocation and higher α7nAChR intensity per area in a brain region-specific manner. Conclusions Afferent fetal CAP may translate increased vagal cholinergic signaling into suppression of cerebral inflammation in response to near-term hypoxic acidemia as might occur during labor. Our findings suggest a new control mechanism of fetal neuroinflammation via the vagus nerve, providing novel possibilities for its non-invasive monitoring in utero and for targeted treatment. Electronic supplementary material The online version of this article (doi:10.1186/s12974-016-0567-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- M G Frasch
- Department of Obstetrics and Gynaecology, CHU Ste-Justine Research Centre, Faculty of Medicine, Université de Montréal, Montréal, QC, Canada. .,Department of Neurosciences, CHU Ste-Justine Research Centre, Faculty of Medicine, Université de Montréal, Montréal, QC, Canada. .,Animal Reproduction Research Centre (CRRA), Faculty of Veterinary Medicine, Université de Montréal, Montréal, QC, Canada. .,Department of Obstetrics and Gynaecology, Lawson Health Research Institute, University of Western Ontario, London, ON, Canada. .,Department of Obstetrics and Gynecology, University of Washington, 1959 NE Pacific St, Box 356460, Seattle, WA, 98195, USA.
| | - M Szynkaruk
- Department of Obstetrics and Gynaecology, Lawson Health Research Institute, University of Western Ontario, London, ON, Canada
| | - A P Prout
- Department of Obstetrics and Gynaecology, Lawson Health Research Institute, University of Western Ontario, London, ON, Canada
| | - K Nygard
- Microscopy Imaging@Biotron, University of Western Ontario, London, ON, Canada
| | - M Cao
- Department of Obstetrics and Gynaecology, CHU Ste-Justine Research Centre, Faculty of Medicine, Université de Montréal, Montréal, QC, Canada.,Department of Neurosciences, CHU Ste-Justine Research Centre, Faculty of Medicine, Université de Montréal, Montréal, QC, Canada
| | - R Veldhuizen
- Department of Physiology and Pharmacology, University of Western Ontario, London, ON, Canada
| | - R Hammond
- Department of Pathology, University of Western Ontario, London, ON, Canada
| | - B S Richardson
- Department of Obstetrics and Gynaecology, Lawson Health Research Institute, University of Western Ontario, London, ON, Canada.,Department of Physiology and Pharmacology, University of Western Ontario, London, ON, Canada
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Can Monitoring Fetal Intestinal Inflammation Using Heart Rate Variability Analysis Signal Incipient Necrotizing Enterocolitis of the Neonate? Pediatr Crit Care Med 2016; 17:e165-76. [PMID: 26914621 DOI: 10.1097/pcc.0000000000000643] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
OBJECTIVE Necrotizing enterocolitis of the neonate is an acute inflammatory intestinal disease that can cause necrosis and sepsis. Chorioamnionitis is a risk factor of necrotizing enterocolitis. The gut represents the biggest vagus-innervated organ. Vagal activity can be measured via fetal heart rate variability. We hypothesized that fetal heart rate variability can detect fetuses with incipient gut inflammation. DESIGN Prospective animal study. SETTING University research laboratory. SUBJECTS Chronically instrumented near-term fetal sheep (n = 21). MEASUREMENTS AND MAIN RESULTS Animals were surgically instrumented with vascular catheters and electrocardiogram to allow manipulation and recording from nonanesthetized animals. In 14 fetal sheep, inflammation was induced with lipopolysaccharide (IV) to mimic chorioamnionitis. Fetal arterial blood samples were drawn at selected time points over 54 hours post lipopolysaccharide for blood gas and cytokines (interleukin-6 and tumor necrosis factor-α enzymelinked immunosorbent assay). Fetal heart rateV was quantified throughout the experiment. The time-matched fetal heart rate variability measures were correlated to the levels of interleukin-6 and tumor necrosis factor-α. Upon necropsy, ionized calcium binding adaptor molecule 1+ (Iba1+), CD11c+ (M1), CD206+ (M2 macrophages), and occludin (leakiness marker) immunofluorescence in the terminal ileum was quantified along with regional Iba1+ signal in the brain (microglia). Interleukin-6 peaked at 3 hours post lipopolysaccharide accompanied by mild cardiovascular signs of sepsis. At 54 hours, we identified an increase in Iba1+ and, specifically, M1 macrophages in the ileum accompanied by increased leakiness, with no change in Iba1 signal in the brain. Preceding this change on tissue level, at 24 hours, a subset of nine fetal heart rate variability measures correlated exclusively to the Iba+ markers of ileal, but not brain, inflammation. An additional fetal heart rate variability measure, mean of the differences of R-R intervals, correlated uniquely to M1 ileum macrophages increasing due to lipopolysaccharide. CONCLUSIONS We identified a unique subset of fetal heart rate variability measures reflecting 1.5 days ahead of time the levels of macrophage activation and increased leakiness in terminal ileum. We propose that such subset of fetal heart rate variability measures reflects brain-gut communication via the vagus nerve. Detecting such noninvasively obtainable organ-specific fetal heart rate variability signature of inflammation would alarm neonatologists about neonates at risk of developing necrotizing enterocolitis and sepsis. Clinical validation studies are required.
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