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Augusto-Oliveira M, Tremblay MÈ, Verkhratsky A. Receptors on Microglia. ADVANCES IN NEUROBIOLOGY 2024; 37:83-121. [PMID: 39207688 DOI: 10.1007/978-3-031-55529-9_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/04/2024]
Abstract
Microglial cells are the most receptive cells in the central nervous system (CNS), expressing several classes of receptors reflecting their immune heritage and newly acquired neural specialisation. Microglia possess, depending on the particular context, receptors to neurotransmitters and neuromodulators as well as immunocompetent receptors. This rich complement allows microglial cells to monitor the functional status of the nervous system, contribute actively to the regulation of neural activity and plasticity and homeostasis, and guard against pathogens as well as other challenges to the CNS's integrity and function.
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Affiliation(s)
- Marcus Augusto-Oliveira
- Laboratório de Farmacologia Molecular, Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, Brazil
- Programa de Pós-Graduação em Farmacologia e Bioquímica, Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, Brazil
| | - Marie-Ève Tremblay
- Division of Medical Sciences, Medical Sciences Building, University of Victoria, Victoria, BC, Canada
- Axe neurosciences, Centre de recherche du CHU de Québec-Université Laval, Québec City, QC, Canada
- Neurology and Neurosurgery Department, McGill University, Montreal, QC, Canada
- Department of Molecular Medicine, Université Laval, Pavillon Ferdinand-Vandry, Québec City, QC, Canada
- Department of Biochemistry and Molecular Biology, The University of British Columbia, Life Sciences Center, Vancouver, BC, Canada
| | - Alexei Verkhratsky
- Faculty of Life Sciences, The University of Manchester, Manchester, UK.
- Department of Neurosciences, University of the Basque Country, Leioa, Spain.
- IKERBASQUE, Basque Foundation for Science, Bilbao, Spain.
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2
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Pfeifer CW, Walsh JT, Santeford A, Lin JB, Beatty WL, Terao R, Liu YA, Hase K, Ruzycki PA, Apte RS. Dysregulated CD200-CD200R signaling in early diabetes modulates microglia-mediated retinopathy. Proc Natl Acad Sci U S A 2023; 120:e2308214120. [PMID: 37903272 PMCID: PMC10636339 DOI: 10.1073/pnas.2308214120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Accepted: 09/25/2023] [Indexed: 11/01/2023] Open
Abstract
Diabetic retinopathy (DR) is a neurovascular complication of diabetes. Recent investigations have suggested that early degeneration of the neuroretina may occur prior to the appearance of microvascular changes; however, the mechanisms underlying this neurodegeneration have been elusive. Microglia are the predominant resident immune cell in the retina and adopt dynamic roles in disease. Here, we show that ablation of retinal microglia ameliorates visual dysfunction and neurodegeneration in a type I diabetes mouse model. We also provide evidence of enhanced microglial contact and engulfment of amacrine cells, ultrastructural modifications, and transcriptome changes that drive inflammation and phagocytosis. We show that CD200-CD200R signaling between amacrine cells and microglia is dysregulated during early DR and that targeting CD200R can attenuate high glucose-induced inflammation and phagocytosis in cultured microglia. Last, we demonstrate that targeting CD200R in vivo can prevent visual dysfunction, microglia activation, and retinal inflammation in the diabetic mouse. These studies provide a molecular framework for the pivotal role that microglia play in early DR pathogenesis and identify a potential immunotherapeutic target for treating DR in patients.
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Affiliation(s)
- Charles W. Pfeifer
- John F. Hardesty, Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO63110
- Neurosciences Graduate Program, Roy and Diana Vagelos Division of Biology and Biomedical Sciences, Washington University School of Medicine, St. Louis, MO63110
| | - James T. Walsh
- John F. Hardesty, Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO63110
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO63110
| | - Andrea Santeford
- John F. Hardesty, Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO63110
| | - Joseph B. Lin
- John F. Hardesty, Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO63110
- Neurosciences Graduate Program, Roy and Diana Vagelos Division of Biology and Biomedical Sciences, Washington University School of Medicine, St. Louis, MO63110
| | - Wandy L. Beatty
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO63110
| | - Ryo Terao
- John F. Hardesty, Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO63110
- Department of Ophthalmology, Graduate School of Medicine, The University of Tokyo, Tokyo1138665, Japan
| | - Yizhou A. Liu
- John F. Hardesty, Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO63110
| | - Keitaro Hase
- John F. Hardesty, Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO63110
| | - Philip A. Ruzycki
- John F. Hardesty, Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO63110
- Department of Genetics, Washington University School of Medicine, St. Louis, MO63110
| | - Rajendra S. Apte
- John F. Hardesty, Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO63110
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO63110
- Department of Medicine, Washington University School of Medicine, St. Louis, MO63110
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3
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Neha, Parvez S. Emerging therapeutics agents and recent advances in drug repurposing for Alzheimer's disease. Ageing Res Rev 2023; 85:101815. [PMID: 36529440 DOI: 10.1016/j.arr.2022.101815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2022] [Revised: 11/29/2022] [Accepted: 12/01/2022] [Indexed: 12/23/2022]
Abstract
Alzheimer's disease (AD) is a multivariate and diversified disease and affects the most sensitive areas of the brain, the cerebral cortex, and the hippocampus. AD is a progressive age-related neurodegenerative disease most often associated with memory deficits and cognition that get more worsen over time. The central theory on the pathophysiological hallmark features of AD is characterized by the accumulation of amyloid β (Aβ) peptides, also associated with tau proteins (τ) dysfunctioning which leads to distorted microtubular structure, affects the cholinergic system, and mitochondrial biogenesis. This review emphasizes how simple it is to find novel treatments for AD and focuses on several recently developed medications through repurposing that can speed up traditional drug development.
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Affiliation(s)
- Neha
- Department of Toxicology, School of Chemical and Life Sciences, Jamia Hamdard, New Delhi 110062, India
| | - Suhel Parvez
- Department of Toxicology, School of Chemical and Life Sciences, Jamia Hamdard, New Delhi 110062, India.
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4
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Khan SR, Yaqub A, Ikram MK, van Hagen PM, Peeters RP, Dalm VASH, Chaker L, Ikram MA. The association of serum immunoglobulins with cognition and dementia: the Rotterdam Study. J Neurol 2023; 270:423-432. [PMID: 36123443 DOI: 10.1007/s00415-022-11374-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Accepted: 09/06/2022] [Indexed: 01/07/2023]
Abstract
BACKGROUND Chronic inflammation is involved in the pathophysiology of dementia, but the association of serum immunoglobulins with dementia has been understudied and longitudinal data are currently lacking. We investigated the association of serum immunoglobulin (Ig) A, G, and M with cognition and dementia in a population-based cohort. METHODS This study was embedded in the Rotterdam Study. Participants with information on serum immunoglobulin levels, measured between 1997 and 2009, were followed for incident dementia until 2016. Assessment of cognitive function and dementia was performed according to validated tests and clinical criteria respectively. We studied the association between serum immunoglobulins with prevalent and incident dementia using logistic regression and Cox proportional hazards regression analyses respectively. We performed linear regression analyses to quantify the cross-sectional association of serum immunoglobulins with global cognition as well as separate cognitive tests. Analyses were adjusted for age, sex, lifestyle, and cardiovascular factors. RESULTS We included 8768 participants (median age of 62.2 years, 57% women, median follow-up 10.7 years). Overall, none of the immunoglobulins was associated with prevalent or incident dementia. Higher IgG levels were associated with lower scores of global cognition (adjusted standardized mean difference - 0.04; 95% confidence interval:- 0.06; - 0.02) and separate cognitive tests. CONCLUSION In middle-aged and older individuals from the general population, serum Igs were not associated with prevalent or incident dementia, which may imply that serum Igs are not involved in the pathophysiology of dementia. Although higher IgG levels were associated with worse cognitive function, studies with longitudinal data should exclude reverse causation.
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Affiliation(s)
- Samer R Khan
- Department of Epidemiology, Erasmus University Medical Center Rotterdam, PO Box 2040, 3000 CA, Rotterdam, The Netherlands.,Division of Allergy and Clinical Immunology, Department of Internal Medicine, Erasmus University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Amber Yaqub
- Department of Epidemiology, Erasmus University Medical Center Rotterdam, PO Box 2040, 3000 CA, Rotterdam, The Netherlands
| | - M Kamran Ikram
- Department of Epidemiology, Erasmus University Medical Center Rotterdam, PO Box 2040, 3000 CA, Rotterdam, The Netherlands.,Department of Neurology, Erasmus University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - P Martin van Hagen
- Division of Allergy and Clinical Immunology, Department of Internal Medicine, Erasmus University Medical Center Rotterdam, Rotterdam, The Netherlands.,Department of Immunology, Erasmus University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Robin P Peeters
- Department of Epidemiology, Erasmus University Medical Center Rotterdam, PO Box 2040, 3000 CA, Rotterdam, The Netherlands.,Division of Endocrinology, Department of Internal Medicine, Erasmus University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Virgil A S H Dalm
- Division of Allergy and Clinical Immunology, Department of Internal Medicine, Erasmus University Medical Center Rotterdam, Rotterdam, The Netherlands.,Department of Immunology, Erasmus University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Layal Chaker
- Department of Epidemiology, Erasmus University Medical Center Rotterdam, PO Box 2040, 3000 CA, Rotterdam, The Netherlands.,Division of Endocrinology, Department of Internal Medicine, Erasmus University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - M Arfan Ikram
- Department of Epidemiology, Erasmus University Medical Center Rotterdam, PO Box 2040, 3000 CA, Rotterdam, The Netherlands.
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5
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Kim DW, Tu KJ, Wei A, Lau AJ, Gonzalez-Gil A, Cao T, Braunstein K, Ling JP, Troncoso JC, Wong PC, Blackshaw S, Schnaar RL, Li T. Amyloid-beta and tau pathologies act synergistically to induce novel disease stage-specific microglia subtypes. Mol Neurodegener 2022; 17:83. [PMID: 36536457 PMCID: PMC9762062 DOI: 10.1186/s13024-022-00589-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 12/06/2022] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Amongst risk alleles associated with late-onset Alzheimer's disease (AD), those that converged on the regulation of microglia activity have emerged as central to disease progression. Yet, how canonical amyloid-β (Aβ) and tau pathologies regulate microglia subtypes during the progression of AD remains poorly understood. METHODS We use single-cell RNA-sequencing to profile microglia subtypes from mice exhibiting both Aβ and tau pathologies across disease progression. We identify novel microglia subtypes that are induced in response to both Aβ and tau pathologies in a disease-stage-specific manner. To validate the observation in AD mouse models, we also generated a snRNA-Seq dataset from the human superior frontal gyrus (SFG) and entorhinal cortex (ERC) at different Braak stages. RESULTS We show that during early-stage disease, interferon signaling induces a subtype of microglia termed Early-stage AD-Associated Microglia (EADAM) in response to both Aβ and tau pathologies. During late-stage disease, a second microglia subtype termed Late-stage AD-Associated Microglia (LADAM) is detected. While similar microglia subtypes are observed in other models of neurodegenerative disease, the magnitude and composition of gene signatures found in EADAM and LADAM are distinct, suggesting the necessity of both Aβ and tau pathologies to elicit their emergence. Importantly, the pattern of EADAM- and LADAM-associated gene expression is observed in microglia from AD brains, during the early (Braak II)- or late (Braak VI/V)- stage of the disease, respectively. Furthermore, we show that several Siglec genes are selectively expressed in either EADAM or LADAM. Siglecg is expressed in white-matter-associated LADAM, and expression of Siglec-10, the human orthologue of Siglecg, is progressively elevated in an AD-stage-dependent manner but not shown in non-AD tauopathy. CONCLUSIONS Using scRNA-Seq in mouse models bearing amyloid-β and/or tau pathologies, we identify novel microglia subtypes induced by the combination of Aβ and tau pathologies in a disease stage-specific manner. Our findings suggest that both Aβ and tau pathologies are required for the disease stage-specific induction of EADAM and LADAM. In addition, we revealed Siglecs as biomarkers of AD progression and potential therapeutic targets.
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Affiliation(s)
- Dong Won Kim
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205 USA
| | - Kevin J. Tu
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21205 USA
| | - Alice Wei
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21205 USA
| | - Ashley J. Lau
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21205 USA
| | - Anabel Gonzalez-Gil
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205 USA
| | - Tianyu Cao
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21205 USA
| | - Kerstin Braunstein
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21205 USA
| | - Jonathan P. Ling
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21205 USA
| | - Juan C. Troncoso
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21205 USA
| | - Philip C. Wong
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205 USA
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21205 USA
| | - Seth Blackshaw
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205 USA
| | - Ronald L. Schnaar
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205 USA
| | - Tong Li
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21205 USA
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6
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Matsuno H, Tsuchimine S, O'Hashi K, Sakai K, Hattori K, Hidese S, Nakajima S, Chiba S, Yoshimura A, Fukuzato N, Kando M, Tatsumi M, Ogawa S, Ichinohe N, Kunugi H, Sohya K. Association between vascular endothelial growth factor-mediated blood-brain barrier dysfunction and stress-induced depression. Mol Psychiatry 2022; 27:3822-3832. [PMID: 35618888 DOI: 10.1038/s41380-022-01618-3] [Citation(s) in RCA: 42] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 04/22/2022] [Accepted: 05/10/2022] [Indexed: 02/08/2023]
Abstract
Several lines of evidence suggest that stress induces the neurovascular dysfunction associated with increased blood-brain barrier (BBB) permeability, which could be an important pathology linking stress and psychiatric disorders, including major depressive disorder (MDD). However, the detailed mechanism resulting in BBB dysfunction associated in the pathophysiology of MDD still remains unclear. Herein, we demonstrate the role of vascular endothelial growth factor (VEGF), a key mediator of vascular angiogenesis and BBB permeability, in stress-induced BBB dysfunction and depressive-like behavior development. We implemented an animal model of depression, chronic restraint stress (RS) in BALB/c mice, and found that the BBB permeability was significantly increased in chronically stressed mice. Immunohistochemical and electron microscopic observations revealed that increased BBB permeability was associated with both paracellular and transcellular barrier alterations in the brain endothelial cells. Pharmacological inhibition of VEGF receptor 2 (VEGFR2) using a specific monoclonal antibody (DC101) prevented chronic RS-induced BBB permeability and anhedonic behavior. Considered together, these results indicate that VEGF/VEGFR2 plays a crucial role in the pathogenesis of depression by increasing the BBB permeability, and suggest that VEGFR2 inhibition could be a potential therapeutic strategy for the MDD subtype associated with BBB dysfunction.
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Affiliation(s)
- Hitomi Matsuno
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), 4-1-1 Ogawa-Higashi, Kodaira, Tokyo, 187-8502, Japan.
| | - Shoko Tsuchimine
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), 4-1-1 Ogawa-Higashi, Kodaira, Tokyo, 187-8502, Japan
| | - Kazunori O'Hashi
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), 4-1-1 Ogawa-Higashi, Kodaira, Tokyo, 187-8502, Japan.,Department of Pharmacology, Nihon University School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo, 101-8310, Japan
| | - Kazuhisa Sakai
- Department of Ultrastructural Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), 4-1-1 Ogawa-Higashi, Kodaira, Tokyo, 187-8502, Japan
| | - Kotaro Hattori
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), 4-1-1 Ogawa-Higashi, Kodaira, Tokyo, 187-8502, Japan
| | - Shinsuke Hidese
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), 4-1-1 Ogawa-Higashi, Kodaira, Tokyo, 187-8502, Japan.,Department of Psychiatry, Teikyo University School of Medicine, 2-11-1, Kaga, Itabashi-ku, Tokyo, 173-8605, Japan
| | - Shingo Nakajima
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), 4-1-1 Ogawa-Higashi, Kodaira, Tokyo, 187-8502, Japan.,Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal Diabetes Research Center, Montreal, QC, H2X 0A9, Canada
| | - Shuichi Chiba
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), 4-1-1 Ogawa-Higashi, Kodaira, Tokyo, 187-8502, Japan.,Faculty of Veterinary Medical Science, Okayama University of Science, 1-1 Ridaicho, Kita-ku, Okayama-shi, Okayama, 700-0005, Japan
| | - Aya Yoshimura
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), 4-1-1 Ogawa-Higashi, Kodaira, Tokyo, 187-8502, Japan.,Education and Research Center of Animal Models for Human Diseases, Fujita Health University, Toyoake, Aichi, 470-1192, Japan
| | - Noriko Fukuzato
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), 4-1-1 Ogawa-Higashi, Kodaira, Tokyo, 187-8502, Japan
| | - Mayumi Kando
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), 4-1-1 Ogawa-Higashi, Kodaira, Tokyo, 187-8502, Japan
| | - Megumi Tatsumi
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), 4-1-1 Ogawa-Higashi, Kodaira, Tokyo, 187-8502, Japan
| | - Shintaro Ogawa
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), 4-1-1 Ogawa-Higashi, Kodaira, Tokyo, 187-8502, Japan.,Department of Behavioral Medicine, National Institute of Mental Health, National Center of Neurology and Psychiatry, 4-1-1 Ogawa-Higashi, Kodaira, Tokyo, 187-8502, Japan
| | - Noritaka Ichinohe
- Department of Ultrastructural Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), 4-1-1 Ogawa-Higashi, Kodaira, Tokyo, 187-8502, Japan
| | - Hiroshi Kunugi
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), 4-1-1 Ogawa-Higashi, Kodaira, Tokyo, 187-8502, Japan.,Department of Psychiatry, Teikyo University School of Medicine, 2-11-1, Kaga, Itabashi-ku, Tokyo, 173-8605, Japan
| | - Kazuhiro Sohya
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), 4-1-1 Ogawa-Higashi, Kodaira, Tokyo, 187-8502, Japan. .,Division of Physiology, Faculty of Medicine, Saga University, Saga, 849-8501, Japan.
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7
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Pal R, Bradford BM, Mabbott NA. Prion Disease in the Central Nervous System. Front Cell Neurosci 2022; 16:918883. [PMID: 35875357 PMCID: PMC9302378 DOI: 10.3389/fncel.2022.918883] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 06/13/2022] [Indexed: 01/15/2023] Open
Abstract
Prion diseases such as Creutzfeldt-Jakob disease in humans, bovine spongiform encephalopathy in cattle, and scrapie in sheep, are infectious and chronic neurodegenerative diseases to which there are no cures. Infection with prions in the central nervous system (CNS) ultimately causes extensive neurodegeneration, and this is accompanied by prominent microglial and astrocytic activation in affected regions. The microglia are the CNS macrophages and help maintain neuronal homeostasis, clear dead or dying cells and provide defense against pathogens. The microglia also provide neuroprotection during CNS prion disease, but their pro-inflammatory activation may exacerbate the development of the neuropathology. Innate immune tolerance induced by consecutive systemic bacterial lipopolysaccharide (LPS) treatment can induce long-term epigenetic changes in the microglia in the brain that several months later can dampen their responsiveness to subsequent LPS treatment and impede the development of neuritic damage in a transgenic mouse model of Alzheimer’s disease-like pathology. We therefore reasoned that innate immune tolerance in microglia might similarly impede the subsequent development of CNS prion disease. To test this hypothesis groups of mice were first infected with prions by intracerebral injection, and 35 days later given four consecutive systemic injections with LPS to induce innate immune tolerance. Our data show that consecutive systemic LPS treatment did not affect the subsequent development of CNS prion disease. Our data suggests innate immune tolerance in microglia does not influence the subsequent onset of prion disease-induced neuropathology in mice, despite previously published evidence of this effect in an Alzheimer’s disease mouse model.
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8
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Gonzalez-Gil A, Porell RN, Fernandes SM, Maenpaa E, Li TA, Li T, Wong PC, Aoki K, Tiemeyer M, Yu ZJ, Orsburn BC, Bumpus NN, Matthews RT, Schnaar RL. Human brain sialoglycan ligand for CD33, a microglial inhibitory Siglec implicated in Alzheimer's disease. J Biol Chem 2022; 298:101960. [PMID: 35452678 PMCID: PMC9130525 DOI: 10.1016/j.jbc.2022.101960] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 04/09/2022] [Accepted: 04/11/2022] [Indexed: 12/15/2022] Open
Abstract
Alzheimer's disease (AD) is characterized by accumulation of misfolded proteins. Genetic studies implicate microglia, brain-resident phagocytic immune cells, in AD pathogenesis. As positive effectors, microglia clear toxic proteins, whereas as negative effectors, they release proinflammatory mediators. An imbalance of these functions contributes to AD progression. Polymorphisms of human CD33, an inhibitory microglial receptor, are linked to AD susceptibility; higher CD33 expression correlates with increased AD risk. CD33, also called Siglec-3, is a member of the sialic acid-binding immunoglobulin-type lectin (Siglec) family of immune regulatory receptors. Siglec-mediated inhibition is initiated by binding to complementary sialoglycan ligands in the tissue environment. Here, we identify a single sialoglycoprotein in human cerebral cortex that binds CD33 as well as Siglec-8, the most abundant Siglec on human microglia. The ligand, which we term receptor protein tyrosine phosphatase zeta (RPTPζ)S3L, is composed of sialylated keratan sulfate chains carried on a minor isoform/glycoform of RPTPζ (phosphacan) and is found in the extracellular milieu of the human brain parenchyma. Brains from human AD donors had twofold higher levels of RPTPζS3L than age-matched control donors, raising the possibility that RPTPζS3L overexpression limits misfolded protein clearance contributing to AD pathology. Mice express the same structure, a sialylated keratan sulfate RPTPζ isoform, that binds mouse Siglec-F and crossreacts with human CD33 and Siglec-8. Brains from mice engineered to lack RPTPζ, the sialyltransferase St3gal4, or the keratan sulfate sulfotransferase Chst1 lacked Siglec binding, establishing the ligand structure. The unique CD33 and Siglec-8 ligand, RPTPζS3L, may contribute to AD progression.
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Affiliation(s)
- Anabel Gonzalez-Gil
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Ryan N Porell
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Steve M Fernandes
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Eila Maenpaa
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - T August Li
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Tong Li
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Philip C Wong
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Kazuhiro Aoki
- Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia, USA
| | - Michael Tiemeyer
- Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia, USA
| | - Zaikuan J Yu
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Benjamin C Orsburn
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Namandjé N Bumpus
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Russell T Matthews
- Department of Neuroscience and Physiology, State University of New York Upstate Medical University, Syracuse, New York, USA
| | - Ronald L Schnaar
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
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9
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Pandey MK. The Role of Alpha-Synuclein Autoantibodies in the Induction of Brain Inflammation and Neurodegeneration in Aged Humans. Front Aging Neurosci 2022; 14:902191. [PMID: 35721016 PMCID: PMC9204601 DOI: 10.3389/fnagi.2022.902191] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 04/19/2022] [Indexed: 12/05/2022] Open
Affiliation(s)
- Manoj Kumar Pandey
- Division of Human Genetics, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, United States
- Department of Pediatrics, College of Medicine, University of Cincinnati, Cincinnati, OH, United States
- *Correspondence: Manoj Kumar Pandey,
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10
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Chouhan JK, Püntener U, Booth SG, Teeling JL. Systemic Inflammation Accelerates Changes in Microglial and Synaptic Markers in an Experimental Model of Chronic Neurodegeneration. Front Neurosci 2022; 15:760721. [PMID: 35058740 PMCID: PMC8764443 DOI: 10.3389/fnins.2021.760721] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 11/30/2021] [Indexed: 12/01/2022] Open
Abstract
Bacterial infections are a common cause of morbidity and mortality in the elderly, and particularly in individuals with a neurodegenerative disease. Experimental models of neurodegeneration have shown that LPS-induced systemic inflammation increases neuronal damage, a process thought to be mediated by activation of "primed" microglia. The effects of a real systemic bacterial infection on the innate immune cells in the brain and neuronal networks are less well described, and therefore, in this study we use the ME7 prion model to investigate the alterations in microglia activation and phenotype and synaptic markers in response to a low grade, live bacterial infection. Mice with or without a pre-existing ME7 prion-induced neurodegenerative disease were given a single systemic injection of live Salmonella typhimurium at early or mid-stage of disease progression. Immune activation markers CD11b and MHCII and pro-inflammatory cytokines were analyzed 4 weeks post-infection. Systemic infection with S. typhimurium resulted in an exaggerated inflammatory response when compared to ME7 prion mice treated with saline. These changes to inflammatory markers were most pronounced at mid-stage disease. Analysis of synaptic markers in ME7 prion mice revealed a significant reduction of genes that are associated with early response in synaptic plasticity, extracellular matrix structure and post-synaptic density, but no further reduction following systemic infection. In contrast, analysis of activity-related neuronal receptors involved in development of learning and memory, such as Grm1 and Grin2a, showed a significant decrease in response to systemic bacterial challenge. These changes were observed early in the disease progression and associated with reduced burrowing activity. The exaggerated innate immune activation and altered expression of genes linked to synaptic plasticity may contribute to the onset and/or progression of neurodegeneration.
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Affiliation(s)
| | | | | | - Jessica L. Teeling
- Biological Sciences, Faculty of Environmental and Life Sciences, University of Southampton, Southampton, United Kingdom
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11
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Murchison AG. Hypothesis: Modulation of microglial phenotype in Alzheimer's disease drives neurodegeneration. Alzheimers Dement 2021; 18:1537-1544. [PMID: 34786841 DOI: 10.1002/alz.12503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 09/17/2021] [Accepted: 09/21/2021] [Indexed: 11/11/2022]
Abstract
The pathophysiology of Alzheimer's disease (AD) remains to be elucidated. The amyloid hypothesis holds explanatory power but has limitations. This article suggests that amyloid deposition and increased permeability of the blood-brain barrier are independent early events in the disease process, which together fashion a distinct microglial activation phenotype. Downstream events including, phagocytosis of synapses and persistent glutamate signaling through N-methyl-D-aspartate receptors drive neurodegeneration and tau pathology. This hypothesis draws on several strands of evidence and aims to illuminate several of the unexplained temporal and spatial features of AD.
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12
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There Is Strength in Numbers: Quantitation of Fc Gamma Receptors on Murine Tissue-Resident Macrophages. Int J Mol Sci 2021; 22:ijms222212172. [PMID: 34830050 PMCID: PMC8620503 DOI: 10.3390/ijms222212172] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 10/29/2021] [Accepted: 11/03/2021] [Indexed: 11/17/2022] Open
Abstract
Many of the effector functions of antibodies rely on the binding of antibodies/immune complexes to cellular Fcγ receptors (FcγRs). Since the majority of innate immune effector cells express both activating and inhibitory Fc receptors, the outcome of the binding of immune complexes to cells of a given population is influenced by the relative affinities of the respective IgG subclasses to these receptors, as well as by the numbers of activating and inhibitory FcγRs on the cell surface. A group of immune cells that has come into focus more recently is the various subsets of tissue-resident macrophages. The central functions of FcγRs on tissue macrophages include the clearance of opsonized pathogens, the removal of small immune complexes from the circulation and the depletion of antibody-opsonized cells in the therapy of autoimmunity and cancer. Despite these essential functions of FcγRs on tissue-resident macrophages, an in-depth quantification of FcγRs is lacking. Thus, the aim of our current study was to quantify the various Fcγ receptors on macrophages in murine liver, lung, kidney, brain, skin and spleen. Our study identified a pronounced heterogeneity between FcγR expression patterns of the different tissue macrophages, which may reflect their specialized functions within their unique niches in different organ environments.
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13
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Li Z, Wang Q, Hu H, Zheng W, Gao C. Research advances of biomaterials-based microenvironment-regulation therapies for repair and regeneration of spinal cord injury. Biomed Mater 2021; 16. [PMID: 34384071 DOI: 10.1088/1748-605x/ac1d3c] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2021] [Accepted: 08/12/2021] [Indexed: 12/15/2022]
Abstract
Traumatic spinal cord injury (SCI) usually results in restricted behaviour recovery and even life-changing paralysis, accompanied with numerous complications. Pathologically, the initial injuries trigger a series of secondary injuries, leading to an expansion of lesion site, a mass of neuron loss, and eventual failure of endogenous axon regeneration. As the advances rapidly spring up in regenerative medicine and tissue engineering biomaterials, regulation of these secondary injuries becomes possible, shedding a light on normal functional restoration. The successful tissue regeneration lies in proper regulation of the inflammatory microenvironment, including the inflammatory immune cells and inflammatory factors that lead to oxidative stress, inhibitory glial scar and neuroexcitatory toxicity. Specifically, the approaches based on microenvironment-regulating biomaterials have shown great promise in the repair and regeneration of SCI. In this review, the pathological inflammatory microenvironments of SCI are discussed, followed by the introduction of microenvironment-regulating biomaterials in terms of their impressive therapeutic effect in attenuation of secondary inflammation and promotion of axon regrowth. With the emphasis on regulating secondary events, the biomaterials for SCI treatment will become promising for clinical applications.
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Affiliation(s)
- Ziming Li
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, People's Republic of China
| | - Qiaoxuan Wang
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, People's Republic of China
| | - Haijun Hu
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, People's Republic of China
| | - Weiwei Zheng
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, People's Republic of China
| | - Changyou Gao
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, People's Republic of China.,Dr Li Dak Sum and Yip Yio Chin Center for Stem Cell and Regenerative Medicine, Zhejiang University, Hangzhou, People's Republic of China
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14
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Naughton M, de la Fuente AG. Autoantibodies and microglia: boon or bane? Brain 2021; 144:2231-2233. [PMID: 34382068 DOI: 10.1093/brain/awab269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 07/08/2021] [Indexed: 11/14/2022] Open
Abstract
This scientific commentary refers to ‘MOG autoantibodies trigger a tightly controlled FcR and BTK-driven microglia proliferative response’ by Pellerin et al. (doi:10.1093/brain/awab231).
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Affiliation(s)
- Michelle Naughton
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, Belfast BT9 7BL, UK
| | - Alerie G de la Fuente
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, Belfast BT9 7BL, UK
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15
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Saddala MS, Yang X, Tang S, Huang H. Transcriptome-wide analysis reveals core sets of transcriptional regulators of sensome and inflammation genes in retinal microglia. Genomics 2021; 113:3058-3071. [PMID: 34242709 DOI: 10.1016/j.ygeno.2021.07.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 06/15/2021] [Accepted: 07/02/2021] [Indexed: 01/18/2023]
Abstract
BACKGROUND Retinal microglial cells (RMCs) play crucial roles in maintaining normal visual functions in a healthy eye. However, the underlying mechanisms of RMCs over-activation manifesting the alterations of sensome profile and inflammation state, which contribute to various retinal neurodegenerative diseases, remain elusive. Here, we aimed to identify the core set of sensome and pro-inflammatory genes and their regulators using transcriptome and data mining approaches. METHODS We performed paired-end RNA-sequencing in primary microglial cell cultures treated with TNFα/IFNϒ (10 ng/ml for 12 h) and PBS as a control. Gene enrichment analysis and hierarchical clustering for the differentially expressed transcripts highlight functional pathways and network perturbations. We examined overlaps of the mouse microglial gene expression profiles with the data-mined human sensome and pro-inflammatory marker genes. The core sets of sensome and pro-inflammatory genes were selected and predicted for transcription factors (TFs). The identified TFs in RNA-Seq are validated by the quantitative PCR method. RESULTS TNFα/IFNϒ induced 668 differentially expressed transcripts in retinal microglial cells relative to the control. Furthermore, gene enrichment analysis and the gene expression network revealed activated microglial genes, biological, molecular and inflammatory pathways. The overlapping analysis of the TNFα/IFNϒ-activated microglia genes and the data-mined human gene sets revealed 22 sensome and 61 pro-inflammatory genes. Based on network analysis, we determined 10 genes as the core sets of sensome and pro-inflammatory genes and predicted the top ten TFs that regulate them. The SP110, IRF1, FLI1, SP140 (sensome) and RELB, BATF2, NFKB2, TRAFD1, SP100, NFKB1 (inflammation) are differentially expressed between the TNFα/IFNϒ activated and the non-activated microglia which were validated by quantitative PCR. The outcomes indicate that these transcriptional regulators are highly expressed and may regulate the sensome and inflammatory genes of RMCs and switch them to over-activation. CONCLUSION Our results comprise a powerful, cross-species functional genomics resource for sensome and inflammation of RMCs, which may provide novel therapeutic approaches to prevent retinal neurodegenerative diseases.
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Affiliation(s)
- Madhu Sudhana Saddala
- University of Missouri School of Medicine, Columbia, Missouri, United States of America; Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Xu Yang
- University of Missouri School of Medicine, Columbia, Missouri, United States of America; Aier Eye Institute, Aier Eye Hospital Group, Changsha, Hunan, China
| | - Shibo Tang
- Aier Eye Institute, Aier Eye Hospital Group, Changsha, Hunan, China
| | - Hu Huang
- University of Missouri School of Medicine, Columbia, Missouri, United States of America.
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16
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Pellerin K, Rubino SJ, Burns JC, Smith BA, McCarl CA, Zhu J, Jandreski L, Cullen P, Carlile TM, Li A, Rebollar JV, Sybulski J, Reynolds TL, Zhang B, Basile R, Tang H, Harp CP, Pellerin A, Silbereis J, Franchimont N, Cahir-McFarland E, Ransohoff RM, Cameron TO, Mingueneau M. MOG autoantibodies trigger a tightly-controlled FcR and BTK-driven microglia proliferative response. Brain 2021; 144:2361-2374. [PMID: 34145876 DOI: 10.1093/brain/awab231] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 05/11/2021] [Accepted: 05/24/2021] [Indexed: 12/17/2022] Open
Abstract
Autoantibodies are a hallmark of numerous neurologic disorders, including multiple sclerosis (MS), autoimmune encephalitides and neuromyelitis optica (NMO). While well understood in peripheral myeloid cells, the pathophysiological significance of autoantibody-induced Fc receptor (FcR) signaling in microglia remains unknown, in part due to the lack of a robust in vivo model. Moreover, application of therapeutic antibodies for neurodegenerative disease also highlights the importance of understanding FcR signaling in microglia. Here, we describe a novel in vivo experimental paradigm that allows for selective engagement of Fc receptors within the CNS by peripherally injecting anti-myelin oligodendrocyte glycoprotein (MOG) monoclonal antibodies (mAbs) in normal wild-type mice. MOG antigen-bound immunoglobulins were detected throughout the CNS and triggered a rapid and tightly regulated proliferative response in both brain and spinal cord microglia. This microglial response was abrogated when anti-MOG antibodies were deprived of Fc effector function or injected into Fc γ R knockout mice and was associated with the downregulation of FcRs in microglia, but not peripheral myeloid cells, establishing that this response was dependent on central FcR engagement. Downstream of FcRs, Bruton's tyrosine kinase (BTK) was a required signaling node for this response, as microglia proliferation was amplified in BTKE41K knock-in mice expressing a constitutively active form of BTK and blunted in mice treated with a CNS penetrant small molecule inhibitor of BTK. Finally, this response was associated with transient and stringently regulated changes in gene expression predominantly related to cellular proliferation, which markedly differed from transcriptional programs typically associated with FcR engagement in peripheral myeloid cells. Together, these results establish a physiologically-meaningful functional response to FcR and BTK signaling in microglia while providing a novel in vivo tool to further dissect the roles of microglia-specific FcR and BTK-driven responses to both pathogenic and therapeutic antibodies in CNS homeostasis and disease.
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Affiliation(s)
- Kathryn Pellerin
- Multiple Sclerosis and Neurorepair Research Unit, Biogen, Cambridge, USA
| | - Stephen J Rubino
- Multiple Sclerosis and Neurorepair Research Unit, Biogen, Cambridge, USA
| | - Jeremy C Burns
- Multiple Sclerosis and Neurorepair Research Unit, Biogen, Cambridge, USA
| | | | | | - Jing Zhu
- Translational Biology, Biogen, Cambridge, USA
| | | | | | | | - Angela Li
- Multiple Sclerosis and Neurorepair Research Unit, Biogen, Cambridge, USA
| | | | | | | | | | - Rebecca Basile
- Multiple Sclerosis and Neurorepair Research Unit, Biogen, Cambridge, USA
| | - Hao Tang
- Multiple Sclerosis and Neurorepair Research Unit, Biogen, Cambridge, USA
| | | | - Alex Pellerin
- Multiple Sclerosis and Neurorepair Research Unit, Biogen, Cambridge, USA
| | - John Silbereis
- Multiple Sclerosis and Neurorepair Research Unit, Biogen, Cambridge, USA
| | | | | | | | | | - Michael Mingueneau
- Multiple Sclerosis and Neurorepair Research Unit, Biogen, Cambridge, USA
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17
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Nazareth L, St John J, Murtaza M, Ekberg J. Phagocytosis by Peripheral Glia: Importance for Nervous System Functions and Implications in Injury and Disease. Front Cell Dev Biol 2021; 9:660259. [PMID: 33898462 PMCID: PMC8060502 DOI: 10.3389/fcell.2021.660259] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 03/17/2021] [Indexed: 12/30/2022] Open
Abstract
The central nervous system (CNS) has very limited capacity to regenerate after traumatic injury or disease. In contrast, the peripheral nervous system (PNS) has far greater capacity for regeneration. This difference can be partly attributed to variances in glial-mediated functions, such as axon guidance, structural support, secretion of growth factors and phagocytic activity. Due to their growth-promoting characteristic, transplantation of PNS glia has been trialed for neural repair. After peripheral nerve injuries, Schwann cells (SCs, the main PNS glia) phagocytose myelin debris and attract macrophages to the injury site to aid in debris clearance. One peripheral nerve, the olfactory nerve, is unique in that it continuously regenerates throughout life. The olfactory nerve glia, olfactory ensheathing cells (OECs), are the primary phagocytes within this nerve, continuously clearing axonal debris arising from the normal regeneration of the nerve and after injury. In contrast to SCs, OECs do not appear to attract macrophages. SCs and OECs also respond to and phagocytose bacteria, a function likely critical for tackling microbial invasion of the CNS via peripheral nerves. However, phagocytosis is not always effective; inflammation, aging and/or genetic factors may contribute to compromised phagocytic activity. Here, we highlight the diverse roles of SCs and OECs with the focus on their phagocytic activity under physiological and pathological conditions. We also explore why understanding the contribution of peripheral glia phagocytosis may provide us with translational strategies for achieving axonal regeneration of the injured nervous system and potentially for the treatment of certain neurological diseases.
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Affiliation(s)
- Lynn Nazareth
- Menzies Health Institute Queensland, Griffith University, Southport, QLD, Australia.,Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Nathan, QLD, Australia
| | - James St John
- Menzies Health Institute Queensland, Griffith University, Southport, QLD, Australia.,Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Nathan, QLD, Australia.,Griffith Institute for Drug Discovery, Griffith University, Nathan, QLD, Australia
| | - Mariyam Murtaza
- Menzies Health Institute Queensland, Griffith University, Southport, QLD, Australia.,Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Nathan, QLD, Australia.,Griffith Institute for Drug Discovery, Griffith University, Nathan, QLD, Australia
| | - Jenny Ekberg
- Menzies Health Institute Queensland, Griffith University, Southport, QLD, Australia.,Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Nathan, QLD, Australia.,Griffith Institute for Drug Discovery, Griffith University, Nathan, QLD, Australia
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18
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Chio JCT, Xu KJ, Popovich P, David S, Fehlings MG. Neuroimmunological therapies for treating spinal cord injury: Evidence and future perspectives. Exp Neurol 2021; 341:113704. [PMID: 33745920 DOI: 10.1016/j.expneurol.2021.113704] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 03/01/2021] [Accepted: 03/16/2021] [Indexed: 12/13/2022]
Abstract
Spinal cord injury (SCI) has a complex pathophysiology. Following the initial physical trauma to the spinal cord, which may cause vascular disruption, hemorrhage, mechanical injury to neural structures and necrosis, a series of biomolecular cascades is triggered to evoke secondary injury. Neuroinflammation plays a major role in the secondary injury after traumatic SCI. To date, the administration of systemic immunosuppressive medications, in particular methylprednisolone sodium succinate, has been the primary pharmacological treatment. This medication is given as a complement to surgical decompression of the spinal cord and maintenance of spinal cord perfusion through hemodynamic augmentation. However, the impact of neuroinflammation is complex with harmful and beneficial effects. The use of systemic immunosuppressants is further complicated by the natural onset of post-injury immunosuppression, which many patients with SCI develop. It has been hypothesized that immunomodulation to attenuate detrimental aspects of neuroinflammation after SCI, while avoiding systemic immunosuppression, may be a superior approach. To accomplish this, a detailed understanding of neuroinflammation and the systemic immune responses after SCI is required. Our review will strive to achieve this goal by first giving an overview of SCI from a clinical and basic science context. The role that neuroinflammation plays in the pathophysiology of SCI will be discussed. Next, the positive and negative attributes of the innate and adaptive immune systems in neuroinflammation after SCI will be described. With this background established, the currently existing immunosuppressive and immunomodulatory therapies for treating SCI will be explored. We will conclude with a summary of topics that can be explored by neuroimmunology research. These concepts will be complemented by points to be considered by neuroscientists developing therapies for SCI and other injuries to the central nervous system.
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Affiliation(s)
- Jonathon Chon Teng Chio
- Division of Translational and Experimental Neuroscience, Krembil Research Institute, University Health Network, Toronto, Ontario, Canada; Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada.
| | - Katherine Jiaxi Xu
- Human Biology Program, University of Toronto, Wetmore Hall, 300 Huron St., Room 105, Toronto, Ontario M5S 3J6, Canada.
| | - Phillip Popovich
- Department of Neuroscience, Belford Center for Spinal Cord Injury, Center for Brain and Spinal Cord Repair, The Neurological Institute, The Ohio State University, Wexner Medical Center, 410 W. 10(th) Ave., Columbus 43210, USA.
| | - Samuel David
- Centre for Research in Neuroscience and BRaIN Program, The Research Institute of the McGill University Health Centre, 1650 Cedar Ave., Montreal, Quebec H3G 1A4, Canada.
| | - Michael G Fehlings
- Division of Translational and Experimental Neuroscience, Krembil Research Institute, University Health Network, Toronto, Ontario, Canada; Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada; Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto, Ontario, Canada.
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19
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Graykowski D, Cudaback E. Don't know what you got till it's gone: microglial depletion and neurodegeneration. Neural Regen Res 2021; 16:1921-1927. [PMID: 33642360 PMCID: PMC8343303 DOI: 10.4103/1673-5374.308078] [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] [Indexed: 12/14/2022] Open
Abstract
In the central nervous system, immunologic surveillance and response are carried out, in large part, by microglia. These resident macrophages derive from myeloid precursors in the embryonic yolk sac, migrating to the brain and eventually populating local tissue prior to blood-brain barrier formation. Preserved for the duration of lifespan, microglia serve the host as more than just a central arm of innate immunity, also contributing significantly to the development and maintenance of neurons and neural networks, as well as neuroregeneration. The critical nature of these varied functions makes the characterization of key roles played by microglia in neurodegenerative disorders, especially Alzheimer's disease, of paramount importance. While genetic models and rudimentary pharmacologic approaches for microglial manipulation have greatly improved our understanding of central nervous system health and disease, significant advances in the selective and near complete in vitro and in vivo depletion of microglia for neuroscience application continue to push the boundaries of research. Here we discuss the research efficacy and utility of various microglial depletion strategies, including the highly effective CSF1R inhibitor models, noteworthy insights into the relationship between microglia and neurodegeneration, and the potential for therapeutic repurposing of microglial depletion and repopulation.
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Affiliation(s)
- David Graykowski
- Department of Health Sciences, DePaul University, Chicago, IL, USA
| | - Eiron Cudaback
- Department of Health Sciences, DePaul University, Chicago, IL, USA
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20
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Mabbott NA, Bradford BM, Pal R, Young R, Donaldson DS. The Effects of Immune System Modulation on Prion Disease Susceptibility and Pathogenesis. Int J Mol Sci 2020; 21:E7299. [PMID: 33023255 PMCID: PMC7582561 DOI: 10.3390/ijms21197299] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 09/25/2020] [Accepted: 09/29/2020] [Indexed: 12/17/2022] Open
Abstract
Prion diseases are a unique group of infectious chronic neurodegenerative disorders to which there are no cures. Although prion infections do not stimulate adaptive immune responses in infected individuals, the actions of certain immune cell populations can have a significant impact on disease pathogenesis. After infection, the targeting of peripherally-acquired prions to specific immune cells in the secondary lymphoid organs (SLO), such as the lymph nodes and spleen, is essential for the efficient transmission of disease to the brain. Once the prions reach the brain, interactions with other immune cell populations can provide either host protection or accelerate the neurodegeneration. In this review, we provide a detailed account of how factors such as inflammation, ageing and pathogen co-infection can affect prion disease pathogenesis and susceptibility. For example, we discuss how changes to the abundance, function and activation status of specific immune cell populations can affect the transmission of prion diseases by peripheral routes. We also describe how the effects of systemic inflammation on certain glial cell subsets in the brains of infected individuals can accelerate the neurodegeneration. A detailed understanding of the factors that affect prion disease transmission and pathogenesis is essential for the development of novel intervention strategies.
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Affiliation(s)
- Neil A. Mabbott
- The Roslin Institute & Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, UK; (B.M.B.); (R.P.); (R.Y.); (D.S.D.)
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21
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Accelerated onset of CNS prion disease in mice co-infected with a gastrointestinal helminth pathogen during the preclinical phase. Sci Rep 2020; 10:4554. [PMID: 32165661 PMCID: PMC7067812 DOI: 10.1038/s41598-020-61483-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 02/27/2020] [Indexed: 01/12/2023] Open
Abstract
Prion infections in the central nervous system (CNS) can cause extensive neurodegeneration. Systemic inflammation can affect the progression of some neurodegenerative disorders. Therefore, we used the gastrointestinal helminth pathogen Trichuris muris to test the hypothesis that a chronic systemic inflammatory response to a gastrointestinal infection would similarly affect CNS prion disease pathogenesis. Mice were injected with prions directly into the CNS and subsequently orally co-infected with T. muris before the onset of clinical signs. We show that co-infection with a low dose of T. muris that leads to the development of a chronic T helper cell type 1-polarized systemic immune response accelerated the onset of clinical prion disease. In contrast, co-infection with a high dose of T. muris that induces a T helper cell type 2-polarized immune response did not affect prion disease pathogenesis. The reduced survival times in mice co-infected with a low dose of T. muris on d 105 after CNS prion infection coincided with enhanced astrocyte activation in the brain during the preclinical phase. These data aid our understanding of how systemic inflammation may augment the progression of neurodegeneration in the CNS.
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22
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Local and Systemic Humoral Response to Autologous Lineage-Negative Cells Intrathecal Administration in ALS Patients. Int J Mol Sci 2020; 21:ijms21031070. [PMID: 32041109 PMCID: PMC7037134 DOI: 10.3390/ijms21031070] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 01/31/2020] [Accepted: 02/04/2020] [Indexed: 01/04/2023] Open
Abstract
Amyotrophic lateral sclerosis (ALS) remains a fatal disease with limited therapeutic options. Signaling via neurotrophins (NTs), neuroinflammation, and certain micro-RNAs are believed to play essential role in ALS pathogenesis. Lineage-negative stem/progenitor cells (Lin−) were obtained from bone marrow of 18 ALS patients and administered intrathecally. Clinical assessment was performed using ALS Functional Rating Scale (FRSr) and Norris scale. Protein concentrations were measured in plasma and cerebrospinal fluid (CSF) by multiplex fluorescent bead-based immunoassay. Gene expression in nucleated blood cells was assessed using gene microarray technique. Finally, miRNA expression was analyzed using qPCR in CSF and plasma samples. We observed a significant decrease of C-reactive protein (CRP) concentration in plasma on the seventh day from the application of cells. Gene array results revealed decreased expression of gene sets responsible for neutrophil activation. Further analysis revealed moderate negative correlation between CRP level in CSF and clinical outcome. Brain-derived neurotrophic factor (BDNF) concentrations in both plasma and CSF significantly correlated with the favorable clinical outcome. On a micro-RNA level, we observed significant increase of miR-16-5p expression one week after transplantation in both body fluids and significant increase of miR-206 expression in plasma. Administration of Lin− cells may decrease inflammatory response and prevent neurodegeneration. However, these issues require further investigations.
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23
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Yang C, Hou X, Feng Q, Li Y, Wang X, Qin L, Yang P. Lupus serum IgG induces microglia activation through Fc fragment dependent way and modulated by B-cell activating factor. J Transl Med 2019; 17:426. [PMID: 31864410 PMCID: PMC6925475 DOI: 10.1186/s12967-019-02175-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2019] [Accepted: 12/10/2019] [Indexed: 01/31/2023] Open
Abstract
BACKGROUND Neuropsychiatric manifestations are frequent in patients with systemic lupus erythematosus (SLE), yet the etiology and pathogenesis of brain damage in SLE remains unclear. Because the production of autoantibodies, formation and deposition of immunocomplexes are major serological characteristics of SLE, the elevated level of serum immunoglobulin may contribute to brain tissue injury of SLE. To testify this, in this study, we examined whether immunoglobulin G (IgG) in the serum of SLE patients affects the cellular functions in central nervous system and the potential mechanism. METHODS In vivo intracerebral injection of SLE-serum in mouse was used to activate microglia and the production of pro-inflammatory cytokine was assessed by ELISA. Sera was divided into IgG and IgG depleted fractions, while IgG was further divided into Fc and Fab fragments to examine which part has an effect on microglia. Flow cytometry, immunofluorescence and quantitative PCR (qPCR) were used to verify the synergistic effect of B-cell activating factor (BAFF) on IgG stimulation of microglia. RESULTS We found that IgG in lupus sera can induce M1 activation of brain microglia following intraventricular injection into normal mice, and BAFF facilitates this process. In vitro, we identified that IgG bound to microglia through Fc rather than Fab fragments, and BAFF up-regulated the expression of Fc receptors (FcγR) on the surface of microglia, consequently, promote IgG binding to microglia. CONCLUSION Our results suggest that lupus serum IgG causes inflammatory responses of microglia by involving the Fc signaling pathway and the activity could be up-regulated by BAFF. Accordingly, disruption of the FcγR-mediated signaling pathway and blockade of microglia activation may be a therapeutic target in patients with neuropsychiatric lupus erythematosus.
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Affiliation(s)
- Chunshu Yang
- Department of 1st Cancer Institute, First Affiliated Hospital, China Medical University, Shenyang, 110001 People’s Republic of China
| | - Xiaoyu Hou
- Department of Rheumatology and Immunology, First Affiliated Hospital, China Medical University, Shenyang, 110001 People’s Republic of China
| | - Qianhui Feng
- Department of Rheumatology and Immunology, First Affiliated Hospital, China Medical University, Shenyang, 110001 People’s Republic of China
| | - Yingzhuo Li
- Department of Physiology, School of Life Science, China Medical University, Shenyang, 110122 People’s Republic of China
| | - Xuejiao Wang
- Department of Physiology, School of Life Science, China Medical University, Shenyang, 110122 People’s Republic of China
| | - Ling Qin
- Department of Physiology, School of Life Science, China Medical University, Shenyang, 110122 People’s Republic of China
| | - Pingting Yang
- Department of Rheumatology and Immunology, First Affiliated Hospital, China Medical University, Shenyang, 110001 People’s Republic of China
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D'Argenio V, Sarnataro D. Microbiome Influence in the Pathogenesis of Prion and Alzheimer's Diseases. Int J Mol Sci 2019; 20:E4704. [PMID: 31547531 PMCID: PMC6801937 DOI: 10.3390/ijms20194704] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 09/20/2019] [Accepted: 09/21/2019] [Indexed: 12/14/2022] Open
Abstract
Misfolded and abnormal β-sheets forms of wild-type proteins, such as cellular prion protein (PrPC) and amyloid beta (Aβ), are believed to be the vectors of neurodegenerative diseases, prion and Alzheimer's disease (AD), respectively. Increasing evidence highlights the "prion-like" seeding of protein aggregates as a mechanism for pathological spread in AD, tauopathy, as well as in other neurodegenerative diseases, such as Parkinson's. Mutations in both PrPC and Aβ precursor protein (APP), have been associated with the pathogenesis of these fatal disorders with clear evidence for their pathogenic significance. In addition, a critical role for the gut microbiota is emerging; indeed, as a consequence of gut-brain axis alterations, the gut microbiota has been involved in the regulation of Aβ production in AD and, through the microglial inflammation, in the amyloid fibril formation, in prion diseases. Here, we aim to review the role of microbiome ("the other human genome") alterations in AD and prion disease pathogenesis.
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Affiliation(s)
- Valeria D'Argenio
- Department of Molecular Medicine and Medical Biotechnologies, University of Naples Federico II, via Pansini 5, 80131 Naples, Italy.
- CEINGE-Biotecnologie Avanzate, via G. Salvatore 486, 80145 Naples, Italy.
- Task Force on Microbiome Studies, University of Naples Federico II, 80131 Naples, Italy.
| | - Daniela Sarnataro
- Department of Molecular Medicine and Medical Biotechnologies, University of Naples Federico II, via Pansini 5, 80131 Naples, Italy.
- CEINGE-Biotecnologie Avanzate, via G. Salvatore 486, 80145 Naples, Italy.
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Influence of Lineage-Negative Stem Cell Therapy on Articulatory Functions in ALS Patients. Stem Cells Int 2019; 2019:7213854. [PMID: 31281384 PMCID: PMC6589318 DOI: 10.1155/2019/7213854] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 04/17/2019] [Accepted: 05/08/2019] [Indexed: 01/01/2023] Open
Abstract
Introduction Amyotrophic lateral sclerosis (ALS) is a fatal, neurodegenerative disease, leading to loss of muscle strength and motor control. Impaired speech and swallowing lower the quality of life and consequently may induce acute respiratory failure. Bone marrow-derived stem and progenitor cells (SPCs) may be a valuable source of trophic factors. In this study, we assessed whether adjuvant cellular therapy could affect the levels of selected neurotrophins and proinflammatory factors in the cerebrospinal fluid (CSF) and subsequently prevent the deterioration of articulation. Materials and Methods The study group consisted of 32 patients with sporadic ALS who underwent autologous lineage-negative (Lin−) stem cell intrathecal administration to the spinal canal. Lin− cells were aspirated from the bone marrow and isolated using immunomagnetic beads and a lineage cell depletion kit. Patients were examined for articulatory functions by means of the Voice Handicap Index (VHI) questionnaire and Frenchay Dysarthria Assessment (FDA). In parallel, we carried out the analysis of selected trophic and proinflammatory factors in CSF utilizing multiplex fluorescent bead-based immunoassays. Results Of the 32 patients who received the Lin− progenitor cell therapy, 6 (group I) showed improvement in articulatory functions, 23 remained stable (group II), and 3 deteriorated (group III) on the 28th day. The improvement was particularly noticeable in a better cough reflex, laryngeal time, and dribble reflex. A statistically significant lower level of brain-derived neurotrophic factor (BDNF) was observed on day 0 in group I compared to group II. The CSF concentrations of C-reactive protein (CRP) in group I significantly decreased 7 days after Lin− SPC transplantation. On the contrary, a significant increase in the tumor necrosis factor receptor (TNF-R) level was confirmed among patients from group I with improvement of dribble and coughing reflex, tongue movements, and respiration on the 7th day, as well as on day 28 including dribble reflex solely. Conclusions An application of Lin− stem cells could potentate the beneficial humoral effect. The prevention of deterioration of articulatory functions in ALS patients after applying adjuvant Lin− stem cell therapy seems to be promising. Although the procedure is safe and feasible, it requires further in-depth studies.
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Yanuck SF. Microglial Phagocytosis of Neurons: Diminishing Neuronal Loss in Traumatic, Infectious, Inflammatory, and Autoimmune CNS Disorders. Front Psychiatry 2019; 10:712. [PMID: 31632307 PMCID: PMC6786049 DOI: 10.3389/fpsyt.2019.00712] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 09/05/2019] [Indexed: 01/08/2023] Open
Abstract
Errors in neuron-microglial interaction are known to lead to microglial phagocytosis of live neurons and excessive neuronal loss, potentially yielding poorer clinical outcomes. Factors that affect neuron-microglial interaction have the potential to influence the error rate. Clinical comorbidities that unfavorably impact neuron-microglial interaction may promote a higher rate of neuronal loss, to the detriment of patient outcome. This paper proposes that many common, clinically modifiable comorbidities have a common thread, in that they all influence neuron-microglial interactions. Comorbidities like traumatic brain injury, infection, stress, neuroinflammation, loss of neuronal metabolic integrity, poor growth factor status, and other factors, all have the potential to alter communication between neurons and microglia. When this occurs, microglial phagocytosis of live neurons can increase. In addition, microglia can shift into a morphological form in which they express major histocompatibility complex II (MHC-II), allowing them to function as antigen presenting cells that present neuronal debris as antigen to invading T cells. This can increase risk for the development of CNS autoimmunity, or can exacerbate existing CNS autoimmunity. The detrimental influence of these comorbidities has the potential to contribute to the mosaic of factors that determine patient outcome in some CNS pathologies that have neuropsychiatric involvement, including TBI and CNS disorders with autoimmune components, where excessive neuronal loss can yield poorer clinical outcomes. Recognition of the impact of these comorbidities may contribute to an understanding of the common clinical observation that many seemingly disparate factors contribute to the overall picture of case management and clinical outcome in these complex disorders. In a clinical setting, knowing how these comorbidities can influence neuron-microglial interaction can help focus surveillance and care on a broader group of potential therapeutic targets. Accordingly, an interest in the mechanisms underlying the influence of these factors on neuron-microglial interactions is appropriate. Neuron-microglial interaction is reviewed, and the various mechanisms by which these potential comorbidities influence neuro-microglial interaction are described.
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Affiliation(s)
- Samuel F Yanuck
- Program on Integrative Medicine, Department of Physical Medicine and Rehabilitation, University of North Carolina School of Medicine, Chapel Hill, NC, United States
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27
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Alibhai JD, Diack AB, Manson JC. Unravelling the glial response in the pathogenesis of Alzheimer's disease. FASEB J 2018; 32:5766-5777. [PMID: 30376380 DOI: 10.1096/fj.201801360r] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Alzheimer's disease is a progressive, incurable neurodegenerative disease targeting specific neuronal populations within the brain while neighboring neurons appear unaffected. The focus for defining mechanisms has therefore been on the pathogenesis in affected neuronal populations and developing intervention strategies to prevent their cell death. However, there is growing recognition of the importance of glial cells in the development of pathology. Determining exactly how glial cells are involved in the disease process and the susceptibility of the aging brain provides unprecedented challenges. The present review examines recent studies attempting to unravel the glial response during the course of disease and how this action may dictate the outcome of neurodegeneration. The importance of regional heterogeneity of glial cells within the CNS during healthy aging and disease is examined to understand how the glial cells may contribute to neuronal susceptibility or resilience during the neurodegenerative process.-Alibhai, J. D., Diack, A. B., Manson, J. C. Unravelling the glial response in the pathogenesis of Alzheimer's disease.
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Affiliation(s)
- James D Alibhai
- National Creutzfeldt-Jakob Disease (CJD) Research and Surveillance Unit, University of Edinburgh, Edinburgh, United Kingdom.,UK Dementia Research Institute, University of Edinburgh, Edinburgh, United Kingdom; and
| | - Abigail B Diack
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Roslin, United Kingdom
| | - Jean C Manson
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
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Manich G, Recasens M, Valente T, Almolda B, González B, Castellano B. Role of the CD200-CD200R Axis During Homeostasis and Neuroinflammation. Neuroscience 2018; 405:118-136. [PMID: 30367946 DOI: 10.1016/j.neuroscience.2018.10.030] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 07/27/2018] [Accepted: 10/15/2018] [Indexed: 12/11/2022]
Abstract
Microglia are considered to be the resident macrophages of the CNS and main effector of immune brain function. Due to their essential role in the regulation of neuroinflammatory response, microglia constitute an important target for neurological diseases, such as multiple sclerosis, Alzheimer's or Parkinson's disease. The communication between neurons and microglia contributes to a proper maintenance of homeostasis in the CNS. Research developed in the last decade has demonstrated that this interaction is mediated by "Off-signals" - molecules exerting immune inhibition - and "On signals" - molecules triggering immune activation. Among "Off signals", molecular pair CD200 and its CD200R receptor, expressed mainly in the membrane of neurons and microglia, respectively, have centered our attention due to its unexplored and powerful immunoregulatory functions. In this review, we will offer an updated global view of the CD200-CD200R role in the microglia-neuron crosstalk during homeostasis and neuroinflammation. Specifically, the effects of CD200-CD200R in the inhibition of pro-inflammatory microglial activation will be explained, and their involvement in other functions such as homeostasis preservation, tissue repair, and brain aging, among others, will be pointed out. In addition, we will depict the effects of CD200-CD200R uncoupling in the etiopathogenesis of autoimmune and neurodegenerative diseases. Finally, we will explore how to translate the scientific evidence of CD200-CD200R interaction into possible clinical therapeutic strategies to tackle neuroinflammatory CNS diseases.
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Affiliation(s)
- Gemma Manich
- Department of Cell Biology, Physiology and Immunology, Institute of Neuroscience. Universitat Autònoma de Barcelona, Bellaterra, 08193 Barcelona, Spain
| | - Mireia Recasens
- Department of Cell Biology, Physiology and Immunology, Institute of Neuroscience. Universitat Autònoma de Barcelona, Bellaterra, 08193 Barcelona, Spain
| | - Tony Valente
- Department of Cell Biology, Physiology and Immunology, Institute of Neuroscience. Universitat Autònoma de Barcelona, Bellaterra, 08193 Barcelona, Spain
| | - Beatriz Almolda
- Department of Cell Biology, Physiology and Immunology, Institute of Neuroscience. Universitat Autònoma de Barcelona, Bellaterra, 08193 Barcelona, Spain.
| | - Berta González
- Department of Cell Biology, Physiology and Immunology, Institute of Neuroscience. Universitat Autònoma de Barcelona, Bellaterra, 08193 Barcelona, Spain
| | - Bernardo Castellano
- Department of Cell Biology, Physiology and Immunology, Institute of Neuroscience. Universitat Autònoma de Barcelona, Bellaterra, 08193 Barcelona, Spain
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Obst J, Mancuso R, Simon E, Gomez-Nicola D. PD-1 deficiency is not sufficient to induce myeloid mobilization to the brain or alter the inflammatory profile during chronic neurodegeneration. Brain Behav Immun 2018; 73:708-716. [PMID: 30086399 PMCID: PMC6191933 DOI: 10.1016/j.bbi.2018.08.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 07/18/2018] [Accepted: 08/03/2018] [Indexed: 12/31/2022] Open
Abstract
Innate immune activation is a major driver of neurodegenerative disease and immune regulatory pathways could be potential targets for therapeutic intervention. Recently, Programmed cell death-1 (PD-1) immune checkpoint inhibition has been proposed to mount an IFN-γ-dependent systemic immune response, leading to the recruitment of peripheral myeloid cells to the brain and neuropathological and functional improvements in mice with Alzheimer's disease-like β-amyloid pathology. Here we investigate the impact of PD-1 deficiency on murine prion disease (ME7 strain), a model of chronic neurodegeneration. Although PD-1 was found to be increased in the brain of prion mice, the absence of PD-1 did not cause myeloid cell infiltration into the brain or major changes in the inflammatory profile. However, we observed a slight exacerbation of the behavioural phenotype of ME7 mice upon PD-1 deficiency. These results do not support the possibility of using immune checkpoint blockade as a therapeutic strategy in neurodegenerative disease.
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Affiliation(s)
- J Obst
- Biological Sciences, University of Southampton, United Kingdom
| | - R Mancuso
- Biological Sciences, University of Southampton, United Kingdom
| | - E Simon
- Biological Sciences, University of Southampton, United Kingdom
| | - D Gomez-Nicola
- Biological Sciences, University of Southampton, United Kingdom.
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30
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Pardridge WM, Boado RJ, Patrick DJ, Ka-Wai Hui E, Lu JZ. Blood-Brain Barrier Transport, Plasma Pharmacokinetics, and Neuropathology Following Chronic Treatment of the Rhesus Monkey with a Brain Penetrating Humanized Monoclonal Antibody Against the Human Transferrin Receptor. Mol Pharm 2018; 15:5207-5216. [PMID: 30226787 DOI: 10.1021/acs.molpharmaceut.8b00730] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
A monoclonal antibody (mAb) against the blood-brain barrier (BBB) transferrin receptor (TfR) is a potential agent for delivery of biologic drugs to the brain across the BBB. However, to date, no TfRMAb has been tested with chronic dosing in a primate model. A humanized TfRMAb against the human (h) TfR1, which cross reacts with the primate TfR, was genetically engineered with high affinity (ED50 = 0.18 ± 0.04 nM) for the human TfR type 1 (TfR1). For acute dosing, the hTfRMAb was tritiated and injected intravenously (IV) in the Rhesus monkey, which confirmed rapid delivery of the humanized hTfRMAb into both brain parenchyma, via transport across the BBB, and into cerebrospinal fluid (CSF), via transport across the choroid plexus. For chronic dosing, a total of 8 adult Rhesus monkeys (4 males, 4 females) were treated twice weekly for 4 weeks with 0, 3, 10, or 30 mg/kg of the humanized hTfRMAb via a 60 min IV infusion for a total of 8 doses prior to euthanasia and microscopic examination of brain and peripheral organs. A pharmacokinetics analysis showed the plasma clearance of the hTfRMAb in the primate was nonlinear, and plasma clearance was increased over 20-fold with chronic treatment of the low dose, 3 mg/kg, of the antibody. Chronic treatment of the primates with the 30 mg/kg dose caused anemia associated with suppressed blood reticulocytes. Immunohistochemistry of terminal brain tissue showed microglia activation, based on enhanced IBA1 immuno-staining, in conjunction with astrogliosis, based on increased GFAP immuno-staining. Moderate axonal/myelin degeneration was observed in the sciatic nerve. Further studies need to be conducted to determine if this neuropathology is induced by the antibody effector function, or is an intrinsic property of targeting the TfR in brain. The results indicate that chronic treatment of Rhesus monkeys with a humanized hTfRMAb may have a narrow therapeutic index, with associated toxicity related to microglial activation and astrogliosis of the brain.
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Affiliation(s)
| | - Ruben J Boado
- ArmaGen, Inc. , Calabasas , California 91302 , United States
| | | | - Eric Ka-Wai Hui
- ArmaGen, Inc. , Calabasas , California 91302 , United States
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31
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Rakic S, Hung YMA, Smith M, So D, Tayler HM, Varney W, Wild J, Harris S, Holmes C, Love S, Stewart W, Nicoll JAR, Boche D. Systemic infection modifies the neuroinflammatory response in late stage Alzheimer's disease. Acta Neuropathol Commun 2018; 6:88. [PMID: 30193587 PMCID: PMC6127939 DOI: 10.1186/s40478-018-0592-3] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Accepted: 08/30/2018] [Indexed: 02/04/2023] Open
Abstract
Clinical studies indicate that systemic infections accelerate cognitive decline in Alzheimer’s disease. Animal models suggest that this may be due to enhanced pro-inflammatory changes in the brain. We have performed a post-mortem human study to determine whether systemic infection modifies the neuropathology and in particular, neuroinflammation, in the late-stage of the disease. Sections of cerebral cortex and underlying white matter from controls and Alzheimer's patients who died with or without a terminal systemic infection were immunolabelled and quantified for: (i) Αβ and phosphorylated-tau; (ii) the inflammation-related proteins Iba1, CD68, HLA-DR, FcγRs (CD64, CD32a, CD32b, CD16), CHIL3L1, IL4R and CCR2; and (iii) T-cell marker CD3. In Alzheimer's disease, the synaptic proteins synaptophysin and PSD-95 were quantified by ELISA, and the inflammatory proteins and mRNAs by MesoScale Discovery Multiplex Assays and qPCR, respectively. Systemic infection in Alzheimer's disease was associated with decreased CD16 (p = 0.027, grey matter) and CD68 (p = 0.015, white matter); increased CD64 (p = 0.017, white matter) as well as increased protein expression of IL6 (p = 0.047) and decreased IL5 (p = 0.007), IL7 (p = 0.002), IL12/IL23p40 (p = 0.001), IL15 (p = 0.008), IL16 (p < 0.001) and IL17A (p < 0.001). Increased expression of anti-inflammatory genes CHI3L1 (p = 0.012) and IL4R (p = 0.004) were detected in this group. T-cell recruitment to the brain was reduced when systemic infection was present. However, exposure to systemic infection did not modify the pathology. In Alzheimer's disease, CD68 (p = 0.026), CD64 (p = 0.002), CHI3L1 (p = 0.016), IL4R (p = 0.005) and CCR2 (p = 0.010) were increased independently of systemic infection. Our findings suggest that systemic infections modify neuroinflammatory processes in Alzheimer's disease. However, rather than promoting pro-inflammatory changes, as observed in experimental models, they seem to promote an anti-inflammatory, potentially immunosuppressive, environment in the human brain.
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van Gastel J, Boddaert J, Jushaj A, Premont RT, Luttrell LM, Janssens J, Martin B, Maudsley S. GIT2-A keystone in ageing and age-related disease. Ageing Res Rev 2018; 43:46-63. [PMID: 29452267 DOI: 10.1016/j.arr.2018.02.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 02/06/2018] [Accepted: 02/08/2018] [Indexed: 12/15/2022]
Abstract
Since its discovery, G protein-coupled receptor kinase-interacting protein 2, GIT2, and its family member, GIT1, have received considerable interest concerning their potential key roles in regulating multiple inter-connected physiological and pathophysiological processes. GIT2 was first identified as a multifunctional protein that is recruited to G protein-coupled receptors (GPCRs) during the process of receptor internalization. Recent findings have demonstrated that perhaps one of the most important effects of GIT2 in physiology concerns its role in controlling multiple aspects of the complex ageing process. Ageing can be considered the most prevalent pathophysiological condition in humans, affecting all tissue systems and acting as a driving force for many common and intractable disorders. The ageing process involves a complex interplay among various deleterious activities that profoundly disrupt the body's ability to cope with damage, thus increasing susceptibility to pathophysiologies such as neurodegeneration, central obesity, osteoporosis, type 2 diabetes mellitus and atherosclerosis. The biological systems that control ageing appear to function as a series of interconnected complex networks. The inter-communication among multiple lower-complexity signaling systems within the global ageing networks is likely coordinated internally by keystones or hubs, which regulate responses to dynamic molecular events through protein-protein interactions with multiple distinct partners. Multiple lines of research have suggested that GIT2 may act as one of these network coordinators in the ageing process. Identifying and targeting keystones, such as GIT2, is thus an important approach in our understanding of, and eventual ability to, medically ameliorate or interdict age-related progressive cellular and tissue damage.
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Sumner IL, Edwards RA, Asuni AA, Teeling JL. Antibody Engineering for Optimized Immunotherapy in Alzheimer's Disease. Front Neurosci 2018; 12:254. [PMID: 29740272 PMCID: PMC5924811 DOI: 10.3389/fnins.2018.00254] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 04/03/2018] [Indexed: 12/17/2022] Open
Abstract
There are nearly 50 million people with Alzheimer's disease (AD) worldwide and currently no disease modifying treatment is available. AD is characterized by deposits of Amyloid-β (Aβ), neurofibrillary tangles, and neuroinflammation, and several drug discovery programmes studies have focussed on Aβ as therapeutic target. Active immunization and passive immunization against Aβ leads to the clearance of deposits in humans and transgenic mice expressing human Aβ but have failed to improve memory loss. This review will discuss the possible explanations for the lack of efficacy of Aβ immunotherapy, including the role of a pro-inflammatory response and subsequent vascular side effects, the binding site of therapeutic antibodies and the timing of the treatment. We further discuss how antibodies can be engineered for improved efficacy.
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Affiliation(s)
- Isabelle L Sumner
- Biological Sciences, University of Southampton, Southampton, United Kingdom
| | - Ross A Edwards
- Biological Sciences, University of Southampton, Southampton, United Kingdom
| | | | - Jessica L Teeling
- Biological Sciences, University of Southampton, Southampton, United Kingdom
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Mørch MT, Sørensen SF, Khorooshi R, Asgari N, Owens T. Selective localization of IgG from cerebrospinal fluid to brain parenchyma. J Neuroinflammation 2018; 15:110. [PMID: 29665816 PMCID: PMC5904996 DOI: 10.1186/s12974-018-1159-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 04/11/2018] [Indexed: 11/29/2022] Open
Abstract
Background Encounter of autoantibodies with specific antigens can lead to hypersensitivity reactions and pathology. In multiple sclerosis and neuromyelitis optica spectrum disease (NMOSD), immunoglobulin-G (IgG) deposition has been observed in pathological lesions in the central nervous system. The paradigmatic autoantibodies in NMOSD are specific for the water channel aquaporin-4, localized to astrocytic end-feet at the blood-brain barrier and ependymal cells at the cerebrospinal fluid-brain barrier. We have previously observed that IgG antibodies from NMO patients (NMO-IgG) access brain parenchyma from the cerebrospinal fluid and induce subpial and periventricular NMO-like lesions and blood-brain barrier breakdown, in a complement-dependent manner. Objective To investigate how IgG trafficking from cerebrospinal fluid to brain parenchyma can be influenced by injury. Methods IgG from healthy donors was intrathecally injected into the cerebrospinal fluid via cisterna magna at 1, 2, 4, or 7 days after a distal stereotactic sterile needle insertion to the striatum. Results Antibody deposition, detected by staining for human IgG, peaked 1 day after the intrathecal injection and was selectively seen close to the needle insertion. When NMO-IgG was intrathecally injected, we observed complement-dependent NMO-like pathology (loss of aquaporin-4 and glial fibrillary acidic protein) proximal to the insertion site, with similar kinetics. A fluorescent tracer did not show the same distribution indicating IgG-selective localization. Conclusion These findings suggest that IgG from cerebrospinal fluid localize selectively in brain parenchyma at the site of injury and pathogenic NMO-IgG induce astrocyte pathology at the same location.
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Affiliation(s)
- Marlene Thorsen Mørch
- Neurobiology, Institute of Molecular Medicine, University of Southern Denmark, JB. Winsloewsvej 25, 5000, Odense, Denmark
| | - Sofie Forsberg Sørensen
- Neurobiology, Institute of Molecular Medicine, University of Southern Denmark, JB. Winsloewsvej 25, 5000, Odense, Denmark
| | - Reza Khorooshi
- Neurobiology, Institute of Molecular Medicine, University of Southern Denmark, JB. Winsloewsvej 25, 5000, Odense, Denmark
| | - Nasrin Asgari
- Neurobiology, Institute of Molecular Medicine, University of Southern Denmark, JB. Winsloewsvej 25, 5000, Odense, Denmark.,Department of Neurology, Slagelse Hospital, Institute of Regional Health Research, Slagelse, Denmark
| | - Trevor Owens
- Neurobiology, Institute of Molecular Medicine, University of Southern Denmark, JB. Winsloewsvej 25, 5000, Odense, Denmark.
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Schetters STT, Gomez-Nicola D, Garcia-Vallejo JJ, Van Kooyk Y. Neuroinflammation: Microglia and T Cells Get Ready to Tango. Front Immunol 2018; 8:1905. [PMID: 29422891 PMCID: PMC5788906 DOI: 10.3389/fimmu.2017.01905] [Citation(s) in RCA: 231] [Impact Index Per Article: 38.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2017] [Accepted: 12/13/2017] [Indexed: 12/19/2022] Open
Abstract
In recent years, many paradigms concerning central nervous system (CNS) immunology have been challenged and shifted, including the discovery of CNS-draining lymphatic vessels, the origin and functional diversity of microglia, the impact of T cells on CNS immunological homeostasis and the role of neuroinflammation in neurodegenerative diseases. In parallel, antigen presentation outside the CNS has revealed the vital role of antigen-presenting cells in maintaining tolerance toward self-proteins, thwarting auto-immunity. Here, we review recent findings that unite these shifted paradigms of microglial functioning, antigen presentation, and CNS-directed T cell activation, focusing on common neurodegenerative diseases. It provides an important update on CNS adaptive immunity, novel targets, and a concept of the microglia T-cell equilibrium.
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Affiliation(s)
- Sjoerd T T Schetters
- Department of Molecular Cell Biology and Immunology, VU University Medical Center, Amsterdam, Netherlands
| | - Diego Gomez-Nicola
- Centre for Biological Sciences, University of Southampton, Southampton, United Kingdom
| | - Juan J Garcia-Vallejo
- Department of Molecular Cell Biology and Immunology, VU University Medical Center, Amsterdam, Netherlands
| | - Yvette Van Kooyk
- Department of Molecular Cell Biology and Immunology, VU University Medical Center, Amsterdam, Netherlands
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Som Chaudhury S, Das Mukhopadhyay C. Functional amyloids: interrelationship with other amyloids and therapeutic assessment to treat neurodegenerative diseases. Int J Neurosci 2017; 128:449-463. [PMID: 29076790 DOI: 10.1080/00207454.2017.1398153] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Sutapa Som Chaudhury
- Centre for Healthcare Science and Technology, Indian Institute of Engineering Science and Technology, Shibpur, West Bengal, India
| | - Chitrangada Das Mukhopadhyay
- Centre for Healthcare Science and Technology, Indian Institute of Engineering Science and Technology, Shibpur, West Bengal, India
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Morris G, Puri BK, Frye RE. The putative role of environmental aluminium in the development of chronic neuropathology in adults and children. How strong is the evidence and what could be the mechanisms involved? Metab Brain Dis 2017; 32:1335-1355. [PMID: 28752219 PMCID: PMC5596046 DOI: 10.1007/s11011-017-0077-2] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2017] [Accepted: 07/19/2017] [Indexed: 02/06/2023]
Abstract
The conceptualisation of autistic spectrum disorder and Alzheimer's disease has undergone something of a paradigm shift in recent years and rather than being viewed as single illnesses with a unitary pathogenesis and pathophysiology they are increasingly considered to be heterogeneous syndromes with a complex multifactorial aetiopathogenesis, involving a highly complex and diverse combination of genetic, epigenetic and environmental factors. One such environmental factor implicated as a potential cause in both syndromes is aluminium, as an element or as part of a salt, received, for example, in oral form or as an adjuvant. Such administration has the potential to induce pathology via several routes such as provoking dysfunction and/or activation of glial cells which play an indispensable role in the regulation of central nervous system homeostasis and neurodevelopment. Other routes include the generation of oxidative stress, depletion of reduced glutathione, direct and indirect reductions in mitochondrial performance and integrity, and increasing the production of proinflammatory cytokines in both the brain and peripherally. The mechanisms whereby environmental aluminium could contribute to the development of the highly specific pattern of neuropathology seen in Alzheimer's disease are described. Also detailed are several mechanisms whereby significant quantities of aluminium introduced via immunisation could produce chronic neuropathology in genetically susceptible children. Accordingly, it is recommended that the use of aluminium salts in immunisations should be discontinued and that adults should take steps to minimise their exposure to environmental aluminium.
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Affiliation(s)
- Gerwyn Morris
- Tir Na Nog, Bryn Road seaside 87, Llanelli, Wales, SA15 2LW, UK
| | - Basant K Puri
- Department of Medicine, Imperial College London, Hammersmith Hospital, London, England, W12 0HS, UK.
| | - Richard E Frye
- College of Medicine, Department of Pediatrics, University of Arkansas for Medical Sciences, Arkansas Children's Hospital Research Institute, Little Rock, AR, 72202, USA
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Jay TR, von Saucken VE, Landreth GE. TREM2 in Neurodegenerative Diseases. Mol Neurodegener 2017; 12:56. [PMID: 28768545 PMCID: PMC5541421 DOI: 10.1186/s13024-017-0197-5] [Citation(s) in RCA: 256] [Impact Index Per Article: 36.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 07/20/2017] [Indexed: 12/12/2022] Open
Abstract
TREM2 variants have been identified as risk factors for Alzheimer's disease (AD) and other neurodegenerative diseases (NDDs). Because TREM2 encodes a receptor exclusively expressed on immune cells, identification of these variants conclusively demonstrates that the immune response can play an active role in the pathogenesis of NDDs. These TREM2 variants also confer the highest risk for developing Alzheimer's disease of any risk factor identified in nearly two decades, suggesting that understanding more about TREM2 function could provide key insights into NDD pathology and provide avenues for novel immune-related NDD biomarkers and therapeutics. The expression, signaling and function of TREM2 in NDDs have been extensively investigated in an effort to understand the role of immune function in disease pathogenesis and progression. We provide a comprehensive review of our current understanding of TREM2 biology, including new insights into the regulation of TREM2 expression, and TREM2 signaling and function across NDDs. While many open questions remain, the current body of literature provides clarity on several issues. While it is still often cited that TREM2 expression is decreased by pro-inflammatory stimuli, it is now clear that this is true in vitro, but inflammatory stimuli in vivo almost universally increase TREM2 expression. Likewise, while TREM2 function is classically described as promoting an anti-inflammatory phenotype, more than half of published studies demonstrate a pro-inflammatory role for TREM2, suggesting that its role in inflammation is much more complex. Finally, these components of TREM2 biology are applied to a discussion of how TREM2 impacts NDD pathologies and the latest assessment of how these findings might be applied to immune-directed clinical biomarkers and therapeutics.
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Affiliation(s)
- Taylor R. Jay
- Department of Neurosciences, Case Western Reserve University, School of Medicine, 10900 Euclid Avenue, Cleveland, OH 44106 USA
| | - Victoria E. von Saucken
- Department of Neurosciences, Case Western Reserve University, School of Medicine, 10900 Euclid Avenue, Cleveland, OH 44106 USA
- Stark Neurosciences Research Institute, Indiana University School of Medicine, 320 W 15th Street, Indianapolis, IN 46202 USA
| | - Gary E. Landreth
- Department of Neurosciences, Case Western Reserve University, School of Medicine, 10900 Euclid Avenue, Cleveland, OH 44106 USA
- Stark Neurosciences Research Institute, Indiana University School of Medicine, 320 W 15th Street, Indianapolis, IN 46202 USA
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Glass LJ, Sinclair D, Boerrigter D, Naude K, Fung SJ, Brown D, Catts VS, Tooney P, O'Donnell M, Lenroot R, Galletly C, Liu D, Weickert TW, Shannon Weickert C. Brain antibodies in the cortex and blood of people with schizophrenia and controls. Transl Psychiatry 2017; 7:e1192. [PMID: 28786974 PMCID: PMC5611715 DOI: 10.1038/tp.2017.134] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 05/09/2017] [Accepted: 05/09/2017] [Indexed: 12/17/2022] Open
Abstract
The immune system is implicated in the pathogenesis of schizophrenia, with elevated proinflammatory cytokine mRNAs found in the brains of ~40% of individuals with the disorder. However, it is not clear if antibodies (specifically immunoglobulin-γ (IgG)) can be found in the brain of people with schizophrenia and if their abundance relates to brain inflammatory cytokine mRNA levels. Therefore, we investigated the localization and abundance of IgG in the frontal cortex of people with schizophrenia and controls, and the impact of proinflammatory cytokine status on IgG abundance in these groups. Brain IgGs were detected surrounding blood vessels in the human and non-human primate frontal cortex by immunohistochemistry. IgG levels did not differ significantly between schizophrenia cases and controls, or between schizophrenia cases in 'high' and 'low' proinflammatory cytokine subgroups. Consistent with the existence of IgG in the parenchyma of human brain, mRNA and protein of the IgG transporter (FcGRT) were present in the brain, and did not differ according to diagnosis or inflammatory status. Finally, brain-reactive antibody presence and abundance was investigated in the blood of living people. The plasma of living schizophrenia patients and healthy controls contained antibodies that displayed positive binding to Rhesus macaque cerebellar tissue, and the abundance of these antibodies was significantly lower in patients than controls. These findings suggest that antibodies in the brain and brain-reactive antibodies in the blood are present under normal circumstances.
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Affiliation(s)
- L J Glass
- Schizophrenia Research Laboratory, Sydney, NSW, Australia,Neuroscience Research Australia, Sydney, NSW, Australia
| | - D Sinclair
- Schizophrenia Research Laboratory, Sydney, NSW, Australia,Neuroscience Research Australia, Sydney, NSW, Australia,School of Psychiatry, University of New South Wales, Sydney, NSW, Australia
| | - D Boerrigter
- Schizophrenia Research Laboratory, Sydney, NSW, Australia,Neuroscience Research Australia, Sydney, NSW, Australia
| | - K Naude
- Schizophrenia Research Laboratory, Sydney, NSW, Australia,Neuroscience Research Australia, Sydney, NSW, Australia
| | - S J Fung
- Schizophrenia Research Laboratory, Sydney, NSW, Australia,Neuroscience Research Australia, Sydney, NSW, Australia,School of Psychiatry, University of New South Wales, Sydney, NSW, Australia
| | - D Brown
- St Vincent’s Centre for Applied Medical Research, St Vincent's Hospital, Sydney, NSW, Australia,ICPMR, Westmead Hospital, Westmead, NSW, Australia
| | - V S Catts
- Schizophrenia Research Laboratory, Sydney, NSW, Australia,Neuroscience Research Australia, Sydney, NSW, Australia,School of Psychiatry, University of New South Wales, Sydney, NSW, Australia
| | - P Tooney
- School of Biomedical Sciences and Pharmacy, University of Newcastle, Newcastle, NSW, Australia
| | - M O'Donnell
- School of Psychiatry, University of New South Wales, Sydney, NSW, Australia
| | - R Lenroot
- Schizophrenia Research Laboratory, Sydney, NSW, Australia,Neuroscience Research Australia, Sydney, NSW, Australia,School of Psychiatry, University of New South Wales, Sydney, NSW, Australia
| | - C Galletly
- Discipline of Psychiatry, Adelaide University, Adelaide, SA, Australia,Ramsay Health Care, Adelaide, SA, Australia
| | - D Liu
- Discipline of Psychiatry, Adelaide University, Adelaide, SA, Australia,Northern Adelaide Local Health Network, Adelaide, SA, Australia
| | - T W Weickert
- Schizophrenia Research Laboratory, Sydney, NSW, Australia,Neuroscience Research Australia, Sydney, NSW, Australia,School of Psychiatry, University of New South Wales, Sydney, NSW, Australia
| | - C Shannon Weickert
- Schizophrenia Research Laboratory, Sydney, NSW, Australia,Neuroscience Research Australia, Sydney, NSW, Australia,School of Psychiatry, University of New South Wales, Sydney, NSW, Australia,Schizophrenia Research Laboratory, Neuroscience Research Australia, Barker Street, Randwick, NSW 2031, Australia. E-mail:
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Thom V, Arumugam TV, Magnus T, Gelderblom M. Therapeutic Potential of Intravenous Immunoglobulin in Acute Brain Injury. Front Immunol 2017; 8:875. [PMID: 28824617 PMCID: PMC5534474 DOI: 10.3389/fimmu.2017.00875] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 07/10/2017] [Indexed: 12/31/2022] Open
Abstract
Acute ischemic and traumatic injury of the central nervous system (CNS) is known to induce a cascade of inflammatory events that lead to secondary tissue damage. In particular, the sterile inflammatory response in stroke has been intensively investigated in the last decade, and numerous experimental studies demonstrated the neuroprotective potential of a targeted modulation of the immune system. Among the investigated immunomodulatory agents, intravenous immunoglobulin (IVIg) stand out due to their beneficial therapeutic potential in experimental stroke as well as several other experimental models of acute brain injuries, which are characterized by a rapidly evolving sterile inflammatory response, e.g., trauma, subarachnoid hemorrhage. IVIg are therapeutic preparations of polyclonal immunoglobulin G, extracted from the plasma of thousands of donors. In clinical practice, IVIg are the treatment of choice for diverse autoimmune diseases and various mechanisms of action have been proposed. Only recently, several experimental studies implicated a therapeutic potential of IVIg even in models of acute CNS injury, and suggested that the immune system as well as neuronal cells can directly be targeted by IVIg. This review gives further insight into the role of secondary inflammation in acute brain injury with an emphasis on stroke and investigates the therapeutic potential of IVIg.
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Affiliation(s)
- Vivien Thom
- Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Thiruma V Arumugam
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Tim Magnus
- Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Mathias Gelderblom
- Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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Mabbott NA. Immunology of Prion Protein and Prions. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2017; 150:203-240. [PMID: 28838662 DOI: 10.1016/bs.pmbts.2017.06.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Many natural prion diseases are acquired peripherally, such as following the oral consumption of contaminated food or pasture. After peripheral exposure many prion isolates initially accumulate to high levels within the host's secondary lymphoid tissues. The replication of prions within these tissues is essential for their efficient spread to the brain where they ultimately cause neurodegeneration. This chapter describes our current understanding of the critical tissues, cells, and molecules which the prions exploit to mediate their efficient propagation from the site of exposure (such as the intestine) to the brain. Interactions between the immune system and prions are not only restricted to the secondary lymphoid tissues. Therefore, an account of how the activation status of the microglial in the brain can also influence progression of prion disease pathogenesis is provided. Prion disease susceptibility may also be influenced by additional factors such as chronic inflammation, coinfection with other pathogens, and aging. Finally, the potential for immunotherapy to provide a means of safe and effective prophylactic or therapeutic intervention in these currently untreatable diseases is considered.
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Affiliation(s)
- Neil A Mabbott
- The Roslin Institute & Royal (Dick) School of Veterinary Sciences, University of Edinburgh, Midlothian, United Kingdom.
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43
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Lunetta C, Lizio A, Maestri E, Sansone VA, Mora G, Miller RG, Appel SH, Chiò A. Serum C-Reactive Protein as a Prognostic Biomarker in Amyotrophic Lateral Sclerosis. JAMA Neurol 2017; 74:660-667. [PMID: 28384752 DOI: 10.1001/jamaneurol.2016.6179] [Citation(s) in RCA: 87] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Importance Various factors have been proposed as possible candidates associated with the prognosis of amyotrophic lateral sclerosis (ALS); however, there is still no consensus on which biomarkers are reliable prognostic factors. C-reactive protein (CRP) is a biomarker of the inflammatory response that shows significant prognostic value for several diseases. Objective To examine the prognostic significance of CRP in ALS. Design, Setting, and Participants Patients' serum CRP levels were evaluated from January 1, 2009, to June 30, 2015, in a large cohort of patients with ALS observed by an Italian tertiary multidisciplinary center. Results were replicated in an independent cohort obtained from a population-based registry of patients with ALS. A post hoc analysis was performed of the phase 2 trial of NP001 to determine whether stratification by levels of CRP improves differentiation of responders and nonresponders to the drug. Main Outcomes and Measures Serum CRP levels from the first examination were recorded to assess their effect on disease progression and survival. Results A total of 394 patients with ALS (168 women and 226 men; mean [SD] age at diagnosis, 60.18 [13.60] years) were observed in a tertiary multidisciplinary center, and the analysis was replicated in an independent cohort of 116 patients with ALS (50 women and 66 men; mean [SD] age at diagnosis, 67.00 [10.74] years) identified through a regional population-based registry. Serum CRP levels in the 394 patients with ALS correlated with severity of functional impairment, as measured by total score on the ALS Functional Rating Scale-Revised, at first evaluation (r = -0.14818; P = .004), and with patient survival (hazard ratio, 1.129; 95% CI, 1.033-1.234; P = .007). Similar results were found in the independent cohort (hazard ratio, 1.044; 95% CI, 1.016-1.056; P ≤ .001). Moreover, a post hoc analysis of the phase 2 trial of NP001 using the same CRP threshold showed that patients with elevated baseline CRP levels receiving the higher dose of NP001 had significantly less functional impairment after the treatment period compared with patients with normal baseline CRP, regardless of whether patients with normal CRP levels received NP001 or placebo (3.00 [3.62] vs -7.31 [6.23]; P = .04). Conclusions and Relevance These findings suggest that patients with ALS and elevated serum CRP levels progress more rapidly than do those with lower CRP levels and that this elevation may reflect a neuroinflammatory state potentially responsive to the immune regulators such as NP001.
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Affiliation(s)
| | - Andrea Lizio
- NeuroMuscular Omnicentre, Fondazione Serena Onlus, Milano, Italy
| | - Eleonora Maestri
- NeuroMuscular Omnicentre, Fondazione Serena Onlus, Milano, Italy
| | - Valeria Ada Sansone
- NeuroMuscular Omnicentre, Fondazione Serena Onlus, Milano, Italy2Department of Biomedical Sciences for Health, University of Milan, Milan, Italy
| | - Gabriele Mora
- Department of Neurological Rehabilitation, Fondazione Salvatore Maugeri, Istituto di Ricovero e Cura a Carattere Scientifico, Istituto Scientifico di Milano, Milano, Italy
| | - Robert G Miller
- Forbes Norris MDA/ALS Research and Treatment Center, California Pacific Medical Center, San Francisco, California
| | - Stanley H Appel
- Peggy and Gary Edwards ALS Laboratory, Department of Neurology, Houston Methodist Neurological Institute, Houston, Texas6Houston Methodist Research Institute, Houston, Texas7Department of Neurology, Methodist Neurological Institute, Houston Methodist Hospital, Houston, Texas
| | - Adriano Chiò
- Amyotrophic Lateral Sclerosis Center, "Rita Levi Montalcini" Department of Neuroscience, Neurology II, University of Torino, Turin, Italy9Azienda Ospedaliero-Universitaria Città della Salute e della Scienza, Torino, Italy
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Bradford BM, Tetlow L, Mabbott NA. Prion disease pathogenesis in the absence of the commensal microbiota. J Gen Virol 2017; 98:1943-1952. [PMID: 28708055 PMCID: PMC5656778 DOI: 10.1099/jgv.0.000860] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Prion diseases are a unique group of transmissible, typically sub-acute, neurodegenerative disorders. During central nervous system (CNS) prion disease, the microglia become activated and are thought to provide a protective response by scavenging and clearing prions. The mammalian intestine is host to a large burden of commensal micro-organisms, especially bacteria, termed the microbiota. The commensal microbiota has beneficial effects on host health, including through the metabolism of essential nutrients, regulation of host development and protection against pathogens. The commensal gut microbiota also constitutively regulates the functional maturation of microglia in the CNS, and microglial function is impaired when it is absent in germ-free mice. In the current study, we determined whether the absence of the commensal gut microbiota might also affect prion disease pathogenesis. Our data clearly show that the absence of the commensal microbiota in germ-free mice did not affect prion disease duration or susceptibility after exposure to prions by intraperitoneal or intracerebral injection. Furthermore, the magnitude and distribution of the characteristic neuropathological hallmarks of terminal prion disease in the CNS, including the development of spongiform pathology, accumulation of prion disease-specific protein (PrP), astrogliosis and microglial activation, were similar in conventionally housed and germ-free mice. Thus, although the commensal gut microbiota constitutively promotes the maintenance of the microglia in the CNS under steady-state conditions in naïve mice, our data suggest that dramatic changes to the abundance or complexity of the commensal gut microbiota are unlikely to influence CNS prion disease pathogenesis.
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Affiliation(s)
- Barry M Bradford
- The Roslin Institute and Royal (Dick) School of Veterinary Sciences, University of Edinburgh, Easter Bush EH25 9RG, UK
| | - Laura Tetlow
- The Roslin Institute and Royal (Dick) School of Veterinary Sciences, University of Edinburgh, Easter Bush EH25 9RG, UK
| | - Neil A Mabbott
- The Roslin Institute and Royal (Dick) School of Veterinary Sciences, University of Edinburgh, Easter Bush EH25 9RG, UK
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45
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Abstract
Malignant brain tumors represent one of the most devastating forms of cancer with abject survival rates that have not changed in the past 60years. This is partly because the brain is a critical organ, and poses unique anatomical, physiological, and immunological barriers. The unique interplay of these barriers also provides an opportunity for creative engineering solutions. Cancer immunotherapy, a means of harnessing the host immune system for anti-tumor efficacy, is becoming a standard approach for treating many cancers. However, its use in brain tumors is not widespread. This review discusses the current approaches, and hurdles to these approaches in treating brain tumors, with a focus on immunotherapies. We identify critical barriers to immunoengineering brain tumor therapies and discuss possible solutions to these challenges.
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46
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Michels M, Sonai B, Dal-Pizzol F. Polarization of microglia and its role in bacterial sepsis. J Neuroimmunol 2017; 303:90-98. [PMID: 28087076 DOI: 10.1016/j.jneuroim.2016.12.015] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 12/04/2016] [Accepted: 12/28/2016] [Indexed: 12/14/2022]
Abstract
Microglial polarization in response to brain inflammatory conditions is a crescent field in neuroscience. However, the effect of systemic inflammation, and specifically sepsis, is a relatively unexplored field that has great interest and relevance. Sepsis has been associated with both early and late harmful events of the central nervous system, suggesting that there is a close link between sepsis and neuroinflammation. During sepsis evolution it is supposed that microglial could exert both neurotoxic and repairing effects depending on the specific microglial phenotype assumed. In this context, here it was reviewed the role of microglial polarization during sepsis-associated brain dysfunction.
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Affiliation(s)
- Monique Michels
- Laboratory of Experimental Pathophysiology, Graduate Program in Health Sciences, University of Southern Santa Catarina, Av Universitária, 1105, Criciúma 88806000, SC, Brazil.
| | - Beatriz Sonai
- Laboratory of Experimental Pathophysiology, Graduate Program in Health Sciences, University of Southern Santa Catarina, Av Universitária, 1105, Criciúma 88806000, SC, Brazil.
| | - Felipe Dal-Pizzol
- Laboratory of Experimental Pathophysiology, Graduate Program in Health Sciences, University of Southern Santa Catarina, Av Universitária, 1105, Criciúma 88806000, SC, Brazil; Center of Excellence in Applied Neurosciences of Santa Catarina (NENASC), Graduate Program in Medical Sciences, Federal University of Santa Catarina (UFSC), Florianópolis, SC, Brazil.
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Chauhan P, Hu S, Sheng WS, Prasad S, Lokensgard JR. Modulation of Microglial Cell Fcγ Receptor Expression Following Viral Brain Infection. Sci Rep 2017; 7:41889. [PMID: 28165503 PMCID: PMC5292951 DOI: 10.1038/srep41889] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 01/03/2017] [Indexed: 12/22/2022] Open
Abstract
Fcγ receptors (FcγRs) for IgG couple innate and adaptive immunity through activation of effector cells by antigen-antibody complexes. We investigated relative levels of activating and inhibitory FcγRs on brain-resident microglia following murine cytomegalovirus (MCMV) infection. Flow cytometric analysis of microglial cells obtained from infected brain tissue demonstrated that activating FcγRs were expressed maximally at 5 d post-infection (dpi), while the inhibitory receptor (FcγRIIB) remained highly elevated during both acute and chronic phases of infection. The highly induced expression of activating FcγRIV during the acute phase of infection was also noteworthy. Furthermore, in vitro analysis using cultured primary microglia demonstrated the role of interferon (IFN)γ and interleukin (IL)-4 in polarizing these cells towards a M1 or M2 phenotype, respectively. Microglial cell-polarization correlated with maximal expression of either FcγRIV or FcγRIIB following stimulation with IFNγ or IL-4, respectively. Finally, we observed a significant delay in polarization of microglia towards an M2 phenotype in the absence of FcγRs in MCMV-infected Fcer1g and FcgR2b knockout mice. These studies demonstrate that neuro-inflammation following viral infection increases expression of activating FcγRs on M1-polarized microglia. In contrast, expression of the inhibitory FcγRIIB receptor promotes M2-polarization in order to shut-down deleterious immune responses and limit bystander brain damage.
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Affiliation(s)
- Priyanka Chauhan
- Neurovirology Laboratory, Department of Medicine, University of Minnesota Medical School, Minneapolis, Minnesota, USA
| | - Shuxian Hu
- Neurovirology Laboratory, Department of Medicine, University of Minnesota Medical School, Minneapolis, Minnesota, USA
| | - Wen S Sheng
- Neurovirology Laboratory, Department of Medicine, University of Minnesota Medical School, Minneapolis, Minnesota, USA
| | - Sujata Prasad
- Neurovirology Laboratory, Department of Medicine, University of Minnesota Medical School, Minneapolis, Minnesota, USA
| | - James R Lokensgard
- Neurovirology Laboratory, Department of Medicine, University of Minnesota Medical School, Minneapolis, Minnesota, USA
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48
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Virus Infections on Prion Diseased Mice Exacerbate Inflammatory Microglial Response. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2016; 2016:3974648. [PMID: 28003864 PMCID: PMC5149707 DOI: 10.1155/2016/3974648] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Revised: 09/22/2016] [Accepted: 09/27/2016] [Indexed: 11/18/2022]
Abstract
We investigated possible interaction between an arbovirus infection and the ME7 induced mice prion disease. C57BL/6, females, 6-week-old, were submitted to a bilateral intrahippocampal injection of ME7 prion strain (ME7) or normal brain homogenate (NBH). After injections, animals were organized into two groups: NBH (n = 26) and ME7 (n = 29). At 15th week after injections (wpi), animals were challenged intranasally with a suspension of Piry arbovirus 0.001% or with NBH. Behavioral changes in ME7 animals appeared in burrowing activity at 14 wpi. Hyperactivity on open field test, errors on rod bridge, and time reduction in inverted screen were detected at 15th, 19th, and 20th wpi respectively. Burrowing was more sensitive to earlier hippocampus dysfunction. However, Piry-infection did not significantly affect the already ongoing burrowing decline in the ME7-treated mice. After behavioral tests, brains were processed for IBA1, protease-resistant form of PrP, and Piry virus antigens. Although virus infection in isolation did not change the number of microglia in CA1, virus infection in prion diseased mice (at 17th wpi) induced changes in number and morphology of microglia in a laminar-dependent way. We suggest that virus infection exacerbates microglial inflammatory response to a greater degree in prion-infected mice, and this is not necessarily correlated with hippocampal-dependent behavioral deficits.
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Hayes JM, Wormald MR, Rudd PM, Davey GP. Fc gamma receptors: glycobiology and therapeutic prospects. J Inflamm Res 2016; 9:209-219. [PMID: 27895507 PMCID: PMC5118039 DOI: 10.2147/jir.s121233] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Therapeutic antibodies hold great promise for the treatment of cancer and autoimmune diseases, and developments in antibody–drug conjugates and bispecific antibodies continue to enhance treatment options for patients. Immunoglobulin (Ig) G antibodies are proteins with complex modifications, which have a significant impact on their function. The most important of these modifications is glycosylation, the addition of conserved glycans to the antibody Fc region, which is critical for its interaction with the immune system and induction of effector activities such as antibody-dependent cell cytotoxicity, complement activation and phagocytosis. Communication of IgG antibodies with the immune system is controlled and mediated by Fc gamma receptors (FcγRs), membrane-bound proteins, which relay the information sensed and gathered by antibodies to the immune system. These receptors are also glycoproteins and provide a link between the innate and adaptive immune systems. Recent information suggests that this receptor glycan modification is also important for the interaction with antibodies and downstream immune response. In this study, the current knowledge on FcγR glycosylation is discussed, and some insight into its role and influence on the interaction properties with IgG, particularly in the context of biotherapeutics, is provided. For the purpose of this study, other Fc receptors such as FcαR, FcεR or FcRn are not discussed extensively, as IgG-based antibodies are currently the only therapeutic antibody-based products on the market. In addition, FcγRs as therapeutics and therapeutic targets are discussed, and insight into and comment on the therapeutic aspects of receptor glycosylation are provided.
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Affiliation(s)
- Jerrard M Hayes
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College, Dublin, Ireland
| | - Mark R Wormald
- Department of Biochemistry, Oxford Glycobiology Institute, University of Oxford, Oxford, UK
| | - Pauline M Rudd
- NIBRT Glycoscience Group, National Institute for Bioprocessing, Research and Training, Dublin, Ireland
| | - Gavin P Davey
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College, Dublin, Ireland
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50
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Donaldson DS, Mabbott NA. The influence of the commensal and pathogenic gut microbiota on prion disease pathogenesis. J Gen Virol 2016; 97:1725-1738. [PMID: 27193137 DOI: 10.1099/jgv.0.000507] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Prion diseases are a unique group of transmissible, chronic, neurodegenerative disorders. Following peripheral exposure (e.g. oral), prions often accumulate first within the secondary lymphoid tissues before they infect the central nervous system (CNS). Prion replication within secondary lymphoid tissues is crucial for the efficient spread of disease to the CNS. Once within the CNS, the responses of innate immune cells within it can have a significant influence on neurodegeneration and disease progression. Recently, there have been substantial advances in our understanding of how cross-talk between the host and the vast community of commensal microorganisms present at barrier surfaces such as the gut influences the development and regulation of the host's immune system. These effects are evident not only in the mucosal immune system in the gut, but also in the CNS. The actions of this microbial community (the microbiota) have many important beneficial effects on host health, from metabolism of nutrients and regulation of host development to protection from pathogen infection. However, the microbiota can also have detrimental effects in some circumstances. In this review we discuss the many and varied interactions between prions, the host and the gut microbiota. Particular emphasis is given to the ways by which changes to the composition of the commensal gut microbiota or congruent pathogen infection may influence prion disease pathogenesis and/or disease susceptibility. Understanding how these factors influence prion pathogenesis and disease susceptibility is important for assessing the risk to infection and the design of novel opportunities for therapeutic intervention.
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Affiliation(s)
- David S Donaldson
- The Roslin Institute and Royal (Dick) School of Veterinary Sciences, University of Edinburgh, Edinburgh, UK
| | - Neil A Mabbott
- The Roslin Institute and Royal (Dick) School of Veterinary Sciences, University of Edinburgh, Edinburgh, UK
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